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QUA RTEili.X^ o OURNAL

LITERATURE, AND ART.

JULY TO DECEMBER, 1827.

LONDON:
HENRY COLBURN, NEW BURLINGTON-STREET.

MDCCCXXVII.

CONTENTS

July— Oct. 1827.

Page

On the Beauties contained in the Ovals and in the Elliptic Curves,
both simple and combined, generated from the same Figure or
Disk. By R. R. Reinagle, Esq., R.A. .... 1

On the Art of forming Diamonds into single Lenses for Micro-
scopes. By Mr. A. Pritchard. . . . , . .15

' ' . .' V • r^i^nvered Spring, at Stanley, near Wakefield.

21

^ in this Country. 25

uii itxc D., F.R.S., &c, 39

Dr. Turner s iiYemew^* 0/ u/tc»..: ... 60

Experiments on Audition. Communicated oy Ay, C. Wheat-
stone 67

On the Petromyzon Marinus . . . . . . . .72

Observations upon the Motion of the Leaves of the Sensitive Plant 76

Experiments on the Nature of Labarraques' Disinfecting Soda
Liquid. By M. Faraday, F.R.S., Cor. Mem. Roy. Acad.
Sci. Paris, &c. 84

Hieroglyphical Fragments, with some Remarks on English Gram-
mar. In a Letter to Baron William Von Humboldt. By a
Correspondent 92

Dr. Mac Culloch's * Malaria; an Essay on the Production and

Propagation of this Poisony rewiewed 100

Account of a New Genus of Plants, called Reevesia. By J. Lind-

LEY, Esq., F.L.S., &c. Sec 109

Astronomical and Nautical Collections.

i. Fresnel on the Undulatory Theory of Light . . .113
• ii Rule for the Correction of a Lunar Observation. By Mr.

W. Wiseman, of HuU 135

* De V Influence des Agens Physiques sur la Vie. Par W. F. Ed-
wards, D.M.' &c., reviewed . ., .. . . .137

Account of Professor Carlini's Pendulum Experiments on Mont

Cenis 153

Analysis of the * Transactions of the Horticultural Society, Vol. vii.

Part I.* 159

On the Recent Elucidations of Early Egyptian History . .176

MISCELLANEOUS INTELLIGENCE.
I. Mechanical Science.

Page

1 On the Combined Action of a

Current of Air, and the Pres-
sure of the Atmosphere 193

2 Considerations relative to Capil-

lary Action 194

Page

3 Novel Use of the Plough I97

4 Discovery of Rocks under the

Surface of the Sea 193

5 Paper to resist Humidity .... I'ft^

6 Professor- Amici's Microscopes ift;

a 2

CONTENTS.

II. Chemical Science.

Page

1 On the Specific Heat of Gases 200

2 On the Incandescence & Light

of Lime ..., 201

3 ^Evolution of Heat during the

Compression of Water .... ib.

4 On Electrical Excitation .... ib.

5 Magnetic Repulsion 202

6 Diminished Solubility of Sub-

stances by Heat - '

7 Composition of Cyanic

8 lodous Acid

9 Manganesic Acid ....

10 Heavy Muriatic Ethe

Chloric Ether ... tu.

11 Test for the Presence of Nitric

Acid .205

12 Peculiar Formation of Nitre .. ib.

13 Experhnents on Fluoric Acid

and Fluates ib.

14 Crystallization of Phosphorus. . 206

15 Solution of Phosphorus in Oils ib.

16 On the Inflammation of Powder,

when struck by Brass 207

17 Cementation of Iron by Cast

Iron ib.

18 On the Preparation of Ferro-

prussiate of Potash ib.

19 Sulphocyanide of Potassium in

Saliva 208

20 Decomposition of Sulphate of

Copper, by Tartaric Acid . . ib.

21 Separation of Arsenic from

Nickel, or Cobalt 209

Page

22 Chemical Researches into Cer-

tain Ancient Substances . . 209

23 Compounds of Gold 210

24 On the Bitter Substance pro-

duced by the Action of Ni-
tric Acid on Indigo, Silk,
and Aloes ""'

25 On thp ^--- ; .

1 oi wme 215

"28 Test of the Presence of Opium ib,

29 Denarcotized Laudanum .... ib.

30 Extraction of Morphia from Dry

Poppy Heads 216

31 Preparation of Morphia ib.

32 Easy Method of Obtaining Me-

conic Acid . . . . , 217

33 On a New Vegetable Acid . . ib.

34 Altheine, a New Vegetable

Principle ib,

35 Rheine, a New Substance from

Rhubarb 218

36 On Dragon's Blood, and a New

Substance which it contains ib.

37 Purification of Madder 219

38 On Indigo, and Indigogene . . 220

39 On the Mutual Action of

Ethers, and other Substances 221

40 Faraday's Chemical Manipu-

lation . ib.

III. Natural History.

1 On the Supposed Influence of

the Moon 222

2 Luminous Appearances in the

Atmosphere ib.

3 On the Determination of the

Mean Temperature of the
Air ...• 223

4 Indelible Writing ib,

6 Peculiar Crystals of Quartz . . . ib.
. 6 Native Iron not Meteoric .... 224

7 Native Argentiferous Gold. .. . 225

8 Protheeite, a New Mineral. . . . 226

9 Volcanic Bisulphuret of Copper ib.

10 Fall of the Lake Souwando, in

Russia 227

11 Vegetable Torpor in the Root

of the Black Mulberry Tree 228

12 Method of increasing the Odour

of Roses ib.

13 Pine Apples ib,

14 Mode of Condeasin^ Vegetable

Substances for Ship's Provi-
sions .....: 229

15 Rewards for the Discovery of

Quinia, and for Lithotrity... ib,

16 Upon the Gaseous Exhalations

of the Skin 230

17 Effects of Galvanism in Cases

of Asphyxia by submersion- ib.

18 Recovery from Drowning 231

19 Preservation of Cantharides ... ib.

20 Chloride of Lime in cases of

Burns ih.

21 Cure of Nasal Polypi. 232

22 Bite of the Viper ib.

23 Experiments on the Poison of

the Viper ib,

24 Destruction of Moles ib,

25 On growing Salad Herbs at

Sea 233

26' Chinese Method of Fattening

Fish 234

TO OUR READERS AND CORRESPONDENTS.

The drawings, illustrating the construction of a Blow-pipe, are not
sufficiently accurate to enable us to publish them. Our Correspondent
•will observe that we have noticed another part of his letter.

We regret that we are unable to offer our Correspondent, upon the
subject of Gas Works, any precise information. There can be no doubt
tliat an atmosphere tainted by coal gas is injurious to animal and vege-
table life, but much will depend upon the extent of the contamination,
and other causes, of which our hmits prevent mention. To say nothing
of danger from fire and from explosion, it has always been matter of
surprise to us that gas-works are tolerated by the government in close
and confined situations — that the Thames is suffered still to be polluted
with their offal, and that they are sometimes placed close by the road
side, (as at Brentford,) to the nuisance of every one who passes. These
matters want looking into.

Q. will find an answer to his question, in the *• Gazette of Health" for
last July.

F. R. S. must remain unanswered till after St. Andrew's Day.

Dr. Heinecken's paper is disposed of as he desired.

' Mr. Brande and Mr. Faraday will commence their Lectures and
Demonstrations in Theoretical and Practical Chemistry, in the Labo-
ratory of the Royal Institution, otz Tuesday, the 9th of October, at Nine
in the Morning precisely. Fuiiher particulars, and a Prospectus, maybe
obtained at the Royal Institution, 21, Albemarle- street, or by application
to the Lecturers.

In the Press — A Collection of Chemical Tables, for the use of
Students, in Illustration of the Theory of Definite Proportionals, in
which are shewn the Equivalent Numbers of the Elementary Sub-
stances, with the Weights and Volumes in which they combine, together
with the Composition of their most important Compounds, and the Au-
thorities for their Analysis. By William Thomas Brande.

THE

QUARTERLY JOURNAL

OF

SCIENCE, LITERATURE, AND ART,

On the Beauties contained in the Oval, and in the Elliptic
Curves, both simple and combined, generated from the same
Figure or Disk, By R. R. Reinagle, Esq., R. A,

Being the subject of a Discourse delivered at the Royal Institution of
Great Britain.

After an apposite discourse to introduce the subject, the first
course taken, was to demonstrate the advantages of understand-
ing the right use of geometrical terms in our descriptions of the
•varieties of shape, both in nature and art.

Every thing deserving the title of beautiful, and every grand
object, assume an outline of definite character : these are to be
found in the different classes of geometrical figures ; the former
in undulating fines of elliptic curves, and grandeur in angular
dispositions of figure. All motion assumes a curved direction *.
The primary and leading object of the discourse was to prove
the fact of original beauty : and that a curved line was beautiful
in an abstract point of view, free from all associations. For
this purpose there were designed many diagrams on large black
painted boards.

* A great number of geometrical diagrams were exhibited, from a
single line, to angles, squares, oblongs, circles, ovals, cones, cylinders,
spiral lines, and various serpentine lines, &c*

JULY — OCT. 1827, B

Mr.

Reinagle on the Beauties

The explanation commenced with six or more parallel lines
at equal distances, and equal length, in an horizontal position
to the eye of the audience, Fig. 1 ; and another set of the
same number of lines drawn perpendicular, Fig. 2 : these were

b;?. 1.

i^^. 2.

demonstrated to possess not the slightest character or principle
of beauty in them, either as separate lines, or collectively,
however lAany.

The next diagram consisted of six or more radiating hues
from a centre, Fig. 3, and a corresponding number in an hori*
zontal direction, but of unequal quantities ; they diminished
like a flight of steps. Fig. 4. It was then shown that the first

Fig,Z. Fig.A,

means of combining the six or more lines, which had been first
drawn, so as to please the eye, without creating any geometrical
figure, was the radiating principle. Our eye not only can. tole-
rate that union of lines, but receive the impression as pleasing
in character ; while all lines parallel to each other, being right

contained in the Oval and in the Elliptic Curves, 3

lines, and viewed as a flight of steps, or pile of planks, opposite
the observer, are disagreeable. Upon the former principle it
is, that the rays of the sun, and rays of light generally, are so
attractive and beautiful. It is from this circumstance that right
lines drawn in an inclined position to the plane of the picture,
derive an interest from the angles engendered through the
imagination.

To follow up the principle by regular steps, and to open a
clear view of the laws of beauty in lines, there were traced some
inclined right lines {Fig. 5), with a regular set of right angles
upon it, like the stems of leaves on each side. This exhibited
no sort of beauty, nor any other advantage than mere combi-*
nations of formal angles. The next diagram {Fig. 6) was an
mclined line as before, with similar angular projecting stemis,
to which were added elliptic curves on the upper side of each
branch, that produced the form of a leaf. Fig. 7 was another
inclined line, having oval curves upon it. Both these were
shown to possess principles approaching to beauty, by progres-
sive advances in combination and original structure. Fig, 8

Fig. 5.

Fig. 6. Fig. 7.

Fig. 8.

was an inclined line with the oval curves upon it ; to which a
similar addition of elliptic curves Were adjoined to the stems,

B 2

4 Mr. Reinagle on the Beauties ' '

as in Fig. G. This addition made a new advance towards
beauty. Fig. 9 commenced a more perfect principle of beauty,
having an elliptic stem with oval branches rising from it, as in
the others. If to this, the principle of gradation had been
given, the eye would prefer it ; I mean, by a scale of increase
from the top to the bottom of the projecting stems : and if there
had been superadded the external contour of a lengthened egg,
like the form of a sage leaf, we should, step by step, advance
into the region of beautiful character of exterior shape. Fig,
10 is a retrograde, showing how uncongenial angular forms are
to curved lines, when producing ornament ; at least how little
our eye can bear the angular projections from the elliptic or
oval turned stem. Fig. 11 was a curve of exactly the same
disk, with the same oval stems, to which a small serpentine

Fisr,9,

FigAO,

i^^.ll.

addition was made, expressing a leaf. Of all the last seven dia-
grams, this abounded with the greatest portion of beautiful
lines, and is indisputably the most agreeable and beautiful.
Combinations are like numericals ; many of these forms, placed
together with judgment and discretion, will attract us from the
larger proportion of beauty that meets the eye at once, like a
head of beautiful hair : one hair, however gracefully bent, can-
pot impress us like an entire lock of the hair ; nor will this

contained in the Oval and in the Elliptic Curves. 5

curl charm us as the whole will on the human head. We owe
to construction and combination all our pleasurable feelings of
beauty : no person is allured by a single feature of any species
of objects: but a thousand, or a million, arouses our anxious
notice. Thus, the last diagram of the eUiptic stem and the
foliage upon it, exhibited, by the continuity of curved lines,
the greatest approach to beauty, of all the figures presented to
the notice of the audience.

These preliminary designs opened the way for richer combi-
nations ; but the subject affording such an immense field of
variety, I confined myself to the narrowest limits, and to one
oval disk of seven inches transverse diameter, from which seven
different designs were shown on paper. The first had a variety
of serpentine lines placed at random, all produced by the disk
of the oval just named, and the confluent lines of two such>
placed side by side, or end to end. Fig, 12 ; which oval disk

was put upon the lines to prove the construction. These fines,
without expressing or forming any sort of figure, exhibit a set
of elegant curves, of varied quantities of convex and concave,
with which our eye will be more pleased than any set of right
lines similarly distributed, as in Fig. 13, which follows.

9. Mr. Reinagle on the Beauties

Fig, 13»

Two other diagrams were placed before the company, each a
circle of 12 ovals, from the same disk, revolved upon an axis,
resting upon one end of the transverse diameter, (the length-
ways of the oval,) which figure in the skeleton was a duode-
cagon. Fig. 14 is one of the diagrams ; the ovals folding re-

Fig.U.

gulaiiy over each other. By suppressing the continuity of the
oval disk, where the lines would traverse, a very pleasing figure

contained in the Oval and in the Elliptic Curves, 7

is created. It may be easily converted into foliage, and can
be amazingly varied in principle, by having fewer ovals, and
making them revolve upon an arm or continuation of a line
from the transverse diameter. Fig, 15 is the same diagram,

Fig,l5.

with all the oval lines described, which forms a figure of ele-
gant intricacy ; each member, or curvilinear subdivision, as^
sumes a most agreeable shape : the whole, at the first sight, does
not carry the evidence of being generated from the same disk.
These agreeable figures may be varied to an extraordinary ex-
•tent : the two that were presented were mere examples of some
X)f the numerous changes that any given oval disk may create.

The objects next presented, were three vases of very dis-
similar appearance, all produced from the same diagram
of the oval ; each in a separate drawing. The first was like a
Greek vase with handles ; its character established by employ-
ing certain proportions of quantities, in seven parts. The
body has four parts, the foot or pedestal one ; the neck two.
The handles were l-egulated in the position and projection by
lines drawn from the bottom of the vase, through the ovals
which compose the outline of the two sides ; and passing
through the transverse diameter. These handles were made
from an. oval that was the length of half the line of the
^transverse diameter, Fig. 16. The skeleton of angles that

a

Mr. Reinagle on the Beauties

F?g. 16.

govern the shape of this vase, is a very pretty figure of itself.
The form does not proceed from any caprice of irregularity,
but is consistent with rational organization, and symmetrical
proportions. The figure of the plate sufficiently describes the
mode of making the diagram without entering into the detail.
Fig, 17 represents a tazza with handles; the same disk is

Fig. 17,

appare nt, by the dotted lines that made the first vase. The ovals

contained inihe Oval and in the Elliptic Curves,

Fig. 18

are placed right and left of a central perpendicular line, dividing
the cup in two parts ; the transverse diameters meet in one line
parallel to the base of the tazza ; a dotted outline expresses the
angular position of the handles : the concave lip of the tazza is
made by the same oval disk, whose transverse diameter leads to
the under line of the folding edge of the cup. The leg of the
tazza is produced by the same small disk that served for the
handles of the first vase. The body of the vase and the leg
form two equal parts; the whole upper extent ought to be
seven parts, so that it is seven and two * ; the width of the
base of the leg measures two parts, and the altitude three, of
the seven parts. These proportions cannot produce any other
than agreeable appearances, apply them as we may.

The third vase, exhibited an Hebe
cup, with a handle, which presented
a totally different appearance in form
to the two previous ones. It was
proportioned by similar principles:
the larger disk made the body, in-
clined right and left upon the end of
the oval. The neck and the leg
were both made from the smaller
oval disk; the dotted lines to the
ovals of the leg sufficiently show the
fact. The handle and concave lip
of the cup were made by an appli-
cation of the same disk. The alti-
tude contained four parts. The body
two parts, the leg one part, and the
neck one other part; the handle
rises one-eighth above : every por-
tion of this figure is created by
the two disks previously named.
The foliage rises from below and
descends from above, one-fourth of the whole height of the body

* The whole extent of the tazza, includingtheprojection of the handles,
should be seven parts ; and the height of the vase two of such seven
parts, • '

10

Mr. Reinagle X)n the Beauties

to the commencement of the concavity of the neck, where the
beading runs round.

I remarked, that by adhering to regular proportional quan-
tities of 1 and 2, 3 and 5, 2 and 5, 7 and 5, 7 and 2, Sec,
and using elliptic disks or curves, very great beauties are
derived.

A skeleton of the tazza in angles was drawn on a black
painted board, together with oval disks placed upon those lines,
which clearly demonstrated the whole system of the construc-
tion. The explanation of these various diagrams necessarily
involved a circumstantial description of each created figure,
which were thoroughly analysed. Quantity and variety were
particularly dwelt upon, as absolutely necessary to the produc-
tion of perfect beauty ; equalities being unfriendly to that sym-
metry which accords with nature. Some other diagrams were
drawn, to show the inelegant appearance of radiating lines from
^e concave or convex half of an oval or an ellipse. Fig. 19 :

Fiic. 19.

but by drawing another convex half of an oval, and placing those
lines as tangents, greater beauty was formed by the alternate
changes and varieties of inclination of each tangent. Fig. 20.

Fig. 20.

This was capable of an immediate adaptation to elegant vege-

. contained in the Oval and in the Elliptic Curves, IL.

tation; a few convex and concave elliptic curves added to
each tangent, produced an ear of barley, or an ear of rye, the
elegant construction of which, is rarely noticed in our remarks
on nature, Fig, 21.

Fig, 21.

The discussion on these various designs being concluded, some
important compositions of three great and renowned painters
were produced, to corroborate what had been advanced in sup-
port of the native beauty of the oval and ellipse. Raphael's
grand composition of the dispute on the Sacrament is in three
grand oval curves.

The Doctors of the Church on the ground plan are ranged in
an oval convex line ; and the heavenly Choirs engage two con-
cave oval shapes of the same proportion, but of unequal quan-
tities. This is also a proof of a composition of parts, bearing
two to one.

The facility of expressing such a composition, by being geo-
metrical, is extremely easy.

The second illustration was the Aurora, by Guido, of the
Aldobrandini palace. This was pointed out to depend upon
an oval curve, and continued curvilinear details : the striking
beauty of this fine composition is owing to its great and simple
elliptic curve, which includes the whole group ; the attendant
hours have the principle of radiating to a centre of the oval :
thus harmonizing and uniting forms congenial both to principle
and nature.

The third grand composition was by Rubens, the Coronation
ceremony of Mary de Medicis, one of the grand Luxemburg
pictures.

This very fine composition is contained in an oval con-

12

Mr. Reinagle on the Beauties

cave curve, and the figures in several points radiate to a
centre. Some of the group pass the great leading line, but
only to the degree and with the licence that a genius can effect,
which destroys the too great, and the too palpable construction
of the composition. The allegorical figures of Fame and Genius
hovering over the royal personage, establish a centre to the
oval, which prevents a void that would have been weak in the
composition.

Three designs were next produced from Etruscan vases, to
carry the evidence further, and to show the original source of
the demonstrations of beauty in Grecian art. One was a cha-
rioteer driving a pair of magnificent horses of the highest spirit,
Fig. 22. The composition is elliptic, and serpentine within.

Fig, 22.

Mt/f

The youthful conductor of the steeds is in a crescent or
boat-shaped car, and his form is elegantly bent to meet the
action and motion ; his mantle flows behind in curved and ser-
pentine folds, expressing the wind occasioned by the velocity of
action. A more graceful or beautiful group and composition
cannot be imagined.

The next design was a female in an elegant and very gentle
serpentine action of the figure. Every portion of the outlines
was elegant, from the varied succession of convexity and con-»
cavity ; not a single angle could be traced throughout the whole

contained in the Oval and in the Elliptic Curves, 13

of this beautiful creature. She held in her left arm a very
handsome oval vase ; and in the other a sort of scarf with
ribands, all serpentine in form. By her side is placed a young
man selected from another Etruscan design.

Fig. 23.

The line of this figure was the outline of an ellipse ; it is
•perfection in every respect ; and the grace was shown to de-
pend upon gentle curved lines of convex and concave, alter-
nately blended, and confluent. The motion of ships at sea is
described in gentle elliptic curves ; the wings and plumage of
birds assume the oval and elliptic curves ; all the fibres of their
feathers have that form ; some flattened, others more rounded :
the pine-apple and numberless fruits have all an oval character
of outline.

Many4ake the character of eggs, pointed at one end, and
large and blunt at the other extremity. The leaves of trees

14 Mr. Reinagle on Oval and Elliptic Curves.

have the oval shape more than any other ; the bend of the
branches, and the whole external form of many trees is oval.

There is no form of created things which may not be found
to correspond in all its dependent shapes to ovals and ellipses
of various disks, even objects which at first sight seem to con-
tradict the possibility of meeting this system.

The lecture was closed by some extracts and quotations from
Lomazzo, Dryden, Hogarth, Du Fresnoy, and the Abbe du
Bos ; the tendency of which was to show that lines had been
mentioned, and had been written upon without any explanation
given that could lead to certain conclusions. That all these
authors attributed to supreme genius alone, and something of
the divinely inspired character in artists, the power to produce
those indescribable lines that affect the human eye so strongly.
These lines I described as belonging to the oval and the ellipsis,
and the confluent lines by conjunction and combination ; that
these indescribable lines, which from Plato to Dryden had
never been detected or obtained a name ; that puzzled all
equally alike, are those alone I attempted, and I believe
proved in this lecture, to be the elliptic combinations.

I stated that the great Greek artists confined themselves to
certain rules and principles of unerring consequences in the
production of beauty, grace, or grandeur in their figures ; that
all their compositions depended upon the same species of rule
and order. I pointed out, that fashion is in all countries the
destroyer of taste, that it unfits the mind for fixed principles ;
that where it dominates, there taste will be always fluttering
and never settle, nor have a sure dominion. The Greeks,
having no such vile tormentor to divert them from a pure course
in their progress, arrived at the summit of perfection in every
scientific pursuit, by following sure principles as their guides,
and by never abandoning a path traced by nature, and matured
by the most sublime philosophy.

15

On the Art of forming Diamonds into single Lenses for

Microscopes. — By Mr. A. Pritchard.

[Communicated by Dr. Goring.]

Of the various improvements in Microscopes originated by
Dr. Goring, that which he conceives to be the most important
is the construction of single magnifiers from adamant. The
details relative to this novel class of instruments, I have been
induced to lay before the public. Single microscopes natu-
rally aplanatic, or at least sufficiently so for practical pur-
poses, possess an incontestable superiority over all others, and
must be recognised by the scientific as verging towards the
ultimatum of improvement in magnifying glasses. The ad*
vantages obtained by the most improved compound engi-
Bcopes over single microscopes resolve themselves into the at-
tainment of vision without aberration with considerable angles
of aperture; but against this must be set the never-to-be-forgot-
ten fact, that they only show us a picture of an object instead
of nature itself; now a Diamond Lens shows us our real
object without any sensible aberration like that produced by
glass lenses ; and we are entitled, I think, to expect new dis-
coveries in miscrosopic science, even at this late period, from
very deep single lenses of adamant*. I shall not fatigue my

♦ It seems generally admitted that, within a certain range of power not
exceeding that of a lens of s'cth of an inch focus, the beauty and truth of
the vision given by the new compound microscopes cannot be equalled
by that of any single instrument, at least of glass. It is no less true,
however, that the picture of the compounds, however perfect, is not
like a real object, will not admit of amplification beyond a certain
point with advantage. Under the action of very deep eye-glasses, the
image of opaque objects especially, first loses its strong, well-deter-
mined outline— then grows soft and nebulous, and finally melts away in
shadowy confusion. Let the experiment be made of raising the power
of a compound up to that of a Jgth inch lens — then try it against the
single microscope of that power (having, of course, the utmost opening
the nature of the object viewed will permit). The observer, if open to
conviction, will soon be taught the superior efficacy of the latter — for it
will show the lines on the dust of Menelaus with such force and viva*-
city, that they will always be apparent without any particular manage^
merit of the light— nor can their image be extinguished by causing the
illumination to be directed truly through the axis of the lens (as it al-
uays may in the compounds), A due consideration of the teeth and
inequalities on the surface of a human hair, together with the transverse

16 Mr. Pritchard on Diamond

readers by describing the difficulties which were encountered
in the prosecution of the design of making diamond lenses.
Nature does not seem to permit us to produce any thing of
surpassing excellence without proportional effort, and I shall
simply say, that in its infancy the project of grinding and
polishing the refractory substance of Adamant was far more
hopeless than that of making achromatic glass lenses of 0.2 of
an inch focus. I conceive it just to state that Messrs. Rundell
and Bridge, of Ludgate-hill, had, at the time of the com-
mencement of my labours, many Dutch diamond cutters at
work, and that the foreman, Mr. Levi, with all his men, assured
me, that it was impossible to work diamonds into spherical
curves ; the same opinion was also expressed by several others
who were considered of standard authority in such matters.

Notwithstanding this discouragement, in the summer of
the year 1824, I was instigated by Dr. Goring (at his ex-
pense) to undertake the task of working a diamond lens ;
(being then under the tuition of Mr. C. Varley, who was
however at that time absent.) For this purpose, Dr. G,
forwarded to me a brilliant diamond, which, contrary to the
expectation of many, was at length ground into a spherical

connecting fibres between the lines on the scales of the curculio imperialism
viewed as opaque objects, will suffice to complete the illustration of the
subject ; though the last object is not to be well seen by that kind of light
which is given by silver cups — and a single lens of e^gth inch focus can
of course have no other. The effectiveness and penetrating faculties of
simple magnifiers are invariably increased by an accession of power
however great — that of compounds seems to be deteriorated beyond cer-
tain limits. An opinion may be hazarded that the achromatics and reflec-
tors yet made do not really surpass the efficacy of equivalent single lenses ^
even of glass, when their power exceeds that of a 5^0 th lens, from 201th to
4'oth the vision may be about equal — but from ^'oth upwards infinitely
inferior.

The superior light of the single refraction can need no comment — and
it is evident that there must be a degree of power at which that of the
compounds will become too dim and feeble for vision, — while that of the
single instrument will still retain a due intensity. For these reasons it
is conceived that the close and penetrating scrutiny of lenses of diamond
of perhaps only the ^ioth inch focus, and an equal aperture (which their
very low aberration would easily admit of,) must enable us to see further
into the arcana of nature than we have yet been empowered to do. Glass
globules of 5U(jth inch focus and indeed much deeper have been executed ;
but the testimony of lenses of diamond would certainly be far more re-
spectable, and is at least worthy of trial and examination. — C. R. G.

Lenses for Microscopes, 17

figure, and examined by Mr. Levi, who expressed great
astonishment at it, and added that he was not acquainted with
any means by which that ligure could have been effected :
unfortunately this stone was irrecoverably lost. Mr. Varley
having returned from the country, becoming now thoroughly
heated with the project, permitted me to complete another
diamond, which had been presented to me by Dr. G. : this
is a plano-convex of about ihe^^jth of an inch focus : it was
not thought advisable to polish it more than sufficed to enable
us to see objects through it, because several flaws, before
invisible, made their appearance in the process of polishing.
In spite of all its imperfections, it plainly convinced us of the
superiority which a perfect diamond lens would possess by its
style of performance, both as a single magnifier and as the
object lens of a compound microscope. After the completion
of my articles with Mr. V., being entirely under my own com-
mand, I devoted some time to the formation of a perfect
diamond lens, and have at length succeeded in completing a
double convex of equal radii of about ^th of an inch focus,
bearing an aperture of ^yh of an inch with distinctness on
opaque objects, and its entire diameter on transparent ones ;
it was finished at the conclusion of last year. The date of its
final completion has by many been considered a remarkable
epoch in the history of the microscope, being the first perfect
one ever made or thought of in any part of the world*. I think
it sufficient to say of this adamantine lens that it gives vision
with a trifling chromatic aberration, but in other respects
exceedingly like that of Dr. G.'s Amician reflector, but
without its darkness: for it is quite evident that its light
must be superior to that of any compound microscope whatever,
acting with the same power and the same angle of aperture.
The advantage of seeing an object without aberration by

* In Dr. Brewster's treatise on new Philosophical instruments, Book 5,
chan. 2, Pag^e 403— Account of a new compound Microscope for objects
of Natural History — is the followinjr passage : *' We cannot therefore ex-
*' pect any essential improvement in the single microscope, unless from
I* the discovery of some transparent substance, which like the diamond
*' combines a high refractive with a low dispersive power." From which
it seems certain that the Doctor never contemplated the possibility of
working upon the substance of the diamond, though he must have been
aware of its valuable properties.

JULY— OCT. 1827. C

18 Mr. Pritchard on Diamond

the interposition of but a single magnifier, instead of looking
at a picture of it (however perfect) with an eye-glass, must
surely be duly appreciated by every person endowed with
ordinary reason. It requires little knowledge of optics to be
convinced that the simple unadulterated view of an object must
enable us to look farther into its real texture, than we can see
by any artificial arrangement whatever ; it is like seeing an
action performed instead of a scenic representation of it, or
being informed of its occurrence by the most indisputable and
accurate testimony.

Previous to grinding a diamond into a spherical figure, it is
absolutely necessary that it should be ground flat, and parallel
on both sides (if not a Laske or plate diamond), so that we
may be enabled to see through it, and try it as opticians try a
piece of flint glass : without this preparatory step, it will be ex-
tremely dangerous to commence the process of grinding, for
many diamonds give a double, or even a species of triple refrac-
tion, forming two or three images of an object ; this polariza-
tion of the light, arising from the primitive form of the crystal,
of course totally unfits them for making lenses*. I need not
observe, that it must he chosen of the finest water, and free
from all visible flaws when examined by a deep magnifier. It
was extremely fortunate for diamond lenses that the first made
was free from the defect of double vision, otherwise diamonds
en masse might at once have been abandoned as unfit for opti-
cal purposes. The cause why some stones give single vision,
and others several peculiar refractions, may also arise from
different degrees of density or hardness occurring in the same
stone. Diamond-cutters are in the habit of designating stones
male and female, sometimes a he and she (as they have it)
are united in the same gem, — their he means merely a hard
stone, and their she a soft one. When a diamond which will
give several refractions is ground into a spherical figure and
partially polished, it is seen by the microscope to exhibit a

* There are fourteen different crystalline forms of the diamond, and of
this number, from the laws which govern the polarization of light, the
octohedron and truncated cube are probably the only ones that will give
single vision. It is unfortunately very difficult to procure rough dia-
monds in this coimtry, so we are compelled to use stones already cut,
and to subject them to trial in the way mentioned in the text.

Lenses for Microscopes. 19

peculiar appearance of an aggregation of minute shivery cris-
tallized flaws, sometimes radiated and sometimes in one direc-
tion, which can never be poHshed out : I beheve I could dis-
stinguish with certainty a bad lens from a good one by this
phenomenon without looking through it*. Precious stones,
from their crystalized texture, are liable to the same defects for
optical purposes as diamonds.

Having ascertained the goodness of a stone it must next be pre-
pared for grinding ; it will in many cases be advisable to make
diamond lenses plano-convex, both because this figure gives a
very low aberration, and because it saves the trouble of grinding
one side of the stone. It must never be forgotten, that it may
be possible to neutralize the naturally low spherical aberration
of a diamond lens by giving it an improper figure, or by the
injudicious position of its sides in relation to the radiant.
When the lens is to be plano-convex, cause the flat side to be
polished as truly plane as possible, without ribs or scratches ;
for this purpose the diamond should be so set as to possess the
capability of being turned round, that the proper direction with
respect to the laminae may be obtained : when the flat side is
completed, let the other side be worked against another dia-
mond, so as to be brought into a spherical figure by the abra-
sion of its surface. When this is accomplished, a concave tool
of cast iron must be formed of the required curve in a lathe,
having a small mandril of about j^ths of an inch in diameter,
and a velocity of about 60 revolutions per second ! The dia-
mond must now be fixed by a strong hard cement (made of
equal parts of the best shell lac and pumice-stone powder, care-
fully melted together without burning) to a short handle, and
held by the fingers against the concave tool while revolving.
This tool must be paved by diamond povvder, hammered into it
by an hardened steel convex punch : vvhen the lens is uniformly
ground all over, very fine sifted diamond-dust carefully washed
in oil must be applied to another iron concave tool (I may here
remark, that of all the metals which I have used for this pur-
pose soft cast iron is decidedly to be preferred) : this tool must

* As many amateurs of science might take an interest in the inspection
of the pecuhar etfect these lenses have on transmitted light, I shall be
happy to exhibit them, as also the pertfect lens.

C 2

20 Mr. Pritchard on Diamond

be supplied with the finest washed powder till the lens is com-
pletely polished. During the process of grinding, the stone
should be examined by a magnifying lens, to ascertain whether
the figure is truly spherical ; for it sometimes will occur that
the edges are ground quicker than the centre, and hence it will
assume the form of a conoid, and thus be rendered unfit for
microscopic purposes.

The spherical aberration of a diamond lens is extremely small,
and when compared with that of a glass lens the difference is
rendered strikingly apparent. This diminution of error in the
diamond arises from the enormous refractive power possessed
by this brilliant substance, and the consequent increase of am-
plification, with very shallow curves. The longitudinal aberra-
tion of a plano-convex diamond lens is only 0.955, while that of
a glass one of the same figure is 1.166 ; both numbers being
enumerated in terms of their thickness, and their convex surfaces
exposed to parallel rays. But the indistinctness produced by
lenses, arises chiefly from every mathematical point on the sur-
face of an object being spread out into a small circle ; these
circles, intermixing with each other, occasion a confused view
of the object. Now this error must necessarily be in the ratio
of the areas of these small circles, which being respectively as
the squares of their diameters, the lateral error produced by
a diamond lens will be 0.912, while that of a glass lens of like
curvature is 2.775 ; but the magnifying power of the diamond
lens will be to that of the glass as 8 to 3, their curves being
similar ; (or, in other words, the superficial amplification of an
object, with the perfect diamond lens before mentioned, is
22500 times, while a similar magnifier, made of glass, amplifies
only 3136 times, reckoning 6 inches as the standard of distinct
vision :) thus the diamond will enable us to gain more power
than it is possible to procure by lenses of glass, for the focal
distance of the smallest glass lens which can be well made is
about the jr^Qih. of an inch, while that of a diamond, worked in
the same tools, would be only the -^Jo^h of an inch.

If we wish to compare the aberrations of the two lenses when
of equal power, the curvature of the glass must be increased ;
and as it is well known the lateral aberration increases inversely
as the square of the radius, (the aperture and position remain-

Lenses for Microscopes. 21

ing the same,) the aberration of the diamond lens will only be
about -j^th of that produced by the glass one, even when their
thickness is the same ; but as the curvature of the diamond is
less, the thickness may be greatly diminished.

The chromatic dispersion of the adamant being nearly as low
as that of water, its effects in small lenses can barely be appre-
ciated by the eye, even in the examination of that valuable class
of test objects, which require enormous angles of aperture to be
rendered visible, which it is evident must be of easier attainment
by diamond magnifiers than by any other sort of microscope.

A mathematical investigation of the spherical aberration of
the diamond when formed into lenses, I hope to lay before the
public at a future opportunity. The comparative numbers
here taken from the longitudinal aberration are, I believe,
sufficiently accurate for practical purposes.

18, Picket' Street i Strand,

Analysis of a newly -discovered Spring, at Stanley, near
Wakefield,^-By Mr. William West.

Mineral springs, dependent for their characteristic properties
on carbonate of soda, appear to have been little noticed by
chemists, and to have been still less attended to as curative
means ; at least in proportion to the multitude of cases in which
that substance is administered in various other forms. Indeed
the inference to be drawn from the silence respecting the
modes of analysis adapted to such waters in our best elementary
treatises, is that they have hitherto been very seldom met with.
In one district, however, of Yorkshire, carbonate of soda is of
frequent occurrence ; it is found in the ordinary springs ; often
at the same time with substances with which, in artificial solu-
tions, or when concentrated, it. would be considered wholly
incompatible ; while at other times it is the predominant, or
the only remarkable saline constituent. An analysis of a water
of this kind, known by the name of the Holbeck Spa, has
lately been published in the Annals of Philosophy, by my friend
E. S. George; similar springs are found, I understand, as far^

22 Mr. West on a newly 'discovered Spring

westward as Bradford ; they are numerous from the borings
in and near Holbeck ; while eight miles south, a water si-
milar in its character, but differing in containing about twice
as much alkali iu the same measure, has been discovered at
Stanley.

About two miles from Wakefield, near the Aberford or York
road, is an ancient mansion called Hatfield Hall ; near the
park or inclosure of which, in boring for coal, the spring in
question suddenly gushed up, when the workmen had got to
the depth of eighty yards, and has continued to run spontane-
ously, in all seasons, at the rate of six gallons per minute.

The water at the spring is limpid and very sparkling ; the
portion which is allowed to escape, deposits upon the trough
and in the channel through Avhich it runs a quantity of sulphur ;
the smell is that of sulphuretted hydrogen ; the taste, from the
stimulus of the bubbles of gas modifying the softness of the
alkali, rather pleasant than otherwise.

The appearances presented by re-agents are, —

With tincture of soap, a slight opalescence.

Nitrate of silver, an abundant precipitate, partially re-dis-
solved by pure nitric acid.

Sulphate of silver, a precipitate only partially soluble in
nitric or acetic acid.

Muriate of barytes, a slight precipitate.

Lime-water, a precipitate soluble with effervescence in acetic
acid.

Oxalate of ammonia, no precipitate.

On boiling, a slight pellicle appeared, soluble in nitric acid.

Carbonate of ammonia, no precipitate, nor any on the sub-
sequent addition of phosphate of soda.

The water restored the colour of Ktmus paper slightly
reddened.

With tincture of galls and ferrocyanate of potash, no change.

With muriate of lime, the water remained unchanged until
heated ; but when boiled, a copious precipitate took place.

When concentrated by boiling, the water reddened turmeric
paper, and effervesced strongly on the addition of an acid.

Nitromuriate of platina produced no precipitate, however
concentrated the water might be.

at Stanley, near Wakefield. W

The results of the previous experiments indicate the pre-
sence of

Soda, Lime in small proportion,

Muriatic acid. No magnesia,

Sulphuric acid, No iron.

Carbonic acid. No potash.

A. To ascertain the proportion of sulphuric acid, sixteen
ounces by measure, previously saturated by acetic acid, were
treated with muriate of barytes ; the precipitate, washed and
dried, weighed one grain ; this indicates, in the imperial gallon,
3.2 grains of sulphuric acid, equivalent to 5.8 sulphate of soda,
dry, or 13 grains crystalHzed.

B. For the muriatic acid ; nitrate of silver, added to six-
teen ounces of the water boiled, and the alkali previously satu-
rated, gave a precipitate weighing 2.8 grains ; reduced to the
proportion in the imperial gallon, this amounts to 26.9 grains
chloride of silver, equivalent to 11 grains chloride of sodium
(muriate of soda. )

C. The crystalline pellicle separated from a pint of sixteen
ounces, on boiling, weighed 0.2 grains.

This was carbonate of lime ; but in the water the lime would
be combined with muriatic acid, forming 0.22 ; or, in the impe-
rial gallon, 2.1 dry chloride, or 3.75 crystallized muriate of
hme.

D. The precipitate formed on boiling with muriate of lime,
weighed from the pint, 3.6 grains ; from the imperial gallon, 34.6
grains ; showing the water to contain in that quantity a car-
bonated alkali equivalent to 53 grains of dry, or 59.5 crystal-
lized bi-carbonate of soda.

E. Muriate of barytes, added to the water left on evapo-
rating sixteen ounces to two, gave a precipitate weighing 8.2
grains ; deducting one grain for sulphate of barytes, as found
in experiment A, we have 7.2 carbonate of barytes ; this indi-
cates in the gallon 53 grains of dry, and 59.5 of crystallized
carbonate of soda, as in the last experiment.

Lastly, a pint of sixteen ounces of the water, evaporated to
dryness, furnished in three trials of saline residuum, weighed
after short exposure to a. dull red heat, six grains, or 57.6 from

the im

perial gallon,

sist of

5,

.8

11.

1

^9

18

/7

38

.9

24; Mr. West on a 7iewly -discovered Spring

Now we have seen that this would con-
Dry sulphate of soda (exp. A).
Chloride of sodium ( — B).
Carbonate of lime ( — C).

57.6

The remainder, 38.9, having been converted by the heat into
proto-carbonate of soda, is equivalent to 54.5 dry, 61 grains
crystallized bi-carbonate, agreeing nearly with the quantities
found from experiments D and E.

Following, as 1 do, that doctrine which supposes the bases
to be distributed among the acids in a mineral water in the
combinations which possess the greatest solubility, we must
suppose the lime to be in the state of muriate ; we shall then
have to diminish the muriate, and increase the carbonate of
soda: so that on this view, the saline constituents of an imperial
gallon, in the state in which they exist in the water, are, —

Soda in combination with carbonic acid, equivalent to

Bi-carbonate or super-car--^

bonate of soda /^^ S^' ^^' ^^'^ crystallized

Sulphate of soda . 5.8 ditto 13 ditto

Muriate of soda (chloride 1 ^ ^^ ,. ^ „^

f. ,. X ^ I 8.75 ditto 8.75 ditto

or sodium) . j

Muriate of hme . , 2.1 ditto 3.75 ditto

The gaseous contents of the water consist of variable pro-
portions of carbonic acid^ sulphuretted hydrogen, and carburet-
ted hydrogen ; the latter gas is continually emitted from the
spring, in greater quantity than the water can absorb ; and a
portion of the other two also escapes from its surface. I have
made many experiments on the gas, separated by boiling; but
find the results, as I might anticipate, altogether inconclusive
and uncertain. In waters containing, as at Harrogate, these
gases with muriates or sulphates, boiling may be expected
almost wholly to disengage them ; but in this case the affinity
of the soda in dilute solution, is likely to retain the carbonic

at Stanley, near Wakefield, * 28K

acid, and even to cause a decomposition of the sulphuretted
hydrogen, so as to prevent our obtaining, in a gaseous form, the
quantity really existing in the water, and imparting to it sen-
sible or medicinal properties.

On the subject of medicinal qualities I am at all times
cautious of giving an opinion : but I may observe, first, that as
this spring is dissimilar to any of those which have already at-
tained celebrity, so none of them can form a substitute for
this ; it is not Harrogate, or Cheltenham, or Buxton, or Tun-
bridge water : the alkaline springs of the West Riding, of which
this is by far the strongest, stand as medicinal waters hitherto
alone ; the active ingredient, the bi-carbonate of soda, being
spoken of in chemical works, as ** rarely found in mineral
waters."

Secondly, from the known properties of this substance, car-
bonate of soda, and the frequency of its administration in a
long train of arthritic, calculous and dyspeptic complaints, the
water must be highly useful as an anti-acid and as a diuretic ;
and as the advantages which native mineral waters possess
over artificial solutions of the substances, in the great degree
of dilution, and the impregnation with gases, and still mor^ in
the adjuncts of leisure, exercise, pure air, regulated diet and
early rising, are of especial consequence in the latter very nu-
merous class of diseases, those called stomach and nervous
complaints ; we may fairly suppose that such a spring will be
found to be a valuable addition to those previously known,
applying, as it does, to cases of such frequent occurrence.

Observations on the State of Naval Construction in this

Country.

It appears that there is at present a tendency to improvement
in every branch of science ; monopoly in intellect may now
be said to be vanishing ; and empiricism is obliged to seek dark
corners, to escape the light which is penetrating into regions
from which it had but very lately been excluded. The admi-
nistration, too, encourages advance of knowledge ; yet notwith-
standing these favourable circumstances, there still exists, in

26 Observations on the State of

some minds, an inaptitude of scientific perception, which induces
unwiUingness to acknowledge the advantage that results from
the application of the exact sciences to the useful arts.

This neglect of scientific principles is nowhere more manifest
than in the affairs of naval architecture, and it is not confined
to the Royal Navy, but extends also to our mercantile shipping ;
and hence it is that our commercial marine is in some respects
behind foreign nations, especially the Americans, in the forma-
tion of its ships : our merchantmen are, almost without excep-
tion, the most unsafe* and slowest ships in the world. The
ship-owners, therefore, would do well to consider this circum-
stance, and endeavour to devise means of introducing science
into the merchant yards. The establishment of the new
university in the metropolis affords an opportunity of doing
it at a comparatively small expense, by the foundation of
Lectures on the theory of Naval Architecture ; and the
support even of a separate institution in the vicinity of the
merchant yards of this great port, for the education of ship
surveyors, would soon be repaid by the improved character of
our merchant shipping.

If the science of Naval Architecture depend on certain
physico-mathematical laws, as no doubt it does, it is monstrous
to imagine for a moment that such laws can be developed by
a flight of fancy, or that a man is born with unintuitive optical
perception of the lines of least resistance, &c., or, in the jargon
of the craniologists, that he has a naval-architectural bump on
his skull ; yet one would think that such was the case, when
we see men, we cannot say philosophers, start up and loudly
assert that they are in possession of the secret of construction ;
and they are believed because their hypotheses are never sub-
mitted to the examination of those who are capable of detecting
their fallacy.

The Experimental Squadrons have, with a multitude of per-
plexing results, elicited, it must be confessed, at least an
interesting fact, viz. that there has been an establishment
seventeen years in this country, in Portsmouth dockyard, for
the scientific education of naval architects, for the Royal

■ * By referring to Lloyd's List, it will appear, upon a moderate average,
that three English merchant vessels are lost every two days ?

Naval Construction in this Country, if§^

Navy.* From the plan of education, as laid down by the
Commissioners of Naval Revision in 1810, it appears that, to a
requisite knowledge of the practice of their profession, the
gentlemen composing this body of naval constructors unite a
sound and competent one of its theory^.

It can only be from such a source that we can look for the
improvement of our men of war, and it is to be regretted that
every means should not be taken to avail ourselves of it : but
unhappily such is the force of prejudice that, unless some alter-
ation should be adopted in this institution, it will be in vain to
expect advantage from it.

The objection urged against this establishment, namely, that
the scientific education it gives to its members precludes them
from the attainment of a due knowledge of the practical con-
struction of our ships, is so absurd, that none but weak or
jealous minds could ever have brought it forward. Shall it be
laid down, in the present age, as an axiom, that a profound
ignorance of the principles of his art is the one thing essential
to the formation of what is generally meant by the term '* prac-
tical man ?" We contend that, having made, in vain,^ a long
and most indulgent trial of a system without science, if we may
use such an expression, we must extend to one in alliance with
it, a like patronage, before we can be allowed to pronounce a
fair and legitimate judgment upon its efficiency.

But even in the peculiar path in which the naval architects
educated at Portsmouth might be supposed to excel, we do not
find that any opportunity is allowed them to come forward, nor
shall we see this until some effort is made by the heads of our
naval departments, to allow a broad and open competition to
take place. It may be urged, that the learned Professor at
Portsmouth (Dr. Inman) in himself includes all that can have

* See No. 11. of the Naval and Military Magazine, published in June
last.

t This will be readily acknowledged by those who will choose to read
the " Papers on Naval Architecture," and the *' Essays and Gleanings
on Naval Architecture," two periodical works proceeding from the mem-
bers of this institution.

% See the Third Report of the Commissioners of Naval Revision, and
the Resolutions of the Society for tlie Improvement of Naval Architec-
ture, in which the old system of providino; ship-builders for the Royal
Navy i| condemned in the most unqualified terms.

28 Observations on the State of

possibly been taught or understood in the establishment over
which he presides, and that therefore he is the representative
of it in the late and present trials for the palm of excellence ;
but we cannot by any means assent to this : many of the
students must have left his tuition seven, eight, and nine years,
and must be between thirty and forty years of age ; and it
would be strange indeed, if during such ^ period, and in the
prime of life and intellect, some of these, if not all, had not
cultivated the science after their own bent of mind, and formed
original ideas on the subject : we say, therefore, that Dr.
Inman's constructions cannot be called the production of the
establishment — they are merely the effort of one man, whose
attention it appears is distracted by a multiplicity of occupations,
and can only, along with the vessels of Capts. Symonds, Hayes,
and Sir R. Seppings, be deemed criterions of the particular
views of an individual.

Mysticism and ignorance always accompany each other ;
and we may reckon that in proportion as the latter disap-
pears from amongst our ship-builders, so will the absurd
vagaries of the former recede, and the subject be placed
at last on the true principles of philosophical induction,
instead of the caprices of imagination. We look forward,
therefore, to this new body of naval architects for the expulsion
of all quackery from their profession, and for the exposition
not only of what we really do know, but also of what we do not
know about it : this is the only way to arrive at truth, which
should be the sole object of all investigation ; but which we
are afraid has hitherto been sadly garbled and perverted
wherever it has had to do with naval architecture in this
country.

But we repeat that we do not see that the nation is at all
likely to benefit from the science or exertions of those gentle-
men so long as they are placed in situations where a superior
education can have no other effect than producing disgust and
chagrin in the mind of the possessor ; and if the institution at
Portsmouth be designed for no better purpose than that of
supplying house-carpenters, joiners, and still more inferior
trades, with foremen, it had better be abolished. Some would
regard it, as at present used, as a gross mockery on the public

Naval Construction in this Country, 29

at whose expense it is supported ; it is certainly a cruel one
of those who have been induced, by the fair and brilliant pros-
pects held out to them of support and encouragement, to devote
their lives to this branch of the public service.

But to return to the Experimental Squadron : it is with regret
that we must conclude, upon a careful consideration, that,
although the experiments are carried on with so much vigour
and interest, they are evidently founded on imaginative views,
and that there cannot exist any thing like legitimate data where
so many failures and anomalous results obtain. Who can read
the account of the first Experimental Squadron^*, without im-
mediately perceiving that the constructors of the contending
vessels, however sanguine each might have been of the success
of his particular fancy, met with nothing but the most perplex-
ing results ? We see sometimes one and sometimes the other
vessel claim the palm of excellence, and finally leaving the sub-
ject as much in the dark as ever. This is the natural conse-
quence of the non-application of inductive philosophy to the
question before us, and the most important conclusion that can
be gathered from the experiment is, that we have begun at the
wrong end, and that it is high time to employ analysis instead
of synthesis to effect the desired objects : for in the present
state of the theory of naval construction in this country, there
are yet no data existing to effect with precision and confidence
the synthetical composition of a ship.

We cannot refrain here from noticing the paucity of informa-
tion contained in the reports hitherto made on the first Experi-
mental Squadron. The best one* is but little removed from a
ship's log book, and in some respects is inferior to it : it is of
such a scanty nature, that we can scarcely inform ourselves on
any point, and that only in a relative degree, of the qualities of
the vessels composing it : we cannot find out any mention of
their absolute velocities on the different points of sailing, which
is a most important omission. We are neither informed in what
way the observations were conducted, whether they were made
simultaneously or not : unless the former, any attempt at com-
parison must be very doubtful, if not entirely fallacious. Cir-
cumstances of wind and weather may very widely alter in the

♦ Vide No. 1 of the Papers on Naval Architecture.

30 Observations on the State of

course of a short time, and every endeavour at legitimate ana-
logy be destroyed by such variation. We strongly suspect that
this is one cause of perplexity ; and another prolific one is the
vague idea given of the strength of winds by nautical language.
Nothing but the determinations of the anemometer should ever
be allowed to appear in an account of such experiments. Every
circumstance attendant on the quantity and trim of sail, the
heeling, the rolling and pitching of the ship, position of the
rudder, &c. should be accurately ascertained and tabulated ;
for it is next to an impossibility and a wilful waste of time to
attempt to institute comparisons without pursuing a system of
tabulated results, which should be kept in the same form on
board each ship.

We must also express our regret that the scientific professor
at Portsmouth does not appear to have ascertained the position
of the centre of gravity of any of his ships, with regard to
height, by the simple and easy experiment long known in prin-
ciple, and described lately with geometrical rigidity in two or
three publications by some of his pupils*. The knowledge of
the position of this point would have placed him so far above
his competitors, in so many important particulars, that we are
surprised he should have thrown away his advantage, and de-
scended to a level with his less scientific opponents. We are
afraid that, here again, imaginative views have stepped in, and
taken the sober mathematician from the only path by which
excellence can be attained. We are at a loss to conceive how
the stabilities of his ships can be said to be ascertained without
the knowledge of the position of this point.

Some of the obscurity which pervades this difficult subject
may be overcome, as to broad and general principles, by atten-
tively and coolly observing the progress of marine architecture,
since the introduction of cannon into naval warfare, and more
particularly during the last century and a half We shall then
clearly perceive that the French, who, as early as the beginning
of the reign of Louis XIV., employed men of first-rate talent
in their naval arsenals, and neglected no opportunity for the

* Vide Annals of Philosophy, for November, 1826 ; No. 1 of the
Papers on Naval Architecture, and No. 11 of the Essays and Glean-
ings on Naval Architecture.

Natal Construction in this Country^ .'^

advancement of science in them, increased and kept increasing
the dimensions of their ships, more especially the length, thie
ratio of which to the breadth has been augmented by them from
about 3:^.1, to 4.1 within the last century. While this princi-
ple was acted on, the improvement of their ships was gradual ;
and by referring to our own progress in the art, in tardy imita-
tion of the practice of the French, we shall likewise conclude
that our navy has derived precisely similar advantages from the
same causes. Here we have at once two grand but concurring re-
sults derived from an experiment, not made on one or half a dozen
different vessels, but on the whole navies of the two most pow-
erful maritime states in the world : and if to these we choose to
add the result of the practice of the same means on the Spa-
nish and other navies, we might surely be warranted in saying,
from this broad but certain analysis of facts, that, in relation
to the hull, the general increase of dimensions, with a greater
relative length, is one cause of the improvements that have
been made in the sea-going qualities of the ships composing
the fleets of the present maritime powers : the question there-
fore that remains to be decided on in relation to this principle
is, whether we have arrived at its utmost practicable limits, or
rather, whether we have arrived at the maximum of improve-
ment it is capable of producing.

This brings us again to the experimental squadrons, as far as
they are connected with, and illustrative of, our observations ;
and the first question naturally put forward about them is,
whether there be any thing very peculiar in the formation or
dimensions of the rival vessels ? We suspect that the answer
cannot otherwise than disclose, that neither in principle, dimen-
sions, nor in the formation, can they be said to differ very ma-
terially from each other, or from ships of the common construc-
tion : indeed we perceive in some a retrogression of ideas and
a violation of the principle, that the increase of the ratio of the
length to the breadth, in conjunction with a general increase of
dimensions, has been a predominant cause of improvement.
The fact also of so immaterial a difference necessarily includes
a system of masting and sails equally confined, and totally ina-
dequate to produce any great superiority of sailing over ships
to which they are so nearly equal in principal dimensions.

32 . Observations on the State of

' After so many years of trial with the present nearly invaria-
ble set of principal dimensions, during which period it may be
said, that every possible contour of hull has been experimented
on with them, we are inclined to think that almost all has been
done that could be done under such restrictions, and that some
great step must be made in one or other of the principal dimen-
sions themselves, with correspondent alterations in the masting,
before Ave can expect to see a decided and great improvement
in the sailing of our ships. The depth is an element which has
arrived at its limit from very apparent external causes ; but the
length and breadth remain to the skilful constructor without any
such clogs to his endeavours; and he has only to accommodate
their relation to each other in the manner most conducive to ve-
locity, which in our opinion is the very capital object of naval
construction, both in ships of war and of commerce. That it is so
in the former, no one will, we apprehend, on due reflection deny ;
but there will be many who will assert that it cannot be ob-
tained, in the latter, without a sacrifice of capacity, which will
defeat the object of carrying large cargoes : to this we may
reply, that if a vessel with an expense of one quarter the capa-
city can make three voyages instead of two, will not the mer-
chant be still a considerable gainer in capacity, and still more
so by a ready return of his capital* ?

AH observations on well-conducted experiments concur in
proving that velocity is gained by increasing the length, to a
much greater degree in relation to the breadth, than has ever yet
been done in ships ; and that the increase of the same element
contributes to their weathering powers is too obvious to need in-
sisting upon : it is also generally advantageous, when not carried
to an extent which would seriously retard the manoeuvring of the
ship. This limit has not yet by any means been determined ;
for it must be recollected, that although the additional length
increases the resistance to rotation about a vertical axis, yet
the power of the sails to give rotation about the same is also
increased, although not in so high a ratio. The power of the
rudder to produce rotation is also greater in a long ship than in

* Foreign nations, and more particularly the Americans, find their
advantage in having swiil merchant ships, and therefore our assertion is
warranted by facts.

Naval Construction in this Country. 33

a short one, not only on ax:count of the greater distance it Is from
the axis of rotation, but also on account of the greater velocity,
and the more direct impulse of the water on it.

The increase of the ratio of the length to the breadth to pro-
duce velocity should not interfere with the increase of breadth
necessary to produce stability or capacity ; for both these qua-
lities, varying as higher powers of the breadth, a very small in-
crease of breadth may be attended with a considerable increase
of length. If we compare the Caledonia's (120 guns) dimen-
sions with those of the Royal George and Queen Charlotte*,
of 1788 and 1789, we shall find, that 13 or 14 times as much
length as breadth has been added to the first rates of our navy.
If we refer to the dimensions of the Commerce de Marseilles,
and those of the next preceding three-decker of the French
navy (for instance, the Ville de Parisf , taken in Lord Rodney's
action), we shall find that the French naval architects gave in
her 21 times as much increase to the length as to the breadth.
If this could be done with safety in a three-decked ship, with
such a vast top weight, much more could it be carried advan-
tageously into effect in ships of two decks, and frigates ; but we do
not find, in the latter classes of the ships of the French navy, the
increase of length to go beyond six times that of the breadth.
If we refer to the Old Bellerophon, built in 1772, and the New
Bellerophon, built in 1819, we shall find an increase of 24 feet
in length, to 1.58 feet increase of breadth ; or the former more
than 15 times the latter J.

To those who oppose the objection that a greater length than
at present used would make the manoeuvring of a ship too
slow, we answer, that as the Caledonia and the present first
rates of our navy, although from 10 to 15 feet longer than
our two-deckers, are found to be capital ships in this respect,
there is a sure ground to believe, that the addition of 20 feet in
length to the present two-deckers would not render their cele-

* Caledonia, lens^th 205 feet, breadth 53.5 ; Royal George, len^h 187
feet, breadth 52.33 feet ; Queen Charlotte, length 190 feet, breadth 52.33
feet.

t Ville de Paris, length 185.62 feet ; breadth 52.7 feet ; Commerce de
Marseilles, length 208.33 feet, breadth 54.79 feet.

% Old Bellerophon, length 168 feet, breadth 47.33 feet; New Bellero-
phon, length 192 feet, breadth 49 feet.

JULY — OCT. 1827. D

Si Observations on the State of

rity of evolution less than that of the three-decker ; and since,
from the reduction of weight aloft, the centre of gravity would
be lowered, and the displacement required to be less, a some-
what smaller breadth might be allowed to a two-decked ship of
206 feet long, than to one of 196 feet (especially since the
quantity of sail, remaining the same, is lowered by one whole
depth between deck), a smaller midship section would be, ccsteris
paribus f required ; the velocity of this ship might be consider-
ably increased. Nothing however can be precisely determined
on, with such a complication of circumstances, beyond a general
idea. Calculation and a strict analysis of ships must be re-
sorted to, in order to fill up the outline of our reasoning.

But for the same reason that we imagine that an addition of
20 or perhaps 40 feet would not sensibly injure the celerity of
manoeuvring of our two-deckers, we should think that the same
increase of this dimension might be tried without much risk to
our first rates, with an increase of breadth not exceeding -gi^th
part that is given to the length.

We repeat that the very capital object of the science of
Naval Construction is velocity ^ and we are decidedly of opinion
that it is attainable in a much higher degree than at present,
without compromising other necessary qualities, for which we
have the concurrence of facts as far as they gd.

* The Anglo-Americans, in the last war, took every possible
advantage suggested by views similar to those we have been
adverting to, in the construction of their large frigates. They
had, it may be said, to create a martial navy, and they had to
oppose it against fearful odds ; but, free from the prejudices
and errors so blindly cherished by their opponents, and which
constantly oppose reform by always declaring the present prac-
tice to be the best, they did not retread the old path, but began
at its last step, and boldly advanced on this principle into all
the branches of the art. They built vessels upon the most en-
larged dimensions, and of a superior weight of metal, and gave
an increased ratio of length to the breadth. The result of such
a procedure, justified the confidence of the American naval
architects in only one maxim, founded upon the scientific ob-
servation of facts, and may give us a faint idea of what might
be effected by a still more enlarged and mathematical analysis.

Naval Construction in this Country. wo

Our frigates were so inferior to theirs in every way, that they
brought nothing but disasters iipon us, excepting in the action
between the Shannon and Chesapeake, and one or two others,
where, assured by their previous successes, our gallant oppo-
nents threw awiy the advantages possessed by their ships, by
coming to close quarters at once, and deciding the contest hand
to hand. — Our ships of the line could never bring these frigates
to action, and owing alone to their extraordinary sailing, did
they evade and mock a large British fleet. We were finally
obliged to build 60-gun frigates after their method, but when
it was too late for the exigency of the period ; and thus it has
ever been our fate, for want of science in the constructors of
our navy, to follow the steps of our enemies at a humble dis-
tance, and to be only then driven out of the old track by a
terrible experience of its inefficiency.

Nor have the Americans stopped here ; — Mr. Huskisson
plainly tells us that "America is, year after year, augmenting
its military marine, by building ships of war *of the largest
class*." According to Capt. Brent on, they have built a first-
rate f of 245 feet length on the gun deck, and 56 feet broad J,
to carry 42-pounders on the lower deck, and 32-pounders on
the other decks.

Our small class of 74-gun ships lately converted into frigates
carrying fifty 32-pounder guns, we are fearful can only produce
disappointment if ever brought against the American frigates
(not byconversion, but by construction), which carry sixty-two
guns of the same calibre, and are 180 feet long oil the gun
deck.

We must not forget also that our active neighbours the
French have now adopted a most formidable description of

* Vide this gentleman's speech on the Shipping Interests in the
House of Commons, May 1827.

t Called by Capt. Brent on the Ohio ; but it appears from Lieut. De
Roos' personal narrative, just published, that the Ohio is a two-decker
of 102 guns. It is to be supposed, therefore, that the three-decker of 135
ffuns, called the Pennsylvania by the latter, is the ship alluded to by the
former. It is a matter of gieat regret that Lieut, de Roos has not pre-
sented us with the precise dimensions of these ships.

X These dimensions carry tlie ratio of the length to breadth above
4i to I.

D2

36 Observations on the State of

frigates, with curvilinear sterns*, and many other important
improvements. They mount 60 guns and carronades — viz. 24-
pounders on the gun deck, and 36-pounder carronades on the
flush deck. — The former caUbre is equivalent very nearly to
26, and the latter to 391bs. avoirdupois. i>

When we reflect on these circumstances, we cannot but feel
surprised that so many frigates of inferior force and dimensions
should be building in our dockyards. In time of emergency
they will only bring on us a repetition of former disasters and
deficiency. We contend that, instead of building ships of only
equal force to those of our rivals, and thus waiting for the
developement of their designs before we can venture on a single
step, we should build beyond them in every respect. It must
and ought to be recollected, that peace in these matters pro-
duces a contest of intellect, and those will have the advantage
in it who attack instead of standing on the defensive. We
ought to lead the way, and to be at the head of the maritime
world, not in number alone, but also in the individual force
and qualities of our ships.

Having expatiated on the advantages of an increased ratio
of length to breadth in relation to the hull of a ship, we will
just glance at some of the principal effects it would have upon
the masting and sails ; and here again we conceive that Pro-
fessor Inman has, in common with many others, relinquished
the many good effects resulting from it, for the inadequate one,
of being able to carry a somewhat greater quantity of sail,
which must necessarily be lofty, and which, (setting aside this
detracting circumstance,) as the velocity of a ship varies only
as 2i fractional power of the surface of canvas spread, cannot
produce the degree of fast sailing to be wished for, but at an
immense and impracticable quantity of sailf.

A greater proof of the inadequacy of the present system of

* The French Admiral Willaumez, in his " Dictionnaire de Marine,"
published in 1 820, says under the article Fregate, that as far back as
1804, he had proposed a plan for a frigate of the largest size, with a
round stem, wherein the quarter galleries were suppressed : the first
frigate upon his plan was built at Brest about 1821 .

t As the square root, so that to get twice the velocity, /owr times as
much canvas must be spread ; and this is the most favourable estimate
that can be made.

Naval Construction in this Country, '^

lofty sail cannot be cited than the fact of its not procuring,
under the most favourable circumstances, a rate of sailing
rarely exceeding one-fourth the velocity of the wind.

As the number of masts should be so regulated as to create
facility in managing the canvas, which is well known to be at
present hardly manageable in a gale of wind, on board large
ships, from the enormous size of each individual course and
topsail, we should not hesitate, therefore, to have four ver-
tical masts, as recommended by Bouguer, instead of three, in
ships built in accordance with the principles we have been dis-
cussing. This would, cceteris paribus, require shorter masting
and smaller yards, and the sails being much less, individually,
would be more easily managed and not so liable to accidents.

From what has been said, and the actual experiments now
pending, it is apparent that the theoretic construction of ships
is at a very low ebb in this country; yet a fine opportunity now
presents itself, if we choose to avail ourselves of it, for rescu-
ing the nation from this generally acknowledged odium. Let
a proper use be made of the corps of Naval Architects we
have, somehow or other, at last got, and let their exertions, under
a degree of encouragement equal to that bestowed on the old
ship-builders in vain for so long a period, be directed towards
the improvement of their art. If they fail, they cannot claim
the excuse of having their endeavours repressed ; if they suc-
ceed, as no doubt they will, in advancing their profession to
something beyond mere carpentry, we shall be enabled to bid
adieu to the old and ruinous method of blundering, under the
reign of which nothing but disappointment can ever be reason-
ably expected.

We have seen and do still see the immense advantages de-
rived by our country from the encouragement of those branches
of science connected with its manufactures and agriculture ;
and if we wish to keep our present superiority, we must follow
up vigorously this principle in all its universality. To the cavils
of ignorance and bigotry against such a mode of proceeding
we would answer, in the words of one of the most enlightened
members of the present administration, " This country can-
not stand still, whilst others are advancing in science, in in-

86 Observations on Naval Construction.

dustry, in every thing which contributes to increase the power
of empires, and to multiply the means of comfort and enjoy-
ment to civilized man."*

It is to be hoped, therefore, that His Royal Highness the
Lord High Admiral will extend to this most important national
institution, the School of Naval Architecture, the same vigilant
and scrutinizing eye that every other branch of our naval sys-
tem is at this moment experiencing from him, and that he will
extend to it that fair play and encouragement which has
hitherto been denied to it. As a seaman, he can fully appre^
ciate and understand how much the bad qualities of a ship
may neutralize the best exertions of the most experienced and
skilful sailor ; and, on the contrary, what a degree of confidence
may be insured in naval operations with excellent ships. We
feel persuaded, therefore, that he will not allow others to think
for him in a matter of so much national importance, and thus
allow private ends to interpose to the disadvantage of public
views ; but that he will investigate and judge for himself. We
would humbly suggest to His Royal Highness to inquire into the
individual acquirements and productions, both of a theoretical
and practical nature, of those who have been educated in this
establishment, and he would soon be able to decide whether
they be fitting or not for the important task of constructing
our ships, and for the confidence and protection which we
think we have shown has hitherto been ill-advisedly withheld
from them. Such a line of conduct would very soon carry
our naval architecture to a pitch of excellence worthy of imita-
tion, and instead of being indebted to foreigners for models, we
should be able, with just pride, to point to the productions of
British science and intellect in this noble art.

* Vide Mr. Huskisson's speech on the Shipping Interests.

39

On Malaria, No. II.

[Communicated by J. Mac CuUoch^ M.D., F. R.S.^ &c. &c.]

Having pointed out, in the former paper on this subject, the
nature of the soils or places, of whatever description, by -which
malaria is generated, it remains to notice a few other circum-
stances connected with its natural history, a knowledge of
which is essential for the purposes of prevention ; and finally to
describe such modes of prevention, applicable to these several
circumstances, as have been found useful in guarding against
the attack of diseases from this cause. Under the first head,
there remain to be considered, the effects of climate and season ;
the changes which occur in the production and propagation of
malaria, from various natural and artificial causes ; and also,
the various modes in which it is propagated.

It has already been remarked, that a certain elevation of
temperature was necessary to the production of this poison,
though what the precise degree is, has not been ascertained;
and as this is, chiefly, what distinguishes the regions or periods
of the year which generate malaria, I need not make two divi-
sions of season and climate. If, however, this temperature is
not fixed, it will perhaps suffice for our present purposes to say
that the greater part of Scotland, whether as to climate or
season, seems incapable of generating the disease from this
cause ; though there are exceptions of a permanent nature, or
exceptions of climate, as was perennially true of the Carse of
Gowrie before its drainage ; while there are others which happen
when, as in the last year, there has been a pecuharly hot
summer, and which are exceptions of season.

And thus it is as to more northern regions; where a hot
summer becomes more than an equivalent for an average low
temperature ; as an example of which, there is no place where
intermittents are more severe and abundant than at Stockholm.
But the extreme of evil from this cause occurs, as is well
known, in the tropical climates; appearing almost proportioned
to the heat of the climate, and what is important to observe
to the moisture also. The destructive effects of certain parts of
Africa, India, America, and so forth, are famiharly known ; and

40 On Malaria.

it is in these countries especially, that the diseases from this
source constitute nearly the entire mortality of the human race.
And thus, for Europe, it is in Spain, Italy, and Greece, and
chiefly on their Mediterranean shores, that the activity of mal-
aria scarcely yields to that of the intertropical climates ; while
in France, Holland, Germany, Hungary, and with us, in a far
less degree, the production will be found regulated by the heat
of the summers, all other circumstances being the same.

And if we thus account for the variations in the quantity and
virulence of diseases in any given country, for noted seasons of
epidemic in the countries which I have just named, and for the
great prevalence of fevers among ourselves during the last few
years, and particularly in the last summer, there is another
point of scarcely inferior importance to be taken into the con-
sideration, independently of that which relates to peculiar
winds as connected with the propagation of this poison ; — and
this is, moisture.

I need not repeat that water in some form is necessary to
the production of that peculiar vegetable decomposition which
is the source of this poison ; and so true is this, that even in
the tropical regions, the diseases from this cause are nearly
miknown]in districts of peculiar dryness, as they are in the
drier seasons of those countries. Thus, for example, Egypt is
free from such fevers, except at the period of the subsidence of
the Nile, unless where, as at Damietta, the cultivation of rice
is pursued ; and the same is true of Mesopotamia very remark-
ably: and if I dare not extend these illustrations, I must
remark that in all these cases, the action of moisture is two-
fold, inasmuch as it not only accelerates vegetable decompo-
sition, but renders the atmosphere a fitter conductor of this
poison.

Taking these two causes of the increase in the quantity and
in the action of malaria, we can explain many particulars which
relate to its power in producing diseases ; and as the knowledge
of these is important as far as relates to the main object of this
paper, prevention, it becomes necessary to explain them at a
little more length.

As to season, the simplest case is that of the intertropical
climates; and Africa offers the plainest instance among the

On Malaria, 41

whole. There, the malaria and the fever commence at the
moment the rain falls; diminishing as the ground becomes
thoroughly wetted, and recommencing as it dries. The expla-
nation of all this ought to be obvious ; and the same analogy
governs all the hotter climates, as, though less conspicuously,
it does our own. Hence we explain, both as to our spring and
our autumn, the effects of heat following rain, or the reverse,
and the diseases which are consequent on those changes : and
thus it is, though more remarkably, in Italy, that a rainy
autumn increases the number and severity of fevers ; or, if the
summer has been unusually dry, that they often do not appear
till the commencement of the autumnal, or even the winter rains.
And hence, also, even with us, the occurrence of a single rainy
day or week, in the midst of the heats, will produce fevers ;
while the effect of this influence is such, that should there even
be an entire rainy summer, and the subsequent one be hot and
dry, this will be attended by an unusual production of malaria
and disease.

And if I cannot detail all the various modes in which
these circumstances may be modified, and how their effects
may vary, it will be useful to make one remark on an error as
relating to it which is universal among us, and into which even
Lind has fallen. The error is, to think that the rain, the moisture,
or the cold is itself the cause of the diseases which follow this
state of things ; while it is obviously a case analogous to that
of Africa, if less severe, and the malaria is produced by these
circumstances on soils which I formerly pointed out, and which
Lind, like every one else, had neglected. But if I must pass
over many interesting and useful conclusions to be drawn from
these general principles, there is one fact which I must notice,
and it is this : —

In spring, the combination of heat and moisture, easily ex-
plained, generates, most commonly, intermittents ; or the effect
of the malaria at this season differs from what it does in
autumn : while as the heat advances and the ground dries, this
kind of fever ceases to be produced, a new species, or the sum-
mer remittent, taking its place when the heat and the moisture
of autumn begin to act. But under peculiar seasons of heat
and moisture with us, it sometimes occurs, as it has doue

43 On Malaria,

within the last years, that the intermittent season runs into the
remittent one, or there is no midsummer interval of freedom
from disease ; while it has also happened, and in some parts of
England in this last year, that what would have been intermit-
tent fever in other years has been remittent ; or the common
fever has occupied the whole summer, continuously, even from
March to November, as is the case in the worst regions of
southern Europe.

Now, under these exceptions, which I was bound to explain,
the commencement of intermittent, or of vernal ague, may be
fixed about the middle or end of March, and its termination
similarly in May ; while that of remittent may be placed in the
beginning of August, and its termination with the middle or
end of October. How these periods may otherwise be affected
by the more or less insalubrious nature of the district or place,
will easily be judged of by those who will reflect for them-
selves on what I dare not explain, lest I should infringe too far
on my limits. All else that I can venture on, as to this part of
the question in hand, relates to the effects of the different
times of the day on the production, propagation, or influence
of malaria, and it is one which is of no small importance in a
practical view.

AVhether the changes as to temperature and moisture which
occur within the space of twenty-four hours, affect the produc-
tion or propagation of malaria^ I will not here inquire minutely,
from the fear of prolonging this very limited paper ; but the
general facts, as to its effects, are these : If we commence with
the sun on the meridian, there appears, even in the worst cli-
mates, very little hazard of fever ; while in Italy, it is believed that
there is, generally, little or no hazard, except in some peculiarly
pestilential places, and under particular kinds of inattention or
neglect. Either the malaria is decomposed or destroyed by
the heat, or else the air from its dryness ceases to be a con-
ductor; but as evening approaches, its influence becomes pow-
erful and dangerous, being supposed most generally to extend
all through the night; while in some parts of that country it is
a popular belief that it terminates before midnight, or with the
precipitation of the atmospheric moisture. Whether this last
opinion is true or not, the general fact explains the popular

On Malaria^, 48

belief, and truth, respecting the poisonous effects of dew in the
hot climates; the supposed pernicious quality of this depending
evidently on the malaria by which its formation is accompa-
nied. And in this case it is probable that the evil arises, not
from a fresh or peculiar generation of malaria, but from the
mere fact that the moist atmosphere is a better conductor than
a dry one.

Not to be unnecessarily minute, we thus also explain the
danger of exposure to the morning air in similar situations ;
the facts, as they relate to the conducting of malaria, being the
same, though the meteorological circumstances are somewhat
different. Hence, also, we see why the grey mists which hang
over wet grounds in the evening in our own climate, are
esteemed pernicious ; the truth, however, being, that they are
perfectly innocent at certain seasons and in certain places — as
in the greater part of Scotland, for example, or in those places
and at those periods where malaria is not produced. The dis-
tinction is valuable, because of the inconvenience of restric-
tions on this subject, and because to know where the hazard
really lies is to reduce those, and also to prevent the infraction
of rules by not extending them beyond what is necessary ; and
thus also by seeing what are the real dangers of what is called
night air, we more easily avoid them. Night air is avoided
now, under a false philosophy, because it is cold or damp, or
for some other vague reason; while the dangers from mere
dampness or cold are as nothing compared to those here pointed
out; which also occur precisely where they are least feared,
namely, in warm summer evenings, after refreshing showers,
and so forth. Hence it is that fevers are produced in summer,
in rural situations, and especially perhaps amid the most
engaging scenery, by evening walks and exposure to what is
naturally considered, as it is felt to be, a balmy and refreshing
sequel to a hot day. Let this be enjoyed where it can with
safety, and as it often may ; but such evening walks will not be
safe in any of those situations which I need not repeat here,
after having detailed them as I have done in the former paper.
And lest I should be accused of wishing to excite unnecessary
alarm, I consider, on the contrary, that it ought to be dimi-
nighed by these remarks ; because, if we taJie the whole of

■44 On Malaria.

England, there is perhaps not one acre in a hundred thousand
where there is danger from night air, or from malaria in any
mode ; so that to distinguish where that lies, is to have relieved
from useless fears all those who may learn to make the distinc-
tions under review.

To pass from what relates to climate and season, and to pro-
ceed to the propagation, simply, of malaria, it is almost super-
fluous to say, that its influence, as to the production of disease,
is much regulated by proximity, which implies a state of con-
centration or accumulation. Hence the danger arising from
vicinity; while, as I formerly remarked, where the generating
source is small, this becomes necessary to its effect, since dilu-
tion may be expected to destroy the power of the poison.

For analogous reasons, its effect in the production of disease
is increased by concentration or condensation ; and such a
state of things takes place in narrow and confined valleys, or
in places surrounded by woods, or in woods themselves; in
any situation, in short, where the poison is produced, and is
so sheltered from winds that ventilation becomes difficult. And
if it is probable that this is one chief reason of the peculiarly
insalubrious nature of woods and jungles in hot climates, so is
it an universal remark in Italy, that the short valleys in which
the air cannot circulate are among the most pestilential spots.
And if this explains, also, in some measure, the bad effects of
calm weather, so does it account for the unusually pestiferous
nature of rivers and lakes confined within wood, as are those
of the tropical climates, and as there are many also in different
parts of Europe. That we ourselves are not exempt from
these additional causes of the influence of malaria, would be
easily shown by many references, were it not for the reason
which has caused me to exclude them.

It is another important question for practice, how far and in
what manner malaria can be conveyed by the winds to places
where it is not produced, so as to act in exciting disease.
That it is conveyed to certain distances by winds is amply
proved by an abundant experience, and I may first detail a
few of the most useful particulars as to this fact. In Italy and
Greece, it is obser\^ed, that where long valleys terminate on sea
shores, on which the exits of the rivers are swampy, it is an

On Malaria, 45

effect of the sea breeze, by crossing such marshy ground, to
convey the malaria up into the interior country, to considerable
distances, and to places which are in themselves not insalu-
brious. Thus, also, does such a breeze, especially when it is a
warm wind, convey the poison up the acclivities of hills, even
to a considerable range of distance or elevation; a process
facilitated by the natural tendency of such winds to ascend.
And as a striking proof of this migration of malaria, it appears
from Capt. Smyth's statistical account of the insalubrious vil-
lages in Sicily, that out of more than seventy, about one-half
are not seated near or on lands producing this substance, but
on acclivities, at varying distances — thus receiving it through
migration. The same is remarked by Montfalcon of many
towns in France ; while in some, the place at a distance is even
more unhealthy than that which is immediately situated in the
marsh itself: and in our own country, this is equally said to be
true of the backwater at Weymouth, and of the marshes of St.
Blasey in Cornwall, acting more powerfully at some distance
than in the immediate spot.

With respect to the absolute distance to which the malaria
can be conveyed, it is yet an obscure circumstance, or at least
the maximum has not been fixed ; but it is at least ascertained
that the convent of Camaldoli receives it from the Lake
Agnano, at a distance of three miles; while from certain
naval reports, a distance of five miles has been proved to
permit its transmission, — and from an evidence that cannot be
doubted, inasmuch as it was the sudden breaking out of fever
in a healthy ship, anchored at that distance from the shore, on
the coming off of the land wind, attended by its peculiar and
well-known smell.

These facts are satisfactory thus far, and it would be abund-
antly easy to add to them; but there is reason to suspect that
it can be conveyed to far greater distances, in certain favour-
able circumstances: those reasons, in the first place, being
derived from certain meteorological analogies and considera-
tions, and in the next confirmed by experience. It is notorious
that the ague appears on our eastern coasts with the first east
winds of spring ; and while this circumstance is most common
on those of England, as for example, in Kent, Essex, Norfolk,

4S On Malaria.

Suffolk, and Lincolnshire, it is not thus hmited, since it is
known to happen further north, and even in Scotland, where
malaria is not indigenous to the soil. It is very true that if we
take any inland position in the places thus noted, the natural
solution is, that the malaria is generated in the very soil itself
of England, and merely propagated, perhaps even to very
moderate distances, through those winds. But the occurrence
of disease cannot be explained thus, when the place in ques-
tion is so situated that there is no land to the eastward, or
when the breeze is, most literally and rigidly, a sea breeze ;
while, when ague thus occurs on the east coast of Scotland,
where it is not produced by the soil, it must be imported by
the east wind.

. These are the facts; while as malaria is not produced by the
6ea itself in any known circumstance, though a vegetating sea
beach may give rise to it, we must seek the cause in lands far
distant, and consider this as a case of propagation of the
poison from the shores of Holland ; and those shores are un-
questionably competent to that effect : so that the only question
that remains, the fact being admitted, is, whether, a priori, or
theoretically, such a view is probable, or whether it is con-
sistent with those physical principles that are concerned in the
propagation of malaria.

I am aware that such a view will excite the incredulity of
those who have not attended to this subject ; though it appears
to me that it comprises nothing averse to our knowledge of the
philosophical circumstances concerned. In the first place, let
us remark that the east wind, and particularly the east winds
gf spring, are notorious for their moisture, and that a moist air
is the best conductor of malaria, as moisture in the air, under
the form of evening mists, or in other modes, appears even to
be its proper vehicle, or residence, if I may use such a term;
and though I have not as yet separated the case of a fog, I
may now remark, that the effect in question, or the production
of agues by fogs arriving from the sea, is e\en more notorious
than their generation by an ordinary clear wind. So notorious
and popular, indeed, is this fact, that the fog itself is deemed
the source of the disease, as the east wind under any form is,
in other circumstances ; while I hope it will even now appear,

On Malaria. 47

that the real cause lies in the malaria transported or conveyed
by those winds or fogs, and of which they are the true and
best repository and vehicle.

And these are the reasons for thinking that the malaria, with
the wind, may be transported to a distance as great as that
which the present view requires ; most easily perhaps in a fog,
but without difficulty even in a clear wind. It is remarkable
that the east wind, as it is the most persevering, is that one
also which preserves the most steady horizontal and linear
course. J have also shown, in a former work, that it is a pro-
perty of winds to travel in distinct lines through a tranquil
atmosphere, and often in streams of a very limited breadth ; that
opposing streams will also move, in absolute contact ; and that
even rapid streams of wind will cross each other's courses with-
out difficulty. This proves that, in any such stream, there is
a principle of self-preservation or integrity, and renders it pro-
bable that the several portions retain the same relative places
to each other, at any distance, during the career of the whole :
and there is a proof of this afforded in the fact of those
columns or streams of insects which are brought over by such
winds, and very frequently from those very countries, or from
Holland and Flanders, in the most regular order, or without
disturbance or dispersion.

Hence it may be argued, that if a malaria, generated any
where and conveyed by the winds, can be transported to a dis-
tance of three miles, as has been proved, there is no reason
why it should not travel much farther, or to any distance that
can be assumed : and if this be true of a clear wind, the case
of a fog is even a much stronger one; since there is little
reason to doubt that the individual parts of such fog, in any
assumed mass, will retain their relative places to each other, as
perfectly after a journey of any given number of miles, as they
did at the point of production ; and if a portion of malaria has
been united to a portion of fog, in the marsh which produced
both, or whence both have come, there is every apparent
reason why it should be found in that same portion at any
farther or assumed distance, because there is no cause for
either its dispersion or its decomposition.
• A fog is a cbud, simply ; and it is notorious that a single

4^ On Malaria*

cloud, and often of very small dimensions, will remain at rest
in the atmosphere, or travel very many miles without the loss
of its integrity; however we may imagine it assailed by the
various meteorological causes of destruction, as well as by me-
chanical violence. This in itself proves the consistency with
which a current of wind preserves the relative positions of its
integral parts; because it is plain that a disturbance among
these must disturb or destroy the cloud which, in reality, forms
a portion of that current, as a gaseous body: and since that
cloud is a mist, since it might have been the very evening mist
embodying a malaria, and since it is its real vehicle and repo-
sitory, it is plain that had it, or any individual cloud, contained
such a portion of malaria, it must have had the power of trans-
mitting that, and would actually have transported it to any
distance to which itself might travel. Thus, it is evident, may
a fog, generated in Holland, carry without difficulty to the
limits of its range, or to the coast of England, that malaria
which became entangled with it at its birth-place or in its
passage; and thus, I have little doubt, is the fact of those
agues explained, and this transportation to such distances
established.

I cannot, at least, conceive any demonstration as to facts of
this nature more convincing, nor anything wanting to the proof;
while I may proceed to make some remarks on the east wind,
and on fogs, simply, because they concern this question.

The proof that it is a malaria in the fog, and not the fog
itself, which is the cause of disease, is evinced by the following
fact; while it ought surely to be unnecessary to say, that if
fog alone could produce such fever, water itself must be the
poison : since a fog is a cloud, and its constituents, when pure,
are only atmospheric air and water. No intermittents are ever
produced on the western or northern shores by the sea fogs,
and for the plain reason, that there is no land whence they
arrive. The clouds of mountainous regions do not produce
fevers, though these also are fogs; and what forms a most
absolute proof of this is, that in Flanders, it is the fogs which
come with a southwest wind, or the southerly winds themselves,
which transport and propagate malaria and disease ; while, as
soon as the winds shift, and blow from the sea, the fevers dis-

On Malaria^ 49

appear, though those particular winds are so charged with fog,
as to darken the whole country for days : and it will be found
an invariable rule all over the world, that when a fog is the
apparent cause of disease, or when an east wind is such, it is
because these have been generated in a land of marshes, or
have traversed one ; and that, under other circumstances, or
where no pernicious land lies in the way, they are as innocent
as any other fogs and winds, and that the hazard and the suf-
fering will arise from those, be they whatever they may, which
traverse pestilential lands.

But I must defer this particular and interesting subject to
another occasion, lest I make this article too long ; and proceed
to examine some other circumstances connected with the
transportation of malaria.

First, however, I must notice one fact as to this transporta-
tion from Holland, partly because it is a necessary fact in the
history of malaria, and partly because it might be used as an
argument against the view which I have just given. The east
winds of autumn are not supposed to bring remittents, as those
of spring bring agues, though I cannot assert that this is abso-
lutely true. Being assumed, the solution is easy. If the winds
of this nature in spring are notedly moist, and thus vehicles of
malaria, the case is exactly the reverse with the east winds of
summer and autumn ; or as the east wind may be the most
moist of winds, so may it be the most dry ; while it is a conse^
quence of its extreme dryness, in fact, that it is always the
very cause of our burning summers. This is the history of our
last summers, and it is invariable, whether as it relates to sea-
sons or single days ; and it is plainly owing to its permitting
the more ready transmission of the sun's rays. That it is the
very harmattan of Africa, it is almost unnecessary to say ; and
as dry wind is not a conductor of malaria, as that poison is in
fact decomposed or destroyed in these circumstances, daily and
invariably, it is easy to see why the remittents of Holland
should not be transported, like its intermittents, though even
this may possibly happen under particular circumstances.

To proceed; and to the next remarkable facts connected
with the propagation of malaria. — The most singular of these is
its limitation, or that yet unexplained property by which it is

JULY— OCT. 1827. E

60 On Malaria,

determined in a particular direction, or confined to a particular
spot, while it is a piece of knowledge of some practical value.
There is an appearance of incredibility about many of these
facts, and, accordingly, they have not only been disbelieved
but ridiculed, although nothing in the whole history of this
substance is better established.

With respect to direction, in the first place, it is remarked in
Italy, currently, that this poison will enter the lower stories of
houses, particularly with open windows, when the next above
escape; and hence, in many places, no one ventures to sleep
on ground floors ; and the truth of this was confirmed in the
barracks at Jamaica by Dr. Hunter; as the cases of fever
occurring among the men in the lower rooms much exceeded
those which happened in the upper ones. But I am also in-
formed, that in some places in Norfolk this peculiarity is
reversed ; or that there are houses where it is remarked that
the ground-floors are safe, while no one can sleep in the upper
stories without hazard.

That malaria may in some manner be attached to the soil
is also well known by its effects, and especially in Italy. There
it is remarked that it is extremely hazardous to cut down cer-
tain bushy plants which appear to entangle it, and that fevers
are a frequent consequence of such carelessness. Thus, also,
does fever seize on the labourers who may incautiously sit down
on the ground, while they would escape in the erect posture ;
being thus, indeed, sometimes suddenly struck with apoplexy,
which is one of the effects of this poison, or even with death.

It has similarly been observed that it is often retained in the
shelter of drains, or in the ditches of fortifications; whence
frequent fevers among the sentries on particular guards, when
the other soldiers escape. And thus was it even proved at
Malta, that it was transported from the sea-shore, and thus
lodged in a dry ditch of the works at Valetta ; all these facts
being possibly to be explained, by supposing it possessed of a
greater specific gravity than the atmosphere, or else attached
to vapour thus weighty, exhibiting effects analogous to those
which carbonic acid displays in the Solfatara.

But the circumstance most difficult of explanation is, that in
Rome, and numerous places in Italy, and even where it is

.On Malaria. 61

transported from a distance by the winds, not generated on the
spot, it is found, perennially, and through the whole course of
successive years, to occupy certain places, and to avoid, as
constantly, others quite near, and, as far as the eye can judge,
equally exposed, and in all respects similar. Thus, one side
of a small garden, one side of a street, or one house, will be
for ever exposed to disease, or uninhabitable, when, at a few
feet or yards distant, the very same places are as constantly
free of danger : and thus it was found at the village of Faro,
in Sicily, that all the troops of our army quartered on one side
of the single street which formed it, were affected by fevers,
and suffered great mortality, while those on the other remained
in health.

But the most remarkable case of this nature known to me,
is a domestic one, and which rests on the testimony of thou-^
sands of persons, or of the whole country, however incredible
it may appear. It is, that between Chatham and Brighton,
including every town and single house, and Sittingbourne
among the rest, the ague affects the left hand side of the turn-
pike road, or the northern side, and does not touch the right
side, though the road itself forms the only line of separation.

We cannot as yet conjecture the cause of this very singular
circumstance or property, at least in cases of this nature;
though, under certain events of this kind, there are some facts
in meteorology that may offer a solution. These are the
notorious ones, that a hoar frost, or a dew, will sometimes be
found most accurately limited, both vertically and horizontally,
by a definite line ; stopping, for example, at a particular hedge,
and reaching to a certain altitude on a tree : but for the other
cases, we must yet wait for a period of more accurate know-
ledge as to this singular substance.

There is now one circumstance of importance, relating to
the destruction or decomposition of malaria, which must not
be passed over, from the interest of the facts depending on it:
this is, that its propagation is checked by the streets of a
crowded town, and apparently owing to this very cause, decom-
position. Thus it is observed, that the fever never appears in
the Judaicum of Rome, and, similarly, that the crowded streets
and the poor people escape, when the opulent houses and open

£ 2

58 On Malaria,

streets are attacked ; and hence the Villa Borghese, amon^
many other palaces and opulent houses in Rome, has been
abandoned, while such desertion, being limited exclusively to
houses where the air is most open and free, naturally excites
wonder : the cause, however, is now plain ; and thus it now
appears why it was that the Penitentiary in Westminster suf-
fered formerly from dysentery, originating in this cause, when
no such disease appeared among the neighbouring inhabitants.

And if this fact is of value as it may relate to the erection of
open streets in any place of this nature, it is most important
to point out what has been the continuous effect at Rome, as
the ultimate consequences threaten to be extremely serious.

It appears that from cutting down some forests which many
years ago occupied the declivities of the hills to the southward
of Rome, the malaria was let in upon that city from the Pon-
tine marshes; and, further, that the extirpation of a similar
wood to the eastward had let in the same poison upon another
quarter. Thus it has been found to enter the city through the
Porta del Popolo, while, for many years past, it has been gra-
dually extending its influence through the streets; leading
annually and successively to the abandonment of many houses
and palaces, and still annually increasing and extending its
ravages ; so as, at length, as I understand, to have even become
sensible at the Vatican. And the lines which it follows are
distinctly traced out by the inhabitants; while, as I have
already said, it is only the houses of the opulent Avhich suffer,
further than as the abandonment of these may also influence
the inferior ones in their neighbourhood.

Whatever the original cause may be, and however the direc-
tion, abstractedly, may be regulated by the winds and the
forms of the streets, or by local and fixed circumstances, it is
plain that the annual extension is the consequence of deser-
tion, and that as the inhabitants retire from before it, it
acquires the means of making a new step and a further pro-
gress; because thus they withdraw those fires and smoke, or
whatever else it be, dependent on human crowds, which decom-
poses and destroys this substance. And hence it must follow,
that as Rome shall become still further abandoned and depo-
pulated, from want of industry, or from political feebleness

On Malaria^ 53^

added to this cause, the effects must be expected to increase
in a sort of geometrical ratio ; almost leading to the fear that
the whole city itself may, in time, fall a victim to it, or be-
come abandoned to the wolves and mosquitoes.

If I dare not inquire more minutely in|o the remaining cir-
cumstances connected with the propagation of malaria, lest I
should extend this article to an inconvenient length, it is
necessary now to offer some remarks on prevention, and espe-
cially as it relates to this circumstance — the propagation of the
poison ; since the rules for prevention, as far as this relates to
production, may be deduced from what was said in a former
paper on this subject, and relate chiefly to the drainage of
lands, and to other practices, more or less obvious, which a
little reflection will, without much difficulty, deduce from what
was there said.

It is plain, in the first place, that as far as the winds are
concerned, it is by opposing obstacles to their course that we
must attempt to counteract or divert their influence ; and that,
in this case, it is through the use of trees alone that we possess
any power. Thus reversely, as in the case just stated, the
cutting down of trees and forests has often been a serious
cause of diseases in certain countries, by admitting a malaria
to particular spots; though it is easy to see that where any
given spot suffers from malaria, through condensation or con-
finement, the clearing away of these would be the remedy, by
attaining a free ventilation. To detail the particular modes in
which remedies may be applied through this species of aid, is
obviously unnecessary, and not easy, as it must depend on
local circumstances, differing for each place ; but I may re-
mark, as an example in illustration of my meaning, that where,
as in many of the narrow and prolonged valleys of Greece, the
sea shore is a marsh, the remedy would be to plant a screen of
trees beyond it, and thus to prevent the sea winds from passing
into the interior. And thus did the ancient Romans compel
the planting of trees on the shores of Latium, to check the
current from the Pontine marshes; rendering groves sacred,
under heavy penalties, and enacting other laws with the same
intentions.

With respect to such temporary precautions in these cases

f^ On Malaria,

as may concern armies in the field, or in camps, it is plain
that they will depend on attention to the courses and seasons
of the winds; while it would be abundantly easy to accumulate,
from the histories of campaigns, the most fearful examples of
mortality produced by neglect of these and similar precautions,
and even down to almost the very date at which I am writing :
and there can be no hesitation in saying, that an intimate and
accurate knowledge of every thing which concerns the produc-
tion and propagation of malaria, forms a most important branch
in that information necessary to a soldier, and above all to the
quarter-m aster-general's department and the medical staff:
while, did I dare to record but a very small portion of the
mortality experienced, not only in our own armies, but in those
of Europe at large, during even the last war, from ignorance
or neglect on this subject, it would, I believe, be found that
it almost equalled the mortality produced by the actual colli-
sion of war itself. Walcheren will not soon be forgotten ; if
we have ceased to think of our mortal Havannah expedition ;
and if a French army at Naples was diminished by twenty
thousand men, out of twenty-four, in four days, from this
cause ; if OrlofF lost nearly his entire army in Paros ; if Hun-
gary has more than once destroyed ten times the number of
men by fever that it did by the sword, — these are but trifles in
the mass of reasons for saying, that no subject can well be
more important, and no knowledge much more necessary to
the commander of an army.

Some other points relating to prevention may deserve a few
words of notice, before I pass from this subject; if here, also, I
must be brief Not to repeat the cautions founded on what
relates to the power of evening and morning, it has been
asserted that the use of a gauze veil will prevent the effect of
inalaria; and it is not improbable that the air accumulated
within that, may have the power of decomposing the poison :
it is an opinion, at least, which is universal among the people
in Malta, and very general in Spain and Portugal. It is also
found that fires and smoke are useful, and especially on military
service; the experiment having been tried on a very large
scale by Napoleon before Mantua, and on a smaller one in
Africa* with the most perfect success. With respect to per-

On Malaricu 85

sonal precautions, it is universally recommended to use wine
and a good diet, and especially never to leave the house in the
evening in situations peculiarly insalubrious, without the pre-
vious use of wine or spirits ; whence the universal practice of
Holland in this respect. Thus, also, narcotics prevent its
influence ; whence the wide use of tobacco, of which the salu-
tary effects appear to be most amply established.

As to the tropical countries, there is here also one important
remark, which, from the great neglect of the fact, and its ruin-
ous consequences, appear particularly to demand a statement
in this place. It is the universal experience of the inhabitants}
that the attack of malaria, or the production of fevers, is aided
by the use of a full or animal diet; by the use of some parti-
cular articles of food, such as butter; by excess in eating, gene-
rally ; and, above all, by eating in the heat of the day. This is
not merely well known to the negroes, but the fact is distinctly
stated to travellers, and the caution urged, however often it has
been neglected, and especially by our own countrymen. Of
this, in particular, Major Denham is a strong testimony ; while
he attributes his own exclusive preservation to his having
rigidly followed the recommendations of the natives, which
Were always urged with the greatest earnestness. And if we
examine the causes of death, in most cases, of our African
travellers especially, I think there will be strong reasons for
believing that their lives have often been sacrificed to this very
negligence or obstinacy ; while it is most evident that Niebuhr's
party, in particular, owed the loss of their lives to ^^ilat may be
safely called gluttony : and it is to be suspected that this will
also explain the loss of Captain Tuckey's party; while, with
respect to nations, it has long been known that the English,
the Dutch, and the northern voracious people in general, who
habitually indulge themselves in the customs of their original
country as tropical colonists, have always been greater sufferers
from the effects of those climates than the French and the
Spaniards, and apparently from this very difference. And
there seems little doubt, generally, that the \,egetable diet of
Africa and Hindostan is the best security against the evil
influence of those climates, and that the chief sufferings of our

S6 On Malaria^

own colonists arise from transferring to those situations their
ancient habits of full and free living.

As I must not prolong this subject much further, I shall
now pass to a few remarks, but very brief ones, on the
geography of malaria as it relates to those parts of the conti-
nent of Europe most frequented by English travellers; not
daring to take room for actual and useful information on that
head, but wishing to point out merely the importance of such
geographical knowledge to those persons, on account of the
hazards which they so universally incur from that ignorance or
neglect, and of the great mass of suffering, and also of mor-
tality, which has been the lot of persons who had resorted to
those climates as travellers, or migrating residents, from various
motives, and not unfrequently Avith views to health. How
often health has been lost where it was sought, will be but too
apparent to any one who has chanced to possess an extensive
acquaintance of this nature.

Of Italy I can but afford to say generally, that except at a
very few points where the Alps or Apennines reach the sea,
the whole of its shores are pestilential, and often to such a
degree as to lead to their entire desertion, more frequently to
their abandonment in summer. And to avoid wet lands, or
low lands, is not always a sufficient precaution ; since the most
pestilential parts of the maremma of Tuscany are dry, and
since the annual mortality of Sienna from fevers, even without
epidemics, is one in ten. In the north of Italy, the great plain
is similarly insalubrious ; though the more unhealthy district
does not commence until we arrive at Mantua, extending thence
to the sea. Of the Mediterranean islands, I can only afford
room to say, that the same rule holds good as to the sea coasts,
while the entire of Greece in the same circumstances is simi-
larly unhealthy, and subject to autumnal fevers in as great a
degree as the worst parts of Italy. The same is true of Spain
and Portugal, and the same rule also will be a guide ; namely,
that malaria is to be expected in all the flat grounds, even
when under cultivation, and at all the exits of rivers on the
sea, even though no marshes should be present: and if I were
desirous to name any tract of land in Spain peculiarly insalu-

On Malaria, QK

brious, it would be the province of Valencia; while Carthagena
is almost invariably fatal even to those who, as labourers, are
compelled to resort to it for the needful work of its port, even
during a few days.

Of France, little as it has hitherto been suspected by those
who, associating the term malaria with Italy, have been accus-
tomed to consider it as peculiar to that country, it would
scarcely be untrue to say that it contains as large a portion of
insalubrious territory as Italy itself, and produces fever and
disease of as great severity and extent, not merely on its sea
coasts, but over very extensive tracts in its interior. And this
insalubrity may be conjectured, when there are entire districts
in which the average of life does not exceed twenty, and in
which the entire people are diseased from their births to their
graves. Such tracts are found chiefly on the course of the
Loire, and some other of the great rivers; and among them,
Bresse in the Lyonnais, the plain of Forez, and Sologne in the
Orleannais, are of the most notorious ; while the coasts of
Normandy, and the whole of low Britanny, are similarly sub-
ject to eternal intermittents, or to epidemic seasons of autumnal
fevers, amounting to absolute pestilences. And how English
families have suffered in this country from the incautious
choice of residences in such places, will be easily ascertained
by whoever shall be at the trouble of making the necessary
inquiries.

But as I dare not pursue this extensive subject, I can only
suggest to our countrymen the utility of making themselves
acquainted with this matter, and with this dangerous geo-
graphy, before encountering the hazards which await them;
Avhile to physicians I need still less name the necessity of that
knowledge, since it is so often their duty to choose and recom^
mend for their patients, and since no man can feel much at his
ease who finds that he has sent into a land of malaria the
patient who has already been suffering from its diseases, or
that where he speculates on the cure of a consumption, that
cure is attained through the death of the patient, at Avignon,
or at Poitiers, or Nantes, or in some or other of the numerous
places subject to this most fearful poison.

It remains only to give a brief enumeration of the disesises

6S On Malaridk

which are the produce of malaria, and of the general condition
of the inhabitants in the countries subject to it. With respect
to this latter, the most remarkable general fact is the con-
tracted duration of life. In England, the average may, if not
very accurately, and indeed considerably under the mark, be
taken at 50 ; and when in Holland it is but 25, it follows that
the half of human hfe is at once cut off by this destructive
agent. In the parts of France to which I have alluded, it
becomes as low as 22 and 20, and Condorcet, indeed, has cal-
culated it as low as 18. With this, very few attain the age of
60 ; and in appearance and strength, this term is equivalent to
80 in ordinary climates ; while 40 forms the general limit of
extreme and rare old age. The period of age, indeed, com-
mences after 20 ; and it is remarked, in particular, that the
females become old in appearance immediately after 17, and
have, even at 20, the aspect of old women . In many places,
even the children are diseased from their birth ; while the life
which is dragged on by the whole population, is a life of per-
petual disease, and most frequently of inveterate and incurable
intermittents, or of a constant febrile state, with debility, affec-
tions of the stomach, dropsy, and far more than I need here
enumerate.

While the countenances of the people in those countries are
Sallow or yellow, and often livid, they are frequently so ema-
ciated as to appear like walking spectres, though the abdomen
is generally enlarged, in consequence either of visceral affec-
tions or dropsy. With these, rickets, varices, hernia, and, in
females, chlorosis, together with scorbutic diseases, ulcers, and
feo forth, are common ; and it is even to be suspected that the
cretinage may depend on this cause, since goitre is also one
of the results of malaria, and since, in the Maremma of
Tuscany, idiotism is a noted consequence of this pestilential
influence.

The general mental condition is no less remarkable ; since
it consists in an universal apathy, recklessness, indolence, and
melancholy, added to a fatalism which prevents them from
even desiring to better their condition, or to avoid such portion
of the evils around them as care and attention might diminish:
aad while it is asserted that even the moral character becomes

On Malaria, 59

similarly depraved, I prefer a reference to Montfalcon for a
picture which it would not be very agreeable to transcribe.

As to the absolute or positive diseases, besides those which
I have already named, 1 need scarcely say that remittent and
intermittent fevers, under endless varieties and types, form the
great mass; and next in order to them, may be placed dysen-
tery and cholera, together with diarrhoea. To these I must
also add, those painful diseases of the nerves, of which sciatica
stands foremost, and the remainder of which may be ranked
under the general term of neuralgia ; and further, a consider-
able number of inflammatory diseases of a more or less remit-
tent type, among which rheumatism under various forms is
the most general, and the intermittent ophthalmia the most
remarkable. Lastly, I must include the various paralytic
affections ; since apoplexy is one of the primary and direct
consequences of malaria, as various paralytic affections are the
produce of intermittent, or the consequences of the diseases of
the nerves which are associated with it.

It is still a curious and interesting fact, that this poison
affects, in an analogous manner, many different animals, and
appears, in reality, to be the cause of all the noted endemics
and remarkable epidemics which occur in the agricultural
animals in particular. This has been noticed even by Livy:
and in France and Italy it is equally familiar that the severe
seasons of fever among the people are similarly seasons of
epidemics to black-cattle and sheep, while the symptoms are
as nearly the same as they could be in the circumstances, and
the appearances on dissection also correspond. Thus also
does it appear probable, that the rot in sheep is actually the
produce of malaria, as is indeed the received opinion among
French veterinarians; while Mr. Royston has observed that
the animals of this class are subject to distinct intermittents.

And while it is not less familiar in the West Indies, and in
Dominica particularly, that dogs suffer from a mortal fever in
the same seasons and periods as the people, the epidemic
always breaking out in them first, I have the most unexcep-
tionable medical evidence of the occurrence of a regular and-
well-marked tertian in a dog; that evidence consisting in the
concurring decision of many surgeons, by whom the case was

6(1 On Malaria.

frequently examined, during a very long period. But it is
time to terminate a paper, which, if it is but a sketch of an
important subject, will at least convey to those to whom mal-
aria has not hitherto been an object of attention^ a general
notion of the leading particulars which appertain to its natural
history. J. M.

Elements of Chemistry, including the recent Discoveries and
Doctri7ies of the Science. By Edward Turner, M.D.,
F.R.S.E., &c., &c. Edinburgh, 1827.

This is a closely- printed octavo of 700 pages, and presents
us with something more original, clear, and accurate than
we have lately met with in modern chemistry. It compre-
hends a perspicuous view of the present state of chemical
science ; and, as far as its limits admit, the theoretical parts
are, with some exceptions, well and distinctly worked out ;
nor are the practical details of manipulation neglected,
though they evidently occupy a secondary place in our
author's estimation. To the arrangement we must at once
decidedly object — it is indeed evident that Dr. Turner has
pitched upon Dr. Thomas Thomson as his magnus Apollo ^
and here and elsewhere the book is tainted accordingly.

This work is divided into four principal parts; — the first
relates to what Dr. Turner, following his prototype. Dr.
Thomson, calls imponderables, and a definition of them fol-
lows, which leads us to suggest the term inexpressibles, as
equally appropriate. But, waiving this objection, the details
relating to them are well and clearly given. Thus, after
some prefatory remarks upon the subject of caloric or heat,
(we prefer the latter term, and cannot allow its ambiguity,)
its modes of communication are considered, first, as being
conducted through bodies, and then as radiating through
free space. In regard to the theories affecting the latter,
our author wisely, as we think, prefers that of Prevost to
that of Pictet. The effects of heat are next discussed, such
as expansion, including an account of the thermometer,
and of the relative capacities of bodies for heat; lique-
faction, vaporisation, ebullition, evaporation, and the con-
stitution of gases ; and lastly, the sources of heat are
mentioned, but the details are referred to other parts of the
work.

Dr. Turner's Elements of Chemistry. 6t

Light is next treated of, but we think too hastily, and too
much in the abstract.

Now the subjects of heat and light are obviously of the
utmost importance to the chemical philosopher, and they are
very extensive, and intricate and difficult to treat of, inasmuch
as the writer is necessarily upon the confines of chemical and
mechanical philosophy, and should be expert in both. When,
therefore, elementary works on chemistry are so written and
arranged as to serve as text-books for lectures, and indexes
of reference to more accurate information, we can make due
allowance for brevity ; but when the subject is intended to
be formally and completely developed to the student, inde-
pendent of other ocular and oral aids, much more extensive
description and detailed explanation is required, than is to
be found either in our author's '* Elements," or in any other
analogous condensation of chemistry. Dr. Henry under-
stands the requisite mode of conveying information in these
cases better than most writers ; and when he takes pains,
and speaks for himself, has the talent of being brief, and at
the same time minute, deep, and clear. Dr. Ure, as his
dictionary shows, is an eminent example of such a writer — >
he of course is neglected, where, as with our author, Dr.
Thomson is in the ascendant; but the article caloric, in his
dictionary, will at once explain and illustrate our meaning,
and would furnish an admirable foundation for a detailed
essay or treatise upon the subject. So extensive, indeed,
are the precincts of chemistry now becoming, that either
our systems must become very voluminous, or we must
adopt the plan, which to us appears preferable, of distinct
treatises upon different branches of the science. Thus, a
separate work on heat and light ; another on electricity and
magnetism ; another on attraction and the theory of combi-
nation ; a fourth on the constitution and properties of the
unmetallic elementary bodies ; a fifth on the metals and their
compounds; a sixth on vegetable, and a seventh on animal
chemistry and physiology ; an eighth on the chemistry of the
arts ; and lastly, a treatise on chemical manipulation in ge-
neral, would include all that appears essentially requisite ;
and as no one is supposed to be equally well versed in all
branches of the science, or in all details of the art, an
opportunity of selection would thus be afforded, so that each
writer might choose that particular department which he is
most accurately acquainted with, or which has formed his
favourite study. Mr. Faraday has already, as may be said,
led the way in such a plan, by the publication of his Chemi-

M Dr. Turner'^ Elements of Chemistry,

cat Manipulation, a work hitherto exceedingly wanted in
the laboratory, equally useful to the proficient and to the
student, and eminently creditable to the industry and skill
of the author, and to the school whence it emanates. We
shall of course take an early opportunity of introducing this
book in a more formal way to the attention of our chemical
readers.

In looking over Dr. Turner's first and second sections on
caloric and light, in the Elements now before us, we find
little but brevity to complain of; — there are, however, one
or two trifling historical inaccuracies : thus, at page 14, the
discovery of invisible heating rays is ascribed to Saussure
and Pictet ; but it is, in fact, of much more remote origin — •
it was well known to the Florentine academicians, and we
may even trace the idea in Lucretius, (De Rerum Naturd^
lib. V. 1. 609.)

Forsitan et rosea Sol alte lampade lucens
Possideat multum ccecis fervoribus ignem
Circum se, nullo qui sit fulgore notatus, <^c.

At page 31 we have an account of Wedgwood's pyrome-
ter, which is said to be *' little employed at present, because
its indications cannot be relied on ;" — the fact is, that it is
never used, and that we owe to Sir James Hall ample rea-
sons for placing no confidence in it.

The subject of specific heat is clearly explained, and so are
the phenomena of liquefaction and evaporation. In regard
to the constitution of gases, the author remarks, that the ex-
periments of Sir H. Davy and Mr. Faraday on the liquefac-
tion of gaseous substances, appear to justify the opinion that
gases are merely the vapours of extremely volatile liquids.
Mr. Faraday has proved this in regard to several of the gases,
and analogy leads us to apply it to the rest ; — but what share
Sir H. Davy had in the discovery, we know not ; for Mr. Fa-
raday actually condensed chlorine into a liquid before Sir H.
had heard or thought about the matter. Light, and its
phenomena as connected with chemistry, is superficially
passed over in the second section, and the third brings us
to the important article '* Electricity."

We are willing to admit that the subject of electricity is
a very difficult one for the chemist to deal with — he must
necessarily say much upon it, and is equally obliged to omit
abstract details which are often necessary to its explanation,
and yet too prolix and bulky for an elementary chemical
work. So that it requires considerable acquaintance with
the subject to give a perspicuous and yet concise abstract,

Dr. Turner's Elements of Chemistry, 63

such as may be useful to the student. Dr. Turner has not
been very successful in effecting this desideratum, and has
unnecessarily introduced two sections, the one on electricity,
the other on galvanism. He also talks of the ** science of
galvanism," which is in bad taste, and erroneously asserts
that the energy of the pile is proportional to the degree of
chemical action which takes place ; a statement by no means
correct, inasmuch as the energy of De Luc's column is directly
proportional tothe number of alternations, andappears entirely
independent of chemical action ; and again, a series of 2000
plates, arranged in the usual Voltaic apparatus, when per-
fectly bright and clean, and the cells filled with distilled
water only, give a much more powerful shock, and cause
a greater divergence of the leaves of the electrometer than
when the apparatus is charged with diluted acids. Here,
those very singular phenomena, which electricians distin-
guish by the terms quantity and intensity, appear perfectly
distinct ; and between these our author does not sufficiently
discriminate, but jumbles the whole under the term activity.
In describing the chemical energies, too, of the pile, or its
decomposing powers, the Doctor entirely overlooks the im-
portant andf curious influence of water. He says that acid^
and salts are all decomposed, without exception, one of their
elements appearing at one side of the battery, and the other
at its opposite extremity ; {i. e. we presume, at its positive
and negative poles.) But the fact is, that, excepting where it
merely acts as a source of heat, nothing is decomposable by
electricity without the intervention of water ; the hydrogen
and oxygen of which respectively accompany the elements of
the other compounds. Not an atom of potassium can be
obtained unless the potassa be moistened ; nor can any salt
be decomposed except water be present. Sir Humphry
says, it is required, to render the substance a conductor ;
but its operation is more recondite, and there is something
mysterious and still unexplained in the uniform appearance of
hydrogen and oxygen at the opposite poles, when far apart
in water, and in all other cases of true polar electro-chemical
decomposition. At page 86, the unfortunate protectors of
ships' bottoms are introduced — a subject about which the less
is said the better ; — ^and, as to electro-magnetism, it is merely
mentioned as to its leading phenomena, in the space of three
or four pages; nor is anything new suggested upon the
♦' Theory of the Pile," as it is called, which concludes the
subject, and which is dismissed in the brief limit of a pag«
iMid a half.

64 Dr. Turner'^ Elements of Chemistry,

The second part of Dr. Turner's work is said to comprise
^* Inorganic Chemistry," and therefore embraces a very ex-
tensive field of inquiry. To the arrangement we have
already objected; and many of the typographical and verbal
errors that occur, have been noticed in a contemporary
Journal, so that we shall chiefly attend to the details of the
sections.

Under the head *« Affinity," some of the leading facts
and doctrines of chemical attraction are perspicuously set
forth; but we could have wished that a variety of exploded
opinions and erroneous notions had been altogether passed
over, as they occupy space which might have been better
employed, and can never prove of any other use to the stu-
dent than to show him the errors and fallacies to which acute
philosophers are sometimes liable. Of this kind, espe-
cially, are Berthollet's notions upon the subject of affinity.
The doctrine of definite proportion is, on the whole, well and
clearly explained ; but it would have been much better
and clearer, had Dr. Turner confined himself to facts, and
meddled less with opinions concerning their cause ; he is
moreover, in many respects, historically inaccurate. He
ascribes much to Dalton that honestly belongs to Higgins; —
is much too merciful to Berzelius and his Canons ; and
lenient beyond all endurance to the plagiarisms of *' Dr.
Thomson's admirable Treatise on the first Principles of Che-
mistry."

In the third and following sections, the simple non-metallic
substances are described in an order of arrangement which
must be very perplexing to the student ; otherwise the details
are well given, except that here and there the line between
theory and fact is not sufficiently marked. Thus we are
told that " hydrogen is exactly 16 times lighter than oxygen,
and therefore that 100 cubic inches must weigh il±liL, or

2.118. Its specific gravity is consequently 0.0694, as stated
some years ago by Dr. Prout." Now this is a theoretical
deduction, founded upon the specific gravity and constitution
of ammonia, (and not upon the composition of water,) and
probably correct as applied to jjure hydrogen ; — but if we
weigh the gas, as usually obtained, even with the utmost
caution, and of the utmost purity, we shall never procure it
so light as here stated, notwithstanding all the learning and
argument that our worthy friend. Dr. Thomas Thomson, has
issued upon the subject in his various essays in the Annals,
and in his magnum opus. We also object to the stress
which is often laid upon the whims of individuals, and upon

Dr. Turner'5 Elements of Chemistry, 65

exploded opinions; instances of which will occur to the
reader under the subject of the composition of nitrogen,
and the constitution of the atmosphere. We further caution
our author against admitting hints, allusions, and inuendos
as to the possibility of future inventions and discoveries,
as claims upon the merits of such discoveries, when they are
actually made. Berzelius has talked a vast deal of non-
sense about the composition of nitrogen ; and should that
discovery ever be made, he will doubtlessly assume the credit
of having suggested the steps which led to it. Some foolish
persons are apt to think that the Marquis of Worcester was
the inventor of Watt's steam-engine, because he said he
had means of raising water by steam, in his Century of
Inventions; and we have heard that an eminent chemist of
the present day considers himself entitled to all the merit
that may belong to Mr. Brunei's carbonic acid engine, be-
cause he had previously stated the possibility of such an
application of Mr. Faraday's important discoveries. The
fact is, that these are woeful days for science ; all the good
feeling and free communication that used to exist among its
active cultivators in this country, has given way to petty
jealousies and quibbling scandal ; one person is exalted for the
purpose of depreciating another ; and those causes of disgust,
which some years ago induced one of our most amiable and
able men of science to quit the field, and even leave the coun-
try, are becoming daily more prevalent. Were it not an invi-
dious task, we could easily explain and unfold the sources of
all this mischief, and shall indeed feel it our duty so to do,
should not matters in due time take a more favourable turn ;
but the task is at once serious and disagreeable, and we
therefore postpone it, in the hope of more favourable events.
We really believe that, had it not been for the scientific con-
versationes held during the last seasonat the houses of a few
private gentlemen connected with the learned societies, and
more especially the weekly meetings at the Royal Institution,
which kept up a friendlv intercourse among those who were
willing to profit by it, tliat the whole scientific world would
have been at loggerheads, and in that state of anarchy of
which the evils may be learned by a short residence at a
•* northern seat of learning."

The main object of this digression is to deprecate party in
science ; and we were led to it by observing, or thinking
that we observe, something of such a tendency in the writer
whose book is before us — we hope we are mistaken.

The next section comprises <* the compounds of the simple
JULY— OCT. 1827. F

^ Pr. Turner's Elements of Chemistry^

.non-metallic acidifiable combustibles with each other." It
includes the important subject of ammonia, of the varieties
of carburetted hydrogen, sulphuretted and phosphuretted
hydrogen, and cyanogen and its compounds. The metals are
then treated of, and to these succeed their salts ; and
though the execution of this part of the work betrays some
.haste, it shows also considerable reading, and some origin-
ality : the general views are well and clearly sketched, but
there are many points upon which we are entirely at variance
with our author ; and we more especially object to his ac-
count of the action of chlorides upon water, and to his notions
concerning the ** muriates of oxides," a class of compounds
of which, with one or two exceptions, we are disinclined to
admit the existence. If common salt be a chloride of sodium,
and experiment obliges us so to regard it, what is there in
its aqueous solution that should lead us to consider it as
containing a muriate of soda ; what evidence of any new
arrangement of elements ? Dr. T. is certainly in mistake,
when he says, " for all practical purposes, therefore, the
solution of a metallic chloride in water may be viewed as
the muriate of an oxide, and on this account I shall always
regard it as such in the present treatise." This inconside-
rate dogma taints much of the reasoning upon the chlo-
rides, &c., and is manifestly culled in the Thomsonian school,
though we have indeed heard that a Professor at Edinburgh
thus addresses his pupils upon the above subject: "The
elaborate researches of the illustrious Davy have taught us
that common salt is a binary compound of chlorine and
sodium, a chloride, therefore, or a chloruret of sodium. But
it is only chloride of sodium whilst quiescent in the salt-
cellar ; for no sooner does it come into contact with the
salivary humidity of the fauces, than, by the play of affini-
ties, which I have elsewhere explained, the sodium becomes
Boda, and the chlorine generates muriatic acid ; — that,
therefore, which upon the table is chloride of sodium, is
muriate of soda in the mouth ; and this again, when desic-
cated or deprived of humidity, retrogrades into its former
state."

Dr. Turner again falls into error, as we humbly conceivCj
in calling certain salts, such, for instance, as those of the per-
oxide of iron, sesquisalts, a term properly applied in those
cases only where one proportional of a protoxide unites with
one and a half of an acid, such for instance as the sesquicar-
bonate of soda, &c., but in the sesquisulphate of iron, one
proportional of the peroxide contains 1.5 of oxygen, and ne-

Dr. Turner's Elements of Chemistry. 67

cessarily, therefore, (according to Berzelius' canon, if the Doc-»
tor pleases,) requires 1.5 of acid to convert it into a salt; just
as the commonly constituted peroxides (containing two pro^
portionals of oxygen) require two of acid. Dr. Thomson,
with all his nomenclatural pretensions, has fallen into the same
error.

The part of our author's work which treats of the che-
mistry of organic bodies is, upon the whole, an unexception-
able and accurate epitome of that complicated branch of the
science. It has its inaccuracies, but they apparently arise out
of the difficulty of condensing into the space of a few pages,
matter which, as we have elsewhere remarked, would require
an ample volume for its extended and perspicuous details.

In our hasty account of this work, we have rather dwelt
upon its defects than its merits, in the hope of seeing another
and more extended edition, free from what we consider as
serious obstacles to the success and usefulness of the present
production. We hope that Dr. Turner will not feel offended
at the freedom with which our remarks are offered. We are
anxious that a writer of such good information should be in-
duced to think for himself; at least, that he should accurately
weigh the pretensions, and inquire into the originality of those
views and researches upon which he bestows such unquali-
fied and, in our opinion, undeserved praise, and to which he
assents with a facility unbecoming one who evidently possesses
the means of testing their merits.

Experiments on Audition.

[Communicated by Mr. C. Wheatstone.]

The recent valuable experiments of Savart* and of Dr, Wollas-
ton have added to our stock of information several important
and hitherto unnoticed phenomena relating to audition; bu^
notwithstanding the investigations of these distinguished experi-
mentalists, and though the physiology of the ear has beeh'^an
object of unceasing attention for many centuries, yet we are far
from possessing a perfect knowledge of the functions of the
various parts of this organ. The description of new facts illus-
trative of this subject cannot, thereforie, be devoid of interest;

* Recherches sur les usages de la membrane du tympan et de I'oreiUe
exteme^ par M. Felix Savart. AnncUes de Chimie, torn. xxvi. p. 1.

F 2

€8 Experiments on Audition.

and though I do not anticipate that the observations contained
in this communication will lead to any important results, their
novelty may claim for them some attention from the readers of
your Journal-

5 1-

If the hand be placed so as to cover the ear, or if the en-
trance of the meatus auditorius be closed by the finger without
pressure, the perception of external sounds will be considerably
diminished, but the sounds of the voice produced internally will
be greatly augmented : the pronunciation of those vowels in
which the cavity of the mouth is the most closed, as e on, &c,,
produce the strongest effect ; on articulating smartly the sylla-
bles te and kew, the sound will be painfully loud.

Placing the conducting stem of a sounding tuning-fork* on
any part of the head, when the ears are closed as above de-
scribed, a similar augmentation of sound will be observed.
When one ear remains open, the sound will always be referred
to the closed ear, but when both ears are closed, the sound will
appear louder in that ear the nearer to which it is produced.
If, therefore, the tuning-fork be applied above the temporal
bone near either ear, it will be apparently heard by that ear
to which it is adjacent ; but on removing the hand from this ear
(although the fork remains in the same situation) the sound
will appear to be referred immediately to the opposite ear.

In the case of the vocal articulations, the augmentation is
accompanied by a reedy sound, occasioned by the strong agita-
tions of the tympanum. When the air in the meatus is com-
pressed against this membrane by pressing the hand close to the
ear, or when the eustachian tube is exhausted by the means
indicated by Dr. Wollaston, the reedy sound is no longer heard,
and the augmentation is considerably diminished. The ringing

• The tuning-fork consists of a four-sided metallic rod, bent so as to
form two equal and parallel branches, having a stem connected with the
lower curved part of the rod, and contained within the plane of the two
branches. The branches are caused to vibrate by striking one end
against a hard body, whilst the stem is held in the hand. The sound
produced by this instrument when insulated is very weak, and can only
be distinctly heard when its branches are brought close to the ear ; but
instantly its stem is connected with any surface capable of vibrating, a
great augmentation of sound ensues from the communicated vibrations.
ThQ facility of its insulation and communication renders it a very conve-
nient instrument for a variety of acoustical experiments.

Experiments on Audition* 69

noise which simultaneously accompanies a very intense sound,
proceeds from the same cause, and may be prevented by the
same means. This ringing may be produced by applying the
stem of a sounding tuning-fork to the hand when covering the
ear, or by whistling when a hearing trumpet is placed to the ear.
As a proof that the resulting augmentation, which, when great,
excites the vibrations of the tympanum, is owing to the recipro-
cation of the vibrations by the air contained within the closed
cavity, it may be mentioned, that when the entrance of the
meatus is closed by a fibrous substance, as wool, &c., no in-
crease is obtained.

If the meatus and the concha of one ear be filled with water,
the sounds above-mentioned will be referred to the cavity con-
taining the water in the same way as when it contained air, and
was closed by the hand ; it will be indifferent whether any par-
tition be interposed between the cavity and the external air, as
the water is equally well insulated by a surface of air as by a
solid body*

The preceding experiments have shown, that sounds immedi-
ately communicated to the closed meatus externus are very
greatly augmented ; and it is an obvious inference, that if ex^
ternal sounds can be communicated, so as to act on the cavity
in a similar manner, they must receive a corresponding aug-
mentation. The great intensity with which sound is trans-
mitted by solid rods, at the same time that its diffusion is pre-
vented, affords a ready means of effecting this purpose, and of
constructing an instrument, which, from its rendering audible
the weakest sounds, may with propriety be named a Microphone.

Procure two flat pieces of plated metal, each sufficiently large
to cover the external ear, to the form also of which they may
be adapted ; on the outside of each plate directly opposite the
meatus, rivet a rod of iron or brass wire about 16 inches in
length, and one-eighth of an inch in diameter, and fasten the
two rods together at their unfixed extremities, so as to meet in
a single point. The rods must be so curved, that when the
plates are applied to the ears, each rod may at one end be per-
pendicularly inserted into its corresponding plate, and at the
other end may meet before the head in the plane of the mesial

TO Experiments on Audition,

line. The spring of the rods will be sufficient to fix the plates^

to the ears, but for greater security ribands may be attached
to each rod near its insertion iii the plate, and be tied behind
the head.

A more simple instrument may be constructed to be applied
to one ear only, by inserting a straight rod perpendicularly into
a similar plate to those described above.

The Microphone is calculated only for hearing sounds when
it. is in immediate contact with sonorous bodies ; when^ they
are diffused by their transmission through the air, this instru-
ment will not afford the slightest assistance.

It is not my intention in this place to detail all the various
experiments which may be made with this instrument, a few
will suffice to enable the experimenter to vary them at his
pleasure.

• 1. If a bell be rung in a vessel of water, and the point of the*
microphone be placed in the water at different distances from
the bell, the differences of intensity will be very sensible. 2. If
the point of the microphone be applied to the sides of a vessel
containing a boiling liquid, or if it be placed in the liquid itself,
the various sounds which are rendered may be heard very dis-
tinctly. 3. The instrument affords a means of ascertaining,
with considerable accuracy, the points of a sonorous body
at which the intensity of vibration is the greatest or least ;
thus, placing its point on different parts of the sounding board
of a violin or guitar, whilst one of its strings is in vibration, the
points of greatest and least vibration are easily distinguished.
4. If the stem of a sounding tuning-fork be brought in contact
with any part of the microphone^ and at the same time a musi-
cal sound be produced by the voice, the most uninitiated ear

Experiments on Auditimi. W

will be able to perceive the consonance or dissonance of the
two sounds ; the roughness of discords, and the beatings of im-
perfect consonances, are thereby rendered so extremely dis-
agreeable, and form so evident a contrast to the agreeable har-
mony and smoothness of two perfectly consonant sounds, that
it is impossible that they can be confounded,

§3-

Apply the broad sides of two sounding tuning-forks, both being
unisons, to the same ear ; on removing one fork to the opposite
dar, allowing the other to remain, the sensation will be consi-
derably augmented.

It is well known, that when two consonant sounds are heard
together, a third sound results from the coincidences of their
vibrations ; and that this third sound, which is called the grave
harmonic, is always equal to unity, when the two primitive
sounds are represented by the lowest integral numbers. This
being premised, select two tuning-forks, the sounds of which
differ by. any consonant interval excepting the octave ; place the
broad sides of their branches, while in vibration, close to one
ear, in such a manner that they shall nearly touch at the acoustic
axis, the resulting grave harmonic will then be strongly audible,
combined with the two other sounds ; place afterwards one
fork to each ear, and the consonance will be heard much richer
rn volume, but no audible indications whatever of the third
sound will be perceived.

§4.
Very acute sounds, such' as the chirping of the gryllus cam-
pestris, &c., are rendered inaudible by exhausting the air from
the Eustachian tube, and thereby producing a tension of the
membrane of the tympanum ; the different thicknesses or ten-
sions of this membrane may therefore occasion that diversity of
the limits of audibility, with regard to the acute sounds which
Dr. Wollaston has pointed out as existing in different indivi-
duals ; if so, it would be desirable to ascertain this limit in in-
dividuals in whom the tympanum is perforated, or destroyed.

§5.
When the auricula is brought forward, all acute sounds are
rendered much more intense, but no sensible difference is per-

72i Experiments on Audition^

ceived with regard to the grave sounds. The higher tones of
glass staccados, or of an octave flute, the ticking of a watch, all
kinds of sibilant sounds, &c. are thus greatly augmented : the
experiment is easily tried, by whistling very shrill notes. A
still greater augmentation of the acute sounds is obtained, by
placing the hands formed into a concave behind the ears, and
by bending downwards the upper part of the auricula, so as to
obtain a more complete cavity.

I will conclude with the following observation : 1 had, in con-
sequence of a cold, a very slight pain in my left ear ; on sound-
ing the regular notes of the piano-forte, C and C* were much
louder than the others, and the loudness was much increased,
by placing the hand in the manner above described to the left
ear. When it was pressed close, or when the Eustachian tube
>vas closed, the intensities of all the notes were equalized, I
attribute this affection to the diminished tension of the mem-
brana tympani, which was again increased by the operation
described.

On the Petromyzon Marinus.

On entering the harbour of Dublin a few weeks ago, we were
becalmed off the Hill of Howth, and to pass the tedious time
until a breeze sprung up, we found some lines on board, and
began to fish from the quarter-deck. We caught a number of
grey gurnet ; but our attention was particularly attracted by a
pull of uncommon force on one of the lines. Having rendered
assistance to the person who held it, we were all astonished to
see rise out of the water a large fish, with apparently a double
body, which, after floundering on the surface of the water, we
pulled on deck. On examining this phenomenon for a short
time, we were again surprized to see it separate into two parts ;
and then found that there were two large fish taken up on the
same hook, the head of one having been buried under the throat
of the other, to which it had firmly attached itself. When se-
parated by force, it wriggled about on the deck with extraordi-
nary strength and agility, and again darted on its prey, to which

On the Petromyzon Marinus,

79

it adhered so firmly, that it required very considerable exertion
to detach it ; for it suffered itself to be raised up by the tail
and shaken, still holding the other fish suspended from its jaws.
When finally separated, it showed great ferocity, darting at every
thing near it, and at last seizing the deck, which it held very
fast, writhing with its tail and body as if in the act of tearing it
to pieces. When detached, its teeth left a deep circular im-
pression on the wood, the fibres of which were drawn into the
cavity of its jaws, so as to be raised up in the form of a cone.
I now directed, that it should be put into a bucket of sea water,
in the hope of preserving it alive until we arrived in Dublin, but
it died in a shorter time than could be expected, from the energy
and activity it had displayed, long after the other fish was dead.
We had handled it very roughly, and so perhaps had mortally
hurt an animal otherwise very tenacious of life.

On examining the fishes, I found that which had taken the

hook, was the gadusPolachius, or whiting Pollack. It was about
two feet long, and it is probable its active enemy had fastened

fS On the Petromyzon Marinus,

on it after ft had been hooked ; if before, it would indicate an
extraordinary insensibility to pain in an animal that could
attend to the calls of appetite, whilst another was preying on
its vitals. The fish which had fastened on the pollack, was the
petromyzon marinus, or sea lamprey. It was nearly three feet
long, and resembled a large eel in shape. Its general colour
was a dull brownish olive variegated with bluish blotches ; the
back darker, and the belly paler, inclining to yellow. The eyes
were small, and the mouth large and oval ; but when distended,
circular. The inside of the jaws was deeply concave, and
studded with circular rows of sharp triangular teeth, that issued
from corresponding orange-coloured papular protuberances,
which formed the gums ; the tongue was short and crescent-
shaped, furnished with a row of very small teeth round the
edge. On the top of the head was a small orifice, or spout-hole^
from whence it discharged the superfluous water taken at the
mouth. But the circumstance that more particularly distin-
guished it, was that which gave rise to the vulgar error that it
had sixteen eyes. On either side of the neck, commencing just
below the real eyes, was a row of seven equidistant spiracles
exactly resembhng eyes ; they are, however, holes lined with a
red membrane, and all opening into the mouth, an apparatus
to supply the place of gills, whose functions are to extract
oxygen from the water, and so perform the office of lungs in
aquatic animals. It had two dorsal fins, one on the lower part of
the back, narrow, with a roundish outline ; the other commencing
where the first termin.ated. The spine was cartilaginous, without
processes. The pericardium, containing a small heart, was a re-
markably strong membrane, and the liver was as green as grass.
This fish is not uncommon in the North Seas, though it most
abounds in the Mediterranean, where, from earliest times, it was
esteemed a luxurious dish. Fish-ponds were purposely con-
structed to preserve it. On our coast, Pennant observes, that it
is found most frequently at the mouth of the Severn, which river
it sometimes ascends, where it is occasionally taken, firmly
attached to a stone by its mouth, while its tail and body are
waving freely to the current. Its adhesion at such times is so
strong, that it may be lifted with a stone of twelve pounds
weight appended to its mouth. This faculty is owing to its

On ihe Petromyzon Marinu84 79

power of suction ; while the circumstance of its circular jaws
coming in close contact with the surface of the body excludes
the external air within the cavity of the mouth, and so adhereg
like the hand placed on the cup of an air-pump. It is from
this remarkable property, that its scientific name has been im-
posed*. Its vulgar name, lamprey, from lampetra, has a simi-
lar derivation. By the Romans it was named muraena. As
this fish was well known and highly prized by the ancients, there
is none that has been so frequently described and alluded to*
Aristotle, PUny, Tacitus, Columella, iElian, Seneca, and Oppian,
have mentioned its properties and habits, which correspond
exactly with those I have described above. Pliny says, in the
northern parts of France, and consequently contiguous to the
British Isles, the lampreys have seven spots in the jaws, re-
sembling the constellation of the plough, evidently the same as
the eyes, which vulgar opinion assigns to the fishf. Their ex-
treme voracity was such, that criminals were thrown among
them to be devoured. Seneca relates, that Vedius Pollio, a
Roman knight, ordered his seryant, who had broken u crystal
vase, to be thrown into a large pond of lampreys J ; and Colu-
mella writes, that they were sometimes seized with a rabid fury;
that resembled canine madness ; in the access of which, they
seized upon other fish, so that it was impossible to keep them
in the same pond § ; and to account for this extraordinary fero-
city, Oppian and others assert, that the lamprey is impregnated
by a serpent ; the one issuing from the sea, and the other rush-
ing down to the rocks, inflamed with madness, to consummate
the impregnation ; and adds, that the extraordinary intercourse
was effected by the lamprey seizing the serpent's head in its

* Petromyzon, a tst^ov, saxura, and /^v^eta, sugere.

t In Gallia septentrionale mursenis omnibus dextra in maxilla septenae
maculae ad formam septentrionis aureo colore fulgent.

Plin. Hist. Nat. lib. ix. cap. 39.

X Fregerat unus ex servis crystallinum ejus ; rapi eum Vedius jussit,
nee vulgari quadam morte periturum, muraenis objici jubebatur quas
ingens piscina continebat. — Seneca de Ira, lib. ii. cap. 40.

§ Commisceri eas cum alterius notae piscibus non placet, quasi rabie
vexantur quod huic generi velut canino solet accidere. Saevitia perse-
quuntur squamosos plurimosque mandendo consumunt.

Columella de Me Busticdj lib. ix. cap. 1 7.

76 On the Petromyzon Marinus*

mouth*. This singular copulation was the reason "why the
jRomans, who were immoderately fond of lampreys, did not
wish to eat them, when impregnated by the supposed serpent.
Horace, therefore, makes Nasidienus, among the blunders of
his supper, serve it in that state -j-.

. Lampreys w^ere a favourite dish with our own early monarchs.
Henry II. died by eating them to excess. The celebrated Pope
also owed his death to a surfeit of them. Doctor Johnson re-
marks in his life of the poet, that he was in the habit of cook-
ing them himself in a silver saucepan. The Corporation of
Oxford still make up a periodical pye of this fish for the king,
in compliance with ancient usage. But lampreys have lost
their rank at corporation feasts, in consequence of the more de-
licious and wholesome turtle being introduced into modern
cookery.

I have never noticed lampreys in the Dublin fish-market ;
and though they are frequently used in the South of Ireland, I
do not know if they have ever been made an article of food in
Dublin, or the north, where they are rarely met with.

C.

Observations upon the Motion of the Leaves of the Mimosa

Pudica.
[To the Editor of the Quarterly Journal of Science J
Dear Sir,

Towards the latter part of this summer, Mr. Gilbert Burnett
and myself made several experiments with a view to ascertain
the nature of the movements exhibited by the sensitive plant.
We aftenvards found that the greater part of the facts which
we had observed, had been previously described by Mr. Lind-

"Clg fiiv ya.[jt.u n xcci i^ oikos ip;\^iTixi aurn

Tlpo(p^uv Ifcitovcra •xa.f tfjiUfovTi ya.fJi.oio

Hrei fiiv (pXoyvA rshufiivo; ivloSt Xvffff^

Ma7vtTa/ 'iti (piXorriToc kcci 'iyyv^i ffVfUTcr.t ccxrn;

Uixpo; o(pis. x.r.x. — OrPiAN, Halieut. lib. i. V. 554.

t Adfertur squillas inter mvirsena natantes.
In patina porrecta : *' haec gravida," inquit,
*' Capta est;'— Hon. lib. ii. Sat. 8. lin. 46.

On the Leaves of the Sensitive Plant. 77

say and Dr. Dutrochet. Mr. Lindsay's observations are to be
met with in a MS. preserved in the hbrary of the Royal
Society, which is dated July 1790 : this essay is alluded to by
Dr. Smith in his ♦* Introduction to Botany." Dr. Dutrochet's
experiments were published in his " Recherches anatomiques
et physiologiques sur la Structure intime des Animaux et des
Vegetaux," which appeared in 1824. With the latter author
the reputation of originality is likely to rest : not undeservedly,
indeed, as there is no reason to suppose that his experiments
were suggested by a knowledge of those performed by Lindsay.
It is, however, an act of literary justice to secure to Mr. Lindsay
the credit of undoubted priority in describing the phenomena
which he noticed in common with Dutrochet. I have drawn
up the following remarks partly for this purpose — partly to have
an opportunity of mentioning some circumstances which escaped
the observation of both experimentalists.

The leaves of the Mimosa Pudica consist either of one or
two or three pairs of leaflets, and occasionally terminate by an
odd one. Each leaflet bears from twenty to sixty subleaflets,
which are disposed in pairs. The petiole or stalk of each leaf,
at the extremity which is attached to the branch or stem of the
peant, swells into an intumescence varying from three to five
in length. A similar intumescence, of proportionate dimen-
sions, is seen upon each subpetiole, where it is articulated with
the petiole, and upon the base of the stalk of each subleaflet ;
the intumescence is the part in which motion takes place.

During the day-time the petioles are obseiTed to have a
direction upwards, or rather to form an acute angle with the
upper part of the stem or branch, to which they are attached :
the subpetioles are divergent : the subleaflets are spread out, so
as to lie nearly in one plane. {Fig. 1.)

During the night the petioles are found to be depressed ;
the subpetioles to be drawn together, the subleaflets folded,
the upper or solar surfaces of each pair being brought into
contact. {Fig, 2.)

The leaves rise, the leaflets diverge, and open by throwing
down their subleaflets, at daybreak : the opposite changes occur
about sunset. The experiments that are to be described, are
supposed to be performed in the day-time..

TO

Observations upon the Motion of
Fig,u

If a terminal subleaflet be pinched
with forceps, or cut with scissors, it
rises, together with its fellow ; then the
.next pair rise ; then the next ; and so
on in succession, till all the pairs of
subleaflets upon the same subpetiole
are folded. In a little time afterwards,
the petiole is bent downwards at its
intumescence ; and in a few seconds
more the remaining leaflets upon the
same petiole fold their subleaflets in
pairs, from the base towards the point
of the leaflet.

If a subleaflet be burnt, instead of
being cut or pinched, the phenomena
above described occur more rapidly:
and after they have taken place, the
adjoining leaves upon the same branch
are bent down in succession, their leaf-
lets brought together, and their sub-
leaflets folded. If the plant be very
vigorous and lively, an impression

Fig. 2.

the Leaves of the Sensitive Plant

19

made upon one leaf affects the rest In succession. It is well
known that the stem, branches, flowers, and roots of tlie sensi-
tive plant have no motion. But M. Desfontaines observed
that, on touching the roots with sulphuric acid, the leaves
become folded ; and M. Dutrochet obtained a similar result on
burning either the flower or the stem.

If the plant be shaken, all the leaves are simultaneously
thrown down, and their leaflets folded. Mr. Lindsay attempted
to elucidate the action of the intumescence in raising and
depressing the petiole, in the following manner. He cut out
a portion from the upper or solar surface of the intumescence ;
after which he found that the petiole, upon recovering, rose
higher than before, {Fig. 3.) From another leaf he removed
the inferior portion of the intumescence : he found, upon this
injury, that the leaf declined more than before, and did not
again rise, (Fig. 4.) He noticed that a thin slice, pared from

Fig. 3.

Fig. 4,

Fig. 5,

either surface of the intumescence, has a like effect, but in a
less degree than a deep excision : and he found that when
similar experiments are made upon the intumescence of the
subpetiole, there is no essential difference in the result.

Thus Mr. Lindsay discovered, that the force which raises
the petiole exists in the lower part of the intumescence, and
that which depresses it, in the upper. He seems to have con-
sidered that the temporary excess of force in either part is
produced by an impulsion of the sap from the vessels of the
jdelding portion into those of the opposite portion.

BO Observations upon the Motion of

Dr. Dutrochet viewed these phenomena in some respects
more justly. He remarked, in addition to what Lindsay had
observed, that if, instead of the upper and under surface, the
lateral part of the intumescence be removed, the petiole be-
comes not raised or deflected, but inclined towards the side
on which it is injured {Fig. 5) ; and that if longitudinal slices
of the upper, or under, or lateral portions of the intumescence
are immersed in water, these separate slices immediately
become incurvated, that edge being concave which looks to-
wards the axis of the intumescence. From these facts Dutro-
chet inferred that the texture of the intumescence possesses
some modification of irritability; that, when excited, each
length of the intumescence (to use a very imperfect expression)
forcibly assumes an incurvated figure, like a curved spring
returning from a state of temporary extension ; that the petiole
is raised, when the action of the lower part of the intumescence
predominates ; is depressed, when the upper portion acts with
increased energy.

Mr. Burnett and myself had arrived at very similar conclu-
sions respecting the agency of the intumescence, before we
became acquainted with the inquiries of Lindsay and Dutrochet.

In Dutrochet's able researches, a more exact analysis, how-
ever, was obtained of the functions of this part. He discovered
that the cortex of the intumescence is the seat of its irritability:
for upon wholly removing the bark, so as to expose the ligneous
substance, the petiole was found to have been rendered motion-
less. Nevertheless, the intumescence, thus mutilated, remains
capable of transmitting an impression made upon its leaflets to
the leaves adjoining, Dutrochet further ascertained, that the
ligneous substance alone is fitted to convey the peculiar stimu-
lus, which spreads, from a point of the plant that has been
irritated, to the adjoining leaves.

The experiments already mentioned appear to explain the
mode in which the elevation and depression of the petiole, and
the divergence and approximation of the subpetioles are pro-
duced. It is probable that the contrivance for folding and
expanding the subleaflets is of a similar nature. Mr. Burnett
and myself conjectured that each subleaflet is raised by the
under part of the intumescence that exists at its base, and de«»

the Leaves of the Sensitive Plant,

81

pressed by some action of the upper portion of the same intu-
mescence. In trying the soundness of this hypothesis, we met
with the following evidence in its favour : —

Mr. Lindsay had observed, that at the moment when the
petiole is depressed, the under part of its intumescence assumes
a deeper colour. But the under part of the intumescence of
the petiole is the portion which is shortened during its depres-
sion, and which is overcome on this occasion by the superior
force of the upper portion.

Now it is to be remarked that in the subleafiets the upper
part of the little intumescence belonging to each corresponds,
in one respect alluded to, with the lower portion of the intu-
mescence of the petiole ; it is the portion shortened when the
leaf is folded. And we found, upon examination, that it like-
wise distinctly changes colour at the moment when the sub-
leaflet rises, while the under surface of the intumescence of the
subleaflet does not change its hue.

In pursuing this inquiry, another point of correspondence
between the mechanism which depresses the petiole, and that
which raises the subleaflets, was stated, which has yet additional
interest.

When the plant is not in its most lively state, the under sur-
face of the intumescence of the subleaflet (6, Fig. 2,) and the
upper surface of the intumescence of the petiole (a, Fig. 6,)

Fig. 7.

/k

Fiff. 8.

may be pricked with a needle, without producing action.
But if the opposite surfaces, those namely, which change colour
and are shortened when the petiole is depressed and the
subleaflets folded, are touched with the point of the needle
these actions are instantaneously produced. Here the sub-

JULY — OCT. 1827. G

S8 Observations upon the Motion of

leaflet is most delicately sensible ; a slight touch with the
pomt of a needle upon the upper surface of the intume-
scence of the subleaflet (c, Fig. 1,) causes the single sub-
leaflet so stimulated to rise ; and in this manner all the sub-
leaflets upon one side of a leaflet may be raised, their fellows
remaining expanded : if the touch be something sharper, the
fellow subleaflet rises at the same time ; if ruder still, the next
pair of leaflets fold directly afterwards, and the irritation then
proceeds entirely through the leaflet. But the most satisfactory
and curious results are obtained on stimulating the extension
surface of the intumescence of the petiole. The needle may
be applied to every point upon the upper or solar half of the
intumescence of the petiole (a, Fig. 6,) without producing any
visible effect ; but if the irritation be applied upon the under
half, (c^, Fig. 6,) either quite below or laterally, the petiole is
immediately depressed. The transition is abrupt from the sur-
face against which the needle may be made to prick, without
exciting action, to one which, when the needle reaches it, causes
the petiole to be instantaneously thrown down.
l^lt appears, therefore, that each intumescence has a surface
especially adapted to receive mechanical impressions ; which
surface is placed on the side of the intumescence opposite to
that, by which the consequent motion is produced. A curious
but vague analogy may be traced between these surfaces of the
sensitive plant and the organs of sense in animals.

We painted with a thick layer of lamp-black in oil the intu-
mescence of different petioles in different ways ; the upper sur-
face of one, the under surface of another, the side of a third.
The experiment was followed by no sensible effect. After a
few minutes the petioles, which had been thrown down by the
operation, rose again in each case, and fell again as readily as
before upon being stimulated afresh.

We tried what result would ensue upon slitting the intume-
scence of the petiole horizontally. The petiole, after this in-
jury, did not recover its usual direction ; the intumescence ap-
peared to have wholly lost its properties ; the leaf seemed to
depress the petiole by its weight alone, yet the leaflets ex-
panded, and exhibited their usual irritability, upon the depend-
ing stalk. The same effect, however, was observed, when the

the Leaves of the Sensitive Plant, 83

intumescence was divided by a longitudinal incision, made ver-
tically instead of horizontally.

I have already mentioned that Dutrochet discovered that the
ligneous fibre is the channel, along which an impression is
conveyed from one part to another. Mr. Burnett and myself
had made one or two experiments upon the course which the
irritation follows when spreading from leaflet to leaflet, where
several are placed upon the same petiole.

If the upper third of a petiole bearing four leaflets be di-
vided longitudinally, the irritability of the leaflets remains for
many days unimpaired ; upon cutting with scissors one snb-
leaflet after the plant has recovered itself, the irritation is ob-
served to descend the wounded leaflet, and then to pass to that
adjoining upon the same side of the petiole : afterwards the
petiole falls, but there the effect stops ; it does not extend to
the two other leaflets ; the direct route is cut through, and the
irritation seems to find no circuitous way, as might have been
expected, perhaps through the intumescence of the petiole back
again to the leaflets, on its summit. If on a petiole, bearing
four leaflets, a lateral incision be made, cutting the petiole half
through it at a point between the two leaflets which are situated
on one side, upon irritating either of the leaflets, between which
the incision has been made, it folds its subleaflets ; then the
two opposite leaflets fold their subleaflets ; and last of all, the
leaflet next adjoining that first irritated, but isolated from, it
by the incision, becomes folded.

In the few remarks which I have thus put together, I have
quoted Lindsay and Dutrochet only as far as their researches
anticipated my own : I leave unnoticed many experiments, in
several of which these authors are again found to have acci-
dentally coincided. The experiments to which I allude do
not, however, serve to illustrate the nature of the motion ex-
hibited by the sensitive plant, to the examination of which sub-
ject alone my attention was, in the present instance, directed,
in the expectation that it might throw light upon the obscure
and interesting subject of muscular action.

I remain, my dear Sir, Your's truly,

Herbert Mayo.
19, George Sireety Hanover Square,
August 29, 1827.

G ^

• . "A ^

84^ Mr. Faraday'5 Experiments on the Nature of

Experiments on the Nature of Labarraque^s disinfecting Soda
Liquid. By M. Faraday, F.R.S., Corn Mem. R. Acad.
Sciences, Paris, &c. &c.

1. The following experimental investigations relate to the
nature of that medicinal preparation which M. Labarraque has
lately introduced to the world, and named Chloride of oxide of
Sodium. They were occasioned by the accounts which were
given of this and other substances of similar power, to the
members of the Royal Institution, at two of their Friday even-
ing meetings * ; the value of the preparation, the uncertainty
of its nature, and the inaccuracy of its name, all urging the
inquiry.

2. In the first instance the inquiry was directed to the na-
ture of the action exerted by chlorine gas upon a solution of
carbonate of soda, questions having arisen in the minds of
many, whether it was or was not identical with the action ex-
erted by the same gas on a solution of the caustic alkali, and
whether carbonic acid was evolved during the operation or not.
Chlorine gas was therefore carefully prepared, and after being
washed was sent into a solution of carbonate of soda, in the
proportions directed by M. Labarraque ; i. e. 2800 grains of
crystallized carbonate of soda were dissolved in 1.28 pints of
water ; and being put into a Woulfe's apparatus, two-thirds of
the chlorine evolved from a mixture of 967 grains of salt with
750 grains of oxide of manganese, when acted upon by 967
grains of oil of vitriol, previously diluted with 750 grains of water,
were passed into it ; the remaining third being partly dissolved
in the washing water, and partly retained in the open space of
the retort and washing vessel. The operation was conducted
slowly, that as little muriatic acid as possible might be carried
over into the alkali. The common air ejected from the bottle
containing the solution was collected and examined; but from.
the beginning to the end of the operation not a particle of car-
bonic acid was disengaged from the solution, although the chlo-
rine was readily absorbed. Ultimately a liquid of a very pale

« See the last volume of this Journal, pp. 211, 460.

LabarraqueV Disinfecting Soda Liquid, 85

yellow colour was obtained, being the same as M. Labarraque's
soda liquor, and with which the investigations were made that
will hereafter be described.

3. An experiment was then instituted, in which the effect of
excess of chlorine,, upon a solution of carbonate of soda of the
same strength as the former, was rendered evident. The solu-
tion was put into two Woulfe's bottles, the chlorine well washed
and passed through, until ultimately it bubbled through both
portions without absorption of any appreciable quantity. As
soon as the common air was expelled, the absorption of the
chlorine was so complete in the first bottle, that no air or gas
of any kind passed into the second, a proof that carbonic acid
was not liberated in that stage of the experiment. Continuing
the introduction of the chlorine, the solution in the first bottle
gradually became yellow, the gas not being yet visible by its
colour in the atmosphere above the solution, although chlorine
could be detected there by litmus paper. Up to this time no car-
bonic acid gas had been evolved ; but the first alkaline solution
soon acquired a brighter colour, and now carbonic acid gas
began to separate from all parts of it, and passing over into the
second bottle, carried a little chlorine with it. The soda solu-
tion in the first bottle still continued to absorb chlorine, whilst
the evolution of carbonic acid increased, and the colour became
heightened. After some time the evolution of carbonic acid
diminished, smaller quantities of the chlorine were absorbed
by the solution, and the rest passing into the atmosphere in the
bottle, went from thence into the second vessel, and there
caused the same series of changes and actions that had occurred
in the first. The solution in the first bottle was now of a
bright chlorine yellow colour, and the gas bubbled up through
it as it would through saturated water.

4. When the chlorine had saturated the soda solution in the
second bottle, and an excess of gas sufficient to fill several large
jars had been passed through the whole apparatus, the latter
was dismounted, the solutions put into bottles and distinguished
as the saturated solutions of carbonated soda ; they were of a
bright greenish-yellow colour, and had an insupportable odour
of chlorine.

5. The saturated solution (4) was then examined as to the

86 Mr. Faraday's Experiments on the Nature of

change which had been occasioned by the action of the chlo-
rine. It bleached powerfully, and apparently contained no
carbonated alkali : but when a glass rod was dipped into it
and dried in a warm current of air, the saline matter left, when
applied to moistened turmeric paper, reddened it considerably
at first, and then bleached it ; and this piece of paper being
dried and afterwards moistened upon the bleached part, gave
indications of alkali to fresh turmeric paper.

6. A portion of the saturated solution (4) being warmed, in-
stantly evolved chlorine gas, then assumed a dingy appearance,
and ultimately became nearly colourless ; after which it had an
astringent and saline taste. Being evaporated to dryness at a
very moderate temperature, it left a saline mass, consisting of
much common salt, a considerable quantity of chlorate of soda,
and a trace of carbonate of soda. This mixture had no bleach-
ing powers. The dingy appearance, assumed in the first in-
stance, was found to be occasioned by a little manganese which
had passed over into the solutions, notwithstanding the care
taken in evolving and washing the gas.

7. From these experiments it was evident that when chlorine
was passed in excess into a solution of carbonate of soda (3),
the carbonic acid was expelled, and the soda acted upon as if
it were caustic, a mixture of chloride of sodium and chlorate of
soda being produced ; with the exception of the small portion
of carbonate of soda which, it appears, may remain for some time
in the solution in contact with the excess of chlorine at com-
mon temperatureis, without undergoing this change. The quan-
tities of chloride of sodium and chlorate of soda were not ascer-
tained, no doubt being entertained that they were in the well-
known proportions Avhich occur when caustic soda is used.

8. The Labarraque's soda liquor which had been prepared
as described (2), was now examined relative to the part the
chlorine played in it, or the change the alkali had undergone,
and was soon found to be very difi'erent to that which has been
described, as indeed the experiments I had seen made by
Mr. Phillips* led me to expect. The solution had but little
odour of chlorine, its taste was at first sharp, saline, scarcely at

♦ See Vol L of this Journal, p. 461 ; and Phil. Mag. N. S., I. 376.

Labarraque's Disinfecting Soda Liquid. 82

all alkaline, but with a persisting astringent biting effect upoa
the tongue. When applied to turmeric paper, it first i^ddened
and then bleached it.

9. A portion of the solution (2) being boiled, gave out no
chlorine ; it seemed but little changed by the operation, having
the same peculiar taste, and nearly the same bleaching power
as before. This is a sufficient proof that the chlorine, though
in a state ready to bleach or disinfect, must not be considered
as in the ordinary state of solution, either in water or a saline
fluid ; for ebullition will freely carry off the chlorine under the
latter circumstances.

10. A portion evaporated on the sandbath rather hastily,
gave a dry saline mass, quite unlike that left by the saturated
solution already described (6) ; and which, when dissolved, had
the same astringent taste as before, and bleached solution of
indigo very powerfully : when compared with an equal portion of
the unevaporated solution, which had beeii placed in the mean
time in the dark, its bleaching power upon diluted sulphate of
indigo was 30, that of the former being 76. Another portion,
evaporated in a still more careful manner, gave a mass of damp
crystals, which, when dissolved, had the taste, smell, and bleach-
ing power of the original solution, with almost equal strength.

1 1. These experiments shewed sufficiently that the whole of
the chlorine had not acted upon the carbonate of soda to pro-
duce chloride of sodium, and chlorate of soda ; that much was
in a peculiar state of solution or union which enabled it to
withstand ebulUtion, and yet to act freely as a bleaching or dis-
infecting agent ; and that probably little or none had combined
with the sodium, or been converted into chloric acid. To put
these ideas to the test, two equal portions of the Labarraque
solution were taken ; one was put into a large tube, closed at
one extremity, diluted sulphuric acid was added till in excess,
and then air blown through the mixture by a long small open
tube, proceeding from the mouUi, for the purpose of carrying
off the chlorine ; the contents of the tube were then heated
nearly to the boihng point, air being continually passed through.
In this way all the chlorine which had combined with the car-
bonated alkali without decomposing it, was set free by the sul-
phuric acid, and carried off by the current of air and vapour,
whilst any which had acted chemically upon the alkali would.

88 Mr. Faraday'5 Experiments on the Nature of

after the action of the sulphuric acid, be contained in solution as
muriatic and chloric acids, and from the diluted s.tate of the
whole, would not be removed by the after-process, but remain
to be rendered evident by tests. The other portion being di-
luted, had sulphuric acid added also in excess, but no attempt
was made to remove the chlorine. Equal quantities of these
two portions in the same state of dilution were then examined
by nitrate of silver for the quantities of chlorine sensible in them,
and it was found that the latter portion, or that which retained
the whole of the chlorine thrown into it, contained above sixty
times as much as the former.

12. Now although it may be supposed that in the former
portion that part of the chlorine, which, in acting energetically,
had produced chloric acid, could not be detected by the nitrate
of silver, yet more than a sixth of the small portion which re-
mains cannot be thus hidden ; and even that quantity is dimi-
nished by the sulphuric acid present in excess, which tends to
make the chlorine in the chlorate sensible to nitrate of silver :
so that the experiment shews that nearly 59 parts out of 60 of
the chlorine in M. Labarraque's liquid are in a state of weak
combination with the carbonated alkali, and may be separated
by acids in its original condition ; that this quantity is probably
wholly available in the liquid when used as a bleaching or disin-
fecting agent ; that little, if any, of the chlorine forms chloride
of sodium and chlorate of soda with the alkali of the solution ;
and that the portion of chlorine used in preparing the sub-
stance which is brought into an inactive state, is almost insen-
sible in quantity.

13. The peculiar nature of this compound or solution, with
the results Mr. Phillips had shewn me (8), obtained by evapo-
ration of a similar preparation to dryness, induced me to try the
effects of slow evaporation, crystallization, heat, and air upon it.
In the first place five equal portions of the solution prepared
by myself were measured out : two were put into stoppered
bottles, two were put into basins and covered over with bibulous
paper, and one was put into a basin which was left open ; all
were set aside in an obscure place, and remained from July
16th to August 28th. Being then examined, the portions in
the basins were found crystallized and dry ; the crystals were
large and flat; striated and imperfect, re&embling those formed

Labarraque's Disinfecting Soda Liquid. 89

in a similar way from carbonate of soda. They were not small
and aciciilar, were nearly alike in the three basins, and had
effloresced only on a few minute points. A part of one portion,
when dissolved, gave a solution, having an alkaline taste, with-
out any of the pungency of Labarraque's liquid ; and which,
when tested by turmeric paper, reddened, but did not bleach it.

14. One of these portions that had effloresced least was
selected, and being dissolved, was compared in bleaching power
upon diluted sulphate of indigo, with one of the portions of solu-
tion that had been preserved in bottles. The former had
scarcely any visible effect, though sulphuric acid was added to
assist the action ; a single measure of the indigo liquor coloured
the solution permanently blue, whereas seventy-seven such
measures were bleached by the portion from the bottle. Hence
the process of slow crystallization had either almost entirely
expelled the chlorine, or else had caused it to react upon the
alkali, and by entering into strong chemical combination as
chloride and chlorate, had rendered it inert as a bleaching or
disinfecting agent.

15. From the appearance of the crystals there was no reason
to expect the latter effect ; but to put the question to the proof,
one of the evaporated portions, and one of the fluid portions
contained in the bottles, were acted upon by sulphuric acid,
heat, and a current of air, in the manner already described (11),
to separate the chlorine that had not combined as chloride or
chlorate. They were then compared with an equal portion of
the solution, which retained all its chlorine, nitrate of silver being
used as before : the quantity of chloride indicated for the latter
portion was 60 parts ; whilst that of the fluid portion deprived
of as much free chlorine as could be, by sulphuric acid and
blowing, was 6 parts ; and for the evaporated and crystallized
portion, similarly cleared of free chlorine, only 1.5 parts.

16. This result, as compared with the former experiment of
a similar kind (11), shewed, that though reaction of the chlo-
rine on the carbonate had taken place in the evaporated portion,
it was only to a very slight extent, since the chlorine was
almost as much separated from it by the process altogether, as
it had been from the recent preparation by sulphuric acid,
blowing, and heat The experiment shewed also that there

00 Mr. Faraday'5 Experiments on the Nature of

was a gradual reaction of the chlorine and alkali in the fluid
preparation, proceeding to a greater extent than in the evapo-
rated portion ; for chlorine, equal to five parts, was found by the
nitrate of silver to remain. Hence this preparation is one
which deteriorates even in the small space of forty-three days.
Whether the effect will proceed to any great extent, prolonged
experiments only can shew.

17. From an experiment made upon larger quantities of the
Labarraque liquor, it would appear that the force of crystalliza-
tion alone is sufficient to exclude the chlorine. A quantity
was put into an evaporating basin, and left covered over with
paper from July 16th to August 28th. Being then examined,
a few large crystals were found covered over with a dense
solution ; the whole had the innocuous odour of Labarraque's
fluid, and the fluid the usual acrid, biting taste. The crystals
being separated, one of the largest and most perfect was chosen,
and being well wiped on the exterior, and pressed between folds
of bibulous paper, was rubbed down in water, so as to make a
saturated solution. This had no astringent taste like that of
Labarraque's fluid, or the mother-liquor, but one purely alka-
line ; and when applied to turmeric paper, reddened, but did
not bleach it. Equal portions of this saturated solution and
of the mother-liquor were then compared in bleaching power,
acid being added to the former to assist the effect : it was found,
notwithstanding that portions of mother-liquor must have
adhered to the crystal, that its solution had not ^th part the
power of the mother-liquor. This, in conjunction with the
other experiments, is a striking instance of the manner in which
the carbonate of soda acts, as a simple substance, with the
chlorine in the solution. The crystal itself had never been in
contact with the air : but whether it should be considered as
the excess of carbonate of soda only which crystallized ; or
whether it is essential to the formation of these crystals that
chlorine should simultaneously be given off into the air; or
what would take place, if the water were abstracted without the
evolution of chlorine, I have not determined.

18. Notwithstanding the perfect manner in which the chlo-
rine may be thus separated by crystallization and slow evapo-
ration to dryness, yet it is certain that by quick evaporaticm a

Labarraque'* Disinfecting Soda Liquid. 91

substance apparently quite dry may be obtained, which yet
possesses strong bleaching power. In one experiment, where,
of two equal portions, one had been evaporated in the course
of twenty-four hours to dryness upon the warm part of a sand-
bath, when compared with the former, it had not lost more
than one- third of its bleaching power.

19. With the desire of knowing what effect carbonic acid
would have on Labarraque's fluid, and whether it possessed
in a greater or smaller degree the power of ordinary acids
to expel the chlorine, portions of the solution were put into
two Woulfe's bottles, and a current of carbonic acid gas passed
through them. The gas was obtained from sulphuric acid
and whitening in a soda-water apparatus, and was well weished
in water. The stream of gas brought away small portions
of chlorine with it, but they were not sensible to the smell,
and could only be detected by putting litmus paper into
the current. An immense quantity of gas, equal to nearly
1300 times the volume of the fluid, was sent through ; but yet
very little chlorine was removed, and the bleaching powers of
the fluid were but little diminished, though it no longer appeared
alkaline to turmeric paper. Air was then passed through the
solution in large quantity ; it also removed chlorine, but appa-
rently not quite so much as carbonic acid.

20. One other experiment was made upon the degree in
which the carbonate of soda in Labarraque's liquor resisted
decomposition by the chlorine, even at high temperature. Two
equal portions of the fluid were taken, and one of them boiled
rapidly for fifl:een minutes ; both were then acted upon by
sulphuric acid, blowing, and heat, as described (11), and the
two were then tested by nitrate of silver, to ascertain the quan-
tity of chlorine remaining : it was nearly three times as much
m the boiled as in the unboiled portion ; and by comparing
this with the results before obtained (11), it will be seen that,
after boiling for a quarter of an hour, not more than a twentieth
part of the chlorine had acted upon the alkali, to form chbride
and chlorate.

21. It would seem as if I were unacquainted with Dr. Gran-
ville's paper upon this subject, published in the last volume of
this Journal, p. 371, were I to close my remarks without taking

9B Hieroglyphical Fragments.

any notice of it. Unfortunately, Dr. Granville has mistaken
M. Labarraque's direction, and by passing chlorine, to *' com-
plete saturation," through the carbonate, instead of using the
quantities directed, has failed in obtaining Labarraque's really
curious and very important liquid ; to which, in consequence,
not one of his observations or experiments applies, although
the latter are quite correct in themselves.

Royal Institution^ Sept. 3, 1827.

Hieroglyphical Fragments ; with some RemarJcs on English
Grammar. In a Letter to the Baron William Von Hum-
boldt. By a Correspondent.

My dear Sir,

I am happy to tell you that our prospects of new documents
from Egypt are very rapidly increasing: Mr. Burton has had
the good fortune to discover at length, in a mosque, the triple
inscription for which he has been some years in search ; and he
has been negociating with the Pacha for its removal. From its
magnitude and state of preservation, there is every reason to
believe that it will rival the pillar of Rosetta in its importance,
and I sincerely hope that it will tend to check the wildness of
conjecture, which has been rioting without bounds in the regions
of Egyptian literature. Mr. Tattam is printing a Coptic
grammar, and I am preparing an Appendix, which is to contain
the rudiments of an Enchorial Lexicon : I ardently wish that
Mr. Burton's inscriptions may come to my assistance before 1
complete it. I have received nothing from France or from
Germany for these four years past : even what is published
seems by some fatality to have been withheld from me;
and the booksellers send no answers to my commissions. I
trust your brother will not forget his kind promise to think of
me at Berlin.

I have to thank him and you for your obliging present of
your Letter to Abel Remusat on the Genius of the Chinese
Language, which has greatly interested me : the best return
that I can make will be to give you some remarks which have
occurred to me on the language of hieroglyphics in general,

Hieroghjphical Fragments, 93

and on the character of the English language, which seems to
approach, in its simplicity, as you have yourself observed, to
the natural structure of the oldest languages, immediately
related to the hieroglyphical form of representation. I fear,
however, that I must apologize to you for the want of method
with which I shall be obliged at present to throw my fragments
together: but it may be allowable to make some difference
between a letter and a finished essay.

Hieroglyphics, in their primitive form, are scarcely to be
considered in any case as simply a mode of expressing an oral
language : they may be a direct and independent representation
of our thoughts, that is, of recollections, or sentiments, or
intentions, collateral to the representation of the same thoughts
by the language of sounds. We find, in many of the Egyptian
monuments, a double expression of the same sense : first, a
simple picture, for instance, of a votary presenting a vase to a
sitting deity ; each characterized by some peculiarity of form,
and each distinguished also by a name written over him ; and
this may be called a pure hieroglyphical representation, though
it scarcely amounts to a language, any more than the look of
love is a language of a lover. But we universally find that
the tablet is accompanied by a greater variety of characters
which certainly do constitute a language, although we know
little or nothing of the sounds of that language ; but its import
is, that ** such a king offers a vase to the deity;" and on the
other side, that " the deity grants to the king health and
strength, and beauty and riches, and dominion and power." It
is common to see, in these inscriptions, a number of characters
introduced, which are evidently identical with some of those
in the tablets: and however some of them may occasion-
ally have been employed phonetically, there can be no question
of the nature of the changes which their employment must
have gone through before they assumed the character of sounds :
but this is altogether a separate consideration, and foreign to
the present purpose.

Now it is obvious that objects, delineated with the intention
of representing the originals to the eye by their form, must
necessarily be nouns substantive ; and that the picture, con-
taining no verb whatever, can scarcely be said to constitute

941 Hieroglyphical Fragments.

either a positive or a negative assertion. At the same time, it
must be allowed that a picture of King George the Fourth's
coronation, with the date 19 July 1821, could scarcely be con-
sidered otherwise than as asserting a historical truth ; and if
any emblem of Truth were attached to it, or if it were deposited
among the records of other historical facts, it would be equiva-
lent to the expression, " George IV. crowned in July 1821,"
which scarcely wants the verb was to convert it into a positive
assertion of a fact.

Strictly speaking, however, there seems to be no direct mode
of supplying the want of the verb is or was iii pure hierogly-
phical writing; and if any such sign was employed in the
Egyptian or the old Chinese hieroglyphics, its introduction
must have been arbitrary or conventional ; like the employment
of a postulate in mathematics. Every other part of a language
appears capable of being reduced, with more or less circumlo-
cution, to the form of a noun substantive ; and the English
language appears to approach to the Chinese in the facility
with which all the forms of grammar may be shaken off.

There is, however, often occasion, in such cases, for a certain
degree of metaphor approaching to poetical latitude ; and hence
it may happen that the least literary nations are sometimes the
most poetical. It is, in fact, impossible to exclude metaphor
altogether from the most prosaic language ; and it is frequently
difficult to say where metaphor ends and strict logical prose
begins j but by degrees the metaphor drops, and the simple
figurative sense is retained. Thus we may say liquid ruby
with the same exact meaning as crimson wine; and yet ruby
would never be called an adjective, though employed merely to
express the colour : in coral lips, however, the coral, first used
metaphorically, is converted by habit into an adjective, and the
expression is considered as synonymous with labri corallini.

The general custom in English is to place the figurative
substantive, used as an adjective by comparison, or by abstrac-
tion, before the name which retains its proper sense : thus a
chestnut horse is a chestnut like or chestnut coloured horse ;
a horse chestnut is a coarse kind of chestnut: and in this
manner we are enabled to use almost every English noun sub-
stantive as an adjective, by an ellipsis of the word like, which.

Hieroglyphical Fragments. 95

if inserted entire or abridged, would make a real adjective of
the word, as yf&rlike, friendly. But this omission of the termi-
nation, like other figures of speech, is easily forgotten in the ordi-
nary forms of language ; and the Germans, as well as the English^
make use of almost all their substantives in the place of adjec-
tives, though they are more in the habit of continuing them
into single long words. When, however, the substantives are so
used, they generally become by abstraction real adjectives : for
we seldom think of a chestnut, in speaking of the colour of a
horse ; but the idea of a light brown coat, with an ugly pale-
red mane and tail, and a fidgety temper, is very likely to occur
to us : arid in a horse chestnut the idea of a horse is out of the
question ; we only think of a coarse fruit which a man cannot
eat : so that the true sense, in both these instances, is that of a
quality ; but coral lips and ivory hands are rather elliptical
expressions, composed of two substantives, which might fairly
be represented hieroglyphically by the assistance of a branch
6f coral and an elephant's tusk. But to describe an abstract
quality by any hieroglyphic character, representative of form
only, would be generally impossible : colours might be imitated,
if we supposed coloured figures to be employed ; but other
simple ideas, such as those of sound or touch, could never be
immediately presented to the eye ; and some circuitous inven-
tion would always be required for their representation.

Home Tooke has shewn, with considerable felicity of illus-
tration, that all the parts of speech may be resolved into the
noun and the verb ; but he has not pointed out so clearly that
every verb may be resolved into a noun and the single primi-
tive verb is or was, which, in this sense, may be said to be the
only essential verb in any language ; as we find, indeed, in the
Coptic, that almost every noun becomes a verb, either by the
addition of pe, or sometimes even without it. Thus, the morn-
ing BLUSHES is synonymous with the morning is red ; he loves
justice, with he is a lover of justice ; and / am an Englishman,
with the person now speaking is an Englishman. But this must
be understood of is, was, or will be, in all its tenses ; the idea
of time, if expressed, being an essential part of the verbal sense.

I confess that some of these reflections have occurred to me
in looking over a very singular work, which I had the curiosity

SS. Hieroglyphical Fragments.

to take up, in order to see what kind of information could be
possessed by a person notoriously and professedly ignorant of
the origin and relations of the language which he attempts to
teach ; and, in short, what kind of light could be diffused by
an apostle of darkness. Blunders, and some of them ridiculous
enough, must, of course, be found in the works of such a person,
but most of them are such as every schoolboy might correct ;
and there really is so much of sagacity in some of Mr. Cob-
bett's remarks on the errors of others, that they well deserve the
attention of such as are ambitious to write or speak with perfect
accuracy.

I shall not attempt to enter into a regular criticism of this
Grammar ; I shall merely make a few miscellaneous observa-
tions, as they have occurred to me in reading it, several of
which would be equally applicable to the best of the existing
works of a similar nature.

In Letter III we are told that long and shorty though adjec-
tives, do not express qualities, but merely dimension or dura-
tion ; from a singular misconception of the proper sense of the
word quality. We find, in Letter IV, the rule given by most
grammarians, though not by all, that the article A becomes
AN, when it is followed by any word beginning with a vowel ;
but it is surely more natural to follow the sound than the spell-
ing, and, as we should never think of saying an youthful bride,
it seems equally incorrect to say an useful piece of furniture ;
for the initial sound is precisely the same. In the same manner
A unit and a European^ seems to sound more agreeable than
AN ; and the best speakers appear to adopt this custom.

Letter VIII gives us a rule for doubling the last letter of a
verb in the participle if an accent is on the last syllable : but it
should be observed that the L is doubled, whether accented or
not, as in caballing, travelled^ levelled, cavilled, controlled.
The same letter contains a '^ List of verbs, which, by some
persons, are erroneously deemed irregular," and which have
been so deemed from the time of our German and Saxon an-
cestors, though Mr. Cobbett thinks it would be more philoso-
phical to conjugate them regularly. Thus we may see at once
ihsX freeze may as well give us frozen, asfrieren gives the Ger-
mans gefroren ; that hang may make hung or hanged, accord-

Hieroglyphical Fragments. 97

ing to its sense, as in German we have hienge from hangen, and
hdngte from hangen, to execute. For sling and slungy we have
authority in schlingen, gesc/dungen, for spring and sprung in
springen and gesprungen; for swollen, swam or swum, and
swung, in geschwollen, geschwommen, and geschwungen. And
it is quite clear from these examples that '^ the bad practice
of abbreviating, or shortening," has nothing to do with the
matter.

In Letter XIV we have a very distinct examination of a rule
in punctuation which has been commonly adopted by good
printers, without so distinct a description of its foundation.
*' Commas are made use of, when phrases, that is to say * por-
tions' of words, are * throwed^' into a sentence, and which are
not absolutely necessary to assist in its grammatical construc-
tion." In a word, two commas are very nearly equivalent to
the old fashioned parenthesis. Again, *' the apostrophe ought to
be called the mark not of ehsion, but of laziness and vulgarity;'^
a remark made in truly classical taste, which might have been
extended with perfect propriety to the subject of the next para-
praph, the Hyphen, the insertion of which is, to make it uncer-^
tain whether the words united by it are one word or two. He
goes on admirably in the next page. ^' Notes, like parentheses,
are interrupters, and much more troublesome interrupters,
because they generally tell a much longer story. The em-
ploying of them arises, in almost all cases, from confusion in
the mind of the writer. He finds the matter too much for him.
He has not the talent to work it all up into one lucid whole ;

and, therefore, he puts part of it into Notes" " Instead of

the word and, you often see people put Sf. For what reason I
should like to know. But to this Sf is sometimes added a c ;
thus, 8fc. And is, in Latin, et, and c is the first letter of the
Latin word caetera, which means the like, or so on. This
abbreviation of a foreign word is a most convenient thing for
such writers as have too much indolence or too httle sense to
say fully and clearly what they ought to say. If you mean to
say and the like, or, and so on, why not say it ? . . . The abbrevi-
ation is very frequently made use of without the writer having
any idea of its import." But it is surely a mischievous maxim,
never to " think of mending what you write. Let it go. No

JULY— OCT. 1827. H

^8 'Hieroglyphical Fragments.

patching ; no after painting.'' On the other hand he is right
in protesting *' against the use of what, by some, is called the
dash. Who is to know what is intended by the use of these
dashes ? .... It is a cover for ignorance as to the use of points ;
and it can answer no other purpose."

In Letter XV, there is a singular conceit with regard to the
keeping up a distinction between a and an, where it is insisted
that we must not say " a dog, cat, owl, and sparrow/' because
owl requires an ; " and that it should be, a dog, a cat, an owl,
tind a sparrow ;" which is certainly better, and would be so, even
if there were no owl in the question.

Letter XVII. The criticism on Milton's *' than whom none
higher sat," is perfectly correct. TAaw is never a preposition,
and is simply a variation from the older then, both in English
femd in German. John is better than James means simply
John is good first, then James : £r is eher or e'er. Who would
sound awkwardly, but would be more grammatical.

Letter XIX gives a definition of the ellipsis, which would be
^ lesson to Apollonius himself: the compasses, it seems, '' do
iiot take their sweep all round, but leave out parts of the area
or surface." The objection to Blackstone's language is very
questionable. "The \ery scheme and model was settled,"
may, perhaps, be defended, because scheme and model are con-
sidered as one thing, the words being intended to illustrate each
other, but not to point out different attributes of the adminis-
tration of justice ; and both words may be admitted, as a col-
lective term, to govern a singular rather than a plural verb.
It seems also to be an error to make with a conjunction rather
than a preposition, and to say " The bag, with the guineas and
dollars in it were stolen," or " zeal, with discretion, do much."
^ I expected to have seen," is justly noticed as a common
ferror for *^ I expected to see." The meaning of an active verb
is erroneously confounded with that of a transitive verb, in th6
temarks on the word elope, which m^ans to go off, or to run
bff, and we should naturally say was gone off, but had run off.
The nature of the subjunctive mood is dismissed in the same
Letter without better success than has been obtained by former
grammarians. An essay was published about thirty years ago
in a periodical-work, which brings the subject into a small com-

Hieroglyphical Fragments. ^99

; suggesting that the subjunctive mood ought always to be
considered as a conditional future. The exami)les given are,
^ If the Elbe is now open, we shall soon have the ihails, and
then, if there be any news from the army, I will send it you im-
mediately." '^ If Catiline was generous, it was in order to
serve his ambition." The subjunctive past, if I were, becomes
present, by being the future of the past ; going back to the time
when the present was future, and therefore contingent ; and
this conditional sense involves no difficulty, except when a mis-
taken adherence to the fancied rules of grammar forces it in
where it has no business : thus the rules of some grammarians
would lead us to say, if Catiline were ambitious ; which is to-
tally contrary to the true sense of the subjunctive. Mr. Cob-
bett seems to have some such distinctions in view when he says
that " if has nothing at all to do with the government of the
verb. It is the sense which governs." By this he means that
if does not require a subjunctive unless is relates to a future
contingency. He is right in saying '* Though her chastity
is becoming, it gives her no claim to praise" : but most decid-
Mly wrong in adding ^* she would be criminal if she was not
chaste" ; for was is hei'e used as relating to the present cir-
cumstances, which are the future of the past, and therefore re-r
quire the subjunctive were to denote the condition intended.
He has, however, done signal justice to the cause of this injured
verb, by introducing it for was, in his sixth lesson, where he says
it should have been '* Your Lordship were apprized of every
important circumstance."

Such errors as this, however, are easily corrected, and many
of the acute remarks which have been here copied are well
worthy the attention of practical grammarians ; at the same
time enough has been said, without any disparagement of
Cobbett's talents, to show that a man cannot be well qualified
to teach that which he has not had the means of properly learn-
ing. For although the English language appears at first sight
to be extremely simple and philosophical in its structure, it
has, in fact, been derived from a variety of heterogeneous
sources ; it has undergone a variety of vicissitudes, and has
served for the expression of a multiplicity of discussions on the
most refined subjeeia in literature and history and science, for

H 2

100 Dr. Mac CuUoch's Essay on the

the feelings of oratory, and the passions of })oetry, and it has been
worn away by degrees, as the crystal in the stream is worn to a
pebble, till it has returned to a simplicity which wears the aspect
of the immediate offspring of the Chinese or Egyptian or Mexi-
can Hieroglyphics. But with all this, it has still some spots, some
idioms, which invariable custom obliges us to retain ; and which
can only be distinguished from corruptions and vulgarisms by
tracing their history through the different stages of its progress,
including, of necessity, the corresponding idioms in the parent
languages out of which it has arisen.

Believe me always, my dear Sir,

Your's very sincerely,

* # * *

Malaria : an Essay on the Production and Propagation of
this Poison, and of the Nature and Localities of the Places
by which it is produced, with an Enumeration of the Dis-
eases caused by it, and of the Means of diminishing and
preventing them, both at Home and in the Naval and
Military Service. By J. Mac Culloch, M.D., F.R.S.,
&c. &c. Longman and Co. 1827.

Though we have given a place in our Journal to two
articles on Malaria from Dr. Mac Culloch, we have thought it
expedient to take some notice of his book under the form of
a review ; particularly as some matters have come under
our cognizance, which may add some illustrations to this
subject where the author appears to have been in a state of
deficient information, or to have shunned the question for
reasons which appear to us somewhat over refined.

We allude principally here to the localities and the facts,
as they are now before us ; circumstances and events which
seem to us of the greatest importance, as enforcing the value
of the details which he has collected, and as holding out
warnings to the people respecting the preservation of their
healths, in addition to those which the work before us has
given in describing the soils or characters of ground in
England from which this destructive poison is generated.
And before we proceed to the analysis of his book, we shall
state what those are, or at least a few of them., while won-
dering that he should have overlooked them, or regretting
that any fancies should have prevented him from stating
what would have been of so much utility.

Production and Propagation of Malaria. 101

It 18 notorious that, m the last autumn, the remittent
fevers in various parts of the country amounted to a species
of pestilence, such as has scarcely been known in England
from this cause, or we might almost indeed say, from any
other disease since the days of Sydenham. Wherever ague
had ever existed, or even been supposed possible, in those
places was this fever found : so that in all the well-known
tracts in Lincolnshire, Norfolk, Suffolk, Kent, Essex, Sussex,
Hampshire, and so forth, there was scarcely a house without
one or more inhabitants under fever, while the event, as might
be suspected, was a considerable mortality. In the parish
of Marston, in Lincolnshire, for example, it amounted to 25 in
300 inhabitants ; in some other places, it reached one in
sixteen, one in thirteen, one in nine. And so extensive was
its range, that even Hastings did not escape ; while it should
be almost superfluous to say that every other town on the
sea-coast was so much infested by it, that they who resorted
to them for bathing, as usual, found themselves most awk-
wardly situated, and also suffered in considerable num-
bers.

To come nearer home, and to what must interest us of the
metropolis more, the same fevers were extremely abundant
in various parts of the outskirts of London, as also in the
villages or towns which are connected with it, within a range
of from six to ten miles. Not to enumerate all these, this
was the case throughout the range of streets or houses which
extends from Buckingham Gate to Chelsea ; in which long
line, it is said, that almost every house had a patient or more
under this fever : though, as the author has truly observed,
these were mistaken for typhus, or at least thus misnamed.
Thus it was also about Vauxhall and Lambeth ; and to a
great extent among all that scattered mixture of town and
country which follows from Whitechapel, from Bishopsgate,
and so forth, and very particularly along Ratcliffe Highway,
and so on, to an indefinite range along the river, not only on
this side but on the opposite one, so as to include Rother-
hithe, and then proceeding onward to Deptford, Greenwich,
Woolwich, Plumstead, so as to carry us beyond the boundary
which we proposed to notice.

And in addition to the towns or villages which we have
just named, we may enumerate Lewisham, in which we knew
one house in which there were nine patients under this fever,
which proved mortal to one. Dulwich, especially subject
to this disorder, Fulham, Ealing, and the several other Vil-
lages along the Thames, as far as Chertsey ; and even Rich-

ICQ? Dr. Mac Culloch's Essay 07i the

mond, where, as at Lewisham, there was one house known
to us. inasmuch as being intimate friends, where ten indivi-
duals at one time were suffering under this disease.

We must not prolong this enumeration, since we might
easily occupy a dozen of our pages with similar details, rang-
ing, in fact, all over England ; but we must still observe, that
whatever was the pestilence last year, it promises to be much
greater in the present one. This is easily judged from the
manner in which the season has set in ; but still more decid-
edly from the extraordinary prevalence of ague in the spring ;
since that which is intermittent fever then, will be remittent
in the autumn, or rather, as the author has justly remarked,
there will scarcely be a definite season of vernal intermittent,
but the remittent will commence immediately, increasing in
extent and severity as the summer advances, and promising
to become, in the autumn, the greatest season of disease that
England has known for this century.

As an example of this, it must suffice to enumerate two or
three facts, while these are as satisfactory for our purpose as
a thousand would be. The most general of these is, that
ague is at this moment extremely abundant where it was for-
merly so little known as not to be noticed, and that where
single cases used to occur, there are now hundreds. Thus
has it prevailed at Fulham and Ealing, and in the out-
skirts of London, and even in the town itself; and thus does
it so prevail at Greenwich, Deptford, and in the associated
vicinity, that a medical friend informs us, that it comprises
more than two-thirds of his entire practice, which is very
extensive ; whereas a few years ago he had rarely a patient
in a year. Thus also in the Military Hospital at Woolwich,
there were in the spring three hundred patients with this
disease ; while in former times, we are assured, that an ague
was scarcely known once in five or six years.

These are a few of the facts within our knowledge, but not
one in a thousand, which evince the necessity of the publica-
.tion before us ; a book which seems to have been singularly
well-timed, in as far as its purpose is, by a dissection of the
sources of malaria, to diminish the ravages of both these
kinds of fevers. And in this view we consider it a work of
very considerable utility, inasmuch as it points out all the
needful circumstances, as to prevention, in great detail; while
these seemed particularly called for in England, from the
entire and not less singular neglect which this subject has
jBxperienced, not only from the people at large, but from the
medical profession. Beyond this, all that we need say of

Producti(m and Propagatioit of Malaria. 10^

the character of the work is, that it contains the only regular
and complete attempt at the natural history of Malaria that
has been executed ; since the several foreign writings on this
subject are partial, or imperfect, or local in their investi-
gations ; and having said thus much, we shall proceed to give
a brief analysis of its form and matter. And this analysis
may be truly brief, without inconvenience ; since the two
Essays from the pen of the author, to which we have given
a place in our Journal, will supersede the necessity of mak-
ing that useful and practical abstract which we should othei;-
wise have felt ourselves bound to give.

To pass over an introductory chapter of the usual neces^
sity, the author commences by pointing out the several dis-
orders, in a general way, which are produced by malaria, fop
the purpose of proving the sources of this poison ; and as we
are of those who take the facts as already proved, we need
not notice it further.

The third chapter details the characters of those soils or
situations which are most commonly or generally admitted to
produce this poison: and though it contains some facts not
very universally known, we shall also pass it over as of less
moment than that which follows.

This is the fourth chapter, containing the details of the
circumstances producing malaria, which have been eithei*
.denied or overlooked ; and it is one of the most important
practical chapters in the book, inasmuch as it is to the po-
pular ignorance of these that we must attribute a large pro-
portion of the cases of fever occurring in common life.
These, therefore, vve shall mark briefly ; and even the briefest
notice will be of use in the way of precaution, while we
must refer to the book itself for those proofs of the truth of
the several views which we could not take room to give.
Generally, however, we may state this leading argument of
,the author, because it is brief, and, to us, appears satisfac-
.tory. : It is this : that as the quantity of the poison which
any person can inspire is necessarily small, and as this small
quantity can be produced by a small marshy spot as well as
a large one, it is the same, as to the production of disease,
whether the marsh is a foot square or a mile, provided the
exposure be complete : while also, any piece of ground where
vegetables decompose under the action of water, is virtually
a marsh, or must produce malaria.

. This enumeration, therefore, under that view, comprises,
.in addition to marshes, whether fresh or salt, all the cases
where water is present in such a manner as to act upon vege-
tables ; and the chief are the follp^ng.

104 Dr. Mac CiiUoch's Essay on the

It is shown, and by facts, that the rushy swamps of high
moorlands, however small the extent, do produce this dis-
ease ; and we must not here forget to name what, however,
belongs to the preceding chapter, woods and coppices, little
suspected in England, yet shown to be the cause of fevers in
Wales, and also in Sussex; very probably, every where else.
It is also shown that meadows and moist pastures, whether
in flat lands or on elevations, generate fevers ; and very par-
ticularly, should they have been affected by inundation or
unusual moisture, and if that should be followed by heat.
And while it is also specifically shown how, in all cases, it is
the produce of the drains or ditches required in meadow
lands, it is distinctly proved that, even without these, ma-
laria is produced, or that it is generated by the meadow or
moist pasture itself.

It is also shown that this poison is produced by rivers, by
all flat rivers at least, or those of which the progress is slow
and through meadow lands ; while this is pointed out as one
of the causes, especially, which is not suspected or not be-
lieved in England. And here we can add a fact to our
author's statement, which is decisive : this is the case of the
barracks at Morne Bruce, in Dominica, situated on a steep
and rocky hill, perfectly dry, and free from all other causes
of suspicion, while eternally subject to the most severe fevers.
And the cause is, a mountain stream, about 300 yards be-
low this building, in the valley, always covered by a mist
in the evenings, and ascertained, by direct experience, to be
the very cause of the diseases in question.

Our author also notices canals, mill-ponds, ornamental
waters, and all other pools and ponds, even to so small a
dimension as those formed in gravel-pits; pointing out those,
in particular, as common causes of fever about London, and
apparently much inclined to pass a very severe judgment on
the canal in St. James's Park, and also on the pond in St.
James's Square, while apparently restrained by his pruden-
tial reasons, which appear to us sufficiently misplaced, or, as
we should fairly call them, somewhat absurd. But as we
must not affront a writer whose papers we have admitted,
we shall say no more on this matter. In noticing drains, he
also speaks of moats and modern fortifications ; attempting
to show that the fevers so common in the sieges of ancient
castles were produced by their moats, and noticing the fami-
liar fact of the frequency of fevers in fortified towns. Lakes
also are pointed out as situations generating this poison : and
it is here especially noticed that if, in those and other cases,
malaria is produced by the vegetable growth and decompo-

Production and Propagation of Malaria, 105

sitlon, so is it the consequence of the exposure of the mud of
such receptacles of water ; a cause which is again treated of
at greater length in the subsequent chapter.

This chapter relates to what the author calls obscure and
disputed cases. We shall pass over these, which, as not
implying precautionary measures, are of the least interest,
and commence by noticing the case of vegetable putrefaction.
It is attempted to show, tnat the vegetable need not be living
to produce malaria, but that, even if utterly decomposed, its
elements, acting on water, can generate this poison. Among
the cases under this head, are flax and hemp ponds, common
sewers and drains, dunghills, and tide harbours ; and the
evidences under each are sufficient to make good the asser-
tion. But the most important of all, in our view at least,
is bilge-water : since our author has pretty clearly shown that
all the fevers of ships (excepting, of course, a few casual in-
stances of contagion) arise from this cause, and that if ships
were kept clean, fever or sickness would be nearly unknown
at sea. This we do indeed conceive one of the most import-
ant points in the work before us ; and if the author has re-
ferred to Sir Henry Baynton, as a stranger, we can quote
him, as a friend, that warrants for all that is here asserted,
and for far more ; since his collection of facts on this subject
is most important, and we think him almost culpable in not
having long ago given them to the public. If the Leviathan
was always the healthiest ship in the navy ; if she even left
the West Indies, after a long anchorage and service, with a
crew of 500 men, and not one sick, it is a case in the navy
which never occurred before, nor since, and which arose
entirely from the knowledge of this able and careful officer
respecting the subject that we are discussing.

A sixth chapter explains, under the head of revolutions in
the production of malaria, a variety of circumstances not
easily admitting of abridgment. The chief of these are, the
effects produced by drainages, and reversely, those which
arise from inundations or other incidental causes affecting
the state of the soil. But the most important view which it
contains is that which relates to the effect of embankment in
rivers, and to the geological changes produced by the distri-
bution of alluvia. As, however, we cannot well state this in
a small space, we shall pass to the chapter on the Propaga-
tion of Malaria.

This is the largest, and, as it strikes us, the most interest-
ing of the whole ; while the author has made it the depo-
sitory of a variety of remarks and recommendations on this

106 Dr. Mac Culloch's Essay on the

subject, very particularly as it relates to the army. If he is
correct, — and we see no reason to doubt it, from the nature
of the statements, — the ignorance of this subject, even among
the medical department of the army, has been most extraor-
dinary and moat unaccountable ; while if Walcheren is proof
enough of this, the writer before us has pointed out facts
enough to show that it was not a solitary case, while evidently
restrained by fear of some sort — we are almost inclined to
call it cowardice — from telling all that he might have told*
And we do think it wrong to retain or suppress that which
is important to the public safety, under a fear that the feel-
ings of individuals may be hurt ; since the business of a
writer is with justice and utility, and the security or welfare
of thousands is of infinitely greater moment than the comforts
of a few, and those also culpable.

Under this head, propagation, the author describes how
this poison is conveyed by the winds, while the facts add
much to the number and variety of the precautionary mea-
sures. And here also we find a speculation of no small
curiosity, respecting the East wind, attempting to prove that
wherever this is insalubrious or pernicious, it arises from its
being the vehicle of malaria ; while attempting also to prove
that this substance can be conveyed from Holland to the
coasts of England in that wind. We shall not pretend to
give an opinion on this subject ; and, since the author himself
has noticed it in the paper printedj in our present number,
we shall suffer our readers to form their own judgments
respecting it.

One also of the most curious facts mentioned in this chap^
ter, is the singular limitation of malaria ; and we must admi^
that the instance quoted as to the Chatham road is so re-
markable as to be almost incredible ; though, as we find that
all the people agree in it, we cannot pretend to say it is not
a fact. Indeed the facts of this nature, so familiar at Rome,
are fully as inexplicable ; so that all we can conclude is, that
we are ignorant of the philosophy of this subject : no very
great cause of surprise, unless it were proved that we could
explain every thing else which belongs to meteorology.

In the eighth chapter we have an explanation of the effects
of climate and seasons in the production of malaria ; and
.while we need not analyse the facts which it contains, we
may introduce in lieu of this, the explanations which its
statements afford as to that recent increase of the diseases
of malaria which we noticed at the commencement of this
^article. The last few years have been distinguished for an

Production, mid Propagation of Malaria, 107

uncommon prevalence of East winds, and to such a degree
indeed, that we can find no meteorological records at all to
be compared with the history of these years. And while the
history of the intermittent and remittent, in London at least,
from the time of Morton and Sydenham downwards, shows
that all its periods of such diseases have been periods of
Eiast winds, it is not difficult to see how it acts as to both
classes of marsh fever. To London, in particular, it is the
best conductor, propagating the malaria from all the moist
lands to the eastward. To the East coast, if our author's
theory is valid, it brings the malaria from Holland ; and,
moreover, as it forms our hottest summers, it causes our own
climate to approximate more to the southern ones, and thus
enables our lands to produce a greater quantity of malaria
than in ordinary summers.

To pass from the eighth chapter, the ninth is a partial
sketch of the geography of malaria ; a chapter for which the
author apologises, but which is nevertheless a very interest-
ing collection of facts on a subject where a volume is, doubt-
less, a desideratum. And it would require a volume; while,
in spite of our author's fears, we can really see no reason
why such a statistical account of health should not be drawn
up for England, when the utility of it is unquestionable. It
is true that people cannot abandon their homes or change
their residences, because their lots happen to be cast in an
insalubrious country. But it is not less important to know
what and where these dangers are ; because, though the
inhabitants may be compelled to abide, they can still correct
much of the evil by the various modes pointed out, or avoid
much of the hazard by resorting to the obvious precautions.
To be ignorant, is to be exposed to the full evil : to know
where it lies, is to know how and where to avoid it in nume-
rous ways ; since it will be found that by far the greater
number of diseases occurring, were not necessary or una-
voidable, but have been the result of ignorance as to the
precise fact or spot which did produce the effect in question.
And this we conceive to be the great use of the book before
us ; and that if ever it, or a code of rules founded on it,
shall become popular, or form a vade mecum, particularly
in the country, the effect will be to reduce most materially
the quantity of disease, and very particularly that which is
by far the most serious, the summer and autumnal fevers.
On this ground, we should be glad to see a geography of
malaria for England ; and we do hope that it will be under-
taken hy some person of sufficient industry, and of mor^

108 Dr. Mac CuUoch on Malaria,

courage than our author ; while we cannot doubt that who-
ever attempts it would at least find it a profitable specula-
tion. With these remarks we must pass over this chapter,
as we could take no statement from it which would serve
any useful purpose ; though, as far as it goes, it will form
a very useful guide to travellers on the continent of Europe,
or to those who, as emigrants, are in search of a residence
abroad.

The tenth chapter examines the inquiries which have been
instituted into the chemical nature of malaria, leaving the
question just where it was. In fact we, as chemists, do not
believe tnat this science is yet in possession of the means
required for analyses of this delicate nature ; but we see no
reason whatever why it should be despaired of, when che-
mistry has already, within a very few years, effected things
which seemed far more impracticable and hopeless.

The eleventh and last chapter contains an enumeration of
the diseases produced by malaria, presenting a most formid-
able list, and absolutely making us shudder in some of the
details which relate to the worst parts of France and Italy.
The representation here given of the average of life in these
districts is particularly striking ; while of the truth of all
the facts, we can speak from personal knowledge. Our
author has also noticed the effect of this poison on animals ;
showing that it is the cause of the noted epidemics in cattle,
and also of the rot in sheep. If he will look into Livy, he
will find a confirmation, which he appears to have passed by
when quoting that author for epidemic seasons : this being,
that in the same years in which epidemic '' pestilences" ap-
peared among the people, there was also a great mortality
among the cattle.

We do not know what his own profession will say of his
attempt, or rather proposal, to prove that the celebrated
disease of the nerves called Tic Douleureux is the produce of
malaria and a mode of intermittent fever ; nor how they will
receive his proposal to arrange Sciatica and Rheumatic pains,
with many other local diseases, under this head. But this is
not our affair : and as he has promised us two other volumes,
on all the diseases which are produced by malaria, including
these, we must wait with patience ; knowing at least that he
is a dealer in facts and not in hypotheses, and expecting,
that even if he should fail to establish his point, he will try
to do it, as he has been used to do in the other sciences
which he has attempted, through the road of facts and
evidence.

Mr. Lindley on a New Genus of Plants. 109

An Account of a new Genus of Plants called Reevesia. By
John Lindley, Esq., F.L.S., &c. &c.

In a collection of dried specimens of plants sent to the Hor-
ticultural Society from China, by Mr. Reeves, are a few
branches, with flowers, of a remarkable genus which is at pre-
sent undescribed, but which is of so curious a nature, and of
such importance with reference to the determination of some
natural affinities, that I have thought it deserving immediate
record ; especially as drawings of the fruit, which have been
subsequently obtained from the same indefatigable correspon-
dent of the Society, render its history tolerably complete.

The branches appear to be fragments of an evergreen tree ;
they are slender, rounded, and smooth. The nascent gemmce
are covered with a dense rufous pubescence. The leaves are
alternate, becoming, towards the extremities of the branches,
opposite by approximation ; their form is ovate-lanceolate
acuminate, and in size they vary from three inches to nearly six
in length ; the surface, even of the youngest, is perfectly smooth
on each side ; their veins are inconspicuous, the lowest pair of
vena primarise being divergent at an angle of about 40'', while
the others spread outwards at an angle of 55° or 60° ; the venae
arcuatae and externse are obscurely seen, but form together a
number of rhomboidal spaces, equal in diameter to nearly one
third of each side of the leaf; the proportion borne by the pe-
tiole to the lamina is variable, sometimes equalling one-fourth
of the length of the latter, and not un frequently being less than
one-sixth of its lengtli : this proportion not depending upon the
station of the leaves ; the petiole is smooth, half-round, and
thickened at the extremity, where it unites with the lamina.
StipulcB are none. The flowers are greenish-white, in terminal
thyrsoid compound racemes ; the upper part of the rachisy and
of its branches, is slightly protected by stellate pubescence ;
the pedicles are closely covered with pubescence of the same
nature, and have one subulate downy deciduous bracteola at the
base, and another towards the apex. The calyx is inferior,
campanulate, tapering a little towards the base, densely clothed
with stellate pubescence, bursting irregularly at the apex into

Il# Mr. Lindley on a New Genus of Plants,

four or five ovate teeth, which are somewhat imbricated during
aestivation, but which are separated by the growth of the petals
long before the expansion of the flower ; the veii|s of the calyx
are remarkably reticulated, and when cut, a considerable quan-
tity of mucilaginous viscid fluid is exuded. The petals are
whitish-green, hypogynous, with a convolute aestivation ; their
ungues are spatulate, and as long as the calyx ; their lamims
oblong, spreading flat, and then overlapping each other at the
base ; at the point of separation of the unguis and lamina is a
small callus, and on each side a notch upon the margin. The
stamens are seated upon a long, filiform, subclavate, smooth
torus } the filaments are consolidated into a capitate five-toothed
cup, nearly closed at the orifice, and on the outside of this cup
are placed the antherce, three to each tooth ; the latter are two-
celled, wath divaricating cells, which open longitudinally, and
are so entangled with each other that the whole surface of the
cup appears, when the antherse have burst, to consist of a single
many-celled anthera. The pollen is spherical and smooth. he
ovarium is seated within the cup of stamens, and is so entirely
concealed that it cannot be discovered till some part of the cup
is removed by violence ; it is ovate, smooth, and formed of five
inseparable cells, each of which has two ovula placed one above
the other, and attached to their placenta by their inner margin ;
the stigma is sessile, with five radiating lobes. From the
Chinese drawing, the half-ripe fruit appears to be fleshy, with
five deep angles, and five cells, without any remains of calyx,
and with a slight appearance of separation between the lobes.
The ripe fruit is an obovate, five-angled, five-celled, five-
valved, retuse, woody capsule, with a loculicidal dehiscence,
and no separable axis. The seeds are attached one to each
side of the valves, and are expanded at their lower end into a
wing.

From this description it is obvious that, with the single ex^
ception of the contents of the seed, we are in possession of all
that it is essential to know of the structure of this plant. The
next subject of consideration is its affinity.

The stellate pubescence, the thickening of the petiole at the
point where it expands into the lamina, the station of the sta-
mens -upon a long, filiform torus, the external position of th«

•Mr, Lindley on a New Genus of PlantSw ill

iantherfp, and the union of the filaments by threes into a cup
surrounding the ovarium, are all characters that forcibly call to
recollection the genus Sterculia. The calyx, indeed, in that
genus is generally divided much more deeply than in the plant
now under consideration, and the antherae are usually seated at
the base of the ovarium; but, on the other hand, in Sterculia
colorata of Roxburgh, which, if a distinct genus, (Erythropsis)
as I am inclined to believe, is nevertheless next of kin to Ster-
culia, the calyx is of the same figure and divided in the same
degree, and the antherse are also combined in a capitate cup
inclosing the ovarium. If, however, we pursue this compa-
rison further we find that, with the characters now adverted to,
the similarity ceases ; in Sterculia there are no petals, the
calyx has a valvular not imbricate aestivation, the cells of the
fruit separate into distinct folliculi, and do not combine into a
solid woody capsule, and the seeds are destitute of wings.

The fruit suggests so obviously some affinity with Ptero-
spermum, that it is next necessary to institute a comparison
with that genus. Stellate pubescence, a calyx divided into five
portions, five hypogynous unguiculate petals, and fifteen fertile
stamens united into a cup, seated on a stipitiform torus, and
surrounding the ovarium, a five-celled ovarium, a woody five-
celled capsule, with a loculicidal dehiscence, no axis, and
winged seeds ; all these characters are common to Pterosper-
mum and our plant; but on the other hand the points in which
they differ are of much importance. The aestivation of Pterosper-
tnum is valvate recurved not imbricate ; its calyx is five-parted,
not four — five-toothed ; its anthers have parallel not divaricating
cells, and are seated upon long distinct filaments, not sessile,
Hpon the outside of a capituliform cup ; and finally the petioles
of the leaves are not connected with the lamina by a thickened
space. The seeds are also winged at the apex, not at the
base, but upon this point it is not my wish to insist.

If the comparison thus instituted with Pterospermum and
Sterculia be attentively considered, we cannot fail to remark
that the subject of these observations is nearly equally related
to both ; to Pterospermum in its petals and fruit, to Sterculia
in its calyx and stamens. It must, therefore, be stationed be-
tween those two genera, thus confirming the propriety of M.

112 Mr. Lindley on a New Genus of Plants^

Kunth's combination of the Sterculiacese of Ventenat with the
Byttneriaceae of Mr. Brown ; and, in fact, breaking down every
barrier between them. )/,^Ujilci,

There are many other points that will suggest themselves to
the Botanist, in which this plant is highly worthy of considera-
tion, but for the present it wall be enough to give the botanical
characters with which it may stand recorded. It is named in
honour of John Reeves, Esq., now resident at Canton, to whom
we are indebted for our knowledge of it, from whose unwearied
exertions in the cause of science the botany of China has re*
ceived material assistance, and to whom our gardens are in-
debted for many of the fairest ornaments they contain.

REEVESIA.

Ord. Nat. Byttneriaceje ; Sterculiam {Erythr opsin) inter et
Pterospermum.

Calyx campanulatus, 5-dentatus, sestivatione imbricata, pube stellatii
tomentosus, bracteolatus. Petala 5, hypogyna, unguiculata, aestivatione
convoliita, callo inter unguem et laminam. Stamina in toro longo fili-
formi insidentia. Antherse 15, sessiles, in cyatho capituliformi, apice
tantum pervio, obsolete 5-dentato connatae, extrorsae, bilociilares, loculis
divaricatis intricatis, longitudinaliter dehiscentibus. Pollen sphsericiim
glabrum. Ovarium sessile, intra cyathum antheriferum, ovatum,
glabrura, 5-angulare, 5 -locnlare, loculis dispermis. Ovula margini locu-
lorum unum super alterum affixa, superiore basi concavo in inferiorem
incumbente. Stigma 5-lobum, simplicissimum, sessile. Capsula stipi-
tata, lignosa, obovata, 5-angularis, 5-loGularis, loculicido 5-valvis, axi

nullo. Semina cuique loculo duo basi alata. Arbor (Chinse) folii?

alternis exstipulatis, racemis terminalibus compositis, floribus albis.

1 . Reevesia thyrsoidea.

Habitat in China (v. s. sp. in Herb, et iconera in Biblidtheca Soc.
Hort.)

i i)ift lo

113

ASTRONOMICAL AND NAUTICAL
COLLECTIONS.

i. Elementary View of the Undulatory Theory 0/ Light.
By Mr. Fresnel.

[Continued jfrom the last Number.]

I SHALL not undertake to explain here in detail the reasons
and the calculations which lead to the general formulas that
I have employed to determine the position of the fringes and
the intensity of the inflected rays : but I think it right to
give at least a distinct idea of the principles on which this
theory rests, and particularly of the principle of interference^
which explains the mutual action of the rays of light on each
other. The name of interference was given by Dr. Young
to the law which he discovered, and of which he has made so
many ingenious applications.

This singular phenomenon, so difficult to be satisfactorily
explained in the system of emanation, is on the contrary so
natural a consequence of the theory of undulation, that it
might have been predicted from a general consideration of
the principles of that theory. Every body must have ob-
served, in throwing stones into a pond, that, when two groups
of waves cross each other on its surface, there are points at
which the water remains immoveable, when the two systems
are nearly of the same magnitude, while there are other places
in which the force of the waves is augmented by their con-
currence. The reason of this is easily understood. The
undulatory motion of the surface of the water consists of ver-
tical motions, which alternately raise and depress the particles
of the fluid. Now, in consequence of the intersection of the
waves, it happens, that at certain points of their meeting,
one of the two waves has an ascending motion belonging to
it, while the other tends at the same instant to depress the
surface of the liquid : consequently, when the two opposite
impulses are equal, it can neither be actuated by one nor the
other, but must remain at rest. On the contrary, at the
points in which the motions agree in their direction, and con-
spire with each other, the liquid, urged in the same direction

JULY—OCT. 1827. I

114 Astronomical and Nautical Collections,

by each of the forces, is raised or depressed with a velocity
equal to the sum of the effects of the two separate impulses,
or to the double of either of them taken singly, since they
are now supposed to be equal. Between these points of per-
fect agreement and complete opposition, which exhibit, one
the total absence of motion, the other the maximum of oscil-
lation, there are an infinity of intermediate points, at which
the alternate motion takes place with more or less of energy,
accordingly as they approach more or less to the places of
perfect agreement, or of complete opposition of the two
systems of motion which are thus combined, or superinduced
on each other.

The waves which are propagated in the interior of an
elastic fluid, though very different in their nature from those
of a liquid like water, produce mechanical effects by their
interference, which are exactly of the same kind, since they
consist in alternate oscillatory motions of the particles of the
fluid. In ^fact,.it is sufficient that these motions should be
oscillatoiy, that is, that the particles should be carried
by them alternately in opposite directions, in order that
the effects of one series of waves may be destroyed by those
of another series of equal intensity ; for, provided that the
difference of the route of the two groups of waves [derived
from the same origin] be such, that for each point of the
fluid the motions in one direction, belonging to the first series,
correspond to the motions, belonging to the second, in the
opposite direction, they must perfectly neutralise each other,
if their intensity is equal : and the particles of the fluid must
remain in repose. This result will always hold good, what-
ever may happen to be the direction of the oscillatory mo-
tion, with regard to that in which the undulations are propa-
gated ; provided that the direction of the oscillatory motion
be the same in the two series to be combined. In the waves
which are formed on the surface of a liquid, for example, the
direction of the oscillation is [principally] vertical, while the
waves are propagated horizontally, and consequently in a di-
rection perpendicular to the former ; in the undulations of
sound, on the contrary, the oscillatory motion is parallel to
the direction of the propagation of the sound, [or rather is

Astronomical and Nautical Collections, 115

identical with it] ; and these undulations, as well as the waves
of water, are subject to the laws of interference.

The undulations formed in the interior of a fluid have here
been mentioned in a general manner : in order to form a dis-
tinct idea of this mode of propagation, it must be remarked,
that when the fluid has the same density and the same elas-
ticity in every direction, the agitation produced in any point
must be propagated on all sides with the same velocity : for
this velocity of propagation, which must not be confounded
with the absolute velocity of the particles, depends only on
the density and elasticity of the fluid. It follows thence that
all the points, agitated at the same instant in a similar man-
ner, must be found in a spherical surface, having for its centre
the point which is the origin of the agitation : so that these
undulations are spherical, while the waves, which are seen on
the surface of a liquid, are simply circular.

We give the name oirays to the right lines drawn from the
centre of agitation to the different points of this spherical
surface ; and these rays are the directions in which the motion
is propagated. This is the meaning of the term sonorous
rays in acustics, and oiluminous rays or rays of light in the
system which attributes the phenomena of light to the vibra-
tions of a universal fluid, to which the name of ether has been
given.

The nature of the different elementary motions, of which
each wave is composed, depends on the nature of the different
motions which constitute the primitive agitation. The sim-
plest hypothesis that can be entertained concerning the form-
ation of the luminous undulations, is, that the small oscilla-
tions of the particles of the bodies, which produce them, are
analogous to those of a pendulum removed but little from its
point of rest ; for we must conceive the particles of bodies,
not as immoveably fixed in the positions which they occupy,
but as suspended by forces which form an equilibrium in all
directions. Now, whatever the nature of such forces may be,
as long as the displacement of the particles is but small in
proportion to the extent of their sphere of action, the accele-
rating force which tends to restore them to their natural po-
sition, and which thus causes them to oscillate on each side of it,
may always, without eensible error, be considered as propor-

12

116 Astronomical and Nautical Collections.

tional to the magnitude of that displacement : so that the law
of their motion must be the same as that of the motion of the
pendulum, and of all small oscillations in general. This
hypothesis, which is suggested by the analogy with other
natural phenomena, and which is the simplest that can be
formed respecting the vibrations of the luminous particles,
may be considered as experimentally confirmed by the obser-
vation, that the optical properties of light are all indepen-
dent of any circumstances which cause the greatest difference
in the intensity of the vibrations : so that the law of their
motion must be presumed to be the same for the greatest as
for the smallest.

It follows from this hypothesis respecting the small oscil-
lations, that the velocity of the vibrating particle at each
instant is proportional to the sine of an arc, represent-
ing the time elapsed from the beginning of the motion,
taking the circumference for the whole time required for
the return of the particle to the same point, that is,
the time occupied by two oscillations, the one forwards
and the other backwards. Such is the law according to
which I have calculated the formulas which serve to deter-
mine the effect of any number of systems of waves of which
the intensities and the relative positions are given. These
formulas will be found in the Annals of Chemistry, vol. xi.,
page 254 : [they may be applied with security to the pheno-
mena there considered, though the perfect accuracy of the
hypothesis in all possible cases may be questioned, upon the
grounds of the microscopical observations on the motions of
vibrating chords, published by Dr. Young in the Philosophi-
cal Transactions for 1800. Tr.] Without entering into the
details of the calculations, I think it necessary to show in what
manner the nature of the undulation depends on the kind of
motion of the vibrating particles.

^Let us suppose, in the fluid, a little solid plane which is
removed from its primitive position, towards which it is urged
by a force proportional to the distance. At the beginning of
its motion, the accelerative force produces in it an infinitely-
small velocity only ; but its action continuing, the effects
become accumulated, and the velocity of the solid plane goes
on continually to increase, until the moment of its arrival at

Astronomical and Nautical Collections, 117

the position of equilibrium, in which it would remain, but
for the velocity which it has acquired ; and it is by this velo-
city only, that it is carried beyond the point of equilibrium.
The same force which tends towards this point, and which
now begins to act in a contrary direction, continually di-
minishes the velocity, until it is completely annihilated ; and
then the force continuing its action produces a velocity in the
contrary direction, which brings the plane back to its place
of equilibrium. This velocity again is very small at the com-
mencement of the return of the particle, or plane, and in-
creases by the same degrees as it had before diminished, until
the instant of the arrival of the particle at the neutral point,
which . it passes with the velocity previously acquired : but
when it has passed this point, the motion is diminished more
and more by the effect of the force tending towards it, and
its velocity is reduced to nothing when it arrives at the place
of the commencement of the motion. It then recommences,
at similar periods, the series of motions which have been de-
scribed, and Avould continue to oscillate for ever, but for the
effect of the resistance of the surrounding fluid, the inertia
of which continually diminishes the amplitude of its oscilla-
tions, and finally extinguishes them at the end of a longer or
shorter time, according to circumstances. [It must not be
inferred from this explanation, that the particles of a fluid
transmitting an undulation have any tendency to vibrate for
ever : on the contrary it has been admitted by the best writers
on the theory of sound, that all the motions which constitute
it, as considered in a fluid, are completely transitory in their
nature, and have no disposition to be repeated after having
been once transmitted to a remoter part of the fluid. Tr.]

Let us now consider in what manner the fluid is agitated
by these oscillations of the solid plane. The stratum imme-
diately in contact with it, being urged by the plane, receives
from it at each instant the velocity of its motion, and com-
municates it to the neighbouring stratum, which it forces
forwards in its turn, and from which the motion is com-
municated successively to the other strata of the fluid ; but
this transmission of the motion is not instantaneous, and it is
only at the end of a certain time that it arrives at a deter*

118 Astronomical and Nautical Collections.

minate distance from the centre of agitation. This time is the
shorter, as the fluid is less dense, and more elastic ; that is,
composed of particles which possess a greater repulsive force.
This being granted, let us assume, in order to facilitate the
explanation, the moment when the moveable plane is returned
to the initial situation, after having performed two complete
oscillations in opposite directions : at this moment, the nascent
velocity, which it had at first, is transmitted to a stratum of
the fluid removed from the centre of agitation by a distance
which we may represent by d. Immediately afterwards, the
velocity of the moveable plane, which has a little augmented,
has been communicated to the stratum in contact with it :
** hence it has passed successively through all the following
strata ;" and at the moment when the first agitation arrives
at the stratum of which the distance is d, the second has
arrived at the stratum immediately before it. Continuing
thus to divide, in our imagination, the duration of the two
oscillations of the moveable plane into an infinity of small
intervals of time, and the fluid comprehended in the length d,
into an equal number of infinitely thin strata, it is easy to
perceive, by the same reasoning, that the different velocities
of the moveable plane, at each of these instants, are now dis-
tributed among the corresponding strata ; and that thus, for
example, the velocity which the plane possessed at the middle
of the first oscillations in the direction of the motion, must
have arrived, at the instant in question, at the distance | d :
so that it is the stratum at this distance which possesses at
the moment the greatest direct velocity ; and in the same
manner when the plane arrived at the limit of its first direct
oscillation, its velocity was extinguished, and the same absence
of motion will be found at the distance J d.

It is always supposed, that the oscillations of the plane are
so minute in comparison with the length d, that their extent
may be neglected in this calculation : and this hypothesis is
actually consistent with the fact, since there is every reason
to suppose that the excursions of the incandescent particles
are very small in comparison with the extent of an undula-
tion, which, though an extremely minute space, is still an ap-
preciable quantity, and may be actually measured. Besides,

Astronomical and Nautical Collections. 119

even if the amplitude of these oscillations were not in the first
instance so wholly inconsiderable, it would be sufficient to
consider an undulation at a greater distance from the centre
of agitation, in order that their extent might be diminished in
any required proportion.

In the second, or retrograde oscillation, the plane, return-
ing through the same space, must communicate to the stratum
of fluid in contact with it, and to the rest in succession, a mo-
tion in a direction contrary to that of the first oscillation ;
for when the plane recedes, the stratum in contact with it,
urged against the plane by the elasticity or the expansive
force of the fluid, necessarily follows it, and fills up the vacuum
which its retrograde motion tends to produce. For the same
reason, the second stratum is urged against the first, the third
against the second, and so forth. It is thus that the retro-
grade motion is communicated, step by step, to the most dis-
tant strata : its propagation is efiected according to the same
law that governs the direct motion ; the only diff*erence is in
the direction of the motions, or, in the language of mathe-
matics, in the sign of the velocities which are imparted to the
molecules of the fluid. We see then that the different velo-
cities which have existed in the solid plane, during its second
oscillation, must exist at the moment which we are considering,
in the different strata comprehended in the other half of o?, but
with contrary signs. Thus the velocity, for example, which
the plane had in the middle of the second oscillation, which
is its maximum of retrograde velocity, must now be found in
the fluid stratum situated at the distance | d from the centre
of agitation, while the maximum of direct velocity is found,
at the same instant, in the stratum which is at the distance | d
from the centre of agitation.

The extent of the fluid, agitated by the two opposite oscil-
lations of the solid plane, is what we call the breadth of
an entire undulation, and we may consequently give the
name of semiundulation to each of the parts actuated by the
opposite undulations ; the whole constituting a complete oscil-
lation, since it comprehends the return of the vibrating plane
to the initial situation. It is obvious, that the two semiundu-
lations, which compose the complete undulation, exhibit, in

120 Astronomical and Nautical Collections,

the fluid strata which they contain^ velocities absolutely equal
in magnitude, but with contrary signs, that is to say, carry-
ing the particles of the fluid in opposite directions. These
velocities are the greatest in the middle of each of the
semiundulations, and decrease gradually towards their extre-
mities, where they entirely vanish : so that the points of rest,
and of the greatest velocities positive and negative, are sepa-
rated from each other by intervals of one fourth of an undu-
lation. .' Olio z>iiS .aoiii!

The length of an undulation, d, depends o» two things :
first, on the promptitude with which the motion is propa-
gated in the fluid ; and secondly, the duration of the complete
oscillation of the vibrating plane ; for the longer this dura-
tion, and the more rapid the propagation of the motion, the
greater will be the distance to which the first agitation has
been extended at the instant of the return of the solid plane
to its initial situation. If the oscillations are all performed
in the same medium, the velocity of propagation remaining
the same, the length of the undulations will be simply pro-
portional to the duration of the oscillations of the vibrating
particles from which they originate. As long as the vibrating
particles continue to be subjected to the same forces, it
follows from the principles of mechanics that each of their
minute oscillations will occupy the same time, whatever their
extent may be ; so that the corresponding undulations of the
fluid will continue to be of the same length ; they will only
difi'er from each other in the greater or less extent of the ele-
mentary vibrations of the particles, which will be propor-
tional to the extent of the luminous particles ; for it appears
from what has already been stated, that each stratum of the
fluid repeats exactly all the motions of the vibrating particle.
The greater or less amplitude of the oscillations of the strata
of the fluid determines the degree of absolute velocity with
which they move, and consequently the energy, but not the
nature of the sensation which they excite, which must depend,
according to every analogy, upon the duration of the oscilla-
tions. It is thus that the nature of the sounds, transmitted by
the air to our ears, depends entirely on the duration of each
of the oscillations executed by the air, or by the sonorous

Astronomical and Nautical Collections, 121

body which puts it in motion ; and tliat the greater or less
amplitude or energy of the oscillations only augments or di-
minishes the intensity of the sound, without changing its
nature, that is, its tone, or pitch.

The intensity of the light must depend then on the inten-
sity of the vibrations of the ether ; and its nature, that is to
say, the sensation of colour that it produces, will depend on
the duration of each oscillation, or on the length of the un-
dulation, the one of these being proportional to the other.
[We find, however, nothing in light of the same colour that
is at all analogous to the different register, quality, or timbre
of a sound, by which, for instance, the sound of a violin differs
from that of a flute in unison with it : the subordinate, or
harmonic tones of the sound having nothing in light to cor-
respond with them. Tr.]

The duration of the elementary oscillation remaining the
same, the absolute velocity of the ethereal particles, at the
corresponding periods of the oscillatory motions, is, as we have
seen, proportional to its extent. It is the square of this velo-
city, multiplied by the density of the fluid, that represents
what is called the living force in mechanics, or otherwise the
energy or impetus of the particles, which is to be taken as
the measure of the sensation produced, or of the intensity of
the light : thus, for example, if in the same medium, the
amplitude of the oscillation is doubled, the absolute velo-
cities will also be doubled, and the living force, or the inten-
sity of the light, will be quadrupled.

We must, however, take care not to confound this abso-
lute velocity of the particles of the fluid with the velocity of
the propagation of the agitation. The first varies according to
the amplitude of the oscillations ; the second, which is nothing
but the promptitude with which the motion is communicated
from one stratum to the other, is independent of the inten-
sity of the vibrations. It is for this reason, that a weak sound
is transmitted by the air with the same velocity as a stronger
one ; and that the least intense light is propagated with the
same rapidity as the brightest. When we speak of the velo-
city of light, we always speak of the velocity of its propaga-
tion. Thus, when we say that light passes through 200 thou*

122 Astronomical and Nautical Collections.

sand miles in a second, we do not mean, according to the
undulatory system, that such is the absolute velocity of the
ethereal particles ; but that the motion communicated to
the ether employs only a second to pass to a stratum at the
distance of 200 thousand miles from its origin.

In proportion as the undulation becomes more distant from
the centre of agitation, the motion, spreading over a greater
distance, must be weakened in every part of the wave. It
is shown by calculation, that the amplitude of the oscillatory
motion, or the absolute velocity of the particles concerned in
it, is inversely proportional to the distance from the centre
of agitation. Consequently, the square of this velocity is
inversely proportional to the square of the distance, and the
intensity of the light must be inversely as the square of the
distance from the luminous point. It must be remarked, that,
for the same reasons, the sum of the living forces of the whole
undulation remains unaltered ; for, on one side the length of
the undulation d, which may also be called its thickness, is
invariable, and its extent of surface augmenting in propor-
tion to the square of the distance from the centre, the quan-
tity, or mass of the fluid agitated, is proportional to the same
square : and since the squares of the absolute velocities are
diminished in the same proportion as the masses have aug-
mented, it follows that the sum of the products of the masses
by the squares of the velocities, that is to say, the sum of the
living forces, remains unaltered. It is a general principle of
the motion of elastic fluids, that however the motion may be
extended or subdivided, the total sum of the living forces re-
mains constant ; and this is the principal reason why the living
force must be considered as the measure of light, of which the
total quantity always remains very nearly the same, at least
as long as it continues to pass through perfectly transparent
mediums.

It may be remarked, that black substances, and even the
most brilliant metallic surfaces, by no means reflect the whole
of the light which falls on them ; bodies which are imper-
fectly transparent, and even the most transparent, when of
great thickness, absorb also, to use a common expression, a
considerable portion of the light that is passing through

Astronomical and Nautical Collections, 123

them : but it must not be inferred that the principle of living
forces is inapplicable to these phenomena ; it follows, on the
contrary, from the most probable idea that can be formed of
the mechanical constitution of bodies, that the sum of the
living force must remain always the same, as long as the
accelerating forces tending to bring the particles to their na-
tural positions, remain unchanged, and that the quantity of
jiving force which disappears in the state of light, instead of
being annihilated, is reproduced in the form of heat.

In order to obtain a correct idea of the manner in which
the oscillation of a small solid body occasions undulations in
an elastic fluid, it has been only necessary to consider a
complete oscillation of the solid plane, which produces an
entire undulation. If we suppose the oscillations of the plane
to be continually repeated, we shall have a series of undula-
tions instead of a single one : and they will follow each other
without intermission, provided that the vibrations of the par-
ticle first agitated have been regular. Such a series of re-
gular and uninterrupted luminous motions I call a system of
undulations.

It is natural to suppose, on account of the prodigious ra-
pidity of the vibrations of light, that the luminous particles
may perform a great number of regular oscillations in each
of the different mechanical situations in which they are placed
during the combustion or the incandescence of the luminous
body, although these circumstances may still succeed each
other in extremely short periods ; for the millionth part of a
second is sufficient to exhibit, for example, 545 millions of
undulations of yellow light ; so that the mechanical distur-
bances, which derange the regular succession of the vibra-
tions of the luminous particles, or which even change their
nature, might be repeated a million times in a second without
preventing the regular succession of more than 500 millions
of consecutive undulations in each state of the particle. We
shall soon have occasion to apply this observation to the de-»
termination of the circumstances in which the interference
of luminous waves is capable of producing sensible effects.

We have seen that each undulation produced by an oscil-
latory motion was composed of two semiundulations, which

124^. Astronomical and Nautical Collections,

occasioned in the particles of the fluids velocities exactly equal
in their intensity, though opposite in the direction of the
motions. Let us at first suppose that two whole undula-
tions, moving in the some line and in the same direction,
differ half an undulation in their progress : they will then be
superinduced on each other through one half of their length,
or of their breadth, as we should say in speaking of the waves
of a liquid : but I here use in preference the term length as
applied ta; the interval between the two points which are
similarly affected by the motions of two consecutive undula-
tions. In the supposed case of the coincidence of one half of
each of the undulations, the interference will only take place
with respect to the parts so coinciding : that is, to the latter
half of the first undulation, and the preceding half of the
second : and if these two semiunJulations are of equal inten-
sity, since they tend to give, to the same points of the ether,
impulses directly opposite, they will wholly neutralise each
other, and the motion will be destroyed in this part of the
fluid, while it will subsist without alteration in the two other
halves of the undulations. In such a case, therefore, half of
the motion only would be destroyed.

If now we suppose that each of these undulations, differ-
ing in their progress by half the whole length of each, is
preceded and followed by a great number of other similar un-
dulations; then, instead of the interference of two detached
undulations, we must consider the . interference of two sys-
tems of waves, which may be supposed equal in their number
and their intensity. Since, by the hypothesis, they differ
half an undulation in their progress, the semiundulations of
the one, which tend to cause in the particles of ether a mo-
tion in one direction, coincide with the semiundulations of
the other, which urge them in the opposite direction, and
these two forces hold each other in equilibrium, so that the
motion is wholly destroyed in the whole extent of these two
systems of waves, except the two extreme semiundulations,
which escape from the interference. But these semiundu-
lations will always constitute a very small part of tbe whole
series to be considered. •>«(; ^< '^^

This reasoning is obviously applicable to such systems only

Astronomical and Nautical Collections, 125

as are composed of undulations of the same length; for if
the waves were longer one than the other, however small
their difference might be, it would happen at last that their
relative position would not be the same throughout the ex-
tent of the groups ; and while the first destroyed each other
almost completely, the following ones would be less in oppo-
sition, and would ultimately agree completely with each
other: hence there would arise a succession of weak and
strong vibrations analogous to the beatings which are pro-
duced by the coincidence of two sounds differing but little from
each other in their tone ; but these alternations of weaker and
stronger light, succeeding each other with prodigious rapi-
dity, would produce in the eye a continuous sensation only.
-»iflt is very probable that the impulse of a single luminous
semiundulation, or even of an entire undulation, would be
too weak to agitate the particles of the optic nerve, as we
find that a single undulation of sound is incapable of causing
motion in a body susceptible of a sympathetic vibration.
It is the succession of the impulse, which, by the accumu-
lation of the single effects, at last causes the sonorous body
to oscillate in a sensible manner ; in the same manner as the
regular succession of the single efforts of a ringer is at last
capable of raising the heaviest church bell into full swings.
Applying this mechanical idea to vision, supported as it is
by so many analogies, we may easily conceive that it is
impossible for the two remaining semiundulations, which
have been mentioned, to produce any sensible effect on the
retina ; and that the result of such a combination of the
two systems must be the production of total darkness.

If again we suppose the second system of undulations to
be again retarded half an undulation more, so as to make
the difference of the progress an entire undulation,, the coin-
cidence in the motions of the two groups will be again
restored, and the velocities of oscillation will conspire and
be augmented in the points of superposition; the intensity
of the light being then at its maximum. ; , ;->

Adding another semiundulation to the difference in the
progress of the two systems, so as to make it an interval and

126 Astronomical and Nautical Collections,

a half, it is obvious that the semiundulations, superinduced
on each other, will now possess opposite qualities, as in the
case of the half interval first supposed : and that all the
undulations must in this manner be neutralised, except
the extreme three semiundulations on each side, which will
be free from interference. Thus almost the whole of the
motion will again be destroyed, and the combination of the
two pencils of light must produce darkness, as in the case first
considered.

Continuing to increase the supposed difference by the
length of a semiundulation at each step, we shall have alter-
nately complete darkness and a maximum of light, accord-
ingly as the difference amounts to an odd or an even number
of semiundulations : that is, supposing always that the sys-
tems of undulations are of equal intensity : for if the on6
series were less vivid than the other, they would be inca-
pable of destroying them altogether : the velocities of the
one series would be subtracted from those of the other, since
they would tend to move the particles of the ether in con-
trary directions, but the remainders would still constitute
light, though feebler than that of the strongest single pencil.
Thus the second pencil would still occasion a diminution of
the light : but the diminution would be the less sensible as
the pencil is supposed to be weaker.

Such are the consequences of the principle of the inter-
ference of undulations, which agree perfectly, as we have
seen, with the law of the mutual influence of the luminous
rays which is deduced from experiment : for the results are
expressed precisely in the same words, if we give the name
of length of undulation to the difference of routes which had
been represented by the symbol d. Admitting, therefore,
as there is every reason to believe, that light consists in the
undulations of a subtile fluid, the period d, after which the
same effects of interference are repeated, must be the length
of an undulation.

It appears from the table already given for the seven
principal kinds of coloured rays, that this period d, or the
length of the undulation, varies greatly, according to the

Astronomical and Nautical Collections. 127

colour of the light, and that for the extreme red rays, for
example, it is [more than] half as great again as for the violet
rays situated at the other extremity of the spectrum.

It may easily be imagined that the number of different
undulations is not limited to the seven principal ones which
are indicated in the table, and that there must be a multi*
tude of intermediate magnitudes, and others beyond the red
and the violet rays : for the ponderable particles, of which the
oscillations give rise to them, must be subjected to forces that
are infinitely varied, in the combustion or the incandescence
of the bodies which excite the motions of the ether: and it is
on the energy of these forces that the duration of each oscilla-
tion depends, and consequently the length of the undulation
produced by it. It is found that all the undulations com-
prehended [in the air] between the lengths .0000167 E. L
and .0000244, are visible ; that is, are capable of exciting
vibrations in the optic nerve : the rest are only sensible by
their heat, or by the chemical effects which they produce.

It has been remarked, that when two systems of waves
differ half an undulation in their progress, two of the semi*
undulations must escape from interference ; that six must be
exempt when the difference amounts to three semiundula-
tions; and that, in general, the number of undulations exempt
from interference is equal to the number of lengths of a semi^
undulation separating the corresponding points of the two
systems. While this number is very small in proportion to
that of the waves contained in each system, the motion must
be nearly destroyed, as in the case of the exemption of a
single undulation. But it may be imagined that, as we in-
crease the difference of the progress of the two pencils, the
undulations exempted from interference may become a mate-
rial portion of each group, and that it may finally become so
great as to separate the groups entirely from each other ;
and in this case the phenomena of interference would no
longer be observable. If, for example, the groups of undu-
lations consisted but of a thousand each, a difference of one-
twentieth of an inch in their routes would be much more
than sufficient to prevent the interference of the rays of all
kinds.

128 Astronomical and Nautical Collections.

But there is another much more powerful reason which
prevents our perceiving the effects of the mutual influence of
the systems of waves when the difference of their routes is
considerable; which is the impossibility of rendering the
light sufficiently homogeneous : for the most simple light
that we can obtain consists still of an mfinity of heteroge-
neous rays, which have not exactly the same length of undu-
lation ; and however slight the difference may be, when it is
repeated a great number of times, it produces of necessity,
as we have already seen, an opposition between the modes of
interference of the various rays, which then compensates for
the weakening of some by the strengthening of others ;
[while the shades of colour are not sufficiently distinct to
allow the eye to remark the difference.] This is without
doubt the principal reason why the effects of the mutual
interference of the rays of light become insensible when the
difference of the routes is very considerable, so as to amount
to 50 or 60 times the length of an undulation.

It has already been laid down as one of the conditions
necessary for the appearance of the phenomena of interfer-
ence, that the rays which are combined should have issued
at first from a common source : and it is easy to account for
the necessity of this condition by the theory which has now
been explained.

Every system of waves, whicli meets another, always exer-
cises on it the same influence when their relative positions
are the same, whether it originates from the same source or
from different sources ; for it is clear that the reasons, by
which their mutual influence has been explained, would be
equally applicable to either case. But it is not sufficient
that this influence should exist, in order that it may become
sensible to our eyes : and for this purpose the effect must
have a certain degree of permanence. Now this cannot
happen when the two systems of waves which interfere are
derived from separate sources. For it is obvious that the
particles of luminous bodies, of which the vibrations agitate
the ether, and produce light, must be liable to very frequent
disturbances in their oscillations, in consequence of the rapid
changes which are taking place around them, which may

Astronomical and Nautical Collections, 129

nevertheless be perfectly reconciled, as we have seen, with
the regular continuance of a great number of oscillations in
each of the series separated by these perturbations. This
being admitted, it is impossible to suppose that these per-
turbations should take place simultaneously and in the same
manner in the vibrations of separate and independent par-
ticles ; so that it will happen, for example, that the motions
of the, one will be retarded by an entire semioscillation, while
those of the other will be continued without interruption,
or will be retarded by a complete oscillation, a change
which will completely invert the whole effects of the inter-*
ference of the two systems of undulations Avhich originate
from them; since ifthey had agreed on the first supposition,
they would totally disagree on the second. Now these oppo-
site effects, succeeding each other with extreme rapidity, will
produce in the eye a continuous sensation only, which will
be a mean between the more or less lively sensations that
they excite, and will remain constant, whatever may be the
difference of the routes described.

But the case is different when the two luminous pencils
originate from a common source : for then the two systems
of waves, having originated from the same centre of vibra-
tion, undergoing these perturbations in the same manner and
at the same instant, undergo no changes in their relative po-
sitions : so that if they disagreed in the first instance at any
given point, they would continue to disagree at all other
times ; and if their motions cooperated at first, they would
continue to agree as long as the centre of vibration continued
to be luminous : so that in this case, the effects must remain
constant, and must therefore be sensible to the eye. This
is therefore a general principle, applicable to all the effects
produced by luminous undulations ; that in order to become
sensible, they must be permanent.

We have hitherto supposed that the two systems of waves
were moving exactly in the same direction, and tliat conse-
quently their elementary motions, to be combined with
each other, were precisely limited to one single line : this is
the simplest case of interference, and the only one in whicH
the one motion can be completely destroyed by the other:

JULY— OCT. 1827. K

J.30 Astronomical and Nautical Collectidri»,

for in order that this effect may be produced, not only the-
two forces must be equal and in contrary directions, but they
must also act in the same right line, or be directly opposed,
to each other.

The phenomenon of coloured rings, and that of the colours
developed by polarised light in crystallised plates, present a
particular case of interference, in which the undulations are
exactly parallel. But in the phenomena of diffraction, or in
the experiment with the two mirrors, which has been already
described, the rays which interfere always form sensible
though very small angles with each other. In these cases
the impulses to be combined with each other at the same
points, as belonging to the two systems of undulations, will also
act in directions forming sensible angles with each other :
but on account of the smallness of these angles, the result of
the two impulses is almost exactly equal to their sum, when
the impulses act in the same direction, and to their differ-
ence, when they are in contrary directions. Thus, in the
points of agreement or disagreement, the intensity of the
light will be the same as if the directions agreed more per-
fectly ; at least the nicest eye will not be able to discover
any difference in them. But although, with respect to the
intensity of the light, this case of interference resembles that
which has already been considered, there are other differ-
ences which modify the phenomenon very greatly, both with
respect to its general form, and to the circumstances neces-
sary for producing it.

We may take, as a convenient example, the case of di^
verging rays originating from the same luminous point,
and reflected by two mirrors slightly inclined to each other,
so as to produce two pencils meeting each other in a sen-
sible angle : the two systems of waves will then meet each
other with a slight inclination ; and it follows from this
obliquity, that if a semiundulation of the first system coin-
Ciides perfectly in one point with, a semiundulation of the
second, urging the fluid in the same direction, it must sepa-
rate from it to the right and left of the point of intersection*
and must coincide, a little further off, on one side with the
preceding semiundulation which is in a contrary direction^

Asttonomkal and Nautical Collection^. 131

and on the other side with the following semiundulation,
and then be separated from this again, and at a distance
twice as great as the first, must coincide with the second
semiundulation before and behind it, of which the actions
will coincide with its own : whence there will arise, on
the surface of this undulation, a series of lines, at equal
distances from each other, in which the motion is destroyed
and doubled alternately by the action of the second series.
Thus if we receive this luminous undulation on a white card,
we shall observe on it a series of dark and bright stripes, if
the light employed is homogeneous ; or coloured fringes of
different tints, if we employ white light for the experiment. >'

R A C B _1SL.

INI JV r

\ \ //xx

• 'This will be more easily understood by the inspection of a
figure, which represents a section of the two mirrors and of
the reflected undulations, formed by a plane drawn from the'
luminous point perpendicularly to thfe mirrors represented
by DE and DF. The luminous point is supposed to be
S, and A and B are the geometrical positions of its two'
images, which are determined by the perpendiculars SA and
SB falling from Son the mirrors, taking in them PA = SP.

K 2

132 Astronomical and Nautical Collections,

and QB = SQ. The points A and B, thus found, are the
centres of divergence of the rays reflected from the respective
mirrors, according to the well known law of reflection.
Thus, in order to have the direction of the ray reflected at
any point G of the mirror DF, for example, it is sufficient
to draw a right line through B and G, which will be the
direction of the reflected ray. Now it must be remarked,
that, according to the construction by which the position of
B is found, the distances BG and SG will be equal, and
thus the whole route of the ray coming from S and arriving
at b, is the same as if it had come from B. This geometrical
truth being equally applicable to all the rays reflected by
the same mirror, it is obvious that they will arrive at the
same instant at all the points of the circumference n'bm, de-
scribed on the point B as a centre, with a radius equal to
Bb ; consequently this surface will represent the surface of
the reflected undulation when it arrives at b, or, more cor-
rectly speaking, its intersection with the plane of the figure :
the surface of the undulation being understood as relating to
the points which are similarly agitated at the same instant :
the points being all, at the commencement of the whole oscil-
lation, for example, or at the middle or the end, completely
at rest ; and in the middle of each .semioscillation, possessed
of the maximum of velocity.

In order to represent the two systems of reflected undu-
lations, there are drawn, with the points A and B for their
centres, two diff'erent series of equidistant arcs, separated from
each ether by an interval which is supposed equal to the length
of a semiundulation. In order to distinguish the motions in
opposite directions, the arcs on which the motions of the ethe-
real particles are supposed to be direct, are represented by full
lines, and the maximum of the retrograde motions are indi-
cated by dotted lines. It follows that the intersections of the
dotted lines with the full lines are points of complete dis-
cordance, and of course show the middle of the dark stripes ;
and, on the contrary, the intersections of similar arcs show the
points of perfect agreement, or the middle of the bright
stripes. The intersections of the arcs of the same kind are
joined by the dotted lines by, br, b'p, and those of arcs of

Astronomical and Nautical Collections, 133

different kinds by the full lines n'o\ no, no, no : these latter
representing the successive positions or the trajectories of
the middle points of the dark stripes^ an^^ \]xf ^i^vmer the
trajectories of the bright bands, , , ,{ • t .. ', ,,.

It has been necessary to magnify very greatly in this
figure the real length of the luminous undulations, and to
exaggerate the mutual inclination of the two mirrors, so that
we must not expect an exact representation of the pheno-
menon, but merely a mode of illustrating the distribution of
the interferences, in undulations which cross each other with
a slight inclination, h nto

It is easy to deduce from geometrical considerations, that
the length of these fringes is in the inverse ratio of the mag-
nitude of the angle made by the two pencils which interfere,
and that the interval, comprehended between the middle
points of two consecutive dark or bright bands, is as much
greater than the length of the undulation, as the radius is
greater than the sine of the angle of intersection.

In fact the triangle b7ii, formed by the right line bi, and
the two circular arcs ni and nb, may be considered as recti-
linear and isosceles, on account of the smallness of the arcs ;
and the sine of the angle b n i, considered as very small, may

lb
be called — : so that bn being the radius, ib will represent
bn

the sine of the angle b n i, which has its legs perpendicular

to those of the angle AbB: consequently, these angles being

equal, one of them may be substituted for the other ; and

representing by i the angle A ^ B, formed by the reflected

rays, we have bn == — — ; consequently nn, which is twice

bn^ wm be equal to -r— .. But nn is the distance between

the ihfddle points of two consecutive dark stripes, and is
the distance which has been called the breadth of a fringe ;
and i5 being the breadth of a semiundulation, according to
the construction of the figure, 2ib will be that of a whole
undulation ; consequently the breadth of a fringe may be
said to be equal to the length of an undulation divided by
the [numerical] sine of the angle made by the reflected rays

134 Astronomical and Nautical Collection^..

with each other, whicli is also the angle under which the
interval AB would appear to an eye placed at b. We find
another equivalent formula, by remarking that the two tri-
angles, b 711 and AbB, are similar, whence we have the pro-

portion ^w: ^2 = A^:AB, and bn = — ,or2bn =:

^ AB

: which implies that we may find the numerical

breadth of a fringe by multiplying the length of an undula-
tion by the distance of the images A and B from the plane
on which the fringes are measured, and dividing the product
by the distance of the two images.

It is sufficient to inspect the figure, in order to be con-
vinced of the necessity of having the two mirrors nearly in
the same plane, if we wish to obtain fringes of tolerably large
dimensions ; for in the little triangle b n z, the side b ^, which
represents the length of a semiundulation, being little more
than the hundred thousandth of an inch for the yellow rays,
for example, the side bn^ which measures the half breadth of
a fringe, can only become sensible when bn \% very little
inclined to 2 7i, so that their intersection may be remote from
ib ; and the inclination oi bn to in depends on the distance
AB, which is the measure of the inclination of the mirrors.

If A and B, instead of being the images of the luminous
point, were the projections of two very fine slits cut in a
screen RN, through which the rays of light were admitted
from a luminous point placed behind the screen in the conti^
nuation of the line ^DC, the two paths described between
the point and the slits A and B being equal, it would be suf-
ficient to compute the paths described by the rays, beginning
from A and B, in order to have the differences of their
lengths; and it is obvious in this case, that the calculation^
which we have been making of the breadth of the fringes,
produced by the two mirrors, would remain equally applir
cable, at least as long as each slit remained narrow enough
to be considered as a single centre of undulation, relatively
to the inflected rays which it transmits. It may therefore
be said that the breadth of the fringes, produced by two very
fine slits, is equal to the length of an undulatioij supposed

Astronomical and Nautical Collections^ I3i5

to be multiplied by the interval between the two slits, and
divided by the distance of the screen from the wires of the
micrometer employed for measuring the fringes.

This formula is also applicable to the dark and bright
stripes which are observed in the shadow of a narrow sub-
stance, substituting the breadth of this substance for the
interval which separates the two slits^ as long as the stripes
are far enough from the edges of the shadow : for when
they approach very near to the edges, it is shown, both by
theory and by experiment, that this calculation does not repre-
sent the facts with sufficient accuracy; and it is not perfectly
correct in all cases, either for the fringes within the shadow,
or. for those of the twjo slits, but only for the fringes pro-
duced by the mirrors, which exhibit the simplest case of the
interference of rays slightly inclined to each other. In order
to obtain from the theory a rigorous determination of the
situation of the dark and light stripes in the two former
cases, it is not sufficient to calculate the effect of two systems
of undulations, but those of an infinite number of similar
groups must be combined, according to a principle which
will shortly be explained, in treating of the general theory
of diffraction.

ii. Ride for the Correction of a Lunar Obseevation.
j?y Mr. William WisEMAti, of Hull,

Rule. >

Add together the reserved logarithm (found as directedi
page 111 and 1 12 of the Appendix to the third edition of the
Requisite Tables) the log. sines of half the sum, and half the
difference of the apparent distance, and difference of apparent
altitudes, and 0.3010300, the log. of 2. Then, to the natural
number corresponding to the sum of these four logarithms,
add the natural verse sine of the difference of true altitudes,
and the sum will be the natural verse sine of the true distance.
. Or, having obtained the natural number, as directed
above, subtract it from the natural cosine of the difference of
the true altitudes, and the remainder will be the naturs^
cosine of the true distance.

136 Astronomical and Nautical Collection,

Example.

(From page 1 12, Appendix to Requisite Tables.)

Reserved log. from Tables (Req.) 9th and 11th . . 9.9938860
Jjog. sin. 43° 23' 5" = i sum of app. dist. and diff.

app. altitudes . 9.8368895

Lo^. sin. 6° 45' 36" = I diff. ditto ditto 9.0708157

Log. of 2 0.3010300

Nat. num. to sum of 4 logarithms . . .1594488 9.2026212
Nat.vers.37° 13' 12"=diff. true altitudes .2036812

Nat. vers. 50° 26' 28" = true distance .3631300

. Or, Nat. cos. 37° 13' 12" =r diff. true altitudes .7963188
Nat. number found above 1594488

Nat. cosin. 50° 26' 28" = true distance . .6368700

Demonstration of the Rule.

Let M\ S\ D', d' and ikf, Sy D, c?, respectively denote the true
and apparent altitudes, distances, and differences of true and appa-
rent altitudes of the moon and sun (or a star) ; then will the theorem
answering to the above rule be expressed by

vers. D' = ^ ^Q^^^^Q^ -^f' sin J- (D+£^)sinl(D-cZ)+Yers.cZ',
cosMcos -S 2 2^- ^

By Bonnycastle's Trig. p. 175, the cosine of the angle contained

, ,, ,^., J . cos D—sin ikf sin 5> cos D' — sin M' sin S'

bytheco-altitudesis. = ;

cos M cos ^ cos M' cos S'

consequently the verse sine of the same angle

_ cos D — sin ilf sin *S , cos D'— sin JW'sin -S ,, . .
Et: 1— =1-- ; that is,

cos M cos -S cos ikf' cos -S'

cosMcosS+sinMsin-S— cosD__cos7kf'cos8'+sinM'sin-S'— cosD'
cos M cos S cos M' cos S'

Substituting cos d and cos d' for cos M cos S + sin M sin S and
cos M' cos S' + sin M' sin S'. (Bon. Trig. p. 282), we have
cos J -cos J) ^ 2^:Z^2lE; whence
cos M cos S cosM' cos. S'

T\i J' cos M' cos 8' X , rk\ u* I,- ii

cos U = cosa (cos a — cosD); or, which is the same,

cos M cos -S'

cos D'= cos d— (versD— verse?); or,(Bon.Trig.p.286.)

cos M cos <S

Astronomical and Nautical Collections. 137

C082y==co9d'-^2?it££l^(2 8in«i.I)--2sm«i.df;) that is,
cosMcosS 2 2

cos D = cos d — sm- (D+a) sm -{D-^a)\ whence

cos M cos S 2 2

1 T\' J/ I 2 cos 3f' cos S' . 1 /n I ^\ • 1/T\ »\

also vers i) = versa + sm- (D + a) sm -(D— a;.

cos ilf cos 8 2 2

It may be observed, that Requisite Tables 9 — 11, answer loga-
rithmically to 221 S-l — ; and the verse sines, and the cosines

cos Mcos S

can be very readily taken out of the tables in the Appendix. Also
no ambiguity can arise from the application of the rule before given :
for all the arcs concerned in the operation will always be (each of
them) less than a quadrant, except the resulting true distance, which
cannot cause any ambiguity ; and the verse sines are given in the
Appendix, to 126"*.

Example.

(Example 2nd, p. 39, Requisite Tables,)

Reserved log. from Tables 9 and 10 .... 9.995307

Log. sin 62° 45' 56" = Jsumapp.dis. anddiff. app. alts. 9.948971

Log. sin 40 43 31 = J diff. ditto ditto 9.814536

Log. 2 0.301030

Nat. num. corres. .... 1.147741 0.059844
Nat. vers. 22° 48' 16" = diff. true alts. 0.078167

Nat. vers. 103 3 23 = true distance 1.225908

De V Influence des Agens Physiques sur la Vie. Par W. F.
Edwards, D.M., Membre associe de rAcad^mie royale de
Medicine de Paris, Membre de la Soci^te Philomatique,
de la Societe de Medicine de Dublin, &c.

The researches of science among the phenomena of the phy-
sical world have long obtained a high degree of estimation
and interest in general society ; but it is of late years only
that their application to living functions has attracted much
of the attention of the literary world.

The laws which govern the action of animal organs (the
proper department of Physiology) have usually been investi-
gated by the medical profession, to which they especially

138 Dr. Edwards, De V Influence

refer. Now we find that the public take some pains, and
'with reason, to inform themselves upon subjects connected
with physiological knowledge. A well-educated person,
■idisposed to philosophical inquiries, is not merely contented
with the consciousness of living, and the common information
he derives of its means by experience, but he seeks also to
comprehend the relations subsisting between his own organi-
.sation and the matters with which he is surrounded, and
which at once furnish him with nutrition, life, and support,
and assail him with disease and annihilation. His own
instincts and observation, joined to the more learned expe-
rience of his medical advisers, help him through the preca-
rious stages of life, and these may perhaps be sufficient for all
its purposes : and under this impression many will seek to
know no more of the secrets of nature.

But we live in an inquiring and scrutinising age, when the
demand for scientific principles is very generally urgent.
All, therefore, relating to organisation seems of equal interest
with that appertaining to what is termed the physical crea-
tion or inert matter.

Under this impression we have perused the book before us
with great satisfaction, and propose to present our readers
with an analysis of the valuable materials which it contains.
We have some knowledge of Dr. Edwards, a countryman
domiciliated in France, and long resident in Paris. We have
confidence 5n his reports, and highly estimate his philosophi-
cal skill, extensive acquirements, and accuracy of observation,
ranking him among the first physiologists of the age.

The work, now under consideration, contains an elaborate
account of a long series of experiments, instituted for the
purpose of ascertaining the influence of the physical agents
upon animal life. These agents comprehend the atmospheric
air, water, and temperature ; the two first constituting the
media in which all animals exist, and the last influencing in
common the inhabitants of both media. It is true, this is a
subject by no means new, for it has engaged the attention
of experimenters from the earliest days of science. But Dr.
Edwards has diligently and patiently sought to investigate
the subject himself, to correct previous errors, and to embody
the facts which he has accumulated into a more complete
and regular system than heretofore adopted. In this attempt
he has been eminently successful, and has efl'ected more
perhaps than all who preceded him, availing himself, never-
theless, of the experience of former inquiries.
- The extent of his book, atid the number of the experiments^

des Agens Physiques sur la Vie. 133

are indeed somewhat appalling, but his clear ^nd distinct
metliod of arrangement greatly facilitates the reader's endea-
vours to master the extensive subjects of his pages. As a
book of reference it should find a place in the library of
every scientific society, and no individual devoted to philo-
sophy should omit the possession of it.

The agency of the air around us, water, and heat and
cold, have often been the objects of chemical inquiry, from
their known great influence upon the animal economy. The
changes effected by the phenomena of animal life upon these
agents liave been accurately examined, and partly reduced
to a mathematical precision of calculation.

Spallanzani and others have viewed the subject as it
regards physiology, but with such results as left the field
open to subsequent investigation. Dr. Edwards seems ta
have seized upon the deficiencies of his predecessors, andy
by going over their ground, and extending his own in-
quiries, he has arrived at most interesting and important
results. These he has divided into four parts, as they relate
to the different orders of the animal creation. The first part
includes some of the lower animals, particularly tenacious of
life, and of cold blood, such as frogs, toads, and salamanders*
The second part is devoted to other animals of cold blood,
and of the vertebrated order, as fish, and those reptiles which
include lizards, snakes, and turtles. The third part refers to
warm-blooded animals ; and the fourth part of the work i^
dedicated to the influence of the physical agents upon thei
human race and vertebrated animals. To these the author
has added the discoveries of modern times, relative to elec-
tricity on the animal economy, in an Appendix. A collection
of tables is appended to the work, exhibiting the principal
series of his experiments, as they regard the relative influence
of physical agents on the duration of life, and the plienomena
resulting from their mutual action.

The great importance of the four grand divisions of thei
work forbids our hastily reviewing them, and we will endea-
vour to condense so much of the information they contain as
may forward the objects of our analysis. Dr. Edwards thus
announces the arrangement of his work : — ;

" Ces recherches auront done rapport k I'air dans les conditions
de quHtitite, de niouvement et de repos, de densite et de rart'fac-*
tion; a I'eau liquide et a la vapeur aqueuse; a la temperature,
dans ses moditications de degre et de durtje; a la lumiere et ^
Telectricite. Ces causes agissent a la fois sur reconomie aniraale,
Qrdinairem^nt d'uue maoi^re sourde et imperceptible ; et toujours

140 Dr. Edwards, De V Influence

I'impression qu'on re9oit est le rtjsultat de toutes ces actions com*
binees.'*

" Lors meme que, par I'intensite de Tune d'elles, il nous arrive
de distinguer la cause qui nous affecte, I'observation de I'effet se
borne le plus souvent a la sensation, et les autres changemens qui
raccompagnent nous echappent. On conjoit par la que I'obser-
vation la plus attentive des pht^nomenes tels que la nature nous
les presente, ne saurait demeler dans cette combinaison d'actions
Teffet propre a chaque cause, ni reconnaitre des effets qui ne
seraient pas reveles par la sensation.

" II est une m^thode qui regie les conditions exterieures, qui
fait varier celle dont on veut apprt^cier Paction, et qui fait juger,
par la correspondance entre ce changement et celui qui survient
dans I'economie, du rapport de cause et d'effet : c'est la methode
experimentale ; c'est celle que j'ai suivie. Pour en tirer parti il
fallait, d'une part, determiner I'intensite de la cause, d'autre part
celle de I'effet. La physique nous fournit ordinairement les
moyens de remplir la premiere indication."

In the true spirit of philosophical investigation, Dr.
Edwards, in the first place, proceeds to examine the action
of physical agents upon the simplest forms, and least elabo-
rately developed organised beings, extending his inquiries
upwards, in the scale of the animal world, to man, the most
perfect creature, and the ultimate object of all physiological
researches.

The peculiarity of constitution belonging to cold-blooded
reptiles, among which there is so little mutual dependance
of organs, renders these the best tests of the relative and
proportionate influence of the different agents^ the intense
action of which is liable to destroy the more perfect animals ;
and the great development of the nervous system in the
higher orders gives them a wider and more acute range of
sensibility. It is difficult, at all times, and often impossible,
to insulate corporeal functions among the warm-blooded
classes, so as to ascertain the amount and limits of physical
agency. The four classes of vertebrated animals, or such as
are furnished with true spines, afford ample means of com-
parative illustrations; and these departments hav engaged
the author's attention, in order to display the result of the
action of the same agent exercising a uniform influence upon
constitutions very differently constructed. The air, for
example, exercises its influence uniformly upon he four
mentioned classes of vertebrate, and their different families
are similarly exposed to the action of the atmosphere by
respiration.

Curious and interesting as is this eubject, it is singular

de$ Agens Physiques sur la Vie, 141

that, while It was among the first to be noticed, it has been
the latest in producing satisfactory results. Among the
opposing causes of the advancement of knowledge in this
department, the ignorance of our ancestors in chemical
science seems to be the principal. Without chemical aid it
is perfectly useless to attempt the investigation. The com-
position of the air respired must be well understood ; the
different gases must be carefully examined, or the physiolo-
gical inquiry will be darkened and obscured.

Dr. Priestley laid the foundation of our chemical know-
ledge of gases in their relation to respiration ; but some time
elapsed before it was understood in what manner the air
was connected with animal organisation. Oxygen gas, one
of the known constituents of atmospheric air, was Priestley's
discovery, in its effect upon the blood, of converting this
fluid from a dark purple to a bright crimson. Lavoisier
founded a chemical theory upon this discovery of the agency
of air, which was subsequently applied by Goodwin to phy-
siology. The latter author demonstrated, by a series of
excellent and correct experiments, that the exclusion of
atmospheric air produces death in animals, in consequence of
the dark-coloured blood usually circulating in the veins being
prevented from becoming crimsoned. The state in which
any animal may be thus placed, is known by the term
ASPHYXY, and by which is to be understood a deficient or
suspended aerification of the blood, from whatever cause it
may proceed that the atmospheric air is prevented from
access to the blood as it circulates through the lungs.

The great French anatomist, Bichat, pursued this subject
still farther, and published a treatise on Asphyxy. He
sought, by numerous experiments, to determine the threefold
relation of the air to the nervous system, respiration, and the
circulation ; and he arrived at this great and important
conclusion, that the venous or dark blood circulating

THROUGH THE BRAIN, CREATES A CESSATION OF THE FUNC-
TIONS OF THAT ORGAN, AND THAT IN CONSEaUENCE THE

HEART LOSES ITS ACTION. This discovery shows us at
once the direct cause of asphyxy in all its different degrees,
according, in effect, to the vitiated state of the blood from
its deficient or suspended aerification.

Le Gallois also investigated the subject of asphyxy ; and
he found that, when dark blood circulated through the spinal
marrow , the motions of the heart ceased ; and thus he not
only determined the relations of the nervous system to atmos-
pheric air, but also those of the respiration and the circula-

142 Dr. Edwards, De V Influence

tion, explainiilg tlie action of the air upon animals physio-
logically.

In this inquiry warm-blooded animals were almost exclu-
sively referred to.

Spallanzani certainly investigated the action of the air on
animals of cold blood, but less in relation to the three grand
objects of Bichat and Le Gallois ; and Spallanzani had the
misfortune to live in an age when neither chemistry nor
physiology had made such advances as the present age has
produced. '

. Messrs. Humboldt and Provencal have, indeed, supplied
much of this deficiency, by their researches into the respira-
tory functions of fishes. Nevertheless, the ground was still
open, and our author has justly appreciated the extent of
former inquiries, and observed that the phenomena of cold-
blooded animals were too extraordinary to be noticed lightly,
and required much more extensive observation than was
previously bestowed upon them. With this impression, he
proceeded to form an estimate of the comparative influence
of the air and water upon the nervous and muscular systems
of cold-blooded animals, which the singular modifications of
life among reptiles in particular afford ample means of
ascertaining.

We know that these animals possess the extraordinary
property of existing a considerable time after the removal of
the heart, with the free exercise of their senses and of volun-
tary motion, notwithstanding the suppression of the circula-
tion. Dr. Edwards accordingly selected salamanders for his
first investigations, and removed the heart, with the bulb of
the aorta. Two of these were exposed to the free action of
the air, and the other two were submersed in water previously
deprived of air by boiling ; a similar temperature being
maintained in each medium. In four or five hours those
submersed in the non-areated water ceased to be active,
unless irritated, when they still appeared to retain voluntary
power. One died in eight, and the other in nine hours.
The salamanders in air lived from twenty to twenty-six hours
and upwards. These comparisons were frequently repeated,
and upon frogs and toads, with the same results, showing
the experiments in air to be far more favourable to their
existence than with the animals submersed in the water.
Eight hours were about the maximum of the duration of life
among the animals submersed in the water, and twenty-nine
among those exposed to the air; so that, independently of
^respiration, the air is thus proved to be the most proper

de^ A(fens Physiques sur la Vie, 143

Hifedium for the action of their nervous and muscular systems,^
in their insulated state, the respiration and the circulation of
the blood being both suspendea. As a further corroboration
of the superior vivifying property of the air over simple
water, when the same animals were plunged into unaerated
water during a certain time, as soon as they were removed
into the atmosphere, they instantly revived ; and their ner-
vous and muscular systems were acted on according as they
were placed in either medium. Dr. Edwards also confirmed
the observation of Goodwin relative to the effect produced
on the colour of the blood. Properly speaking, the asphyxy
comes on the instant the air is excluded, the shades of dif-
ference in the colour of the blood being referrible to the air
left in the lungs after cessation of respiration.

The next point to determine was the influence of the air
upon the same animals exercising the respiratory function,
and retaining their circulation, compared with those deprived
of these functions.

. The difference of time in the two cases developes the
influence which the general circulation of the blood, free
from aerial contact, exercises upon the nervous system.

To ascertain this point, an equal number of frogs, deprived
of the power to exercise their respiratory and circulating
functions, together with others left entire, were respectively
plunged into disaerated water. At times the difference in
favour of the untouched animals was twenty-four hours in
favour of the duration of life. Similar trials with toads and
salamanders produced the same results. In each case asfhyxy
came on ; but the existence of the animals which lived with-
out the respiration and circulation was much shortened.
Thus the relative powers of life between the sole and insu-
lated action of the nervous system, and its action combined
with the circulation of dark blood, were estimated. The
inference to be deduced, therefore, is, that although disae-
rated blood furnishes but an ephemeral sort of existence, it
nevertheless exercises a comparatively favourable influence
Upon the nervous and muscular systems, since it tends to the
prolongation of the action of these animal functions.

Dr. Edv/ards next proceeds to investigate the phenomena
of asphyxy produced by strangulation, or the mechanical
obstruction to the access of air X6 the lungs, and consequently
to the blood. The same animals were employed. When^
the windpipe was rendered impervious by ligature, the
muscles of the animals seemed to be paralysed directly ; and
though their motions became subsequently revived at times,

144 Dr. Edwards, De V Influence

they never altogether recovered their perfect freedom. As
a comparative illustration, an equal number of frogs were
submersed in water, all of which died in about ten or eleven
hours, while those which were strangled lived from one to
five days. Salamanders continued active longest, and one
did not cease to exist till the eleventh day, although during
this time he was in a complete state of asphyxy from perfect
strangulation.

Dumeril once found that a salamander lived a long time
after decapitation, even when the cicatrix of the wound was
healed so as to stop all access of air to the lungs.

In comparing the effects of strangulation with those of
submersion or drowning, it is to be supposed either that these
animals exist a limited period without the necessity of
the nervous system being in contact with atmospheric air, or
that the air influences their blood through the integuments
of the body. Accordingly Dr. Edwards put this to the test
by making experiments upon cutaneous respiration.

Spallanzani found that the exposure of cold-blooded ani-
mals to the air was attended with exudation of carbon, a
phenomenon similar to that of respiration. There appears,
however, to be some source of error in these experiments, for
Spallanzani removed the lungs, and this operation rendered
the animal liable to the absorption of air and loss of blood.
Dr. Edwards sought to effect the same purpose by a different
and more successful measure. He also confined frogs in vessels
of atmospheric air, and fastened bladders round the head and
neck, tight enough to stop the entrance of air to the lungs.
At the expiration of two hours the air was examined in the
bladder, and it was found to contain an excess of carbonic
acid. The same result was obtained from salamanders. It
appears, therefore, that while air is in contact with the skin,
carbon is given out ; but whether this be the eflect of exhala-
tion merely, or that oxygen is actually absorbed, and carbon
transpired, is a question which led to further inquiries. Dr.
Edwards, therefore, inclosed cold-blooded animals in solid sub^
stances, in order to determine the influence of dark-coloured
blood, free of all external agency, in the production of che-
mical changes, and to observe its sensible eft'ect upon the
nervous system.

In the year 1779 three toads were confined in a box herme-
tically sealed, and so deposited in the Academy of Sciences.
Eighteen months after, the box was opened, and one toad
was found dead. These animals have been found alive in
blocks of coal after an imprisonment of some years, and have

des Agens Physiques sur la Vie. 145

also been sealed up during similar periods without perishing.
Possibly some hole or crevice might have admitted a little
air. But, in Hevissant's experiment of 79, care seems to
have been taken to obviate this suspicion.

Dr. Edwards, however, determined to put the question to
the test. He enclosed ten out of fifteen frogs in thick wooden
boxes, and filled the interstices with plaster, covering them over
with the same substance, the toads lying each in a central
hole or bed. The other five toads were at the same time
submersed in water, and at the expiration of eight hours they
were found to be dead. In sixteen hours more, one toad was
taken from a box and found to be lively, and was reconsigned
to its prison. On the sixteenth day the toads in the boxes
were discovered alive, and thus the fact was established that
these animals can live far longer in a state of asphyxy con-
fined in solid substances, than when submersed in water.
This was confirmed by repeated trials on salamanders, frogs,
and toads. The frogs perished quickest.

Thus an extraordinary fact is established, as regarding
reptiles, since it affords an exception to the general rule that
all animals require a constant supply of fresh air for the
maintenance of their existence.

Similar trials were repeated in sand, and with the same
results.

Dr. Edwards found that although a certain quantity of air
enters the boxes and sand, yet that it is far too little to main-
tain life. His conclusion, therefore, stands, that animals of
the kind employed can live longer in solid substances than in
a limited quantity of dry air.

It remains, however, to be considered in what manner these
animals have their lives extended beyond those exposed to
the action of a body of air. Dr. Edwards supposes the
moisture of the sand to be one cause, since in the dry air the
animals become desiccated, the cutaneous transpiration being
lost in one case, and retained in the other, by the exclusion of
air. A rapid and abundant transpiration from the body,
united with deficiency of air, seems to be a greater cause of
dissolution than confinement in solid substances wherein there
is no waste by transpiration.

The author's inquiries are next directed to the influence of
temperature upon animals of cold blood, and two and forty
experiments are practised upon this subject, from the month
of July to September following, during which period frogs
were submersed in aerated water, with a view of settling the
duration of life, acted on by varieties of temperature. Th^

JULY— OCT. 1827. L

J46 Pr. Edwards, De Vlnflumoe

continuance of life, generally, in these experiments, varied
from one to two hours and twenty-seven minutes. The mean
term of life was pne hour and thirty -seven minutes, as ave-
raged in July, and in September one hour and forty-five
minutes, the two extremes of the seasons approximating the
effects. The duration of the frog's existence was greatest in
the greatest depression of temperature. Thus at ten degrees
the duration of life was more than double what occurred at
sixteen or seventeen degrees, and at zero it was about triple.
As the heat was increased, the duration of life was dimi-
jiished ; at forty-two the frogs died, and in the lowest tem-
perature they lived longest.

It appeared that at zero the frogs did not become stiffened,
but retained their motion, and their resistance to the frozen
state is the cause of the continuance of their existence at a
low temperature. The cause of this resistance is to be found
in their peculiarity of constitution. Toads produced similar
results.

It may be alleged that frogs naturally live in climates at
from forty to forty-two ; but, it is to be observed, that they
are then placed in a situation of liberty to come to the sur-
face of the water to respire when they please ; whereas in
these experiments their respii'ation is limited, fropa their ina-
bility to reach the surface.

Taking a wider range of temperature, Dr. Edwards sought
to ascertain the influence of the seasons. In July and Sep-
tember frogs were found to live from one to two hours and
twenty-seven minutes in aerated water at fifteen and seventeen
degrees. In November they died at the end of more than
double this period, under the same temperature, and all other
circumstances being similar excepting the season. As the
autumn advanced life was prolonged.

To what are we to ascribe the modifications of the seasons ?
Probably to circumstances appertaining to the intensity of
light, to electricity, to temperature, to the pressure of the
atmosphere, to dryness and moisture, &c. ? Such existing
causes naturally suggest themselves. But it appears that little
or no account can be rendered as to pressure, since its varia-
tions were too trifling during the two seasons. Moisture
could not effect an influence, because the experiments were
performed in water. The motion of the air was also obvi-
ated. Of all the suggested modifications temperature alone
acted, and this, as it related to the surrounding air, was ren-
dered ineffectual by artificial temperature. The animals,
therefore, could only be affected as to the temperature of the

des Agens Physiques sur la Fie, 147

seasons bi/ that which preceded the experiments. The modi-
fications of the seasons, therefore, appeared to influence the
cold-blooded animals used in the experhnents in this point of
view only. Accordingly we have this remarkable result,
that the animals lived twice as long in autumn as in the
summer preceding, when plunged in water of equal tempe-
rature. The seasons evidently influence their constitutions,
80 as to extend the duration of life independently of other
causes, that is, from summer to autumn. Dr. Edwards en-
deavoured to ascertain if it proceeds from atmospheric tempe-
rature, and he found that frogs lived in aerated water at ten
degrees, during November, from five or ten to eleven, and
even to forty hours, in some instances, the last term being
about double the duration of life in water of the same degree
in summer. This proves the remarkable dependence of the
frog's life under water, and the temperature of the month
preceding. Two curious facts are thus developed by ex-
periments instituted at difi*erent seasons. First, the influence
of the temperature • of the water in which the animals were
placed ; and secondly, the influence of the temperature of the
air during certain periods preceding the experiments, for
in autumn the duration of life was about double that of
summer, and in winter he found the term to equal autumn,
the temperature of the air being in each comparative expe-
riment artificially raised to the same degree.

It appears from the foregoing experiments that frogs,
toads, and salamanders, exist in water according to its low-
ness of temperature, and that their lives are prolonged bi/
the temperatvre which precedes the experiment being lowered.
It then becomes a question, what are the limits of this influ-
ence ? This is to be ascertained by observing the greatest
duration of life among animals deprived of external air by
submersion in water ; and noticing at the same time all the
favourable circumstances dependent on the concurrent tem-
perature in prolonging life among the cold-blooded animals,

A point relative to the natural history of frogs first pre-
sents itself to our notice. Spallanzani is of opinion that frogs
do not pass the winter under water, but retire in October
from their native rivers into moist sands, in which they make
openings to breathe the air through, called by the Italian
fishermen il respiro delta rana.

M. Bose, and other Frentrh naturalists, found that frogs
retire from October to spring into water, but they give us no
direct proof that they constantly remain submersed. The
presence of the observer may alarm the frogs, and thus pre-

L 2

J 48 Dr. Edwards, De V Influence

vent their putting their heads above the water, so that th&
assertion is but a negative kind of proof that they remain sa
long under the water without coming up to respire, as some
affirm. M. Bose declares he watched frogs approach the
surface at regular periods every day during the winter sea-
son. Under the most favourable circumstances Dr. Edwards
found that frogs could not remain submersed, in winter, more
than two days and a half. Frogs are less active during
winter than at the other seasons, but they never lose their
motion. Were it true, as Spallanzani thinks it is, that thejr
remained so long under water, it is probable that they would
become frozen in winter and die. Spallanzani derives his
opinion from what occurs with fish, forgetting that frogs are
amphibious, and live as well on land as in water ; whereas
fish are limited to a watery medium, and can, therefore, fur-
nish no example.

Dr. Edwards found that frogs, placed in certain quantities
of aerated and non-aerated water of an equal temperature,
lived longest in the former ; but that the difference was not
constant in its results, being often twice as long in one case
as in the other, as to the duration of life.

The next inquiry regarded stagnant water renewed at in-
tervals, and in this the duration of life was prolonged beyond
the term of the last experiments, and even to eight days»
During winter when the temperature was lowest the frogs
remained active, though less so than in spring.

The conclusions to be drawn from these experiments are, that
frogs pass the winter in an animated state in water, not be-
coming stiffened as in ice, and that they need not to approach
the surface of the water in order to respire, provided the
water they inhabit be renewed at intervals; but if the water
be not renewed, or if disaerated water be employed, the frogs
perish.

Considering that these animals are truly amphibious, these
results are very curious ; and it is interesting in a physio-
logical point of view, to know that frogs are able to respire
the air contained in the dense medium of water for an inde-
finite period, and just as easily as they breathe the finer
medium on land.

Respecting the action of aerated water on the skin, the
conclusion drawn seems to be correct, that it must be from
cutaneous absorption that the air contained in the water
promoted the continuance of life in Dr. Edwards's experi-
ments upon this point, since the animals were in a state of
asphyxy regarding respiration by the lungs; and that na

des Agcns Physiques sur la Vie, 149

?iir entered in combination with water was shewn from Dr.
Edwards nei^er having seen water in the lungs^ Therefore,
unless the air acted on the blood through some other organ,
the lives of these animals would be definite and shortened,
even though the water be renewed from time to time, and
their asphyxy would be complete and continued. And since
the skin is the only organ in contact with the air, it ig fair to
conclude that it is the medium of atrial absorption.

When the webs: were examined under water, these mem-
branes indicated the action of air upon their blood-vessels, by
the bright tint of the blood. . i'^ujv/ i-)U\ii. ^iiiol oa boni.-a > .
Spallanzani imagined that frogs petish BOOTierm running
than in stagnant water ; but Dr. Edwards having secured
some of these animals in ten feet of the Seine, whilst others
were simultaneously placed in unrenewed stagnant water ^ he
found the latter did not survive many hours, and the former
lived a long time.

In order to fix the limits of this kind of existence, frogs
were placed in renewed aUrated water, and with a tempera-
ture never forced beyond ten degrees they were found to
live in all seasons of the year ; but when the temperature
was elevated from twelve to fourteen, they died in a few
hours. In running streams they lived longest, and at twelve
degrees they were thus more favourably placed than in stag-
nant water, at a lower temperature even, and taking the pre-
caution to renew the water daily ; and at seventeen degrees
in running water they died prematurely. Toads exhibited
the same comparative results, but they lived the longest.

It appears, therefore, that water contained in vessels is less
favourable to the lives of these animals than running streams,
although the water and the temperature were identical.
Probably the great advantage of running water is its con-
stant and unceasing renewal. The separate and comparative
influence of air, water, and temperature, being thus investi-
gated, the combined action of the three physical agents was
next inquired into, and it is demonstrated that frogs sub-
mersed in water are influenced by three circumstances, — !•
the presence of air in water ; 2. the quantity of its renewal ;
3. the temperature of the medium. If the manners of frogs
be closely examined, they appear to live in water under very
considerable influence from the atmosphere.
■ From circumstances developed in the foregoing experi-
ments, cutaneous respiration seems to be pretty evidently in-
dicated. A chapter is, therefore, devoted to this subject, one
that is not well known, although pulmonary respiration ia

150 . Dr. Edwards, De V Influence

generally understood. In frogs, the function of pulmonary
respiration is united with that of deglutition, and the air
enters only by the nostrils, the mouth being closed during
respiration. While the mouth remains open, the action of
deglutition is stopped, and, therefore, the animal does not
then breathe. Dr. Edwards availed himself of this circum-
stance by gagging the mouth so as to keep it open, and thus
prevent the air from entering the lungs. The frogs were
sufficiently exposed to moisture and renewal of air to their
bodies : the results were, that, at twenty-four degrees, five
frogs so placed died next day, and one lived a week.

Dr. Edwards immersed some frogs in wet sand, and adopted
an improved method of excluding air from the lungs, and
some of them lived twenty days. Hence it evidently appears
that air influences the skin materially, and counterbalances
the asphyxious state induced by obstructing the air's passage
to the lungs. By adopting other methods, the existence of
frogs was prolonged to thirty or forty days. It is, therefore,
sufficiently proved that the blood undergoes its necessary
changes from atmospheric influence through the medium of
the skin, although in a minor degree compared with those
which it passes through from pulmonary respiration. Frogs
are thus shewn to possess a double source of respiration.
. By substituting oil for water, frogs immersed in this fluid
died in a few hours, being at liberty to breath the air on its
surface. And, when plunged into oil, with the means of
breathing by the lungs arrested, they lived an equal time
with frogs simultaneously placed in water without power to
respire. A comparison was instituted with frogs in oil and
in water, being allowed to breathe air, when the differ-
ence was found to be very considerable in favour of the
aquatic bath. These circumstances shew, that, even with
the feeble succour of the air through the skin, absorbed from
the water, the respiratory function was far more prolonged,
than in the case of the obstruction afforded by the oil. Thus
we have abundant evidence of the double function by which
frogs are maintained, from the action of the air on the skin
and the lungs ; and this appears to be the means of existence
among amjihibious animals generally.

It may be asked why these animals die in deep water when
prevented from approaching the surface? It appears that,
having expelled the respired air from their lungs, which is
imperfectly renewed from the water, they become specifically
heavier than the water, and unable to rise from the bottom ;
and thus placed, the duration of their lives depends upon

d^ Agms Physiques sur l^ Vie. 151

the resistance offered by their constitutions to the depressing
effects of a state of asphyxy while remaining submersed.

Dr. Edwards next proceeds to inquire into the effects of
TRANSPIRATION. A liquid transfusion from the skin of
animals is constantly going on, either in the form of vapour
or of fluid in a denser state.

The latter constitutes sweat. This phenomenon exhibits
great variations, and it is important to know what diminu-
tion of weight the body suffers in different circumstances.
In the course of an hour remarkable fluctuations occur.

Dr. Edwards suspended frogs, toads, and salamanders, in
a calm air^ weighed them, and noted the results, which<
though very changeable in an hour, were generally uniform
in three, and in nine hours they averaged an equal result.
The successive diminution in the mass of fluids was evident.

The results were modified by the alternate position of the
animals in a body of air in repose, or agitated by a draft*
And these results do not appear to depend upon any prin*
ciple of vitality, for they take place equally in death and in
life, and indeed among unorganized bodies, as, for example,
lumps of charcoal soaked in water. Therefore the cause of
the phenomenon of transpiration seems to be referribk
entirely to physical agents. The motion of the air seems to
be its exciting cause ; for even when^ to all appearance, it is
calm, it is in reality agitated more or less, and produces a
sensible evaporation from the skin. But the difference
between the effect of calm and agitated air is remarkable i
for in a draft, the animals exposed to it sweated away double
the quantity of liquid compared with those confined in a
room shut up. The amount lost was proportioned to the
intensity of the wind, and reached a triple amount over thosd
animals in stagnant air ; and this fact explains the variations
noticed from hour to hour among animals exposed to currents
of air. :

The transpiration which occurs in very moist air, always
amounts to a diminution of weight ; but in dry air it is five
or ten times greater ; and when the influence of a moist state
of the atmosphere is compared with that of a dry state, the
amount of evaporation is equal to that of a dry and calm air»

Transpiration may, therefore, be referred to the agitation
of the atmosphere for its exciting cause, beyond any modifii
cations of its density. And, although an elevated tempera-
ture be favourable to transpiration, its modifying influence
is less than that of other causes.

In comparing the effects of absorption and transpirationi

152 Dr. Edwards, De VInflumce

in water and in air, frogs were found to gain an addition to
their weiglit according to the term of their continuance in
the former medium. An absorption of water was rendered
evident by the loss of bulk it had sustained, when measured
after the experiment.

Thus, when the comparative influence of water and air is
estimated, the former appears to be absorbed, and adds to
the weight of the body ; and the latter tends to diminish the
weight, by different and fluctuating degrees of evaporation
taking place, and dependent much more on the degree of
motion in the air, than on its dryness or humidity : these last
conditions modify evaporation in a minor degree, when com-
pared with the influence of a current of air.

The celerity of abswption exceeds that of transpiration six
times, in the most rapid cases. It therefore results, that the
losses by transpiration in air should be repaid by absorption
of water in a much less time than the expenditure occurs.
But the decrease of weight is not prolonged ; it is sudden,
and not continuous, alternating with augmentation of weight,
by absorption of liquid going on in a ratio superior to the
loss ; and thus nature's provision is manifested for the nutri-
ment of the body.

With this last inquiry Dr. Edwards concludes the first
part of his work ; and it is observed, that, with regard to
transpiration, the losses of weight have been considered with-
out reference to the existence of any other influence than
water. The losses by transpiration have been examined
generally without regard to the matters lost. What relates
to water difi*ers essentially in one respect from that which
regards the air. The losses sustained by the body ought to
be more particularly examined. Temperature and loss of
time require estimation. An excretion of solid matter evi-
dently takes place ; for the water, in which animals are
submersed, becomes turbid, especially in hot weather, and it
sensibly contains animal matters, afiecting the weight of the
body in water.

When animals are submersed in water, their skins exercise
two functions, acting inversely in determining their weight.
And it results, from comparative experiments, that the
absorptio7i at zero exceeds the loss in water ; while at thirty
degrees the loss exceeds the increase by weight from absorp-
tion ; and the higher the temperature, the greater is the
excess in the discharge of animal matters. We may therefore
presume, that the agency of temperature produces analogous
effects, upon aerial transpiration, to those before observed

des Agens Physiques sur la Vie^ 158

in other inquiries; and the effects of dryness and moisture
in the air produce a minor degree of influence also, when
compared with temperature y on the losses of animal substances.

We have been thus minute in our analysis, because the
subject of it is new to science in its present shape, and of a
high degree of interest. Dr. Edwards's researches among
the difierent classes of animals have tended more to the
illustration of the influence of physical agents upon life than
any previous authorities ; and the persevering industry,
accuracy of observation, and patient inquiry which he has
evinced in his investigations among cold-blooded animals,
have placed this department of the creation in a point of
view at once curious, interesting, and valuable to science.
We attach the greater importance to this part of the author's
work, as it is a ground on which he may be consulted, and
quoted as indisputable authority, until equal inquiries havQ
shewn him to be fallacious.

Our limits will not at present permit us to proceed farther
in our analysis, and we must refer the remainder of the book
to a future opportunity. The subjects of the three other
parts, though greatly extended, will not probably require
such minute analysis as those novel experiments which form
the subject of the first part ; but we imagine that the appli-
cation of the principles laid down^ in the previous inquiries,
to human physiology, will be found not less interesting than
those which relate to the natural history of the lower orders
of the animal creation.

An Account of Professor Carlini's Pendulum Experiments on
,^yj^ , Mont Cenis.

W^ believe that no account of Professor Carlini's pendulum
experiments on Mont Cenis has hitherto appeared in the peri-
odical scientific publications of this country : the experiments
are, however, well deserving of such notice, having been con-
ducted with great care, and having had a specific object in
vie^, which object seems to have been satisfactorily accom-
plished. The following brief account of them, taken from the
original memoir published in the Appendix to the "Eph6m6ride
di Milano " for 1824, may not be unacceptable to those of our
readers who interest themselves in subjects of this class.
'- The length of tRe simple pendulum vibrating seconds is a

154 • Aecount of Professor Carlini's

measure of the intensity of gravitation ; i. e. of the excess of
the force of gravity over the centrifugal force. In consequence
of the ellipticity of the earth, and of the difference in the
direction of the two forces, the intensity of gravitation varies
according to the different latitudes. It also varies, in the same
latitude, according to the greater or less elevation of the pen-
dulum above the level of the sea ; i. e. according to its greater
or less distance from the centre of the attracting force, foa '^Blt

Had the earth a perfectly level surface, such, for instance,
as it would have if it were everywhere covered by a fluid, the
force of gravity, in receding from the surface, would diminish
in the duplicate proportion of the distance from the earth's
centre. In the actual state of the globe, however, its conti-
nents and its islands are raised above the general level of the
sea by which it is only partially covered ; and if a pendulum
be raised, on the surface of the land, to a known elevation
above the sea, the diminution of gravity will not be, as in the
more simple case, proportioned to the squares of the respective
distances from the earth's centre, but that proportion will
require to be modified, by taking into account the attraction of
the elevated materials, interposed between the general surface
and the place of observation.

When pendulums are employed in different latitudes, to
obtain the ratio of gravitation between the equator and the pole,
for the purpose of deducing the ellipticity of the earth, all the
places of observation, being on land, are more or less elevated
above the sea; inland stations, in particular, are sometimes at
considerable elevations: to render these results comparable
one with another, it is necessary to reduce each result to what
it would have been, had it been made at some level common to
all the experiments ; and the surface of the sea has hitherto
been taken as that common level. Previous to the publication
of a paper of Dr. Young's in the Philosophical Transactions
for 1819, the consideration which we have mentioned, that of
the attraction of the matter interposed between the place of
observation and the level of the sea, was generally unheeded
in estimating the allowance to be made for the reduction of
different heights to the common level : in that paper, however.
Dr. Young took occasion to point out the probable effect of

Pendulum Experiments on Mont Cenis. 155

the interposed matter in modifying considerably the usual
allowance ; that, supposing its density to be about half the mean
density of the earth, the effect of an hemispherical hill of such
matter, on the summit of which the pendulum should be placed,
would be to diminish the correction, deduced from the dupli-
cate proportion from the earth's centre, about ^th; that, in
like manner, a tract of table-land, considered as an extensive
flat surface, of the same relative density, would diminish the
correction about ^ths ; and that, accordingly, in almost any
country that could be chosen for the experiment, the proper
correction for the height would vary, according to the form
and density of the interposed materials, from rather more than
a half to rather less than three-quarters of the usual allowance*
This view has been subsequently acted upon by the English
pendulum experimentors, in reducing their observations ; but
it has not been yet adopted by the French. The experiments
of Professor Carlini were calculated to afford a practical illus--
tration of the correctness of Dr. Young's reasoning.

Professor Carlini was engaged, in the summer of 1821, in
concert with Professor Plana, in determining the amplitude of
the celestial arc between the Hospice on Mont Cenis and the
Observatory at Milan, by means of fire-signals made on the
Roche Melon, and observed simultaneously at Milan and at a
temporary observatory established at the Hospice. Whilst
thus engaged, Professor Carlini, being stationary for several
days on Mont Cenis, and obliged to have time very accurately
determined, for the purpose of comparing with the observatory
at Milan, availed himself of the opportunity to employ a pen^
dulum apparatus of the same general nature as that used by
M. Biot at Paris, which had been prepared at Milan some
years before, under the direction of a commission of weights
and measures^ with the view of determining the value of the
divisions of the national Unear scale. As this apparatus dif-
fered in some few particulars from the original employed in
France^ we shall briefly notice the differences, presuming our
readers to be acquainted with the apparatus of MM. Borda
and Biot. KWiivwtijB -.jiii ^miJj.

1. In the Milan apparatus, by Witsans'df twO' mTCrOscopes
(urnished with wire micrometers, the length of the pendulum.

156 Account of Professor Carlini's

may be measured without touching it ; -without approaching
it; without even opening the case \vhich contains it. > The
measure is obtained by bringing the wires in contact with the
images of the knife-edge suspension, and of the upper and
lower borders alternately of the platinum disk suspended to
the thread: thus preventing the risk of deranging the equi-
librium, and avoiding the effect which the heat of the body
might have on the very dilatable metallic threads ;ri J is 93n'>2C1i

2. The half sum of the distances taken betweeri the stts-
pension, and the upper and lower edges of the disk, gives the
distance of the centre of the disk itself, without measuring its
diameter with a compass, an operation exceedingly difficult to
execute with the necessary precision. By this apparatus of
microscopes the length may be measured at pleasure, even
during the time of oscillation ; and being attached to the wall,
instead of supported by the floor, the risk of derangement by
the tread of the observer is avoided. : n.nn )f->!

3. The pendulum, and the clock by which its oscilktions
are measured, were not, as usually, near together and resting
on the same base, but were perfectly separated. The coinci-
dences of the oscillations were observed, by bringing the image
of the pendulum of the clock, reflected by means of an oblique
mirror, in contact with the image of the simple pendulum seen
direct through a telescope. By this modification the risk of
the mutual influence of the pendulum and the clock is avoided.

4. The disk was attached to the thread by means of knots
in the thread itself; avoiding the correction for the small cup
usually employed for that purpose.

5. An alteration was made in the weight and shape of the
knife-edge suspension ; reducing its weight to about 10 grains,
and giving it the shape of a rotella, instead of that of a triangu-
lar prism.

The simple pendulum and microscopes were attached to a
strong wall, in a room on the ground floor, contiguous to the
temporary observatory, and well sheltered from the sun and wea-
ther. The clock with which the pendulum was compared, was
supported by a pyramid of masonry resting on the ground, and
occupying the middle of the room. The experimental length
between the microscopes was referred to three standard metres^

Pendulum Experiments on Mont Cenis^ 157

in perfect agreement with each other : one received from Paris
by the Commission of Weights and Measures at Milan; a
second brought more recently from Paris by Conte Moscati ;
and a • tfl^ird - in .the i;possessioa; of the Royal Academy of
TuriDJ'M-xj^ii ' .i'il ;^-.! , ;,■:,.

•I'^'be «itperiiQents were commenced on the 3rd of September,
add'terminated on the 27th, being interrupted by M. Carlini's
absence at Chambery from the 7th to the 12th. The distance
between the microscopes, and the oscillations and length of the
pendulum, were measured alternately. Thirteen independent
results were thus obtained, of which the greatest discordance
from the mean was not more than -jyV^T)^^^ ^^ ^ British inch.
The mean result was 39.0992 British inches, the length of the
pendulum vibrating seconds in a vacuum, at the place of obser-
vation on Moiit Cenis, 1943 metres, or 6374 feet above the
sea, in the latitude of 45° 14' 10". To compare with this
determination, we may obtain a tolerably fair approximation
tO' the pendulum at the level of the sea in the latitude of
45° 14' 10", such as its length might have been found, if the
mountain could have been removed and the pendulum placed
on its site, by deduction from the lengths actually measured
with a similar apparatus, on the arc between Formentera and
Dunkirk, at stations not far removed from the level of the sea,
in the adjacent parallels to Mont Cenis, and in the countries
adjoining. Of these there are five, not including the station at
Clermont, in consequence of its great elevation : they are as
follows : —

Dunkirk .. 51 02 10; its pendulum at the level of ihe seat — 59.13771
Paris ... 48 50 14; „ „ „ „ 39.12894

Bordeaux . 44 50 26 ; „ ^^^ to offf>'l^ 5iij» ar..^^-^^^^^

Figeac ... 44 36 45; „ ^ ,T ' ^"^2. ^"39.11212

Formentera 38 39 56; „ ,» ., „ -r^ 39.09176

The mean length of the seconds pendulum at the level of the
sea, in the latitude of 45° 14' 10^, deduced from these deter-
minations, is 39.1154 ; and it is so equally, whether an eUip-
ticityof^th, or of ^^th, or any intermediate ellipticity, be
assumed in the reduction.
We have, then, 39.1154 - 39.0992 = -0162 inch., as the

158 Account of Professor Carlini's

measure of the difF^ence in the intensity of gravitation at the
place of observation elevated 1943 metres, and at the level
of the sea. The radius of the earth being 6,376,478 metres,
this measure, according to the duplicate proportion of the
distances from the earth's centre, should be *0238 inch. The
attraction of the mountain is, then, equal to -0238 — '0162 =
•0076 inch. Whence it appears that, in this particular instance,
the correction for the elevation is reduced, by the attraction of
the interposed matter, to -j^^ths, or to about ^ths of the
amount immediately deducible from the squares of the dis^
tances.

It is obvious that, if we possessed a correct knowledge of the
density and arrangement of the materials of which Mont Cenis
is composed, so as to enable a computation of the sum of all
the attractions which they exercise on the place of observation,
this result might furnish, as well as Dr. Maskelyne's experi^
ments on the deviation of the plumb-line produced by the
attraction of Mount Schehallien, a certain determination of thei
mean density of the earth. Professor Carlini considers that
the form of the eminence may be sufficiently represented by a
segment of a sphere, a geographical mile in height, having as
its base a circle of 11 miles diameter, the distance from Susa
to Lansleburgo ; the attractive force, on a point placed on the
summit, would, in such case, be equal to 2 'r ^ (1— f^ -^)^
or in numbers to 5 -020 J, ^ being the density of the mountain,
and 2 ir the ratio of the circumference to radius. The
attractive force of the earth, on a point at its surface, is f tt r A ,
= 14394 A J r being the radius of the earth =r 3437 geogra-
phical miles, and a its mean density. Now these two quan-
tities, 14394 A and 5 ♦ 020 ^, should be, to each other, in the
proportion of 39.1] 54, — ^the pendulum at the level of the sea,
representing gravitation at the surface of the earth, — to -0076,
the portion of gravitation at the summit of the mountain due
to the attraction of the mountain. By the observations of M„
de Saussure and other geologists, Mont Cenis is chiefly com-
posed of schistus, marble, and gypsum ; the specific gravities
of which substances were ascertained, from numerous speci-
mens in the possession of M. Carlini, to be respectively as
follows : —

Pendulum Experiments on Mont Cents* 159

Theschistua . . . 2-81.
The marble . . . 2-86.
The gypsum . . . 2.32.

In the absence of a precise knowledge of the quantity and
position of each of these three component parts, we may take
the mean, 2.66, of their several densities as approximatively

the density of the mountain, = ^. We have then
• ■} nov •

•rft ^o ^ ^ 5 .02^x39.1154 ^ . „^

" 14394 X- 0076 ' *

a result differing little from that of Cavendish as recently cor-
rected by Dr. Hutton, and still less from that of the Schehallien
experiments.

The most hypothetical element of this calculation is the
width assigned to the base of the mountain ; but by the very
nature of the question, it has but little influence on the final
result ; since, by even doubling the assigned diameter, the total
attraction would not be altered a twentieth. In regard to the
mean density of the mountain, if it were taken at 2.75, instead
of 2.66, that of the earth would result 4.94, instead of 4.77, as
given above.

E. S.

Transactions of the Horticultural Society . Vol. vii. Part 1.
4to. London, 1827. pp. 208.

I. Observations upon the Growth of Early and Late Grapes under
Glass. By Mr. James Aeon.

Few gardens are to be found in which bunches of fresh ripe
grapes can be gathered every day in the year : notwith-
standing the importance of the fruit to the luxurious, and
the facility with which the vine submits to the artificial cli-
mate of the forcing-house. Nothing is easier than to secure
crops of grapes in a vinery during the spring and summer
months ; but it is far more difficult to obtain them in the
last and earliest seasons of the year, when the plants would

160 Transactions of the

naturally be in a, state of torpidity. It is well known that
this desirable purpose is attained In great perfection in the
garden of the Earl of Surrey, at Worksop Manor ; and the
management there practised is the subject of this paper.

The common methods of forcing early grapes are to train
the vines under the roof near the glass, or on small frames
against jQued walls; but to both these practices Mr. Aeon
finds great objections : to the former because it renders the
house too dark, and exposes the young and tender branches
to the pernicious effect of blasts of cold air rushing through
the interstices of the panes ; and to the latter, because the
heat of the flues is apt to scorch the branches, and in conse-
quence to destroy the crop, — excessive heat in the one case
producing the same injurious effects as excessive cold in the
other. The following are the two modes by which Mr. Aeon
obtains his iwri/ early and his veri/ late grapes. For the early
crops a house is used, of which the back wall is 9.6 feet In
height, and the front wall 3 feet, the roof forming an angle
of about 30 degrees. It is heated, from the absolute neces-
sity of employing an atmosphere of unusually high tem-
perature, with two flues that pass along the middle of the
house, and return in the back wall ; a flre-place being
built at each end of the house. Forcing begins on the first
of September, and the fruit begins to ripen the first week
in March. The vines are trained upon a trellis, fixed over
the flues, in the centre of the house, and also upon the back
wall ; but none are allowed to obstruct the light by occu-
pying the roof, until about six weeks after the forcing has
commenced, when some new shoots are introduced and
trained to the rafters. The form of this house gives it a
peculiar advantage, in presenting a greater surface for the
growth of vines than can be derived from any other plan ;
the trellis which is placed over the flues is nearly equal to
the whole roof, without being in any degree injurious to the
plants trained upon the back wall. The vines are planted
in the inside of the house, but in such a manner that the
mould in which they grow is not heated by the fire-places of
either flue. The usual mode of exposing the main stem of,
a forced vine to an extremely low temperature in the exter-
nal air, while the branches are stimulated by a very high
temperature in an entirely different atmosphere, is very pro-
perly objected to. Nothing, In fact, can be more injudicious
than such a practice, in cases where very early forcing Is
required ; for it should be borne in mind, that although the
absorption of the elements by which the proper juices of a

Horticultural Society of London, 161

plant are elaborated, and brought into the state under which
they appear in the fruit, and in the secretions of the plant, is
carried on by the leaves alone, yet that all these juices have,
in the first instance, to pass along the vessels of the stem
before they reach the leaves ; and that the whole of the bark
of a tree is, rightly considered, a leaf of a particular de-
scription, formed of the same kind of tissue, and exercising
the same functions, and undoubtedly producing a powerful
effect upon the motion of the fluids of the branches, with the
vessels of which it is elaborately and intimately entangled,
from the core to the circumference. No argument can be
necessary to show that an equal action of the vessels of a
plant is indispensable to the due maintenance of the vegetable
functions in a healthy state, and that this is not to be main-
tained by exposing the main stem and the extremities to an
atmosphere and temperature entirely different. Such irre-
gularities do not exist in free Nature, and she will not sub-
mit to them when in fetters.

In pruning vines for early forcing, as little wood should
be employed as possible. Mr. Aeon stops the shoots one
joint above each cluster, and has no joint without a bunch.
When the crop is over, and the wood perfectly matured,
the branches should be laid near the ground, and shaded
till the recommencement of forcing. In short, they should
be placed in a condition as nearly as possible resembling
the gloom and cold of winter. If this process be well ma-
naged, the vines will alter their natural habits, and instead
of budding with the spring, their vegetation will naturally
commence at the period at which they have been accus-
tomed to be stimulated.

For late grapes, a house of a different construction is em*-
ployed. The back wall is 12 feet high, the front wall IJ
foot, and the roof lies at an angle of 45 degrees. The heat
is supplied by a single flue passing along the middle of the
house. The sorts best adapted for late forcing are the Mus-
cat of Alexandria, the St. Peter's, and the Black Damascus;
all other kinds wither prematurely. This house is generally
shut about the middle or end of May, as soon as the bunches
become visible. The vines are trained on a trellis near the
glass. Till ihey are out of blossom the air is kept very
warm, a point to which much importance attaches, because
it is during this period that all the branches that are to bear
fruit in the sticceeding season are produced. In a high
temperature, the branches will grow more compactly, and

JULY — OCT. 1827. M

162 Transactions of the

will be more regularly matured than in a low temperature^
in which the wood is apt to become excessively luxuriant, and
not to ripen well. Great attention must be paid to this
point. As much air as possible is introduced into the vinery
during the summer ; but as the autumn advances, more
caution in this respect is observed. The fruit should be
perfectly coloured at the approach of the dark season ;
for if the colouring be deferred too long, the berries will
never acquire their proper flavour. Great care must be obr
served to remove daily such berries as are inclining to damp,
or the whole crop will soon be spoiled. This should be par-
ticularly attended to ; for the contagion of what gardeners
call damp, arises from the growth of minute fungi which
vegetate upon the epidermis, and spread during the autumn
with alarming rapidity from bunch to bunch.

The pruning of vines for late forcing is the same as has
been already explained. When the crop is gathered, the
house is unroofed for a short time, in order to expose th^
branches to a low temperature, and to the degree of humi-
dity necessary to replenish their vessels, which have been
drained by the dryness of the climate in which, when forced^
they were necessarily kept.

By the means above described, a regular supply of grapes
is secured through the year. The late-house crop lasts
from the middle of January to the end of March ; it is suc-
ceeded by the first crop in the early-house, which carries on
the supply into May, and it is continued by the grapes on
the rafters in the same house until the vines in the pine
stoves, which are forced early in January and February,
produce their crops. These continue bearing through the
summer, when a vinery, of which the forcing commences
about the end of March, furnishes the supply till the late-
house fruit is ready in January.

Upon the whole this may be considered a most instructive
and valuable communication.

II, On the Varieties of Cardoon, and the Methods of cultivating them.
By Mr. A. Mathews,

Who does not wish to read of the cardoon ; of that prince
of vegetables, whose praises have been sung or said by all
cooks and gourmands, from the fastidious Perigords and
Cardellis of the French cuisine, down to the more homely
Rundells and Glasses of our English kitchens ; whose virtues
are so marvellous as to be credible upon no less authority

Horticultural Society of London, 163

than that of the sage gastrophilists aforesaid. To restore
unwonted vigour to old age, and new elasticity to youth,
are the most modest of its attributes ; the magical broth with
which the veins of iEson were replenished by the cunning
Medea, was doubtless prepared from the cardoon ; and the
story itself is probably a sort of figurative record of the skill
of the fair enchantress in cooking this delicious vegetable,
which was well known to the Grecian gastronomes under
the name of xaxros- ; but this we throw out merely
as a suggestion. Upon preparing herbs thus potent for
the table, cookery has exhausted all its skill ; to dress a car-
doon is declared, by the highest authority in the art, to be
the surest test of a skilful cook ; and one of those invaluable
acquirements which, to borrow the words of a writer not
less celebrated for his powers of composition than of cook-
ing, *^ raises cookery to the rank of the sciences, and its
professors to the title of artists." Our good forefathers,
indeed, *' could not find the true manner of dressing car-
doons,"" and were content to eat them raw " with vinegar
and oyl, pepper and salt, all of them, or some, as every one
liketh for tneir delight;" which, considering that this vege-
table is both bitter and astringent in a high degree, does not
argue much for the delicacy of palate of our ancestors ; little
did they dream of the savoury preparations that modern art
has devised by the aid of Espagnole, consomm^, blancs, tam-
mies, marking, masking, and all the mysteries of the stew-
pan.

Four varieties are here described, of which the Spanish
cardoon is the most common, and the cardon de Tours
the best.

They are cultivated, like celery, in deep broad trenches,
well manured and watered. When the plants are nearly
full-grown, which will be about the end of October, a dry
day is to be chosen for performing the operation of blanching
them, which is thus effected : —

** The leaves of each plant are carefully and lightly tied
together with strong matting, keeping the whole upright,
and the ribs of the leaves together. The plant is then bound
closely round with twisted haybands, about an inch and a
half in diameter, beginning at the root, and continuing to
about two-tliirds of its height. If the plants are intended for
winter store, they must be earthed up like celery ; but if to
be consumed before the frosts set in, the operation of earthing
UP ra^y be omitted."

M 2

164 Transactions of the

III. Accounts and Descriptions of the several Plants belonging to the
genus Hoya, which are cultivated in the garden of the Horticultural
Society at Chiswick. By Mr. James Traill.

The beauty of one species of Hoya, viz., H. carnosa, has
long caused it to be a favourite with collectors. The object
of the writer of this paper is to call attention to such othei's
as are known to exist in garden^, or as'a^^^^
records of the botanist. \ V - .

The following species form the subject of the paper, viz. :

1 Hoya carnosa, R, Brown. 2 Hoya crassifolia, Ha-
"Worth, 3 Hoya pallida, Lindley. 4 Hoya Pottsii, (Tab. I.)
5 Hoya trinervis.

These five are all the species at present cultivated in gar-
dens ; ethers are known to exist in the v/armer regions of
Asia, where they should be assiduously sought for by tra-
vellers, as they are not only very ornamental, but also easily
to be transported to Europe. ^ ^

From such materials as he has been able to procufe^ , the
\vriter enumerates the following as completing the genus
Hoya, as far as at present ascertained :

6 Hoya chinensis. 7 Hoya viridiflora, R. Brown, 8
Hoya lanceolata, D. Don. 9 Hoya linearis, D. Don,
10 Hoya australis, R. Brown, MSS. 11 Hoya nicobarica,
R. Brown, MSS. 12 Hoya augustifolia.

The paper concludes with a detailed explanation fOif^ the
best manner of cultivating ^oy^^f ';;^^^iia't^n9^^^^

XV. On acclimatizing Plants at Biel,in East Lothian. ' By Mr. Jonjti
Street, gardener to the Honourable Mrs. Hamilton Nesbitt. '"',^

Perhaps there is no point whatever, connected with Horti-
culture, of greater interest than that which forms the subject
of this paper ; it is the distant goal towards which we all are
striving, but of which, alas I we have not as yet even caught
a glimpse. The gardener is in possession of the powers by
which lie can bend the seasons to his will ; he can dispel the
frozen gloom of winter with the rich warm glow of the vin-
tage ; at his call the flowers of spring and summer start up be-
neath liis feet, and his hothouses are filled with the luscious
fruits of the torrid zone. All this he knows how to effect
with an artificial climate ; but he has no influence over the
natural climate of his country, nor can he impart to the
vegetation of warmer latitudes the least additional power of
resisting cold, for which they have not been prepared hy
nature. Acclimatizing is still a secret to be discovered. To

HorticuHural Sodiety of London. IBS'

this day not a single instance can be adduced of any exotia
plant whatever possessing greater {^oivers of withstanding
cold, than it ha4 when first introduced. It has been hoped
thatji'fth^ seed^ of a given plant could be procured, for
many generations, in a climate severer than its own, the
offspring so obtained would gradually accommodate them-
selves to their new country ; but no such result has followed
from the experiments that have been tried. Let ua take a
fey?" familiar examples: — the common nasturtium, (Tropae-
luhi majus,^ a native of Peru, is said to have been intror
duced about the year 1686. At the time at which we are
writing, it must have descended through about 140 genera-
tions; and yet it has not become in the smallest degree
capable of resisting cold. Of the mignonette (Reseda odo-
rata), the date of introduction is not well ascertained ; it
has probably been a favourite border annual for sixty or
seventy years, and yet it has in no degree shaken off its annual
character, which is unnatural to it, and resumed the suffru-
tescent habit which it possesses in its own milder climate.
The potato, too, which has for two centuries and a half
been increased in every conceivable manner, by seeds as
well as by offsets, bears cold in no degree more readily
than it did in the sixteenth century. Nor does it appear to
us probable, that acclimatizing, if practicable, is to be
brought about by sowing seeds in northern latitudes through
successive generations. We do not believe that plants will
bear their seeds at all in a temperature much lower than
that in which they have been located by the hand of Nature.
The heat of a northern summer sufficiently approximates to
that of the tropics, to be considered, with reference to vege-
tation, as the same, and it is during that season that the
seeds of all plants are ripened ; the conditions, therefore,
under which the seeds of Tropaeolum, for example, are pro-
duced in England, do not materially differ from those under
Which the same seeds are produceu in Peru ; if the season
proves unpropitious in any considerable degree, they are not
produced at all. How then can it be expected that seeds
ripened under similar circumstances, but in different lati-
tudes, should give birth to a progeny differing in any re-
ma^'kable particular from their parents ? In fact, in power of
reslstlhg coW, they do not differ at all. If such a capability
were l^o be obtained, it would be by inducing plants to ripen
their seeSs in winter.

But if it is certain that nothing is to be gained in acclima-
tiring, by raising plants from eeed through successive gene^.

166 Transactions of the

rations, it is no less true tnkt many trees, which have been
supposed to be incapable of surviving a northern winter, are
now ascertained to be perfectly hardy, and that the power
of enduring cold may be increased in others, by a judicious
management of soil and situation., , U ^ t)j-;iL-iMV lu

The phenomenon of vegetable liSfe being destrbyea by
cold, probably arises from the vessels, through which the
circulation and secretion of the fluids of plants take place,
being ruptured by the expansion, from cold, of tlie fluid they
contain. In proportion, therefore, to the tenuity of the ves-
sels, and the abundance of their fluid, will be the danger to
which they are exposed from frost ; and to the strength of the
vessels, and the paucity of their fluid, the power of resisting
eold. Thus vigorous shoots of the oak, walnut, and many
other trees, which are formed with rapidity, imperfectly ma-
tured, and highly charged with fluid, are extremely impa-
tient of cold, and are even destroyed by a few degrees of
frost ; while the twigs and branches of the same trees, which
are formed slowly, fully matured, and incompletely flUed
with fluid, bear unharmed the utmost rigour of our winters.
In acclimatizing, therefore, this law should be carefully
remembered, and the situations in which tender plants are
stationed, should be those in which their growth is re-
strained^ and an excessive absorption of fluid prevented.

This appears to have been the true secret of the success
that has attended the attempts at acchmatizing, which form
the subject of Mr. Street's communication. By planting in
situations well drained from superfluous moisture, under cir-
cumstances where rapid growth was rendered impracticable,
and, as we understand, in a garden admirably adapted to
the object, from its position, he has succeeded in natura-
lizing, in latitude 56° N., plants which have not yet been
known to endure the winters even of the parallel of London.

V. Upon the Culture of Celery. By Thomas Andrew Knight, Esq.,
F.R.S., President.

*^ That which can be very easily done, without the exertion
of much skill or ingenuity, is," Mr. Knight observes, *' very
rarely found to be well done, the excitement to excellence
being in such cases necessarily very feeble." This remark
is in the present case applied to the cultivation of celery,
which, being a native of the sides of wet ditches, might
naturally be expected to demand an abundant supply of
water when cultivated. Accordingly, Mr. Knight found that
by keeping the ground, in which celery was planted, con-

Horticultural Society of London, 167

stantly wet, it grew by the middle of September to the
height of five feet, and its quality was in proportion to ita
size. Mr. Knight also recommends planting at greater dis-
tances than is usually the case, and covering the beds, into
which the young seedlings are first removed, with half-rotten
dung, overspread to the depth of about two inches with
mould ; under which circumstances, whenever the plants are
removed, the dung will adhere tenaciously to their roots,
and it will not be necessary to deprive the plants of any part
of their leaves.

VI. Report upon the New or Rare Plants which /lowered in the Garden
..,0/" the Horticultural Society at Chiswick, between March^ 1825, and

^j itarch, 1 S2(j. Part I. Tender Plants, By John Lindley, Esq.

The subject of this paper consisting of botanical details which
do not bear curtailing, we shall only extract the names of
the new species described in it, as a guide to our botanical
readers. In the whole, thirty-three species are noticed;
oi which the following are published for the first time : —

2 Passiflora obscura. 7 Solanum dealbatum. 10 Taber-
naemontana gratissima. 13 Tephrosia ? Chinensis, 15 Hel-
lenia abnormis. 16 Gesneria Douglassii. 21 Gynandropsis
pulchella. 23 Rodriguezia planifolia. 26 Brassavola nodosa.
33 Phycella corusca.

VII. Aocounf of a Protecting Frame for Fruit- Trees on Walls, By

Mr. John Dick.

In order to protect the fruit upon walls from the ravages of
bees, wasps, flies, and other winged enemies, a frame is con*
triVed fitting close to the face of the wall, and having a move-
able sliding canvass front, which can be readily removed when
the fruit is to be gathered, and replaced again afterwards^
A plan of the frame accompanies the paper. From what we
have seen of this contrivance, we know that it is well adapted
to its purpose, and that no garden in which fine fruit is re-
quired, should be without one or more of such frames. For
the mode of making them, we must refer to the paper itself*

VIII, On the Esculent Egg- Plants. By Mr. Andrew Mathews.

In this country, the egg-plant, brinjal, or aubergine, fe
chiefly cultivated as a curiosity ; but in warmer climates,
where its growth is attended with less trouble, it is a fa-
vourite article of the kitchen-garden. In the form of fritters,
or farces, or in soups, it is frequently brought to table in
all the southern parts of Europe ; and forms a pleasant va-

165 . ' Transactions' of the

riety of esculent. This paper describes the only two kinds
that are worth cultivation in England.

IX. Notices of Communications to the Horticultural Society^ between
Januat-y 1, 1824, and January \y^\^!^ cj^^f<'^^/''^^^^ Minute
Books and Papers of the Society. " ; i . , / ; ■ ; . ■ , : ,

A novel kind of pine pit is described, which is said to answer
every purpose that can be desired. It is heated by flues
passing through a chamber, formed by beams extending from
the back to the front wall, and so becoming a sort of floor,
upon which is first placed a layer of turf; and then the tan
in which the pine-plants are plunged. The warmer air is
conveyed into the upper part of the pit by means of small
apertures contrived in the walls, at four inches and a half
apart, both in the back and front of the pit, and also through
iron pipes resting on the beams and passing through the tan.
The ventilation is efl'ected by air-holes in the front wall, and
sliding shutters in the back walls. An explanatory figure
accompanies the statement.

The famous rhubarb, which has of late acquired so much
celebrity under the name of Buck's rhubarb, is mentioned as
excellent when forced. It is not generally known, that this
sort is the genuine Rheum undulatum of botanists unconta-
minated by mixture with the common garden kinds. The
plant generally called Rheum undulatum, is a half-bred, pos-
sessing none of the good qualities of the native species... (i^tyr^'
George Toilet, Esq., of Betley Hall, in Staffordshire, re-
commends the preservation of apples for winter store, packed
in banks or hods of earth like potatoes. The method js said
to be effectual and economical.

Thomas Bond, Esq., of East Looe, in Cornwall, describes
his mode of cultivating strawberries. He does not adopt
the common practice of cutting off" the runners, but they are
confined to the bed by being turned back among the plants
from which they spring. In the autumn, the beds are
covered to the depth of two inches with fresh earth, through
which the strawberry-plants shoot in the spring with great

vigour.^, r,u. c;t hid ^^w^d . i . . • '' 1 ■-

A kind' of wjcKer'basket is described, which is cheap and

well adapted for screening half hardy plants during the

winter. It is fixed in the earth by means of the points of

the ribs of the wicker work, which are allowed to project a

few inches for the purpose. , .

It is stated by John Wedgewood, Esq., that good celery

may be readily obtained by transplanting seedling plants

that have remained in the seed bed, till they had acquired a

Horticultural SociHy of Ldndon. 16^

considerable size. They grow more vigorously than the
younger plants that are transplanted in the usual way.

William Cotton, Esq., of Wellwood-housc, describes the
good fefiTects of painting an old garden wall with seal oil and
anticorrosion paint, The wall in question was covered with
tree^, Which were every year attacked by blight. Since the
optt*ation the trees have borne good fruit, made healthy
woodi and been free from the bad consequences of blight.

Mr. John Mearns states, that the red and white Antwerp
raspberries may be brought to bear abundantly in August,
long after the usual crop of raspberries is past, by the follow-
ing management. In May he removes the young fruit, bear-
ing shoots, from the canes, leaving in some cases one or two
eyes, in others, cutting them clean off. Under either plan,
they soon produce an abundance of vigorous new shoots,
which blossom freely in July.

Mr.Elias Hildyard, gardener to Sir Thomas Frankland, kills
the grub which infests his onion beds by trenching the beds in
winter, digging in manure at the same time, and leaving them
exposed to the frost in a rough state till the time of sowing* '

A mode of inducing fertility in a barren SwanVegg pear-
tree trained upon a wall, is described by the Rev. John
Fisher, of Wavenden, in Buckinghamshire. It consists in
twisting and breaking down the side shoots of the main
branches in such a way, as to make them pendulous without
separating them wholly from the parent limb. In a short
time a grumous formation takes place where the fracture has
occurred, the wound heals, the flow of the sap is moderated,
and fruit buds are formed instead of sterile shoots.

Mr. William Mowbray, gardener to the Earl of Mount-
norris, states, that the different species of eatable Passifloras
which do not generally produce fruit, may be induced to do
so abundantly, if the pollen of other species is applied to
their stigmas.'^ » .>rn,-. n •• a\ ^ .;Kr;-^|. vv.i,' ifcfdvr /:

Currants are preserved in perfection fn tlie garden of Jfames
Webster, Esq., of Westham, by being covered with bunting
when the fruit is fully ripe, care being had to unloose the
bunting occasionally from the bottom Or the bushps, in, bidder
to remove the decaying fallen leave^V':*''^*'^'^, "^""l boJqcDB ^ ^

X. Hepgrt on the Instruments employed in, and on the Plan of a jour-
nal of Meteorological Observations ^ kept in the garden ofJhe Hqrti'
cultural Society at Chistmck^ , ,f, ^'!i i '"'"1 iV'!'' '

This and the following paper we propose' td notice in
(Jetail ou a future occasion.

170 Transactions of the

XI. Joumcd of Meteorological Observations made in the garden of th&
Horticultural Society at Chiswick, during the year 1826. By Mr.
William Beattie Booth. ■

XII. On Orache, its Varieties and CultivatiotL.\m Mr. William

Townshend. ^"' ^'

The herb orache was formerly cultivated as a kind of sum-
mer spinach ; but in this country it has long been expelled
from the kitchen garden by other kinds. It is, however, still
seen in the gardens of France, where it is commonly called
Arroche des jardins, being used in that country, both by
itself as a spinach, and mixed with sorrel, the acidity of which
it corrects. Seven varieties are described, which do not differ
in their qualities, but are distinguished by the colour of their
foliage.

XIII. On planting the moist Alluvial Banks of Rivers with Fruit-Trees,

By Mr. John Robertson.

The object of this writer is to show that the low grounds
that form the banks of rivers are, of all others, the best
adapted for the growth of fruit trees ; the alluvial soil
of which they are composed, being an intermixture of the
richest and most soluble parts of the neighbouring lands,
with a portion of animal and vegetable matter, affording an
inexhaustible fund of nourishment. In such situations, how-
ever, the trees are liable to injury from floods in the winter,
unless some means are used of draining off the stagnant water.
This is to be effected by digging deep trenches between the
rows of trees, casting up the earth from the trenches around
the trees on either side, so as to form elevated banks. Such
is the practice in Holland, where the western slopes of the
dykes are generally covered with fruit-trees, chiefly apples and
pears. Mr. Robertson is of opinion, that the banks should be
raised, if possible, at least three or four feet above the highest
water-mark, and be made eighteen feet broad at the base, and
twelve at top ; the trenches should be fifteen or sixteen feet
wide, admitting the soil to be three or four feet deep.

Upon this plan, it is probable that abundant crops would
be obtained ; but with regard to the quality of the produce,
we suspect it will be quite as indifferent as the apples and
pears of the Dutch, which are notorious for their want of
flavour. ^■''- ^^^^^-"-^-^ -:?''f'>'^ ■' ^rii V'

'^IV.'Onmhlids. % Mr. William Smith. '- '

This is an attempt to distinguish by words the best varieties
of the Dahlia, and to fix the names of those which are the
most worthy of cultivation. Sixty kinds are well described,

Horticultural Society of London, l71

arranged in divisions depending upon the size of the plants
and the colour of their flowers. We do not propose to analyze
this paper, which is far too extensive for our limits; but in-
steaa, to throw together a few remarks which are suggested
by the subject.

The first Ikct to which we would call attention has reference
to Acclimatization. The Dahlia has now been cultivated in
Europe with the utmost assiduity for nearly thirty years. Du-
ring tnat period millions of plants have been raised from seeds,
and under almost every possible variation of climate; and ano-
Irialie^ the niost singular, not only in colour, but in general
Constitution and physiological structure, have been obtained.
The colour of the nower has been altered from pale yellow,
or lilac, to every hue of red, purple, or yellow, to pure
scarlet and to deepest morone, or has even been wholly dis-
charged from the radial florets in the white varieties; the
period of flowering has been accelerated nearly two months ;
the tall rank weed, exceeding the human standard in height,
has been reduced to a trim bush, emulating the paeony in
dwarfishness ; the yellow inconspicuous florets of the disk
have been expelled to make room for the showy deep-coloured
florets of the ray ; what is more remarkable still, the same
yellow inconspicuous florets of the disk have been enlarged,
and stained with rich morone, so as to rival the colours of the
ray without losing their own peculiarity of form ; and finally,
the v/hole foliage and bearing of the plant has been altered
by the substitution of simple leaves for compound ones. But
notwithstanding all this proneness to change, notwithstand-
ing the multitude of varieties which have been thus procured
by seed, not one individual has yet been discovered^ in any
degree whatever ^ more hardy than its ancestors. The earliest
frosts destroyed the Dahlias as certainly in 1826, as they could
have done in 1780.

But, however strong may be the disposition of the Dahlia
to vary from its original structure, it is curious to observe
how strictly it conforms to the laws by which such variations
are controlled by nature. In altered structure all the changes
take place from circumference to centre. The florets of the
ray displace those of the disk, but the latter never attempt
to occupy the ray ; when a change occurs among the florets
of the disk, they merely dilate and assume the colour of the
ray, without changing their position or their peculiar form.
So with the leaves; by a reduction of the lateral leaflet, till
the terminal one only remains, simple foliage is substituted
for that which was compound : but no case has been found in

172 Transactions of the

which the suppression of the terminal leaflet has tJiken place
and the lateral ones have been preserved. In change of colour,
too, there is a circumstance which demands consideration, and
of which no explanation has yet been offered. It is not ge-
nerally known, although long ago noticed by M. De Candolle,
that among flowers, yellows will not produce blues, nor
blues yellows, although both these primitive colours will
sport mto almost every other hue. Thus the hyacinth, the
natural colour of which is blue, will not produce a yellow,
for the dull, half-green flowers called yellow hyacinths, are,
in our judgment, whites approaching green ; the blue crocus
will not vary into yellow, nor the yellow into blue ; and the
ranunculus and the dahlia, the natural colour of both which,
notwithstanding the popular belief to the contrary, with
respect to the dahlia, is, we believe, yellow, although they,
are the most sportive of all the flowers of the gardens, vary-
ing from pink to scarlet, and deepest shades of purple, have
never yet been seen to exhibit any disposition to become blue.
This subject offers a most amusing field for investigation,
and would well repay the attentive consideration of the phi«

XV. On the Cultivation of Camellias in an open Border. By Mr*

Joseph Harrison.

Mr. H . finds that the double red camellia, the double white, and
the double striped, will bear an English winter if planted out
when about two feet high, having been previously stunted in
their growth by repeatedly stopping their leading shoots.
For two winters the young plants are to be protected by a
wooden screen fixed round them, and covered by a hand-glass,
the whole being enveloped in mats ; afterwards they require
no other protection than to be guarded from heavy snow-
storms, and to be assisted by a thick covering of old tan upon
the ground in which they grow, to the distance of two or
three feet from their stems. If this success has been met with
in Yorkshire, what may not be expected in our more southern
counties ! On the 12th of March of the present year, these
camellias were not injured by a frost whic|i did considerable
damage to the common laurel. . ' ^ , , ; .,

XVI. A Method of growing Crops of Melons on open Borders. By Mr.

William Greenshields.

The sorts fitted for this purpose are the black rock, scarlet
rock, green-fleshed, netted and early Cantaloup melons. The
method consists of forming a bed, by half filling a shallow

HorlicuUural Society of London, 173

trench with decayed vegetables, and covering them with the
exhausted linings of cucumber beds. The young plants are
reared for some time under handlights. For full particulars
of this practice, we must refer to the paper itself, which is
clearly written^ and, coining as it does from one of our most
skilf u J g^ixleners, well worthy of attention.

Xn(l,'''Ntftic&t>/Five Varieties of P ears teceiwdfrom Jersey in the year
ft , fi 1 1 : 1 826. By John Lindley, Esq.

We fri|^|;s here de^^^ are of the highest excellence. They

are,' 1. the Marie Louise ; 2. the Duchessed*Angouleme ; o,
the Doyenne gris ; 4. the Do3'enn6 panache ; 5. the Beurr^
d*Aremberg ; and 6. the Gloux morceaux. The second, the
fifth, and the sixth kinds are represented in two very beau-
tiful coloured plates ; and are, perhaps, the most exquisitely-
flavoured of all the varieties of the pear. The Beurre
d*Aremberg and Gloux morceaux are long keepers ; the
others are autumnal kinds. Of the former it is said, *^ the
flesh is whitish, firm, very juicy, dissolves in the mouth, and
is wholly destitute of grittiness ; it is sweet, rich, and so pe-
culiarly high flavoured, that I know no pear that can be com-
pared with it in that respect."

XVllI. Upon the Culture of the Prunus Pseudo-cerasus, or Chinese
Cherry. By Thomas Andrew Knight, Esq.

This species of cherry is expected to become an acquisition
of considerable value, for the purpose of forcing ; and also
as an early fruit, when trained upon an open wall. Mr.
Knight recommends its propagation by cuttings, which root
freely, and that it be abundantly supplied with liquid manure.
From its highly excitable habits, he suspects it to be a native
of a cold climate, probably of Tartary,

p^X» On the Culture of the Pine- Apple. By Mr. James D.alL
:rr\ XX. On forcing Asparagus. By the same. :■!"■■'

Thes^. two papers %ifr<^ communicated by the Cambridge
Horticultural Society, having gained one of the annual silver
medals presented by the London to Provincial Societies.
They contain good practical directions fp|;t\he; cultivation
upon which they treat.

XXl.'Ohtervations wpon forcing Garden Rhubarb. By Mr. William

Stdthard.
This plan is perhaps the best that can be followed, as it is at
once the most certain and the most simple. You sow rhu-
barb seed ou a rich moist border in the beginning of April.

174 Transactions of the

The young plants are Well thinned during the summer ; in
the end of October they are very carefully transplanted into
forcing-pots, five or six in each pot. They are placed in ^
north aspect, to recover the eftect of their removal from the
seed-bed, and in a month they are fit for forcing. We can
safely recommend this method. :

XXII. Account of some remarkable Holly Hedges and Tree^ in Slcotlandl

By Joseph Sabine, Esq.

This is an elaborate account of some extraordinary specimens!
of hollies, and appears to have been vrritten with a view to
induce the more general cultivation in this country of that
very valuable tree. At Tynningham, the residence of the
Earl of Harrington, are hedges extending to no less a dis-
tance than 2952 yards, in some cases thirteen feet broad, and
twenty-five feet high. The age of these hedges is something
more than a century. At the same place are individual trees
of a size quite unknown in these southern districts. One
tree measured five feet three inches in circumference at three
feet from the ground ; the stem is clear of branches to the
height of fourteen feet, and the total height of the tree is
fifty-four feet. The other places at which the hollies are of
unusual size, are Colinton-house, the seat of Sir William
Forbes; Moredun, the seat of David Anderson, Esq.;
Hopetoun-house, the seat of the Earl of Hopetoun, and
Gordon-castle, where are several large groups of holliesj
apparently planted by the hand of Nature.

XXIII. An Account of a Plan of Heating Stoves by means of Hot Water^

employed in the Garden of Anthony Bacon, Esq.

We conceive that a new aera in horticulture will commence
with the publication of this paper. We already possessed
contrivances of a sufficiently good kind for all purposes con-
nected with artificial climate, except the power of com-
manding heat ; for which the two methods hitherto employed
have been either too clumsy or too costly, and in either case
liable to numerous objections. The old mode of introducing
heat into a stove, by means of brick flues, has long been
considered so bad, that every scheme that promised to super^
sede such flues has been hailed with joy ; the uncertainty of
the quantity of heat given out by a brick flue, its continual
liability to explosion, the impossibility of preventing the
escape of smoke from between the joints of the bricks, are
all evils that require a remedy. For this purpose steam was
introduced, and with great advantage in extensive ranges of
.hothouses. But the enormous expense of erecting a steam

Horticultural Soi^ety of London, 175

apparatus, the danger attending its use in the charge of an
unskilful or careless gai-dener, and also the rapid loss of
heat from X\\s pipes upon any neglect of the boiler, have all
contributed to prevent the use of steam becoming very ge-
neral. The plan now described has the great merit of pos-
sessing all the good qualities of steam, without any of its
objectionable accompaniments ; its cost cannot in any con-
siderable degree exceed that of flues, and its effects are so
cerUii^ and durable, that a house so heated may be almost
9ai4 ItO l>e beyond the power of neglect on the part of the
gardener.

Without entering into the details of this plan, for which
we must refer to the paper itself, we shall content ourselves
M'ith explaining its principle. Suppose two iron reservoirs,
A and B, of equal capacity, placed twenty feet apart, and
connected at the top and the bottom by iron pipes, the level
of both reservoirs being the same ; it is obvious that water
poured into one of these reservoirs will flow into the other
through the connecting pipes, and that it will consequently
stand at the same height in both. Let the reservoirs be thus
filled above the level of the uppermost pipe, and heat be
applied to the bottom of one reservoir, A ; the water in this
will presently be forced through the upper pipe into the
reservoir, B, of water not heated ; in proportion as the
healed water flows out of A, through the upper pipe, the
cold water will flow out of B through the lower pipe ; and
by this means a circulation of water heated and water to be
heated will be formed, which will continue as long as the
application of fire to the bottom of one reservoir is continued.
When it is discontinued, the temperature of the two reser-
voirs and of the intermediate pipes will be the same within
three or four degrees. As it is the property of heated water
to part with its heat very slowly, it follows that heat will
continue to be disengaged from the reservoirs and pipes long
after the application of fire has ceased. In fact, when the
two reservoirs are once heated^ the gardener may make up
his fires and retire to i*est, certain that his house is suffi-
ciently provided with heat for the night.

The paper is accompanied with a plan of a vinery warmed
upon this principle.

176

On the Recent Elucidations of early Egyptian History.

SixXCE the commencement of the present century, the researches
of philologists have ascertained that the language of ancient
Egypt, — the language of the hieroglyphical inscriptions engraven
on its ancient temples and monuments, and of the still existing
manuscripts of the same period,-*— differs from the modern
Egyptian or Coptic, only in the mixture in the latter of many
Greek and Arabian and a smaller portion of Latin words, in-
troduced during the successive dominion of the Gl^eks, the
Romans, and the Arabs, and occasionally substituted for the
corresponding native words. The grammatical construction of
the language has remained the same at all periods of its employ-
ment : and it finally ceased to be a spoken language towards
the middle of the seventeenth century, when it was replaced
by the Arabian.

In writing their language, the ancient Egyptians employed
three different kinds of characters. First, figurative ; or repre-
sentations of the objects themselves. Second, symbolic ; or re-
presentations of certain physical or material objects, expressing
metaphorically, or conventionally, certain ideas ; such as, a people
obedient to their king, figured, metaphorically, by a bee ; the uni-
verse, conventionally, by a beetle. Third, phonetic^ or represen-
tative of sounds; that is to say, strictly alphabetical characters.
The phonetic signs were also portraits of physical and mate-
rial objects ; and each stood for the initial sound of the word in
the Egyptian language which expressed the object pourtrayed-:
thus a lion was the sound L, because a lion was called Labo ;
and a hand a T, because a hand was called Tot. The form
in which these objects were presented, when employed as
phonetic characters, was conventional, and definite ta distin-
guish them from the same objects used either figuratively
or symbolically ; thus, the conventional form of the pho-
netic T was the hand open and outstretched; in any other
form the hand would either be a figurative, or a symbohc sign.
The number of distinct characters employed as phonetic signs
appears to have been about 120; consequently many were
homophones, or having the same signification. The three kinds
of characters were used indiscriminately in the same writing,

Elucidation of early Egyptian History, 1 77

tind occasionally in tlie composition of the same word. The
formal Egyptian writing, therefore, such as we *See it still
existing on the monuments of the country, was a series of por-
traits - oF physicp.1 and material objects, of which « a small
•proportion had a symbolic meaning, a still smaller proportion
a figurative meaning, but the great body were phonetic or
alphabetical signs : and to these portraits, sculptured or painted
with sufficient iidelity to leave no doubt of the object repre-
sented, the name of hieroglyphics, or sacred characters, has
been attached from their earliest historic notice.

The manuscripts of the same ancient period make us ac-
quainted with two other forms of writing practised by the an-
cient Egyptians, both apparently distinct from the hieroglyphic,
but which, on careful examination, are found to be its immediate
derivatives; every hieroglyphic having its corresponding sign in
the hieratic, or writing of the priests, in which the funeral
rituals, forming a large portion of the manuscripts, are princi-
pally composed ; and in the demotic, called also the enchorial,
which was employed for all more ordinary and popular usages.
The characters of the hieratic are for the most part obvious
running imitations, or abridgments of the corresponding hiero-
glyphics ; but in the demotic, which is still further removed
from the original type, the derivation is less frequently and
less obviously traceable. In the hieratic, fewer figurative or
symbolic signs are employed than in the hieroglyphic ; their
absence being supplied by means of the phonetic or alpha-
betical characters, the words being spelt instead of figured ;
and this is still more the case in the demotic, which is, in con-
sequence, almost entirely alphabetical.

After the conversion of the Egyptians to Christianity, the
ancient mode of writing their language fell into disuse ; and
an alphabet was adopted in substitution, consisting of the
twenty-five Greek letters, with six additional signs expressing
articulations and aspirations unknown to the Greeks, the cha-
racters for which were retained from the demotic. This
is the Coptic alphabet, in which the Egyptian appears as a
written language in the Coptic books and manuscripts pre-
served in our libraries ; and in which, consequently, the lan-
guage of the inscriptions on the monuments may be studied, •
JULY — OCT. 1827. N

178 On the Elucidation of

The original mode in which the language was written having
thus fallen into disuse, it happened, at length, that the signification
of the characters, and even the nature of the system of writ-
ing which they formed, became entirely lost ; such notices
on the subject as existed in the early historians being either
too imperfect, or appearing too vague, to furnish a clue,
although frequently and carefully studied for the purpose;
The repossession of this knowledge will form, in literary history,
one of the most remarkable distinctions, if not the principal, of
the age in which we live. It is due primarily to the discovery
by the French, during their possession of Egypt, of the since
well-known monument called the Rosetta Stone, which, on
Iheir defeat and expulsion by the British troops, remained in
the hands of the victors, was conveyed to England, and depo-
sited in the British Museum. On this monument the same
inscription is repeated in the Greek and in the Egyptian lan-
guage, being written in the latter both in hieroglyphics and in
the demotic or enchorial character. The words Ptolemy and
Cleopatra, written in hieroglyphics, and recognized by means of
the corresponding Greek of the Rosetta inscription, and by a
Greek inscription on the base of an obelisk at Philse, gave the
phonetic characters of the letters which form those words:
by their means the names were discovered, in hieroglyphic
writing, on other monuments of all the Grecian kings and
Grecian queens of Egypt, and of fourteen of the Roman empe-
rors ending with Commodus ; and by the comparison of
these names one with another, the value of all tJie- phonetic
-characters was finally ascertained. i«wi k;JaiiiEd3 sbfvt

The hieroglyphic alphabet thus made out has been subse-
quently applied to the elucidation of the earlier periods of
Egyptian history, particularly in tracing the reigns and the
. succession of the Pharaohs, those native princes who governed
Egypt at the period of its splendour ; when its monarchy was
the most powerful among the nations of the earth; its people
the most advanced in learning, and in the cultivation of the
firts and sciences ; and which has left, as its memorials, con-
structions more nearly approaching to imperishable, than any
other of the works of man, which have been the wonder of
eyery succeeding people, and which are now serving to re-
estabh5h,-at the expiration of above 3000 years, the details of

earhj Egyptian History , ^179

its long-forgotten history* To trace these stupendous monu-
ments of art to their respective founders, and thus to fix,
approximatively, at least, the epoch of their first existence, is
B consequence of the restoration of the knowledge of the
alphabet and the language of the inscriptions engraven on
them. • We proj)Ose to review, briefly as our limits require,
the principal and most important facts that have thus re-
cently been made known in regard to those early times ; and
ahall deem ourselves most fortunate if we can impart to our
readers but a small portion of the interest which we have our-
selves derived in watching their progressive discovery.

The following are the authors to whom we are chiefly in-
debted for the few particulars we know of early Egyptian his-
tory, Herodotus and Diodorus Siculus, Grecians, and foreign-
-ers in Egypt. Manetho, a native ; and Eratosthenes, by birth a
•Cyrenean, a province bordering on Egypt, both residents.
Josephus, a Jew, and Africanus, Eusebius, and Syncellus,
Christians, Greek authors. Herodotus visited Egypt four
centuries and a half before Christ, and within a century after
its conquest by the Persians. In his relation of the affairs of
the Greeks and Persians, he has introduced incidentally a
sketch of the early history of Egypt, such as he learnt it from
popular tradition, and from information obtained from the
•priests. It is, however, merely a sketch, particularly of the
earlier times ; and is further recorded by Josephus to have
•been censured by Manetho for its incorrectness. Diodorus is
also understood to have visited Egypt about half a century
before Christ ; and from him we have a similar sketch to that
of Herodotus ; a record of the names of the most distinguished
kings, and for what they were distinguished ; but with inter-
vals, of many generations and of uncertain duration, passed
without notice. Manetho was a priest of Heliopolis in Lower
Egypt, a city of the first rank amongst the sacred cities of
ancient Egypt, and long the resort of foreigners as the seat of
learning and knowledge. He lived in the reign of Ptolemy
Philadelphus, two centuries and a half before Christ, and wrofe,
hy order of that prince, the history of his own country in the
Greek language, translating it, as he states himself, outx)f the
jsacred records. His work is, most unfortunately, lost ; but
the fragments which have been presen ed to us, by the writings

N2

1.80 .' On the Elucidation of

-of Josephus in the first century of the Christian sera, and by
the Greek authors above named of the third and fourth cen-
turies, contain matter, which, if entitled to confidence, is of the
highest historical value, viz., a chronological list of the succes-
sive rulers, of Egypt, from the first foundation of monarchy, to
Alexander of Macedon, who succeeded the Persians. . This
list is divided into thirty dynasties, not all of separate famihes ;
a memorable reign appearing in some instances to commence
a new dynasty, although happening in the regular succession.
It originally contained the length of reign as well as the name
of every king ; but in consequence of successive transcriptions,
"variations have crept in, and some few omissions also occur in
Ihe record, as it has reached us through the medium of different
authors. The chronology of Manetho, adopted with confi-
dence by some, and rejected with equal confidence by others, —
his name and his information not being even noticed by some
of the modern systematic writers on Egyptian history, — has
received the most unquestionable and decisive testimony of its
general fidelity by the interpretation of the hieroglyphic inscrip-
tions on the existing monuments : so much so, that by the
accordance of the facts attested by these monuments with the
record of the historian, we have reason to expect the entire
restoration of the annals of the Egyptian monarchy antece-
dent to the Persian conquest, and which, indeed, is already
accomplished in part.

Before we pursue this part of our subject, we must conclude
our brief review of the original authorities in early Egyptian
history, by a notice of Eratosthenes. He was keeper of the
Alexandrian library in the reign of Ptolemy Evergetes, the
successor to Ptolemy Philadelphus, under whose reign Manetho
wrote. Amongst the few fragments of his works, which have
reached us transmitted through the Greek historians, is a cata-
logue of thirty-eight kings of Thebes, commencing with Menes,
(who is mentioned by the other authorities also as the first
monarch of Egypt,) and occupying by their successive reigns
1055 years. These names are stated to have been compiled
from original records existing at Thebes, which city Eratos-
thenes visited expressly to consult them. The names of the
two first kings in his catalogue are the same with the names
of the two first kings of the first dynasty of Manetho ; but the

early Eyyptian History, 181

remainder of the catalogue presents no further accordance,
either in the names or in the duration of the reigns.

To return to Manetho : — amongst the monarchs of the ori-
ginal Egyptian race there was one named by him Amenophis,
(the eighth king of the eighteenth dynasty,) of whom it is
stated, in a note of Manetho' s preserved by Syncellus, that he
wa^'the Egyptian king whom the Greeks called Memnon.
The statue of Memnon at Thebes, celebrated through all anti-
quity for the melodious sounds which it was said to render at
sutirise, is identified in the present day by a multitude of Greek
inscriptions ; one of which, in particular, records the attestation
of Publius Balbinus, who visited the ruins of Thebes in tha
suite of the empress the wife of Adrian, to his having himself
heard the " divine sounds of Memnon or Phamenoph ;" which
latter name is Amenophis, with the Egyptian masculine article
<p prefixed, and omitting the Greek termination. The hiero-
glyphics carved on the statue, and coeval with its date, had
been very carefully copied by the French whilst in possession
of 'Egypt^* and were engraved in the splendid work, the
Description de VEgypte, to which their researches had given
rise. These hieroglyphics contain the alphabetic characters
Amnf (being the initial vowel and all the consonants of the
name Amenof ) inclosed within a ring ; a distinction which had
been previously observed to take place with the names of the
Roman emperors, and of the Grecian kings and tjueens ; and
as the rings have hitherto been found to occur in no other
instance whatsoever than when containing the names and tides
of sovereigns, they are regarded as characteristic signs. It
should be remarked, that in the hieroglyphic writing, as in the
languages of other eastern nations most nearly connected with
Egypt; the vowels are often omitted, and when expressed, have
not always a fixed sound. The coincidence of the reading of
the hieroglyphic name with that recorded by Manetho, and with
the Greek inscription on the statue itself, was so far confirma-
tory of Manetho's authority ; it was also highly interesting in the
evidence it afibrded of the employment of the same hierogly-
phic alphabet, that was in after use in the times of the Ptole-
mies and the Ca?sars, even in the very early periods of the
Egyptian monarchy ; for the reign of Amenophis was in the
dynasty preceding that of Sesostris; it also indicated the further

182^ On the Elucidation of

advantage to be gained by the application of the alphabet in
decyphering other proper names, distinguished by being in-
closed in rings, existing on other statues, and in the more
ancient temples generally. Considerable progress had been
made in reading these, which in several instances had been
found to correspond with the names of the kings of the same
and of subsequent dynasties to Amenophis, as given by Ma-
netho, when a most important discovery was made of the exist-
ence of a genealogical record, in hieroglyphics, of the titles of
thirty-nine kings anterior to Sesostris, chronologically arranged.
We have already noticed that the names and titles of kings
were distinguished by being inclosed in rings ; the ring con-
taining the proper name being accompanied usually by a se-
cond, inclosing certain other hieroglyphics, expressing the title
by which that particular king was designated ; and it appears
probable that the kings of Egypt were distinguished by their
titles rather than by their names, since the same name recurs
frequently in different individuals, but the titles are all dissi-
milar ; with a single exception amongst the very many that
have come under observation, and in which the same title is
common to two brothers. The signification of the titles is yet
obscure, except that they are of the same general nature as is
frequent in the East, such as '^Sun of the Universe," &c. ; but
for the purpose of individualizing, the sign is to us of the same
value as the thing signified ; and as other monuments furnish
the names in connexion with the titles, we are enabled to com-
pare the succession evidenced by the titles with the record of
the historian, and thus to test the fidelity of the record. The
discovery of this hieroglyphic table was made by Mr. Wil-
liam Banks in 1818, in excavating for the purpose of obtain-
ing an accurate ground-plan of the ruins of Abydus, near
Thebes. On a side wall of one of the innermost apartments,
hieroglyphics were sculptured inclosed in rings, ranged symme-
trically in three horizontal rows, each row having originally
contained twenty rings, of which twelve of the upper row,
eighteen of the middle, and fourteen of the lower row were still
remaining, the others having been destroyed by the breaking
down of the wall. The hieroglyphics having been copied and
lithographed, it was speedily recognised that the rings in the two
upper rows consisted of titles only j with the exception of one

early Egyptian History* 183[

proper name, the last of the second row, since knowti to be the
name of the king whose title is the last in the succession, and
who was the fourth in reign and generation before Sesostris.
The third row was recognised to consist of one proper name
and one title, each repeated ten times, and alternating with
each other : these are since known to be the name and title of
Sesostris, to whose reign the construction of the table is with
much probability ascribed. The titles in the same row \Vith
that of the ancestor of Sesostris and preceding it, have been
identified on other monuments, coupled with names which are
those of the predecessors of the same king in the list of Manetho.

It would exceed our limits, and it is not our purpose, to
trace in detail the successive steps by which the existence of
each of the kings of Manetho's list, from the expulsion of the
Phoenician shepherds from Lower Egypt, and the consequent
union, of Upper and Lower Egypt in a single monarchy, to
the reign of Sesostris, has been attested by the monuments.
Suffice it to say, that the same number of individuals as
stated by Manetho, namely, eighteen, filling a space of four
centuries, are shown, by the monuments, to have reigned in
that interval, and to have borne the same relationship, as well
as succession, to each other, as is expressed by the historian :
that, of the eighteen names, eight in different parts of the list
are read on the monuments identically as in the historical
record ; and that in regard to the names that are not identical,
we have the testimony of Manetho that some amongst the
kings, Sesostris, for example, were known by two and even by
more names. The table of Abydus appears to have been
strictly a genealogical record ; a record of generations, in which
■view it is strictly accordant with the historian.

The period of the Egyptian annals on which this light has
b^en thrown, is precisely that which might have been selected
in the whole history of Egypt as the most desirable for such
purpose. Independently of its very high antiquity, it was the
period of the greatest splendour and power of the native Egyp-
tian monarchy, and of the highest (Egyptian) cultivation of
the arts. The greater part of the more ancient, and by far the
most admirable in execution, of the temples, palaces, and sta-
tues, which still attest by their ruins their former magnificence,
are the work of that age ; and the hieroglyphic inscriptions stiU

184 • On the Elucidation of

extant on them, and which, when not defaced by wanton injury,
are almost as perfect as when first executed, make known the
reigns in which they were respectively constructed, and fre-
quently the purposes for which they were designed. This is in
itself no small achievement, when we reflect that these extraor^
dinary remains of ancient art were equally the objects of vague
wonderment in the times of the Roman emperors, as they were
in those of the generation preceding ourselves; but that they are
become to us objects of a more enlightened curiosity, which they
promise amply to repay, when the study that has already made
known their founders, shall reveal the signification of the hie-
roglyphic histories, with which the walls of the palaces and
temples are covered. Already have we gained some very im-
portant facts in regard to the condition, political and other-
wise, of the countries adjoining to Egypt at that early period.
The monuments of Nubia are covered with hieroglyphics, per-
fectly similar both in form and disposition to those on the
edifices at Thebes ; the same elements, the same formulae, the
same language ; and the names of the kings who elevated the
most ancient amongst them, are those of the princes who con-
structed the most ancient parts of the palace of Karnac at
Thebes. As far as Soleb on the Nile, 100 leagues to the
south of Philse the extreme frontier of Egypt, are found con-
structions bearing the inscriptions of an Egyptian king ; evi-
dencing that, during the period of which we have been treating,
Nubia was inhabited by a people having the same language,
the same belief, and the same kings as Egypt. To the south
of Soleb, and for more than 100 leagues in ascending the Nile^
in ancient Ethiopia, very recent travellers have discovered
the remains of temples, of the same general style of architec-
ture as tlK)se of Nubia and Egypt, decorated in the same
manner with hieroglyphics representing the same mythology,
and analogous to those of Egypt in the titles, and in the
mode of representing the names and titles, of the sovereigns.
But the proper names of the kings inscribed on the edifices
of Ethiopia in phonetic characters, have nothing in common
with the proper names of the Egyptian kings in the dynasties
of Manetho ; nor is one of the Ethiopian names found either
on the monuments of Nubia or of Egypt. Thus there was a
time when the civilized part of Ethiopia,— Meroe, and the banks

carhj Ef/yptian History, 185

of the Nile between Dongola and Meroe, — were inhabited by a
people having language, writing, religion, and arts similar to
Egypt ; but, in political dominion, independent of that country,
and ruled by kings of whom it does not appear that any his-
torical record whatsoever has come down to us.

The dates of the expulsion of the Phoenican shepherds from
Egypt, and of the reign of Sesostris, in years of the aera of
our computation, have been favourite subjects of discussion
with chronologists : Archbishop Usher fixed the former of
these events in the year B. C. 1825 ; which would make the
commencement of the reign of Sesostris about B. C. 1483.
The reign of Sesostris is connected with the early Grecian
chronology by the migration of Danaus, brother of Sesostris,
who, according to the Parian marbles, arrived in Greece in
1485, which is a very few years earlier than the dates of Usher
would assign to that event. M. ChampoUion Figeac, brother
of the M. ChampoUion to whom the greater part of the disco-
veries made by the interpretation of hieroglyphics are owing,
himself a distinguished chronologist, has assigned the year B.C.
1822 to the expulsion of the Phoenicians, which Usher had
placed in 1825 : the date of M. ChampoUion being derived
from Manetho's statement, that the Phoenician invasion took
place in the 700th year of the Sothiacal period, viz.^ B.C. 2082,
and that their dominion in Egypt continued 260 years. His-
torical accuracy may make it desirable, that the exact year of
the most ancient as well as of more modern events should
be determined, if it be possible : but for purposes of general
interest, and especially for comparison with the chronology of
cotemporary nations, which at that early period is in every case
more unsettled than the Egyptian, the period seems sufficiently
determined. The date before Christ 1822^ pursued downwards
through the dynasties of Manetho, conducts with very close
approximation to the known period B.C. 525 of the conquest
of Egypt by the Persians ; and intermediately, accords very
satisfactorily with the dates, according to the Bible chronology,
of the conquest of Jenisalem in the reign of Jeroboam by
Shishak, king of Egypt, and of Tirhakah, king of Ethiopia and
Egypt, who made war against Sennacherib ; these are the
Sesonchis of Manetho, and Sh.sh.n.k of hieroglyphic inscrip-
tions on a temple at Bubaste, ajid on one of the courts of the

186 . On (he Elucidation of

palace at Karnac, — and the Taracus of Manetho, and T.h.r.k
of hieroglyphic inscriptions existing in Ethiopia and in Egypt*,
.In respect to the connexion of the events of the Jewish and
Egyptian histories, the period between the expulsion of the
Phoenicians and the reign of Sesostris possesses a peculiar in-^
terest, as being that of the residence of the Israelites in Egypt,
and of the Exodus. In the history of Josephus^ we have an
extract from Manetho, in which this latter event is expressly
stated to have taken place under the father of Sesostris, a king
whose nam6, in Manetho' s list, is Amenophis, (the third of that
name,) and on the monuments Ramses. The date which chro-
nologists are generally agreed in assigning to the Exodus is
1491 ; that of the termination of the reign of Amenophis, ac-
cording to Champollion, is 1473, or, if the correction of his
chronology which we have suggested in a note be just, 1478 :
it is singular that the difference of thirteen years (between 1491
and 1478) should be precisely the duration of a very suspicious
interval which Manetho states to have taken place, after Ame-
nophis had gone with his army in pursuit of the Israelites; and
during which interval neither the king nor his army returned to

* It appears to us that a flight inaccuracy has crept into the deduc-
tion of all the dates in M. Champollion's Chronology subsequent to the
expulsion of the shepherds. The date of that event is the foundation of
the subsequent dates, and is supposed to have taken place B.C. 1822;
after which, according to the extract of Manetho in Josephus cited by
M. Champollion, Thoutmosis, the king by whom they had been expelled,
reigned 25 years and 4 months, followed by the other kings of the
eighteenth dynasty, making altogether 342 years and 9 months : (in-
bluding the 2 years and 2 months additional of Horus, in compliance
with the version of the passage in the Armenian text of the Chronicle of
Eusebius.) This number, 342 years and 9 months, falling short of
the 348 years attributed to the eighteenth dynasty in Eusebius and
Syncellus, M. ChampoUion has suggested that Thoutmosis may have
reigned the five years which constitute the difference, before the ex-
pulsion of the shepherds, since, according to the record, he did reign,
some years before that event, over all "the parts of Egypt not pos-
sessed by the shepherds. So far, so well : but in such case, the year
B.C. 1822, being the epoch of the expulsion of the shepherds, arid not of
the commencement of the eighteenth dynasty, must surely correspond to
the fifth year of the reign of Thoutmosis, and not to the first, as M.
Champollion makes it. We have hesitated to venture this remark on a
matter to which M. Champollion mu,st have given so much attention,
believing that mistake in us is much more probable than an accidental
inadvertence in him ; but we have returned frequently to the consider-
ation, without having been able to satisfy ourselves ; and the rectifica-
tiou of our mistake, if it is one, may prevent others falling intp the same.

early Egyptian History, 187

Egypt, but are stated to have been absent in Ethiopia. If the
Exodus occurred during the reign of any of the kings of the
eighteenth dynasty, it could only have been in the reign of the
immediate predecessor of Sesostris j since his conquests in
Phoenicia, and his expeditions against the Assyrians and Medes,
must have brought him in contact with the Israehtes, had they
been then residing in the Holy Land, so as at least to have
caused some mention to have been made in their history of the
passages of so great a conqueror. But presuming Amenophis,
father and predecessor of Sesostris, to have been the Pharaoh of
the Exodus, the wandering of the Israelites in the desert for
forty of the fifty-five years ascribed to the reign of Sesostrisi, is a
sufficient explanation of his being unnoticed in the Jewish his-
tory ; whilst the fact of that nation having been subject to the
Egyptians during the reign of Ousirei^ commencing 124 years
before the death of Amenophis, is attested by the paintings on
the wall of one of the chambers of the tomb of that king, dis-*
covered by Belzoni, and with which we are so well acquainted
by means of the model exhibited in England.

Whilst recalling to recollection the peculiar physiognomy of
the Jews pourtrayed in that tomb, — and which is as character-
istic of their present physiognomy as if it had been painted in
the present age, instead of above 3000 years ago, — the equally
well characterized, but very different physiognomy of the Phce-.
nician shepherds, represented on the monuments of the same
period, is decisive of the error of Josephus, who imagined the
Jews and the Shepherds to be the same people. The Phoeni-,
cian shepherds, long the inveterate enemy of the Egyptians, form
a leading feature as captives, in the representations of the ex-
ploits of the monarchs who conducted the warfare against them.
These people are always painted with blue eyes and light hair ;
and it is not a little curious to see assembled on the wall of the
same apartment, different races, so distinctly characterised as
the Jew, the Phoenician, the Egyptian, and the Negro ; the
latter in colour, and in the outline of the features, in painting
and in sculpture, precisely as at present; all, moreover, inhabi-
tants of countries not very distant from each other, and at a
period when not more than twelve or thirteen centuries had
passed since all these races had descended from a single parent.
In the writings which attempt to explain from p?^tural causes

IBJ On the Elucidation of

the diversity of race amongst mankind, much power has been
ascribed to the effects of time and climate : but the facts with
which we are now becoming better acquainted than before, do
not appear to admit of explanation from those circumstances.
It is worthy of notice that the negro, and the light-haired and
blue-eyed people, the two races who might be deemed at the
greatest distance apart amongst the varieties of man, at-e, equally
with the intermediate Egyptians, the descendants of Ham.

Of the succession of kings in Manetho's chronology, from
Sesostris to the Persian conquest, a space of nine centuries and
a half, about one half the names have been already identified
on different monuments: four of the Persian monarchs, subse-
quent to the conquest, have also been traced in inscriptions in
phonetic characters ; their names are ^vritten, as nearly as can
be spelt with our letters, Kamboth, (Cambyses) ; Ntariousch,
(Darius) ; Khschearscha, (Xerxes) ; and Artakschessch, (Ar-
taxerxes.)

The ascent by monumental evidence to yet more remote an-
tiquity than the expulsion of the Phoenician shepherds, (B.C.
1822), is not altogether without hope, notwithstanding the
general demolition of the temples of the gods, which took
place according to Manetho, during the long dominion of the
Phoenicians in Egypt. We learn from the Description de
VEgypte that even the most ancient structures at Thebes are
themselves composed of the debris of still more ancient build-
ings, used as simple materials, on which previously sculptured
and painted hieroglyphics are still existing ; these are doubtless
the remains of the demolished temples, but the inscriptions will
require to be studied on the spot. There is also reason to be-
lieve, that there exists amongst the ruins of the palace of Karnac,
a portion of still more ancient construction than the palace itself;
which, having escaped demolition, was incorporated with the
more recent building. The inscriptions on this apparently very
ancient ruin present the name and title of a king, which form a
very interesting subject for future elucidation. The title does
not accord with any one now extant on the table of Abydus, but
possibly may have been one of those which were destroyed with
a portion of the wall, and which are of kings of earlier date than
the expulsion of the shepherds. The name is Mandouei, which
name occurs in the dynasty anterior to Sesostris^ but coupled

early Egyptian History, 189

with a different title, an effectual distinction ; nor does the
name recur in any subsequent dynasty. M. Champollion
Figeac has, with mucli ingenuity, shown the probability of the
identity of the Mandouei of the ancient ruin with the Osyman-
dyas, Ousi-Mandouei, mentioned by Diodorus Siculus as an
Egyptian king greatly distinguished by his conquests, whose
reign M. Champollion infers, from the historical passages re-
lating to him, to have commenced 190 years before the Phoe-
nician invasion, or B.C. 2272 years ; a prodigious antiquity,
and of the very highest interest should it be established, since
there exist of this individual no less than three statues in
European collections, distinguished by the same name and
title : two of these are colossal, one at Turin, and a second at
Rome : a third is in the British Museum ; and as all particu-
lars must interest which relate to a statue, of which there is
at least probability that it is the most ancient existing in the
world, — the date attributed to it being earlier than the birth of
Abraham, — ^we copy from Burckhardt the following short de-
scription of its discovery: " Within the inclosure of the inte-
rior part of the temple at Karnac, Belzoni found a statue of a
hard, large-grained sandstone : a whole length naked figure
sitting upon a chair with a ram's head upon the knees : the
face and body entire ; with plaited hair falling down to the
shoulders. This is one of the first, I should say, the first
Egyptian statue I have seen : the expression of the face is ex-
quisite, and I believe it to be a portrait." — (J. L. Burckhardt,
IVavels in Nubia^ Ixxvii. Letter to Mr* W, Hamilton^ 20th
February f 1817.) — This statue is in the farthest corner on the
right hand side after entering the gallery of the Egyptian anti-
quities in the British Museum; and compared with other
statues in the same gallery, which are of kings of the eighteenth
dynasty, the dissimilarity of the features from the very charac-
teristic ones of the latter family is too striking to be questioned.
The problem of the age of this king Mandouei is, at all events,
a highly curious one ; and will probably receive its solution
amongst the many other valuable discoveries which cannot fail
to result from M. ChampoUion's projected visit to Egypt, in
which he will be accompanied by the sincere good wishes of
every one in every country, who feels an interest in tlie restora-
tion of authentic history. E. S,

mi 190

Proceedings of the HorticuUural Seciefy,

At this meeting a paper ir as read from the President, T. Aw Knight,
Esq., upon the culture of the mango and cherimoyer. Its object
was to suggest some improvements in the management of these
and other trees cultivated in stoves, deduced from an application
of JDutrochet's electrical theory of vegetation to practice. It has
tiow become generally known that this observer is of opinion that
the motion of the fluids in plants depends upon two currents of
electricity, setting with very unequal force between the denser fluid
of the tree and the lighter fluid of the soil in which the tree is
planted; the more powerful current setting from the latter to the
former, and so producing absorption, by conveying aqueous par-
ticles into the roots, through the vegetable membrane of the epi-
dermis. In applying this theory to practical purposes, Mr. Knight
recommends that the pot in which the cherimoyer or mango is
planted, should itself be surrounded by a medium through which
an equable and regular supply of fluid may be conveyed to the
foots, and tliat the naked surface of the pot should by no means be
exposed to the free action pf the atmosphere. Without entering
upon any question of the accuracy of the French philosopher's
observations, it is quite certain that such a mode of cultivation is
that which is most congenial to plants, and which is indispensable
to thos6 of a habit at all delicate. The common practice of
plunging pots into a tan-bed, or among sand, if in glass-houses,
or in the earth if in open borders, is a proof of the necessity that
gardeners have found, of securing as regular a temperature and
degree of humidity as is possible for the outside of their flower-
pots ; through the pores in which, moisture is chiefly conveyed to the
roots, which always cling to the inside surface of the pot.

Specimens of roses produced by branches budded upon the Rosa
indica, were exhibited by Alexander Evelyn, Esq. We notice these
not only on account of their extraordinary beauty, but also for the
sake of recommending most strongly the adoption of the practice
where delicate roses are found difficult of cultivation j9er se. If we
consider what happens when the operation of budding, or grafting
has succeeded, the reason of the advantage derived from such an
operation will be apparent. When a bud of one variety is inserted
under the bark of another variety, a union takes place between the
cellular substance of tlie two ; the bud is then placed in the same

Proceedings oflhe Horticultural Society^ 191

feituation with regard to the stock, as the seed when sown is with
regard to the earth. It immediately derives its nutriment from the
ascending sap of the new tree, and begins to form its wood and
branches, and to secrete its proper juices in proportion to the sup-
ply of food it now receives. If a plant from any cause produces
roots with difficulty, its whole habit will be delicate, and its flowers
if formed, will, as in the case of that most lovely of flowers, the
double yellow rose, probably fall off without expanding, from the
want of an adequate supply of nutriment from its roots ; but, as in all
trees, every bud is, when fully formed, in itself a perfect and distinct
individual, if such an individual be removed from its own root, and
placed where it will be supported by the healthy vigorous roots of
another species of variety, which happens in budding, it will no
longer have to depend upon a source, the supplies from which are
imperfect, but on the contrary, like a seed removed frorti barren to
fertile ground, it will flourish in a degree before unknown. The
contrary effect takes place when a vigorous plant is transferred to
t)ne less vigorous. And hence, the whole effect of stocks upon the
scions, or buds inserted upon them. '

Therfe was also a great variety of fruit and flowers upon the table,
and seeds of several useful vegetables were distributed.

-^^^^ July Srd.

Seven medals were awarded to different individuals for fruit sent
■\)y them to the Society's f^te on the 23rd of June ; and one to
Capt. Drummond, for his ** successful exertions in bringing living
plants of the mangosteen from the East Indies." A paper by the
president was read upon an improvement in the mode of construct-
ing hotbeds, but we despair of explaining it successfully without
Teference to figures. Among the display of fruits and flowers,
which were exceedingly numerous, we were particularly struck by
a collection of Iwenty-two varieties of strawberries from the Society's
garden.

iufpon this occasion, thirty-nine new members were either bal-
lotted for, or proposed, a striking proof of the estimation in which
the Society is held by the public.

July nth.
Upon this occasion, an enormous pine-cone from the River Co-
lumbia was exhibited. It measured 16j inches in length, and was
stated to have been procured by the Society's collector, Mr. David
Douglas. ' Its seeds were represented to be as large as those of the
stone-pine, and eatable.^ The tree is of the family of Pinus strobus,

192 Proceedings of the HortlcuUural Society .

and will be an invaluable acquisition to our forests, if it should
prove to succeed as well in this climate as in its own. We have
already given some account of this plant in the last number of the
old series of this Journal, The usual display was made of the finest
fruit and flowers of the season.

August 7th,

A complete coloured set of the costly Flora danica was placed
upon the table, having been presented by His Majesty the King of
Denmark. An improved apparatus for fumigating hothouses was
exhibited by its inventor, Mr. John Read: it consists of a brass
cylinder, attached to the orifice of a pair of bellows, and fitted up
with a chimney and draft-hole closed by a valve. The tobacco is put
into the cylinder and ignited, and the blast from the bellows expels
the smoke. The contrivance is ingenious enough, but while a hot-
house fifty feet long, may be filled with smoke in ten minutes by
means of a flower-pot, with a hole in its bottom, and a common
pair of bellows, we cannot recommend any more expensive, and
certainly less efficient apparatus.

The table was covered with a profusion of fruits and flowers.

August 2lst,
The meeting-room this day exhibited a gratifying proof of the
excellence of the productions of our English gardens. O^ flowers,
there were dahlias of the richest colours, and the most varied hues ;
some produced by plants that retain all their ancient stature, and
others by dwarfs which seem to have lost nearly every character of
the dahlia but its beauty. Of fruits, there were endless varieties
of apricots, apples, pears, peaches, nectarines, grapes, pine-apples,
and melons ; one of the latter, from the garden of John Fuller, Esq.,
weighed thirteen pounds. The best apricot was the Moorpark ; the
best apple, the Duchess of Oldenburg, than which no princess has a
fairer bloom, the best pear the Jargonelle, the best peach the Bour-
dine (forced), the best pine apple the Black Jamaica. We mention
these as a guide to our readers, in their purchases of fruit-trees ;
for it is certain, that no greater service can be rendered to the public,
than to point out the means by which they may avoid encumbering
themselves with the polyonymous trash with which every nursery
abounds.

ioiii 10 ,{< -

^193

M>B

MISCELLANEOiJS lOTKLLiGENCE.

If (>

ECHANICAL SciENCE.

1. On the combined Action of a Current of Art Cthd'ihe Pressure,
of the Atmosphere. — The pl^uiomena observed by M. Clement
Desormes*, when a flat plate is opposed to air or vapour passing
into the attnosphei'e from an aperture in a plane sttrface, liave been
rendered so easy of pi-ddviction by M. Hachette, as to be at the
command of any person in any situation. M. Hachette has also
^ccQi^i panic d the description of, his instruments jiyith elucidations,
experiments, and philpsophical reasonings. , - ,

Tlie first simplification by M, Hachette was to make the nozzle
of a pair of double chamber-bellows terminate in the middle of a
flat plate ; lie found that when the bellows were worked, effects were
produced opposite the jet of air of the kind described by M.
Cieonent, disks of card and other substances being; drawn towards
the ^erture against the direction of the current. At the same
time that lie described this experiment, he also announced his hav-
ing produced the same effects by using a stream of water instead
of a stream of air.

The apparatus was still further simplified, so as to make the
stream of air from the mouth sufliciqnt to produce the effect. A

i>»'{|3fcl

hiM\\Q0U. «<tr iRv

tin tube, A, Fig, 1, was soldered tothetniddle of a round tin plate,
in the centre of which was a small orifice, E ; three or four small
projections of the tin, // were left at the edges of the plate, to pre-
vent the disks of paper, card, or metal, fi-om slipping o(f sideways.
The figure is on a scale of one-half. Instead of the tin plate, a piece

* See the last volume of Jhis Journal, p. 47S.
JULY— OCT, 1827.

194 Miscellaneous Intelligence.

of smooth cork may be used, and for the tin tube, a glass tube, or
one made by rolling up a piece of paper.

If the tube be held horizontally, or inclining a little upward,
and a disk of card o.r paper be placed loosely against the aperture
in the plate, it will be found that, on applying the mouth to the
end of the tube, and blowing air through, that the disk will not be
driven away, but actually made to apply closely to the surface of
the plate ; and if turned towards the ground it will be found to re-
main opposite the hole, and not to fall until the current of air is
stopped. Even a plate of tin may in this way be suspended by a
current of air ; which at first would be supposed to conjoin with
gravity in forcing it to the ground. When the disk is flexible and
slightly elastic, a heavy sound, and sometimes even a shrill tone,
is produced by the vibrations of the plate.

In explanation of this experiment, M. Hachette says, " The air
is pushed from the mouth A of the tube, towards the orifice E of
the plate ; it strikes the part of the disk opposed to this orifice, and
the mean pressure on that part is greater than the pressure of the
atmosphere. The blown air then takes place of that between the
plate and the disk opposed to it; it moves in this interval with a
velocity decreasing from the edges of the aperture : the elastic force
of this air decreases at the same time, so that its mean pressure
between the plate and the inner face of the disk becomes less than
the atmospheric pressure ; and as this last pressure is exerted on
the whole external face of the disk H, I, this disk, subject at the
same time to the two contrary pressures on its opposing faces,
obeys the greater, and is pushed towards the plate C D.

It is not necessary that the disk, C D, should be near the orifice
E, of the tube A E. Let Fig. 2 be an instrument composed of
a hollow cylinder, C D F G, and a flat border of the dimensions
C" F, or G D". Let a tube, A E, be fixed to the bottom of the
cylinder, the orifice E having a diameter of about three millimeters
(0.12 of inch). If air be blown in at A, against the disk, H I,
in the neighbourhood of the flat border, the disk will be urged to-
wards the orifice E. This instrument is also delineated on a scale
of one half. The disk, with the attached weight, weighs about
12 grammes (184.87 grains), being 54 millimeters in diameter;
the pressure of the atmosphere upon it equals 23 kilogrammes :
from which it follows that, in this experiment, the pressure of the
air blown upon the inner surface of the disk, and the atmospheric
pressure exerted on the exterior of the same disk, only differs from
each other by about one two-thousandth part of the latter. —
AjiJf^ales de Chimiey xxxv. 34.

^. Considerations relative to Capillary Action^ hy M. Poisson. —
M. Dutrochet, whilst explaining his views relative to the cause of
vital movement in plants and animals, stated that if an animal or
vegetable membrane were formed into a bag, having a tube of

B

Mechanical Science,' * 195

glass attached to its aperture, arid were then filled with a liquid
substance, having a strongs affinity for another liquid, into which
the bac^ was to be immersed, it would not only have the power of
absorbinfT the latter liquid into its pores, but also, in certain cases,
of forcinp^ it up to the top, and even oat of the glass tube held in
a vertical position. On this point, a difference of opinion with
regard to the force of capillarity took place : M. Ampere maintain-
ing that capillary action would raise the fluid to the top of the
tube, but not cause its expulsion ; while M. Poisson maintained
that, in certain cases, the latter effect could be produced. The
latter has since then published a note, which we transcribe in part,
from the Annates de Chimie, xxxv. 98.

Suppose that two different fluids, A, B, are contained in a
vessel, and separated the one from the other by a vertical division ;
the heights being in an inverse ratio to the den-
sities, so that the points, a and 6, in the two faces
of the division, and situated in the same horizontal
plane, shall support equal and opposite pressures :
suppose also that the division is pierced with one
or more holes of small diameter, or, in other words,
that it is traversed by several very narrow canals,
as a, b, perpendicular to the two faces, and which
may be regarded at first as filled with air, or any
other fluid.

If the substance of the division exerts upon each of the two
liquids an action superior to the half of that which the liquid has
upon itself, each liquid will enter into the canal «, 6, just as it
would rise above its ordinary level in a capillary tube of the same
size and substance. It would also be urged, by the excess of
pressure which it would exert at the extremity of the canal, against
the elasticity of the included air. When the two fluids have pene-
trated the interior of «, b, the air will be pushed on both sides in
different directions by forces each of which is equal to the primitive
pressure augmented by the corresponding capillary force, i. e. aug-
mented by forces proportional, according to the known theory of
M. Laplace, to double the action of the tube on the liquid, less
the proper action of the liquid itself It will only be in the case
when the capillary force shall be the same on both sides, that the
air, after being compressed to a certain degree, will remain at rest :
for whenever this force preponderates at one end of the canal, the
air will be driven out at the opposite end, and the liquid with the
strongest capillary attraction will entirely fill the canal.

Suppose this liquid to be A, then let us consider the forces which
will act on the portion rt, b^ of this liquid. At the extremity a,
it will be submitted to the attraction of the exterior fluid A : at
the extremity 6, it will be attracted in the opposite direction by the
liquid B. Now the two liquids being different, their attractions
will be unequal, and we will suppose that that of B, on the matter

O 2

196 Miscellaneous Intelligence.

bf A, is greater than that of A for itself. As to the action of tlie
canal on the portion rt, 6, that will be equal, and exerted in con-
trary directions at its two extremities ; it will not, therefore, be
either adverse or favourable to the movement of the fluid in the
canal : and the same will be the case with respect to the pressures
exerted at a and 6, by the external liquids, as long as they are
equal : nevertheless, the action of the canal, and the external
pressures, will prevent the thread of fluid from being broken, so
that it will move without interruption in the direction in which it
is drawn by the greatest attraction, or from a to 6. Hence will
result an elevation of the level of B, and, consequently, an increase
of pressure at the extremity 6, of the passage, and this elevation
"will proceed until the difference of pressure in a and b shall be
equal to that of the attractions exerted by the two fluids A and B,
on the thread a b; this effect will be produced the more rapidly
as the division is pierced with a greater number of passages similar
to that which has been considered.

Now let us examine what would occur if the division were formed
of two others different in their nature, and exactly superposed ; ex-
erting no action on one of the liquids, B for example, and one only
acting on the other liquid. The liquid B will then retain its ori-
ginal position undisturbed ; in consequence of the action it exerts
upon itself it cannot penetrate the canal a 6, just as mercury can-
not escape by a capillary aperture made in a barometer-tube. It
will be the same with A, when that face of the division which exerts
no action upon the liquid is turned towards it ; so that how nu-
merous soever the apertures, the two liquids would, under such
circumstances, remain separate and preserve their original level.
But if the division be turned so that the face which acts upon A
shall be in contact with that liquid, it will penetrate the canal a b
by means of capillary attraction ; ^and the velocity which the liquid
urged by this force may acquire, may make it pass that point in the
canal where the division changes its nature, and even make it reach
the extremity in the liquid B, so that it is possible that the liquid A
should entirely fill the canal a b, as in the case which has already
been examined. Then if we always suppose the attraction of B for
A to be superior to that which A has for itself, the thread a b will
flow into B until the level of the latter is so far altered that the
excess of pressure at b can balance the difference of attractions ex-
erted by the two liquids at a and b.

M. Poisson then observes that, without pretending to assign a
cause, exclusive of all others, for the phenomena of absorption by
vegetable and animal membranes observed by M. Dutrochet, his
object is to show that effects which have at least a great resem-
blance to these important phenomena, may be produced by capil-
lary action conjoined with the difference of affinity existing between
heterogeneous substances without the assistance of electricity, either
moving or quiescent. It appears that M. Dutrochet afterwards

,'\M Mechanical Science, ' " 197

found mineral substances, as a piece of slate, mi^ht be substituted
for the oro^anized tissues ; this beingr the case, the opinion which
refers such effects to a general cause, as capillary attraction, ac-
quires more probability.

3. Novel Use of the Plough. — Mr. Bruckmann states that he has
long thought the plough might be used in levelling roads and
clearing the foundations for fortifications. In 1824 he had an
opportunity of applying it in the construction of a canal required to
furnish a motive force for the service of the rock-salt works of Fried-
richshall. The bed was to have a section of 700 square feet, and it
had been calculated that the excavations would require 200 men for
two years, whereas the king of Wurtemburg wished it to be done
in one year from the spring of 1824.

Three ploughs were employed; the first had two handles, a
coulter, and a share, the latter being in the form of a wedge. This
plough was preferred in the beds and gravelly grounds ; and it was
found advantageous to give it an oscillatory movement by the
handles during its progress. Drawn by eight horses, it could turn
up 25,000 cubic feet of an argillaceous soil, in three hours ; with
ten horses it turned up 19,800 cubic feet of a gravelly soil, in the
same time. This plough was tried in 1815, against fifteen others
of the ordinary kind, in the construction of a watercourse for a
mill ; all the fifteen were quickly broken by the work.

The second plough had two handles and a coulter, but the share
had only one cutting edge, which was rounded and with an ear. It
was made five times as strong as an ordinary plough, and suc-
ceeded well in compact and argillaceous soils, where, with eight
horses and four men, it moved 48,000 cubic feet of earth in three
hours. In case of fracture ten minutes sufficed to change the
coulter and share, and, during the work, 2,300,000 cubic feet of
earth were loosened by it.

The third plough was smaller and fighter, it had two handles, a
coulter, an ear, and a share, the latter lance-shaped. It was used
for excavating the sides of the canal, on which the horses attached
to the first plough found it difficult to walk because of the inclina-
tion. It was worked by ten or twelve men.

To establish an accurate comparison between the work of these
ploughs and that done by the pickaxe and spade, a piece of ground
was wrought solely in the latter manner by six strong working men.
The result of a long trial was the breaking of 150 cubic feet of
ground by each man in nine hours. Comparing this result with
the work of the ploughs, the following are the results: — ^The first
plough did the work of 477 men, the second of 960 men, and the
third that of 50 or 60 men. The canal was finished on April 30th,
1825, the ploughs having saved 32,000 days, according to the
work-day of a labourer. — Bull. Univ. D. vii. 343.

198 Miscellaneous Intelligence.

4. Discovery of Rocks under the Surface of the Sea. — ^The fishers
of the Mcditerrnneaii use an apparatus for the discovery of rocks
beneath the surface in those places where they wish to cast their
nets, which suppHes, in a great measure, the insufficiencies of the
ordinary means of taking soundings. The method consists in
carrying a long and thin cord over the bottom to be examined, and
which, when it meets with an obstacle, is stopped by it and becomes
folded in the place where it occurs. It will easily be understood,
that when a cord has been carried over a certain space without
meeting with any resistance, that proof is obtained of the non-exist-
ence of rocks or other obstacles, at a depth less than that to which
the cord has been sunk ; and as the examination can easily be car-
ried on to 100 feet below the surface, it may be said that, wherever
such an apparatus has passed unimpeded, the navigation is free.
If, on the contirary, some isolated rocks are found during the exa-
mination, the place where the cord becomes doubled points out the
locality, which may then be determined more accurately by other
trials, and the summit and neighbourhood of the submersed rocks be
accurately examined by means of sonndings.^^ Ann^ales Marit.;
Bull. Univ. F. viii. 44.

5. Paper to resist Humidity. — This process, which Is^flttft tb
M. Engle, consists in plunging unsized paper once or twice into a
clear solution of mastic in oil of turpentine, and drying it by a
gentle heat. The paper, without becoming transparent, has all the
properties of writing-paper, and may be used for the same purposes.
It is especially recommended for passports, workmen's books, legal
papers, &c. When preserved for years it is free from injury, either
by humidity, mice, or insects. It is further added, that a solution
of caoutchouc will produce even a still better effect. — Kunst und
Gewerbe-hlatte.

6. Professor Amides Microscopes. — This distinguished personage
has lately exhibited to the savans of this country two microscopes
of his own workmanship, — an achromatic refractor, and a reflector
of his own particular invention. The object-glass of his refractor
is of a very complicated construction, and is composed of three
double-object glasses combined together in the space of about au
inch. The flint-glass from which his concaves are formed is of the
manufacture of Frauenhofer; his convexes are of Dutch plate,
crown-glass, and French plate, separately. Each object-glass
detached has but a small aperture, and is of long focus ; but when
the three are combined together, the angle of aperture is very
considerable, and the focus short. By this ingenious arrangement
the trouble and difficulty of manipulating deep single-object-glasses
of large aperture is avoided ; but advantages gained one way, in
practical optics, are generally lost in another, and the twelve sur-
faces of the objective produce a kind of soilness and muddiness in

Mechanical Science. 199

the imao^e strongly contrasted by the effect of a good sinj^le triple-
j^lass of equivalent power. When, however, only two of the object-
glasses are combined, the effect is very fine. Between the object-glass
and eye-glasses is placed one of those prisms originally invented by
Sir I. Newton to act as an eye-piece of his telescope, and of which
a description may be seen in his correspondence at the end of Dr.
Gregory's Optics. The utility of the introduction of this device
appears very questionable in an instrument already so complicated.
The diversion of the rays into a course at a right angle to their
original progress (merely to give an horizontal instead of a vertical
position to the body) is surely no warrant for the employment of
two extra refracting surfaces and one reflexion, which cannot fail to
have a pernicious influence on the formation of the image. An
horizontal position of the body is attained with the utmost facility
by a proper construction of the mounting, &c. Setting aside the
dulness of the image produced by the numerous refractions, the
performance of the instrument on test-objects was highly respect-
able and satisfactory.

The reflector is a modification of the original construction recom-
mended by the Professor, who seems to have profited by the school-
ing he received from Dr. Goring, and now sails much closer to the
wind than he did. His objective metal is now two inches focus,
with an aperture of 1^ inch ; but half an inch is cut off for the
purpose of preventing the bad effect of the marginal rays, so that
only 1 inch of the central portion of the metal is employed ; — the
diameter of the diagonal mirror is also reduced to its proper stand-
ard, by which means the blot in the centre of the visual pencil is
rendered as small as possible. It may be asserted of this instru-
ment, that it does as much as can possibly be expected from an
objective part of 2 inches focus, showing many test-objects faintly,
and with much effort; but it is totally unable to compete with
deeper ones equally perfect and of the same angular opening.
The Professor has, in some of his instruments, reduced the focus of
the elliptic metal to ^ inch, and will, no doubt, gradually slide
into the adoption of that radical reform in his instrument, so hap-
pily carried into effect in this country by Dr. Goring, in conjunc-
tion with Mr. Cuthbert, — at least if the figuration of elliptic metals
of -j^(f inch focus with -^^ inch of aperture shall not surpass his
powers of execution. During the Professor's stay in this country
there was a grand field-day at his hotel, at which both his micro-
scopM were tried ai^ainst the Goringian modijication of the reflector,
the superior weight of metal of which completely beat every thing
opposed to it. For the honour of the Professor it must be stated,
that he admitted this defeat with great candour and good sense,
and even had some difficulty in believing in the identity of some of
the objects used, so differently was the ordinary apparent structure
developed by the English improvements on his instrument. It
may with safety be averred that no refractor, at least, will ever be

200 Miscellaneous Intelligence.

made to surpass Dn Goring^s improved Amician Engiscope; and it
seems equally certain that no other reflector will ever be invented
capable of the same facilities of application to the examination of
both opaque and transparent objects. If Professor Amici has been
beaten, it has been done with his own weapons, — the copy has sur-
passed the original, — the child, by virtue of foreign nursing and
tuition, has exceeded the stature and strength of the father.

1. On the Specific Heat of Gases, by MM. de la Riv^ 4ind Mar-
cet. — The principle on which these philosophers proceeded in their
researches, was, to expose equal volumes of different gases to an
equal source of heat during equal times, and to judge, by the aug*
mentation of elastic force in each gas, the temperature which it had
acquired. The apparatus was a kind of manometer, and consisted
of a glass balloon to retain the gas, and a bent tube attached to it,
which, descending into a vessel of mercury, served to show, by the
column of metal within it, what was the elasticity of the gas.
This method was adopted, because, i. The gas was not altered in
volume by the change of temperature, its elasticity only changing ;
ii. The temperature was indicated by the gas itself, and not by a
thermometer : iii. Water was easily separated previously from the
gases, and excluded from the apparatus : iv. All the gases were
placed in exactly the same circumstances, so as to render it unne-
cessary to refer to any calculation for the purpose of comparison.

Two methods of applying heat were resorted to : in one the bal-
loon, containing the gas at a certain temperature, was placed in
water at a higher but constant degree, for a certain time (generally
4''), and the elevation of temperature noticed : in the other, the bal-
loon with the gas was inclosed in a larger copper balloon, blacken-
ed inside, and the space between the two exhausted as much as
possible of air ; the apparatus being then immersed in warm water,
the heat gained access slowly to the gas, and the time] of each
experiment was increased, at the same time that certain sources
of error were avoided.

The gases experimented with were, atmospheric air, oxygen,
azote, hydrogen, carbonic acid, olefiant gas, oxide of carbon, ni-
trous oxide, nitrous gas, sulphuretted hydrogen, ammonia, sul-
phurous acid, muriatic acid, and cyanogen. Great care was taken
in their preparation. The result of the experiment was very unex-
pected ; for, during the five minutes allotted for each, all had ac-
quired the same temperature, — a circumstance which proves that
they all have the sa7ne specific heat The equal volumes of gas at
the pressure of 65 centimeters (15.59 inches) and the temperature
of 20° C, being exposed to a source of heat at 30° C, acquired a
mean temperature of 6.32 degrees in five minutes, the extreme dif-
ference, in any of the experiments, not being more than 0.04 of a

Chemical Science. 201

degree. One gas only forms an exception to the above statement,
namely, hydrogen, which was always heated more than the others,
namely, to 6.6 degrees in the five minutes. This effect is con-
sidered as due not to any difference in specific he*ti ]Mit»t4^)ia differ-
ence in conducting power. '■, <■')[■ .,',<\ pijd 71

Experiments were then made with dilated gase& to ascertain
whether dilatation caused any change in capacity, and it was found
to diminish slowly but regularly with the diminution of pressure.
These results, with a third which is also interesting, have been thus
generally expressed by the authors at the end of their memoir.

i. All gases in equal volumes, and at the same pressure, have
the same specific heat.

ii. Other circumstances being the same, the specific heat of gases
diminishes with diminution of pressure, and equally for all the
gases : the progression converges slightly and in a ratio much less
than that of the pressures.

iii. Each gas has a different conducting power, i.e., all the gases
have not the same power of communicating or receiving heat. —
Ann. de Chimie, xxxv. b» ,j.. -. .<!.,

2. On the Incandescence and Light of Lime. — The* experiments
made by Lieutenant Drummond upon the light of lime and other
earths when highly ignited, with the highly interesting application
which he has made of that emitted from lime, to the purpose of
geodesical surveys, has induced M. Pleischel to repeat and vary the
results. He states that the utmost light is given by lime; the earth
being pulverised and exposed on burning charcoal to the heat ex-
cited by a jet of oxygen falling upon it. He endeavours to account
for the effect, by supposing a kind of pulverulent atmosphere disen-
gaged from the lime at the high temperature used, and considers
that the substances which are competent to emit molecules only in
the gaseous state, cannot produce this intense ligli^^^—^^fil^hrift
far Physik, &c. ,,4^. . ^j^ lo siiH^.^.^ '

3. Evolution of Heat during the Compression of Water. May
14, 1827. — M. Arago announced to the Academy of Sciences, that
M. Despretz had ascertained experimentally, that the compression
of water by a force equal to 20 atmospheres, caused the disengage-
ment of one sixty-sixth part of a degree of heat.

4. On Electrical Excitation. — M, Walcker affirms positively from
experiments made with great care, that three bodies of different
exciting power are necessary in every case of excitation of electri'^
city by contact, and that all the phenomena of this kind are subject
to this condition. If, for instance, two portions of the same metal
being put in contact, electricity is produced, it is because there are
three different states of temperature brought into play, one being
the result of the other two, and a mean between them. One fact
which more than any other sanctioned this idea, was, that the elec-

202 Miscellaneous Intelligence.

trie currents were the more apparent as this third state of tempera-
ture was made more sensible.— jB?^?/. Univ., A. vii. 374.

5. Magnetic Repulsion. — A very remarkable result has been ob-
tained by M. Becquerel, from the use of an extremely delicate
magnetic arrangement, which he has for the present called a sidero-
scope. Its use is exactly the same in principle as that of the
magnetic needle, indicating iron, for instance, by the attraction
manifested ; but it is so delicate that it will show it in the most mi-
nute quantity possible, as, for instance, in gold, silver, or copper
money, innumerable minerals, &c. This instrument shows no mag-
netic power or attraction in gold, silver, copper, palladium, tin,
lead, zinc, or brass, when chemically pure, and a great many vege-
table and mineral substances have no action on it : but the most
curious result is, that very pure bismuth and even that of commerce
has a repulsive power, which, if it be found ultimately to be inde-
pendent of any magnetic polarity, is the first fact of the kind that
has been made known. Antimony also presents the same pheno-
menon.

6. Diminished Solubility of Substances by Heat. — Mr. Graham
has added one to the few facts of this kind with which we were
acquainted, and has accompanied its description with some very
interesting considerations, which may be found at length in the
Philosophical Magazine, N. S., ii. 20. The salt experimented
with by Mr. Graham is the phosphate of magnesia ; which may be
prepared by mixing a solution of 21 parts of phosphate of soda
with one of 15.375 parts of sulphate of magnesia : within 24 hours
the phosphate of magnesia precipitates in acicular crystals ; they
should be agitated with repeated portions of water, then thrown
upon a filter with more water, and left to dry.

Solutions were obtained by occasionally agitating this salt with
water in the proportion of 2 ounces to a pint of the fluid, for four
days ; being then decanted and filtered, they had a sweetish taste.
A quantity of this fluid being heated in a water-bath, became turbid
before the temperature had attained 120° F. ; at 212° a cloudy
precipitate slowly subsided, and the supernatant fluid became nearly
transparent. The precipitate was found to be anhydrous phosphate
of magnesia ; and, by further experiment, the difference in solubility
was found to be such, that water at 45°, dissolving y-J^th part its
weight of the anhydrous salt, water at 212° only dissolved itVt*^^
part. When in the state of crystals, or as hydrate, the proportions
of salt were ^^ and ■^-}j-^ to 1 of water.

Mere continuance of the heat had no effect in increasing the
precipitate either of this salt, or from aqueous solution of lime,
provided no part of the solution was at any time converted into
vapour; but if the solution only occupied a small part of the vessel,
and ebullition came on, then, although all the water might be re-
turned to the solution, yet the precipitation went on, and might be

Chemical Science. S03

Increased ad Hhitum, particularly in the case of Hme water. The
cause of the precipitate appears to be the same in all these cases.
The moment a drop of the solution is converted into vapour, it de-
posits the quantity of lime or salt which it held in solution ; and in
the case of bodies which dissolve so sparingly and with so much
difficulty, althouj^h the water be returned again to the solution, it
is incapable of re-dissolving what it has deposited. We know that
it would be a hopeless task to form a saturated solution of lime by
agitating with the water no more than the few grains which it is
capable of dissolving ; and in the case of ebullition, when the lime
is once deposited, there should be the same difficulty in taking it up.
' Mr. Graham states that he has observed this effect not only in
lime-water and in solution of phosphate of magnesia, but to a cer-
tain extent in all bodies of difficult solubility, in the sulphate of
lime, for instance, even when greatly diluted; and he believes that
the deposite from slight boiling observed in many mineral waters,
and generally attributed to the dissipation of carbonic acid gas,
depends, in some instances, upon this cause. However weak the
solution may be, it is evident that a portion of the salt may be de-
posited in this way.

7. On the Composition of Cyanic Acid. — M . Wohler some time
since announced the production of cyanic acid, and cyanates, corre-
sponding in composition to the substance presumed to exist in the
fulminating compounds of silver, mercury, &c., the nature of which
was made out by MM. Liebig and Gay Lussac. M. Liebig, upon
repeating M. Wohler's experiments upon his cyanate of silver, ob-
tained only 71.012 per cent, of oxide of silver, instead of 77.23,
which was the quantity present according to M. Wohler's analysis,
and Concluded that the acid was the cyanous, and not the cyanic.
The latter philosopher was consequently induced to repeat his ex-
periments: one of his methods of decomposing the cyanate of silver
was by muriatic acid gas : at first liquid cyanic acid forms, which is
very soon transformed into a white crystalline mass ; but, on con-
tinuing the operation, and applying a higher heat, a large quantity
of muriate of ammonia and cyanic acid is evolved. This process
indicated 77.5 per cent, of oxide of silver in the salt. Another
process consisted in dissolving the cyanate in nitric acid, and pre-
cipitating the silver by muriatic acid, the result was 77.05 of oxide
per cent. A third analysis, made by reducing the silver of the salt,
gave a result of 77.35 per cent, oxide. The mean of these is 77.3,
and the theoretical number obtained by calculation is 77.23, so
that the acid appears to be truly the cyanic ; and the curious fact of
its being the same in composition with that in the fulminating com-
pounds of silver and mercury, but very unlike in properties, still
remains undisturbed. — Bull. Univ.y A. viii. 53.

8. lodous AQid.—'A.ccordmg to M. Wohler, the iodous acid of

20-i Miscellaneous Intelligence.

M. Sementini* is nothing- more than a mixture of chloride of iodine
and iodine. When saturated with carbonate of soda, the iodine in
sohition is precipitated, and on evaporating the solution to dryness,
and heating" it strongly, the residue fuses, and by proper tests is
found to be a mixture of chloride and iodide of sodium.

These statements apply only to the iodous acid : as to the oxide
of iodine, no source of chlorine exists in the process last described
by M. Sementini. ^ ^ ^ •'

9. On Maiiganesic Acid, hy M# Unverdorben. — When manga-
nesate of potash is distilled with a little anhydrous sulphuric acid,
manganesic acid is evolved in the form of a red transparent gas,
which dissolves in water, forming a red solution. The gas fre-
quently decomposes spontaneously in the retort, with explosion,
producing oxide of manganese and oxygen.

Manganesate of potash was analysed by distilling it with excess
of sulphuric acid, collecting the oxygen disengaged, and estimating
the proportion of protoxide of manganese and salts of potash re-
maining in the retort. According to these experiments the acid
consistsof Manganese . 58.74

Oxygen .41.26

...iHip'^iiU i.; i^5 100.00

And the mangajiesate of potash of Or being calcined

Potash . . 25.63 . . 32.75

Manganese acid . 52.44 . , 67.25

Water , . 21.93

100.00

100.00

Ann, des Mines, 1827, p. 145.

10. Heavy Muriatic Ether, and Hydrocarhuret of Chlorine or
Chloric Ether. — Some comparative experiments have been made on
these two substances by M. Vogel. He prepared the former of
them by passing chlorine gas into alcohol. The muriatic acid was
then separated by distilling the fluid from off chalk, in which opera-
tion the muriatic ether and alcohol passed over together, and these
were divided by the addition of water, which dissolved the latter,
and left the former. The chloric ether was made as usual from
chlorine and olefiant gases. The results that were obtained by
acting on these substances by a high temperature, potash, phos-
phorus, &c., induced M. Vogel to consider them as identical in
composition, notwithstanding some differences in their physical
properties ; the specific gravity of the muriatic ether was 1.134,
that of the chloric ether 1.214, and the odour of the latter is more
aromatic, and the taste more sweet than of the former.

Whilst passing the chlorine into the alcohol, M. Vogel observed

* See the last volume of this Journal, p. 477.

Chemical Science. \ 205

that if the sun shone upon the substances when the action was
nearly complete, each bubble of chlorine as it entered the alcohol
produced a brig-ht purple iiame, a dense white vapour, and caused
violent concussions in the liquid; another curious instance, in addi-
tion to the many that are known, of the power of solar ligiit over
chemical action. — Journ, de Pharm. 1826, p. 627'4:jLrfs.B)3 <

11. Test for the Presence of Nitric Acid. — The following method
is one devised by Dr. Liebi^, for the detection of this substance,
which it will effect, he says, when there is not more than a four-
hundredth part of the acid present. The liquid to be examined
must be mixed with sufficient sulphuric solution of indig-o to acquire
a distinct blue colour, a few drops of sulphuric acid added, and the
whole boiled. If the liquid contains a nitrate, it will be bleached,
or, if the quantity is very small, rendered yellow. By adding' a
little muriate of soda to the liquid before applying heat, a five-
hundredth of nitric acid may easily be discovered. — Ann, de Chimicy
XXXV. 80.

12. Peculiar Formation of Nitre. — ^The leaves and stems of beet
root contain oxalate and malate of potash. Some leaves were tied
tog-ether and hung- up in a warm and slightly-humid place, where
there was but little light, to dry. Being examined at the end of
several months, they were found penetrated with, and covered by,
an immense number of minute crystals of nitre. The oxalic and
malic acids had been replaced by nitric acid ; but whether from
animalized matter naturally in the leaves of the plant, or from the
action of the air, or in what manner, is not known. — M. Henri
Braconnot, Ann. de Chimie, xxxv. 260.

13. Experiments on Fluoric Acid and Fluates, by M. Kuhlman,
—These experiments were made with dry sulphuric acid and fluor
spar, with the intention of proving that fluor spar is truly a com-
pound of fluorine and calcium, and not of fluoric acid and oxide
of calcium. A quantity of anhydrous sulphuric acid was prepared
with great care, and collected in a glass tube ; the latter was then
connected with a platina tube charged with fluor spar, which had
previously been calcined in a platina crucible, and a glass tube was
connected with the other end of the platina tube for the purpose of
conducting and facilitating the collection of the gas evolved over
mercury. The fluor spar was heated to redness, and then the tem-
perature of the sulphuric acid raised so as to cause a stream of it
in vapour to pass over the fluor spar ; but there was not the sHghtest
reaction, the sulphuric acid recondensed in part in the farthest tube,
and no trace of fluoric acid was produced. Dry sulphuric acid was
then put, in the liquid state, in contact with dry fluor spar, but
there was no decomposition, and no portion of the spar was con-

206 Miscellaneous Intelligence,

verted into sulphate of lime. The first experiment was then re-
peated, with the difference of using" hydrated sulphuric acid of
specitic gravity 1.842, and there was instantly much fluoric acid
produced, which acted upon the glass.

As Berzelius found 100 parts of fluor spar, when acted upon by
sulphuric acid, to yield 175 parts of sulphate of lime, equal to
73.553 parts of lime, or 52.819 of calcium, it follows that 100
parts of fluoride of calcium should contain 47.181 of fluorine and
52.819 of calcium. By the assistance of this result, and further
experiments, M. Kuhlman proceeded to ascertain the composition of
hydro-fluoric acid. Dry muriatic acid gas was passed over cal-
cined fluor spar heated to redness in a tube of platina ; the fluoride
of calcium was decomposed, free hydro-fluoric acid was evolved,
and chloride of lime remained in the tube. The hydro-fluoric acid
acted upon the glass tubes, but being received in water was entirely
dissolved, with the exception of the silica it had separated from
the glass : no trace of hydrogen appeared. One hundred parts of
fluoride of calcium thus treated became 143.437 parts of chloride
of calcium, the 52.819 parts of calcium having united to 90.598
parts of chlorine. But this latter quantity must have liberated
2.511 parts of hydrogen, which must, therefore, have combined with
the 47.181 parts of fluorine in the spar, to form 49.692 parts of
hydro-fluoric acid. This latter body, therefore, consists of 94.941
fluorine, and 5.059 of hydrogen per cent. A small quantity of
chlorine was set at liberty during the experiment, the author thinks,
from a little manganese in the fluor spar.

M. Kuhlman found that all the chlorides, when subjected to the
action of anhydrous sulphuric acid in vapour, resisted decomposi-
tion, except the chloride of sodium, which gave a small quantity
of sulphate of soda, and a double salt of soda and platina, crys-
tallizing in fine needles of a yellow colour. No doubt is enter-
tained that, in the latter case, the common salt and sulphuric acid
were not perfectly dry. — BulL Univ.

14. Crystallization of Phosphorus. — By the fusion and careful
refrigeration of a large quantity of phosphorus, M. Frantween has
obtained very fine crystals of an octoedral form, and as large in
size as a cherry-stone. ; uwwjv, '•

15. Solutions of Phosphorus in Oils. — The solutions of phos-
phorus in fixed oils are so luminous as often to be resorted to for
the exhibition of this peculiar property of phosphorus ; but M.
Walcker has remarked, that the power which they ordinarily possess
is instantaneously destroyed by the addition of small quantities
only of certain other substances, as the essential oils. The rectified
oils of turpentine and amber, the oils of rosemary, bergamotte,
lemon, camomile, angelica root, juniper berries, and parsley seed,

Chemical Science, 207

the oil obtained by the distillation of the nutme|^, all produce this
efTect when their quantity is not more than one-fiftieth part of the
luminous oily solution of phosphorus. The same effect is pro-
duced by adding about a fifYh of the oils of anniseed, cajeput,
lavender, rue, sassafras, fern, cascarilla, mint, orange flowers, fen-
nel, valerian, cherry laurel, or bitter almonds, or balsam of copaiba;
but the oil of cinnamon, rectified petroleum, balsam of Peru, and
caiQphor» have np such effect. — Anrud, der Phys, 1826, p. 125.

16. On the Injlammation of Powder when struck by Brass, 8fc,
— Iron has been excluded from powder-works as subject to cause
sparks by a blow, and brass and copper have been recommended
in its place. M. le Col. Aubert has remarked, that brass on brass
can inflame powder, and has made experiments on the subject
before a committee, the result of which is as follows : — Inflamma-
tion of the powder takes place when the blow is given by iron
against iron ; iron against brass ; brass against brass ; iron against
marble ; lead against lead, or against wood, when the blow is pro-
duced by a leaden ball shot from a fire-arm. As yet the powder
has not been inflamed by the blow of an iron hammer against lead
or wood. — Bull, de la Sac. d' Encouragement; Bull, Univ,

17. Cementation of Iron by Cast Iron. — Pure iron, when sur«?
rounded by, and in contact with, cast iron turnings, and heated,
is carbonised very rapidly, so as to harden, to temper, and, in fact,
to exhibit all the properties of steel. M. Gautier finds this a very
advantageous process in numerous cases, especially where the arti-
cles to be case-hardened, or converted into steel, are small, as iron
wire, or wire gauze. The temperature required is not so high as
that necessary in the ordinary process of cementation, and the
pieces to be carbonised are not injured in form. The kind of cast
iron used should be the gray metal, and the more minutely it is
divided the more rapid and complete is the operation. By cover-
ing the mass of cast metal, in which the iron to be carbonised is
enveloped, with sand, oxidation, from contact of the air, is prevented,
and the cast metal may be used many times. Plumbago experi-
mented with in the same manner does not produce the effect. —
Jour, de Pharmade, 1827, p. 18.

18. On the Preparation of Ferro-prussiate of Potash, by M,
Gautier. — Numerous investigations induced M. Gautier to conclude,
that, i. When animal matter is calcined alone it yields but little
cyanogen, ii. That when mixed with potash it gives more, but the
cyanuret is not ferruretted. iii. That ammonia is then produced in
large quantity, iv. That the substitution of nitre for potash, and
the addition of iron or scales of iron, augmented the production
of cyanogen, and gave a ferro-prussiate. The following is the
process of manufacture to which M. Gautier has ultimately arrived,

20S Miscellaneous Intelligence.

and which he has practised for some years. The proportions of
the materials are —

Blood, considered as in the dry state, 3 parts
. Nitre 4 •<« U o'^u^h^i^i^ 'y , 1 part

Iron scales , ' . * : tV of the blood employed.

The blood is first to be coagulated in a large copper cauldron, and
the serum being separated by means of a press, the coagulum is
to be returned to the cauldron with the nitre and iron. The quan-
tity of water contained in the blood is sufficient to liquify the salt,
so as to allow of an uniform mixture being etfected. The mixture
is then removed, and exposed in an airy situation to dry, the putre-
faction of the blood being prevented by the nitre. When the de-
siccation is complete, the mixture is charged into cast iron cylin-
ders, which are fixed in a reverberatory furnace, and in all things
resemble those used in the preparation of animal charcoal. These
are to be raised to a brown red heat, until no more vapour is dis-
engaged, and then left until nearly cold, after which the contents
are to be withdrawn and put into a wooden vat, with twelve or fif-
teen times their weight of water, for an hour. The fluid is then
to be filtered through a cloth, and evaporated until of 32° of Beaue
(specific gravity 1.284.) Being then left to cool, a large quantity
of well-crystallized bi-carbonate of potash is obtained. M. Gautier
Says he has not, as yet, been able to explain how it is that this
bi-carbonate has been formed at so high a temperature ; a portion
also appears to be decomposed during the evaporation of the solu-
tion, which, at first but slightly alkaline, becomes sensibly so by a
prolonged evaporation.

As the same product is not obtained when potash is used in place
of nitre, it is probable that the elements of the nitric acid perform
a particular part in the operation.

The solution which has given the crystals of carbonate of potash
contains a little carbonate of potash, and much ferro-prussiate of
potash. It is to be concentrated to 34° (specific gravity 1.306), and
placed in wooden vessels lined with lead. In the course of some
days a greenish crystalline mass is obtained, which being redis-
solved in a fresh quantity of pure water, and evaporated to 32*^ or
33° (specific gravity 1.295), is to be recrystallized.

Sometimes, when using potash, M. Gautier has mixed nitre with
it, and has always obtained a richer product than when potash alone
had been employed. — Jour, de Phar. 1827, p. 11.

19. Sulphocyanide of Potassium in Saliva. — MM. Tiedemann
and Gmelin have observed the existence of this peculiar compound
in saliva, in two cases ; the one when the fluid was secreted during
smoking, and the other when no such stimulus was ^ppHed. — Ann.
de Cliimie, xxxv. 266.

20. Decomposition of Sulphate of Copper by Tartaric Acid.-^

Chemical Science, ' 209

M. Planche has observed, that when sulphate of copper is dis-
solved ill wine vincg\ir, for the ])urj)ose of ])reparin^ a corrosive
liquid to be applied to corns on the feet, that the tartaric acid pre-
sent in the vineg-ar displaces the sulphuric acid from a part of the
salt, an^ an. insoluble acid tartrate of copper is produced.
.iHvir.'i.*..- • M'i; -'i. ..' .,••■■■ ^" ■. • : ■■(■-; ;'...••

2liu^$eparatton of Arsenic from Nichd or Co6«Z<.--*-The following
process by M. Woehler seems among the best of those intended
for freeing nickel or cobalt from arsenic in the dry way. • It is
founded upon the circumstances that many alloys, when heated with
sulphuret of potash, become changed into a mixture of sulphurets,
and that sulphuret of arsenic is very soluble in sulphuret oi^>otash.
One i)art of kuplernickle, fused and reduced to fine powder, is to be
mixed with 3 parts of carbonate of potash, and 3 parts of sulphur, in a
covered Hessian crucible. The heat is to be gradually raised to
redness, and until the mass is just entering into fusion, and by no
means so highly as to fuse the sulphuret of nickel which is formed.
When cold, water is to be added, which will dissolve the sulphuret
of potash, and leave a yellow crystalline powder, which is sulphuret
of nickel, retaining, perhaps, a little copper or cobalt, but no arsenic,
if the operation has been well performed. When, however, the
object is to have the nickel perfectly pure, it should be fused a
second time with sulphur and potash.

The method of freeing cobalt from arsenic, is the same as for
nickel ; but it is then necessary to perform the operation a second
time. The cobalt (that of Tunaberg) has never been perfectly freed
from arsenic by one operation, but has never retained any after the
second. — Archiv filr BergbaUy 1826, p. 186.

22. Compounds of Gold. — According to late experiments of Dr.
Thomson, peroxide of gold consists of

1 atom gold 25

3 „ oxygen a,i.i,.<u -

28
and is consequently a teroxide. Muriate of gold consists of.

,3 , atoms muriatic acid 9.25 ,.

, X.i .». per oxi.cl^.,9f gftl4 ,,,,.. 28 .
5 „ watei^;^ I *w'^^l#Hb».-«i«:>W-.fty :^ • ^25

/ < i 11 ' Edin. Jowrntd, p. 1 82.

23. Chemical 'Re^searches rclaiive to certain Ancieiit Substances.—^
M. Vauquelin has analyzed, i. A poignard blade formed of copper
only; ii. A mirror, which was found to consist of 85 parts of copper,
14 of tin, and 1 of iron per cent. ; iii. A blue colour found in a tomb:

JUNE — OCT. 1827. P

210 Miscellaneous Intelligence.

it was composed of silica 70 parts ; lime 9 ; oxide of copper 15 ;
oxide of iron 1 ; soda mixed with potash 4. A blue identical with
this, both in colour and composition, was found in the bottom of a
furnace in which copper had been fused at Romilly.

M. D'Arcet has examined a bone from the fore part of an ox,
which had been placed as an offering to the divinity in an Egyptian
tomb, and found that it contained as much gelatine as recent bone,
although rather less is obtained by muriatic acid, (20 per cent,
instead of 27) because of a deterioration of the bone. When burnt,
it gave an animal black as deep in colour as that from recent bone.

M. Le Baillif has examined some grains of corn, which were so
well preserved, that when put into boiling water iodine produced
the blue colour dependent upon starch. He also made some ex-
periments on a gummy substance, and on two cords from a musi-
cal instrument; the latter were of animal substance.

M. Raspail examined some grain which was supposed to be
wheat, but found it to be torrified barley ; it was covered with a
substance communicated probably by the oil and incense with which
the grains were bathed when consecrated. Similar grains were ob^
tained by roasting common barley.

The account of most of these researches is given in the Catalogue
raisonne et historique des Antiquites decouvertes en Egypte, by
M. Passalacqua. — Bull. Univ. A. vii. 264.

24. On the Bitter Substance produced hy the action of Nitric
Acid on Indigo, Silk, and Aloes, by M. Just Liebeg. — ^The process
by which M. Liebeg obtains a pure and uniform substance from the
action of nitric acid on indigo, is as follows : — A portion of the best
indigo is to be broken into small fragments, and moderately heated
with eight or ten times its weight of nitric acid of moderate strength.
It will dissolve, evolving an abundance of nitrous vapours and
sweUing up in the vessel. After the scum has fallen, the liquid is
to be boiled, and nitric acid added, whilst any disengagement of red
vapours is occasioned by it. When the Hquid has become cold, a
large quantity of semi-transparent yellow crystals will be formed,
and if the operation has been well conducted, no artificial tannin or
resin will be obtained. The crystals are to be washed with cold
water, and then boiled in water sufficient to dissolve them. If any
oily drops of tannin form on the surface of the solution, they must
be carefully removed by touching them with filtering paper. Then
filtering the fluid, and allowing it to cool, yellow brilliant crystalline
plates will be obtained, which will not lose their lustre by washing.

To obtain the substance perfectly pure, the crystals must be re-
dissolved in boiling water, and neutralized by carbonate of potash.
Upon cooling, a salt of potash will crystallize, which should be
purified by repeated crystallizations.

On mixing the first mother liquor with water, a considerable
trown precipitate will be obtained, which being dissolved in boiling

Chemical Science. 211

water, and neutralized by carbonate of potash, will furnish a larp^e
quantity of the potash salt. All the potash salt obtained in thes6
operations is to be re-dissolved in boiling water, and nitric, muriatic,
or sulphuric acid added ; as the solution cools, the peculiar sub-
stance will be observed to form very brilliant plates of a clear yellow
colour, generally in equilateral triangular forms.

Sometimes crystals are not formed after the action of the nitric
acid on the indigo, in which case the liquor must be evaporated,
and water added, when the substance will precipitate, and must be
purified as already described. Four parts of indigo yield one of the
pure substance.

When the substance is heated, it fuses, and is volatilized without
decomposition ; when subjected to a sudden strong heat, it inflames
without explosion, its vapours burning with a yellow flame, and a
carbonaceous residue remaining. It is but little soluble in cold
water, but much more in boiling water ; the solution has a bright
yellow colour, reddens litmus, has an extremely bitter taste, and
acts like a strong acid on metallic oxides, dissolving them, and form-
ing peculiar crystallizable salts. — Ether and alcohol dissolve the
substance readily.

When fused in chlorine or with iodine, it is not decomposed, nor
does solution of chlorine affect it. Cold sulphuric acid has no
action on it ; when hot, it dissolves it, but water separates the sub-
stance without alteration. Boiling muriatic acid does not affect it,
and nitro-muriatic acid only with great difficulty.

These results show that no nitric acid is present in the substance^
and other experiments prove that no oxide of nitrogen exists in it ;
it contains no oxalic or other organic acid, for when its salt is boiled
with chloride of gold, the latter is not reduced.

When heated to redness with oxide of copper, it gave a mixture
of nitrogen and carbonic acid, in the exact proportion of 1 volume
of the former, to 5 of the latter. This was a constant result, and
in no case was any sulphuric or muriatic acid left in the copper.
0.0625 grammes of the substance thus decomposed, gave 45 cubic
centimeters of the mixed gases, estimated at 0°C. (32° F.) and the
pressure of 28 inches of mercury, according to which the acid would
be composed of carbon 32.392 ; nitrogen 15.2144 ; oxygen 52.3936
per cent. From the mean of several experiments, it appeared that
the following might represent the composition correctly. —

12^ atoms of carbon ... 93.75 or 31.5128

2| „ azote . . . .43.75 „ 14.7060

16 „ oxygen . . .160.00 „ 53.7812

297.5 100.

100 parts of the acid neutralize a quantity of base equivalent to
3.26 of oxygen, which is to the oxygen of the acid, as 1 : 16 ; the
equivalent number of the acid derived from the analysis of the

P 2

212 Miscellaneous TnfcUigence.

barytic salt was 306.3 ; by adding only J- ])cr cent, to the quantity
of baryta obtained in the experiment, 297.5, or the number cxt
pressed by the above, formula, would be obtained.

When a salt of potash or baryta was decomposed by oxide of
copper and heat, the quantity of carbonic acid produced was a little
short of five times the quantity of nitrogen ; but, upon adding- that
retained by the alkali or earth,, tbeprpportioa became exactly the
same as in the former cases. ...

Welter's hiiter principle was prepared by acting; on silk with ten
or twelve times its weight of nitric acid. The liquid, slightly co-
loured at first, acquired a deep yellow upon adding water. It was
neutralized by carbonate of potash whilst hot, and left to cool, and
the salt of potash thus obtained, decomposed by muriatic, nitric, or
sulphuric acid. This acid, crystallized like that from indigo, formed
the same salts, and was composed in the same manner. Silk fur-
nishes much less of the substance than indigo. Dr. Liebeg has
called this substance carhazotic acid. The most important salts
formed by it have the following properties : —

Carhazotate of Potash — crystallizes in long yellow quadrilateral
needles, semi-transparent and very brilliant ; it dissolves in 260
parts of water at 59° F., and in much less, boiling water : a satu-
turated boiling solution becomes a yellow mass of needles, from
which scarcely any fluid will run. Strong acids decompose it ; yet
when an alcoholic solution of carbazotic acid is added to a solution
of nitre, crystalHzed carbazotate of potash, after some time, preci-
pitates. — Alcohol does not dissolve it. When a little is gradually
heated in a glass tube, it first fuses, and then suddenly explodes,
breaking the tube to atoms ; traces of charcoal are observed on the
fragments. This salt precipitates a solution of the protonitrate of
mercury, but not salts, containing the peroxide, or those of copper,
lead, cobalt, iron, lime, baryta, strontia, or magnesia. The slight
solubility of this salt supplies an easy method of testing and sepa-
rating potash in a fluid. Even the potash in tincture of litmus may
be discovered by it ; for, on adding a few drops of carbazotic acid,
dissolved in alcohol, to infusion of litmus, crystals of the salt gra-
dually separated. The saturated solution of the salt at 50° F., is
not troubled by muriate of jjlatina. The salt contains no water of
crystallization. It was analyzed by converting a portion of it into
chloride of potassium by muriatic acid: its composition is, —

Carbazotic acid ....... 83.79

Potash . 16.21

100.00

Carhazotate of Soda — crystallizes in fine silky yellow needles,
having the general properties of the salt of potash, but soluble in
from 20 to 24 parts of water, at 59° F.

Carbazotate of Ammonia forms very long, flattened, brilliant,

Chemical Science, 213

yellow crystals, very soluble in water. Heated carefully in a glass
tube, it fuses, and is volatilized without decomposition ; heated
suddenly, it inflames without explosion, and leaves much carbona-
ceous residue.

Carbazotate of Baryta, obtained by heatinjr carbonate of baryta,
and carbazotic acid with water. It crystallizes in quadrangular
prisms of a deep coloin*, and dissolves easily in water. When heated,
it fiiscs, and is decomposed with very powerful explosion, producing
a vivid yellow flame. The explosion is as powerful as that of ful-
minating silver; a solution of chloride of potassium to which car-
bazotate of baryta has been added, produces a precipitate of the
potash salt, and not more than 1^ per cent, of potash remains in
solution'. 100 parts of the crystallized salt contain, —

Carbazotic acid . . 69.16 oxygen of the acid . 16
Baryta .... 21.60 „ earth . 1

Water ..... 9.24 „ water . 8

•>ii;l'~h,!i'p. VMVliV "j 100.00

Carhattftdte 6f Birrtey obtained like the salt of baryta, forms flat-
tened quadrangular prisms, very soluble in water, and detonating
like the salt of potash.

Carbazotate of Magnesia forms very long indistinct needles, of a
clear yellow colour ; is very soluble, and detonates violently.

Carbazotate of Copper, prepared by decomposing sulphate of cop-
per by carbazotate of baryta : it crystallizes with difficulty, the
crystals being of a fine green colour; it is deliquescent; when heated,
it is decomposed without explosion, and even without inflammation.

Carbazotate of Silver. — Carbazotic acid readily dissolves oxide
of silver, when heated with it and water; and the solution, gradually
evaporated, yields starry groups of fine acicular crystals of the
colour and lustre of gold ; the salt dissolves readily in water; when
heated to a certain degree, it does not detonate, but fuses like gun-
powder.

Proto-Carbazotaie of Mercury, obtained in small yellow triangu-
lar crystals, by mixing boiling solutions of the carbazotate of potash
or soda, and proto-nitrate of mercury. It requires more than 1200
parts of water for its solution: for its perfect purification, it should
be heated with a solution of chloride of potassium, the insoluble
portion separated whilst the liquid is lost, and the peculiar salt
allowed to deposit as the temperature falls. When heated, it be-
haves like the salt of silver.

All these salts detonate much more powerfully when heated in
close vessels, than when heated in the air; and it was a curious
thiug to observe, that those with bases yielding oxygen most rea-
dily, were those which exploded with least force) By heating some
of the salts previously mixed with chloride of potassium, &c., to
retard the action, it appeared that no carbonic oxide, but only car-

214 Miscellaneous Intelligence.

bonic acid and azote were evolved during their decomposition by
heat.

Oil the Bitter Principle from Aloes. — Upon distilling 8 parts of
nitric acid from 1 part of the extract of aloes, and adding water to
the remaining fluid, a resinous reddish yellow substance precipi-
tated, which, by washing, became pulverulent — it was discovered
by M. Braconnot. Upon evaporating the liquid separated from the
precipitate, it gave large yellow rhomboidal crystals, not transpa-
rent, and but slightly soluble. These crystals, at first mistaken for
a particular substance, were soon found to be a combination of
oxalic acid with the bitter of aloes. The bitter substances of aloes
dissolved in 800 parts of water, at 59° F., but in a smaller quantity
of boiling water. This solution has a superb purple colour. Silk
boiled in it acquired a very fine purple colour, on which neither
soap nor acids effected any change, except nitric acid ; this changed
the colour to yellow, but it was restored simply by washing in water.
All shades may be given to this colour by proper mordants. Wool
is dyed black in a peculiarly beautiful manner, by the same process,
and light has no influence on the colour. Leather acquires a pur-
ple colour; cotton, a rose colour; but the latter will not resist soap.
Dr. Liebeg thinks that this is the only substance from which a perma-
nent rose dye for silk may be expected. — Ann. de Chimie, xxxv. 72.

25. On the Existence of Crystals of Oxalate of Lime in Plants.— ^
M. Raspail has read a memoir to the Academy of Sciences, to prove
the analogy which exists in arrangement between the crystals of
silica, which are found in sponges, and those of oxalate of lime oc-
curring in the tissue of phanerogamous plants.

The latter crystals were observed, for the first time, by Rafn and
Jurine, who regarded them as organs of which they knew not the
use. They were then observed by M. de Candolle, who called
them raphideSy and gave a figure of them, which, however, is inac-
curate. These crystals are really very regular tetraedrons. In
many plants, as orchis^ pandanus, ornithogahim, jacinthus, phy-
tolaca decandria, mesembryanthemum deltoides, &c. they are very
small, not being more than -g^^ of a millimetre ( . 0002 of an inch) in
width, and ^^y ( . 004 of an inch) in length. But, in the tubercles of
the Florence iris, they are as much as 3^^ ( . 0008 of an inch) in
width, and ^ (.01312 of an inch) in length, so as to be easily ca-
pable of examination. — Bull. Univ. B. xi. 376.

26. Fallacy of Infusion of Litmus as a Test, by M. Magnus. —
When pure water is heated for a sufficient time with infusion of
litmus, reddened by an acid, it restores the blue colour. It is sup-
posed that the heat gradually causes the free sulphuric acid, which
had occasioned the reddening, to combine with the excess of alkali
contained in the infusion, and thus to cause the restoration of the
blue colour. Hence this preparation cannot be used to test the

Chemical Science, 215

presence of ammonia in a solution, as water alone produces the
effect anticipated from the alkali. The earthy salts contained in
ordinary water also produce this effect. — Jour, de Pharmacie.

27. Tests for the Natural Colouring Matter of Wine. — M. A.
Chevalier states, — i. That potash may be employed as a re-agent,
to ascertain the natural colour of wines, which it changes from red
to a bottle green, or brownisli green — ii. That the change of colour
produced by this substance upon wine is different for wine of diffe-
rent ages — iii. That no precipitation of the colouring matter takes
place, the latter remaining dissolved by the potash — iv. That the
acetate of lead should not be employed as a test of the colour of
wines, because it is capable of producing various colours with wines
of a natural colour only — v. That the same is the case with lime-
water, with muriate of tin mixed with ammonia, and with subace-
tate of lead — vi. That ammonia may be employed for this purpose,
the changes of colour which it produces not perceptibly varying —
vii. That the same is the case with a solution of alum to which a
certain quantity of potash has been added, and which may, there-
fore, be used for the purpose. — Annates de V Industrie.

28. Test of the Presence of Opium. — Pr. Hare says he can detect
opium in solution, when the quantity is not more than that given,
by adding ten drops of laudanum to half a gallon of water. The
following is the process : — a few drops of solution