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THE
LONDON and EDINBURGH

PHILOSOPHICAL MAGAZINE

AND

JOURNAL OF SCIENCE.

CONDUCTED BY

SIR DAVID BREWSTER, K.H. LL.D. F.R.S. L. & E. &c.
RICHARD TAYLOR, F.L.S.G.S. Astr.S.Nat.H.Mosc.&c.

AND

RICHARD PHILLIPS, F.R.S. L.&E.F.G.S. &c.

" Nee aranearum sane textus ideo melior quia ex se fila gignunt, nee noster
vilior quia ex alienis libamus ut apes." Just. Lips. Monit. Polit. lib. i. cap. 1.

VOL. XL

NEW AND UNITED SERIES OF THE PHILOSOPHICAL MAGAZINE,
ANNALS OF PHILOSOPHY, AND JOURNAL OF SCIENCE.

JULY-DECEMBER, 1837.

LONDON:

PRINTED BY R. AND J. E. TAYLOR, RED LION COURT, FLEET STREET :

SOLD BY LONGMAN, OBME, BROWN, GREEN, AND LONGMANS; CADELL;

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AND MARSHALL; WHITTAKER AND CO.; AND S. HIGHLEY,

LONDON : BY ADAM AND CHARLES BLACK, AND

THOMAS CLARK, EDINBURGH J SMITH AND SON,

GLASGOW; HODGES AND SMITH, DUBLIN;

AND G. W. M. REYNOLDS, PARIS.

The Conductors of the London and Edinburgh Philosophical Magazine
have to acknowledge the editorial assistance rendered them by their friend
Mr. Edward William Brayley, F.L.S., F.G.S., Corr. Mem. Roy.Geol. Soc.
of Cornwall, Hon. Mem. S. Afric. Inst. ; Librarian to the London Institution.

CONTENTS OF VOL. XL

NUMBERS LXIV. and LXV.— JULY, 1837.

Page

Mr. Peter Barlow on the Electro-magnetic conducting Power
of Wires of different Qualities and Dimensions, and Inquiry
into the Efficiency of the Galvanometer for determining the
Laws of its Variation 1

Mr. Brooke on the Crystallographical Identity of Phacolite
and the Irish bipyramidal Levyne with Chabasie 12

Rev. J. B. Reade on the Existence of Structure in the Ashes
of Plants, and their Analogy to the Osseous System in Ani-
mals 13

Mr. R. C. Taylor's Notes relating to the Geology of a Portion
of the District of Holguin in the Island of Cuba, and the
Mineral Region on the North-east Coast, from the Observa-
tions of himself and Thomas G. Clemson, Esq 17

Lieuts. W. E. Baker and H. M. Durand on the Fossil Jaw of
a gigantic Quadrumanous Animal allied to the genera Sem-
nopithecus and Cynocephalus 33

The late Dr. Turner's Chemical Examination of the Colour-
ing Matter of the Green-sand Formation 36

Rev. R. Murphy's Remarks on an Error of M. Fourier in his
Analyse des Equations 38

Prof. J. R.Young's Investigation of Formulae for the Summa-
tion of certain Classes of Infinite Series 4-1

Dr. T. Thomson on the Right Rhombic Baryto-Calcite, with
reference to Prof. Johnston's Paper in the Phil. Mag. for May
1837 45

Sir Edw. Ff. Bromhead's Remarks on the present State of
Botanical Classification 48

Mr. Prideaux's Observations on the Deduction of the Dew-
point from the Indications of the Wet-bulb Thermometer,
and on the Detection of minute Quantities of Foreign Mat-
ters diffused in the Atmosphere, with Notices of Apparatus ;
in a Letter to Mr. Brayley 54

Prof. Forbes's Account of "some Experiments made in dif-
ferent Parts of Europe, on Terrestrial Magnetic Intensity,
particularly with reference to the Effect of Height 58

Mr. Beke's Additional Remarks on the former Extent of the
Persian Gulf, and on the Distinction between Babel and
Babylon 6(5

Mr. C. Binks on some of the Phaenomena and Laws of Action
of Voltaic Electricity, and on the Construction of Voltaic
Batteries 68

Proceedings of the Royal Society 89

Geological Society 98

Zoological Society 118

Royal Irish Academy 131

a 2

IV CONTENTS.

Page
Mr. Brayley's Remarks on the Commencement of Sir E. Ff.

Bromhead's Paper on Botanical Classification * . . 137

Mr. J. T. Cooper on the colouring Matter of the Ancient Ruby

Glass 137

Notice of Sir Isaac Newton's Manuscripts 1 38

Analysis of Citric iEther, by M. Malaguti 139

On the Combinations of Ammonia with Anhydrous Salts .... 14?1

On the Oxalhydric Acid of M. Guerin 142

Native Iodide of Mercury 143

Carbomethylate of Barytes 143

Analysis of Gadolinite, by Mr. A. Connell 143

Meteorological Observations made at the Apartments of the
Royal Society by the Assistant Secretary j by Mr. Thomp-
son at the Gardens of the Horticultural Society at Chiswick,

near London; and by Mr. Veall at Boston 144

NUMBER LXVI.— AUGUST.

Dr. A. Fyfe on the Use of Sulphate of Copper for exciting Vol-
taic Electricity, and on the Employment of Iron in the Con-
struction of Batteries 145

Mr. L. Hunton on the definite Combinations of Sugar with the

Alkalies and Metallic Oxides 152

Mons. J. C. Marquart's Report of the Progress of Phyto-
chemistry in the year 1835, in reference to the Physiology of

Plants 156

Prof. Forbes's Account of some Experiments made in dif-
ferent Parts of Europe on Terrestrial Magnetic Intensity,
particularly with reference to the Effect of Height {continued) 166
Mr. Brooke on Murio-carbonate and Native Muriate of Lead 175
Prof. R. Hare on certain Points of Chemical Philosophy and

Nomenclature 176

Proceedings of the Royal Society 189

- Zoological Society 196

Geological Society 201

On the Action of Iodine upon the Vegetable Alkalies, by M.

Pelletier 216

On Hydrobromate of Carbohydrogen (Methylene) 221

On the Preparation of Sulphuret of Carbon 221

Solubility of Oxide of Lead in Water 221

Anhydrous Camphoric Acid, Camphovinic Acid, and Cam-
phoric iEther 221

Gigantic Carp 223

Curtis's Entomology 223

Meteorological Observations 223

NUMBER LXVII.— SEPTEMBER.

Lieut.-Col. Emmett's Experiments made during a Voyage to,
and at Bermuda, on the Carbonic Acid in the Atmosphere 225

CONTENTS. V

Page
Prof. H. W. Dove on the Influence of the Rotation of the
Earth on the Currents of its Atmosphere; being Outlines of

a General Theory of the Winds 227

Mr. S. S. Greatheed's new Method of solving Equations of

partial Differentials 239

Sir Edw. Ff. Bromhead's Memoranda on the Origin of the

Botanical Alliances 247

Prof. Forbes's Account of some Experiments made in different
Parts of Europe, on Terrestrial Magnetic Intensity, particu-
larly with reference to the Effect of Height [continued) 254

Rev. T. Knox on a new Rain Gauge 260

Mr. Brooke on the Crystalline Form of Pyrosmalite : hitherto

undescribed 261

MM. Wartmann and Quetelet's Papers on the alleged Period-
ical Meteors of the 13th of November, and on Shooting

Stars in general 261

Prof. De la Rive's Researches into the Cause of Voltaic

Electricity 274

Mr. W. C. Williamson on the Affinity of some Fossil Scales of
Fish from the Lancashire Coal Measures with those of the

recent Salmonidce 300

Mr. H. M. Noad's Analyses of the Hydrates of Baryta and

Strontia 301

Prof. J. R. Young's Analytical Investigation of Professor Wal-
lace's Property of the Parabola 302

Mr. F. Watkins on Thermo-electricity 304

Proceedings of the Geological Society 307

Carbovinate of Potash 320

Conversion of Iron into Plumbago by Sea-water 321

On a Combination of the Anhydrous Sulphuric and Sulphurous

Acids 321

On Gallic Acid, by M. Robiquet 323

Spontaneous Combustion of Linseed Oil after its becoming dry 324

Process for Ink devoid of free Acid, by Dr. Hare 324

Rapid Congelation of Water by means of Hydric (Sulphuric)
JEther and concentrated Sulphuric Acid, &c, by Dr. Hare 325

Synthesis of Ammonia, by Dr. Hare 326

Rotatory Multiplier, by Dr. Hare 327

Meteorological Observations 327

NUMBER LXVIII.— OCTOBER.

Sir J. F. W. Herschel on the prepared or peculiar Voltaic Con-
dition of Iron 329

Mons. J. C. Marquart's Report on the Progress of Phytoche-
mistry in the Year 1835, in reference to the Physiologv of
Plants '. . . 333

Mr. R. H. Brett on the Bromo-cyanide and Chloro-cyanide of
Potassium and Mercury 340

Mr. Beke on the Complexion of the Ancient Egyptians .... 344

i

VI CONTENTS.

Page

Prof. H. W. Dove on the Influence of the Rotation of the
Earth on the Currents of its Atmosphere; being Outlines of

a general Theory of the Winds {concluded) 353

Prof. Forbes's Account of some Experiments made in different
Parts of Europe, on Terrestrial Magnetic Intensity, particu-
larly with reference to the Effect of Height {concluded) . . . . 363
Dr. J. Keade on a permanent Soap-bubble, illustrating the

Colours of thin Plates 375

Prof. Locke on a large and very sensible Thermoscopic Gal-
vanometer 378

Prof. Meyen's Report of the Progress of Vegetable Physio-
logy during the Year 1836 381

Dr. Dalton's Notice relative to the Theory of the Winds .... 390

Proceedings of the Geological Society 390

. Zoological Society , . 394

British Association for the Advancement

Science: Meeting of 1837, at Liverpool 396

On the Thermo-electric Spark, as obtained from a single Pair

of Metallic Elements, by Mr. Francis Watkins 398

On the Artificial Preparation of Formic Acid 399

Edwardsite, a new Mineral 402

Siliceous and Calcareous Products obtained by means of slow
Actions ; Report by MM. Gay-Lussac and Becquerel, on a

Note of M. Cagniard-Latour 403

New Carburets of Hydrogen : Retinnapthe, Retingle, Retinole,

and Metanaphtalene . . . . 404

Double Salt of Codeia and Morphia 405

Carburets of Hydrogen 405

Ampelic Acid 406

Ampelin 407

Action of Cold Air in maintaining Heat 407

Meteorological Observations 407

NUMBER LXIX.— NOVEMBER.

Prof. Lindley's Remarks upon the Botanical Affinities of
Orobanche 409

Rev. J. B. Reade's further Observations on the Structure of the
Solid Materials found in the Ashes of recent and Fossil
Plants 413

Mr. Lubbock on the Wave- surface in the Theory of Double
Refraction 417

Rev. J. B. Reade on the Chemical Composition of Vegetable
Membrane and Fibre; with a Reply to the Objections of
Professor Henslow and Professor Lindley 421

Dr. Kane on the Powder formed by the Action of Water on
White Precipitate 428

Prof. Meyen's Report of the Progress of Vegetable Physiology
during the Year 1836 {continued) 435

Mr. R. Addams on the Action of Cold Air in maintaining Heat 446

CONTENTS. Vll

Page
M. Wiegmann's Notice of new Discoveries of Ehrenberg re-
specting the Bacillariae 4-4-8

Meteorological Observations taken at Bermuda, in July, August,
anil September, 1836 3 and on September 2lst, 1836, in ac-
cordance with the Suggestions of Sir John Herschel : pre-
pared and communicated by Dr. Dalton 449

Mr. E. Solly on the Palo de Vaca or Cow Tree of South America 452
Mr. W. G. Horner's New Demonstration of an original Propo-
sition in the Theory of Numbers 456

Obituary Notice of Mr. Horner 459

Rev. N. S. Heineken's Description of the Galvanic Shock-
Multiplier :, 460

Mr. J. J. Sylvester's Analytical Development of Fresnel's Op-
tical Theory of Crystals 461

Proceedings of the Zoological Society 469

British Association for the Advancement

of Science: Meeting of 1837, at Liverpool 474

Royal Geological Society of Cornwall. . . . 478

New Books — Bibliographical Bulletin 481

On the Solubility of Arsenious Acid ; by Mr. Taylor, Lecturer

on Chemistry at Guy's Hospital 482

On Stearic iEther and Stearate of Methylene, by M. Lassaigne 487
Meteorological Observations 487

NUMBER LXX.— DECEMBER.

Mr. R. Warington on the Action of Chromic Acid upon Silver,

and its Combinations with the Oxide of that Metal 489

Mr. Lubbock on the Variation of the Arbitrary Constants in
Mechanical Problems 492

Mr. T. Exley's Remarks on M. Mossotti's Theory of Physics,
suggested by Mr. Babbage's Notice of the same 496

Dr. Kane on the Action of Ammonia on the Protochloride and
Peroxide of Mercury 504

Mr. A. Connell on the Nature of Lampic Acid 512

Substance of a Communi«ation on the Temperature of some
Mines in Cornwall and Devonshire, made by R. W. Fox to
the Royal Geological Society of Cornwall, at their last
Annual Meeting 520

Mr. Tovey on an alleged Demonstration of Fresnel relative
to the Wave-surface in the Theory of Double Refraction . . 524

Prof. Meyen's Report of the Progress of Vegetable Physio-
logy during the Year 1836 {continued) 524

Mr. J. J. Sylvester's Analytical Development of Fresnel's Op-
tical Theory of Crystals 537

Prof. Forbes's Letter to Richard Taylor, Esq., one of the
Editors of the Lond. and Edinb. Philosophical Magazine, oc-
casioned by M. Melloni's Paper on the Polarization of Heat,
in the Annates de Chimie for May 1 837 542

Prof. Schcenbein on the peculiar Chemical Inactivity of Bis-

Vlll CONTENTS.

Page

muth, with reference to the Researches of Dr. Andrews ;

and on the Action of Sea-water on Iron, &c 544

New Books: — Mr. Lea's Synopsis of the Family of Naiades :

Bibliographical Bulletin 548

Proceedings of the British Association for the Advancement of

Science, Meeting of 1 837, at Liverpool 551

Gaseous Diffusion 559

Chlorosulphurets of Lead, Copper, Bismuth, and Zinc 560

Polygalic Acid 561

Modified Polygalic Acid 562

Artificial Production of Rubies 563

Theory of Organic Combinations 564?

A new Organic Acid 564*

Sulphonaphthalic Acid 565

Conservation of living Plants during long Voyages 566

Shooting Stars 567

Correction in the Rev. N. S. Heineken's Paper on the Shock-
multiplier 567

Meteorological Observations 567

PLATES.

I. A Plate illustrative of Mr. Brooke's Paper on the Crystallographical
Identity of Phacolite and the Irish bipyramidal Levyne with Cha-
basie ; and of the Rev. J. B. Reade's Paper on Structure in the
Ashes of Plants.

II. A Plate illustrative of the Rev. T. Knox's Paper on his new Rain-
Gauge, and of Mr. W. C. Williamson's Paper on the Affinity of
certain Fossil Scales of Fish to those of the recent Salmonidce.

ERRATA.

P. 447, 1. 9 from the bottom, for " which the air solidifies," read

" which avidity the air satisfies."
P. 460, 1. 5 from the bottom, for H If a wire having a moist sponge

be attached," read " If a wire have a rnoist sponge attached," &c.

(See p. 567.)
P. 492, 1. 4, for " a function of those coefficients," read " a function

of those constants."
P. 516, 1. 16, for " carbonic acid," read "carbonic oxide."

T II U

LONDON and EDINBURGH

PHILOSOPHICAL MAGAZINE

AND

JOURNAL OF SCIENCE.

[THIRD SERIES.]

JULY 1837.

I. On the Electro-magnetic conducting Power of Wires of
different Qualities and Dimensions, and an Inquiry into the
Efficiency of the Galvanometer for determining the Laws of
its Variation. By Peter Barlow, F.R.S., Cor. Mem. List.
France, fyc. tyc*

TN the Bakerian Lecture for 1833f, Mr. Christie has given
A the details of a long and interesting series of experiments
on the magneto-electric conducting power of wires of different
lengths and diameters; from the results of which he infers
that the law of conduction in this case is, that it varies di-
rectly as the square of the diameter, and inversely as the
length of the wire ; and in a subsequent part of the same arti-
cle, by a comparison of the experiments of different authors,
he infers that the same law has place in electro-magnetic con-
duction J, My object in this paper is, to explain the anomalies
that have been observed, and to inquire whether the deflections
produced by the galvanometer ought to be considered as pro-
per measures of the conducting power of the wire without re-
ference to the power of the battery.

It is very desirable that we should be able to reduce the
laws of electro-magnetic action to mathematical principles,
and at a very early stage in the progress of this science I un-

* Communicated by the Author.

t This paper was written in 1834, with an intention of publishing it at
that time j it has however been lying in my drawer ever since, and as the
subject is again brought forward, it may not, perhaps, be uninteresting to
some of the readers of the Philosophical Magazine.

1 [An abstract of Mr. Christie's Bakerian Lecture will be found in Lond.
and Edinb. Phil. Mag. vol. iii. p. 141, and some remarks upon it by Dr.
Ritchie, in vol. iv. p. 208. — Edit.]

Third Series. Vol. 1 1 . No. 64. July 1837. B

2 Mr. Barlow on the Electro-magnetic conducting Poxver

dertook the investigation of several of these laws, such as the
general character and direction of the magnetic force, the law
of its power as depending on the distance and relative position
of the compass and conductor, and on the law as depending
on the length of the conductor immediately acting on the
compass, and some others. My paper on this subject was read
at a meeting of the Royal Society in May 1823, and was af-
terwards published in the second edition of my Essay on Mag-
netic Attractions.

In the experiments above referred to, made with a view of
determining the law as depending on the length of the wire, the
whole length of the conductor remained nearly the same, and
the question was only respecting the change of angle depend-
ing upon the length of that part of the conductor which acted
directly on the needle; but in 1824, in continuation of these
inquiries, I undertook to investigate the laws of the conducting
power, or rather, perhaps, the laws of electro-magnetic inten-
sity, as depending upon the actual length and diameters of
the conducting wires. These experiments were published
early in 1825 in the Edinburgh Philosophical Journal.

It had been ascertained at that time, that a diminution of
deflecting power exhibited itself on the needle by any consi-
derable lengthening of the conducting wire, and my first ob-
ject was, if possible, to determine the law of this diminution,
as also what the law was in wires of different diameters. The
same experiments which I had proposed for this purpose would
likewise, I imagined, determine another important question,
namely, whether the effect was produced by the transmission
of one fluid from the positive to the negative side of the battery;
or whether two fluids rushed simultaneously from each pole ;
or lastly, whether the effect was due to the transmission of
any fluid whatever. My reasoning stood thus : If the effect
is due to a single fluid passing from the positive to the nega-
tive side of the battery, and the diminishing effect, by length-
ening the wire, is due to a dissipation of the fluid in its pro-
gress, a compass placed near the positive pole ought to be
more deflected than one near the negative pole ; or if two
fluids rush simultaneously from both poles, the compasses at
these poles ought to be more strongly deflected than one placed
in the centre, supposing, as I had done, that the diminished
effect was the result of dissipation. I possessed at that time a
powerful galvanic battery, consisting of 20 pairs of zinc and
copper plates, 10 inches square, arranged after the manner of
Dr. Hare's calorimotor ; those of the latter being in connection
with the copper lining of the battery, amounting to 16 square
feet; so that I had about 30 square feet of zinc, and 46 square

of Wires of different Qualities and Dimensions. 3

feet of copper, compressed within a small compass and acting
as single plates.

With this power at my disposal I was anxious if possible
to make the experiments upon such a scale as should leave
nothing doubtful in the results. I accordingly procured about
900 feet of small copper bell wire, in one length. This was
arranged in the manner hereafter described, and experiments
carefully made upon it with three compasses at twenty different
lengths, varying from 838 feet to 98 feet, and the results care-
fully read and registered. The three compasses were placed,
one at each extremity of the wire and the other exactly in the
middle of its length.

Before I proceed to state these results it may be well to
refer to one marked peculiarity in them which is independent
of the laws in question, viz. that with very trifling anomalies
the three compasses placed as above were instantaneously and
equally deflected, proving that the whole wire was in the same
state of electric tension, and that the diminished effect by
lengthening the wire was not, as I had at first supposed, due
to dissipation during its transmission. The same result was
afterwards independently obtained by M. Becquerel and com-
municated to the Royal Academy of Sciences of Paris, and is
now I believe considered as an established law of electro-mag-
netic action.

M. Becquerel also pursued a similar inquiry into the laws
of conduction as depending on the lengths and diameters of
the conductors; and here unfortunately are found discrepancies
between the two results, which it is necessary to examine, par-
ticularly as Professor Cumming seems to have obtained re-
sults in many cases at variance with both.

Confining ourselves at present to that law which relates to
diameter, Professor Cumming in different comparisons found
it to vary from the simple first power of the diameter to nearly
the cube of the same. M. Becquerel finds it to vary as the
square of the diameter ; while in my experiments, beyond very
small limits, I found the deflections wholly independent of the
diameter. Indeed if the deflection depended upon the square
or any power of the diameter, it would follow that we might in
any case supply a deficiency of galvanic power by only enlar-
ging the diameter of our conductor, a doctrine which will not
be maintained ; and yet this is a necessary consequence if we
admit the deflections to be a measure of the conducting power
without limits ; and if it has limits, on what do they depend? —
is it absolute dimension, or has it reference to the intensity of
the battery? This is certainly a question which requires in-
vestigation; for whatever it may be that establishes thes

B 2

4 Mr. Barlow on the Electro-magnetic conducting Power

limits, beyond them the galvanometer must become an ineffi-
cient instrument.

In my experiments I employed twelve copper wires, each
two feet long, varying in weight from 17 grains to 1590 grains,
and twelve brass wires varying from 38 grs. to 3770 grs. ;
the squares of the diameters of course varying in the same
ratio. One would naturally think, therefore, had such a law
had place, it must have been rendered sufficiently obvious in
these experiments ; but so much was it the contrary, that I
could perceive no increase of power in any of the wires which
exceeded in weight 180 grs. for a length of two feet.

These results are therefore so decidedly at variance with
the law above stated, that I shall be excused bestowing a few
lines in describing the manner in which the experiments were
conducted. This was as follows :

Two stout wires about $ of an inch in diameter were bent
into the form shown in the diagram, their ends m m} being bent
down about an inch, properly amalgamated, and inserted into
two wooden cups containing mercury, these cups being about
20 inches apart. Two notches were cut in the sides of the cups
m m\ in which were laid the specimens to be experimented
on, these being placed so that the wire m m' was exactly in the
magnetic meridian, and therefore parallel to the needle placed
between them but considerably below the wire. These speci-
mens it should be observed, were all also bent down an inch at
each end and amalgamated, to be,
like the poles of the battery, in-
serted in the mercury. The notches
in the sides of the cups m m' were
for receiving each successive spe-
cimen, so that no change should
take place throughout in the rela-
tive position of the wire and com-
pass.

The only remaining point to *

guard against was the variable

power of the battery; and to provide against this, a standard
wire, weighing 470 grains, was inserted in the cups, and the
deviation produced by it observed and registered before and
after that produced by each successive specimen ; the mean of
the former deflections was then considered as indicating the
mean power of the battery for that experiment, and it was
thus easy afterwards to reduce all the deflections to those
which would have been produced by a constant power of the
battery.

These observations and reductions are stated in the follow-

[\

of Wires of different Qualities and Dimensions. 5

ing table ; and in the last column I have given the deviations
which ought to have been observed supposing the power of the
wires to vary as the square of the diameters.

Table I.

Weight

of

Specimen.

Deflection
by Standard
before each
Experiment.

Deflection
by Standard
after each
Experi-
ment.

Mean
of the two
preceding
Columns.

Observed
Deflection
of each
Specimen.

Observed
Deflection
reduced to

mean

standard

26°.

Deflections
which ought
to have been

observed if the
power had

varied as L)2.

Copper

Wires.

17

39° 0'

37° 0'

38° 0'

25° 0'

16° 13'

16° 13'

49

35 0

33 0

34 0

31 0

23 29

37 59

59

33 0

31 0

32 0

28 0

22 32

45 17

70

31 0

28 30

29 45

28 0

24 24

50 9

95

28 30

27 30

28 0

26 0

24 6

58 25

140

27 30

26 30

27 0

26 0

25 1

67 20

180

26 30

24 0

25 15

25 30

26 15

72 1

250

22 30

23 0

22 45

23 0

26 16

76 51

290

23 0

21 0

22 0

22 0

26 0

78 36

580

20 0

21 0

20 30

21 0

26 35

83 3

1350

21 0

20 0

20 30

20 0

25 23

87 32

1590

20 0

19 30

19 45
Brass

19 30
Wires.

25 11

87 54

38

33 0

30 0

31 30

26 30

21 38

21 38

44

30 0

29 0

29 30

24 0

20 59

24 40

80

29 0

28 0

28 30

26 0

20 8

37 52

100

28 0

27 0

27 30

23 30

22 9

46 14

150

27 0

26 0

26 30

25 0

24 30

57 27

250

26 0

25 30

25 45

25 30

25 44

69 2

470

25 30

24 0

24 45

24 0

25 13

78 29

(580

24 0

23 30

23 45

23 30

25 44

81 59

1330

23 0

22 0

22 30

22 0

25 26

85 53

1580

22 0

21 0

21 30

22 0

26 34

86 32

1890

21 0

21 0

21 0

22 0

27 10

87 6

3770

21 0

21 0

21 0

21 30

26 35

88 33

With such a series of results, obtained on a large scale,
with a powerful battery, and with every necessary precaution to
ensure their accuracy, it is impossible, using the deflections as
the measure of the conducting power, to arrive at the conclu-
sion, that the power of wires of different diameters and of the
same length varies directly as the squares of their diameters,
or as any power of the diameter whatever.

A similar discrepancy has place in the law which has
reference to the length, M. Becquerel making the power
vary inversely as the length, while my experiments make
it vary in the inverse ratio of the square root of the length,
or at least very nearly in that ratio. I am aware that as-
suming this law, viz. /"* , the errors between the computed

6 Mr. Barlow on the Electro-magnetic conducting Power

and observed variations average about a degree, and in one
case out of twenty exceed two degrees, and for this reason
I have only stated my result as an approximation; but admit-
ting the power to vary inversely as the length, the average error
amounts to nearly 20°, where the whole observed angle does
not amount to 16 ; and on this account I am again obliged to
employ a few lines to explain the manner in which these ex-
periments were conducted in order to trace that error to its
source.

It is not easy to dispose of 838 feet of wire in such a way
that a needle shall not be disturbed by parts of it not intended to
act, and thereby the law of its action become misstated. I had
experienced this difficulty in some preliminary experiments,
which I attempted to make in a room with a much less length
of wire ; it is requisite therefore that I should explain the pre-
cautions taken to avoid this source of inaccuracy. On a grass
plat in my garden I formed a rectangular figure represented
in the diagram by G a V H, driving into the ground strong
stakes at G and H, and at a and b' short square open frames^

10 feet in periphery and 3 feet 6 inches high, (as shown by
abed, a! b' d df,) resembling the square frames or fences used
for young-planted trees. This rectangle was so planted that
G H, a b' were in the true magnetic meridian, and of course
its other two sides at right angles to the same.

The wire being made fast at P, was turned round the prop
G, whence it passed to the frame E, about which it was made
to pass in 37 spiral threads from the bottom upwards; it then
passed from b to «', where it was made to descend in 37 spirals
from above downwards; it then proceeded from d1 to H,
where it was turned round as at G to N. At P and N were
placed the two cups of mercury as described in the last ex-
eriments, which latter were also connected with the battery
, as already explained.

E

of Wires of different Qualities and Dimensions. 7

The lengths of the several parts were P G = \5± feet.

Gc= U£
37 \ turns on frame E =. 375
ba = 28

37| turns on F ... =375

DH = 144

NH = 15£

Total = 838 feet.

The three compasses on which the observations were made
were situated as shown at A, C, D ; the standard compass for
measuring the power of the battery was placed at A, and its
deflection taken prior to each experiment, as described in the
former case, and two separate observations were made on each
length of wire by three observers, one at each compass *.
These observations and those on the standard compass being
made, the battery was raised out of the acid, and the wire short-
ened 40 feet by unwinding two turns from each frame: it was
then again lowered, and similar observations repeated, and
so on, till the length had been reduced from 838 feet to 98 feet.
The compasses and wire were continued at the same distance
at each station, till the wire had been shortened to 398 ; its
action was then so strong that I was enabled after every ob-
servation at the usual distance, to obtain another double ob-
servation with the compass at ]i inch distance; so that from
398 feet to 98 feet I obtained two distinct series, answering
to two different distances. The comparative results were very
nearly the same in both, but for the present comparison I shall
only use the longer series, and state the mean of every two
corresponding observations. Each individual observation may
be seen in the work already quoted.

These mean results and comparisons are given in the fol-
lowing table. The 1st column contains the length of the con-
ductor; the 2nd, the deflection of the standard compass; the
3rd, the mean deflection of the three other compasses; the
4th, these deflections reduced to a constant standard deflec-
tion of 21°; the 5th, the computed deflections assuming the
law to be inversely as the square root of the length ; the 6th,
the errors arising from this assumption; the 7th, the com-
puted deflections, assuming the law to be inversely as the
length ; and the 8th, the errors arising from that assumption.

* It is proper to observe, that at the time I made these experiments,
June 1824, I had attending me for instruction relative to my correcting
plate several of the junior civil officers of the Dockyards, formerly stu-
dents in the Royal Naval College, Portsmouth, to whose assistance I was
much indebted not only in the experiments, but in all the previous ar-
rangements.

8 Mr. Barlow on the Efficiency of the Galvanometer

c

s

Computed deflections and

Computed deflection and

o .

Mean

Deflection

errors, assuming

errors, assuming

OS

.2 8 j

deflection

of

compasses

B, C, D.

reduced to

tan a. »/L = constant *.

tan A. L =

= constant*.

fll

a standard
of 21°.

3

Feet.
838

I

21°

Deductions.

Errors.

Deflections.

Errors.

4° 55

4° 55'

6«» 9'

+ 1 14

4° 29'

-0<>26'

798

24

6 18

5 26

6 18

+ 0 52

4 43

—0 43

758

25

8 12

6 46

6 28

-0 18

4 58

— 1 48

718

25

8 50

7 17

6 39

-0 38

5 15

-2 02

678

26

9 10

7 4

6 50

-0 14

5 33

-1 31

638

25i

10 32

8 31

7 3

— 1 28

5 53

-2 38

598

26

10 20

8 10

7 17

-0 53

6 17

— 1 53

558

26

10 30

8 17

7 32

-0 45

6 43

-1 34

518

29

12 10

8 30

7 49

— 0 41

7 14

-1 1(>

478

30

13 0

8 44

8 8

— 0 36

7 50

— 0 54

438

30

14 10

9 31

8 29

— 1 2

8 32

-0 59

398

301

14 25

9 25

8 54

-0 31

9 23

-0 2

358

3KV

15 10

9 38

9 22

-0 16

10 25

+0 47

318

34

17 0

9 52

9 56

4-0 4

11 41

4-1 49

278

34

17 15

10 1

10 37

+ 0 36

13 19

+ 3 18

238

35

18 20

10 18

11 27

+ 1 9

15 27

+5 9

198

33J

18 55

11 8

12 31

+ 1 23

18 23

+7 15

158

3U

21 25

12 21

13 57

+ 1 36

22 37

4-10 16

118

33t

23 5

13 53

16 3

+2 10

29 9

4-15 16

98

32^

24 40

15 37

17 30

4-1 53

33 52

4-18 15

On examining the errors arising from the assumption that
the deflection varies inversely as the square root of the length,
we find them amount on an average to about a degree, the
maximum exceeding 2° ; and Mr. Christie properly observes,
that with such errors we cannot admit the law of the square
roots. These errors however, employing the law of the in-
verse of the length, would amount to 18°; and it is, therefore,
very desirable to trace the cause of the discrepancy to its
source.

There can be no doubt that M. BecquerePs experiments
were carefully conducted, and the means which I employed are
stated above; there ought therefore to be found some primary
cause for the disagreement, which is, after all, I suspect, not
very remote. In order to lead the way to such an investiga-
tion, I shall offer a few suggestions which have occurred to me,
leaving the bearing they may have on the subject to the consi-
deration of others.

In the first place, I doubt much whether the deflection of a
compass needle, either from the action of a single wire or from

* The constants employed in these computations have been obtained by
finding the value of all the tan A \f L's and taking the mean, and the
value of all the tan A. L's, and taking the mean of these.

for determining the conducting Power of Wires. 9

that of what is called the galvanometer, is any certain measure
of the relative conducting power of a wire, without reference
to the intensity and productive power of the battery employed,
whether our inquiries relate to their length, diameters, or
natural qualities. To take the case of wires of the same kind
and same length, it may perhaps be possible, where the pro-
ductive power is great and the intensity inconsiderable, to em-
ploy a wire so small that it shall not be able to carry off the
whole of the fluid the battery is competent to supply; and when
this is the case a larger wire may be advantageously used, and
if it does not greatly exceed the other, the power of conduc-
tion and the indications of the galvanometer may be consistent;
but after employing a wire capable of conducting away the
fluid as fast as it can be supplied by the battery, it will be use-
less to expect to produce a greater effect on the galvanometer
by employing a greater wire.

Should this view of the subject be correct, it must be ad-
mitted that the indications of the galvanometer are no certain
measures of the conducting power of wires, unless reference
be had also to the intensity and productive power.

To take, by way of illustration, a more tangible, but some-
what analogous case, viz., the conducting power of metals for
caloric. I would suppose a spirit lamp of given power and in-
tensity to have one end of a wire placed in it, and the other
end in a vessel of water with a thermometer; there is, I con-
ceive, in this case no doubt that with small wires the ther-
mometer would indicate their relative conducting powers with
some degree of accuracy, but that it would fail entirely with
very large wires capable of conducting away the heat faster
than it can be generated.

I may also observe that as some metals are known to be
better conductors of electricity than others, it is reasonable to
conclude that a smaller wire of a better conducting metal will
be as effective in carrying off the electricity of a battery as a
larger wire of a worse conductor, and hence, probably, the
discrepancies observed in the results of experiments on the
relative conducting power of different metals. Suppose, for
example, a copper wire to be employed, so small as not to be
able to carry off the supply of the battery, then the same-sized
silver wire will carry off more, and within certain limits the
galvanometer may indicate something like their comparative
powers of conduction; but if larger wires were employed a
different result might be obtained, the justness of the indication
depending, according to this view of the case, upon the cir-
cumstances whether both or either of the wires are larger than
is requisite to conduct away the supply.

Third Series. Vol. 1 1. No. 64. July 1837. C

10 Mr. Barlow on the Efficiency of the Galvanometer

The following table shows the comparative conducting
powers of different metals according to the determination of
Sir Humphry Davy and M. Becquerel, the power of copper
in each being called 100.

Relative conducting power of
different Metals according
to Sir Humphry Davy.

Copper 100

Silver 109

Gold 73

Lead 69

Platinum 18

Iron 14*5

Relative conducting power of
different Metals according to
M. Becquerel.

Copper 100

Silver 73

Gold 93

Lead 8*3

Platinum 16*4

Iron 15-8

The names of these authors are a sufficient guarantee that
each has reported his results correctly, and there must be
therefore some cause for the discrepancies involved in their
estimations which it is very desirable to discover ; for till this
is done we cannot be said to be in possession of any law of
conduction in electricity derived from one source only, and
much less are we enabled to assign the comparative conduc-
ting powers when derived from different sources.

According to the idea I have advanced, the galvanometer
only measures the conducting power of a metal while the wire
is so small as to be insufficient to carry off the generated elec-
tricity ; beyond that point it only measures the intensity of the
battery. Now this intensity certainly varies with the length
of the conductor. Sir Humphry Davy, it appears, considered
the law to be inversely as the length, and M. Becquerel states
this law distinctly ; while the experiments I have referred to
make it nearly inversely as the square roots of the lengths.
So that while M. Becquerel, by quadrupling the length of his
wires, reduced his deflections to about one fourth, mine were
only reduced to about a half, and with nine times the length
to about one third.

My battery, as I have shown, had a large generating sur-
face ; what the other batteries may have been I cannot tell ;
but if, according to the view I have taken, my battery gene-
rated the fluid faster than the conductor could carry it off,
and the others did not, we see at once why the intensity in
my instrument did not exhibit the same reduction ; but if
from the nature and magnitude of these batteries this cannot
be supposed, then this explanation fails and some other must
be sought for.

When we reflect that besides this great discrepancy in the
law of the length, we have a still greater in that which re-

for determining the conducting Power of Wires. 1 1

lates to diameter, and another nearly as large between the
conducting power of different metals as given by various au-
thors, including men of the first rank in the science, we must
conclude that there is some inaccuracy, and that there are pro-
bably other circumstances influencing the results which are not
at present understood. If the explanation I have attempted
should be thought satisfactory I shall feel much gratified ; and
if not, and it should only lead to inquiries that shall elicit a
satisfactory explanation, my object will have been attained.

P.S. My attention during the last three or four years hav-
ing been withdrawn from electro-magnetic experiments, I was
not aware till this paper had been set up that the subject of
these discrepancies had been so fully investigated by M. Lenz,
in an article in Taylor's Scientific Memoirs, Part II. p. 311.
The paper, as I have stated, was written in 1834-, and my at-
tention was only recalled to it by an accidental conversation
with a foreigner, to whom, it would appear, Lenz's Memoir was
equally unknown *.

* [The paper by Lenz here referred to by Mr. Barlow is entitled * On
the Laws of the Conducting Powers of Wires of different Lengths and Diame-
ters for Electricity." In it are successively reviewed the researches and
reasoning on the subject, of Ritchie, Davy, Becquerel, Pouillet, Barlow,
dimming, and Christie; together with a formula derived from the theory
of the galvanic battery by Ohm, which theory, M. Lenz remarks, " being
only published in German, it is unknown both in France and in England."
" This theory," however, he states, " explains perfectly the difference
between Barlow's results and those of other natural philosophers who have
occupied themselves with this subject, as well as the doubts of Ritchie."
After his examination of the results obtained by the physicists above men-
tioned M. Lenz observes, " We perceive, then, by the above, that all the
contradictory results of Barlow's, dimming' s, and Ritchie's experiments, in
opposition to the law established by other philosophers, are reduced to a
mere nothing by an accurate appreciation of the mode in which they per-
formed their experiments ;" and he states that " the axiom that the con-
ductibility of wires of the same substance is inversely as their lengths and di-
rectly as their sections" has been conclusively established by Ohm and
Fechner. He then describes the results which he has himself obtained by
the induced electro-dynamic current, and which are entirely in agreement
with that axiom. The proposition " that in equally good conducting wires
of the same substance the lengths are proportional to the masses, that is to
say, to the sections," appears, it may be added, to have been first demon-
strated by Davy. No. IV. of Scientific Memoirs, to be published this
month, will contain another paper by Lenz, On the laws according to
which the magnet acts on a spiral, and on the influence of the distance of
the convolutions of spirals on the production of the electromotive power
in them. — Edit.]

C2

[ 12 ]

II. On the Crystallographical Identity of Phacolite and
the Irish bipyramidal Levyne with Chabasie. By

H. J. Brooke, Esq., F.R.S., fyc*

[With Figures : Plate I.J

SOME specimens of a mineral in small and nearly transpa-
rent bipyramidal crystals have been received in this
country from Bohemia ticketed " Phacolite," and other speci-
mens in larger crystals of nearly the same form have been sent
from Ireland under the name of " Levyne." It does not appear
by whom these specimens have been so named, but I find on
examination of them that the crystals are alike, and that they
correspond in primary form and angular measurement with
Chabasie ; the common twin crystals however of this substance
consist of only two simple crystals intersecting each other, while
those of Phacolite may be most easily explained by supposing
them to consist of four.

As a more perfect knowledge of these composite forms will
be useful to mineralogy, I am induced to request a place for
the accompanying figures and remarks in the Philosophical
Magazine.

Fig. 1. is a simple crystal of Chabasie, from the combina-
tion of two of which, the fundamental crystal, as it may be
termed, of Phacolite, No. 2, is produced. The planes o
have not been before observed on Chabasie. They result from

the law B of Hairy, the planes n corresponding to 6, r to fe,

and u to t).

Fig. 2. shows the combination of two of these crystals, the
planes o coinciding in surface so as to form one plane in the
twin crystal, and filling up the re-entering angle in the com-
mon twin crystals of Chabasie.

Fig. 3. Two intersecting crystals which are supposed to
cross each other, in the manner represented in the figure,
within the crystals represented by fig. 4.

Fig. 4. The figure of Phacolite, the letters on the several
planes indicating its relation to the preceding figures; with
this difference however, that the planes corresponding to the
P planes of fig. 4 on the actual crystals of Phacolite, are not
single as drawn in the figure, but consist of a number of mi-
nute similar planes, which recede, as it were, behind each
other so as to produce the appearance of rough single planes,
nearly parallel to the planes n on which they rest.

Assuming P on P, fig. 1, to be 94° 46', and denoting the

* Communicated by the Author.

' E&ni. fhiZ.sKz*.£ Jcurn, Vol.12. II I.

The Rev. J. B. Reade on Structure in the Ashes of Pla?its. 1 3
axis by x, the following angles will be found very nearly cor-
rect : x on P = 38° 24/

_ - o = 53 56

n = 57 45

n on o =162 53

H. J. B.

P.S. In No. 61 of this Journal, p. 278, the inclination of
the plane P of Chabasie on the axis is given as 38° 34-' in-
stead of 38° 24?', whence the inclination of P on g is 1 1° 36'
instead of 1 1 ° 26'.

The term doubly oblique prism in Prof. Johnston's paper on
Baryto-calcite, inserted in Phil. Mag. for May, pp. 373, 374,
and 375, should have been oblique rhombic, as correctly given
in line 20 from the bottom of page 375.

III. On the Existence of Structure in the Ashes of Plants
and their Analogy to the Osseous System in Animals. By the
Rev. J. B. Reade, M./i.*
HPHE broad assertion that a plant differs from an animal is
-"■ so obviously true, that while points of difference rapidly
present themselves, it appears to be a matter of no easy ac-
complishment to discover points of resemblance. Man is
not more readily distinguished from other animals by his
divinely bestowed power of looking before and after, than the
generality of animals stand high above all vegetable creation
by their powers of voluntary motion and perception. Yet
there are links in the great chain of organized bodies so al-
most inseparably connected as to compel the naturalist to re-
tire from his examination baffled at the question, Is it a plant,
or is it an animal ? The mere existence of organization is all
that can be detected, and therefore it is impossible to deter-
mine with accuracy, whether the growth and structure of the
individual have been accomplished by the agency of animal
or of vegetable life. But though in some cases the shades
of difference between the products of these two great kingdoms
of nature so melt into each other as almost to lose their di-
stinctness, there are in nearly all cases certain analogies both
of parts and functions, and these not fanciful but real, which
a close examination may detect. And hence it becomes a
task as easy as it is delightful, to trace, in the uniformity of
design and the infinite variety of modification in the execu-
tion, the hand of the Great Master-builder.

Functions of circulation and respiration, as well as func-

* Communicated by the Author.

14f The Rev. J. B. Reade on the Existence of

tions of nutrition and reproduction, are shared in common by
all organized bodies; and it is through the medium of similar
organs that the vital principle carries on these functions, both
in the animal and in the vegetable kingdoms. Accordingly
we find a muscular system in the former, a corresponding cel-
lular system in the latter, and a vascular system in both. In
carrying out these analogies further, it is not uncommon to
find the stem and branches represented as a frame- work or
skeleton for the support of the parts necessary to life. But we
have already included the chief mass of these portions of ve-
getable structure in the vascular and cellular systems; and
surely it would be unphilosophical to make the same parts
subservient to the illustration of different analogies. While,
however, we reject the stem and branches as the skeleton, we
are not driven from the analogy ; for plants as well as animals
have an osseous system ; and it is my design in the present pa-
per to point out its construction and locality.

Having been requested by Mr. R. Rigg, — an able analytical
chemist, whose valuable researches into the composition of
vegetable products will ere long be made public, — to examine
the ashes of plants with the microscope, I procured a platinum
spoon and a large spirit-larnp as my working apparatus.
Portions of plants were then submitted to an intense heat
until the carbonaceous parts were entirely dissipated, and only
a few apparently white ashes remained. The specimens thus
incinerated consisted chiefly of grasses, together with barley,
wheat, &c, and in all of them I have been able to discover,
by means of the microscope, a most beautiful, and in many
a most elaborate, structure. That this detection of structure
in the ashes of plants is altogether new, I must infer from the
silence of our best writers on the subject of physiological
botany. The fact, had it been known, would have appeared
far too interesting and important to be dismissed without spe-
cial notice. The commonly conceived opinion is, to use the
words of Professor Henslow, that carbon fixed under the form
of a nutritive material is elaborated for the development of all
parts of vegetable structure, and that those earthy, saline, and
metallic ingredients which are found in the ashes of plants being
accidentally introduced, cannot with any certainty be looked
upon as products of vegetation, or as ever constituting essen-
tial elements of organization*.

Now, since the presence or absence of organization is direct
evidence of the presence or absence of life, the first thing
which strikes the mind under this newly discovered feature in

* Cabinet Cyclopaedia, Principles of Botany, pp. 176, 177, 224, &c.

Structure in the Ashes of Plants. 15

the ashes of plants is, that combustion does not in this case,
as we have hitherto supposed, supply us with brute matter
merely, but that it leaves behind a purely vegetable product,
a product far from being dissimilar in its nature to the bones
of animals, and having its particles undoubtedly arranged by
the agency of a living principle. Yet I confess that these are
somewhat startling novelties; indeed, so much so, that 1 al-
most shrink from bringing before the naturalist a statement,
which, to say the least, will be at first received with suspicion.
The facts, however, he may easily verify for himself, and I can
only believe that an examination similar to my own will con-
duct him to a similar conclusion.

It is almost superfluous to observe that bones contain, in
addition to animal matter, salts of lime and soda, together
with traces of silica and metallic oxides. The ashes of plants
also, as is equally well known, are composed of earthy, saline,
and metallic ingredients. We have here, therefore, two pro-
ducts, the one animal, and the other vegetable, differing chiefly
in the proportions of similar elements. If it be asked how these
elements are distributed in plants, whether in accidental accu-
mulations or uniformly dispersed throughout their volume, all
we know of creating intelligence urges us to say, that certainly
the dispersion will be uniform, or at least systematic. We
cannot, therefore, be surprised lo learn that such an arrange-
ment is actually detected after combustion, though it may be
gratifying to know that combustion does not disturb so as
to conceal it.

What I wish then more especially to insist upon with re-
spect to the ashes of plants is structure, — the similar conforma-
tion of similar parts, whether those parts be stems, leaves, or
the appendages of flowers and seeds. The variety is evidently
a variety of purpose and plan, compelling us to reject at once
every supposition of the operation of causes without design.
The inability to comprehend the use of this construction is
no argument against the subtlety of the mechanism. The
bare existence of structure is of itself proof sufficient of the
active presence of a living principle, and therefore of a con-
trivance accommodated to some end, and suited to some
office. That end and office, in the present case, may be to
give consistence and support, or there may be some myste-
rious connection even with the healthy existence of the plant.
For did we find the deposition of matter, like silica along
the angles of the Equisetum hyemale, occurring in small masses,
or as lumps, like tabasheer between the joints of the bamboo,
we might with justice suppose, that what seems to be so
casually introduced might be withheld, or if possible removed,

1 6 The Rev. J. B. Reade on Structure in the Ashes of Plants.

without interfering with the process of vegetation. But since
the residual matter which combustion separates is as it were
carefully arranged, in certain definite forms, throughout the
entire plant, those forms varying uniformly in different parts
of the same plant but preserving many similar characters in
similar parts of different plants, we cannot suppose that there is
no connection between structure like this and the general ceco-
nomy of vegetation, or that so concealed but curious a con-
trivance has no share and interest in the functions of vegetable
life.

We may also further infer that there is a chemical union of
the earthy, saline, and metallic ingredients which the ashes of
plants contain. If these ashes were wholly destitute of struc-
ture, we might with justice suppose that they contained their
elements in mechanical combination merely, each particle be-
ing a pure portion of a separate element. But the fact of
organization compels us to conclude that, in each and every
particle of the incombustible residuum, every element is com-
bined under the operation of a natural chemistry. And hence,
under this impression, we can pronounce the ashes of plants
to be a purely vegetable product, equally with the nutritive
products, starch, sugar, and gum.

Whether the physiologist will condemn as fanciful and
vague any idea of analogy between the bones of animals and
this systematic distribution of incombustible matter in plants ;
or whether, — bearing in mind that created things differ in mag-
nitude preeminently, — he will be disposed to confirm such spe-
culations ; these are points which I cannot decide. Of this,
however, I feel confident, that every lover of the microscope
will be glad to place in his cabinet a series of objects which,
to say the least, will call forth his admiration, if they do not
also awaken a suspicion that he is examining structure which
has been obedient to some rule, and is therefore conducive to
some effect.

Peckham, April 27, 1837-

Note. — The above observations may possibly tend to
throw some light on the natural process of the silicification of
wood. By the agency of an intense heat the surrounding si-
liceous matter may be liquefied and the carbon and gaseous
products of the wood dispelled, while the essential characters
of the fibrous and cellular structure are undisturbed. The
unconsumed portions, which alone constitute the true vege-
table frame-work, are then, as it were, mounted in the fluid
silica. This property of retaining its form notwithstanding the
action of heat, which seems to be a characteristic of fibre, sug-

Mr. R. C. Taylor on the Geology of Cuba. 17

gested to me the probability of detecting structure in the ashes
of coal; and, upon examination, I find that the white ashes of
" slaty coal " furnish most beautiful examples of vegetable re-
mains. We have thus additional evidence that the basis of
vegetable structure is independent of carbon.

Explanation of the Figures. (Plate I.)

Figs. 1,2,3. Skeletons of portions of recent plants.

1. Part of husk of Oat, with separate drawings of the cups, which

are attached at nearly uniform intervals along the siliceous
columns.

2. Part of leaf of the Iris.

3. Hair of leaf of Cornus alba (Common Dogwood).

Figs. 4, 5, 6, 7. 8. Siliceous skeletons of portions of plants occurring abun-
dantly in the white ashes of coal.
4,5. Cellular structure.

6. Annular ducts with transverse bars.

7. Spiral fibre.

8. Fibre in situ.

Magnifying power about three hundred linear. The parallel siliceous
lines of the Oat, occurring in some cases at intervals of l-4000dth of an
inch, form a very delicate natural micrometer.

P.S. Since writing this paper, I have been indebted to Mr. Brown's
kindness for the perusal of Struve's Inaugural Dissertation, " De Silicia in
Plantis nonnnllis." It is the author's object to show that pure sillica forms
the skeleton of three species of Equisetum, and also of the Spongia lacustris
and Calamus Rhodan. I am gratified by finding the following remark : " Sub
aeris libero aditu ustis, restat sceleton, totam plantae form am accurate ser-
vans, partibus animalium osseisquam maxime comparandum." p. 12.

My attention has also been directed to Mr. Lyell's observations on
Goppert's Memoir on the Process of Lapidification, Phil. Mag., May 1837,
p. 408, and Ehrenberg's Memoirs on Fossil Infusoria, Scientific Memoirs,
vol. i. part iii.

IV. Notes relative to the Geology of a Portion of the District

of ' Holguin in the Island of Cuba, and the Mineral Region

on the North-east Coast, from the Observations of himself

and Thomas G. Clemson, Esq. By Richard Cowling

Taylor, Esq., F.G.S., fyc.*

W/*E have prepared a detailed description of the mineral

** region in the vicinity of Gibara, and particularly as to

its copper lodes ; but as some delay will unavoidably take

place in its publication, I have arranged a portion of our

notes as a preliminary communication to the Philosophical

Magazine.

A considerable portion of the year 1836 was devoted to an
examination of the north-east part of this island, a mineral
region which, so far as I can learn, has never been visited for
scientific purposes, and till recently has never been investigated
for the practical objects of mining.

* Communicated by the Author.
Third Series. Vol. 11. No. 04. July 1837. D

18 Mr. R. C. Taylor's Notes relative to the Geology of Cuba,

The area of which I propose now to give a sketch is si-
tuated between the city of Holguin and the sea, and forms a
mountainous belt or zone parallel with the northern coast of
Cuba. That part of it, at least that part which is within the
limits of this investigation, in which copper lodes of value have
been proved, appears to be only two or three miles in breadth.
The centre of this mineral range is about eight miles, in a
straight line from the Embarcadero or landing-place of the
Gibara river; from hence that stream is navigable for lighters
four or five miles to the bay and port of Gibara. The known
copper lodes are almost entirely limited to the Savanas, which
it may probably be not uninteresting first to describe.

Natural Features of the Savanas. — This term, in the island
of Cuba, implies an elevated hilly range, for the most part
clear of wood, excepting the Corojo palms, the Palmettos
of two or three species, and some occasional patches of low
thorny bushes, aloes, and beautifully flowering shrubs, peculiar
to these sites. The surface is everywhere thickly strewed with
detritus of the prevailing serpentine rocks of the district, and
is covered with a coarse description of grass, rejected by cattle,
and which is commonly fired in every spring, either for the
improvement of the scanty pasturage, or from time to time, to
facilitate the search after copper veins.

Innumerable small streams and ravines, whose beds are dry
during the greater part of the year, wind amidst the Savanas
in the most intricate manner ; descending to larger streams on
their way to the main outlet at the bay of Gibara, or to that
of Barriay and others which indent the north-eastern coast of
Cuba. Their courses in the elevated country are distinguish-
able by the superior luxuriance of the vegetation along their
banks. These streams, with their borders of rich and wood-
land soil, form the boundaries of the numerous distinct Sa-
vanas, each of which bears its separate name.

Smaller detached areas of open and unimproved land, re-
sembling the Savanas, appear on the hills which rise from the
midst of the surrounding woods. They are known by the
denomination of Saos, and are kept open by occasionally firing
the coarse herbage. The rocks which appear on their sur-
faces are of the same character as thosj on the Savanas, and
sometimes indicate mineral traces.

Still smaller open and elevated areas are called Saoitos, and
partake of the common character, having a few straggling
palmettos and mahogany trees dispersed over their rocky sur-
faces.

The Savana region, whose extreme limits are imperfectly
defined, and of which but a comparatively small portion has

from the Observations of himself and Mr. Clemson. 19

at present been ascertained to contain veins of copper, is re-
markable for the undulations of its surface, and consists of a
countless series of rounded hills, which rise from one hun-
dred to four or five hundred feet above the bed of the prin-
cipal streams. Some of these hills are prolonged in the form
of ridges, stretching several miles in a direction varying be-
tween north-east and east ; their sides penetrated deeply, at
inconsiderable intervals, by innumerable lateral ravines.
Other eminences are so surrounded by watercourses and ra-
vines as to appear in regular oval or circular forms, as if con-
structed by the hand of man, like the ancient mounds and
earth-works of Europe, on a gigantic scale. Some of them
are a few hundred yards only in diameter, and rise from two
to four hundred feet in elevation, and slope on all sides with
a remarkable uniformity. To speak of these conformations
of the surface, chiefly derived from the slow operation of
drainage, as mere undulations will scarcely convey an adequate
impression of the superficial character of this region. It is
seldom that so extensive an expanse of country is seen, which,
without presenting any precipitous faces of naked rock, main-
tains over its entire area a surface so uneven. Standing upon
one of these eminences in the midst of the savanas, and looking
over those countless barren and rounded hills, the only scene
to which they may be compared, yet on a very inferior scale
as to magnitude, will be the billows of an agitated ocean.

These circumstances of external configuration are not un-
important to the miner, who will perceive the facilities they
offer to his operations, and how readily these ridges and hills,
containing the mineral veins, can be reached, and worked,
and drained, to a great depth, from the adjacent ravines.

White Limestone Mountains. — Whilst describing the pecu-
liar features which characterize this part of the island, and
which are mainly attributable to geological phenomena, we
may not pass unnoticed those remarkable mountains of lime-
stone or marble, which not only approach the borders of the
savanas, but even rise in the midst of them.

As we approach the bay of Gibara from the sea, the aspect
of the coast and country inland is bold and striking. Moun-
tains of strange forms, pinnacles and isolated bluffs, and ele-
vated saddle-shaped masses, steep and bare of vegetation on
their faces, range along the coast at the distance of a few miles
in the interior.

We cross them, and amidst them, and pass to the savanas
in their rear, towards the south. From hence, as they stretch,
at intervals, to the east and to the west, a scene unusually
striking and geologically interesting presents itself.

D2

20 Mr. R. C. Taylor's Notes relative to the Geology of Cuba,

From the midst of the barren savanas and the lower wooded
plains arise those lofty detached mountains of compact marble,
whose singular forms, and whose white, precipitous, waterworn
sides, contrast so remarkably with the rounded, sunburnt hills
of the savanas, and give such a peculiarity to the contour
of this coast, and furnish to the mariner such conspicuous
landmarks. At a little distance, and even at several miles
from the base of these mountains, their precipitous faces ap-
pear vertically and distinctly striated, like clusters of enormous
columns, hundreds of feet in height. We at first attributed
this appearance to the possibility of a section of vertical strata
being thus presented. But on closer examination we found
no such traces of stratification : all sides appeared to possess
the same singular, strongly marked vertical lines; and we saw
that this remarkable columnar appearance was derived from
the erosion of the perpendicular lace of the hard rock, wher-
ever exposed to the atmosphere, into deep vertical grooves or
flutings, on a large scale.

On the mountain of La Silla this phenomenon is beautifully
exhibited ; and when from its summit we looked down upon
the numerous spurs of this mountain, and upon its surround-
ing masses, we had the singular prospect of apparently an
immense assemblage of groups of enormous crystals of white
rock, distributed over a space more than a mile broad and two
or three miles long, shooting perpendicularly upwards from
the woods below, and contrasting strongly with the dark green
foliage of a tropical forest.

From the bases of the Toro loco, the Llavason, and the
Siera alte mountains, particularly the former, an equally grand
and singular view is presented, resembling snow-white basal-
tic pillars, clear of all vegetation on their sides, except here
and there an aloe rooted in some crevice. At this distance
the illusion was equally beautiful; when looking to the ir-
regular outline of their crests, it seemed as if the entire moun-
tains, a thousand feet in height, formed one enormous group
of vast crystals.

Intermediate Valleys and Plains of rich Alluvial Soil. — In
close contiguity to, and intermixed with many of the savanas,
are extensive tracts of low and comparatively level alluvial
land, the richest, the most luxuriant, and the most prolific, per-
haps, in the world. A very small portion of this land is other-
wise than in its primitive state of nature, and is covered with
timber of the most valuable properties. When cleared, its fer-
tility is apparently inexhaustible, requiring no manure, and it
is capable of yielding two or three crops in one year.

This singular intermixture, this close approximation of ab-

from the Observations of himself and Mr. Clemson. 21

solute barrenness and redundant fertility, is not the least strik-
ing among the peculiarities of the region under consideration.
We have chosen here to advert to it, because it cannot fail to
be seen from this circumstance, that in an ceconomical point of
view it bears materially upon the convenience, and conse-
quently upon the local value, of sites hereafter designed to be
scenes of a busy population connected with the mines, which
though seated within an area of positive sterility will derive
incalculable benefits from their proximity to one of the utmost
fecundity.

flocks of the Savanas. — Our notice of the rocks and nature
of the ores of this region will be brief, and will be reserved
in detail for another place. The rocks of the mineral district
may be divided into two classes: those which contain much
diallage and are more or less crystalline in their structure;
and those in which that mineral is wanting or is less prevalent;
and they all may be arranged under the head of serpentine
rocks.

They are sometimes distinct, and, again, are mixed in all
proportions. The surface rock, as well as that which has
been extracted from the shafts and levels but which has been
exposed for a while, is more or less in a disintegrated form ;
of a soft unctuous touch, and easily reduced to powder. As
the constituents of this rock happen to vary, it changes into
one of a petrosiliceous nature, is hard, and resists the disin-
tegrating nature of the atmospheric agents. We have pre-
viously made mention of this class of rocks in our account of the
bituminous veins within them, in the vicinity of the Havana*.

Copper Ores. — The surface ore, or the mineral substance
containing copper, that is found at the outcrops, or upon the
back of the veins within a few feet of the surface of the ground,
differs materially in its physical characters and in its chemical
composition from that ore which is found to predominate in
the same lode at greater depths. The term surface ore is here
applied to amorphous or informal masses of mineral, of dif-
ferent colours, containing more or less metallic matter.

Frequently at the outcrop of veins containing cupriferous
ores, the term surface ore is applied to a heterogeneous mix-
ture of several distinct mineral species, of which copper forms
one of the constituents, associated with other minerals of little
or no value. These ores are generally red, brown, black,
green, and the different hues that grow out of an indiscri-
minate mixture of those colours ; the most prominent of these
species being the oxides, sulphurets, silicates, and caibonates
of copper, with iron, &c. As we descend upon the vein the

* Set Loud, and Edinb. Phil. Mag., vol. x. p. 161.— Edit.

22 Mr. R. C. Taylor's Notes relative to the Geology of Cuba,

ore assumes a different character. The copper is then found
in combination with sulphur and more or less iron ; the
mineral having a foliated structure, which it owes to an inti-
mate mixture with the foliated magnesian rock, its gangue.
At the depth of ninety feet, as we observed in the Buena
Isabela mine, that structure is lost, and a more compact and
permanent form is assumed. Occasionally the foliated cha-
racter is maintained, but it is not so marked as nearer the sur-
face*. This ore is raised from the depth quoted in masses
of from fifty to three hundred pounds weight each, and free
from gangue ; but masses have been detached, by blasting, of
the estimated weight of one thousand pounds.

Native copper is met with, particularly at the mine of San
Fernando, on the upper portion of the lodes, and descending
to the depth of thirty yards. This occurs in masses of from
ten to two hundred or more pounds weight.

Chromate of Iron of great purity occurs in beds and irre-
gular veins in the serpentine rocks at several places in this
district. At one point masses containing many cubical yards
project several feet above the general surface of the savana.

Discovery and Progress of the Mines in the Savana Region. —
It does not appear that any knowledge of the actual existence
of lodes of copper on the north-east side of the island of Cuba
prevailed before the year 1830. Soon after this time, how-
ever, a couple of Mexican working miners were employed to
explore for gold amongst the hills and open savanas within
the district of Holguin. It was during their ineffectual re-
searches for the more precious metal in this quarter that the
first copper veins were discovered; and subsequently the de-
nouncement of San Fernando, containing three veins, was
commenced, and entrusted to the management of a Mexican
manager, by John Bedopia, Esq., an English resident on the
island. We have taken the liberty of mentioning this gentle-
man personally, because to his individual enterprise we are
in a great measure indebted for determining the existence of
mineral veins within this district.

The mine of San Fernando has continued to be worked by
negro labour, although but slowly, and under all the disad-
vantages of the old Mexican system and incompetent manage-
ment. The ore is a sulphuret, of a bronze green colour,
rich in copper, and intermixed with rich gray ore, and, to the
depth of the first 30 yards, with native copper.

In the same vicinity have been subsequently made by the
same proprietors the denouncements of Socorro, San Antonio,
San Juan, Miua Inocentes and San Olivo,
» T. G. C.

from the Observations of himself and Mr. Clemson, ^3

In the mean while, during the active search for gold by
numerous individuals, discovery was made of the vein de-
nounced under the appellation of San Augustin, and which
now comprises the four veins of Prosperidad, Santa Isabel,
San Augustin, and San Nicolas, The ore of San Augustin is as
rich as any in the district, so far as has been examined, vary-
ing from 23*30 to 51*60 per cent.

The denouncements of La Buena Isabela and Perseverancia
commenced being mined in 1834. A few English miners
were employed in the former in the year 1835, and after prov-
ing the vein, the works were suspended on account of some
temporary difficulties on the part of the owners.

Stimulated by the success which attended the mining of the
Cobre veins in the vicinity of St. Iago de Cuba, the researches
on the north side of the island were continued on a limited scale
by a few individuals. During the last two or three years,
notwithstanding no mining undertaking had been conducted
so far as to bring in a single dollar, great activity was exhi-
bited in searching all the savanas through a great range of
country. These explorations, however eagerly prosecuted,
have up to the present moment led to no other new de-
nouncement than that of Savana Veija. Indications and traces
have been observed at detached positions, but among these
no works, except of the most trivial and superficial nature,
have been proceeded with.

All the denouncements made up to the time we are now
writing are comprised within an area of only five miles in
length by two in breadth. That of Savana Veija is among
the most promising. The principal vein was discovered in
1835, but copper had been traced at one or two points on
this savana three or four years earlier. There appear to be
seven or eight good veins here, which are imperfectly proved.
No capital has hitherto been employed in this undertaking ;
and in fact this may be said of the entire region, with the ex-
ception of the San Fernando and the Good Isabella mines,
and even in them it has been expended to a limited extent only.

Assays of the ores from the various denouncements within
this region have been made in abundance, with a view to the
ascertainment of their quality. These results, however satis-
factory, it is scarcely necessary to communicate in detail here.

White Limestone of Holguin District, — I add a few addi-
tional notes relative to this rock.

Having examined numerous mountains, hills, and belts of
this beautiful rock, and traced their connection with the ad-
jacent formations, we were led to the opinion that it is of the
same geological age as the serpentines, the greenstones, the

24- Mr. R. C. Taylor's Notes relative to the Geology of Cuba,

diorites, and the euphotides which occupy so large an area
in the island of Cuba.

In the vicinity ofSavafia Veija are limestone hills, composed
of very thin layers or laminae, dipping to the south from 50°
to 75°. This rock is white, occasionally tinged with green,
and contains numerous interposed beds, varying from half an
inch to 4 inches thickness, of red and flesh-coloured crystal-
line limestone. In other situations we observed that this lime-
stone is either cream-coloured, or with various delicate tints
of yellow, green, or pink.

The Gibara river is crossed repeatedly by bands of this
limestone, which are traversed by a network of quartz veins.
In these positions the rock exhibits evidence of having been
shattered and broken, the fragments being reunited in a sili-
ceous cement, and so distorted that the original arrangement
of the laminae or seams of the limestone is obscure and almost
obliterated. In general all these traces of original stratifica-
tion are absent, which inclines us to the opinion that we see
the mass only in a modified form, and that it has been sub-
jected to the same influence which has changed the adjacent
rocks, and modified the quartz into a substance resembling
porcelain, and converted the serpentine almost into a vitreous
slag.

We examined two small conical hills of unstratified white
limestone near the Sao Gibara, which seem to be surrounded
by greenstone. We may mention here that we have observed
greenstone at the base of most of these limestone mountains;
among others in that of La Silla, where the greenstone
seemed confounded or intermixed with the limestone. We
shall advert to this further on, as a fair illustration of a class
of mountains which characterizes so strongly the eastern parts
of Cuba. The summits of these and other hills of similar
character are broken into large masses, and exhibit extensive
fissures, affording hiding-places to the numerous wild dogs
which infest the country.

The structure of this beautiful marble is extremely fine and
compact, too much so, I am informed, to admit of its adapta-
tion to external building purposes, as I had anticipated ; but
for finished and more delicate work in the interior, and for
the ornamental departments of architecture and sculpture, it
appears well adapted. Its fracture is conchoidal ; its colour
commonly white or cream-colour, or slightly tinted, and its
texture inclined to waxey. The specific gravity is great.
Blocks of almost any magnitude may be obtained without a
flaw. When struck with a hammer the loose fragments emit
a sonorous ringing sound. Upon the mountains all the ex-

from the Observations of himself and Mr. Clemson. 25

posed surfaces are honeycombed and have sharp projecting
points as in the coral rock of the coast.

Upon the skirts of most of these mountains are tufaceous
deposits, covering the surface; which calcareous tufa has been
derived from the decomposition of the rock, and is brought
down by the numerous springs which descend the hills. This
soft tufa incloses various extraneous substances, and contains
beautiful impressions of leaves and vegetables.

Organic Remains, — In this rock traces of organic remains
are so extremely rare, that during months of examination but
two or three specimens came under our observation. They
were madrepores, the structure of which had been partly ob-
scured by crystallization, or by the change which the mass of
limestone had undergone. We have not observed the slightest
trace of a shell in this formation. It is possible that it may
have originally contained organized fossils which have been
obliterated by the modification to which the rock has evidently
been exposed. No mineral veins or substances were detected
in it.

From the foregoing description it would appear that this
rock or marble is neither the white limestone with tertiary
shells, described by Mr. De la Beche as abounding in Jamaica ;
nor the compact lithographic limestone, sometimes containing
Pectens, Cardites, Terebratulae, and madrepores, described
by M. de Humboldt at the west end of the island of Cuba,
under the name of Calcaire [Jurassique?] de Gui?ies, which
we ourselves have had some opportunity of examining in the
vicinity of Havana. We conceive that it is more ancient than
those rocks ; and that it is contemporary with the Euphotides
and metalliferous serpentines of this region.

It is a prevailing character of the Holguin and Gibara lime-
stone that it contains large masses of carbonate of lime of a
much later origin. These are accounted for, on the supposi-
tion that they were open fissures, cavities, and even large ca-
verns, which in process of time have been wholly filled by
stalagmitical infiltration. All these later deposits are of a
brick-red colour, remarkably fetid, and embrace vast quan-
tities of casts of land shells, occasionally intermixed with ma-
rine univalves, and with a few small bones, apparently of the
great Indian rat, one of the very few indigenous quadrupeds
of the island, and now inhabiting the same mountains.

LaSilla. — This singularly-shaped mountain of white lime-
stone is about two miles long and one in breadth. Its sides,
towards the summit, are bare and perpendicular, so that only
at one or two points is it practicable to attain the top, by the

Third Scries, Vol. 11. No. 61. July 1837. E

26 Mr. R. C. Taylor's Notes relatme to the Geology of Cuba,

assistance of the luxuriant foliage of certain creeping shrubs, or
an occasional tree growing amongst the recesses and crevices.

The barometer being injured in the ascent, no correct cal-
culation was made of the height of La Silla, which we esti-
mated at from one thousand to twelve hundred feet above the
sea, here distant about eight miles.

Contrary to our expectation, we found that the summit was
limited to a narrow ridge ; a mere vertical wall of honey-
combed limestone, on which it was practicable only in a few
places to obtain sufficient space for standing, assisted by the
shrubs that were rooted in the crevices.

We have adverted to the singularly beautiful appearance
of these rocks when viewed either from the crest or from below ;
which effect was produced by the vertical wearing or erosion
of the white marble in grooves, giving them the aspect of
enormous columns and of gigantic groups of crystals.

The upper surfaces of this rock are deeply honeycombed ;
that is to say, they have numerous sharp projecting points, on
which it is dangerous to walk, and have also innumerable cir-
cular holes two or three inches in depth and one inch or more
in diameter, perfectly smooth and regular in their interior, as
if bored with an auger.

No stratification can be perceived in this enormous mass of
limestone. Certain lines of separation there are, which may
be traced at various angles, as well as vertical fissures, but
none of these were the result of stratification. Large blocks
are commonly seen piled on the sides near the summits of
these mountains. They are remarkably sonorous when struck,
ringing under the blow of the hammer like a bell.

Land-shell Limestone of La Silla. — We have adverted to
the barrenness of the white marble in organic remains, and
we obtained from hence only a single specimen, a madrepore,
which was somewhat modified in form.

We have now to describe a deposit, rich in fossil shells, of
a novel and remarkable character.

On the surface and on the sides of La Silla is a great abund-
ance of subsided masses of stalagmitical rock, derived from the
limestone, and filled with hollow casts of an immense assem-
blage of univalve shells, which at the first glance I thought
were tertiary. On examination these shells were observed to
be peculiar to a separate rock of a brick-red colour, but the
position of that rock was not immediately discovered. This
red earthy stone was also crowded with small spherical bodies ;
black, smooth, polished, with minute rounded and kidney-
shaped pebbles, from the size of mustard-seed to that of a

from the Observations of himself and Mr. Clemson. ?7

small pea. They were unequally distributed, and in some spe-
cimens but few can be observed. The shells were in almost
every instance enveloped in crystallized carbonate of lime.

During subsequent researches we ascertained that the red
rock was not interstratified with the white limestone, but oc-
cupied the spaces formed by ancient open fissures, sometimes
a few inches only in thickness; but in one instance, within fif-
teen feet only of the summit, it was exhibited of the breadth
of fifty feet, and of a thickness varying from ten to thirty.
This mass was evidently composed of a numerous series of
<leposits, having different tints, and being more or less earthy
or crystallized, emitting an offensive odour when broken.

It was not until after two or three visits to this mountain
that we traced satisfactorily the extent of these insulated shelly
deposits, acquired a knowledge of their origin, and per-
ceived the process by which they were consolidated. It be-
came evident, on comparison, that these univalves, which were
as abundant as in any deposit we have seen, were referrible to
land genera, such as exist in profusion among the rocks of the
same mountain, amounting to eight or nine species at least.
The inhabitants of these shells retire into the open fissures
and caves, and in some instances are probably carried into
them ; and the dead and unoccupied shells lie in vast num-
bers in such places, in every instance mixed with the red
earth, similar in colour to the more earthy portion of the con-
solidated rock. These caves are resorted to by multitudes of
bats, and beneath the holes in the roof where they most con-
gregated I observed heaps of the dung of these animals, of a
bright red colour, as if derived from some seeds or berries
upon which they had fed. It is possible that a portion of this
red colour of the earth and of the consolidated rock was de-
rived from this source, and probably the globular bodies to
which I have referred originated in the same way.

By the stalagmitical process the shells, together with other
extraneous substances within its influence, become enveloped
in crystallized carbonate of lime, and the operation of infiltra-
tion may be seen slowly but uniformly proceeding, until caves
and fissures of considerable size are wholly filled up with the
new mass, and are consolidated with the older limestone.
Sometimes the mass contains brecciated fragments of this white
limestone. It approaches in colour to the osseous breccia of
Gibraltar. We had little hope of discovering bones of large
animals in the caves of an island which contained on its dis-
covery no quadruped larger than the Indian rat. But we
met with fragments of bones which we referred to the Hutia,
or large Indian rat of the island, which is nearly the size of

E2

28 Mr. R. C. Taylor's Notes relative to the Geology of Cuba,

the raccoon. The Hutia is the largest if not the only native
quadruped of Cuba, and we observed it on the very spot
where we conceived we had recognised its fossil remains. Its
flesh is sought by the negroes as a favourite food.

On first consideration it appeared almost incredible that
land shells should accumulate in such multitudes as we find
them, packed together in layers irregularly within the red
stalagmitical limestone. But having witnessed in the caves of
La Silla the myriads of dead shells there assembled and lying
in heaps upon the floor of red earth, we perceived that the
process was then going on before our eyes, and that by the
infiltration and crystallization of carbonate of lime, these shells
were entombed, consolidated, and the whole mass converted
to a beautiful marble. This process continues until some of
the caves are completely filled up, and the recent mass be-
comes an integral part of the original rock.

In the interior chambers of the caves, which were the
furthest removed from light, the only living shell I observed
was a Clausillia, which adhered to the walls in great num-
bers.

I may observe that no traces of the original shells were no-
ticed in the newly-formed rock ; the matter of the shell seems
to be absorbed during the change it undergoes, and its con-
version to solid rock.

There yet remains an interesting fact to be pointed out.
Amongst the numerous land-shells which the red shelly mo-
dern rock exhibits may be detected, occasionally a univalve
which is decidedly marine, and the same circumstance is ob-
servable among the dead land-shells in the caves. It was this
occurrence of marine shells that occasioned our hesitation, and
prevented us from earlier deciding on the real origin and cha-
racter of the new red shelly limestone. We perceived that
perfectly fresh or recent marine univalves were by no means
uncommon even upon the highest crest of the mountain of
La Silla. This mystery was solved when we found that the
active agents in the transportation, and in the admixture of
sea and land exuviae, were the soldier crabs, which abound
here, and which inhabit the littoral shells almost wholly,
wherever they are found, borrowing those habitations for their
temporary purposes, and discarding them when too small for
their convenience.

The soldier crabs (genus Pagurus) at certain seasons re-
sort to the sea-shore, where we have seen them in great quan-
tities. They return from their pilgrimage, carrying or rather
dragging the shell of some marine univalve for many a
weary mile; and thus, like the pilgrims of the olden time, each

from the Observations of himself and Mr. Clemson. 29

bearing his shell to denote the character and extent of his
wanderings, they proceed for miles into the interior. Thus,
at the distance of eight or ten miles from the nearest shore,
we trace them to the very summit of a precipitous mountain,
almost twelve hundred feet high. When these borrowed ha-
bitations become too confined for the accommodation of their
tenants, the crabs desert them, and seek for larger shells,
leaving the others mingled with the terrestrial shells, as we
observed. The marine shells which had been thus convey ed
from the sea to the top of La Silla were
Trochus, two or three species.

Turbo, two or three species, particularly T. muricatus, Lam.
Littorina, one.
Monodonta, one.
No doubt other genera and species were also transported
thither by the same agents, but those above mentioned we can
testify to.

Of the land shells, which exist equally in a fossil state on
the mountain of La Silla, and were seen abundantly in their
living state in the same locality, we have collected the follow-
ing, of which Mr. Isaac Lea has kindly furnished us with the
specific names.

Cyclostoma sulcata, var Lamarck.

Itupa mumia Lam.

Carocolla marginata Lam.

Carocolla ?

Helix microstoma Lam.

Helicogena auricoma

Helix muscarum Lea.

Helix purpuragula ? Lea.

Clausilia ?

Caves of La Silla. — At about a hundred and fifty feet below
the summit of the mountain of this name is an extensive suite
of caves. Those we passed through, six in number, extended
above three hundred feet to the south, and others stretch oft"
to the north, in the compact white limestone to which we have
referred. These caves swarmed with bats, snails, spiders,
tarantulas, scorpions, and other vermin, and the large snake
called the Majus. They are also the resort of hogs, which run
wild in the woods, and bring hither a well-known pest in the
insect termed the Jigger.

The entrance to the cave is at the bottom of a perpendicu<-
lar cliff of limestone. The interior is not unlike to an Anglo-
Norman crypt, having a heavy groined roof and 'pillars of
continually increasing stalactite. This tendency to encrust
the walls or sides contracts the areas of the chambers, to some

30 Mr. R. C. Taylor's Notes relative to the Geology of Cuba ,

of which the apertures are nearly closed up. All these cham-
bers have nearly level floors, covered to an unknown thickness
with red earth or mould, on which is thickly strewed the dung
of the thousands of bats which congregate here, and myriads of
snail-shells. I think the dung of the bats alone would be in
sufficient quantity to account for the red earth, and that the
colouring matter of this earth and of the rock into which it
passes is vegetable and not mineral, as the examinations to
which it has been submitted appear to determine. We would
have ascertained the depth of this soil on the floor of the cave,
but the annoyances from the causes alluded to rendered our
stay there almost impracticable. We ascertained quite enough,
however, to feel assured that in this soil, to which the bats
have largely contributed and have coloured by some vegetable
exuviae, — in the multitude of dead and decomposing shells, for
which this cave seemed the charnel-house, the tomb of mil-
lions,— in the gradual conversion of this mass to the state of
solid rock, we saw the origin of those beds of shelly carbonate
of lime which at first sight seemed almost inexplicable.

Admixture of Terrestrial, Marine, and Freshwater Shells, —
The shores of the bay of Gibara supply to the geologist an
instructive instance of this association of shells of different
habits. There are several streams which empty themselves
into this bay, and which in times of floods, during the rainy
season, bring down an immense number of dead land-shells
from the high lands of the interior. We here noticed ex-
tensive banks -or deposits of terrestrial and marine shells,
as on the mountain of La Silla; but the agency is re-
versed. In the one case we saw that the marine shells were
conveyed by those active agents the soldier crabs even to
the highest crest of La Silla. In the other the land shells
have been brought down from the rocky recesses of La Silla,
and are deposited in multitudes with those of the sea, on the
margin of the estuary. Were any great geological catastrophe
to occur, by which these accumulations would be buried, and
be subjected to the examination in future times of some in-
quiring naturalist, he would see repeated here the phenomena
which have been observed in more than one position in re-
mote parts of the globe : with these he would find also a full
proportion of freshwater shells, but of one genus and species
only, the inhabitants of the Cuba streams, the Neritina vir-
ginea of Lamarck ; of which great quantities are brought down
by the freshes and deposited on the beach with the terrestrial
and sea shells, and with the small oysters which cluster so
thickly on the pendent branches of the mangroves of the
creeks.

from the Observations of himself and Mr. Clemson. 31

Coral Rock of different Ages on the Shores of the Island of
Cuba. — In our examination of the rocks which approach the
north coast of Cuba, we have seen nothing to countenance the
hypothesis of a gradual transition from the crystalline white
limestone we have described in this article, to the fragmentary
coral rocks which appear on some parts of the coast, and
thence to the modern reef of living corals which encompasses
the Indian islands. Some such passage we have observed on
the borders of the sea near Matansas, the Havana, and the
Moro Castle; but the compact limestone of the first class is
not in those positions, and a newer lithographic rock inter-
poses.

On the west side of the Bay of Gibara the white limestone
is observed, declining at first at an angle of 45°, and then de-
creasing to 20° towards the sea. Upon and near the base of
this slope rest ancient beds of aggregate coral rock, reaching
to about twenty feet above the present high-water line. This
rock is indurated and externally honeycombed like the white
compact limestone of the mountains.

Three or four miles to the west of the bay the shore is
bordered with a reef of living corals, having an intermediate
space of shoal water called the Baxo, nearly half a mile broad,
between it and the beach. This shoal has been described in
detail by Mr. II. C. Taylor in Loudon's Mag. of Nat. Hist,
vol. ix. p. 449, &c.

High up on the beach may be seen a more ancient reef,
forming a solid ledge of aggregate rock, for the most part
composed of corals, shells, and coral sand or mud, now conso-
lidated into a hard rock or cliff, some twenty or thirty feet
high, against which the surf beats violently at high water.
This is another proof of a change of level on this coast. The
old reef, of which we spoke, after continuing for a mile or two
as a cliff whose base is washed by the waves, passes obliquely
inland, and now has a hill covered with a thick wood of wild
fig, sea-grape, and a few aloes and palmettos between it and
the sea. This rock is also honeycombed, its surface being
full of holes and sharp points. In the mass, which consists of
various madrepores and cabbage-formed corals of great size,
we observed spines of Echini, and numerous univalve and bi-
valve shells, having their cavities wholly filled with indurated
coral, sand, or mud ; the whole forming a perfect illustration
of the consolidation of an old rock containing organic remains,
some of the oolites, for instance, the coral rag, or the Farring-
don coral beds.

From this old reef we collected a series of characteristic spe-
cimens, all of which are common in the West Indian seas. One

82 Mr. R. C. Taylor on the Geology of Cuba,

of the distinguishing characters of this old coral rock is that
it is for the most part made up of a branching species, which
appears to have existed at that time in great profusion, but
which we have failed to discover living in the vicinity on the
present reef. This ramose coral of the beach, when worn by
the action of the waves, reminded me of forms which were
nearly similar, which I remember to have seen at the base
of the chalk at Hunstanton Cliff in Norfolk, and to which
I made reference more than fourteen years ago in an article
in the Philosophical Magazine, First Series, vol. lxi. p. 82.

Our notice of these different aged reefs would be incom-
plete did we stop here. We have remarked that there is a dif-
ference of level, amounting to full twenty feet, perhaps thirty,
between the outer and the inner reef. Now as the coral in-
sects do not live above high-water mark, and indeed are sel-
dom seen living above the extreme low-water level, and com-
monly are several feet below it, it would appear that this an-
cient inner reef, which passes inland, was produced under
different circumstances of relative elevation of the sea and
land ; and that either the sea has been depressed to a depth
corresponding with the existing reefs of the coast, or, what is
more probable, that the land has been elevated since the con-
struction of the old reefs, not only here but at more distant
points.

We have also to note that the Zoophytes differ decidedly in
the two reefs, and therefore the circumstances which promoted
the growth of genera and species in one case, were changed
or were absent in the other.

Among the Mollusca also of the old reef the greater part,
(although common to the seas of these latitudes, like the
corals,) consist of different species to those now living in the
vicinity of the recent reef, or that are thrown up on the pre-
sent beach ; and we looked in vain for some which exist in
great profusion, and may be seen living at low water, at the
base of the old coral reef.

We conceived that a further confirmation of the supposed
change of level suggested itself in the prevalence of extensive
fissures in the old coral bed, where it slopes towards the sea
at low water. These cracks, which seem to imply displace-
ment and disturbance, may be traced separately many hun-
dred feet, commonly running parallel with the coast in an east
and west direction.

Putting these facts together, one is led to conclude that other
agents have been in action besides the mere erosion of the ocean
waves, or an occasional and temporary elevation of its waters;
and although we look to a miK-h less remote date for these

On the Fossil Jaw of a gigantic Quadrumanous Animal. 33
operations, we are perhaps not widely wrong in ascribing them
to some such causes as have produced such remarkable changes
of position in, and modified the composition of, every rock on this
sideofthe island of Cuba. This influence, towards the west, has
manifested itself by the injection of petroleum and bituminous
matter, not only in large quantities into the fissures of the
stratified rocks, but into the solid rocks themselves, and even
filling cells in the veins of chalcedony by which they are tra-
versed. In the quarter of which we have attempted to draw
the foregoing sketch, this influence is seen in the partial vitri-
fication of the serpentine and allied rocks; in the admixtnre
or proximity of igneous rocks ; in the conversion of masses of
quartz into a species of porcelain ; in the kneading into the
most contorted and fantastic forms the old stratified beds ;
in the obliteration, to a great extent, of the planes of stratifi-
cation of the limestone ; in the destruction of the traces of
organic remains which there is reason to conceive existed in
that formation ; and in the conversion of the whole series into
a compact, unstratified, and apparently homogeneous mass.
Philadelphia, March 1837. R. C. T.

V. On the Fossil Jaw of a gigantic Quadrumanous Animal al-
lied to the genera Semnopithecus and Cynocephalus. By
Lieuts. W. E. Baker and H. M. Durand, Engineers*

YELL, when combating the inconclusive evidence ad-
■" vanced in support of the theory of the progressive de-
velopment of organic life, notices the absence of remains of
quadrumanous species in a fossil state, and the hypothesis
which this circumstance has by some geologists been consi-
dered to countenance. He, however, draws attention to the
fact, that the animals which are found in subaqueous deposits
are in general such as frequent marshes, rivers, or the borders
of lakes, and that such as live in trees are very rarely disco-
vered ; he adds, moreover, that considerable progress must
be made in ascertaining the contemporary Pachydermata be-
fore it can be anticipated that skeletons of the quadrumanous
tribes should occur. Considering the great number of relics
assignable to the Fachydermata, Ruminantia, and Fera?, which
the Sub- Himalayan field has produced, it is not therefore sur-

• From the Journal of the Asiatic Society of Bengal, vol. v. p. 739 etseq
This paper forms one of a series, by the same authors, on the Sub-Himala-
yan Fossil Remains of the Dadupur collection. Dr. Falconer and Capt.
Cautley's Memoir on the Sivatherium giganteum, another Sub-Himalayan
Fossil, will be found in Lond. and Edinb. Phil. Mag. vol. ix. p. 193 et seq.
Third Series. Vol. 1 1. No. 64. July 1837. F

34 Lieuts. W. E. Baker and H. M. Durand on the

prising that at length the half jaw of a quadrumanous anim«I
should be brought to light: the circumstance, however, being^
interesting in several respects, we have not deferred its com-
munication until further research should put us in possession;
of more perfect specimens ; the chances are against the pro-
bability of more being brought in for some time — in the in-
terval it may be as well at once to add to the Sub-Himalayan
list of fossils one species belonging to the order of the Qua-
drumana.

The specimen in question was found in the hills near to the
Sutlej, and it appears from the attached matrix to have been
derived from a stratum very similar in composition to the one
described as occurring at the Maginund deposit. The frag-
ment consists of the right half of an upper jaw; the molars as
to number are complete; but the first has lost some of its ex-
terior enamel : and the fifth has likewise had a portion of the
enamel from its hind side chipped off. The second and third
molars are a good deal worn, and the state of the fourth and
fifth such as to indicate that the animal was perfectly adult.
The canine is small, but much mutilated, its insertion into the
jaw and its section being all that is distinct.

From the inspection of the molar teeth, the order to which
the animal belonged is sufficiently evident; but there is enough
of the orbit remaining to afford additional and very satisfac-
tory proof; the lower part of 'the orbit and the start of the
zygomatic arch being very distinct, would alone remove all
doubt from the subject ; the orbits of the Quadrumana being
peculiar and not easily to be confounded with those of other
animals.

On comparison with the delineations of the dentition of this
order of animals given by F. Cuvier, the fossil bears some re-
semblance to the genus Semnopitkecus; the section of the canine
and the form and size of the false molars are very similar to
the exemplar taken by F. Cuvier from a head of the species
[Semnop.~] Maurtis, a species found in Java: hadthedrawing been
taken from the [&] Entellus, a species which inhabits India, the
comparison would in this instance have been more satisfactory ;
the Maurus being chosen as the type, and no mention made
of other difference except length of canines, the various spe-
cies may be supposed to present no material departure from
the type in form of molars. The third molar in the fossil is so
much worn as not to admit of being compared with drawings
from unworn teeth ; the fourth is like that of the Maurus, but
the fifth does not resemble the analogous molars of any of the
existing species as represented by F. Cuvier, for the fossil
tooth possesses a small interstitial point of enamel at the inner

Fossil Jaw of a gigantic Quadrumanous Animal. 35

side, which does not appear to have place in any of those de-
lineated. The incisors are absent, but the intermaxillary is
■clearly distinguishable.

Were it not for the size of the canine and the fifth molar,
the specimen presents some resemblance to the genus Macacus,
given as the type of the genera Macacus and Cynocephalus ,•
the smallness of the canine and the large size of the molars
cause the fossil to approach more nearly to the Semnopithecus

Fig, I. nat. dim.

b a

than to the Macacus ; the difference is, however, great be-
tween the two, for the [5.] Entellus is said to attain the length of
three and a half feet, whereas the length of the fossil animal, if

F2

36 Dr. Turner's Chemical Examination of

the space occupied by the molars and their size be deemed
sufficient ground for a conjecture, must have been equal to
that of the PithecusSatyrus: — the space taken up by the molars
is 2*15 inches. This circumstance, and the differences before
pointed out, clearly separate the fossil from the species be-
longing to the genera Cynocephalus or Semnopithecus. The
specimen is imperfect, but it indicates the existence of a gi-
gantic species of quadrumanous animals contemporaneously
with the Pachydermata of the Sub- Himalayas, and thus supplies
what has hitherto been a desideratum in palaeontology — proof
of the existence, in a fossil state, of the type of organization
most nearly resembling that of man.

Note.— Fig. 2 is a little foreshortened in order to show the
bottom of the orbit at a, which in an accurate profile view is
hidden by the ascending part of the orbit, the section of which
is seen at b.

Both figures were taken with the camera lucida.

VI. Chemical Examination of the Colouring Matter of the
Green-sand Formation, By the late Edward Turner,
M.D., F.R.S.L. $• E., Professor of Chemistry in University
College^ London.*

THHE colouring matter of green-sand sometimes appears in
-*■ the rock of its ordinary green tint, and sometimes in grains
of so deep a green that they seem black. The former gene-
rally occurs in sand, or where the sandstone is porous, and in
this state an ochreous appearance is often observed, due to
the green particles being partially decomposed, and their iron

* From the Transactions of the Geological Society, vol. iv. part ii. p. 108.
Dr. Fitton, in whose paper on the strata below the chalk the above com-
munication by the late Dr. Turner is inserted, notices in the following
terms the subject to which it relates:

" (10.) The green matter, which abounds in this stratum [the upper green
sand] near Wissant, on the opposite coast of France, has been examined by
M. Berthier * ; who found it to consist principally of silica and protoxide of
iron, with ten per cent, of^ potash. For the purpose of comparing the green-
sands of different places and formations, my friend Dr. Turner, Professor of
Chemistry in the London University, was good enough to examine some
specimens from the upper and lower green-sands of Folkstone, of theVale of
Wardour, and the Boulonnois, and also particles of the same kind which
abound in the sand and concretions beneath the Portland stone in the Bou-
lonnois, and in England. I subjoin the result of this examination, whence
it appears that in all these cases the green matter is of the same nature. A
slight examination of the green particles, which Sir John Herschel had
previously the goodness to make for me, intimated the same results."

"• Cuvier and Brongniart, t Environs de Paris, 2nd edit. 1822, p. 249.
See also Annnlcs dcs Mines, iv. 1819, p. 623; and v. 1820, p. 197."

the Colouring Matter of the Green-sand Formation. 37

having passed into a higher state of oxidation ; whereas the
black-looking grains are met with in highly calcareous sand-
stone, where the texture is too firm to admit of the percola-
tion of water. From either kind of rock the green matter may
be obtained by washing with water and subsidence, since the
colouring matter subsides less readily than grains of quartz, and
more readily than calcareous and argillaceous substances. For
the purpose of analysis it is best procured from those calcareous
sandstones where the cement predominates, as in the neigh-
bourhood of Hythe and Folkstone in Kent. On reducing
such samples to powder, washing away the finer particles with
pure water, and separating any adhering carbonates by dilute
muriatic acid, the colouring matter is left, mixed only with
small grains of quartz. It then always appears in the form
of earthy particles of a deep green tint.

The green matter, when not previously weathered, is very
feebly attacked by concentrated acids, even by the nitro-mu-
riatic. It gives out water when heated, and becomes brown
from its iron passing into the state of peroxide. As it has
been supposed to owe its green colour to the presence of phos-
phoric acid, it was carefully examined, with the view of de-
tecting that acid, if present. It was accordingly fused with
carbonate of soda, the alkaline filtered solution neutralized by
nitric acid, and evaporated to dryness, and the neutral so-
lution tested by nitrate of silver and nitrate of lead. Of two
samples of green-sand, thus examined, one was found to be
quite free from phosphoric acid, and traces only were detected
in the other. The former was also free from lime, and the
latter contained but a small portion. It is hence obvious, that
neither lime nor phosphoric acid are essential constituents of
the colouring matter of green-sand, and their presence must
be regarded as casual.

In order to determine the chemical constitution of the co-
louring matter, I collected some green particles from the cal-
careous sand of Eastware-bay, near Folkstone, removing all
foreign matter as far as possible, by washing with water and
dilute acid. The only impurity which I could detect after
this treatment consisted of small grains of quartz, the quantity
of which varied in different samples.

A portion of green particles thus purified, very free from
oxidation, and dried at 212° Fahr., lost 7*0 percent, of water
when heated to redness.

Another portion of the same sample was fused with carbo-
nate of soda and the earthy ingredients subsequently separated
and weighed in the manner usual in such analyses.

A third portion was heated with carbonate of baryta, and

38. The Rev. R. Murphy's Remark on an Error

examined for potash, traces of which were readily found.
According to the total result, the green particles consist of

[M. Berthier's analysis of the green
particles from near Havre gave
the following proportions: —

Silica 50-0

Protoxide of iron ... 21*0
Alumina 7'0

Silica 48-5

Black oxide of iron 22*0

Alumina 17*0

Magnesia 3*8

Water 7*0

Potash traces

98-3

Water 110

Potash 10-0

99-0.]

It is superfluous to speculate on the precise atomic con-
stitution of the green particles, since they were not obtained
in a state of perfect purity. The ingredients which appear to
be essential, both from the quantity in which they occur, and
their constancy in the colouring matter of green-sand from
different localities, are silica, alumina, oxide of iron, magnesia,
and water. I should hence consider the green matter as a
hydrated silicate of alumina, magnesia, and black oxide of
iron, and as being, in all probability, the true green earth, or
earthy chlorite of mineralogists. The analyses of chlorite
hitherto published are so discordant as to prove, either that
different compounds have been examined under the same
name, or that the specimens under examination were very im-
pure. The essential ingredients, however, appear to have
been the same as in the subject of my analysis.

Though the foregoing description applies more immediately
to the colouring matter of the green-sand from the vicinity of
Folkstone, I have obtained similar results on examining that
from Hythe and several other places. Indeed, from the ex-
amination of many samples of green-sand collected by Dr.
Fitton from various localities in England and France, I be-
lieve the colouring matter to be precisely the same in all.

VII. Remarks on an Error of M. Fourier in his Analyse des
Equations. By the Rev, R. Murphy, M.A.

To the Editors of the Philosophical Magazine and Journal.

Gentlemen,

T^HE first part of M. Fourier's posthumous work on the

-*■ analysis of determinate equations was published in 1831,

the editor being M. Navier, of the Academy of Sciences of the

of M. Fourier in his Analyse des Equations. 39

Institute : I am not aware that any succeeding part of this
work has been published since that date.

The first part commences with a synoptic exposition of the
whole work, and from this Expose, which is rather diffuse, but
clear in its language, and which contains the announcement
of several theorems, the demonstrations of which are reserved
for the succeeding parts, there can be no doubt that the
author has committed some grave errors in the application of
recurring series to the solution of numerical equations.
M. Navier's attention may, through this medium, be directed
to expunge or correct those parts of the unpublished manu-
script referred to from p. 7 1 to 75 of the Expose.

(1.) Let a recurring series A, B, C, D, E, F... be formed
by the known method of Bernoulli and Euler, the successive

R C D
quotients of which, viz. —r- > -^- 3 -pr 9 &c- converge to the

A 15 v^

first (when real, greatest) root of a proposed equation ; from
this let a second series be formed, of which the terms are
AD— BC, BE-CD, C F-DE, &c; the successive quo-
tients of this series, says M. Fourier, converges towards the
sum of the two first roots. This is incorrect, for when these
quotients are convergent, they give the product instead of
the sum of the two first roots.

To prove this, let a, /3, y, &c. be the roots of the proposed
equation, a, /3 being the two first, that is, greatest, abstracting
from sign, when real, and when conjugate imaginary quantities,
such that a /3 >y8, &c.

Let u, represent the general term of the first recurring
series, and vx of the second, formed as above indicated, and
let C, C, C", &c, c, c, &c. represent quantities invariable
with x,

then vs = 2/^+3 — ux+1 us+2

and us= Caf+C S* + CT/ + , &c.

Hence vx = c(a/3)* + c' (ay)*+c"(/3y)*+, &c.

that is, making for abridgment

P,= c + C' [f) +«-.(£)* + , &c;

and as x increases it is clear that P^ converges to c, and there-

P b

fore the limit of -§^- is unity, and consequently that of -— t?

is a |3 and not « + £.

Example. Given x2 — 2 x— 3 = 0; roots —1 and 3.

40 On an Error o/M. Fourier in his Analyse des Equations.

The first series is recurring; take 1, 2 as the first two terms
and 2, 3 as the constants of relation.

First series 1, 2, 7, 20, 61, 182, &c.

Second derived series 6, —18, 54-, —162, &c.
The successive quotients of the first series converge to the
greatest root 3, and those of the second series are exactly the
product —3 of the two roots, and not the sum which would
be +2.

(2.) A, B, C, D, E, &c. being as above the primitive recur-
ring series, if another be formed such as A C— B2, B D — C,
&c., the successive quotients converge to the product of the
first two roots (p. 72.). This is correct, and may easily be
proved as in the preceding case.

(3.) From the primitive series, Fourier adds, 3 other recur-
ring series may be deduced by rules we have announced [in the
MS. of sixth book]. The first will give by its successive con-
verging quotients the sum of the 3 first roots, the second will
determine the sum of their products two by two, and the third
their continued product, (ib.)

The first two announcements here contained must be wrong ;
the third is most probably right ; for if the successive quotients
of a converging series gave a 4 - /3 4- y, its general term would
bevs= Cj (a + j3 + y)*+C2(a + jS +&)* + ,&<•. Such a series
cannot be derived in the above manner from ux = Ca*+ 0/3*
+ C" y*, &c ; and if it could it would not give the three first
roots, but the three roots of greatest sum, which may be very
different; for the same reason a/3-fay + /3yis not to be thus
obtained from a recurring series deduced from the primitive,
but u 0 y may be easily so found, and the value belong to the
three first roots, for their product must stand also first amongst
the products, though their sum may not amongst the sums.

The knowledge of a + j8 as well as a/3 would, no doubt,
give at once the real and the imaginary parts of a conjugate
pair of impossible roots ; but Fourier's method does not ob-
tain the first, as has been shown, and therefore his observa-
tions (p. 74-.), " et, ce qui est remarquable, on connaitra pour
chaque racine imaginaire, la partie reelle, de cette racine, et
le coefficient de l'imaginaire. Voila Pusage le plus etendu
que Ton puisse faire de la methode de series recurrentes," &c. ;
and (p. 75.) ■* Les proprietes que nous venons d'enoncer sont
incomparablement plus generates que celles qui ont ete connues
des inventeurs, et des auteurs qui ont traite depuis la meme
question," must be received with considerable deductions.

2, Bateraan's Buildings, Soho Square, Robert MuRPHY.

London, May 20, 1837.

t 41 ]

VIII. Investigation of Formula for the Summation of certain
Classes of Infinite Series. By J. R. Young, Professor of
Mathematics in Belfast College.

[Continued from vol. x. p. 124, and concluded.]

JET us take A of the form

n (n + p) (n + 2p) ... (n + nip)

then, by the general relation referred to, we may substitute
for it the expression

j_r 1

mp L n (n + p) (n + 2p) ... [n + (m— l)p]

-J \.

H + 2 p) ... in + mp)J

n* l (n+p) (// + 2p) ... (n + mp).

Now, by the same relation, we may for the first expression
within the brackets substitute

1 r 1

/

(m -\)p ^n* ^n + p\ (W + 2p\... [n+(m- 2)p]

_^ I 1

n l (n + p){n + 2p).» [n + (m - l)p]f

and for the first of these we may make a like substitution ; so
that by proceeding in this manner we shall at length arrive at

_L r l 1 i

2P \n*(n+p) n*~l(n + p) (n + 2p) J
and finally at

L/JL 1 1

P W nK~1{n+p)J
whence a rule may be easily deduced for the summation of a
series of the proposed form, provided certain subordinate se-
ries can be summed. As an illustration of this suppose x = 2,
and put for abridgement

1?+ (n+p)* + (n + 2py + &c*= *. ,

n{n + p) 7 (n+p) (n + 2p) T {n + 2p) (n + 3p) TOtc— ?l
1 1

n(n+p)(n + 2p) + (n+p) (» + 2p)(n + Sp) + &C'-S*

Third Series. Vol. il. No. 64. July 1837. G

42 Prof. Young's Investigation of Formula? for

1 l

n(n+p)...(n + mp) (n+p) [n + (m+l)p'] C **

then we have the following rule for the summation of the infi-
nite series :

\ L ! L &C

«*(w+p) (n + mp) T (n + p)*(n + 2p)...[n + (m+l)py '

From I take Sj and divide the result by p ; from the quo-
tient take S2 and divide the result by 2p; from the quotient
take S3 and divide the result by Sp; and so on, till the di-
visor becomes m p9 which will furnish a quotient equal to
the sum of the proposed series.

As to the values of the subtractive quantities, Slf S2, S3,
&c, they are at once obtained from the fundamental relation
with which we set out. Thus,

s, = -L

1 p n

1 s,

s* =

2p n (n + p) 2 (n + p)

g = 1 = SSg

3pn(n+ p) (n + 2p) 3 (n + 2p)

... m [n -J- (m — l)pY

As an example let it be required to find the sum of the in-
finite series

+ ~* s , 5 + ..,,,.. + &c.

I2 . 2 . 3 . 4, 22 . 3 . 4 . 5 T 32 . 4 . 5 . 6

in which w = 1, p = 1 and w = 3.

The values of Sl9 S2, S3, are, in this case,

S» m 1, S2 = T, S3 = -,

hence, arranging these in a row and prefixing the subtractive
sign, the operation by the rule will be as follows :

"~T """is

6

f-

*2 5
12 8

*2 49 Q

36 ""^le^^1

P'

** 5
6 4

** 49
12 72

the Summation of certain Classes of Infinite Series. 43

If the series to be summed were

1 1

1*. 3.5.7 + 3*. 5 . 779 + &°''

in which p = 2, the process would be this? viz.

JL JL A

2 12 90

•£ z!_A ^!__L ^!_ JL7_ _s

8 16 4 64- 12 384 1080 ~~

8 2 16 3 64 180

It would be easy, by imitating the steps of the preceding
investigation, to deduce a rule for the summation of the infi-
nite series

n(n+p)....(n + mpf + (n + p) ... 0 + (m+ I) j?f + &C*

This rule would differ from the foregoing in the following
particulars, viz. instead of Sl9 S2, S3, &c. we shall have to
employ

Si + — 2» S2+ w(w+/,j*> S3 + w(w + i,)(w + 2^' &c->

and these, instead of being subtracted as before from the se-
veral quantities placed under them, must themselves be dimi-
nished by those quantities.

It is clear that when n and p are each unity, as in the first
example above, the values which here supply the place of
Sp S2, &c. will be the doubles of these quantities.

As an example, let the series

1 1

1 . 2 . 3 . 42 + 2 . 3 . * . 5* + " &C*

be proposed, in which w = 1, p ;= 1, m = 3,

■ JL _L

2 9

6 2""6 12 " T08^36=S"m'

6 6 2 36 12

44 Formula for the Summation of Infinite Series,

By comparing the several steps of this process with those
in the working of the first example, we are led to conclude that
the aggregate of two series, like this last and that of the first
example, will always be accurately expressed in a finite frac-
tion, provided the factors in the denominator be even in num-
ber, and that the difference of the two series will also be a
finite fraction, if the number of these factors be odd. In all
other cases the sum and difference will involve tt2. Thus the
difference between the two series

1 _J_ _J_ - ir* 5

l2.2.3 + 22.3.4 + 32.4.5 + *C' ~ 12 ~ ~8

and

+ A a .2 t- „ , -a + &C. = — -

1 .2.3* ' 2.3.42 3.4.5s r 12 4

is — ; so that actually subtracting and dividing by 2, we have

1 1 1 0 1

+ &c. = —

]2 . 2 . 32 T 22 . 3 . 42 J S* . 4 . 52 J 16 '

this series is therefore the square of the series
1 1 1

T7273 + 2 . 3 . 4 + 3 . 4 . 5 + &C#
It thus appears that every series of the form

1 1

+ &c.

l2.2.3...(m- 1)t»2 ' 22.3.4...;»(wi+ l)s

is accurately summable when m is odd, but not when m is

even.

Similar remarks obviously apply to the series

1 1

12.3.5... {m — 2)m*+ 3*. 5 . 7 ... m(m -f 2)2 + '

the sum of which is a determinable fraction only when the de-
nominator of each term consists of an odd number of factors.
In other cases the sum involves ir%.

Although in the foregoing illustrations the several terms of
each series are all connected together by the sign plus, yet a
glance at the general investigation will serve to show that the
several deductions hold when the terms are alternately plus
and minus.

[ *s ]

IX. On the Right Rhombic Baryto-Calcite, with reference
to Prof. Johnston's Paper in the Phil. Mag. for May 1837.
By Thomas Thomson, M.D., F.R.S. L. $ E., Regius
Professor of Chemistry, Glasgow.

To the Editors of the Philosophical Magazine and Journal.
Gentlemen,

'T^HE Number of the Philosophical Magazine for May, which
-■■ I received yesterday, contains a paper by Mr. Johnston
of Durham, entitled " On the composition of the right rhom-
bic Baryto-Calcite, the Bicalcareo-carbonate of Baryta of Dr.
Thomson." This paper makes it necessary for me to send you
a few observations, and to request their insertion in the next
Number of the Philosophical Magazine.

The mineral which constitutes the subject of Mr. Johnston's
paper came into my hands in the year 1834, being in a collec-
tion exposed here for sale by a mineral dealer from Alston.
It was new to me ; I therefore analysed it, and concluded from
my experiments that it was a compound of 1 atom of carbonate
of barytes and 2 atoms of carbonate of lime. I was not aware
when I published an account of this mineral in May 1835 that
Mr. Johnston had some months before noticed it in a paper
containing some ingenious speculations about isomorphism
(L. & E. Phil. Mag., vol. vi. p. 1.), till my attention was called
to his paper by my nephew, Dr. R. D. Thomson of London.
I had read the paper before my System of Mineralogy went to
press. But as the result of Mr. Johnston's analysis was different
from mine, and as my faith in the theory of isomorphism and
dimorphism was not very strong, I thought the best thing I
could do was not to refer to Mr. Johnston at all, as I had not
complete evidence that his mineral was the same as mine.

Last winter I received a letter from Mr. Johnston informing
me that he had repeated his analysis and found it correct, and
requesting me to repeat mine. At that period of our session
my time was so fully occupied with college business that it was
impossible to pay the requisite attention to the necessary steps
of an analysis. I therefore wrote him that at present I could
not spare time for experimenting, but that I would make a
point of repeating the analysis as soon as our session was over.

Accordingly, when the month of May arrived, I immediately
set about it. While engaged in it I was informed by a friend
that a paper by Mr. Johnston had been read to the Royal
Society of Edinburgh, in which he maintained the accuracy of
his own analysis and the inaccuracy of mine. I presume the

46 Dr. T. Thomson's new Analysis of the

paper in the Philosophical Magazine for May (vol. x. p. 373.)
is the same that had been previously read in Edinburgh.

The analysis of a double carbonate of lime and bary tes is
very easy. Mine was made during the winter session, in a
laboratory where a number of practical students were con-
stantly engaged in experimenting. It was possible therefore,
as I stated to Mr. Johnston, that some accident vitiating my
results might have taken place without my knowledge. I de-
termined in the first place the constituents of the mineral, and
then ascertained the quantity of carbonate of barytes from the
nitrate left when the dry salt was digested in alcohol. Here
the analysis stopped. For I was not able for more than a
fortnight to analyse the nitrate of lime, and it was overturned
accidentally by one of the students. But from the known weight
of the mineral dissolved and the quantity of nitrate of barytes
obtained I inferred the composition of the mineral.

I have now finished three successive analyses of this mine-
ral. For the greater security they were made in a separate
room which my practical students seldom entered, and I
watched over all the steps of the analysis in person. I shall
here state the steps of the process, that Mr. Johnston may re-
peat it if he should feel inclined.

The first analysis was made upon 22 grains, the second on
20*1 grains, and the third on 15*8 grains of the mineral. It
will be sufficient if I give a detail of the third analysis, because
I consider it as the most accurate.

1. The 15*8 grains of the mineral were put into a flask
along with dilute nitric acid, and digested on the sand-bath.
They dissolved with the exception of 033 grain of sulphate
of barytes. On testing the nitric acid employed I found in it
a sensible quantity of sulphuric acid. Hence I conclude that
this sulphuric acid was the cause of the appearance of the pre-
sent sulphate. In the first analysis the sulphate of barytes
undissolved weighed 0*2 grain, and in the second only 0'08
grain. These differences were doubtless connected with the
quantity of nitric acid employed to dissolve the mineral.

2. The nitric acid solution was filtered, evaporated to dry-
ness, and redissolved in water. The solution was opal-co-
loured, and deposited when left at rest 0*27 grain of a white
matter, which proved when examined by the blowpipe to be
sulphate of barytes. This, added to the preceding quantity,
makes 0*6 grain of sulphate of barytes, equivalent to 0*5 grain
of carbonate of barytes.

3. The aqueous solution of the nitrates was evaporated to
dryness, and the residual salt being put into a flask was di-
gested in a quantity of alcohol of the specific gravity O'BOO.

Right Rhombic Baryto-Calcite. 47

The flask was corked, the alcohol was heated to the boiling
point, and then left to digest for some hours on the salt. It
was then drawn off by a sucker, an additional portion of the
same alcohol was poured on the undissolved salt, and the di-
gestion continued as before. A third portion of the same al-
cohol was finally added and the whole was thrown upon a
filter to collect the undissolved nitrate of barytes. After being
dried in a heat of 300° this nitrate weighed 1 2*05 grains, equi-
valent to 9*08 grains of carbonate of barytes.

4. All the alcoholic liquids were collected together in a small
retort, and the alcohol distilled off till only a few drops of
liquid remained in the retort. It was taken out of the retort,
evaporated to dryness, and digested again in alcohol of 0*800.
The whole dissolved with the exception of a dirty yellowish
black powder, which was separated, and weighed after ignition
0*3 grain. When examined before the blowpipe it proved
to be oxide of manganese, not quite free from iron.

5. The alcoholic solution was distilled as before. It was
then evaporated to dryness, and the salt that remained heated
in a platinum crucible till the nitric acid was decomposed.
The residue was digested in weak nitric acid and the undis-
solved portion collected on a filter, ignited, and weighed. It
amounted to 0*67 grain, and was red oxide of manganese, not
quite free from iron. This with the preceding 0*3 grain makes
0*97 red oxide of manganese, equivalent to 1*45 grain of car-
bonate of manganese.

In my first analysis I separated the manganese by caustic
ammonia, but I could not in this way free the nitrate of lime
from all traces of manganese. In the second analysis I em-
ployed with the same object sulphohydrate of ammonia ; but
this method only succeeded imperfectly. Even the process
employed in the third analysis did not render the lime quite
colourless, though the manganese and iron remaining were
very small in quantity.

6. The nitrate of lime was converted into sulphate, ignited
and weighed.

The results of the analysis are

Carbonate of barytes 9*58 or 60*63

Carbonate of lime 4*77 or 30*19

Carbonate of manganese 1*45 or 9*18

15*80 100*00
These numbers are equivalent to

3*92 atoms carbonate of barytes,
3*83 atoms carbonate of lime,

1 atom carbonate of manganese, with a little carbonate
of iron.

48 Sir Edward Ffrench Bromhead's Remarks on

Doubtless the true composition is

4? atoms carbonate of barytes,
4 atoms carbonate of lime,
1 atom carbonate of manganese and iron.
Thus it appears that neither Mr. Johnston nor myself had
given a correct analysis of the mineral. It is a triple instead
of a double salt. I failed in discovering the manganese, in
consequence of having neglected to examine the calcareous
residue : Mr. Johnston failed in consequence of dissolving the
mineral in muriatic instead of nitric acid. This last acid
should always be used in examining the earthy carbonates,
because it enables us to see by the colour when any iron or
manganese is present.

A name derived from the constituents of so complicated a
mineral would be unwieldy. Perhaps the term bromlite, de-
rived from its best known locality, would be as unexception-
able as any. I am, &c,

Thomas Thomson.
Glasgow, June 3, 1837.

X. Remarks on the present State of Botanical Classification,
By Sir Edw. Ff. Bromhead, Bart., M.A., F.R.S.L.8>E*

FT seems to be agreed among botanists that the natural fa-
■*■ miiies must be arranged upon some new system ; and it is
also understood that the first attempt must consist in forming
natural alliances or assemblages of such as are in immediate
undisputed affinity with each other. Each family must be
related to every other family within the alliance, and I have
elsewhere explained the artifice by which a first approxima-
tion may be made.

The question of linear arrangement is not necessarily con-
nected with this stage of the inquiry ; if such be the order of
nature, the primary alliances will throw themselves into se-
quence almost spontaneously ; if not, some other principle will
shortly show itself. In the mean time, to give the future re-
sult fair play, we should endeavour to place the families within
our alliances in their natural order of transition, as we endea-
vour to arrange genera within families and species within ge-
nera. The tendency to circulation will no doubt always offer
difficulties ; it would almost seem as if the progress of deve-
lopment were represented by a thread wound spirally round a
rod, on which the point immediately above another appears

* Communicated by the Author

the present State of Botanical Classification. 49

to be the nearest, though distant by a whole round of the
spiral.

The extent of these alliances does not yet rest upon any fixed
principle. Linnaeus and Adanson throw plants into fifty-eight
assemblages, and we must consider a botanical family of that
day as representing the alliance of our own time. Bartling
makes sixty classes or alliances. The annexed table makes
sixty alliances also, averaging each about five families. Those
of Dr. Lindley are more numerous, averaging rather less than
three families; he seems to have looked for consolidation in
h:s groups, and precision in the alliances. The alliances of
the table sometimes correspond with Dr. Lindley's groups, as
in Curvembryosa?, Aggregosce, Glumosa?, Spadicosa?, but they
more generally correspond with his alliances; the smaller al-
liances of Dr. Lindley must however continue under any
scientific classification as suballiances.

In the revised table, the improved nomenclature of Dr.
Lindley is of course usually adopted; his work on the Natu-
ral System must henceforth be a standard of reference every-
where; and there is much convenience in the definite manner
by which such reference points out the tribes and genera in-
tended to be included. His happy manner of designating
the alliances by a termination in ales is also adopted. In
amending the nomenclature, it were to be further wished that
botanists would regularly designate all the families from ge-
neric names, throwing aside names from species or obsolete
genera, and all characteristic or arbitrary or mutilated names.
Such a regular system might, by a slight modification of the
termination, lead hereafter to a convenient mode of indicating
the position of each family in the general system.

The limits of families are often at present more a matter
of taste than of definite distinction: Arnott has in doubtful cases
made good use of suborders as superior to tribes and sections.
The average points to five families for each alliance, and it
may be as well to lean towards that number; nothing would
be more easy than to reduce the whole to that standard ; we
sometimes have the choice of more than one combination, or
sometimes a more easy adaptation to a ternary or senary
division. Numerical symmetry is, however, a suspicious cir-
cumstance in natural history, though it is possible that an
antecedent, normal, and succeeding state may occasionally be
distinctly marked.

In the first approximations for forming the table, the cha-
racters were studiously kept out of sight. Every one must
feel, on trial, the bias against evidence, where it is required
to modify a scheme for the admission of something additional,

Third Series. Vol. 11. No. 64% July 1837. H

50 Sir Edward Ffrencli Bromhead's Remarks on

and also the tendency to cut off families at the limits of an
alliance for the sake of rounding the character. After the first
grouping the investigation of characters will, of course, be
found useful ; it will settle the limits of an alliance, where a
family has stood ambiguously between two; it will negatively
settle the place of many doubtful families; it will shake hete-
rogeneous alliances, and confirm such as are sound.

The characters must be formed on the whole structure ; it
may in a few instances be possible to point out an assemblage
of families by some happy peculiarity, but such is not the plan
of nature, in which even species require an enumeration of
many parts. The utmost extent of simplification will be a
statement of the normal structure (the Nixus of Dr. Lind-
ley), followed by remarks on the limits of deviation and equi-
valent changes. The error in this case has arisen from the
received notion, that every species passes imperceptibly into
some other ; such, however, may not be the case, — a change of
one particular part generally implies, in natural history, some
corresponding change of every other part, so that families
may differ more abruptly than genera, and alliances more ab-
ruptly than families. In some families the differences of ad-
joining species are much greater than in others.

A collection of characters is necessary also for ascertaining
the nature of the properties which usually extend over a suc-
cession of families ; the properties which most conveniently
distinguish genera are often of little value to distinguish fami-
lies, and those which separate adjoining families will probably
have little further range. In this research it is mortifving to
find a property running through the greater part of an alli-
ance, and often passed by in the remainder as being unimpor-
tant within the usual limits of classification. The characters
may too frequently amount to nothing, or indicate merely that
there is not a deviation from general normal structure ; but
such were some of the characters of Jussieu. They may
often be negative, but such are more definite than any other,
and may hereafter be pushed to any extent, so as to form dif-
ferential characters between any two alliances whatsoever.

Results apparently trivial should be admitted, where they
offer themselves, as it is impossible to foresee what may serve
to illustrate the general progress of structure. Where a pro-
perty occurs through an alliance, with comparatively trifling
exception, it should be given, and the exception stated ; the
place of the excepted family may be shaken, or some remark-
able equivalence of structure may be discovered.

Bartling very properly gives the lead to the structure of
the stem, foliation, and inflorescence, as Linnaeus does in the

the present state of Botanical Classification. 51

elegant sketches of his Botanical Philosophy. Those pro-
perties are not often used in distinguishing genera, and are
comparatively neglected by many late writers; they will pro-
bably hereafter rise to importance, and it may be found useful
to refer to the older writers, who laid so much stress on folia-
tion.

In giving the characters it is necessary to use a modified
language of a greater breadth of expression than usual.

I have collected some materials for ascertaining the founders
of the different alliances in the table; and the first publisher
must be so considered, even were it thought to be the result
of an indistinct happy accident. P'ew writers can take the
range of a whole science and instinctively select from the mass
whatever is well founded. Writers may see the truth placed
before them, but seeing it mixed up with objectionable matter,
they may throw it aside, and after long inquiry and many
qualifications, may find on reference the final result of their
labburs to be the same. Science herein differs from literature,
that the truth must bring two writers to the same point; but
it is also true that we may let the result of our reading digest
with the mass of our ideas, until we mistake for the produce
of our own minds what we met with elsewhere. Frequently,
by a kind of compulsion, after long research the views of
others are adopted. The annexed table has thus been most
materially improved, and was in some parts new cast, from the
many new affinities and assemblages discovered by the acute-
ness of Bartling and Lindley.

Of the 60 alliances in the table, (in the next page) it is highly
satisfactory to find that nearly 50 have been substantially in-
dicated by the first names which botany can produce : —
Agardh, Bartling, Brown, Caesalpinus, Decandolle, Hedwig,
A. L. de Jussieu, Ad. de Jussieu, Lindley, Linnaeus, Morison,
Ray, Reichenbach, Richard, Rudolphi, Schultes, St. Hilaire,
Wallenbergh. The particulars of their discoveries, and the
characters of the botanical formations and alliances which I
have prepared, would extend these remarks much too far.

[See the " Intelligence and Miscellaneous Articles " of the
present number for some remarks on the introductory passages
of the foregoing paper, prepared for insertion as a note, but
for which there is not room in this place. Edit.]

M 2

52 Sir Edward Ffrench Bromhead's Remarks on

THE ULVACEOUS RACE*.

[Fucaceae,1 chondraceae,1 ULVACEAE,1 nostocaceae,1 diatomaceae,]

(f) Confervaceae,1 characeae, equisetaceae, (siirillariaceae,)

Ophioglossaceae, danaeaceae- OSMUNDACEA E-gleicheniaceae, poly podiaceae,

Cycadaceae, ephedrace.x, casuarinaceae,

f Myricaceae, platanaceae-(moraceae,2) iTLMACEiE-ffothergilleae,) (empetraceae,)

stilaginaceae, scepacea?,
Trewiaceae, hensloviaeeae -batideae, (f)URTICACEAE, cannabineae, datiscaceae,
Lacistemaceae, chloranthaceae, garryaceae, (nageiaceae^-piPEKACEAE-saururaceae,

podostemaceae,

Ceratophylleae, hippurideae,3 callitrirhaceae, hai.orageae, trapaceae,
Circaeeae-fGENOTHERACEAE-montinieae, [flythraceae, (f)rhizophoraceae,

vochyaceae, -f-combretaceae,
Memecylaceae, melastomaceae, alangiaccae, lecythidaceae-barringtoniese,] +myr-

TACE^E-puniceae,

Pyraceae, amygdaleae, fchrysobalanaceae-fsanguisorbeae, (neillieae4)-quillaiae-

spiraeae, (tJROSACEiE-fpotentilleae,
(f) SAXiFRAGACEiE-cunoniaceae-baueraceae, aristoteleae-philadelphaceae, (fgala-

cineae,4) escalloniaceae, bruniaceae,
Ribesiaceae, [fmelocactaceae, CUCURBITACEAE, begoniaceae, loasaceae,]
[Fouquieraceae, crassulaceae, mesembryanthaceae, poktuxacaceae, vivianieae,'-

j-silenaceae-f alsinaceae, ]

(f)IHecebraceae, fCHENOPODIACEAE,9 fphytolaccaceae,9 fpolygonaceae,
mirabiliaceae-salvadoraceaa,

Staticeae-plumbaginaceae, polemoniaceae, cobaeaceae, diapensiaceae.hydroleaceae,
Hydrophyllaceae, BORA GIN ACE AE, heliotropiceae, ehretiaceae, cordiaceae,
Nolanaceae,[(t)verbasceae-(f)digitaleae-sfilpiglossideae,soLANACEAE-(cestracea?,)]
convolvulaceae, cuscutaceae,

Leiphaimeae,1* [^retziaceae,) menyantheae, fGENTiANACEAE, spigeliaceae,
(f)APOCYNACEiE, asclepiadaceae, carisseae-rauwolfiea?,] potaliaceae-logani-

aceae, lygodysodeaceae,
f Cinchonaceae, opercular! neae, galiaceje, lonicereae-sambuceae, apiacea?,

(f )Araliaceae, loranthaceae, (f )hamamelaceae, coRNACEAE-hederaceae,6 f vitaceae,
GERANIACEiE, surianaceae, limnanthaceae, tropaeoleae-balsaminaceae, foxa-

lidaceae,
[Reaumuriaceae-(tamaricaceae,) elatinaceae-Hnaceae, cistaceae,] resedaceae, po-

lygalaceae-krameriaceae,
Tremandraceae, cappareae-cleomeae, brassicaceae, fumarieae, papaveraceae,
[NYMPHiEACEAE, nelumbiaceae, (f)cephalotaceae,hydropeltideae-podophyl-

leae, paeonieae,7
Cimicifugeae^-clematideae-franunculaceae, sarraceniaceae,] aristolochiaceae,

nepentbaceae, (f cytinaceae,9)

(f )Pistiaceae, fhydrocharaceae, alismaceae, butomaceae, pontederaceae,
Commelinaceae-philydraceae, xyridaceae-restiaceae-desvauxiaceae, cyperaceae,

AVENACEjE, cocoaceae,
Cyclanthaceae, pandanaceae-TYPHACEAE, (f)acoraceae-araceae-ambrosinieae, tri-

glochinaceae, fnaiadaceae,

* The symbols and references are explained in p. 54.

the present state of Botanical Classification. 53

THE USNEACEOUS RACE.

+f Fungi,... (Byssaceae,) [calyciaceac,2 graphidaceae,2 USNEACEAE,*] endocar-

Riccieae-marchantieae, jungermanniaceae, andraeaceae-bryaceae,
Salviniaceae-marsileaceae, isoe'teae6-fLYCOPODIACEAE, lepidodendreae,*
(Salisburiaceae)-ftaxaeeae, cupressinae, fpinaceae-araucarieae,

Liquidambraceae, salicaceae, betulaceae, carpineae-'-fcorylaceae, juglandaceae,
Anacardiaceae-spondiaceae, burseraceae, chailletiaceae, nitrariaceae-(neuradeae,)

RHAMNACEAE,
Coriariaceae, (f)EUPHORBiACEAE, stackhousiaceae, celastraceae-staphyleaceae-

fhippocrateae, erythroxyleae,

Malpighiaceae, (f)aceraceae, jesculace^:, millingtonieae-sapindaceae, caryocara-

ceae,
fClusiaceae, marcgraaviaceae, HYPERICACEAE, (oehranthaceae)-carpodon-

teae, •fcamelliaceae,
Rhodolaenaceae, humiriaceae, (hugoniaceae)-(canelleae,) meliaceae-cedrelaceae,

limoniaceae,
Amyridaceae, fconnaraceae, mimoseae-detarieae, swartzieae-fFABACEAE,

geoffroyeae-caesalpinieae,
Moringaceae, [worraskioldia^-ffrankeniaceae-sauvagesiae, (f)parnassieae,7 dro-

seraceae, -f-vioLACEAE,
fPASSIFLORACEAE-malesherbiaceae, tumeraceae, caricaceae, belvisiaceae,

patrisieae-ffiacourtiacese,
fBixaceae, pangiaceae, samydaceae, HOMALiACEiE,] aquilariaceae,

fDaphnacese-penaeaceae, fproteaceae, ELAEAGNACEAE, nyssaceae5-fsanta-
Jaceae-anthoboleae, olacaceae,

Oleaceae-jasminaceae, columelliaceae-gesneraceae, pinguiculaceae, acanthaceae,

cyrtandraceae-bignoniaceae-pedaliaceae,
Stilbaceae, selaginaceae, myoporaceae, fverbenaceae, L AMI A CE AE-ocimoideae,
Buddleieae-buchnereas, fgratiolese, (fveroniceae,) hemimerideae, antirrhineae-

gerardieae-faHiNANTHEAE, orobanchaceae,
Monotropaceae-(t)pyrolace£e,-f-ERicACEAE,epacridaceae,androraedeaB,vacciniaceae,
CAMPANULACEAE-lobeliaceae, stylidiaceae, pongatiaceae, goodeniaceae-

scaevolaceae, brunoniaceae,
Asteraceae-cichoraceae-mutisiace?e-CYNARACE^;,9 valerianaceae, calyceraceae,

dipsacaceae-globulariaceae, fplantaginaceae,

tPrimulaceae-fMyitsiNACEAE, achrasaceae, (f)styraceae-diospyraceae, ilicaceas-

brexiaceae, pittosporaceae,
+Zygophyllaceae, fltUTACEiE, fxanthoxylaceae, simarubaceae, ochnaceae,
Dipterocarpaceae, elaeocarpaceae-(f)tiliaceae, byttnerieae-dombeyae-bombaceae,

Malvaceae, (f)sterculiaceae,
Myristicaceae, hernandiaceae, illigeraceae, cassythaceae, lauraceak,
Atherospermaceae, monimiaceae, calycanihaceae, illicieae-MAGNOLIACEiE,

fdilleniaceae,
Schizandreae, fanonaceae, (f)berberaceae, lardizabaleae, menispermaceae, * * *

Smilaceae-dioscoreaceae-froxburghiaceae, f asparagaceje,9 (f)juncaceae-gilliesi-

aceae, fhemerocallaceae,9 (t)melanthiaceae,
Iridaceae, apostasiaceae, ORCHID ACEiE-vanillaceat, zingiberaceaB-maranta-

ceae musaceae, famaryllidaceae,
Hypoxideae agaveae, fBROMELiACEAE, wachendorfieae7-fhaEinodorac«ae, burman-

niaceae, taccaccae, . . . f Balanophoraceae,"

54 Mr. Prideaux on the Deduction of the Dew-point
MEMORANDA.

A series of Families in immediate and continuous affinity with each other, is
called an alliance, and is indicated by a termination in ales:— Ex. Osmundalet
are the Ferns.

Parallel Alliances are called formations*, and are indicated by a termination
<u(r;— Ex. Lamiosae include Lamiales and Boraginales, the Nucamentosae of
Dr. Lindley.

Series of successive alliances are called unions: — Ex. The Passifloral Union in-
cludes Violales, Passiflorales, and Homaliales, nearly'the Parietosae of Dr. Lindley.
[ ] Indicates that the order of succession among the families so included is not

settled.
( ) Indicates that the evidence for the station is more conflicting than usual.
f Indicates that the Family or Tribe may be compound. Tribes are occasion-
ally inserted to show transitions.
The Nomenclature of Dr. Lindley's System is usually taken as the standard.

(1) Agardh's Fucoideae, nor idea;, ulvaceae, nostochinee, diatomere, confervoideee.

(2) Here separated.

(3) Link.

(4) D. Don.

(5) Jussieu.

(6) Bartling.
(?) Arnott.

(9) Chenopodiaceae here includes Scleranthaceae-amarantaceae-fchenopodiacew.
Phytolaccaceae includes Tetragoniaceae-phytolaccaceas-petiveriaceae.
Cytinaceae includes Rafflesiaceae.

Cynaraceae — followed by (Xeranthemeae)-calendulaceze-arctotideac.
Asparagaceae includes ConvallarinaJ-parideae-asparageae-aloinae-anthericew.
Hemerocallaceae includes fScilleae-hemerocallideae-tulipeae.
Balanophoraceae includes Cynomoriaceae.

XL Observations on the Deduction of the Dew-point from the
Indications of the Wet-bulb Thermometer, and on the Detec-
tion of minute quantities of foreign Matters diffused in the
Atmosphere ,• with Notices of Apparatus. By John Pri-
deaux, member of the Plymouth Institution ; in a letter to
Mr. Bray ley.
Dear Sir,

THE wet-bulb thermometer, preferable to other hygrome-
ters from the permanence, directness, and simplicity of
its action, has the inconvenience of its indications being not
only subject to necessary calculations, but also, hitherto, to
considerable discrepancy in the principles on which these
computations are made; and to corresponding differences in
the resulting dew-points, even supported by irreconcileable
experiments. The pages of the Philosophical Magazine have
been so largely occupied in the discussion of these principles,
that it is not my intention to go much into them on the pre-
sent occasion ; on which I will offer little more than a compari-
son between Dr. Apjohn's table in vol. vii. p. 471, with that
of Dr. Mason in Thomso?iys Records, vol. iv. p. 109.

* A term used by Reichenbach.

from the Indications of the Wet-bulb Thermometer. 55

In Dr. Apjohn's I omit the barometrical column, which
Dr. Mason finds to be needless (p. 101), and that of the cal-
culated dew-points, in which the error is generally on one
side, occasioned, as the author supposes, by an error in one of
the elements; and I substitute, for the sake of comparison with
Mason's, a column (5) of differences between the dew-point
and dry bulb thermometer; having for the same purpose
changed the order of arrangement to that of these differences.

In Mason's table such numbers only are taken as come into
comparison with Apjohn's; and to facilitate this comparison,
three columns (6, 7, 8) interpolated, illustrating his method
of obtaining the dew-point, viz. doubling the difference be-
tween the wet and dry bulb (col. 8), + a correction for wind
(col. 7)> and deducting the product (col. 10), from the indi-
cation of the dry-bulb thermometer.

1

APJOHN.

Added Columns.

MASON.

Dry-bulb
Thermo-
meter.

Wet-bulb
Thermo-
meter.

Differ,
ence,
Wet and
Dry-
bulb.

Dew-
point.

Differ-
ence,
Dew.
wint and
Dry-
bulb.

Correc-
tion for

Wind,
subtract-
ed from

col. 8.

Correc-
tion for
Current
of Wind.

$4

M

• a

Differ-
ence,
Wet and
Dry-
bulb.

Differ-
ence,
Dew-
point and
Dry-bulb

1

2

3

4

5

6

7

8
15-

9

10

68-

60 3

77

55-

13-

12 5

2-5

75

17-5

713

63-

8-3

57-5

13-8

1 3-33

2-67

16-

8-

18-67

81-

62-2

8-8

565

14-5

1417

2-83

17'

8-5

19-83

72-

62-

10-

55-1

169

1667

3-33

20-

10-

23-33

69-

58-9

101

51*5

175

69-

58-6

10-4

51-3

177

17-5

3-5

21-

10-5

24-5

71-7

eo-

117

.51 2

205

1917

3-83

23-

11-5

26-83

72-

60-

12-

51 3

20-7 1

77*

65-

12-

57 2

19-8 I

20-

4-

24-

12-

28-

75-2

63-2

12-

55*

20 2 J

73-

60-3

12-7

513

217

20 83

4-17

25-

12-5

29 17

76-

63-3

12-7

54-7

21-3

77-5

64-5

13-

563

21-2

21-67

4-33

26-

13-

30 33

76-

615

14-5

513

247

24-17

4-83

29-

14-5

33-83

78-

62-2

15-8

513

26 7

26-67

5-33

32-

16-

3733

79-

62

16 4

50-9

28 1

83-

6(ro

165

56 8

26-2

27-5

55

33-

16-5

385

83-

65-8

172

545

28-5

28-33

5-67

34-

17-

39-67

84-6

67'

176

56-

28-6

2917

583

35

1?5

40-83

82-2

64 3

17*9

50 9

31*3

92-

69-

23-

54 1

379

30-

6-

36-

18-

42*

91-8

68-6

23-2

54-1

377

38-34

7-66

46-

23-

53-66

995

67'

23-5

50-8

39-7

3917

7-83

47-

235

54 83
63-

98-5

71-5

27-

555

43-

45-

9-

54

27-

Now it is remarkable that if instead of adding this correc-

56 Mr. Pricleaux on the Detectiori of minute

tion (col. 7), which was found by experiment, we deduct it
from the double difference (col. 8), we get (the numbers in
col. 6, corresponding with) the differences between Apjohn's
dry-bulb and dew-point (col. 5) ; and so close is this corre-
spondence when the slight differences in the leading numbers
(cols. 3 and 9) are taken into the accompt, that we can hardly
persuade ourselves that it is accidental.

Hence Apjohn's experiments fix the dew-point at double
the descent of the wet-bulb —the effect of current ; and an
upward current, in some proportion to the rate of evaporation,
must obtain over an evaporating surface. But Mason's num-
ber to be deducted, which takes the effect of current in + , is
both deduced from and supported by direct experiments.

It further follows from the premises, and is apparent in the
table (cols. 5, 6, 8, 10), that the mean of their respective dif-
ferences between the dry-bulb and dew-point is simply double
the difference between the dry and wet-bulb ; a relation pre-
viously deduced from numerous experiments by August,
Bohnenberger, and others. Berzelius in giving us this informa-
tion (Tr. de Chim., viii., art. Hygrometre) has not referred
to the works in which these experiments are detailed : if you
have the means of hunting them out, and giving such abstracts
as will enable British meteorologists to judge of the compara-
tive degree of confidence to which they are entitled, it may
render an important service to meteorology. The best in-
struments are subject to the influence of various circumstances
in taking the dew-point ; and the experiments of Apjohn, in
which most of these interferences are obviated, are objected
to by Dr. Hudson, in a paper immediately accompanying
their publication.

In the mean while it must be remembered that Dr. Ap-
john's dew-point is that at which the air, by passing through
water, took up moisture, and should be under rather than over
saturated, so that it would, of course, not deposit any at that
temperature. Dr. Mason's, on the other hand, was that at
which a metallic surface became dewed ; the air depositing
moisture, and being of course supersaturated. Between
these two a few degrees of temperature would intervene; the
mean of which, the true point of saturation, would be the
same as ahove deduced from the tables. It therefore becomes
a question whether this simple deduction may not bring us
nearer the truth, on the long run, in the present state of our
knowledge on the subject, than more elaborate calculations or
even observations with our best instruments, considering the
temporary character of such observations, and the influence
of circumstances to which they are liable.

I have been led into these inquiries, in considering the pre-

Quantities of foreign Matters diffused in the Atmosphere. 57

sent difficulty of ascertaining chemically the causes of differ-
ences in the atmosphere, produced by the diffusion through it
of infectious and other matters in very minute proportions.
It would seem that the aqueous vapour likewise diffused
brings down with it when condensed, such miasmata, &c,
as were either merely suspended, or, being dissolved, have
much affinity for water. In fact we find the glass of win-
dows and other non-absorbent surfaces here incrusted with
salt, for three or four miles inland, after long southerly and
westerly winds; our stream of water from Dartmoor al-
ways acquires a slight saline impregnation before it reaches
the town; and in malaria and other unwholesome climates
the stranger is particularly cautioned to avoid the evening
dews. This natural dew, if collected in sufficient quantity,
would probably be most fully impregnated ; but when this
cannot be done, a common glass carboy, filled with a cheap
refrigerating mixture and suspended over a funnel in a gentle
current of air on a dewy evening, will collect a sufficient quan-
tity for experiment. Rain is too dilute, and the clouds from
which it falls too migratory to answer the purpose. For
matters little attracted by water, reagents of more energetic
affinities may be suspended in shallow vessels, kept cold, when
requisite, by refrigerating mixtures beneath. But when the
air is very dry, when it is necessary to concentrate upon a
very small quantity of reagent the foreign matter in a large
quantity of air, or to know the quantity of air submitted to its
action, the test may be contained in a tube like that of Liebig
for condensing carbonic acid, &c, in organic analysis, (de-
scribed below,) and the air blown through from a pair of small
cylindrical bellows, the cubical contents of which are known;
or for greater accuracy, by a condensing syringe, containing
an exact number of cubic inches ; though the bellows are
more conveniently portable. To thoroughly extract the
foreign matter, the air may be repeatedly passed through the
tube by receiving it at the end in a bladder furnished with
stop cock, &c, having a second bladder,
which can either replace it when full, and
removed to the entering end, or it may be
returned from one to the other, through a
tube with a two-way cock, to save the trou-
ble of screwing and unscrewing.

Liebig' s condensing tube for carbonic acid,

tyc, in organic analysis. — For carbonic acid

the three lower buibs are filled just above

the connecting tubes with solution of potass, through which

it bubbles up and keeps the liquid in agitation; the two

Third Series. Vol. 1 1. No. 64. July 1837. I

58 Professor Forbes' s Experiments on

bulbs in the legs are safety bulbs. For ammonia, &c, the
appropriate reagents are, of course, substituted.

m

tan

^

Modification of Gahn's Blowpipe. — I employ a modifica-
tion of Gahn's blowpipe which is, perhaps, more convenient
in use, and more clean and agreeable to handle. A is a piece
of brass tube closed at the end, and having a boss near
the end perforated to admit the beak at a. B is the beak,
fitted to a by grinding, and bent at an angle of 135°,
which I find more convenient than a right angle for di-
recting the jet upward or downward by a little turn of the
beak without disturbing the support, and for minutiae in
operating. It can be turned in any direction. C is a piece
of glass barometer tube, fitted into A by binding round with
fine thread, and fixed with a little plaster of Paris : thus A
becomes the condensing chamber ; and when moisture is col-
lected there in so large quantity as to affect the beak, (but
which will never take place in a single operation, however long,)
the beak is withdrawn and the moisture blown out through
a. D is a bit of hard wood turned, and cemented round C;
where it serves as a stop to its entering A, and as a good hold-
fast in operating; the smallness of the tube in many blow-
pipes giving the fingers some difficulty in commanding them,
which occasions the preference felt by so many operators for
the blowpipe with a condensing bulb in the middle.
I am, dear Sir, yours very truly,
Plymouth, April 19, 1837. J- PniDEAUX.

XII. Account of some Experiments made in different Parts of
Europe, on Terrestrial Magnetic Intensity, particularly with
reference to the Effect of Height. By James D. Forbes,
Esq., F.R.SS. L. Sf E., fyc, Professor of Natural Philosophy
in the University of Edinburgh.*

1 . HPHE Council of the Royal Society of Edinburgh having,

A on my application in 1832, entrusted me with Han-

steen's magnetic intensity apparatus, in their possession, I feel

* From the Transactions of the Royal Society of Edinburgh, vol. xiv.,
having been read before that society December 19th, 1836.

Terrestrial Magnetic Intensity. 59

it to be my duty to communicate to the Society the results
then and subsequently obtained with it.

2. The instrument consists of a mahogany box 5 inches
long, 4 broad, and 2 deep, with sides and top of glass, having
also a wooden tube, screwing into the top, for containing a
silk-worm's fibre about 5 inches long, by which the magnetic
needle is suspended so as to place itself horizontally, and after
being caused to deviate from its point of rest, the time of any
given number of oscillations in a horizontal plane is mea-
sured,— whilst a graduated circle in the bottom of the box in-
dicates its arc of vibration.

3. The needles which accompanied the instrument, when
originally sent from Norway, are two in number, one a cylin-
der 3 inches long and 0*1 inch in diameter, is marked on its
case " No. 1." The other is shorter, thicker, and heavier,
and from its form has always been called the " Flat " needle.
These were the needles used with this apparatus by Mr. Dun-
lop, in the experiments made in Scotland at Sir T. M. Bris-
bane's expense, and published in vol. xii. of the Society's
Transactions. A reference to that volume will show clearly
Professor Hansteen's and Mr. Dunlop's method of observa-
tion, which, essentially, I have always followed.

4. If we assume the magnetism'of a needle to remain in-
variable, the intensity of the earth's magnetism at different
places, or at the same place at different times, will be (on the
principle of the pendulum) inversely as the square of the time
required to perform a given number of vibrations in infinitely
small arcs, under the different circumstances. But various
adjustments have to be attended to, and corrections applied.

5. Nothing more portable or more simple than the instru-
ment in its present form can be desired. These requisites are
no doubt obtained at the expense of some accuracy. Mr. Snow
Harris has shown* that the influence of the surrounding air
upon the needle gives rise to considerable errors, especially
when the needle is so small and light, as in Hansteen's ap-
paratus. But greatly to enlarge the needle, and to connect
an air-pump with the apparatus, is nearly equivalent to de-
priving the traveller of its use altogether. Hansteen's instru-
ment was the constant companion of my pedestrian excur-
sions, and had it been in any other form, the present obser-
vations would probably never have been made. Besides all
this, there are sources of error arising from imperfectly known
and irregular variations of the earth's intensity, and equally
or more important ones from changes of magnetic intensity in

* Edinburgh Transactions, vol. xii. p. 1.— See also the Observations of
Professor Bache ; American Phil. Trans., vol. v.

12

60 Professor Forbes's Experiments on

the needle itself, which the improvements in question do not
affect. Until by a regular and long-continued series of ob-
servations, such as those likely to be undertaken at Green-
wich, magnetism shall be reduced to more of a science than it
is at present, we must beware of pretending to illusory accu-
racy in a traveller's detached experiments. Those about to
be detailed in this paper, will sufficiently indicate the degree
of comparability of observations made with Hansteen's instru-
ment, such as it is, and which is by far the best test of their
real value. It has certainly rather exceeded than fallen short
of my expectations.

§ 1. Adjustments and Method of observing.

6. Hansteen's instrument contains no provision for securing
the horizontality of the needle, which is of considerable im-
portance. The needles have, indeed, sliding collars of sus-
pension, which may be altered with change of dip, but the
box has no adjusting levels. I have always* used a small spirit
level for adjusting the bottom of the box, and then, as care-
fully as I could, made the needle hang parallel to it, but the
adjustment was troublesome and unsatisfactory.

7. The needle being levelled and allowed to come to rest,
it was drawn out of its position of rest f, but always in a
horizontal plane, by the approach of a piece of iron or steel
(usually a penknife), and the process repeated until the semi-
arc of vibration exceeded 20°, if 300 vibrations were to be
observed, or 10° if 100 only were observed, as was more
usually the case. This last deviation from Professor Han-
steen's practice was not adopted without due consideration.
The large commencing arc necessary in order that the vibra-
tions might be distinguishable at the close of 300, increased
greatly the errors pointed out by Mr. Harris. Moreover,
there seemed less chance of error in combining several series
of 100 vibrations taken in succession, than in using a single
series of 300, which, from the time it occupies, is more liable
to be interrupted and rendered useless by a gust of wind, or
a momentary relaxation of the painful attention required to
be exerted by an unassisted observer. Besides, the mere error
of the observed time, depending on the eye and ear of the ob-
server, will not exceed even in 100 vibrations the uncertainty
arising from causes impossible to eliminate, — indeed falls

* I cannot answer however, for two or three of the first observations
hereafter to be quoted.

f As the torsion of the silk fibre must have some influence, it is not un-
important to remark, that the same thread which was adapted to the in-
strument in August 1832, has been used ever since.

Terrestrial Magnetic Intensity.

61

much short of it: yet this is the only error which we diminish
by increasing the vibrations in a series to 300.

8. When the semi-arc of vibration had diminished to 20°,
or to 10° (as 300, or 100 vibrations were to be observed), the
counting of vibrations commenced, — the hour, minute, se-
cond, and decimal, of the beginning or 0th vibration being
noted, and the second and decimal only for each succeeding
10th vibration, until 360 vibrations (in the first case) or 160
(in the second) were observed. These seconds of time are
arranged in columns, so that the times of the 0th, 100th,
200th, 300th vibration, run along the same horizontal line as
do the 10th, 110th, 210th, 310th, &c The time of the 0th
being then subtracted from the time of the 300th (or 100th),
we have one value of the time of 300 (or 100) vibrations. The
10th, from the 310th (or the 110th) gives a second value, and
so on to the 60th and 360th (or 160th), which gives in all
seven values of time of 300 (or of 100) vibrations ; the mean of
which seven values is taken (the minutes being of course sup-
plied), and the hour, minute, and second of conclusion. The
thermometer (inclosed in the box) is consulted at the begin-
ning and end, and its indications registered. The rate of di-
minution of the semi-arc of vibration is also observed, its
continued bisection being indicated opposite to the instant at
which it occurs in a column parallel to those already named.
The rate of the chronometer is likewise to be determined.
An example will best illustrate all this.

MAGNETIC INTENSITY.

Place,

Ther.

Greenhill, near Edinburgh. Reaum.

Date,

7th May, 1833. Beginning, 5h 3m 4P-6 18°-0

Neediest. End,.... 25 34-

Mean

5 17°'3

, 1765

Arc.

Sec.

Arc.

Sec.

Arc.

*•'

Sec.

300 Vibrations.

o

20

41-6

47-8

520

56-7

m s

18 151

18-3

o

240

28-3

32-5

14-2

54-7

10

0-4

5-3

9-2

14-5

310

36-5

o

40-8

457

14-7

8-5

14-0

5

17-7

220

13-5

450

49-8

54-2

58-2

132

21-7
58-3

260
3-3

30-7

77

345

12-8

m s

350

39-0

43-6

Mean, 18-1400

11-1

15-8

19-8

= 1094-00

Rate + 3*

62 Professor Forbes' s Experiments on

9. My method of observing was to keep the chronometer
at the ear till the instant that the termination of a vibration
was observed, then to count five beats of the balance (corre-
sponding to two seconds), which affords time to bring the
dial-plate into view, and the seconds entered in the Table are
those read off at that time, namely two seconds later than the
absolute times. Thus the impracticable attempt to observe
two things at once by the eye is avoided. For this and some
other suggestions, I am indebted to my friend Captain P. P.
King, R.N. The observations are registered in lithographed
forms bound into volumes.

10. In the choice of stations I have been extremely parti-
cular, often at great personal inconvenience*. Places remote
from any trace of habitation have most usually been selected,
and in no case have intensity observations been made in a
house. The specialties of the sites will be noticed in the fol-
lowing Tables. I have invariably removed all masses of iron
from my person ; and in my later experiments even took
the precaution of carrying thin shoes, in order that the heavily
nailed ones which I usually wear, might be removed to a di-
stance. The chronometer, too, has generally been held at
some distance from the apparatus. But some direct experi-
ments lead me to believe that the influence of the two last-
mentioned sources of error is insensible.

§ 2. Corrections applicable to the Observations.

1 1 . When the mean of seven values of 100 or of 300 vibra-
tions has been taken, as above explained, a variety of import-
ant corrections remain to be applied.

12. I. Rate of Chronometer. — The following rule due to
Professor Hansteen is simple and accurate : — " The logarithm
to five decimal places of the observed time is taken, unity is to
be added to the fifth decimal place for every two seconds per
diem that the watch goes slow; and unity subtracted for every
two seconds that the watch goes fast." The demonstration is
too simple to require notice. The following is a table of cor-
rections : —

Table I.

Log. Additive. Log. Additive.

Rate + 0sec 0-00000 Rate — 0sec 0-00000

2 0-99999 2 0-00001

4 0-99998 4 000002

6 0-99997 6 0*00003

8 0-99996 8 0-00004

10 0-99995 10 0-00005

* None but those who have been engaged in observations of the very
same description, where the eye, the ear, and the memory are all actively
employed, can have an idea of the difficulty of always finding sites free from
the interruptions of curiosity, or natural obstacles.

Terrestrial Magnetic Intensity. 63

There is another chronometric correction worth mentioning,
arising from the necessarily imperfect division of the seconds'
circle of an enamelled dial-plate. In my watch this amounts
to a sensible quantity, and has often given an apparent discre-
pancy ]Xo the partial results of a series for which I was not
prepared. Upon investigation, I find, however, that the effect
upon the mean will always be so insignificant as to be hardly
worth notice.

13. II. Arc. — A correction due to the motion of the mag-
netic pendulum in circular arcs, cannot be considered as a
constant quantity, and therefore not affecting relative results,
1. Because the rate of diminution of arc varies considerably
in different experiments, and is directly deduced from the ob-
served law of diminution of arc; and 2. Because we some-
times have to compare observations of 100 vibrations having
an initial semi-arc of 10°, with 300 vibrations beginning at 20°.
The latter case having alone been considered by Hansteen,
I reinvestigated the theory of the correction, and confirmed
his numbers.

14. It is assumed that the arc diminishes geometrically in
consequence of resistance, the time increasing arithmetically.
The best observations I have made confirm the truth of this ge-
neral admission. Again, we have to recollect that, in conse-
quence of the degradation of the arcs, the reduction to infinitely
small arcs for the vibrations between the 0th and the 300th,
will be greater than between the 10th and 310th, &c, and that
the mean of all the corrections (taking this variation into ac-
count) must be applied. The law of the diminution of arc, or
the factor representing the ratio of the arc of one vibration to
that of the immediately preceding one, will be at once deduced
from observing after how many vibrations the arc is halved.
Let m be that number, then if r be the factor in question,
r™ = \ ; whence r =™ \/ £, which is known ; and therefore m9
together with the initial semi-arc of vibration, may be used as
the arguments for entering the following table of correc-
tions * : —

* Investigation. — Let » be the initial semi- arc of vibration (taken in parts
of radius), and r the ratio of its diminution by resistance in a single vibra-
tion.

Then, for the 1st, 2nd, 3rd, 4th, wth vibration,

The arcs will be ct, et r, » r3, m r2, u r

And, by mechanics (Poisson, art. 184.), the times occupied by these vibra-
tions will be (the time of an infinitely small vibration being unity),

1+T6' 1+T6-> 1+-W 1+T6--1 + fT

And the mean duration of the n vibrations is,

64 Professor Forbes's Experiments on

Table II.

Initial Semi. Arc = « = 10°. Initial Semi- Arc -a.- 20°.

No. of Vibrations observed = n = 100. No. of Observations observed = n = 300.

m Additive Log. m Additive Log.

70 9-99978 70 9*99969

80 « 9-99975 80 9*99960

90 9-99972 90 9*99953

100 9-99970 100 9*99946

110 9-99967 110 9*99939

120 9*99965 120 9*99933

130 9-99962 130 9*99926

I have every reason to think this correction to be accurate

on the whole : the agreement of the two modes of observation

being in general very close.

15. III. Temperature. — This extremely important correc-
tion it is very difficult to determine. Without an accurate
estimation of it, it would be vain to attempt to decide whether
or not the magnetic energy varies with height ; because at great
elevations the temperature being always diminished, the inten-

M = 1 + - l + r2 + r* + r* - r*(l'~1) = 1 + "*

16 * n i ' 16 (1 ~rz)n

Hence the mean duration of n vibrations,

~2 1 r2n . / ct \2 .

Fromthe Oth to the nth is 1 + -^ . !_ = l + ( — ).A

16 (1 — r2 n) V 4 /

10th to the (n+ 10th) is =1 + /_* Yriox2.A

(because the initial arc instead of ct is ct r10)
I 20th to the (n+ 20th) is =1 + (— V r20*2. A

60th to the (n+ 60th) is = 1 +(.fLY ,6o*e a

And the mean value of these deviations is
1 I /"Y A l+r20+^...-r-r^ / * x 1 - r'«

1+Vi7 a 7 =1+VT) 2<A-7(i-^)

The concluding factor may be called B ; and substituting the value of r
from the text, or (j})"1* we have

2 ft 140

A = _ a, B-~ »

r being independen
Corrected time =

whence the Tables are computed.

(the last factor being independent of »), and we have

Observed Mean Time

i !

.A.B.

0+t)

Terrestrial Magnetic Intensity.

65

sity would appear too great (the magnetic energy in iron being
increased by cold and diminished by heat). 1 therefore en-
deavoured to compare the intensity of the needles employed
within the range of temperatures usually observed. The ap-
paratus employed was of this kind. The needle was first al-
lowed to take the temperature of a heated room and vibrated.
Then everything else remaining the same (and of course any
local attraction which might exist being unaltered) the appa-
ratus was placed in a cylindrical glass jar, with ice in the bot-
tom, placed in a dish of ice, and covered with a glass plate
also covered with ice. A steady temperature, but little above
the freezing point, was thus attained, and the oscillation again
observed. These experiments were repeated many times.
One series was undertaken at Geneva in October 1832, an-
other at Edinburgh on four different days of August 1834.
Those for the needle, No. 1, were conducted with the most
scrupulous care, nearly 5000 vibrations having been counted
for this purpose alone. One set was discarded as differing
too much from the others, and the remainder agreed very
closely, although made under such different circumstances,
and at such different times. The result adopted for needle
No. 1 gave an increase in time of '00045 for a diminution of
temperature of 1° Reaumur, and vice versa ; for the flat needle
(determined from two concordant series, both observed at
Geneva on different days,) '00030. From these results the
following tables were calculated, giving the reduction in each
case to 0° of Reaumur (which being the scale attached to the
instrument, was always observed in these experiments). This
seems preferable to referring to any other arbitrary tempera-
ture, upon which observers do not generally agree.

Table III.

Additive corrections applicable iojive place Logarithms of the

Time, for the effect of Temperature.

NEEDLE, No. I.

FLAT NEEDLE.

Temp.
Reaum.

Correction.

Temp.
Reaum.

Correction.

Propor-
tional
parts.

Temp.
Reaum.

Correction.

Temp.
Reaum.

Correction.

Propor-
tional
parts.

1°
2
3
4
5
6
7
8
9

10

9-99980
999961
909941

9-99922
9-99902
9-99883
9-99863
9-99844
9-99824
9-99805

11°

12

13

14

15

16

17

18

19,

20

9-99785
999766
999746
999726
9-99707
9-99687
999668
9-99648
999629
9-99609

Corr.
°1 -2
•2 4
•3 6
•4 8
•5 10
•6 12
•7 14
•8 16
•9 18

■JO

2
3
4
5
6
7
8
9

10

9-99987
999974
9-99962
999949
9-99936
9-99923
999910
999898
9-99885
9-99872

11°

12

13

14

15

16

17

18

19

20

999859
9-99846
9-99834
999821
9-99808
999795
9-99782
9-99770
9-99757
0-99744

Corr.
°'l -1

•2 3

•a 4
•4 5

•5 6
•6 8
7 9
♦8 10
•9 12

Third Scries. Vol. 11. No. 64. July 1837.

K

66 Mr. Beke's Additional Remarks on the former extent of

16. I am disposed to think that the correction for tempera-
ture is always open to a certain degree of doubt. Perhaps
the condition of magnetism in the needle is not necessarily that
due to the temperature it possesses at the moment, but rather
to a temperature it had formerly. I think I have in some
cases perceived indications of this. The needle No. 1, which
is more slender than the " flat," seemed to be more steady in
its indications than the other, and as I have always placed
more reliance upon its indications, so the effect of temperature
was determined with most care.

17. IV. Variations in the Earth's Magnetic Intensity. —
These variations must affect observations of the relative inten-
sity at two places, if the observations be not simultaneous.
These variations are either (1.) secular, showing a progressive
change from year to year ; (2.) periodical, that is, subject to
short periods of variation and regular, as at different seasons
of the year, and at different hours of the day; or, (3.) acci-
dental, arising from the aurora borealis, or from unknown
causes*. The numerical laws of these three may be said to
be almost equally unknown ; the variations of the second class
have indeed been studied by Hansteen, Christie, Dove, and
others, but the results are not sufficiently accordant to permit
me to apply any of them to my observations. As, however,
the epochs are always recorded, this correction may be ap-
plied at a future time, and in a more advanced state of science.

[To be continued.]

XIII. Additional Remarks on the former Extent of the Persian
Gulf and on the Distinction between Babel and Babylon,
By Charles T. Bekf, Esq., F.S.A.
To the Editors of the Philosophical Magazine and Journal.
Gentlemen,

"CMiOM the length of time which has elapsed since the
A insertion of m}T last communicationf, I am led to conclude
that the controversy which during the last three years has oc-
cupied so many pages of your valuable journal is now at an end.
Before, however, allowing the subject to be entirely dismissed,

* My friend Professor Necker of Geneva has pointed out to me one of
the first recorded observations o( the influence of the aurora upon the mag-
netic needle, the more interesting because the coincidence was unnoticed
(apparently) by the observer himself. In Saussure's Voyages dans les Jlpes,
vol. iv. p. 300, that enterprising traveller notices an auroral appearance, ob-
served from the Col du Geant on the 12th of July 1/88, and in another
part of the same volume (p. 308), records, amongst his magnetical observa-
tions, the unsettled state of the needle during the whole of that evening.

f See Lund, and Edinb. Phil. Mag. for July 1836, vol. ix. p. 34, ei seq.

on the Persian Gulf, and on Babel and Babylon. 67

I am desirous of adding a few references and observations
which have since occurred to me.

With respect to the changes which have taken place in the
courseof the Euphrates, the authority of the Nubian geographer,
Ebn Idrisi, is important. This writer, after showing that one
branch of the Euphrates joined the Tigris, by which vessels
were brought down from Samosata to Bagdad, says that the
other branch, skirting the desert, divided itself into several
arms, of which one passed Tsarsar, another Alcatur, a third
Sura, and a fourth Kufa, and that all these arms terminated in
the lakes*, which lakes, as described in my former papers, will
have been formed, to the destruction of the course of the river,
by the same process of change which has also subsequently
annihilated them.

This change, as I have before stated, consists as well in an
alteration of the courses of the rivers as in an advance of the
land at the head of the gulf. And as upon this latter point
Mr. Carter regards the express statement of Pliny as a mere
" notion," adding that " certainly serious doubts may well
arise of the authenticity of the passage" in which it occursf, I
am glad to be able to refer to so valuable an authority as that
of the Rev. G. C. Renouard, who, tar from doubting the au-
thenticity of the passage or regarding the fact recorded in it
as a notion of the writer, says : " Nor can any doubt be en-
tertained as to the co?Uinual augmentation and change of this
coast, when we learn from Pliny (vi. 31) that Charax, at first
a maritime town, only 10 stadia (1| mile) from the sea, was
distant 50 miles from it according to Juba, and as much as
120 miles in his own time, (in the first century of our era,)
as he had heard from persons well-acquainted with the place. X*

* " Euphrates labitur deinde a Samosat, atque illinc ferre incipit naves
usque ad Baghdad. A Samosat postea excurrit per meridiem declinans ad
orientem...ad Hitz, ad Enbar ; indeque defluit adamnem Isa, ad Baghdad.
Jacet autein Baghdad secus Tigrim. Reliqua vero pars Euphratis fluens a
Rahaba, e tergo deserti, in varia dividitur brachia, quorum unum pergit ad
Tsarsar, aliud ad Alcatur, aliud etiam ad Sura, quartum denique ad Kufam,
et omnia ilia brachia varios in lacus sese immergunt.'' p. v. dim. iv. cited
in Base's Regnum Davidis, p. 154.

f See Lond. and Edinb. Phil. Mag., vol. vii. p. 197-

X EncycL Metrop. 4th div. vol. x. p. 256. I must not, however, omit to
cite on the opposite side of the question the authority of a writer of no
little renown, namely, Professor Heeren, who, in a treatise on the former
shape of the Persian Gulf, after making the voyage of Nearchus to cor-
respond with the present eastern coastof that »ulf,by using a stadium of eight
to the mile,— not less closely (it is worthy of remark) than Dr. Vincent has
done by employing a stadium of just half the length,- gives it as his opinion,
that the northern coast, in the time of Nearchus, probably excended much
further to the south than it does in the present dav ! His words are,

K<2

68 Mr. Binks on the Laws of Action of Voltaic Electricity,

On the subject of the distinction between the Babel of the
book of Genesis and the Babylon of Nebuchadnezzar, I have,
in conclusion, to adduce the authority of Diodorus Siculus,
who informs us that, at the time of the conquest of Babylonia
by the Assyrians under Ninus, Babylon itself was not in exist-
ence, although the country contained several other cities of
importance*. This statement is entirely corroborative of the
conclusion drawn from the various other authorities already
cited by me, namely, that the Babylon which was known to
the prophets, and which existed in the times of the writers of
profane history, was a totally distinct city from, and one of a far
more recent date than the Babel which was erected in the
plain of Shinar previously to the dispersion of mankind.
I am, Gentlemen, your most obedient servant,

Leipzig, March 23rd, 1837. Charles T. Beke.

XIV. On some of the Phcenomena and Laws of Action of Vol-
taic Electricity i and on the Construction of Voltaic Batteries.
By Christopher Binks. Addressed to J. Frederic Daniell,
Esq., F.R.S., Professor of Chemistry in King's College,
London. f
Dear Sir,

IN your letter addressed to Dr. FaradayJ, describing your
constant voltaic battery, you speak of seeking to reduce
thezincto a minimum comparatively with the surface of copper
employed in the same mass of electrolyte ; but it does not seem
to have been your intention to determine precisely what was
the proper relative proportion of the two metals. Subse-
quently to this remark in your letter, Mr. Mullins § has ex-
pressed his belief that the surface of zinc ordinarily brought
into action in such combinations is much greater than is
needed : but neither has he stated the precise results of ex-
periment upon this point.

In the same communication, and in allusion to his new bat-
tery, Mr. Mullins speaks of his having discovered the exist-
ence of a new principle of action in voltaic combinations. He
remarks, " In this battery the power is immense in proportion

u Admodum tamen probabile videri, continentem quondam magis versus
austrum procurrisse, partemqueejus non exiguam procedente tempore aquis
esse submersam, non dissimulaverim." Comment. Socict. Beg. Scient. Got-
t'mg. toni. xiii. CI. Hist. p. 138. See also an abstract of the treatise
printed in his Historische Werke, vol iii. p. 337, Gottingen, 1821.

• Kcct SKituovi Oi row; ^qvovc, i} fttv uvu ovaot. BoiQv'Aeov ovk tKTiop.ii/ri,
Kxra. Of t/)v Botfiv'hcii'Jtxv vtm^op u.^'koti "xcihfts ot^tciKuyoi. Lib. 11, c. i.

f Communicated by Professor Drniell.

X Philosophical Transactions, 1836. § Phil. Mag. for Oct. ,1836. p.285.

and on the Construction of Voltaic Batteries, 69

to the quantity of metals used, and arises, I conceive, from the
application of a principle which I believe is quite novel in the
construction of voltaic batteries, namely, that of diminishing
the metallic surfaces as the fluid in its onward passage accu-
mulates; thus acquiring increased force in proportion to the
smallness of the substance to which it is restricted." It was
in the absence of the information that would have been de-
rived from the promised communication from Mr. Mullins,
or of precise information from any other source, that the fol-
lowing experiments were begun, having for their immediate
object to determine what proportions should be preserved be-
tween the zinc and copper in any voltaic combination, and to
trace the existence and nature of the principle of action alluded
to in the above extract from the paper of Mr. Mullins.

Before the invention of your constant voltaic battery we
possessed no instrument upon whose regularity of action we
could depend, for either the establishing (by even an approxi-
mation to the truth) or the demonstrating of many of the laws
of voltaic electricity. The battery of Wollaston, or modifica-
tions of it, either as an elementary or a compound one, had ge-
nerally been employed in such investigations. But you have
shown that there is an uncertainty and variableness in its ope-
ration, of so great an amount as should surely preclude its
employment in experiments intended to decide upon the fun-
damental laws of the science.

It is, perhaps, to this circumstance mainly, or as much so
as to that of our possessing no common standards of compari-
son in the majority of instances, that we owe the conflicting
statements of the fundamental laws of the phenomena of gal-
vanism which pervade the various treatises upon it. Of such
conflicting statements we have one recent instance, among
very many, in which the previously admitted law of the con-
ductibility of wires of different lengths is called in question by
E. Lenz *, who substitutes in its place another law, of which
the expression is, that " their conductibilities are in an inverse
ratio to their lengths," in contradiction to that formerly held
of their conducting power being "inversely as the square root
of their lengths." I would submit that many other such laws
are not yet decided, since it has not been shown generally in
what way provision was made to guard against the irregular
operation of the exciting battery employed, or that experi-
menters generally were aware that such irregularities pre-
vailed, or at least, prevailed to so great an extent as has now
been shown.

* Scientific Memoirs, part ii. p. .'120. [See also p. 1 1 of the present Num-
ber.— ElHT.'J

70 Mr. Binks on the Laws of Action of Voltaic Electricity,

Let a sheet of common rolled zinc, carefully selected for its
apparent uniformity of surface and thickness, be amalgamated
in such a way as to secure the greatest uniformity in the distri-
bution of the mercury over its surface. Let plates be cut from
this sheet, exactly of the same size, and then associated with
corresponding copper plates ; and however well this may have
been done, and however exactly alike the plates and every at-
tendant circumstance may be, it will be found that no two of
the couples will give the same results in the same time, when
arranged as simple galvanic circles and acted on by acids in
the usual way. Whilst one zinc plate will lose 10 grains in
a certain time, another compared with it and apparently ex-
actly similar will lose perhaps only 6 grains, or, on the other
hand, as much as 15 grains. Out of innumerable instances I
have never been able to select two exactly alike, and in the
closest approach to perfect similarity in the amount of action
of any two which I have found there has still been between
them a difference of ^th of the whole amount.

Again, any one plate, associated with a copper plate as a
simple circle, will lose less the first time of its immersion than
during the second, of which the following is one taken out of
many such examples:

A plate of amalgamated zinc, arranged with copper as a
simple voltaic circle, and immersed (the acid being each time
renewed) during periods of 30 minutes each :

Table No. 1.

In the 1st time lost 8*8 grains
2nd 90 —

3rd 9-s —

4th 11-2 —

5th 13'0 —

6th H-3 —

And when at the end of these the plate was amalgamated
afresh and reimmersed, the action was reduced below its
first amount, namely, to 6*7 grains in the 30 minutes.

These sources of error, in cases where such elements are
used, are independent of many others well known to experi-
menters, such, for instance, as accidental differences in the
distance of the plates from one another, and the varying con-
ditions of their surfaces.

Again, the common rolled zinc of the shops is very impure,
and before undertaking investigations of phaenomena in which
comparisons of effects with the quantities of zinc consumed
and hydrogen evolved are needed, the proper equivalent of
the zinc actually employed must be determined.

In the midst of so many sources of error, against which the

and on the Construction of Voltaic Batteries. 71

utmost care can scarcely provide, it is but to be expected, so
long as the same materials are used, that the greatest contra-
riety of opinion will exist on points apparently so easy to de-
termine. A method of avoiding those errors which have their
origin in the irregularity of the mutual action of the acid and
zinc will be submitted to you towards the end of my letter.

In order to avoid a too frequent recurrence to description
in the course of this paper, I will, at this point, state generally
some of the precautions (beyond the common and more obvious
ones) that were taken to ensure accuracy in the results of the
experiments.

The magnetic needle was never resorted to as a measurer of
the amount of action or of the quantity of electricity developed;
but this was estimated by what appears to me to be the more
certain, though infinitely more laborious method, of finding,
by the balance, the equivalent of zinc expended, or by actually
measuring the volume of the evolved hydrogen. In no instance
was the one calculated merely from the volume or weight of
the other. In general both the balance and the meter were
employed, whatever the number of the series in any experi-
ment to be examined, and the number amounted in some cases
to as many as fifty. I had anticipated that some curious re-
sults would appear from this mode of testing the phaenomena,
and have not been altogether disappointed. Again, when plates
of amalgamated zinc were used in comparative experiments,
in which equal ones, or differing by a certain ratio, were wanted,
these comparative values were not estimated by the mere
measure of their surfaces, but, by actually finding the amount
of action upon them in a given time, by previous immersion
in acid of a kind similar to that intended to be used ; for an
equality in the extent of surface does not ensure an equality
of voltaic action, nor does that action increase in the same ratio
as the surface may be increased, as has hitherto been believed.
Again, the zinc employed throughout these experiments was
always of the same quality, indeed was cut from the same sheet,
and itsequivalent determined, with hydrogen as unity, and found
to be S4--5. And in order, as far as possible, to reduce the num-
ber of the conditions involved in these experiments and requi-
ring to be attended to and estimated, one of such was entirely
avoided, viz. that of variation in the distance between the two
elementary plates. Whether used in independent or compa-
rative experiments the mass of fluid interposed between the
zinc and copper plates was invariably equal to one inch. The
acid employed was the diluted sulphuric, and in those propor-
tions which have become standard ones, through their having
been used as such by yourself and Dr. Faraday. It is, per-
haps, almost needless to remark that in any case where local

72 Mr. Binks on the Laws of Action of Voltaic Electricity \

action was discovered to have taken place it was either pro-
perly allowed tor, the defective plate dismissed, or the experi-
ment wholly repeated, and that where comparative estimates
were made of the evolved gas or gasses, the proper corrections-
were made for temperature and pressure.

First Investigation. Part I.

To determine the relative proportions of the zinc and cop-
per needed to induce the maximum effect in the action of any
simple voltaic circle.

1st. To determine the influence and its extent of increasing
the surface of the copper plate beyond that of the zinc.

Experiments. — A plate of amalgamated zinc, measuring *
square inches on each face, was associated successively with
plates of copper, first of an equal size to the zinc and after-
wards of a greater size, and gradually increasing in the ratio
of the subjoined table. The times of immersion were each 30
minutes ; the acid, a mixture of 4j sulphuric (by measure)
and 100 parts water, and at the end of each time the acid was
renewed and the plate rinsed in clean water and weighed, when

(Table No. 2.)

1st, with the copper equal to the zinc, it lost 4*0 grains

2nd, twice the zinc, it lost... 5*2 —

3rd, 4 times the zinc, it lost 6*7 —

4th, 8 times the zinc, it lost 9*0 —

5th, 12 times the zinc, it lost 15*1 —

6th, 16 times the zinc, it lost 19*5 —

7th, 20 times the zinc, it lost 16*6 —

8th, 24 times the zinc, it lost 17*2 —

But throughout these experiments the same zinc plate was sub-
jected to the action of the acid, and that extending through eight
periods of thirty minutes each, or through four hours. And it
has been shown above in table No. 1 that a plate of zinc so
placed loses more in the second time of immersion than during
theirs*. Accordingly, to protect this examination from such
a source of error, another plate with the copper equal to it was
employed simultaneously and under like conditions, and was
weighed at the end of the same times, when it was found to
have lost in (Table No> 3#)

1st time, loss = 4*3 grains = *0"

2nd time, loss = 4*3 grains = *0

3rd time, loss = 4-4 grains = -1 In $ive increase

4th tame, oss = 4-6 grains = -3 I fig^ ^ immer_

5th time, loss = 4*9 grains = *6 [ .

6th time, loss = 5*3 grains =1*0

7th time, loss = 5*9 grains = 1*6

8th time, loss = 6*7 grains = 2*4,

and on the Construction of Voltaic Batteries. 73

which increase of action (reckoning from the third result) being
deducted from the results of the corresponding periods in the
former table, will leave that table to show the influence merely
of the increased size of the copper plates, which is the point
sought for. Therefore the table so corrected stands thus:

Table No. 4. corrected (from No. 2).

1 st, copper equal to zinc, loss 4*0 grains

2nd, : twice the zinc, loss 5*2 —

3rd, 4 times the zinc, loss ... 6*6 —

4th, 8 times the zinc, loss ... 8*7 —

5th, 12 times the zinc, loss ... 14*5 —

6th, 16 times the zinc, loss ... 18*5 —

7th, 20 times the zinc, loss ... 15*0 —

8th, 24 times the zinc, loss ... 14*8 —

From which it appears that the greatest amount of action be-
tween the zinc and the acid is induced when the copper plate
is 16 times larger than the zinc.

But in order further to test the accuracy of these results
eight distinct zinc plates were selected, as nearly as possible
alike, and the experiments repeated with the aid of a fresh
zinc plate during each time, when the results were exactly the
same as those exhibited in the corrected table No. 4.

This table, then, shows the proportion of the copper by
which the greatest effect is produced under the then existing
conditions of the arrangement. But it does not show us what
is the absolute amount of power gained by using this propor-
tion in preference to plates of an equal or of any other size ;
neither does it show whether the law it establishes will hold
good under varying conditions of the action of the arrange-
ment; whether, for instance, if its energy be increased or di-
minished, it will still require, to produce the utmost absolute
effect, that the copper should be maintained of a size 16 times
greater than the zinc.

To determine the former of these points let the result ob-
tained by the plates of equal surface in zinc and copper (which
we have in the first line of the above table No. 4) be taken as
unity, and the other results reduced by it, when the table will
stand thus :

Table No. 5. reduced (from No. 4).

1st, copper equal to the zinc, gave, loss 1*0

2nd, twice the zinc, gave, loss ... 1*3

3rd, 4 times the zinc, gave, loss 16

4th, — . 8 times the zinc, gave, loss 2*1

5th, 12 times the zinc, gave, loss 3*6

6th, 16 times the zinc, gave, loss 4*6

7th, 20 times the zinc, gave, loss 3*7

8th, — . 24 times the zinc, gave, loss 3*7

Third Series. Vol. 11. No. 64. July 1837. L

nearly,

74 Mr. Binks on the Laws of Action of Voltaic Electricity,

By which it is made apparent that (compared with equal
plates) the effectiveness of any simple voltaic circle is increased
about 4^ times, by having the surface of copper 16 times
greater than the zinc.

But these results may not follow from the operation of an
invariable law, but of one peculiar to the prevailing condi-
tions of the arrangements herein employed ; as the activity of
its action may evolve as much hydrogen as needs so large a
surface to permit its formation with the greatest facility. But
let the activity of the generating agents be lessened, and will it
then need a surface equal to lb*, comparatively? to induce the
greatest effect? Now this rapidity of action may be lessened
by either removing the elementary plates further apart, or by
more largely diluting the exciting acid. And to determine the
influence of such changes, first, the plates were separated from
the distance of one inch to that of two inches, and the experi-
ments, with coppers of various surfaces, repeated, when, al-
though less zinc was expended in the aggregate during an
equal time, yet the greatest loss in any given period occurred
when the copper was 16 times larger than the zinc.

The plates being restored to their usual distances from one
another, the experiments were repeated twice, with acid solu-
tions, formed, first, by the mixture of 2^ parts acid and 100
water, and, secondly, of 9 parts acid and 100 water, when
the results were so nearly the same as those registered in the
above table, as to indicate, without doubt, the operation in
each instance of the same law, and to make it unquestionable
that it was general, within at least the range of those circum-
stances here brought into operation. For though, in the one
case, the quantity of action was less and in the other more than
in the standard tables, yet the maximum effect, in the respect-
ive sets of trials, was always exhibited when the copper was 16
times greater than the zinc.

An important point of inquiry now presents itself to be de-
cided, namely, whether it is by the extension of surface merely
that this advantage is gained, or whether it be due to the
greater mass of conducting copper thus brought into action,
or to the united influence of both. Experiments were made
to determine this point, from which this one may be selected :

An amalgamated zinc plate, measuring 4- square inches, was
employed in the first instance, along with a sheet of thin cop-
per, weighing a few ounces, and having a surface of 16 square
inches, when the result in zinc lost was 6~JT) grains. Then the
same zinc plate was connected with a solid prism of copper, of
the same external dimensions as the sheet just used, but weigh-
ing about two pounds, when the zinc lost, during an equal time,

and on the Construction of Voltaic Batteries. 75

72 grs. And when the solid mass was extended in its sur-
face, or (which is the same thing) when two pounds' weight
of sheet copper was joined with the same zinc plate, the
amount of action upon it was found to be increased from 7*2
to 16*5 grains; the former loss resulting from the influence
of a surface equal to ] 6 square inches, and the latter from
that of about 170 square inches; showing distinctly that it is
to extended surface only that this effect is to be ascribed, and
that it is in no respect due to the influence of the better con-
ducting power of the metal as a mass.

It is remarkable that in this law of action to which the fore-
going experiments have led me, but which is widely different
from any I had anticipated, we have an exact correspondence
with the specific gravities of the two gases involved in its ope-
ration. The specific gravities of oxygen and hydrogen are as
lb' to 1 ; and it is when this proportion between the two sur-
faces, upon which they respectively appear, is preserved, that
any voltaic combination seems to be placed in the best posi-
tion for the exercise of its full power. This correspondence
may therefore be presumed to be something more than a
mere coincidence.

Two other points, bearing more immediately upon the ap-
plication of these principles to the construction of the batter}',
remain to be decided. In the preceding experiments the cop-
per plate did not extend over, nor was it placed opposite to,
both surfaces of the generating zinc, as in the arrangement
adopted by Wollaston; but was placed opposite one face only
of it. It therefore occurs, as a part of the inquiry, whether
the action upon the zinc took place upon or belonged to that
surface only which was next to the conducting copper one, or
whether it was due to an influence extending over the whole
surface of the zinc immersed : whether, if another copper plate,
of the determined dimensions, were placed over against the
other surface of the zinc, we should gain a further and double
accession of power ?

Experiment. 1st. A zinc plate, with copper equal to 16,
placed on one side only, lost 12*0 grains. 2nd. The same,
with two copper plates, one on each side, and presenting, in
full, a surface comparatively of 32*, lost 12*3 grains in an
equal time.

There is, therefore, nothing to be gained by apportioning
both surfaces of the generating plate, provided the copper plate
on the one side be in the full proportion.

Again : Is the influence of the copper plate due to the exer-
cise of one, or of both its surfaces ? Do they both operate or
only that one opposite the zinc ?

L2

76 Mr. Binks on the Laws of Action of Voltaic Electricity,

Experiment. 1st. A copper plate, clean on both its sides,
was first put in operation ; when its associated zinc plate lost
12*2 grs. 2nd. One side of the copper plate was now covered
with wax and the connected zinc plate then lost 10*5 grains ;
showing, as you have remarked before*, that the outer sur-
face is, to a slight extent, engaged in the operation ; but not
so importantly as to make it of much regard in the construc-
tion of voltaic batteries.

First Investigation. Part II.

To determine the influence and its extent, of increasing the
size of the zinc plate beyond that of the copper one.

In some of the galvanic batteries recently constructed the
form is such that each successive couple is greater or smaller
by a certain ratio than its adjoining one ; and the arrange-
ment of such a combination may be, either that a zinc plate
is operating along with a larger copper plate; or that the zinc
plate is the superior in size compared with the copper one
immersed with it and operating in the same mass of liquid.
Besides this, it is a matter of common remark, that the power
of such arrangements is augmented by the employment of
zinc plates the larger of the two.

Having already determined the kind and amount of in-
fluence exercised by copper plates of various comparative sizes,
it follows to determine in what way the zinc or generating
surfaces will operate when made the greater of the two ; the
ultimate object of the inquiry being to test the alleged supe-
riority of tnose forms of voltaic batteries which permit of such
an arrangement being brought into action.

The experiments were conducted in a manner similar to
the preceding ones, except that, in as much as the zinc plates
here used were too large to admit of their being weighed with
sufficient nicety, the amount of action was estimated, not by
the loss of metal, but by the measure of evolved hydrogen.

First the two plates were of equal size, then the zinc was
increased, the original copper plate being used throughout.

Table No. 6.

1st. Copper and zinc, when equal, gave hyd. = 08 cubic inches.

2nd. with zinc, twice its size, — hyd. = 1'6

3rd. zinc, four times, — hyd. = 2'4

4th. zinc, six times — hyd. = 2*5

5th. zinc, eight times, — hyd. = 2*2

(Jth. zinc, twelve times, — h)d. = 2*2

7th. zinc, sixteen times, — hyd. = 2-2

8th. zinc, twenty times,' — hyd. = 2*2

IHh. zinc, twenty-four times, hyd. = 2*2

♦ Philosophical Transactions, 1836, p 113, 116.

and on the Construction of Voltaic Batteries. 77

Then, taking the results of equal plates (or the first line of
the above) as unity, this table reduced stands thus :
Table No. 7- (No. 6. reduced.)

1st. Equal sizes = 1*0

2nd. Zinc increased by 2 = 2 0

3rd. by 4 = 30

4th. by 6 = 31

5th. by 8 = 27 V nearly.

6th. by 12 = 27

7th. by 16 = 27

8th. by 20 = 27

9th. by 24 = 27 J

Showing by the first (No. 6.) that the greatest effect fol-
lows upon the employment of a zinc plate six or seven time9
larger than the copper ; and by the second table (No. 7.) that
the absolute amount of action gained (when that is at its maxi-
mum) is about three times beyond that produced when the
plates are equal.

To sum up the results brought out by the foregoing investi-
gation, it appears that both the zinc and copper plates exer-
cise a definite influence when either is made the larger in any
voltaic arrangement ; but that that influence is different in de-
gree in each case ; that when the zinc is the larger, its full
effect is obtained when it is about seven times the greater, and
the absolute amount of that effect is three compared with
equal plates as one : but that when the copper is the greater
in the arrangement, then its full effect is not reached till it
measure sixteen times greater than the zinc, and the total
absolute amount gained, over equal plates, is four and a half.

Having ascertained these facts, I now proceeded to trace
their influence in compound arrangements, as well as in the
simple elementary ones to which the experiments had hitherto
been restricted. Accordingly I prepared three batteries, con-
sisting of a series of ten couples each.

The first (A) had the zinc and copper plates of equal size,
and each plate presented a surface of four square inches to
the action of the acid.

The second (B) had zinc plates of the same dimensions as
those of A, but were connected to copper ones sixteen times
larger, that is, the zinc were each four and the cor/per sixty -
four square inches in surface.

The third battery was furnished with copper plates the same
size as those in A ; but the zinc ones were seven times larger,
that is, the copper ones were four square inches each, and the
zinc ones twenty-eight.

These batteries being each excited by an acid mixture of
the same strength, and their action continued through equal

78 Mr. Binks on the Laws of Action of Voltaic Electricity,

times, gave the following results, as indicated by an interposed
voltameter:

A, in 30 minutes gave in mixed gases 1*2 cubic inch.

B, in do. do. 6*8 cubic inches.

C, in do. do. V5

Demonstrating that the laws just proved to operate in the
case of single arrangements, operate also in that of compound
ones. But the advantages gained in B and C are greater even
than had been anticipated by those laws, a circumstance which
is explained in a subsequent investigation (No. 3.), when it will
be proved that the above results are in exact accordance with
those found to obtain in the case of the single arrangements
already treated of.

There is one fact brought out by the above experiments to
which I should wish to attract your attention, merely pre-
mising, that inasmuch as the coincidence between it and some
other facts, which I suspect may be detected, may or may not
be purely of an accidental character, I should wish to be un-
derstood as attaching no importance to it beyond that which
would make me bear it in mind till our further acquaintance
with the origin and operations of this still mysterious agent
may contribute to its proper explanation. The fact I allude
to is this: in Table, No. 6, it is shown that it is when the sur-
face of the zinc plate becomes equal to about seven (the cop-
per being one) that the full voltaic effect is produced : why is
it, that the action regularly increases in amount till the re-
spective surfaces reach this relative proportion, and that it
then ceases to be augmented under any further addition
whatever ?

Second Investigation.

An inquiry into the comparative action of surfaces of dif-
ferent extent; that is, whether the action of any voltaic com-
bination increases directly as the surface increases, or in some
other ratio.

Depending upon the accuracy of that law (which has been
generally admitted), that if the surfaces of the plates be increa-
sed, the resulting action will be increased in the same ratio, I
had been led into some strangely anomalous results in my ex-
periments, which could be accounted for only on the supposi-
tion that this law might possibly be incorrect. I had found
little reason to dispute its accuracy when the examinations
were restricted to plates varying from one square inch to four;
but when carried beyond these sizes, its fallacy became stri-
kingly apparent.

To examine into this, I prepared several simple arrange-

and on the Construction of Voltaic Batteries. 79

merits composed of zinc and copper in the proportions of one
to sixteen. The sizes of the zinc plates are stated in the sub-
joined table. At the end of each time of immersion the acid
mixture was renewed, &c. ; when it appeared that,
(Table No. 8.)
1st. A zinc plate measuring one square inch, lost (in 30 min.) 5*0 grs.

2nd. A zinc do. . two — inches, lost ( do. ) 9-9

3rd. A zinc do. four — — lost ( — ) 19-0

4th. A zinc do. eight — — lost ( — ) 29-2

5th. A zinc do. sixteen — lost ( — ) 40-0

Now, had the formerly admitted law of increase been true,
we should have had the last plate in the table exhibiting a
result of action equal to sixteen times greater than the first
one; since its surface is sixteen times larger. But the first
loses five grains, and the last 40 ; whereas, had this law been
correct, it should have lost 80 grains, or 5 x 16 ; but the re-
sult found by actual experiment is only one half or 40 grs.

But was this result the effect of any peculiar conditions at-
tending the experiments ? I varied the form of the experi-
ments in every possible way, but with still the same general
results. For instance, the zinc and copper plates were con-
nected by wires of thicknesses proportional to their theoretical
values; when the results were the same: or the conducting
wires were made to extend around the whole outer edge of
the generating plates and thence to the copper ones, or one
entire side of the zinc was covered by a conducting plate of
copper, (itself and the joinings, both id this and the last case,
being carefully protected from the acid by varnish,) yet by
every modification the same general results were brought out.
The increase, therefore, is not as the surface, but in some
other ratio yet to be determined.

Third Investigation.

To determine the kind of influence exercised by single
voltaic arrangements, one upon another, when used in con-
nection, whether they be of equal or of unequal sizes.

It is but to be expected, a priori, that arrangements so si-
tuated and connected as in the following experiments, will
exhibit the operation of laws, not of an arbitrary but of a de-
finite and unchanging kind. The great discovery of Faraday
leads necessarily to this expectation ; and every correct ex-
periment will unquestionably confirm his law, and exhibit its
extended influence. These experiments, however, have no
pretension beyond that of reaching to such a degree of accu-
racy as shall be subservient to their avowed object : such a
degree of minuteness only is aimed at as shall prove of practi-
cal value to the ultimate object of the whole inquiry, namely,
the construction of the battery.

SO Mr. Binks on the Laws of Action of Voltaic Electricity,

Let a single voltaic arrangement be immersed in acid of a
certain strength, and dining a certain length of time, and its
voltaic action determined by the quantity of zinc lost, or of
hydrogen evolved. Let another such arrangement (either of
equal or of unequal size) be tested in the same manner; and
then (having thus determined the amount of action peculiar
to each when acting separately) let them be connected as a
compound arrangement; that is, let the zinc of each one ar-
rangement be joined by a wire to the copper of the other, and
then the amount of action determined when thus operating
upon one another.

These experiments were so contrived that the distance be-
tween the elementary zinc and copper plates, in any arrange-
ment, was always the same; and also that the wires connect-
ing them (whether when used separately or in connection)
were always of the same length, in order to avoid those dif-
ferences in the results which would have arisen had these pre-
cautions not been strictly observed.

I shall select the following as a preliminary example of
such a mode of analysis :

A plate of zinc (in A) and a plate of copper of the same
size, joined together as a simple circle, were immersed in an
acid mixture during 30 minutes, and gave off hydrogen equal
to 3/jj cubic inches. Another such arrangement (in B), but of
larger size, was treated in the same way and yielded 16 cubic
inches of hydrogen.

These same arrangements were now connected as repre-

and on the Construction of Voltaic Batteries. 81

sented in C and D; and (every circumstance being preserved
the same as before) C yielded 4*4 cubic inches of hydrogen,
and D precisely the same, viz. 4*4? cubic inches.

When separated. When joined.
A was equal to 3*2 cub. in. C was equal to 4*4 cub. in.
B 16*0 D 4-4 cub. in.

Total ... 19-2 Total ... 8*8

From which it appears that when mutually operating the
action is distributed equally over both; but that its total
amount is reduced by about one half from that which took
place when the arrangements were distinct.

This example will serve to indicate the kind and object of
the following experiments, with which I will now proceed
systematically.

A. To determine the mutual influence exercised by arrange-
ments when they are of the same size.

I prepared forty-eight arrangements, formed each of plates
of zinc and copper of the same size, each plate measuring four
square inches. I first took a number of these arrangements,
and immersed them separately, and found, by an average, the
loss that each sustained in a certain length of time. This
average I found to be 5*7 grains of zinc expended ; and it is
accordingly placed first in the annexed table, as a standard of
comparison.

I now took two of these arrangements and connected them
as in the above example, and found the result of their action.
Then four such were connected, and the results ascertained
in the same way, as were also the results of combinations of
8, 16, 32, &c. as shown in the table.

Table No. 9.
1st. Average loss of single arr
2nd. Two arrangements, gave
3rd. Four do.
4th. Eight do.
5th. Sixteen do.
6th. Thirty-two do.
7th. Forty do.
8th. Forty-eight do.

Now it will be seen by this table that the amount of action in>
combined arrangements is less than the action in single ones.
For instance, the action of two such joined is about one third
less than takes place when they are used separately. This
was unexpected ; but not more so than some other results that
follow. I have had the greatest difficulty in deciding upon
the precise amount of the difference between the action of

Third Series. Vol. 11. No. 65. Suppl. July 1837. M

igement =

57 grains.

loss =

39 each.

loss =

3-8 each.

1oj»s =

3-8 each.

loss =

34 each.

loss =

3-6 each.

loss =

3-8 each.

loss =

2*7 each.

82 Mr. Binks on the Laws of Action of Voltaic Electricity,

single and double arrangements. Sometimes the action in the
latter case has been reduced one half, sometimes one fifth,
but more frequently one third ; and the cause of this variable-
ness I have been wholly unable to detect. But this uncer-
tainty does not attach to those cases in which more than two
arrangements are operating, as will be made evident as these
experiments proceed. It will also be seen by this table, that
although the number of the series was extended to 48, yet the
action in any one of the combined series never became equal
in amount to that which took place when they were used se-
parately.

B. To determine the mutual influence exercised by arrange-
ments when they are of different sizes compared with one
another.

As I have already given an example of this kind of exami-
nation above, I need not further explain the manner of conduct-
ing it, but will exhibit the results at one view in the subjoined
Table No. 10.
1st, Arrangements of equal size.
When separate. When joined.

A gave hyd. ... 0'8 cubic inch.
B gave hyd. ... 0*8

Total

1-6

A gave hyd. ... 0*4 cubic inch.
B gave hyd. ... 0*4

Total 0-8

2nd, With the arrangements differing in size in the propor-
tion of 1 to 3.

C gave hyd.
D gave hyd.

2 4 cubic inch.
74

Total 9-8

C gave hyd.
D gave hyd.

Total

2*4 cubic inches.
2-4

4-8

3rd, With the arrangements differing in size in the pro-
portion of 1 to 5.

E gave hyd.
F gave hyd.

3*2 cubic inches.
16-0

Total 19-2

E gave hyd.
F gave hyd.

4*4 cubic inches.
4-4

Total 8-8

4th, With the arrangements differing in size in the proportion

of 1 to 9.

G gave hyd. ... 1-4 cubic inches.
H gave hyd. ... 12-0

Total

134

G gave hyd. ... 2*6 cubic inches.
H gave hyd. ... 3'b*

Total 62

5th, With the arrangements differing in the proportion of

1 to 16.

I gave hyd.
K gave hyd.

08 cubic inches.
12-8

Total J 3-6

I gave hyd. ... 1*6 cubic inches.
K gave hyd. ... 2-6

Total 4-2

and on the Construction of Voltaic Batteries. 83

It will be observed here that in the 4th and 5th instances,
in which there was a great disparity between the sizes of the
two arrangements, the results of their combined action were
not divided equally between the two, but appeared greater
in that vessel in which the greater zinc plate was acting. But
when we come to those experiments in which the arrange-
ments are fitted to copper plates in the relative proportion of
16 to 1 of zinc, it will be seen that the results are different;
that then in every instance the action is equally distributed
through any combined series.

I now tried a combination of three arrangements, in which

Table No. 11.
When separate. When joined.

A gave hyd. ... 2* cubic inches.

B gave hyd. ... 9*

C gave hyd. ... 18*

Total 29-

A gave hyd. ... 3*4 cubic inches.

B gave hyd. ... 3 4

C gave hyd. ... 3*4

Total 10-2

These experiments appear to be interesting in other respects
than as they bear upon the object for which they were ex-
pressly made. But confining myself to the immediate purpose
I proceed to show :

C. The mutual influence of arrangements when they were
equal in size compared with one another, but in which the
elementary zinc and copper plates are in the proportion of
1 to 16.

Three arrangements were prepared exactly alike.

Table No. 12.

When separate. When joined.

No. 1, lost zinc ... 19-9 grains.

No. 2, lost zinc ... 25*0 grains.

No. 3, lost zinc ... 237 grains.

Total 68-6

No. 1, lost ... 28-8 grains.

No. 2, lost ... 29 3 grains.

No. 3, lost ... 28*5grain§.

Total 866

Showing by the results in A that when similar arrange-
ments were connected with copper plates of the same size as
the zinc, their combined action was remarkably reduced; but
when the copper piates were in the proportion of the last
experiment in C, then, instead of a great reduction in the
amount of their action when combined, compared with
what it was when they were separate, we find that their action
is as remarkably increased: for by Table, No. 9, (in which
the copper and zinc plates are equal) we find a reduction of
about one third to take place on combination, and in this last
investigation, C, we find as remarkable an increase.

D. To determine the influence exercised in those cases in

M2

84 Mr. Binks on the Laws of Action of Voltaic Electricity,

which the elementary plates are in the proportions last observed
(in C), but in which the arrangements themselves are un-
equal.

Three arrangements were employed.

Table No. 13.
When separate. When joined.

1st, lost zinc ... 5*0 grains.

2nd, lost zinc ... 19*0 grains.

3rd, lost zinc ... 40*0 grains.

Total 64-0

1st, lost zinc 13*1 grains.
2nd, lost zinc 13*2 grains.
3rd, lost zinc 132 grains.

Total 39-5

Showing a remarkable decrease in action (as has invariably
occurred) to follow the employment of voltaic arrangements
of unequal sizes when compared one with another in the same
series.

I should wish it to be particularly remarked here, that in
this last experiment (D) and in the one preceding it (C) the
total surfaces of the metals in operation were exactly of the
same dimensions.

The zinc plates in C measured each 7 square inchesl , . i
The copper plates do. do. 112 square inches J

being multiplied by 3 (the number used) give zinc equal to
21 square inches, and copper equal to 336 square inches in
the whole. And in D the 1st arrangement was composed of
1 square inch zinc and 16 copper; the 2nd, of 4 square inches
zinc and 64 copper; the 3rd, of 16 square inches zinc and
256 copper, making a total, the same exactly as in C,
namely, of 21 square inches of zinc, and 336 square inches of
copper. And it has been shown that when these two sets of
arrangements were put in operation, the one (C) lost 86*6 grs.,
and the other (D) lost only 39*5 grs.

The conclusion to which these experiments obviously lead
is this; that there is no advantage to be gained by using the
elementary combinations of any voltaic battery of an unequal
size when compared with one another; but on the other hand,
that such a form of battery is remarkably defective when com-
pared with another, having an equal extent of metallic surface.,
but in which the elementary couples are of uniform sizt
throughout the series.

To verify the conclusion here advanced I prepared thret
small batteries, and tested their comparative efficacy by theii
power of decomposing water.

Each battery consisted of a combination of six elementar)
couples, and the total surface of zinc in each battery was St
square inches and of copper 1008 square inches.

and on the Construction of Voltaic Batteries. 85

The first, or A, had its elementary couples of equal size;
each of its zinc plates measured 10£ square inches, and each
of its copper ones 168 square inches.

The second, or B, had its couples of unequal sizes, as seen
in this table.

1st couple had zinc= 1 square inch, and copper = 16 square inches.

2nd zinc = 2 square inches, and copper = 32 •

3rJ zinc = 4 and copper = 64 ■

4th zinc = 8 and copper = 128

5th zinc =16 and copper = 256

6th zinc = 32 and copper = 512

Total 63 square inches. 1008 square inches.

The third battery, or C, had its couples also unequal^ but
increasing from the first one by a different progression. I
need only write out the dimensions of the zinc, each corre-
sponding copper being sixteen times larger.

1st couple had zinc = 8 square inches "] copper

2nd zinc = 9

3rd zinc =10

4th zinc = 11

5th zinc =12

6th zinc = 13

Total 63 1008 ditto.

The electricity developed by each of these batteries was
passed in succession through a voltameter holding acidulated
water, during times of 30 minutes each ; when

A yielded of mixed gases, 1*3 cub. inch,
B yielded do. do. 0*7 cub. inch,
C yielded do. do. 1*1 cub. inch,
results which verify the conclusion drawn from the preceding
experiments, and which prove besides that even when the dif-
ference in the sizes of the component circles of the battery is as
trifling as in C, their inequality is attended too with a marked
inferiority of action.

Since the above experiments were made I have contrived
an apparatus by which such kinds of experiments, and many
others of great importance to the science, may be conducted
with the greatest possible precision and certainty. Its prin-
ciple depends essentially on the substitution, in the place of
amalgamated plates, of ajluid amalgam, formed by the union
of 20 parts by weight of mercury and 1 of zinc. But as
this paper has already exceeded any reasonable limits, I will
not trespass on your patience with any description of its form
or operation beyond that of merely stating that it appears
to me to be admirably calculated for deciding many of the

86 Mr. Binks on the Laws of Action of Voltaic Electricity,

controverted points in the laws of this science ; and one of
such to which I shall attempt to apply it will be to determine
the real relation that subsists between the deflexions of the
magnetic needle and the quantity of zinc expended in pro-
ducing those deflexions, or, which is the same thing, between
the deflexions and the quantity of electricity which produces
them.

Fourth Investigation,
Up to this step in the inquiry I have restricted myself to
the use of diluted sulphuric acid as the exciting agent. The
foregoing facts, or, it may be, laws of action, have therefore
been determined for this one condition only out of the many
under which the electrical action may be developed. The
phenomena attendant upon this mode of excitation are, pri-
marily, the decomposition of the water, the combination of its
oxygen with the zinc, and the liberation of its hydrogen as
hydrogen, that is, in its gaseous state, upon the surface of the
conducting metal. Now, in the results of the first investiga-
tion we perceive that there exists a coincidence between the
relative bulks (compared with equal weights) of oxygen and
hydrogen gases and the relative surfaces of the two metallic
plates ot any voltaic circle in which the maximum electrical
effect takes place. This fact, which I speak of as a mere co-
incidence, should not be overlooked. It may indicate a priori
that the same relative proportions in the two metals which
have been determined for this one instance may be needed in
every instance in which water is decomposed and its hydrogen
liberated in the form of gas. But we have no reason to anti-
cipate a priori that if any other substance than hydrogen be
yielded at the conducting plate, we shall still, to produce the
maximum effect, have to preserve the same proportions of the
two metals as have been determined for that case. Suppose the
operations within the cells of any battery to be so modified that,
although water shall still be the substance decomposed, yet
intead of the production of hydrogen we have the deposition
of metallic copper, or the reformation of water, or the forma-
tion of some other body physically different from hydrogen
as the results of the operations, what proportions of the two
metals will then be needed to ensure the maximum effect?
Such modifying agents are readily obtained. A proper mix-
ture of the nitric and sulphuric acids with water will lead, not
to the production of gaseous hydrogen, but to the formation
of water and ammonia within the cells of the battery ; and the
solution of sulphate of copper to the deposition of metallic
copper and the reformation of water. I will at this time exa-
mine but the latter of these two, and endeavour to determine

and on the Construction of Voltaic Batteries, 87

what proportions should be observed between the two metals
when the copper is immersed in a solution of its sulphate.

The experiments were conducted as in the first investiga-
tion. The zinc was immersed in dilute sulphuric acid, formed
of 4| acid to 100 water, and confined in a membranous bag,
the copper solution surrounding it.

The zinc plate measured 2 square inches ; it, as well as the
acid and solution, was renewed each time of immersion. The
first copper plate was equal in size to the zinc, then the copper
plates were used of larger sizes in succession, as seen in the
table.

Table No. 14.
1st, zinc with copper, equal, in 30 minutes lost... 6*0 grains

2nd, twice its size do. lost... 7*0 —

3rd, 4 times do. do. lost... 9*0 —

4th, — | 8 times do. do. lost... 13*3 —

5th, 16 times do. do. lost... 11*5 —

6th, 20 times do. do. lost... 10*0 —

I am wholly unable to account for the deficiency in action
observed in the fifth and sixth instances, when compared with
the fourth, since the conditions of the experiments were in
each instance precisely alike, save of course the size of the
experimental copper plates.

This table, therefore, indicates that it is when the copper
plate is about eight times larger than the zinc one, that the
greatest effect ensues in the case in which sulphate of copper
surrounds the conducting plate, and the voltaic action is ac-
companied by the deposition of metallic copper and the refor-
mation of water.

These trials were varied twice ; first by using a stronger
acid solution to act upon the zinc ; and secondly, by using
merely water for the same purpose, when the results exhibited
the operation of the same law, namely, that the maximum ef-
fect followed upon the employment of the copper plate about
eight times larger than the zinc.

For reasons already sufficiently adverted to, I have con-
fined my examinations to some of the cases most commonly
met with in the ordinary employment of the battery. But
were this kind of examination extended into every case of
voltaic action in which different bodies, that is, bodies physic-
ally different from one another, are the result of the opera-
tions within the cells of the battery, I have no doubt that a
specific and different proportion between the sizes of the two
constituent metals would be found to be needed for each case,
in order to obtain the maximum effect ; and that the relations
which would be thus discovered would be at once curious

88 Mr. Binks on the Laws of Action of Voltaic Electricity.

and of the utmost importance to the general theory of the
science.

My own experiments have been extended to the examina-
tion of only two of such cases; namely, first to that in which
sulphuric acid is the exciting agent, and gaseous hydrogen the
product upon the surface of the conducting metal ; and se-
condly, to that in which sulphuric acid (derived either from
the dissolved sulphate, or from free acid previously added) is
still the exciting agent, but in which metallic copper is the
product appearing at the conducting plate; these two having
been selected, from the highly distinctive character of their re-
spective phenomena.

Recurring to the former of these investigations, I should
wish, before concluding this paper, to attract your attention
to a fact which has been invariably presented in their course,
when the arrangement of any voltaic battery has been such
that the whole of its evolved hydrogen could be collected, and
the total quantity of zinc employed in its formation be also
ascertained.

If a single voltaic arrangement be employed to generate
hydrogen, an exact correspondence will be perceived between
the quantity of zinc expended and the volume of hydrogen
evolved, and their theoretical proportions as determined by
calculation. The same regularity will be maintained whether
plain or amalgamated plates of zinc be employed in the ar-
rangement, and also whether single, or double, or treble ar-
rangements, &c, connected, be brought into operation with
this view ; up to a certain number of such, if the hydrogen
and zinc be compared, there will be found to be a perfect
agreement between their quantities and those anticipated by
theory. But if the number of voltaic pairs be so many that
the battery possesses energy enough to decompose water when
submitted to it in the usual way, then this exact correspond-
ence between the proportions of the hydrogen and the zinc
will be no longer maintained ; but it will be found that the
total quantity of zinc expended will be greater, by about one
third, than is needed to generate the quantity of hydrogen
actually evolved.

As 1 intend to enter upon a more minute examination of
this phenomenon, I will, at this moment, offer but a single
example of it, which is sufficiently marked and accurate to in-
dicate its real nature.

A small battery of 16 equal pairs, arranged as the couronnr
des lasses, was put in operation ; and so combined that the hy-
drogen from each cell could be collected and each zinc plate

Proceedings of Learned Societies. 89

weighed at the end of a certain time. Each vessel was found
to contain as nearly as possible the same measure of hydro-
gen ; and a like equality of action upon the zinc had taken
place throughout the series.

The total quantity of hydrogen was 60*6 cubic inches; the
total quantity of zinc expended was 74*0 grains.

Now, I had previously determined that 34*5 grains of the
zinc I employed were needed to produce an equivalent of hydro-
gen ; and taking the weight of 100 cubic inches to be 2*1318
grains, we have the measure of an equivalent of hydrogen
equal to 46*9 cubic inches. Therefore, the 74*0 grains of
zinc here consumed should have yielded 100*5 cubic inches of
the gas, but they actually yielded only 60*6 cubic inches.

Whether or not a voltameter were interposed the results
were similar : invariably the same want of correspondence ap-
peared between the loss of the zinc and the volume of evolved
gas and their relative quantities as found by theory ; and the
amount of this difference was always somewhat similar to that
exhibited in the above experiment.

The operations within the cells of the battery admit of easy
analysis, and this phenomenon also admits perhaps of an easy
explanation; but the fact it seems to indicate, viz. that a certain
portion (and that about one third of the whole) of the hydro-
gen subserves some purpose closely connected with the power
of the battery to decompose water, appears to be of so much
importance as to make it deserving of a more careful exami-
nation. I remain, dear Sir,

Your obliged friend and pupil,
Newington, Edinburgh, March 28, 1837. C. BiNKS.

XV. Proceedings of Learned Societies.

ROYAL SOCIETY.
[Continued from vol. x. p. 382.]

a -i g A paper was in part read, entitled, " Further Obser-

V /*■ vations on Voltaic Combinations ; in a letter ad-

dressed to Michael Faraday, Esq., D.C.L. F.R.S., Fullerian Pro-
fessor of Chemistry in the Royal Institution, &c. &c." By John
Frederick Daniel), Esq., F.R.S., Professor of Chemistry in King's
College, London.*

April 13. — The reading of Professor Daniell's paper was resumed
and concluded.

In the course of an inquiry into the effects of changes of tempe-
rature upon voltaic action, the author was led to observe some curious

* Abstracts of Prof. Daniell's former papers have been given in Lond.
and Edinb. Phil. Mag., vol. viii. p. 421 ; vol. ix. p. 376.

Third Series. Vol. 11. No. 65, Supplement, July 1837. N

90 Royal Society.

disturbances and divisions of the electric current produced by the
battery, arising from secondary combinations j the results of which
observations form the subject of the present paper. He found that
the resistance to the passage of the current was diminished by dis-
solving the sulphate of copper which was in contact with the copper
in the standard sulphuric acid, instead of water. The increased
effect of the current, as measured by the voltameter, was farther
augmented by the heat evolved during the mixture ; and wishing
to study the influence of temperature in modifying these effects,
the author placed the cells of the battery in a tub, filled with hot
water. On charging the cells with a solution of muriate of am-
monia in the interior, and aqueous solution of sulphate of copper in
the exterior compartment, he observed that a portion of the current
is discharged by the water in which the apparatus is immersed ;
its passage being indicated by the disengagement of gas betwixt
the adjacent cells; in which case, one of the zinc rods is thrown
out of action, and the copper of that cell acts merely as an electrode
to the antecedent zinc. A saturated solution of common salt was
next placed in contact with the zinc, while the exterior compart-
ments of the cells were filled with a saturated aqueous solution of
sulphate of copper } but the effects were much diminished. It thus
appeared that the substitution of solutions of the muriates for dilute
sulphuric acid was in every way disadvantageous ; and it was more-
over found that, when the circuit was broken, the copper became
seriously injured by their action, and by the formation of a sub-
muriate of that metal.

Finding that the membranous tubes were unable to resist the
action of the acid under the influence of high temperatures, the au-
thor substituted for them tubes of porous earthenware, of the same
texture as that of which wine-coolers are commonly made, closed
at their lower ends, and of the same height as the copper cells.
The bottoms of the latter were fitted with sockets, for the reception
of the tubes, and for confining them in their proper places ; the .
perforated copper plates, or colanders, which held the solid
sulphate of copper, passing over their upper ends. The tubes can
be easily removed, and instantly replaced ; and the facility of
emptying and refilling them renders the addition of siphon-tubes
unnecessary, except in very particular circumstances. A cir-
cular steam- vessel of tin plate was then provided, around which
the cells could be placed upon blocks of wood, and closed in with
a cover, containing a socket, which could, at pleasure, be connected
with the steam pipe of a boiler. Two other sockets were also con-
veniently placed, provided with cork stoppers, through which the
electrodes of the battery could pass, when the proper connexions
were made. By using this apparatus the author determined that the
increase of effect consequent on an augmentation of temperature is
but in a slight degree dependent on an increase of conducting power
in the electrolyte, but arises principally from its increased energy of
affinity, producing a greater electromotive force.

In heating the battery by the steamer, it frequently happened that,

Royal Society. 91

when the thermometer had nearly reached the boiling point, and
the action of the battery was at its maximum, a sudden cessation of
its action would take place ; and this suspension of power would
continue for hours, provided the high temperature were maintained.
On turning off the steam, and quickly cooling the apparatus, the
action would return as suddenly as it had ceased, though, generally,
not to the full amount. On closely examining the voltameter, on
these occasions, it was found that the current was not wholly stopped ;
but that there existed a small residual current. This residual cur-
rent was observed to be often directed in a course opposite to that
which had before prevailed ; and it was, in that case, the excess of
a counter current, arising from a force which was acting in the
contrary direction. The author found that variable currents might
be produced, under ordinary circumstances, from the separate single
cells of the battery when the whole series is connected by short
wires. He proved by a series of experiments that the deoxidation
of the oxide of copper by the hydrogen is not the exciting cause of
the secondary currents j but that when the course of the main cur-
rent of the battery is obstructed by causing it to pass through the
long wire ofa galvanometer, or througbthe electrolyte of a voltameter,
the course of the secondary current from each separate cell is always
normal, or in the same direction : when, on the other hand, the
battery-current is allowed to flow with the least possible resistance,
as by completing the main circuit by a short wire, the secondary
current of the separate cells is in the opposite direction. Hence
the resistance may be so adjusted as that the secondary current shall
altogether disappear, or alternate between the two directions.

The remainder of the paper is occupied with the detail of ex-
periments made with a view to ascertain the effects of different degrees
of resistance to the voltaic currents under a great variety of cir-
cumstances.

April 20. — A paper was read in part, entitled, " Observations
taken on the Western Coast of North America." By the late Mr.
Douglas j with a report on his paper ; by Major Edward Sabine,
R.A., F.R.S. Communicated by the Right Honourable Lord Glenelg,
one of His Majesty's Principal Secretaries of State, F.R.S., &c.

April 27. — The reading of Mr. Douglas and Major Sabine's pa-
per, was resumed and concluded.

In the report prefixed to this paper, Major Sabine states, that
Mr. Douglas was originally a gardener, and was, in the year 1833,
recommended by Sir William Jackson Hooker to the late Mr. Joseph
Sabine, who was then Secretary to the Horticultural Society of Lon-
don, as a fit person to be employed by the Society in selecting and
bringing to England a collection of plants from the United States
of America. Having accomplished this mission to the complete
satisfaction of his employers, he was next engaged on an expedition
having similar objects with the former, but embracing a much larger
field ; namely, the tract of country extending from California to
the highest latitude he might find it practicable to attain on the
western side Qt' the Rocky Mountains. Anxious to render to geo-

N2

.02 Hoy at Society.

graphical and physical science all the services in his power, and to
avail himself for that purpose of every opportunity which his
visiting these hitherto imperfectly explored regions might afford
him, he now endeavoured by diligent application to supply the
deficiencies of his previous education. During the three months
which preceded his departure from England, he studied with un-
remitting ardour and perseverance for no less than eighteen hours
each day ; and, conquering every difficulty, acquired a competent
knowledge of the principles of science, learned the uses of various
instruments, and made himself thoroughly master of the methods of
taking observations both at sea and on land.

The narrative proceeds to notice the arrival of Mr. Douglas in
America, the progress of his undertaking, the loss of his collections
and most of his books and papers, by the upsetting and dashing to
pieces of the canoe in which he attempted to pass the rapids, and,
lastly, his death in 1833, at Owhyhee, in the Sandwich Islands,
whither he had proceeded on his return to Europe.

The books which were preserved, and which have been received
by Major Sabine, consist of several volumes of Lunar, Chrono-
metrical, Magnetical, Meteorological and Geographical observa-
tions, together with a volume of field sketches. The geographical
observations of latitude and longitude refer to two distinct tracts
of country ; first, the Columbia river, and its tributaries ; and the
district to the westward of them : and, secondly, California. Mr.
Douglas very judiciously selected the junctions of rivers, and other
well characterized natural points, as stations for geographical de-
termination. The papers containing the details of his magnetical
inquiries comprise records of observation of the dip, and of the in-
tensity, at various stations both in North America and in the Sand-
wich Islands.

Analysis of the Roots of Equations. By the Rev. R. Murphy,
M.A. Communicated by John William Lubbock, Esq., F.R.S.

The object of this memoir is to show how the constituent parts
of the roots of algebraic equations may be determined by consi-
dering the conditions under which they vanish; and, conversely, to
show the signification of each such constituent part.

The following are the propositions on which the author's investi-
gations are founded.

1. In equations of degrees higher than the second, the same con-
stituent part of the root is found in several places, governed by the
same radical sign, but affected with the different corresponding
roots of unity as multipliers.

2. The root of every equation, of which the coefficients are ra-
tional, contains a rational part ; for the sum of the roots could not
otherwise be rational. This rational part, as such, is insusceptible
of change in the different roots of the same equation ; consequently
its value is the coefficient of the second term, with a changed sign,
divided by the number of roots, or index of the first term.

3. The supposed evanescence of any of the other constituent
parts, implies that a relation exists between the roots ; and if such

Royal Society. 95

a relation be expressed by equating a function of the roots to zero,
that constituent part will be the product of all such functions, and
a numerical factor.

4. The joint evanescence of various constituent parts, implies the
coexistence of various relations between the roots, and that an in-
terpretation may be given to each of the constituent parts, riveting
the expression of the root in the memory, and converting the solu-
tion of a problem into a condensed enunciation of various theorems.
The author exhibits the application of these principles to equations
of various degrees, beginning with quadratic and cubic, and pro-
ceeding to those involving higher powers.

"On the first changes in the Ova of the Mammifera, in conse-
quence of Impregnation ; and of the mode of origin of the Chorion."
By Thomas Wharton Jones, Esq. Communicated by Richard Owen,
Esq., F.R.S.

The author having, in a former paper*, described the structure
of the unimpregnated ovum of mammiferous animals, now proceeds
to investigate the changes which the ovum undergoes in consequence
of impregnation. In the rabbit, the first perceptible difference is the
addition of a thick gelatinous matter surrounding the parts of which
the ovum was composed in its original state, and apparently derived
from the ovaries. In the progress of development the vitellary
membrane gives way, as happens in the ova of the newt, and of
many of the oviparous animals. The gelatinous envelope acquired
in the ovary, and which is more especially circumscribed and defined
after impregnation, constitutes the only covering of the vascular
blastoderma, after the giving way of the vitellary membrane, and
afterwards forms the chorion, which in rodent animals, at a further
stage of development, presents itself under the form of a thin and
transparent membrane, very similar to the vitellary membrane of a
bird's egg, and situated immediately outside the non-vascular and
reflected layer of the umbilical or erythroid vesicle. The author
draws similar conclusions with regard to the development of the
human ovum.

The second part of the paper relates to the changes taking place
in thevitellus, the inferences concerning which are deduced chiefly
from observations of the development of the ova of batrachian
reptiles. The author concludes that the disappearance of the ger-
minal vesicle is prior to impregnation. In the newt, the vesicle,
at first imbedded in the substance of the yelk, gradually approaches
the surface, until its situation is immediately underneath the vitellary
membrane : its coat, havingnowbecome very soft, gives way, allowing
the contained fluid to be effused on the surrounding surface of the
yelk ; and the small depression in which the vesicle was lodged
now forms the cicatricula. The effused fluid gives a degree of con-
sistence to the matter composing the surface of the yelk, and thus
promotes the formation of the blastoderma. In the frog, the sur-
face of the yelk becomes every day more and more broken up, and
the resulting crystalline forms described by Prevost and Dumas be*
* See Lond. and Edinb. Phil. Mag., vol. vii. p. 209.

94? Royal Society*

come smaller and smaller, until the surface of the black blasto-
derma appears under a magnifying glass like shagreen. The bla-
stoderma, consisting of an aggregation of clear globules, different
from these of the rest of the yelk, is now fully formed, and has ex-
tended itself so as to close in the white spot. The change which
takes place in the yelk of the bird's egg appears to be limited to
the neighbourhood of the cicatricula.

May 4th. — On the adaptation of different modes of illuminating
Light-houses, as depending on their situations and the object con-
templated in their erection. By William Henry Barlow, Esq., in
a Letter addressed to Peter Barlow, Esq., F.R.S., and communi-
cated by him.

The letter of Mr. W. H. Barlow, addressed to his father, in which
the paper is contained, is dated Constantinople, March 14th, 1837,
and states that the experiments which he made with the Drummond
light, and other means of illuminating Light-houses, and of which
he now communicates the results, were undertaken at the request
of the Turkish Government, with the view of placing lights at the
entrance of the Bosphorus from the Black Sea *. The object of his
inquiry is to investigate the principles on which the illuminating
power, resulting from the employment of reflectors, and of lenses,
depends j and the most advantageous application of that power to
the purposes of Light-houses.

In discussing the relation which exists between the illuminating
power and the intensity of an artificial light, he observes that the
former is proportional to the quantity of light projected on a given
surface at a given distance ; and that the latter is dependent on
the quantity of light projected by a given area of the luminous
body on a given surface at a given distance. Hence the intensity
of a light multiplied into its surface is the measure of the illuminating
power, whether the light proceed from one or from several luminous
bodies : and the illuminating power is equal to that of a sphere of
light, whose intensity and apparent surface are equal to that of the
light itself at any given mean distance.

Within a certain limit of distance, the property of light which
produces the strongest impression on the eye, is its intensity ; but
when the light is so remote that the angle subtended by it at the
eye is very minute, as is generally the case in Light-houses, the
intensity of the impression made on the retina is proportional
only to the illuminating power. The mathematical investigations
of the author lead him to the conclusion that all reflectors and
lenses of the same diameter have the same illuminating power when
illuminated by the same lamp ; and that by diminishing the focal
distance, and intercepting more rays, the illuminating power is not
increased, but simply the divergence, and consequently the surface
or space over which it acts. The author then proceeds to inquire
into the comparative utility of lenses and reflectors, and arrives at

* In Lond. and Edinb. Phil. Mag., vol. viii. p. 238. will be found a letter
from Mr. W. H. Barlow, describing some of his preliminary trials at Con-
stantinople.

Royal Society. 95

the inference that the advantage gained by the employment of the
former does not arise from their superior perfection as optical in-
struments, but from their using the light more economically, in con-
sequence of their producing less divergence of the rays, both hori-
zontally and vertically, and illuminating a much smaller space in
the horizon. Rules are then deduced for the application of lenses
and reflectors in Light-houses, according to the particular situations
in which they are placed, and the purposes they are intended to
serve. With this view, the author divides Light-houses into three
classes : the first comprising Beacon or Warning Lights, placed in
order to prevent the approach of vessels, and which consequently
can never be nearer than three or four miles j the second being
Guiding or Leading Lights, placed to guide a vessel, and therefore
admitting of a very near approach ; and the third including those
which, according to the respective directions in which they are seen,
have both these duties to fulfil. In the first we require great il-
luminating power, and a long duration of the brightest period, with
a small angle of vertical divergence; in the second, less illumina-
ting power, but a larger angle of vertical divergence are requisite,
while the duration of the extreme brightness is of minor importance -,
and in the third, all these properties, namely, great illuminating
power, a long duration of the brightest period, and a large angle of
vertical divergence, are necessary.

May II. — A paper was in part read, entitled, "On the connexion
between the Phenomena of the absorption of Light and the Colours
of thin Plates." By Sir David Brewster, K.H., F.R.S.

The Society then adjourned over the Whitsun week, to meet again
on the 25th instant.

May 25. — Sir David Brewster's paper was resumed and con-
cluded.

The phenomena of the absorption of light by coloured media have
been regarded by modern philosophers as inexplicable on the theory
of the colours of thin plates, and therefore irreconcileable with the
Newtonian hypothesis, that the colours of natural bodies are depend-
ent on the same causes as the colours of thin plates. The discovery
by Mr. Horner of a peculiar nacreous substance possessing remark-
able optical properties, of which the author has already given an ac-
count*, furnished him with the means of instituting a more accurate
comparison between these two classes of phenomena. By a careful
and minute analysis of the reflected tints of its three first orders of
colours exhibited by a single film of the above mentioned substance,
they were found to consist of that part of the spectrum which gives
the predominating colour of the tint mixed with the rays on each
side of it. In analysing the transmitted beam, bands of the colours
complementary to the former are seen, with intervening dark bands ;
and when the analysis is made with a high magnifying power, the
spectrum is observed to be crossed throughout its whole extent with
alternate dark and coloured bands, increasing in number and dimi-
nishing in magnitude with the thickness of its plate. In the phseno-
* See Lond. and Edinb. Phil. Mag., vol. x. p. 201.

96 Royal Society.

mena of periodical colours there are three peculiarities demanding
notice ; first, that the dark lines change their places by varying the
inclination of the plate ; secondly, that two or more lines never co-
alesce into one ; and thirdly, that the colour of the luminous bands
in the complementary spectrum are the same as those of the original
spectrum when the thin plate is perfectly colourless. The author in-
stitutes a comparison of these phenomena with those of absorption
as exhibited by a solid, a fluid, and a gaseous body j employing as an
example of the first, smalt blue glass j of the second, the green sap
of vegetables ; and of the third, nitrous acid gas. No connecting
link between these phenomena appeared to exist, excepting that
both exhibited a divided or mutilated spectrum ; but even this com-
mon fact has not the same character in both. The nacreous substance
described by Mr. Horner, however, in some cases, when the plates
were small, was found to produce bands perfectly identical with those
of thin plates j while in other cases the bands were exactly similar to
those of coloured media. By employing the iridescent films of de-
composed glass, the author obtained combinations of films which gave,
by transmitted light, the most rich and splendid colours, surpassing
every thing he had previously seen among the colours either of na-
ture or of art. These facts have proved that the transmitted colours,
though wholly unlike those of thin plates, are yet produced by the
same causes, and are residuary, and generally complementary to the
sum of the reflected tints. Thus the author has succeeded in com-
pletely identifying in their primary features the two classes of facts;
the one resulting from absorption, the other from periodic action.
The minor points of difference, namely, the uniformity of the bands
and tints of absorbing media at all incidences, and the non-appear-
ance of the reflected tints in such media, are endeavoured to be ex-
plained by the introduction of several considerations, the complete
discussion of which the author reserves for the subject of a future
paper. From the phenomena of thin plates, of polarized tints,
and of absorption, the existence of a new property of light is deduced,
in virtue of which the reflecting force selects out of differently co-
loured rays of the same refrangibility rays of a particular colour, al-
lowing the others to pass into the transmitted ray ; a principle not
provided for in either of the theories of light to which the phenomena
of absorption are ultimately referable, and furnishing an explanation
of certain remarkable phsenomena of dichroism in doubly refracting
bodies, in which rays of the same refrangibility, but of different co-
lours, pass into the ordinary and extraordinary pencils.

A paper was read "On the hereditary instinctive propensities of
Animals." By Thomas Andrew Knight, Esq., F.R.S.

The author adduces, in support of the principle he had advanced
in his paper on the economy of bees *, namely, that instinctive pro-
pensities to the performance of certain actions are transmitted, inde-
pendently of education, from the parent to its offspring, several facts
which have fallen under his observation in the course of various ex-
periments commenced by him nearly sixty years ago and continued
* See Phil. Mag. and Annals, vol. iv. pp. 59, 60.

Royal Society. 07

to the present time. He relates that a young terrier, whose parents
had been trained to destroy pole-cats, and a young springing spaniel,
whose ancestors through many generations had been employed in
finding woodcocks, were reared together as companions j and that
each of them, immediately on seeing, and for the first time in its life,
the particular prey to which it was guided by hereditary instinct, pur-
sued it with intense eagerness, while it did not appear to notice that
which attracted its companion. In several instances he found that
young springing spaniels, wholly inexperienced, were very nearly as
expert in finding woodcocks as their well-trained parents. The habits
of the woodcock have in the course of the last sixty years undergone
considerable change, the fear of man having during that period become
much stronger by transmission through many successive generations.
The author believes that by continued education these hereditary pro-
pensities might be suppressed and others substituted : thus the habits
of the springing spaniel would never have been acquired, if shooting
on the wing had not been practised by man. A young dog, of
the variety usually called retrievers, on account of their being
trained to find and recover wounded game, performed this office,
although wholly untaught, quite as well as the best instructed dog.
The male and the female parents appear to possess similar powers of
transmitting to their offspring these hereditary feelings and propensi-
ties ; excepting in the case of hybrid progeny, in which the au-
thor thinks he has witnessed a decided prevalence of the character
of the male parent. With regard to dogs, the influence of one or
other of the parents, and sometimes of both, may occasionally be
traced, but without any constancy as to the particular predominance
of either sex.

A paper was read " On Meteorological deductions from Observa-
tions made at the Observatory at Port Louis in the Mauritius, during
the years 1833, 1834, and 1835." By John Augustus Lloyd, Esq.,
Surveyor-General of that Island, F.R.S. Communicated by Captain
Beaufort, R.N., Hydrographer to the Admiralty, F.R.S.

The observations, from which the results recorded in the present
paper were made, are nearly 50,000 in number, and were taken four
times each day, at the hours of 8 a.m. noon, 4 and 8 p.m. The de-
tails of the observations themselves are about to be forwarded to the
Royal Society; they relate to the states of the barometer, thermome-
ter, hygrometer, rain guage, and the appearance of the atmosphere
with regard to clearness or cloudiness.

June 1. — A paper was read, entitled, " On the development and
extinction of regular doubly refracting structures in the crystalline
lenses of animals after death." Bv Sir David Brewster, K.H., L.L.D.,
F.R.S.

Since the year 1816, when the author communicated to the Royal
Society an account of the doubly refracting structures which exist in
the crystalline lenses of fishes and other animals, he has examined a
great variety of recent lenses with the view of ascertaining the origin
of these structures, the order of their succession in different lenses>

Third Series. Vol. 1 1. No. 65. Supplement, July 1837. O

98 Geological Society.

and the purpose which they answer in the animal economy. He had
discovered in the lenses of many fishes the alternation of portions,
exerting:, the one a positive, and the other a negative refractive
action ; but in his subsequent investigations he met with the greatest
discrepancy as to the regularity of their arrangement. He found
that in quadrupeds the central structure is positive j while in fishes,
where there are three structures, it is always negative ; but their po-
sitive structure in the former case sometimes exists alone, with faint
traces of a negative structure, and sometimes it is followed by
another positive structure separated from the first by a black neutral
circle, in which the double refraction disappears ; at other times va-
rious other combinations of these structures are presented, Occa-
sionally, in the dark neutral line which separated two positive struc-
tures, he perceived a trace of an intervening structure, which seemed
to be either about to disappear or about to be developed. This con-
jecture was satisfactorily verified by a series of observations which he
made on the lenses of the sheep, the ox, and the horse, at different
ages, and also on the same lens, during the spontaneous changes
it undergoes when kept in distilled water. The negative structure
was in these experiments gradually developed at the space inter-
vening between the portions of the lens which had possessed the
positive structure ; and thus the same parts assumed in succession
doubly refractive actions of opposite kinds. The author intimates
his intention of pointing out, in a separate paper, the conclusions
deducible from these facts respecting the cause and cure of cataract.

GEOLOGICAL SOCIETY.

January4. — A paper entitled, " Some Observations on the Elevation
of the Strata on the Coast of Chili," by Alexander Caldcleugh, Esq.,
F.G.S., &c, was first read.

The author commences by stating, that previously to his return to
South America several circumstances induced him to suspend
his opinion as to the correctness of the details which had been
published of the effects of the earthquake of 1822. He thought that
the wreck in the Bay of Valparaiso, which had become accessible after
the earthquake, might have been thrown higher up by the heavy rollers,
and that rocks covered with testacea, which after the event were laid
dry, might likewise have been drifted. He also thought that the ac-
curacy of the observations might be doubted, because certain genera
of shells were stated to have been found adhering to the rocks in
Valparaiso Bay, which it was well known did not exist there ; and
because there was a vagueness in some of the statements, — as the
raising of the whole country from the foot of the Andes to far out at
sea. Since his return to South America, however, especially since
the earthquake of 1835, Mr. Caldcleugh has investigated the evi-
dences of change of level on the Chilian coast, and he states, in this
communication, his full conviction, that there have been many distinct
alterations in the relative level of land and sea.

Elevation of the Coast of Chili, 99

In detailing the results of his researches, he gives extracts from
all the historical and documentary evidence which he has been able
to consult, separating those proofs of accession of land which may be
ascribed to the deposition of sedimentary matter, from those which
demonstrate a vertical movement.

1. Accumulations of sedimentary matter. The Abate Molina states,
that the sea had long been gradually retiring, and even hazards the
observation, that in some places it had receded two, in others, espe-
cially near the mouth of rivers, six inches annually. Near the village
Talcahuano, Frezier says, that in 1712 the depth of water near the
shore was from five to six fathoms ; while Ulloa in 1744 gives five
fathoms, and Capt. Fitzroy has found the soundings near the same
spot to be only three and four fathoms. Frezier also states, that in
Valparaiso Bay vessels anchored close to the shore in eight or ten
fathoms ; and Ulloa, in fourteen fathoms at the distance of a cable
and a half; though at present the soundings at the same distance are
five to seven fathoms. In 1778, a Spanish seventy-four moored within
a cable's length of the arsenal in fifty fathoms water, where there are
now but six.

In the port of Coquimbo, according to Frezier, at half a cable's
length from the Tortoise Rock, the soundings were from six to ten
fathoms: they are now from three to four: it is also said that a whale
once passed between the rock and the main land. In the port of
Huasco, the same author gives the depth very near the shore to be
eighteen and twenty fathoms; but a vessel (the Byron) in 1831,
touched upon the ballast she had thrown out.

At Mr. Caldcleugh's first visit to Valparaiso in 1821, the town
consisted of one narrow causeway with houses on one side, and part
of the road which wound round an old fort, was washed by the sea at
every high tide. On a late visit to the port, he found that two lines
of houses had been built to seaward of the original street, and that
vessels of three or four hundred tons were obliged to anchor much
further out.

With respect to the dependence which ought to be placed on the
precedingobservations, he says, that the facilities for making them were
great, as vessels, to avoid the gusts from the gulleys, almost always
anchor on the same spot; and he remarks in explanation of this great
accumulation of detritus, that the rivers of Chili partake, with few
exceptions, of the nature of mountain torrents, swollen in winter by
the rains, and in summer by the melting of the snow in the great
Cordillera.

2. Evidences of vertical movements. — The author then proceeds to
point out the evidences of change between land and sea, which can-
not be accounted for by the accumulation of loose materials.

In Concepcion Bay there are two or three rocks which are not
noticed by Frezier or Ulloa, but of which seamen are now warned; and
the Belemrock has at present two fathoms upon it at low water, while
in the chart of Ulloa it is not laid down.

In the Bay of Valparaiso, outside of the inner point near the Que-

02

100 Geological Society.

brada de los Angeles, at a cable and a half or two cables from the
shore, is a rock which Ulloa directs to be looked out for with care
as it was not visible; at present it is not above 100 fathoms from
the shore ; and there is a ripple upon it at all times of the tide. Other
rocks near the Cruz de Reyes, which in 1821 were always covered
by the sea, are now four feet above the level of hi^h water mark.

In the port of Coquimbo are three rocks called the Pelicans, which
rise twelve feet above low tide; in 1710, according to Feuillee,
they were ajleur d'eau. Another rock, about twelve feet long, called
the Tortoise, in the time of Frezier and Feuillee, rose five or six feet
out of the water ; it is now nine feet above high water mark.

Mr. Caldcleugh then alludes to the beds of recent shells which
rest upon the edges of the sea cliffs from Concepcion to Copiapo,
and in consequence of their being found at levels varying from 14 to
300 feet, he conceives that the coast has been raised per gradus.

He next states, in addition to the evidences afforded by Mrs. Cal-
cot of the change of level produced by the earthquake of 1822, that
persons who escaped on board vessels, remarked that the sen-
tries before an old fort on the summit of the hill over the ruins of the
town, and previously visible from the feet upwards, had, subsequently
to the event, half the body concealed by the fore part of the cliffs*.
He also says that the street or causeway, which wound round an old
fort, and in 1821 was washed by the sea at every high tide, is now
seven feet above the wash of the sea at the high water line of ordi-
nary tides.

In conclusion, Mr. Caldcleugh gave an account of the effects pro-
duced by the earthquake of 1835, chiefly from the observations of
Capt. Fitzroy, full details of which have been published in the Trans-
actions of the Royal Society f and the Royal Geographical Society:}:.

The President then announced that he had received from the Fo-
reign Office the translation of an article published in the South Ame-
rican Journal, El Araucano, by Don Mariano Rivero ; but as none
except original communications were read before the Society, he
could only state that Don Mariano dissents entirely from the belief,
that earthquakes have produced vertical changes of level on the coast
of Chili.

This communication was accompanied by a letter from Col. Wal-
pole addressed to Lord Palmerston, an extract from which, read by
the Secretary, strongly supported Don Mariano Rivero's views.

A paper entitled "Observations of proofs of recent elevation on
the coast of Chili, made during the survey of His Majesty's ship

* In page 102 a part of the fort previously invisible is stated to have
become visible ; but this apparent discrepancy arises from the observations
alluded to by Mr. Caldcleugh having been made from the shipping, and
those by Mr. Darwin from a point on the land.

t Mr. Caldcleugh on the Great Earthquake in Chili, 1835. Phil. Trans.
1836, p. 21, noticed in Lond and Edinb. Phil. Mag., vol. viii. p. 148.

t Sketch of the surveying Voyage of His Majesty's Ship Beagle. Journal
of the Royal Geographical Society, vol. vi. p. 319.

Elevation of the Coast of Chili. 101

Beagle, commanded by Capt. Fitzroy, R.N.," by Charles Darwin,
Esq., F.G.S., was afterwards read.

The subject of recent elevations on the coast of Chili being, in the
opinion of many, still open to discussion, Mr. Darwin gives, in this
memoir, the results of his own observations. The portion of the coast,
more particularly examined by the author, extends from the river
Rapel, about sixty miles south of Valparaiso, to Conchali, about
eighty miles north of it.

Close to the mouth of the Rapel, dead barnacles occur adhering to
rocks three or four feet above the highest tidal level j and in the
neighbouring country recent marine shells are scattered abundantly
to the height of about 100 feet. Ten miles to the north, and at an
equal distance from the sea, is the village of Bucalemu, in the neigh-
bourhood of which are very extensive beds of recent shells. At the
bottom of the great valley of Maypo, and some miles from the coast,
marine shells of existing species are also numerous j and at St. An-
tonio, near the northern point of that river, are large quarries of
shells. Between this point and Valparaiso in the ravine Quebrada
Onda, the remains of a species of shell common on the coast, were
noticed by the author. Along the bold granitic coast south of the pro-
montory which forms the bay of Valparaiso, are numerous level and
horizontal beds of shells, constituting an almost continuous band,
elevated from 60 to 230 feet above the level of the sea. The shells
are brittle, but of various kinds, and are all similar and in similar pro-
portional numbers to those on the beach. They are mingled with
some earth, though packed closely together, and overlie a partially
consolidated breccia of granitic fragments which rests on the solid
rock. After a careful examination of these deposits, first by himself,
and afterwards with Mr. Alison, guarded by a recent inspection of
the heaps of shells accumulated by the natives in Tierra del Fuego,
Mr. Darwin was convinced that the shelly beds near Valparaiso were
formed when the sea occupied a different level. The following are
the principal circumstances which lead to this conviction. The great
number of the shells forming extensive horizontal beds, whereas the
heaps in Tierra del Fuego collected by the inhabitants, always retain a
conical figure: their position, at the extremities of headlands inac-
cessible from the sea, and unfit for strongholds, being without fresh
water: the large proportional number of extremely small shells : and
lastly, their brittle and decayed condition, the state of decomposition
having an evident relation to the comparative heights at which the
shells were lying. Comminuted shells were noticed by Mr. Darwin at
the heights of 560 and 1300 feet, but the evidence of^ their having
been part of a beach was not convincing.

At San Lorenzo in the bay of Callao, Mr. Darwin traced a similar
process of decay from perfect shells in the lowest beds to a mere
layer of calcareous powder in the highest. This phenomenon, he adds,
can be observed only in countries where rain never falls.

On the north side of the bay of Valparaiso, near the Vina del Mar,
is an abundance of elevated shells. Mr. Alison, by climbing a point

102 Geological Society,

of rock about fourteen feet above high water, and removing the dung
of sea fowls, discovered Balani adhering to the stone.

With respect to the historical evidence of the earthquake of 1822,
Mr. Darwin says that he met with no intelligent person who doubted
the rise of the land, or with any of the lower order who doubted that
the sea had fallen. He mentions also the altered position of the
wreck and of the rock in the bay ; and from a part of the fort being
in visible from a point ontheland before the earthquake,butvisibleafter-
wards, he infers that the movement of the land was unequal*. A
further proof of change, obtained for the author by Mr. Alison, is
shown by the remains of a sea-wall built in 1680, and over which,
up to 1817, the sea broke during the northerly gales. Mr. John
Martin, a ship carpenter of Valparaiso, remembers walking in 1819
on the beach at the foot of this wall, and he has been frequently
obliged to climb up to the street to avoid the sea. This wall is now
separated from the bay by two rows of houses, but a portion of what
appeared to be its base, carefully levelled by a resident engineer, was
found to be 11 feet 6 inches above high water mark. Mr. Darwin
does not ascribe the whole of this change to the earthquake of 1822,
and is of opinion that the alteration then produced was under three feet.
The church of San Augustin is believed to have been built in 1 634,
and the base of its walls is 19 feet 6 inches above high tide level ;
but there is a tradition that the sea formerly approached very close
to its foundations. Allowing, therefore, 4 feet 6 inches for its protec-
tion when built, the amount of change in 220 years is only 15 feet.
The granite recks which form the coast are also water-worn and hol-
lowed at about the same height, namely, 14 feet above the present
sea level. These data, Mr. Darwin is of opinion, prove, that though
the changes in 220 years have been small, yet that they were pre-
ceded by a period of comparative rest, during which there was time
for any former marks on the rocks to become obliterated.

The author then described the beds of recent shells between Con-
con and Quintero, about 100 feet above the sea level ; the deposits
near Plazilla and Catapilco ; and in the valley of Longotomo. On
the hills to the north of the latter, about 200 feet above the sea,
immense quantities of recent shells coat the surface or the sides of the
ravines ; and hence Mr. Darwin infers that the action of the sea de-
termined the minor inequalities of the land. Similar deposits, more
or less abounding in shells, were noticed by him near Guachen, and
in the valley of Quilimap. Close to Conchali, on the south side of
the bay, are two very distinct terrace-like plains, the lower being about
sixty feet high.

Mr. Darwin then gave a very brief notice respecting the marine
origin of the terraces at Coquimbo, described by Capt. Basil Hall
and discussed by Mr. Lyell. The proofs of the origin assigned to
them rest on the occurrence of recent shells in a friable calcareous
rock elevated 250 feet above the sea. This calcareous stratum passes
downwards into a shelly mass chiefly composed of fragments of Bala-
* See note * in page 100.

Geological Society. 103

nidse, and this again overlies a sandstone abounding with silicified
bones of gigantic sharks mingled with extinct species of oysters and
Pernse of a great size. The intermediate bed contains some shells in
common with the upper, in which all are recent, and with the lowest,
in which the greater number are extinct. The phenomena of the
parallel terraces and the elevated shells occur in a strongly marked
manner in the villages of Guasco and Copiapo, the latter being 350
miles to the north of Valparaiso: recent shells also occur at different
elevations at an equal distance to the south of it at Concepcion and
Imperial. Mr. Darwin believes that the land on the coast of Chili has
risen, though insensibly, since 1822. In the island of Chiloe he is fully
convinced, from oral testimony and the state of the coast, that a change
effected imperceptibly is now in progress. In support of this gradual
rise, independent of earthquakes, he states, that the eastern coast of
South America, bordering the Atlantic from the Rio Plata to the Strait
of Magellan, presents terraces containing recent shells ; yet in the pro-
vincesnearthe mouth of the Plata, earthquakes are never experienced j
anditisimpossibleto suppose that themost violentofthe Chilian earth-
quakes could produce these effects, as the shocks are scarcely trans-
mitted to the plains at the western foot of the Cordilleras. Hence, he
concludes that the earthquakes, volcanic eruptions, and sudden ele-
vations on the coast line of the Pacific, ought to be considered as ir-
regularities of action in some more widely extended phenomenon.

January 18.— A paper entitled, "An Account of a deposit con-
taining land shells at Gore Cliff, Isle of Wight," by J. S. Bowerbank,
Esq., F.G.S., was first read.

During a recent examination of the greersand of Gore Cliff, Mr.
Bowerbank discovered on the top of the cliffand overlying the chalk
marlbywhichitis capped, abedconsistingof detritus of chalk andchalk
marl, and inclosing, in every part examined by him, numerous spe-
cimens of existing species of land shells. The deposit extends from
nearlytheedgeoftheclifftothefootof St.Catherine'sDown, a distance
of about 660 yards. The range of the deposit he could not ascertain,
as at a short distance from the spot examined the cliff assumed
its usual perpendicular form ; but he is of opinion that it is consider-
able, or else that there are many such deposits, as he found fallen
masses of a similar bed near St. Lawrence and between Ventnor
and Bonchurch.

A letter addressed to Dr. Buckland by J. Wyatt, Esq., respecting
a trap dyke in the Penrhyn Slate Quarries near Bangor, Carmarthen-
shire, was then read.

These quarries were opened fifty years since, and the excavation is
now about 700 yards in length, 300 in breadth, and 90 below the
natural surface. In carrying on the highest opening of the quarry,
the men, a few months since, came suddenly in contact with a trap
dyke, which has since been cut through and proved to be 11 feet in
width. Its direction appears to be between W.N.W. and N.W., and
it intersects the bedding of the slate nearly at right angles. The dip
at present is almost 90°, the slight inclination being to the N.E. The
i( cheeks " of the dyke on the N.W. side, are broken conformably with

104 Geological Society.

the natural joints of the schist. The slate immediately in contuct with
the trap is, in some parts, quite flinty, having lost its fissile properties,
and the colour is changed from purple to black ; but at the distance
of two or three feet the slate recovers its natural colour and cleavage.

A notice of a successful attempt at boring for water at Mortlake in
Surrev, by William Richardson, Esq., F.G.S., was next read, an abs-
tract of which appears in No. 48 of the Society's Proceedings.

A paper " On the Strata usually termed Plastic Clay," by John
Morris, Esq., and communicated by the President, was then read.

The author commences by objecting to an arrangement of tertiary
formations in different countries according to the classification of the
Paris basin bv MM. Cuvier and Brongniart. He then refers to the
memoirs of Mr. Webster, Dr. Buckland, and Mr. Richardson, on the
strata immediately above the chalk in England, and proceeds to show
that they ought to be considered as belonging to the London clay.

For the sake of convenience in arranging their organic remains,
Mr. Morris makes three divisions of these beds : 1. those containing
the Reading oyster ; 2. the Woolwich and Upnor strata ; and 3. the
Bognor or lower arenaceous beds of the London clay.

The first division has been long well known in consequence of the
sections given by Mr. Webster* and Dr. Buckland f of the Catsgrove
pits near Reading; and has been subsequently described in a paper
by Mr. Rofe on the same district J. Mr. Morris gives the following
sections of this deposit at Northaw in Hertfordshire, and Headley in
Surrey.

Feet.

Northaw, Top, grey sand 20

green sand with oysters 1

grey sand 2

iron flint bed 8 inches.

chalk

Feet.

Headley, Top, red and green variegated marls 4

clay and sand 3

grey sand with oysters I

ash coloured sand

chalk

2. The Woolwich strata, also described by Mr. Webster § and Dr.
Buckland^]", extend along the south side of the Thames, and patches of
them are said to occur near Stifford** and Plaistow in Essex. They
are chiefly composed of sand, clay, pebbles, and calcareous rock, the
strata varying greatly in their thickness in different parts of even the
same pit ; and in their order of succession in different localities. At
Woolwich, Sundridge park, Upnor, and some other places, there is
also a marked distinction in the fossils of the upper beds from those
of the lower j the former being characterized by the prevalence of
freshwater or estuary shells of the genera Cyrena, Neritina, Melanopsis

• Geol. Trans., First Series, vol. ii. p. 198. f Ibid. vol. iv. p. 278.

\ Geol. Proceedings, vol. ii. p. 72, or Lond. and Edinb. Phil. Mag. vol. v.
p. 212. § Geol. Trans., First Series, vol. ii. pp. 196—221.

f Ibid. vol. iv. p.284. ** Ibid. vol. ii. p. 196.

( j eological Society, 105

and Planorbis, associated with marine shells. How far this distinction
may be owing to the action of a river, Mr. Morris says it may be difficult
to determine, as the recent species of the above genera have variable
habits. The principal localities at which the Woolwich beds have
been noticed are, Sundridge park near Bromley, Chiselhurst, Orping-
ton, Beckenham, Sydenham, Counter Hill, Loam-pit hill near Lewis-
ham, the Thames Tunnel, Vauxhall, the road leading from Oldfield to
Plumstead; the ninth milestone beyond Shooter's Hill, Erith ballast-
pit, Bexley Heath, Swanscombe Wood, Green Street near Stoke, and
Upnor near Rochester. ,

The following sections presented at the last locality, illustrate the
variations in different parts of the same pit.

Feot.
South End, Top, brown clay with fragments of chalk and

chalk flints 10

fine calcareous clay 3

sand with bluish flint pebbles, and numerous re-
mains of Cyrena, Cerithium, Planorbis, Cy-

therea, Pectunculus Cardium,and Natica. . I

white sand, with occasionally layers of shells. ... 4
blue and brown clay with compressed Cyrena,

Cerithium and Ostrea 4

lignite in gray sand 1

white sand, lower part containing pebbles 20

North End, Top, brown clay, &c 14

sand with pebbles and shells 1$

sand chiefly white, in the upper part thin seams

of shells 15

brown and blue clay, with compressed shells

intermingled with sand 6

uirplish sandy clay with ochreous concretions . . 2

lignite in sulphur-coloured clay and sand.. ..... . 8 inches.

white sand

With respect to the geological position of the Woolwich beds,
Mr. Morris is of opinion that they ought to be assigned to the lower
part of the London clay, as they occupy the same position, with re-
ference to the chalk, as the Bognor strata.

3. The Bognor or lower arenaceous beds of the London clay are
then described, and the following list given of the localities at which
they have been noticed : Pegwell Bay (Isle of Thanet): Heme Bay*,
Faversham, Hampstead well f, Watford, Egham, Bray, BinfieldJ,
Catsgrove quarry near Reading§, Alum Bay, Bognor^f and Stubbing-
ton. At all these localities the strata are considered by Mr. Morris
to be contemporaneous and to belong to the lower part of the London

* See Abstract of Mr. Richardson's Memoir, Geol. Proceedings, vol. ii.
p. 78. or L. and E. Phil. Mag. vol. v. p. 21 9.

f Abstract of Mr. Wetherell's Memoir, Geol. Proceedings, vol. ii. p. 93,
or L. and E. Phil. Mag. vol. v. p. 295.

X Mr. Warburton's Memoir, Geol. Trans., Second Series, vol. i. p. 52.

* Abstract of Mr. Rofe's paper, Geol. Proceedings, vol. ii. p. 72, or L.
and E. Phil. Mag. vol. v. p. 212.

H Mr. Webster's paper, Geol. Trans., First Series, vol. ii. p. 190.
Third Series. Vol. 1 1. No. 65. Supplement, July 1837. P

in

I 06 Geological Society.

clay, reposing in some instances immediately on the chalk. Their mine-
ral character is remarkably persistent, consisting of grayish green sands
with layers of pebbles, but sometimes passing into sandstone and
limestone. The fossils, which in some localities are numerous, agree
specifically with the well-known Bognor shells; those imbedded in the
sands being in good preservation but those in the rock chalky and
friable. From the position occupied by these beds Mr. Morris is in-
duced to consider them as the equivalents of the lower beds of Wool-
wich, Upnor, &c, and in support of this opinion alludes to the strata
of calcaire grossier which rest immediately upon chalk at Meudon.

A Memoir on the Geology of Suffolk, by the Rev. W. B. Clarke,
F.G.S., was then commenced.

Feb. 1. — A paper, " On the occurrence of Keuper-Sandstone in
the upper region of the New Red Sandstone formation or Poikilitic
system in England and Wales/' by Professor Buckland, D.D., V.P.G.S.,
was first read.

The term Keuper is applied in Germany to the entire series of red
and variegated marls and sandstones, which lie between the lias and
muschel-kalk. Several of these sandstone beds afford a valuable
building stone, specimens of which from the quarries of Stuttgard
and of Sinzheim, near Heidelberg, were presented by the author to
the Society. Dr. Buckland has identified several varieties of this
German Keuper-sandstone with sandstones which occupy an analo-
gous position in England in the lower region of the red rock marl.

The total absence of the Muschel-kalk in this country, has left us
without that obvious division which it affords in Germany, between
sandstones of the era of the red marl or Keuper, and those more ancient
new red sandstones which are distinguished on the Continent by the
name of Gres bigarre, or Gres de Vosges, and which in England, oc-
cupy a large space between the red rock marl and magnesian lime-
stone.

In the vicinity of Warwick, which forms the principal example
cited in the present memoir, an excellent section is seen in Guy's
Cliff, and a considerable extent of surface is occupied by Keuper-
sandstone, which emerges from beneath the red rock marl, near that
town and Leamington, and occupies a breadth of three or four miles be-
tween Warwick and Kenilworth; at the latter place the Vosges sand-
stone rises from beneath it, affording the materials for the construc-
tion of the castle of Kenilworth, as the Keuper-sandstone has afforded
those of the castle and other ancient buildings at Warwick.

In the absence of the Muschel-kalk, there is here no obvious proof
of any interval between the deposition of the new red sandstone of
Kenilworth, and of the olive-coloured Keuper-sandstone which rests
immediately upon it, and although the mineral condition of this latter
sandstone agrees with that of the Keuper-sandstone of Germany,
some doubt might have remained as to the identity of strata so distant
from each other, without the aid afforded by organic remains. In
1823, part of the jaw and other bones of a Saurian, found in the
sandstone of Guy's Cliff* near Warwick, were presented to the Ox-
ford Museum, by the late Butic Greathead, Esq. ; Dr. Buckland has

Discovery qftheKeuper in England and Wales. 107

identified these with the remains of the Phytosaurus, which in 1835
he saw in the Museum at Wirtemberg; and, as this genus has hitherto
been found in no other formation than the Keuper, it leaves little
doubt as to the identity of the Warwick sandstone with the Keuper-
sandstone of Germany. Fragments of vegetables also are dispersed
through the Warwick sandstone, in the same state of imperfect pre-
servation as the greater part of those in the Keuper of Stuttgard.

In October 1836, further remains, apparently of Phytosaurus, were
found at Warwick by Dr. Lloyd of Leamington, who is engaged in
tracing the extent of the Keuper throughout this district.

Dr. Buckiand has also recognised the Keuper-sandstone in the
quarries of Sutton Mallet near Bridgewater j and of Rumwell Heale
and Oake near Taunton ; the latter have supplied the freestone used
in the towers and bridges at the town of Taunton.

In the cliffs at Oreham, two miles E. of Exmouth, there are beds
of sandstone, probably referrible to the Keuper formation, which have
supplied the olive-coloured sandstone of which the cathedral of Exeter
is built ; and at Pyle, in Glamorganshire, a few miles E. of Neath, a
valuable building-stone lately employed in constructing the castle of
Margum, is obtained from strata, which the author also refers to the
Keuper-sandstone of Germany.

Mr. Murchison has noticed Keuper-sandstone in several localities
in Gloucestershire and Worcestershire, near Tewkesbury and Ne-
went.

A paper "On the Geological Structure and Phenomena of the north-
ern part of the Cotentin, and particularly of the immediate vicinity
of Cherbourg," by the Rev. W. B. Clarke, F.G.S., was then read.

In an account of the Cotentin published in the 35th volume of
the Journal des Mines, M. Alexander Brongniart gives a full account
of the limestone, slates, quartz rock and syenite or granite com-
posing the country; but the chief object of that memoir is to prove
the comparatively recent origin of the granitic rocks.

Mr. Clarke, in detailing the characters of the formations follows
closely the account of M. Brongniart, and adopts fully the views of
that geologist respecting the age of the granite. He also quotes
Prof. Sedgwick's observations on the comparatively recent origin of the
granite of Cornwall, and the adjacent portion of Devonshire; and
points out the general agreement in structure of that district with
the Cotentin. The characters of the formations are further noticed
in the abstract of the paper given in No. 48 of the Proceedings.

Feb. 22 — A paper on the Geology of Cutch, by Captain Grant, of
the Bombay Engineers, and communicated by Charles Lyell, Esq.,
F.G.S., was read.

This district, so highly interesting on account of the phenomena
which accompanied the earthquake that devastated it in 18 If)*, is
situated near the eastern branch of the Indus, between 22 and 24
degrees of north latitude, and 68 and 72 degrees of east longitude.
On the north, it is bounded by the Grand Runn, and the Thur or

* A collection of papers relative to this earthquake appeared in Phil.
Mag. First Series, vol. Ixiii. p. I05etseq.

P2

108 Geological Society.

Little Desert, on the south by the Gulf of Cutch and the Indian Ocean,
on the east by the province of Guzerat, and on the west by the eastern
branch of the Indus and the territory of Sinde. Its superficial con-
tents are about 6500 square miles. The surface is traversed by three
ranges of hills, having in general un east and west direction. The
hills constituting the northern chain, which borders the Runn, present
a perpendicular capping of sandstone, surmounting towards the north
a sloping talus, and towards the south an inclined plane, both com-
posed of laminated clay and slaty limestone, with occasionally layers
of sandstone. The second or central range, is constituted partly of
the formation last mentioned , and partly of another consisting of sand-
stone and shale. The third or southern, is formed wholly of volcanic
rocks, but has nearly the same linear direction as the others.

To the south of the last range is an extensive flat, composed of a
deposit, considered by Capt. Grant to be tertiary, and of an alluvial
band, bordering the sea coast.

The first of these formations, which constitutes the northern range
of .hills, abounds with Ammonites, Nautili, Belemnites, Trigoniae, and
other fossils characteristic of the oolitic system of England. The for-
mation of sandstone and shale, which occupies a much greater surface,
contains, in various localities, thin beds of coal, sometimes very im-
pure, but at others tolerably good j also layers of iron ore ; and in
the shale as well as in the sandstone, casts of reeds and impressions of
ferns are stated to occur. With respect to the relative age of these
two formations, Capt. Grant was unable to procure any decisive
information; but he thinks that the sandstone and shale system
passes beneath that of laminated clay and limestone.

The iron ore is smelted by the natives to some extent, particularly
near the town ofDoodye. The variety generally selected, on account
of the imperfect apparatus employed, has a spongiform texture, small
upecific gravity, and is easily frangible. The ore is broken into small
pieces and disposed in layers, alternately with others of charcoal, in a
rude open furnace, acted upon by two small bellows made of sheep
skin. The metal on being fused, falls into a small hole at the bottom
of the furnace, whence it is removed into an inclosed furnace, and
subjected to the same blasts until it acquires a white heat, when it is
taken out and beaten into a bar. A considerable quantity of iron was
formerly made from another variety of ore, found in the superficial
soil at the north-western extremity of Cutch.

In one part of the province, the author noticed a deposit of variegated
sandstone and marl, but was unable to determine its position with
respect to the other formations. It is covered, in part, by an aluminous
earth, on which rests a bed of red clay. The former, when visited by
Capt. Grant, had been burning spontaneously for a long time, sending
forth a suffocating sulphureous smoke. Considerable quantities of
alum are made from the earth and exported to Bombay.

Another formation, described by the author, occurs south of Luck-
put, near the eastern branch of the Indus. It consists of soft and
hard, whitish limestone, containing innumerable Nummulites and
Fascioliles, also Echini, Spatangi, Ostrea and Corals.

Geological Society. 1 09

The tertiary deposit consists of a hard, argillaceous grit Covered b y
a conglomerate. The organic remains, which are very numerous, are
often disposed in beds confined to one species ; the prevaling gen era
being Area, Pecten, Ostrea, Cardium, Conus, Cypraea, Ovula, Fus us,
Trochus, Solarium, Strombus, and Cassis. Patches of Corals, two or
three acres in extent, sometimes also occur.

Under the head of alluvial tracts, Capt. Grant gave an account
of changes, produced along the southern coast by the deposition of
sediment. At Mandavee is a ruin, at a spot called the old Bun-
der or quay, now about three miles inland j and in the centre of
the town is a small temple, built upon a rocky foundation, but said to
have stood in the sea when the old Bunder was the landing place.
At other localities in the Gulf of Cutch, similar processes are going
on, rendering it necessary to remove the landing-places frequently
further seaward. The rapid progress of these accumulations is
ascribed to the sea, during nine months washing back the sandy
detritus, brought down by the periodical floods. The same ope-
ration is also in progress at places separated from the main waters
of the gulf by small creeks or inlets, some of which penetrate six
or seven miles from the coast, through a tract covered with shrubs.
At low-water the whole of these plants are exposed down to their
roots, but at high tide merely their tops are visible, so that boats
sail through a completely marine forest. The growth of these shrubs
is rapid, and the sailors have, constantly to force the boats through
the upper branches, particularly at the angles of the creeks, when
they wish to save a tack. The stems and lower branches are
covered with testacea, whilst the upper are occupied by numerous
water-fowl. The land gains in this dictrict, by the deposition of
the muddy contents of the small streams during the monsoon, when
the water passing very slowly between the stems of the shrubs, a great
portion of the matter held in suspension, is precipitated. This alluvial
district occurs only on the southern coast of the Province. In August,
1834, the rains were very violent and continuous, and the river which
flows past Nurra, on the borders of the Grand Runn, covered with a
fine soil a surface of nearly 1000 acres. On the opposite or southern
side of Cutch, not far from Mandavee, 300 acres were washed away ;
and not far from the same spot, half a small village was removed bodily
into the sea.

Volcanic Rocks. — Besides the southern range of hills already stated
to be entirely composed of trap or volcanic rocks, other extensive di-
stricts of the same nature occur between the northern and central
ranges, and to the south of Luckput ; besides innumerable minor
outbursts, some of which forming small conical hills, are arranged
around a central area. The author noticed no recent crater, unless
the hill, called Denudar, be considered as such, and down the flanks
of which he traced a lava stream. The volcanic rocks consist of
several varieties of basalt, often columnar, amygdaloid, green-
stone, and trachyte. Capt. Grant described these rocks in great
detail, as well as the effects evidently produced by them, enumerating
a great variety of instances, in which the disturbance of the strata can

110 Geological Society.

be traced, in the clearest manner, to the protrusion of trap. In some
cases the volcanic mounds are themselves cracked or fissured from top
to bottom.

That the igneous eruptions occurred at many distinct periods,
Capt. Grant showed by sections, in which beds of trap alternate with
others of crystalline limestone, calcareous tuff, and a calcareous grit,
which sometimes contains angular fragments of basalt ; and by beds of
very different characters reposing on each other.

Among the phenomena connected apparently with volcanic action,
the author described a number of mounds, varying in diameter from
3 to 20 yards, and covered with small tabular plates of sandstone, the
lines of fracture radiating, though irregularly, from a centre. In some
instances the summits of these little mounds having been removed,
a regular circle of stones appeared, inclosing an area of sandstone,
the fracture of the stones decidedly radiating as the stones of an arch.
In other instances they resembled small hillocks, from the upper part
of which the outer coating or tabular plates had generally fallen away,
and the whole consisted of a heap of broken masses of rock.

The author then described what he considers to be a very recent
volcanic outburst. It is situated in the nummulitic limestone, near
the village of Wag£-ke-pudda, and forms a rather high flat basin,
or table land of about two square miles, composed of calcareous marl,
and flanked by low irregular hills of ironstone and gravel. The
sides are broken by fissures, ravines, and hollows, and the bed of
the basin is covered with hillocks of loose volcanic scoriae of various
colours. Within the basin are also several small craters or circular
spaces, surrounded imperfectly by walls of columnar, globular, or
friable basalt. These basaltic walls, however, he conceives, are of an-
terior date to the mounds of scoriae, which he is of opinion cannot be
of great antiquity, on account of the facility with which their loose mate-
rials are removedby atmospheric agents. Other similar outbursts were
also described.

The paper concluded with an account of the Great Runn, a district
(exclusive of the elevated tracts called " the Bunnee and Islands")
of 7000 square miles. This singular region, as already described by
Capt. Burns, consists of a sandy flat, dry for the greater part of the
year, but during the prevalence of the south-west winds, con-
verted into an inland sea, passable however on camels. Capt.
Grant believes that its present oscillating position between land and
water, is due to an elevation of the Runn, and not to a change in the
level of the seaj and in support of his opinion adduced the alterations
both of elevation and depression of land, by the earthquake of 1819.
He described also several extraordinary walls of rock, thrown up ap-
parently by volcanic action, sometimes assuming a dome shape, at
others segments of circles or straight lines.

March 8. — The reading of a paper M On the Geological structure and
phaenomena of Suffolk, and its physical relations with Norfolk and Es-
sex y by the Rev. W. B. Clarke, F.G.S., began on the 18th of
January, was concluded.

The observations detailed in this memoir were made during 1827,

Geological Society. Ill

1828, and 1829, and are arranged under the beads of the physical
features of the county, the geological structure, and the effects
produced by causes now in action.

Physical Features. — The general form of Suffolk is an oblong of
about 47 miles by 27, bounded on the east by the German Ocean, the
south by the river Stour, the west by the Ouse and Lark, and the north
by the Little Ouse and Waveney. It is impossible, says Mr. Clarke, not
to be struck with the fact, that whilst some of these river-courses have
an east and west direction, others flow from N.N. W. to S.S. E., and that
the coast section from Harwich to Orford is nearly parallel with the
latter j and he adds, if these observations be extended to Norfolk and
Essex, counties similar in geological structure, an accordance will be
found in the direction of their rivers and estuaries.

How far these river channels may be due to dynamical action,
operating from below, the author thinks it is difficult to determine ; but
he is of opinion that when they are studied with reference to the proofs
of violent derangement in the north, east, and west corners of Nor-
folk, and the almost unequivocal evidence of disturbance on the
coast of Suffolk, there is sufficient reason for assuming, that the
drainage of Norfolk, Suffolk, and Essex has been induced by a violent
strain acting from below, and throwing the whole mass of the country
into a position, by which 1200 square miles of Norfolk and 220 of Suf-
folk are drained by the Yare, and about 2000 of the latter county at its
south-east corner.

In addition to these facts, Mr. Clarke says, that the estuaries of the
Aide, the Deben, the Orwell, and the Stour, having an average length
of 1 1 or 12 miles, meet the fresh water at nearly the same distance
from the sea, and at the boundary line of the great continuous bed of
diluvium, which covers so extensive an area in that part of England ;
only detached patches of greater or less extent being found to the east
of the line.

The Geological Structure. — The formations of which Suffolk
consists, are chalk, the plastic and London clays, crag, diluvium or an-
cient superficial detritus, and recent lacustrine deposits ; the first occu-
pying the N.W. portion of the county, the second, third, and fourth the
south-eastern, and the fifth or diluvium, the intermediate part, restingon
all the preceding deposits ; while the sixth or lacustrine accumulations
are of very local occurrence.

Chalk. — This formation in the S.E. of Suffolk, is principallyexposed
in the banks of the estuaries and rivers, and contains the usual plates
and nodules of flints, as well as the fossils characteristic of the upper
chalk. In making a well at Harwich, at the depth of 93 feet, and
between the white and gray chalk, a stratum 10 feet thick of sandy,
gritty chalk was penetrated. The beds are in general nearly horizon-
tal, declining gently to the south-east, but they sometimes dip at
considerable angles, and the surface appears to have been violently
dislocated and worn into deep gulleys, locally called sand-galls. At
Harwich in making two wells only 70 yards apart, the chalk was
reached in the northern at the depth of 88 feet, but in the southern at
64 feet. Where the formation has been denuded by the rivers, the

1 1 2 Geological Society.

tertiary beds frequently rest upon it; but where it rises into an eleva-
tion above the river levels, it is covered altogether by diluvium.

Plastic clay. — There is some difficulty in separating this deposit
from the diluvium of Suffolk. At certain points, however, it displays
the samebeds of mottled clay and sands with pebbles, which characterize
it in other parts of the kingdom ; and it is occasionally exposed be-
tween the London clay and chalk. From its local occurrence Mr.
Clarke is of opinion, that it has been subjected to denudating agents,
ajid that it has partaken, in part at least, of the dislocations which have
affected the chalk.

London clay. — This formation presents, in Suffolk, the usual cha-
racters. At Walton on the Naze and Bawdsey, considerable quanti-
ties of pyritous vegetable remains are washed up from a bed below th^
level of the sea; and are said to rival in variety and abundance the
Sheppy fossils. The furthest western point at which the formation is
visible, is Layham near Hadleigh, the country beyond being covered
by diluvial clay. It constitutes, however, the substratum of all the
estuaries which intersect the S.E. of Suffolk, and the coast section
from Orford Ness to Walton Naze, being everywhere capped by crag.
This section is constantly varying in its features, but presented when
theauthor examined it, in 1827, the appearance of beds once horizontal,
having been upheaved in some places and depressed in others ; but
to what extent these disturbances may have been produced by elevatory
movements, the action of the sea, or the undermining of land springs,
he could not satisfactorily determine. The supply of water obtained
from the formation appears to be governed by local phaenomena. At
Kast Bergholt, a well was dug to the depth of 40 feet in London clay,
without success ; but in excavating a cellar a few feet from the well, a
copious spring was tapped, and conveyed into it by a channel. In the
river Ore is an island of London clay, in which two wells were sunk
through 80 feet of clay, 3 inches of rock and 20 feet of sand. The
water rose to the surface, had a strong smell of sulphur, but no saline
taste, though it overflowed only during high tide in the river. The
fossils mentioned by the author, are confined to fishes' teeth, and the
occasional occurrence of shells. He mentions that land animals have
undoubtedly been found in the London clay, as the tusk of an elephant
at Harwich, but he is of opinion that the greater part of such remains,
said to have been obtained from the formation, have been washed out
either of the crag or the diluvium.

Crag. — Mr. Clarke says the terra crag is applied in Suffolk only
to the shelly beds, and the word gravel to the associated beds of peb-
bles, as well as to the accumulation of superficial pebbles. The por-
tion of the county occupied by the deposit, is bounded on the west by
a line connecting the water-head of the estuaries ; and the most
southern point at which it is now visible is Blackbrooke Hill, near Ded-
ham, the patch at Walton Naze having been entirely removed by the
partial destruction of the cliffs. Sand, however, containing shells occurs
at Ardleigh Wood near Colchester, and it has been said that Danberry
Hill, near Chelmsford, is capped by crag; but Mr. Clarke doubts the
.accuracy of this observation. The general surface of the area assigned

Geological Society. 1 1 3

to the deposit in Suffolk, is a platform of nearly regular elevation, which
appears to have been worn into ridges and valleys by currents acting
in parallel lines from N.E.toS.W., and the cliffs both in the interior
and on the coast, are sections of these ridges. The dip of the London
clay corresponds with that of the crag, and therefore Mr. Clarke in-
fers, that both were acted upon by the same agents, and while they
were beneath the level of the sea.

According to the author's observation, the deposit nowhere extends
more than twelve or thirteen miles from the coast, and at Pakefield,
where the diluvial clay comes to the very edge of the sea, it disappears
as a surface deposit, but is visible at intervals further north, between
that point and Cromer. Mr. Clarke also states, that though undoubt-
edly crag is discernible here and there, in situ, as a regular formation
north of the Waveny, yet he by no means allows that it is regularly
stratified, as an undisturbed deposit, between Leiston and Pakefield.
He is fully convinced from observation, that the diluvial clay and crag
are distinct deposits ; and he is almost equally convinced, that if the
crag has any share in the formation of the cliffs between the Blithe
and Lake Lothing,ithas been introduced by disturbances of a simi-
lar nature to those which are presented in the cliffs of East Norfolk.
That the localities in dispute may have been once occupied by crag,
there is no reason todeny, but they now present no traces of an undis-
turbed deposit.

To previous descriptions of the structure of the crag, the author
states that he has nothing to add, except that where the shells are
not visible, the sands contain a slight mixture of calcareous
matter.

He objects to the separation of the beds with shells from those
without, and shows that the shifting of a sand -bank, would correctly
account for the occasional occurrence of beds of sand 30 feet thick,
resting upon strata inclosing testacea.

Believing that the true rationale of the crag is to be found in the
hypothesis of sandbanks, inhabited by testacea, and situated in a
tidal way exposed to violent fluctuations of the sea, as well as subject
to drifts of extraneous matter from land waters, the author sees nothing
extraordinary in the idea that accumulations of sand and shingle may
have formed a part of that deposit in which the crag is regularly
stratified j but he cannot consent to such accumulations, though con-
temporaneous with the crag, being classed under that name, much less
can he consent to diluvial clay being also included in it.

If then, says Mr. Clarke, we assume that in this tertiary sea, sand-
banks were formed, around the shelves and under the lea of which
testacea collected, lived and died, as at present, many of the phse-
nomena of the crag may be readily solved, and we shall not need to
wonder why the bivalve shells are found lying with the flat sides to
the strata of sand ; why the young are congregated in one group, and
the old in another j why pebbles are found covered with balani ; or why
the remains of terrestrial mammalia are associated with those of whale*
and fishes.

Third Series. Vol. 11. No. 65. Supplement, July 1837. Q

114 Geological Society,

With respect to Mr. Charlesworth's* subdivision of the crag into
two ages, the author fully agrees with a qualification of the word
age. If that gentleman had said different periods of the same age,
Mr. Clarke would find no difficulty in admitting the justness of the
classification j as not only species but genera of shells are differ-
ently grouped according to localities. The Norwich crag, he also
admits, differs from the Suffolk, and on the authority of Mr. Wood-
ward alludes to bouldered Suffolk shells occurring at Thorpe, in
Norfolk.

The corals of the lower bed of the Suffolk crag, the author is of
opinion, betoken a warmer climate, and he says, if during the crag era
the earth gradually cooled, the change from a coralline deposit to one
more nearly related to the inhabitants of the present era, would be
the natural and inevitable result.

Mr. Clarke fully assents to the observation brought forward by
Mr. Charlesworth in a paper, read before the British Association at
Bristolt}on the mixed nature of the deposits now forming on the coasts
of England, in which the remains of the adjacent cliffs are intermingled
with the shells of existing species ; and adduces examples with which
he was acquainted, long before the reading of that paper.

The author then offers some further remarks on the necessity of
separating the diluvium from the crag. He is of opinion that the gravel
found in the latter, if carefully observed, will be acknowledged to dif-
fer from regular diluvial gravel, and that its occurrence only betokens a
diluvial action during the period of the crag. That such actions have
been often repeated, he says there can be no doubt, for the beds of
superficial gravel of Suffolk and Dorsetshire, are evidently not of the
same period; and no one who has studied gravel deposits accurately,
can refuse to admit, that there have been more than one diluvial
action, since the deposition of the tertiary formations. In Norfolk,
he adds, it is true, the crag is involved in the clay, but if this clay
which in that county is 400 feet and in Suffolk 300 feet thick, be one
with the crag, it is most curious that a line of demarcation should
actually exist, between the districts in Suffolk occupied by these de-
posits ; and that the clay is never found below or intermixed with the
crag. Moreover this diluvial clay has been traced not only into Nor-
folk but into Cambridgeshire and Essex, close up to the metropolis.
In Suffolk the same line which bounds the London clay bounds the
diluvial. By an extension of Mr. Lyeli's argument all diluvial depo-
sits, the author observes, might be included in the crag, and all other
formations considered as diluvial. The only rational conclusion in
Mr. Clarke's opinion, is, that during the crag era an extraordinary
convulsion took place which shook the whole country. He gives also
one or two instances in which diluvial clay and gravel have been in-
troduced into cavities in the crag from overlying beds of superficial
detritus.

* Mr. Charlesworth's paper in which this division is established will be
found in Lond. and Edinb. Phil. Mag. vol. vii. p. 81 See also p. 464 of
the same volume, vol. viii. p. 529, and the paper referred to in the next note.

t This paper appeared in L. and E. Phil. Mag. vol. x. p. 1.

Geological Society. 1 ] 5

On the conchological history of the crag, Mr. Clarke offers no re-
marks, partly because it did not fall within his object in writing the
paper, and partly because the data which he formerly collected have
been lost.

Diluvium. — The diluvium of Suffolk may be divided into three
classes : 1 , clay ; 2, gravel j and 3, erratic blocks.

1. Clay. — This division covers a considerable portion of the
county, and extends into Norfolk, Cambridgeshire, and Essex, rising
to a considerable elevation in High Suffolk, and attaining near Cromer,
a thickness of 400 feet. A considerable portion of the clay is of a
yellowish hue, but the greater part is blue j and both varieties contain
chalk pebbles, sometimes disposed in layers but more commonly di-
spersed, a character by which the diluvial may be distinguished from
the London or plastic clay. It is difficult to determine the origin of
this argillaceous deposit ; but the author is inclined to think, that the
yellowish portion may have been derived from the plastic clays, and
the blue from the clays below the chalk. Fragments of coal have
been found in the diluvium at Lavenham, also fragments of mica slate
containing garnets and tourmaline. Specimens of a similar rock were
obtained by Mr. R. C. Taylor, at Cromer, with masses of granite, por-
phyry, trap, oolites, &c* At Baliingdon Hill near Sudbury, Mr. Brown
has procured thirty varieties of primary, secondary, and tertiary rocks.
Comparatively few flints occur in the clay. At Ickworth a beautiful
specimen of the Dudley trilobite was obtained in making a drain :
and at various other localities, numerous species of tertiary and
secondary fossils abound.

It is inferred that the clay contains cavities, as streams of noxious
air occasionally issue from fissures.

2. Gravel. — The gravel is less generally diffused than the clay, and
is considered by Mr. Clarke to have been partly deposited at a distinct
period. In some cases, it consists merely of unrolled flints, left in
situ by the dissolution of the chalk ; in others, large masses of flint
slightly mixed with chalk pebbles are imbedded in sand ; and occa-
sionally flints are intermingled with boulders of various dimensions,
and sometimes unknown origin. Many of these extraneous fragments,
he thinks, may have been washed out of the clay j and he shows that
the river valleys have been excavated through both the clay and the
gravel. With respect to the relative proportional quantity of each
ingredient, chalk flints are said to be the most numerous, primary and
transition rocks the next in abundance, and secondary and tertiary
the fewest in number; the absence of the two latter being explained
by their inferior hardness.

3. Erratic blocks. — These occur in great abundance, and occasion-
ally of vast size. They are sometimes found in the river valleys, and
sometimes on the level platforms and hills. They agree in lithological
characters with the smaller fragments of the gravel, and are con-
sidered to be of the same diluvial origin ; but are so conspicuous as
to deserve a distinct notice.

Lacustrine deposits. — Under this head the author alludes to the bed
containing freshwater shells, discovered by Mr. Charlesworth and Mr.
• See Phil. Mag. and Annals, N.S. vol. i. p. 346.
Q 2

1 1 6 Geological Society.

Wood on the banks of the Stour at Sutton ; and that described by
Mr. Brown at Copford near Colchester, which contains similar shells,
also bones of the ox and deer. Accumulations containing the same
testacea, occur at Grays near Purfleet, and at Southend in Essex, but
associated with remains of the elephant, rhinoceros, deer, ox, bear,
&c. In the bed at Grays rounded pebbles of chalk occur, agreeing
with those found in the diluvium, and from which they were probably
derived.

Causes in Action. — In this division of the memoir are described,
1st, the alluvial accumulations ; 2ndly, the changes in the river
courses ; and 3rdly, the action of the sea on the coast. In illustration
of the two first, Mr. Clarke enters into a discussion on the supposed
position of the Roman station, Ad Ansam, and the alterations which
must have taken place, if the site assigned to it be correct. He then
proceeds to the action of the tides on the cliffs.

His first acquaintance with the coast about Bawdsey was in 1814,
and between that period and 1829, a battery which once stood 100
yards beyond the present low-watermark, has been dismantled ; and
the life-boat house has been three times removed, to a distance at least
a quarter of a mile in rear of its original position.

The destruction between the Aide and Bawdsey cliff during the last
20 years, is calculated to have been upwards of 100 acres ; and the
coast between that cliff and Bawdsey Haven, is stated to have dimi-
nished about two yards annually. Similar remarks apply to the cliff
between the Deben and Harwich harbour, batteries and martello
towers having been successively undermined.

In 941 the church at Walton Naze was at a considerable distance
inland ; about 50 years since the church and burial-ground remained,
but not a vestige of either is left. In 885 a sea fight took place be-
tween Alfred and the Danes at the mouth of the Stour, where the
shingle bank now is. Harwich is also stated to have arisen in con-
sequence of the destruction of Orwell, which stood on the spot
called the West Rocks, and was overwhelmed by an inroad of the sea,
since the Conquest. During the period, however, that these destructive
changes have been proceeding on one side of Harwich harbour,
sandbanks have accumulated at another, and compelled the Stour
and the Orwell to open a new line of communication with the sea.

The author then gives the following conclusions as deducible from
the statements in the body of the memoir.

1. The substratum of the whole of Suffolk, Norfolk, and Essex is
chalk, which appears to have been dislocated and worn into deep hol-
lows by the action of water, previously to the commencement of the
tertiary era.

2. On this abraded surface the plastic clays and sands were
formed, but not over the whole area.

3. Partly on these beds and partly on the chalk, the London clay
was then deposited, but to no very great thickness.

4. Upon the London and plastic clays as well as the chalk, the
crag was next accumulated in sandbanks, produced by the tidal waters,
and around projecting masses of chalk.

5. While the crag still lay beneath the sea, a violent catastrophe

Geological Society. 117

broke up many of the secondary strata, from the chalk to the lias in-
clusive, and the debris thus produced, together with numerous masse*
of ancient rocks, was spread by a rush of water over the surface of the
tertiary formations and the chalk, in some places to a depth of 400
feet, constituting the beds of drift clay,&c, which occupy so great an
area in Suffolk.

6. Previously to this diluvial action, and after it, the rivers of the
then dry land bore to the sea, animal and vegetable remains, vestiges
of which occur on the Norfolk coast and elsewhere.

7. The climate of this part of the globe was at that era different
from the present.

8. After this period, and probably in prolongation of the first great
catastrophe, a series of shocks acting from below, shattered the surface
and gradually elevated the whole district, till the crag attained the
height of nearly 100 feet above the level of the sea; and by this
movement were produced the valleys or lines of fissure, through which
the drainage of the county is effected.

9. No great convulsions have since taken place.

10. By the action of springs, and the constant battering of the sea,
the superficial contents of the London clay and crag have been re-
duced several miles, vestiges of their former extent being traceable in
rocks and sandbanks nearly always submerged.

1 1. By the set of the tides vast accumulations of shingle and sand
have been formed at projecting points, protecting in some places the
cliffs from further destruction ; but at Harwich harbour they have
blocked up the ancient estuary, and compelled the Stour and Orwell
to form a new outlet.

1 2. The average amount of annual degradation of the coast is about
two yards in breadth ; and in consequence of the conformation of the
ridges of crag and London clay, the cliffs will gradually diminish into
a low sandy shore. The period estimated by Mr. Clarke for effecting
this destruction is another century.

A paper "On the raised beaches of Saunton Downend and Baggy
Point," by the Rev. David Williams, F.G.S., was then read.

The first of these breaches extends from B rami ton Burrows to Down-
end Point ; the other on the N. coast of Croyd Bay, from near the
limekilns to half way to Baggy Point. These beaches were described
in the paper read by Professor Sedgwick and Mr. Murchison on the
14th December, 1836*; and Mr. Williams in this paper fully agrees
with the conclusions drawn by those authors, relative to the beaches
having been raised.

In addition, however, to the proofs afforded by the abundance of re-
mains of existing British marine shellsintheseaccumulations, cemented
together by calcareous infiltration into a tough sandstone, he stated
that he had discovered in many places, from 6 to 10 feet, above the tidal
level, and at the line of contact of the beaches with the old slate rocks
of the district, countless Balani attached to the surface of the latter,
but so firmly entangled in the substance of the former as to be sepa-
rated with its fragments. A large granite boulder also rests on the
* See our last volume, p. 477.

118 Zoological Society.

slate, a .d is involved in the sandstone above any high-water mark.
In support also of the land having been raised and not the sea de-
pressed, he referred to the submarine forests of Somersetshire, in the
prolongation of the same coast from Blue Anchor to the Parret ; and
argued that their position could not be accounted for by a subsidence
in the sea level, but by an unequal movement of the land.

A communication by Mr. James de Carle Sowerby on his new genus
of fossil shells, Tropceum, was then read.

This fossil is described by Mr. Sowerby as an involute chambered
shell with sinuated septa; the whorls free, sometimes very distant;
siphon in the external margin. The natural place of the genus is be-
tween Hamites and Scaphites, and the shells which may be grouped
with Tropaeum, have been hitherto ranked as Hamites, but have no
sudden bend which maybe compared to a hook. The species hitherto
found have been obtained from the gault and green sand. The
species ( Tropceum Bowerbankii) described in the paper was obtained
by Mr. Bowerbank in the Isle of Wight, and was found in the lower
green sand on the sduth side of the Island.

ZOOLOGICAL SOCIETY.
Nov. 22, 1836 {continued).
The following observations on a species of Glaucus, referred to
the Glaucus hexapterygius, Cuvier, by George Bennett, Esq., F.L.S.,
Corresponding Member of the Zoological Society, Surgeon and
Superintendent of the Australian Museum at Sydney, New South
Wales, were read.

" On the 20th of April, 1835, during a voyage from England to
Sydney, New South Wales, in latitude 4° 26'*N., and longitude 19°
30' W., with light airs and calms prevailing at the time, about 3
p.m., a number of damaged and perfect specimens of the Glaucus
hexapterygius, Cuv., were caught in the towing net. On being im-
mediately removed from the net and placed in a glass of sea water,
they resumed their vital actions and floated about in the liquid ele-
ment, exhibiting a brilliancy of colour and peculiarity of form,
which did not fail to excite the admiration of the beholders.

" The back of the animal, as well as the upper surface of the fin9
and digitated processes, and the upper portion of the head and tail,
was of a vivid purple colour, varying occasionally in its intensity ;
appearing brighter in colour when the animal was active or excited,
and deeper when remaining floating tranquilly upon the surface of
the water. The abdomen, and under surface of the fins, are of a
beautiful pearly white colour, appearing as if it had been enamelled.
The usual length of my specimens, measured from the extremity of
the head to the tail, when extended floating upon the surface of the
water, was If inches ; sometimes one or two lines more or less.
The body of the animal is subcylindrical, terminating in a tail, which
gradually becomes more slender towards the extremity, until it
finally terminates in a delicate point. The head is short, with very
small conical tentacula in pairs ; two superior, and two inferior ;
three (and in G. octopterygius, Cuv., four) branchial fins on each

Zoological Society. 119

side, opposite, palmated, and digitated at their extremities; the num-
ber of digitations, however, varying ; and the centre digitations are
the longest; the first branchial fins, those nearest the head, are
larger and denser than the others. The mouth is armed with bony
jaws; the body is gelatinous and covered by a thin and extremely
sensible membrane.

" These little animals were very delicate and fragile in their struc-
ture, and although many, indeed, I may say numbers, were caught,
yet very few in comparison were found to be in a perfect condition,
some being deficient in one, two, or more fins, and others being com-
pletely crushed. Not one of the specimens caught on this occasion,
or during the voyage, had the silvery line or streak running down
the back, from the head to the extremity of the tail ; branching off
also to the fins and along the centre of each of the digitations. Seve-
ral Porpitte were also captured in the net at the same time with
these animals, and serve as food for them.

" It caused much regret to see the change death produced in the
beauty of these interesting little animals, and all means of preserving
them were found to be useless. When placed in spirits, the digits
of the branchial fins speedily became retracted, the beautiful purple
gradually faded and at last disappeared, and the delicate pearly white
of the under surface of the body and fins peeled off and disappeared ;
thus did this beautiful mollusk become decomposed in less than the
space of an hour. Some mollusks quickly lose their colour after death,
but retain their form for a long time ; but these speedily change
after death, both in form and colour, and the beauty before so much
admired perishes never to be regained.

V When taken in the hand, the under surface of the animal soon
becomes denuded of the beautiful pearly white it previously had,
and at that time appears like a small transparent bladder, in which
a number of air-bubbles are observed, together with the viscera. On
the abdomen being laid open, a large quantity of air-bubbles escaped,
and perhaps a query may arise how far they assist the animal in float-
ing upon the surface of the water?

" The figure of Glaucus hexapterygius in Cuvier's work ' Sur les
Mollusques,' is tolerably well executed, but no engraving can convey
to the beholder the inconceivable delicacy and beauty of this mollusk;
in the engraving alluded to, there is an inaccuracy at least as compared
with the specimens before me, — in the digitated processes of the fins
not being sufficiently united at the base ; in the living specimens
before me, they were united together at the base, and then branch-
ing off became gradually smaller until they terminated in a fine
point. Again, in the engraving in Cuvier's work, the anal orifice is
placed on the right side, whereas in my specimens it was situated
on the left ; for in all the specimens I examined, I found the anus
was disposed laterally and could be plainly distinguished situated on
the left side of the animal, a little below the first fin. This I con-
sider also the orifice of generation, as in some of the specimens ex-
amined, a rather long string of dots resembling ova were seen to
protrude from it. One of the animals discharged from this orifice a

120 Zoological Society*

large quantity of very light brownish fluid; this no doubt was the
faces.

" But few of these animals were caught after the 20th until the
24th of the same month, in latitude 2° 26' N., longitude 19° 51' W.,
when having light airs from S. by E., nearly calm ; in the morning
a great number were seen floating by the ship, and it was not diffi-
cult, by aid of my towing-net, to capture as many as I required, for
they swam very superficially upon the water. The whole of those
taken proved to be of the same species (G. hexapterygius) as those
before caught. I again placed several of the specimens in a glass
of sea water; they were full of life, sometimes moving about, not
very briskly, however, — and at other times remaining floating upon
the surface of the water, merely gently moving the fins. As they
floated upon the surface of the water in the glass, the sides of the
head, back, tail, fins, &c, exhibited at the time a light silvery blue
colour, which was admirably contrasted with the deeper blue of the
upper surface, and falling into the elegant pearly or silvery white of
the under surface of the animal, displaying an exceedingly rich and
elegant appearance. Often, when at rest, the animal would drop one
or more of the fins, but on touching them, they would be immediate-
ly raised to the former position, and that organ was turned back as
if to throw off the offending object, followed at the same time by a
general movement of the whole body. On touching the animal upon
the back, it seemed to display more sensitiveness in that than in any
other part of the body, judging from the effects produced, in com-
parison with similar experiments on other portions of the body ; for
instance, the centre of the back was touched lightly and rapidly with
a feather; which caused the little creature to sink as if under the
pressure of the touch, throwing at the same time the head, tail, and
all the fins upwards, followed by a general distortion of the whole
body of the animal, as if the gentle touch had been productive of
severe pain. I invariably found every part of the upper surface of
the body very sensitive when touched, and displayed a general move-
ment of uneasiness throughout the whole of the body of the crea-
ture.

" These creatures have a peculiar manner of throwing the head
towards the tail, and flouncing the tail towards the head, when they
are desirous of removing any object of annoyance. It is at that time
these animals seem to recover from their torpidity, and evince the
greatest activity in their movements. When much annoyed, they
throw the body about with great activity, coiling up the head, tail,
fins, &c, in a somewhat rotundiform position; and if the tormenting
object is not removed, dasji out again in full activity of body, then
return to the rotundiform position, and there remain for a short
period apparently exhausted by their efforts. But on the cessation
of the irritating cause, the animal quietly resumed its original po-
sition, perhaps dropping one or two of its wearied fins according
as its own sensations of ease or comfort might dictate.

" When nothing irritated this tender mollusk, it would remain
tranquilly floating upon the surface of the water with scarcely any

Zoological Society. 1 2 1

movement but that which proceeded from the undulating movements
of the digitated extremities of the fins, as well as an occasional
slight twisting motion of the same organs.

" I felt much interest in the beautiful display of a circulating fluid
on the dorsal surface of these animals, which was afforded me by
the assistance of a microscope. Through the semi-transparent mem-
brane of the back, a fluid could be readily perceived close to the sur-
face, evidently flowing in two directions, one taking a course down-
wards, and the other returning upwards; but I was unable to di-
stinguish two distinct vessels for these separate actions.

" These animals seemed to be very torpid in their movements,
although sometimes, when floating upon the water, they would
be seen busily engaged in moving their fins about, but those actions
were soon suspended and their fins were suffered to hang lazily
down, as if fatigued with the short exertion, which did not move
them one inch about the glass of water ; and even when the little
indolent creatures did take the trouble to move themselves from one
side of the glass to the other, it was effected by a tardy motion,
stirring themselves first with one fin and then with the other, ac-
cording as circumstances might require.

" I placed some small specimens of Porpita in the glass of water
containing the Glauci, to observe if they would attack them; for
some time one of the Glauci was close to a Porpita and was even
annoyed by the tentacula of the latter touching its back, yet the
Glaucus bore this, although with the usual characters of impatience,
yet without attempting to attack it. At last it seized the Porpita
between its jaws, and by aid of a powerful lens, an excellent oppor-
tunity was afforded me of closely watching the devouring process,
which was effected by an apparently sucking motion; and at this
time all the digitated processes of the fins were floating about, as at
other times when the animal was at rest; but I did not observe, in
one single instance, that they were of any use to the animal, either
to aid in the capture or to securely hold their prey when in the act of
being devoured ; for the animal seems to depend merely upon the
mouth in capturing its prey ; as in this and other instances, which
I had opportunities of observing, they seized their prey instantly
with the mouth, and held it by that power alone, whilst by a kind
of sucking motion the prey was devoured. The digitations may
therefore only be regarded as appendages to the fins to aid the ani-
mal perhaps in the direction of its movements, as it was observed
that they turned and twisted them about during the progressive mo-
tion, (that is, when this tardy animal is pleased to progress, which
appeared to me very rarely to meet with its inclination,) as if in some
way or other to direct the movements of the animal.

" The Glaucus, after eating the tentacles and nearly the whole of
the soft under surface of its prey, left the horny portion, and re-
mained tranquilly reposing upon the surface of the water after its
meal, the only motion visible in the animal being the playing of the
digits of its fins. The mutilated remains of the Porpita sank to the
bottom of the glass.

Third Series. Vol. 1 1. No. 65. Supplement, July 1837. R

1 22 Zoological Society,

" Soon after, another Glaucus began a devouring attack upon an-
other Porpita which had been placed in the glass, eating a little of
it and then ceasing after a short meal, occasionally renewing the at-
tack at short intervals. On examining the Porpita, which had been
partially devoured by the ravenous Glaucus, I found the disc had
been cleared of the tentacles and other soft parts ; a small part of the
fleshy portion only remaining upon the disc. Only one part of the
horny disc exhibited any injury, and that appeared to be the place
where the animal was first grasped by the Glaucus.

" When any of these animals came in contact with another in the
glass, they did not display any annoyance, or coil themselves up,
nor did they evince any savage propensities one towards the other ;
and they would often float about, having their digitated processes in
contact one with the other, without exhibiting any signs of annoy-
ance ; even when placed or pushed one against the other, they did
not manifest any irritation, but remained undisturbed as in their
usual moments of quiet repose.

" On the back of the animal being seen in a strong light, a black
line could be discerned on each margin, and passing down the centre
of each fin, and sometimes varied in having two black lines on the
upper part of one fin, although the opposite fin may display but one.
" The margin between the falling of the purple colour of the back
into the silvery white of the abdomen often exhibited beautiful tints
of a golden green ; but these variations were probably produced by
the effect of different rays of light.

"These animals soon perished ; I could not preserve them for any
length of time in the glass of sea water, although the water was
changed as often as it was thought necessary ; the digitated pro-
cesses of the fins were observed to shrink up on the death of the
animal, and the process of decomposition rapidly took place, the
whole body becoming a shapeless mass, having a bluish colour of
deadly hue for a short period, and then became of a blackish or
brownish black colour. I have seldom seen a gelatinous animal
which appeared so firm whilst in the water, that proved so speedily
to decompose when removed from it ; even the beautiful purple of
the back, the silvery or enamel of the abdomen, and the silvery blue
of the sides, all speedily vanish, indeed instantly disappear, upon the
death of the animal, as if it had been washed off; the expansive, de-
licate, and beautiful fins and digitated processes are no longer seen ;
they shrank up to nothing.

" Even on taking the animal alive out of the water and placing it
upon the hand, that instant almost, from its extreme delicacy, it was
destroyed : the digitations of the fins fell off, the least movement
destroyed the beauty of the animal; it speedily lost all the deep
purple and silvery enamelled tints, and became a loathsome mass.
Thus do we too often find animals beautiful in external adornments,
curious in their habits and organization, and calculated in every re-
spect to supply us with inexhaustible sources of intellectual gratifi-
cation, doomed speedily to perish ; brief is the period allotted to
them in the busy theatre of animated existence; but doubtless, with

Zoological Society, 1 25

the gift of existence, they have received from the bounteous hand of
their Creator, the means of enjoying their fleeting lives.

" To place these little animals in the glass of water from the towing
net without injury to their delicate structure required care ; so that as
soon as they were captured in the net attached to the meshes, they
were not handled, but carefully washed off, which was effected by
dipping the meshes in the glass of water, when the animal soon
detached itself without sustaining any injury, and floated in the
water.

" Although these animals are so fragile, so easily destroyed on
being taken out of their natural element, yet they fling themselves
about in the water without sustaining any injury, without even the
loss of any of the digitated processes of the fins ; yet when there is
much movement of the water in carrying the glass from one place
to another, they are evidently disturbed and restless, and the fins
are dropped; if therefore, a slight motion of the water disturbs them,
what can become of these delicate mollusks during tempestuous
weather ? can they be similar to the delicate Ephemeris, doomed to
live merely for the space of a day and perish in myriads ? From the
immense number seen only from the ship — and how many myriads
more extended beyond our range of vision ! — it conveyed to the mind
some idea of the profusion of living beings inhabiting the wide ex-
panse of ocean, and a feeling of astonishment at the inconceivable
variety of forms and constructions to which animation has been im-
parted by creative power.

" The tail of this animal has been described as resembling that
of a Lizard: the comparison is good, not only with regard to form,
but also, with perhaps a little more flexibility of motion, when in
action. Sometimes the animal throws its tail up to the body, as if in-
tended to brush off any annoying object, and at other times, it has
been observed to turn the head towards the side as if for a similar
purpose. It seems, in the action of eating, to resemble a Cater-
pillar.

" No more of these animals were seen until the 15th of May at
10 p.m., when in lat. 24° 18'*5, long. 31° '"01 W., moderate
breezes and fine weather ; a number of Glauci were captured as well
as Porpita ; some of the latter had been partially devoured, and in
some only the horny disc remained; this, there was no doubt, from
the previous knowledge of the carnivorous propensities of the
Glaucus, was their work, more especially as we had positive proof
that tribes of them were wandering or prowling about the ocean to-
night. This was the last time during the voyage the Glauci were
captured.

" From these animals devouring the Porpitte, we had positive
evidence of their carnivorous habits, independent of the structure of
the jaws ; and the tentacula of the Porpita were no protection against
their enemies; indeed, these appendages were first devoured and the
horny disc was alone left, in many instances being quite picked
clean ; from this circumstance we may infer, that the horny discs of
the Porpita. and Vclella, which previously, and for the last four days

R2

124 Zoological Society.

were found in the net, were the remains of those which had been de-
voured by the Glauci or similar carnivorous mollusks, among which
we may with safety include (from the structure of its jaws, and
from often capturing it attached to Velella,) the inhabitant of the
Janthina fragilis or violet shell.

" The more we pursue the investigation of the actions of living
objects, the more we see of the unbounded resources of creative
power ; and, after all our reasoning, must conclude that some wise
purpose, though dimly perceptible to our imperfect understandings,
is no doubt answered by this great law of organic formation, — the
law of variety."

Mr. Ogilby called the attention of the Meeting to the various
preserved specimens of Antelopes then exhibited, and made the fol-
lowing observations on some hollow-horned Ruminants.

" In arranging the Society's collection subsequent to the late re-
moval from Bruton Street, the following rare or undescribed species
of Ruminants were observed, which it is thought proper to bring
under the public notice of the Society.

" 1. Ixalus Probaton. A single skin of the very anomalous animal
to which I propose assigning this name, was presented to the So-
ciety by Dr. Richardson, and has been considered as the female of
A. Furcifer, from which, however, it differs in some of the most
important characters. Of its origin there can be no reasonable
doubt ; it was contained in the same box with the skins of A. Fur-
cifer, and other animals obtained by the celebrated zoologist just
mentioned, during Capt. Franklin's memorable expedition, and
the hay with which it was stuffed contained numerous small locks
of the very peculiar hair of A. Furcifer. The specimen is a male
about the size of a fallow Deer, the length from the nose to the
end of the tail being 4 feet 10 inches. The head is 9^ inches long,
the tail, 5£ inches; and the ear, 3| inches. Though the skin is
that of an adult individual, as is proved by the incisors, which are
all of the permanent class and considerably worn down, the head is
without horns, having only two small, naked, flat scales, in the po-
sitions usually occupied by these organs ; yet the bones of the skull
remain beneath, and the specimen is unquestionably the spoil of a
male animal. In form, as well as size, the animal resembles the fal-
low Deer (Cervus Dama). The colour is a uniform pale reddish
brown above and on the outsides of the members ; the breast, belly,
and inner face of the anus and thighs are grayish white ; the lower
part of the cheeks, the lips and beneath the chin are of the same
colour, but the whole throat or under surface of the neck is pale
reddish brown, like the back and sides. The tail is covered above
with short reddish hair like that of the body, but it is perfectly naked
beneath, and in form and length resembles the tail of some species
of Deer (Cervus). The nose is hairy like that of a Goat: the animal
is furnished with lachrymal sinuses of considerable size, opening by
very obvious apertures of a circular form ; it has inguinal pores and
two teats, as in the common Antelope (A. Cervicapra); large spurious
hoofs, and no appearance of scopee or knee-brushes either on the

Zoological Society. 125

anterior or posterior extremities. These characters will not permit
it to be associated with any known group of Ruminants. That it is
not merely a Deer which has cast its horns, is proved by the absence
of the pedestals which support these organs in the solid-horned Ru-
minants, as well as by the hairy lips, two teats and inguinal pores :
neither can it be a Sheep or a Goat, as is evinced by the lachrymal
sinuses, inguinal pores, and the length and form of the tail, which,
in the wild species of these genera, is nearly tuberculous. The sup-
position of its being the female of A. Furcifer is disproved by the sex
of the specimen ; in other respects, the existence of large spurious
hoofs shows plainly enough that it has no affinity to that animal.
There is but one other supposition : may it not be a species of An-
telope allied to the typical group of that genus? and may not the
abortive horns of the present specimen be the result of some acci-
dent ? This may certainly be the case ; the other characters of the
specimen agree with those of the common Indian Antelope, and if the
animal should eventually prove to belong to that genus, it may bear
the specific name of A. Ixalus, which the classical scholar will re-
cognise as the name of an undetermined species of Ruminant men-
tioned in the Iliad.

" 2. Antilope Eurycerus. Of this magnificent and hitherto unde-
scribed species, two pairs of horns, one attached to the skull, the
other to the integuments of the head, have long existed in the So-
ciety's collection. Their origin is unknown, but I have reason to
believe that they come from Western Africa. Their length in a
straight line is 2 feet If inch; on the curve, 2 feet 7| inches;
their circumference at the base is 10 inches; their distance at base
1 inch, and at the points 1 1 inches. In form they bear some re-
semblance to those of A. Strepsiceros, being wrinkled as in that spe-
cies, and having a prominent ridge on their posterior face ; but they
form only one spiral twist instead of two, and their direction through-
out lies in the plane of the forehead, whilst in the Koodoo these two
planes form an angle of about 100°. The characters of the skull are
likewise similar to those of the Koodoo, but it is broader and larger
than in that animal. The points of the horns are of an ivory colour.
The animal has a large muzzle, but is without lachrymal sinuses ; it
has a white band across the face, immediately under the eyes, and two
white spots on each cheek. All these characters are distinctive of
the natural group which includes the Koodoo, the present species,
the Boshbok, the Guib, and the beautiful species mentioned by Mr.
Bennett (Proc. Zool. Soc, 1833, p. 1.) which is a real Antelope, and
which I hope shortly to have an opportunity of describing in detail
under the name of A. Doria, as a friend, who has connexions with the
West Coast of Africa, has kindly undertaken to procure me skins.

" 3. Antilope Philantomba. Two females of this minute specieslived
for some time in the Society's Gardens : they were brought from
Sierra Leone and presented by Mr. McCormick. Mr. Rendall, who
saw them with me at the Gardens, assured me that they were the
Philantomba of the Sierra Leone negroes. The larger and older spe-
cimen has small horns about 1 \ inch long, bent slightly forwards

1 26 Zoological Society.

and surrounded at the base with 5 or 6 small rings : the species is
distinguished from the pygmy Antelope of the Cape by its longer tail
and ears, the latter clothed with white hair on the inside, by the
darker mouse -colour of the body and the uniform hue of the legs,
which instead of being sandy red as in the Cape species, are of the
same colour as the body, only rather paler. But for the circumstance
of the female possessing horns, I should have been inclined to iden-
tify this animal with the A. Maxwellii of Col. Smith.

"4. Antilope Sumatrensis. This species and A. Thar were exhibit-
ed together for the purpose of pointing out the similarity of their
zoological characters, and correcting a mistake into which Messrs. F.
Cuvier, Desmarest, and Col. Smith have fallen with regard to the
former species. According to these zoologists the Cambing Out an
(A. Sumatrensis) possesses both the lachrymal sinus and the longi-
tudinal gland on the maxillary bone, which distinguishes the Duy-
kerbok {A. Mergens) and some other Antelopes: in reality the lachry-
mal sinus is sufficiently distinct, but there is not the slightest trace
of any maxillary gland. The same zoologists represent the female
Cambing as being without horns and having only two teats : the spe-
cimen exhibited, a young female, had tolerably large horns and di-
stinctly showed four teats, thus agreeing in all respects with the adult
female Thar with which it was compared.

"5. Antilope palmata. Colonel Smith has described the horns of
this species from an imperfect pair preserved in the Museum of the
College of Surgeons, but was undecided whether it should be con-
sidered as a distinct species or only a variety of the Prongbaick (A.
Furcifer). The present perfect pair, with the skin of the head at-
tached, goes far to prove the specific distinction, but the habitat is
widely different from that assigned by Colonel Smith. The speci-
men came from Mexico, where Dr. Coulter informs me it is sufficient-
ly common. The horns are twice or thrice as large again as those of
A. Furcifer, and instead of preserving a tolerable degree of parallelism,
as in that species, spread widely, and are much hooked at the points.
The face also is of a very dark brown colour, whilst in A. Furcifer it
is of the same light fawn as the upper parts of the body."

Mr. Gray exhibited a specimen of Argonaut with an Ocytho'e
from the Cape of Good Hope, and stated that as the subject had
been brought forward at the last meeting, he was induced to remark
that every time he considered it, and compared it under its various
bearings with the relations of other Molluscans and their shells, he
was more and more inclined to believe that the animal found in the
shell of Argonauta was a parasite. He gave the following reasons
for this belief.

" 1 . The animal has none of those peculiarities of organization for the
deposition, formation, and growth of the shell, nor even the muscles
for attaching it to the shell, which are found in all other shell-
bearing Molluscans ; instead of which it agrees in form, colour, and
structure with the naked Mollusca, especially the naked Cephalo-
pods.

" 2. The shell, although it agrees in every respect with the shells

Zoological Society. 127

of other Molluscans in structure, formation, and growth, is evidently
not moulded on the body of the animal usually found in it, as other
shells are ; but exactly agrees in every point (except in the form of
the spire), with the shell of Carinaria, which coincided with the other
Molluscans in all these respects.

" 3. The body of the animal does not appear to have the power of
secreting calcareous matter, for it does not, like all the Mollusca
which have that power, secrete either a solid deposit or distinct septa
to adapt the cavity of the shell to the increase of the body, nor does
it cover over with calcareous matter any sand or other extraneous
bodies which may have accidentally intruded themselves between the
mantle and the shell, but leaves the sand, which is often found mixed
with the eggs, free, without taking any means to prevent it from
irritating the skin.

" 4. The young shell of the just hatched animal which forms
the apex of the shell at all periods of its growth, is much larger
(ten times) than the eggs contained in the upper part of the cavity of
the Argonaut."

Mr. Gray further stated, that he does not think that any inference
can be drawn in favour of the opinion that the Ocythoe forms the
shell, from either of the three arguments which have been produced
in favour of that hypothesis, which he then examined in detail.

"5. He believes that Poli must have been misled when he thought
that he had discovered the animal in the egg of an Ocythoe covered
with the ' rudiment of a shell,' because all the Molluscans which
he has seen in the egg (Cephalopods as well as others) were covered
with a well-developed shell, even before all the organs were deve-
loped, and the figure which Poli gives of the rudiment does not
agree with the nucleus found on the apex of the shell of the Argo-
nauts. Unfortunately, none of the eggs of the Ocythoes that have
been examined by other observers have been enough developed to
show the foetal animal.

"6. The different species of Argonauta are said to be inhabited by
different species of Ocythoe; but allowing this to be the case, it
only proves that each of these genera have local species : the same
may be observed with respect to the Hermit Crabs, without proving
anything in favour of their being the framers of the shell they live
in.

" 7. That though some specimens of Ocythoe preserved in their
shells are marked with cross grooves resembling the grooves on the
shell, yet these grooves are only formed by the pressure of the dead
animal against the shell ; for the specimens of the animal which are
found out of the shell, or which are taken out of the shell while re-
cent, are always destitute of these grooves, or of the compressed
form of the cavity of the shell. That some specimens which he
had received from the Cape (of which that now on the table was
one), which had been packed on their sides, had the upper side
of the animal smooth and rounded, and the lower flat, and curved
like the shell on which it was pressed by its own weight ; while a
specimen which he had received from the Mediterranean packed

1 28 Zoological Society.

erect, with the mouth upwards, so that the animal was equally pressed
against each side of the shell, was flattened and curved on each side,
like the specimen examined by M. Ferussac."

Mr. Gray also stated that, so far from the animal using the finned
arms as sails, they were the means by which it retained itself in the
shell ; and he further "observed, that it was very difficult to distin-
guish the species of Argonauta, as they varied greatly in shape, and
that on a comparison of many specimens, he had found that the
presence or absence of the spines or ears at the back of the mouth
were of no importance as a specific character, specimens of each of
the recorded species having this process developed only on one or the
other side.

The Chairman, (Mr. Owen,) after premising some observations
on the diseases to which the mortality of the larger feline animals
in the Society's Menagerie was attributable, proceeded to read the
following description of two Entozoa infesting the stomach of the
Tiger, (Felis Tir/ris, Linn.,) one of which forms the type of a new
genus of Nematoidea.

" I received a few days ago, from the Medical Superintendent of
the Society's Menagerie, a portion of the stomach of a young Tiger
(which died of rupture of the aorta), exhibiting on the internal or
mucous surface what were considered to be scrofulous tumours.
They were five or six in number, of a round and oblong form, vary-
ing in size from half an inch to two inches in the largest diameter,
and the largest of them projecting about half an inch from the plane
of the inner surface : they made no projection externally. The mu-
cous membrane covering the smaller tumours was puckered up into
minute reticulate ruga: the surface of the largest tumour was smooth.
On wiping away the tough thick mucous secretion from the tu-
mours, and examining more closely their surface, two or three orifices
presented themselves in the larger, and a single orifice in each of the
smaller tumours. These orifices conducted to irregular sinuses which
were the nidi of two kinds of Nematoid Entozoa, some measuring
nearly an inch in length and a line in thickness; the others being
more minute, not exceeding 5 lines in length, and about ^ of an
inch in diameter. Only a pair of the larger Entozoa were found in
each of the three largest tumours ; the smaller species existed in
countless numbers.

" Before proceeding with the description of the worms, I may
briefly conclude the history of the tumours by observing that they
were composed of condensed accumulated layers of the sub-mucous
cellular tissue, presenting a flat surface next the muscular coat, to
which the larger tumours firmly adhered, and projecting with a
rounded convexity towards the cavity of the stomach, where the si-
nuses opened and terminated. They did not contain any of the
caseous secretion characteristic of struma, but were most probably
caused by the irritation of the Entozoa.

" The dimensions of the larger Entozoa above given are those of
the female : the male is about one fourth smaller. In both sexes the
body is slightly attenuated at the two extremities ; the caudal ex-

Zoological Society. ■ 129

tremity is more inflected and more obtuse in the male ; the oral ex-
tremity in both is obtuse and truncate.

" The surface of the body appears to the naked eye to be mi-
nutely striated transversely: it is variegated by the white genital,
and amber-coloured digestive tubes appearing through the transparent
integument. When* examined with a lens of half-inch focus, the
anterior two-thirds of the body are seen to be covered with circular
series of minute reflected spines, which, viewed with a still higher
power, present three distinct points, one large one in the middle and
two small lateral ones.

" The mouth is surrounded by a tumid circular lip armed with six
or seven circular rows of well-developed spinous processes of a simi-
lar complex structure to those on the body. The oral orifice itself
presents the form of a vertical elliptical fissure, bounded on each
side by a jaw-like membranous fold or process, the anterior margin
of which is produced in the form of three straight horny points or
processes, directed forwards. These lateral processes can be pro-
truded beyond the circular lip by compressing the smooth spineless
skin behind the latter; and the elasticity of the structure causes them
to be again retracted on remitting the pressure.

" The vulva is situated at the junction of the middle and posterior
thirds of the body ; the anus in the female is in the form of a trans-
verse semilunar fissure immediately behind the obtuse posterior apex,
and on the concave side of the inflection.

" The anus of the male, from the anterior part of which a single
slightly-curved intromittent spiculum is protruded, is surrounded by
eight distinct pointed papilla, three of which are placed in a vertical
row on each side, and two smaller ones at the lower boundary of
the common opening to the rectum and male gland.

" On comparing this Nematoid worm with those already described,
it approaches most nearly to some species which are referred by
Rudolphi to the genus Strongylus, as the Strongylus trigonocephaly,
R., (Hist. Entoz. ii. pi. I. p. 231.,) in which species the 'Bursa maris
subglobosa, biloba, multiradiata,' presents an approximation to the
structure of the external male organs above described, in which the
eight tubercles surround the opening somewhat after the manner of
rays. But on pursuing the comparison we find that here the re-
semblance ceases : there is no subglobose bilobed sheath to the in-
tromittent organ in the species here described ; the head is sur-
rounded by a circular instead of a trigonal lip ; the Strong, trigono-
cephalus is placed by Rudolphi in the section c, ore nudo, while
the armature of the mouth, in the present species, is so remarkable,
as to induce me to regard it as the type of a new genus, which I pro-
pose to denominate Gfiathostoma*.

" Gen. Char. Corpus teres, elasticum, utrinque attenuatum. Caput
unilabiatum, labio circulari tumido integro ; os emissile, processibua
corneis maxilliformibus duobus lateralibus denticulatis. Genitale
masculum spiculum simplex, ad basin papillis circumdatum.

• yv*6o; maxilla, irrouec Of.

Third Series. Vol. 11. No. 65. Supplement, July 1837- S

130 Zoological Society.

" Sp. Gnath. spinlyerum. Gnath., capite truncato, corpore seriebus
plurimis spinulorum armato.

" The generic difference indicated by the external peculiarities of
the Entozoa above described, is confirmed by the internal anatomy,
which presents some peculiarities which appear not to have been
hitherto detected in the class Entozoa : I refer more particularly to
a distinct salivary apparatus, conformable to that which exists in the
Holothuria and other Echinodermata. This apparatus consists of four
elongated straight blind tubes, each about two lines in length, which
are placed at equal distances around the commencement of the ali-
mentary canal, having their smaller extremities directed forward,
and opening into the mouth, at the base of the lateral tridentate
processes, and their closed obtuse ends passing backwards into the ab-
dominal cavity. When examined with a lens of \ inch focus, the
parietes of these salivary tubes present very distinct oblique or spiral
decussating fibres ; their contents are semi-pellucid in the recent
worm, but become opake in spirit of wine.

" The coexistence of these salivary glands with an oral apparatus
which is better adapted for trituration than any that has hitherto
been detected in the Entozoa, is conformable to the laws which re-
gulate the existence and condition of the salivary apparatus in higher
animals; and is highly interesting on that account. The only allu-
sion which I can find to salivary organs in other Entozoa is in Clo-
quet's 'Anatomie de CAscaride Lombrico'ide,' in which he considers the
thickened glandular parietes of the esophagus to serve for an analo-
gous secretion.

" The first portion of the alimentary canal or stomach is about 3
lines in length ; it contains a milk-white substance, and is separated
by a well-marked constriction from the remaining portion, which we
may regard as intestine : this is filled with a pulpy substance of an
amber colour, which grows deeper in tint as it approaches the anus.
The intestine enlarges slightly as it passes backward ; it is wide and
straight : is not tied down to the parietes of the body by mesenteric
filaments as in the Strongylus gigas, &c. ; its surface is irregular, and it
seems to contain a spiral tube or valve, but this appearance arises
from the nature of the internal surface of the intestinal tunics, which
is beset with large regular obtuse lozenge-shaped processes arranged
in alternate longitudinal rows.

" The lateral lines of the body consist distinctly of two vessels,
which project into the interior of the body, being attached by a small
part of their circumference ; and becoming very wide and free near the
head. The dorsal and ventral nervous cords are plainly visible in
the midspace of the lateral vessels. The muscular tunics of the body
are well developed, consisting of external transverse and internal
longitudinal fibres. The latter are lined with a layer of pulpy floc-
culent substance.

" The male organs consist of a slightly-curved slender single
spiculum, projecting from the caudal extremity of the body, as
above described. The base of this spiculum communicates with a
dilated receptacle, 2 lines long, of an opake white colour, which is

Royal Irish Academy. 131

Beparated by a slight constriction from the rest of the seminal tube ;
this is, as usual, single : it is semi-transparent, and gradually grows
smaller to its blind extremity, which is attached by cellular tissue to
the middle line of the ventral surface of the body, half-way between
the two extremities. The whole length of the seminal tube is ten
times that of the entire worm.

" The female organs consist of the vulva, vagina, uterus bicornis,
and oviducts or ovarian tubes.

"From the vulva, the situation of which has been already men-
tioned, the vagina is continued, at first wide, then narrower, and lastly
widening again to pass into the uterus: it exceeds an inch in length.
The two cornua of the uterus are each about \ a line in diameter, and
5 lines in length ; they diminish and are continued without any con-
striction into tne ovarian tubes ; these are of immense proportional
length, each exceeding, by 30 times, the length of the body ; their at-
tenuated extremities or beginnings are not attached to the parietes
of the body; although the coils of the oviducts appear at first sight
to be inextricably interwoven around the intestine, they in reality
cover it in aggregate folds, which are easily separated from the in-
testine, and unravelled/'

Mr. Owen stated in conclusion, that preparations exhibiting the
male and female organs thus unfolded, with the digestive canal and
salivary apparatus, had been deposited in the Museum of the Royal
College of Surgeons.

ROYAL IKISH ACADEMY.

January 9. — Sir William Betham read a letter from the Baron
de Donop, of Saxe Meiningen, on the subject of the alleged dis-
covery of the MS. Translation of Sanconiathon's History of the
Phoenicians, by Philo Biblius.

Sir William' Betham read a letter from Sir John Tobin, of Liver-
pool, respecting the cast-iron ring money found on board the wreck
of a vessel, and exhibited at the meeting of the Academy in Novem-
ber. The following is an extract:

" On the subject of the schooner Magnificent, which was lost
somewhere near Cork some time since ; she was bound to the river
Bonney, or New Calabar, which is not far from the kingdom of Benin.
The trade to these rivers for palm oil and ivory, is cotton goods gun-
powder, muskets, and a great variety of other articles; and among
them maniilas, both of iron and a mixed metal of copper and brass,
which is the money that the people of Eboe and Brass Country, and
all the nations in that neighbourhood, go to market with. On Wed-
nesday next I will send you a manilla of each kind."

Sir John Tobin states the price of the copper manillas to be 105/.
per ton, and that of the cast iron 22/. j the former passes, therefore,
for about five of the latter. They so perfectly resemble the Irish
antique as to be scarcely distinguishable except by the difference of
the material.

Sir William Betham also read a letter from Captain Edward Jones

S2

132 Royal Irish Academy,

to Samuel Hibbert, M.D., which the latter gentleman transmitted to
him, with the sketches there alluded to.

" The annexed two sketches are taken from a cast of the species
of money now at the present day passing current among the Africans.
It so strongly resembles what we saw in Ireland, that 1 thought you
might be interested in a copy of it. Mr. Dyson, who was for some
years a surgeon on board an African merchantman, brought it with
him ; and the first opportunity I shall make inquiries respecting this
and other coin used among the natives. I am told that in the country
they are made of solid gold, as in Ireland."

Sir William Betham also read an extract from a letter from Mr.
Bonomi to T. C. Croker, Esq.

" You asked me for a note on the ring money of Africa ; here it
is. So little has the interior of the country changed in that particular
since the days of the Pharaohs, that to this day, among the inhabitants
of Sennaar, pieces of gold in the form of a ring pass current as money.
The rings have a cut in them for the convenience of keeping them
together j the gold being so pure you easily bend them and unite
them in the manner of a chain. This money is weighed as in the
days of Joseph."

These gold rings are so similar in shape to the ancient rings found
in Ireland, that the sketch of one accurately represents the other.

It is a remarkable fact that the name manilla, which these brass
and iron articles still bear in Africa, signifies money in the Celto-
Phcenician Irish. Main is ' value,' « worth,' and aillech is ■ cattle/
4 household stuff/ or * any kind of property.' So that in this respect
the derivation is similar to that of pecunia from pecus. The manillas
were, no doubt, introduced into Africa by the same people that brought
them to Ireland ; and as the negro nations have changed but little,
if at all, they still pass as money by their old Phoenician name.

The Rev. James H. Todd, A.M., M.R.I.A., Fellow of Trinity Col-
^eSe> gave an account of a discovery made by Mr. John O'Donovan,
of a valuable though imperfect copy, in MS., of the Annals of Kilro-
nan, or Book of the O'Duigenans, a work that had hitherto been
supposed to be lost. It is particularly described in the * Proceedings'
of the Academy, No. 2.

Mr. Petrie exhibited a MS. of the four Gospels, in Latin, of which
he had given an account in a paper read some time since before the
Academy. This manuscript is said to have been that given by St.
Patrick to the first Bishop of Clogher. It is inclosed in a brazen
case, of very curious workmanship, on which the circumstances con-
nected with the gift are represented in highly raised figures.

Professor Lloyd communicated to the Academy the continuation of
his investigations '*■ On the Propagation of Light in uncrystallized
Media."

In the first part of this paper, read on a former evening, the author
had expressed his conviction that the problem of wave-propagation in
bodies was incompletely solved, unless the action of the material
molecules be taken into account. This he has attempted to do in the

Royal Irish Academy. 133

present continuation, confining himself to the comparatively simple
case in which the molecules of the aether and of the body are uniformly
diffused.

The differential equations of motion inferred from these considera-
tions contain, each, the displacements of the molecules of the aether
and of the body, with coefficients depending on the masses and di-
stances of the molecules, the law of force to which they are sub-
jected, and the length of the wave. By a particular method of elimi-
nation, these pairs of simultaneous equations may be reduced each to
a single one, of the simple form which occurs in the case of a single
vibrating medium, the new coefficient being connected with those of
the original equations by an equation of the second degree. The ex-
pression for the displacement, then, is of the same form as in the case
of a single vibrating medium j but the relation between the coeffi-
cients of the time and of the distance, and consequently the velocity
of propagation, will be very different.

The quadratic equation above alluded to expresses the relation of
these coefficients, or, in other words, the relation between the period
of vibration and the length of the wave. When the action of the
molecules of the aether and of the body, inter se, and on one another,
is governed by the same law, this equation is resolvable into simple
factors, one of which only seems to belong to the problem, the other
giving an expression for the velocity of propagation independent of
the length of the wave. The author accordingly proceeds to develop
the former of these formulae, converting the triple sums which it con-
tains into triple integrals, according to the method of ML Cauchy.

Among the consequences deducible from this development is the
following : In the expanded expression for the velocity of propaga-
tion, each term consists of two parts, one of which is due to the
action of the aether, and the other to that of the body. It is not im-
probable that there may be bodies for which the first or principal term
is nearly nothing, the two parts of which it is composed being of op-
posite signs, and nearly equal. In this case the principal part of the
expression for the velocity will be that derived from the second term ;
and, if that term be taken as an approximate value, it will follow that
the refractive index of the substance must be in the sub-duplicate
ratio of the length of the wave nearly. Now, it is remarkable that
this law of dispersion, so unlike anything observed in transparent
media, agrees pretty closely with the results obtained by Sir David
Brewster in some of the metals. In all these bodies the refractive
index (inferred from the angle of maximum polarization) increases
with the length of the wave. Its values for the red, mean, and blue
ray, in silver, are 3866, 3*271, 2*824 j the ratios of the second and
third to the first being *85 and '73. According to the law above
given, these ratios should be *88 and '79.

Professor MacCullagh made a verbal communication on the pro-
bable nature of the light transmitted by the diamond and b}' gold leaf.
He conceives that as there is a change of phase caused by reflexion
from these bodies, so there is also a change of phase produced by re-
fraction ; the change being different according as the incident light

13* Jioj/al Irish Academy.

is polarized in the plane of incidence, or in the perpendicular plane.
Consequently, if the incident ray be polarized in any intermediate
plane, the refracted ray should be ellipticallv polarized ; and on ex-.
amining the light transmitted by gold leaf, this was found to be the
case. Of course the same thing is true of the light which enters the
other metals, and which is subsequently absorbed. The same remark
explains the appearance of double infraction in specimens of the
diamond which give only a single image j and it is likely that other
precious stones will be found to possess similar properties. Mr.
MacCullagh has obtained a general formula for ihe difference of phase
between the two component portions of the refracted light, one po-
larized in the p'ane of incidence, and the other perpendicular to it.
He finds from this formula, that the difference of phase, which is no-
thing at a perpendicular incidence, increases until it becomes equal
to the characteristic at an incidence of 90°; and when the light emer-
ges into air, the difference of phase is doubled. The formula has not
yet been submitted to the test of experiment.

Mr. MacCullagh then read a paper " On the Laws of Crystalline
Reflexion and Refraction.*"

In this paper the solution of the following problem is given for the
first time : — Supposing a ray of light, polarized in a given plane, to
fall on a doubly refracting crystal, it is required to find the plane of
polarization of the reflected ray, and the proportion between the am-
plitudes of vibration in the incident, the reflected, and the two re-
fracted rays.

The constructions to which the author has been led by his theory
are extremely simple, and may be explained most easily by referring
to a paper which he has already published in the Transactions of the
Academy, vol. xvii. pp. 23 1, 252. To avoid circumlocution, he uses
the term transversal, to denote a right line parallel to the plane of
polarization of a ray, and perpendicular to the direction of the ray
itself. When ihe transversal is spoken of as a finite magnitude, its
length is understood to be proportional to the amplitude of the vibra-
tions in the polarized ray. Let o (as in the place just referred to)
be the point of incidence on the crystal, and ot, ot' the directions
of the two refracted rays, the points t, t' being on the wave-surface.
Corresponding to the points r and t' on the wave-surface, there are
two other points, p and m, on a second surface, which is reciprocal to
the wave-surface. The points p and m are derived from the points
t and t' by an easy rule, which is given in the place before cited.
Now if we wish to find in what direction the incident ray must be
polarized in order that the ray o t' may disappear, let us draw, thiough
the point o, a plane a perpendicular to the plane otp, and parallel
to the right line tp, which joins the corresponding points t, p. This
plane a will intersect the planes of the incident and reflected waves
in two right lines, which will be the transversals of those waves ; so
that if the incident ray or wave be polarized parallel to the first in-

• Papers on this subject by Prof. MacCullagh will be found in Lond.
and Ediub. Phil. Mag., vol. viii. p. 103, vol. x. p. 42.— Edit.

Royal Irish Academy. ] 35

tersection, the reflected ray will be polarized parallel to the second
intersection, and there will be only a single refracted ray ot. A
right line drawn through the point o, perpendicular to the plane otp,
will lie in the plane a, and will be the transversal of the refracted
ray ot ; and if, measuring from the point o, the lengths of the three
transversals represent the amplitudes of the respective vibrations, the
transversal of the refracted ray ot will be the diagonal of the parallel-
ogram, whose sides are the transversals of the incident and reflected
rays. The problem is, therefore, completely solved in this case, and
it is obvious, that a construction precisely similar will apply to the
other case, in which or' is the only refracted ray. The plane b, which,
in this second case, answers to the plane a in the tirst case, is per-
pendicular to the plane ot'm, and parallel to the right line t'm.

If the incident ray be polarized in a direction intermediate between
the two transversal directions which give only a single refracted ray,
the incident vibration may be resolved into two vibrations ?>arallel to
those two transversals. The reflected vibrations arising from each
of the component incident vibrations are to be found by the fore-
going rules, and then to be compounded.

When the intersection of the planes a and b is perpendicular to
the direction of the reflected ray, this ray is polarized parallel to that
intersection, whatever be the plane of polarization of the incident
ray. The angle of incidence at which this takes place is the
polarizing angle.

When the refracted ray ot or ot' is a normal to the wave-surface,
the plane a or b is the plane of polarization of the ray. For example,
if ot be the ordinary ray in a uniaxal crystal, the plane a contains
the ray ot and the axis of the crystal.

The hypotheses from which Mr. MacCullagh has obtained the fore-
going laws, are these :

1. The density of the aether is the same in all media.

2. The vibrations are parallel to the plane of polarization.

3. The vis viva is preserved.

4. The vibrations are preserved : that is, the resultant of the in-
cident and reflected vibrations is the same as the resultant of the
refracted vibrations.

The author finds that his theory represents very accurately the ex-
periments of Sir David Brewster and M. Seebeck, on the light re-
flected in air from a surface of Iceland spar.

January 23. — Captain Portlock read a notice of the occur-
rence of Anatifa vitrea*, of Lamarck, in several localities on the
Irish coast. He commenced by enforcing the great importance of
recording as quickly as possible the first discovery in a new locality
of any species of the animal or vegetable kingdom, as tending to
perfect the Fauna or Flora of the district in which it is found; and
pointed out the value of such local Faunae and Florae in estimating
the relations and mutual dependencies of coexisting animals and
plants, and affording a basis of comparison by which future observers
may be enabled to test the probability of new organic beings occa-

• Lcpas fascicularis of Ellis, Montagu, and other authors; Lepas dilata
of Donovan.

136 Royal Irish Academy,

sionally appearing on the surface of the present earth, in the same
manner as they appear to have occurred at very distinct epochs in
the more ancient world*.

Captain Portlock then cited the various authors who have men-
tioned this species of the pedunculated division of Lamarck's class
Cinhipeda, beginning with its first discoverer, Ellis, who figured and
briefly described it in his Natural History of Zoophytes, published in
178$. It is there stated to have been obtained in St. George's Chan-
nel. It was afterwards found on the western coast of England by Mr.
Brier and Mr. Montagu, but is still considered there (as stated by
Turton in his Conchological Dictionary) very rare. The Rev. Dr.
Fleming communicated to the Wernerian Society, between 181 1 and
J 8 14, his discovery of the species in considerable abundance on the
coast of the Zetland Islands. Lamarck formed his species vitrea
from a specimen obtained on the shore of Noirmantier, an island off
the coast of Poitou, apparently the first noticed in France. He had,
however, seen a specimen of the Lepas fascicularis, sent him by Mr.
[afterwards Dr.] Leach, and states his opinion that it is only a variety
of vitrea. A cluster of this species of Cirrhipedae having been sent
to Captain Portlock by one of the Ordnance Survey Collectors, from
the ncrth coast of Antrim in the autumn of the last year, he was in-
duced to make further inquiry as to its previously known existence in
Ireland, and having mentioned the circumstance to Mr. R. Ball, was
informed by him of four cases of its occurrence which he had recorded,
viz. on the coast of Youghal in 1819 ; coast of Clare, 1823 j coast
of Clare, 1828 ; coast of Antrim, 1834. These localities, therefore,
taken with his own, constitute a very wide range, and show that this
species, still considered as very rare on the coast of England, and
apparently equally so in France, has been traced round the western
shore from the north to the south of Ireland. Specimens of Anatifa
l&vis, Lamarck, (Lepas Anatifera, Linn.,) accompanied those of
vitrea. This is a common species all round the Irish coast. Captain
Portlock mentioned that Mr. Ball had either in possession, or a record
of, the following species of Cirrhipedge, as Irish :

Anatifa sulcata, (Lepas sulcata, Mont.), Youghal j found also by
Mr. O'Kelly, near Kenmare.

Anatifa striata, Lamarck, (Lepas Anserifera, Linn.,) Dublin Bay.

Pollicipes scolpellum, Lamarck, (Lepas scalpellum, Mont.,) found
by Mr. W. H. Harvey in Dublin Bay.

Cineras vittata, Leach, Lamarck, (Lepas membranacea, Turtonj)
attached to a plank cast on shore near Malahide.

Otion Cuvieri, Leach, Lamarck, (Lepas aurita, Linn.,) attached
with a Cineras to a Balanus. The whole constituting a very large
proportion of the pedunculated Cirrhipedes at present known in.
Great Britain.

Professor Lloyd exhibited to the Academy some modifications which
have been recently made in the construction of the Magneto-electric
machine.

• We are glad to see the consideration of this almost neglected subject
thus brought forward in a definite manner. Its relations to the philosophy
of both zoology and geology appear to us to be very important. — Edit.

[ 137 ]
XVI. Intelligence and Miscellaneous Articles.

REMARKS ON THE COMMENCEMENT OF SIR E. FF. BROMHEAD's
TAPER ON BOTANICAL CLASSIFICATION.

The subjoined remarks were intended to be appended as a note to this
paper, but were omitted for want of room, as stated in p. 51.

THE introductory passages of Sir E. Ffrench Bromhead's inter-
esting paper have vividly reminded us of the principles on
which the natural arrangement of organized beings should be in-
vestigated, as laid down in the Hone Entomologicce. The principle
of the " first attempt to arrange natural families," that of assemblage,
is one of those on which Mr. Macleay has most strongly insisted.
The remark on the representation of the progress of development
by a spiral, perfectly agrees with the result of investigating the affi-
nities of animals, already compared by the Rev. Mr. Kirby (Intro-
duction to Entomology, vol. iv. chap, xlvii. p. 407.) to *' a convol-
ving series." We may add, however, that the relation between the
opposite points of contiguous whorls of the spiral, " which appear
to be the nearest, though distant by a whole round," is of a different
nature from that which unites into a series the groups forming
each whorl. The former is the relation of analogy : the latter that
of affinity. Were Sir E. Ff. Bromhead to subject the principles
hitherto followed in investigating the classification of plants, and
those advocated by Mr. Macleay, to the reciprocally severe test of
applying the latter, directly, to botanical arrangement, and com-
paring the results, we are convinced that new light would be thrown
on the subject of classification in general. We understand that
Mr. Macleay himself, while surrounded with the varied forms of tro-
pical vegetation, has pursued this line of research, and found that
the principles which he has already demonstrated to pervade the
animal world are equally apparent as regulating the vegetable king-
dom. Nothing could aid the progress of the science of natural
arrangement, generally, more than the publication of the results
which Mr. Macleay has obtained. May we hope that he will not
long delay to present them to the world?
June 21, 1837. E. W. B.

ON THE COLOURING MATTER OF THE ANCIENT RUBY GLASS.
BY J. T. COOPER, ESQ.

To Richard Taylor ', Esq.
Dear Sir,

Since the publication of my paper in the Annals of Philosophy,
to which Mr. Essex has referred in your No. for June, as relating
to the composition of the ancient ruby glass, I have obtained a
variety of specimens from various places, which I have also submit-
ted to analysis for the purpose of determining whether they all agree
in containing silver as a necessary constituent, which I find not to
be the case ; but in most instances, and in those which possess

Third Series. Vol. 11. No. 65. Supplement. July 1837. T

1 38 Intelligence and Miscellaneous Articles.

the brightest tints, I have invariably found traces of that metal,
but in variable quantities.

Another circumstance which had escaped my observation at the
time I prepared the communication alluded to, and which accounts
for the fact that Mr. Essex states, namely, that the old ruby glass
may be painted on and passed through the fire any number of times
without altering its colour, arises from the colouring material, viz.
the oxide of copper, being inclosed between two layers of the glass,
constituting a film of about the two hundredth part of an inch in
thickness ; and in one instance, that of a piece 1 brought from Stras-
burg cathedral which is of a very deep tint, there are two such films
inclosed between three layers of the ordinary glass. I may also
remark that oxide of iron is invariably to be found ; but this, as far
as I have been able to determine, does not form any portion of the
colouring ingredient, but exists in the common glass, from the im-
pure materials of which it has been made.

I remain, dear Sir, yours very truly,

82, BlackfriarsRoad, June 15, 1837. XT. Cooper.

SIR ISAAC NEWTON'S MANUSCRIPTS.

We extract the following statements from the Morning Chronicle, to the

Editor of which they are addressed.

Sir — A paragraph appeared in yesterday's Chronicle stating that
" the Council of the Royal Society have lately purchased from the de-
scendants of Sir Isaac Newton all the letters, manuscripts, and vari-
ous unpublished documents left behind him at his death by that illus-
trious philosopher,* * and that " these valuable papers are placed in the
hands of a very eminent person, and sueh-ef them as are important
to science will shortly be given to the public." As the writer of this
paragraph appears to have been completely misinformed, and the sub-
ject is one in which the scientific world feels a strong interest, you will
probably allow room for the following brief statement of the facts : —

On the death of Sir Isaac Newton all his manuscripts and papers
fell into the possession of Mr. Conduit, whose only child, a daughter,
married into the Lymington family ; from her they have descended
by inheritance to the present Earl of Portsmouth, and are now in the
custody of His Lordship's family. It may therefore be presumed that
no intention of selling them has ever been entertained ; at all events,
no purchase of them has been made by the Council of the Royal So-
ciety, nor has that learned body acquired possession of them, or con-
trol over them, in any way whatever.

The circumstance of the Newton MSS. having been locked up from
the public inspection has, however, long been matter of regret to
scientific men; and the recent publication of Flamsteed's correspond-
ence, in which the conduct of Newton, as President of the Royal
Society, is so bitterly censured, has given a new and extraordinary
interest to all matters connected with his personal history. It is
reasonable to expect that a complete vindication of Newton's charac-
ter from the aspersions cast on it by the irascible and prejudiced
astronomer will be found among those papers. Mr. Baily, indeed, in
his Life of Flamsteed, says he can state most decidedly that they

Intelligence and Miscellaneous Articles. 139

contain many documents and much information connected with
Newton's life and pursuits that are now highly interesting, and not
generally known. The announcement, therefore, that the MSS. are
now " placed in the hands of an eminent person," with a view to
their publication, will be hailed with satisfaction by every friend of
science and admirer of Newton, provided they are to be published in
an authentic and unmutilated form. But as considerable feeling has
already been displayed in connection with this subject, it would be
far more satisfactory if the selection were made by a committee of
competent persons, acting under the authority of a scientific body,
and not left to the discretion of any individual, however eminent,
especially as the original documents are not accessible to those
who desire to investigate for themselves. Government, it has
been stated, some time ago, expressed a willingness to print
them at the public expense. It is greatly to be regretted that this
proposal was not agreed to. Controverted points in the history of
science cannot be set at rest, nor will the reputation of Newton be
consulted, by the publication of extracts, however copious and impar-
tially made. The MSS. form a voluminous mass j it is not, therefore,
to be expected that they will be printed entire -} but, on the other
hand, it will be a just subject of national reproach if the corre-
spondence of the most illustrious individual whoever adornedour coun-
try is garbled for the purposes of a bookmaking speculation. A. B.
—Morn. Chron. June 21, 1837.

Sir Isaac Newton s Manuscripts. — [From a Correspondent.] An er-
roneous statement having found its way into the newspapers, respect-
ing the purchase of Sir Isaac Newton's MSS. by the Royal Society,
we are authorized to state that it has no foundation whatever. In conse-
quence of Sir David Brewster being at present engaged in a large work
on the life, writings, and discoveries of Sir Isaac Newton, he was
kindly permitted by the trustees of the Earl of Portsmouth to examine
the valuable collection of MSS. at Hursbourne Park. With the as-
sistance of H. A. W. Fellowes, Esq., the accomplished nephew of
Lord Portsmouth, many interesting and important letters and papers
were discovered, which not only throw much new light on the early
life and studies of our immortal countryman, but tend to refute the
groundless rumours respecting a temporary derangement of his mind
in 1 692, and to exalt, in the highest degree, his moral and intellectual
character. — lb. June 27.

ANALYSIS OF CITRIC .ETHER. BY M. MALAGUTI.

The process recommended to obtain this aether is the following :
take 90 parts of crystallized citric acid, 110 of alcohol of sp. gr.
0*814, and 50 of concentrated sulphuric acid. Put the citric acid,
powdered, and alcohol into a tubulated retort, then add the sulphu-
ric acid in small portions. Heat the mixture gradually to ebullition,
and stop the process, when a very sensible disengagement of sul-
phuric aether occurs, which happens when about one third of the
volume of the alcohol employed is distilled ; the residue is to b e
removed from the retort, and twice its volume of distilled water is
to be added to it ; an oily matter almost instantaneously collects at

T2

140 Intelligence and Miscellaneous Articles.

the bottom of the vessel, which is citric aether ; it must be repeat-
edly washed with cold water, and afterwards with a dilute alkaline
solution. When the liquid which floats upon the aether leaves no
residue on drying, the washing is to be discontinued, and the aether
is to be dissolved in alcohol ; this solution, which has considerable
colour, is to be digested with pure animal charcoal : it is then to be
filtered, and the desiccation is to be finished in vacuo. If 8T6^oz.
avoirdupoise be employed, the experiment requires only about an
hour for its completion, and the product amounts to above 5^ oz-
Pure citric aether is liquid, transparent, of an oily consistence, and
a yellowish colour. Its smell somewhat resembles that of olive oil,
its taste is bitter and disagreeable, and its density 1*142 ; it is vo-
latile, but the temperature at which it volatilizes is so near that at
which it decomposes, that it cannot be distilled without the decom-
position of a large portion of it. If it be heated in an open vessel,
it emits a very dense vapour, which inflames on the approach of
flame, and a coaly residue is left. In close vessels it begins to lose
its limpidity at about 248° Fahrenheit, becomes reddish at 518°,
and begins to boil and to decompose at about 542°; an oily matter
being disengaged, afterwards dilute alcohol, lastly carburetted gases
and citric aether [acid ?] ; the residue is charcoal.

Citric aether is perfectly neutral, leaving no residue after combus-
tion ; it is soluble in aether, in weak alcohol, and even slightly so
in water. An aqueous solution of citric aether becomes acid after
some time, and much more quickly so if heated. If citric aether be
boiled with a solution of potash or soda, alcohol is obtained, with
citrate of the alkali. Solution of ammonia has no immediate action,
nor has the dry gas. Neither barytes nor strontian water render
either citric aether, or a fresh solution in water, turbid. Nitric
acid dissolves it cold, and if the solution be poured into water, the
aether does not separate. When the nitric solution is gently heated,
a brisk action occurs, which goes on spontaneously ; there is a dis-
engagement of red vapours, and the residue has a smell resembling
that of hyponitrous acid. If considerable quantities be acted upon,
and the ebullition be long continued, oxalic acid is found in the re-
sidue; this residue, which is slightly yellow, becomes of a deep red
when saturated with ammonia.

Concentrated sulphuric acid immediately imparts colour to citric
aether; it dissolves it cold, but quits it on the addition of water, and
the aether is unchanged. The sulphuric solution when heated to
about 158°, begins to exhibit appearances of a reaction, which be-
comes extremely strong as the temperature increases ; there is a
disengagement of alcohol and sulphuric aether, and the residue is
red, transparent, very thick, and soluble in water.

Hydrochloric acid dissolves citric aether cold, as the other two
acids do, and quits it on the addition of water. The hydrochloric
solution does not exhibit any appearance of reaction; the liquid
boils, hydrochloric aether is disengaged ; a little alcohol, and no citric
Kther, remain in the residue.

Potassium put in contact with citric aether occasions disengage-
ment of a gas • but the .action stops as soon as the surface of the

Intelligence and Miscellaneous Articles. 141

metal is oxidized, which very soon occurs ; whether this action is
occasioned by the decomposition of the aether, or of a little water
which it may contain, was not determined.
By analysis this aether yielded, nearly,

Hydrogen 7*29

Carbon 51-00

Oxygen 41*71

100-
If constituted of an equivalent of citric acid 58 and an equivalent
of aether 37, it would consist of

Seven equivalents of Hydrogen . . 7 or 7*37
Eight equivalents of Carbon .... 48 „ 50*52
Five equivalents of Oxygen .... 40 „ 42*11

95 100*
This agrees very nearly with Malaguti's analysis, and perfectly
with his symbolic representation of its constitution, the weights re-
presenting the equivalents varying slightly.

Ann. de Ch. et de Phys., October 1836.

ON THE COMBINATIONS OF AMMONIA WITH ANHYDROUS SALTS.

M. Rose has examined a considerable number of the compounds
which dry ammonia forms with anhydrous salts, volatile metallic
chlorides, and oxacids, with the view of ascertaining the general
laws to which these combinations are subject.

Their preparation is very simple, but requires time ; the ammonia
should be passed into a vessel containing caustic potash or lime,
and then through a tube filled with caustic potash in small lumps,
before it comes in contact with the salt, which is weighed before the
operation, the current of ammoniacalgas being continued as long as
the salt increases in weight. The combination is usually effected
in the cold, and if the substance becomes heated the current of
gas must be decreased. The absorption is at first very rapid, but
becomes slower by degrees, so much so, that even with those sub-
stances which absorb ammonia with avidity, the operation often re-
quires (wo days. We shall describe the general properties without
going into the details of all the compounds examined by M.Rose.

The sulphates of manganese, zinc, copper, nickel, cobalt, cad-
mium and silver, and the nitrate of the last metal, absorb ammonia;
on the contrary, the sulphates of magnesia, nitrates of soda and
barytes, phosphate of copper and bichromate of potash do not unite
with this alkali. Among the combinations of chlorine with the me-
tals whose oxides are basic, there are many which act with am-
monia in a precisely similar manner to the oxacid salts ; such are
the chlorides of calcium, strontium, copper, nickel, cobalt, lead,
silver, the proto- and perchloride of mercury, protochloride of
antimony, the perbromide, periodide, and cyanide of mercury.
The cyanuret of iron and potassium does not absorb ammonia,

142 Intelligence and Miscellaneous Articles.

nor is it when cold at all acted upon by it. From his numerous
researches Mr. Rose draws the following conclusions : many ox-
ides, and many chlorides whose oxides form bases, can combine with
ammonia, but there are some which do not possess this property
although they resemble the former class in many points. When an
anhydrous salt unites with ammonia it always forms a determinate
compound. Salts which agree in many of their properties absorb
ammonia often in the same, very often also in different proportions,
so that the combinations of anhydrous salts and ammonia do not come
under any law so constant as to admit of an cl priori calculation of
their relative proportions in a compound. Ammonia acts with an-
hydrous salts and the metallic chlorides analogous to them, as an
extremely feeble base, abandoning almost the whole of them, mostly
or altogether, when they are exposed to the air, or a very gentle
heat : the only exceptions are combinations with perchloride and
perbromide of mercury which do not give off ammonia when heated,
which property necessarily places them amongst a particular class
of ammoniacal compounds.

The combinations of ammonia with the oxacid anhydrous salts
and the analogous metallic chlorides present a striking resemblance
to the compounds which the same salts form with water. Thus water
does not combine with all salts, and even amongst those whose pro-
perties are extremely analogous some will be found containing and
others not containing water. Thus chloride of calcium absorbs a
large quantity of ammonia whilst chloride of barium combines with
none ; sulphate of lime also unites with water of crystallization,
whilst sulphate of bary tes does not contain any. Besides, the water
of crystallization exists in a determinate proportion in all its com-
binations with salts; yet salts possessing very similar properties often
combine with very different proportions of water. Finally, water in its
combination with salts maybe considered as a base, although a very
weak one, and which can be usually expelled by a moderate heat.*—
Jour, de Phar., Jan. 1837.

ON THE OXALHYDRJC ACID OF M. GUFJilN.

M. Erdmann of Leipsick considers that the composition of the
acid obtained by the treatment of sugar (acide oxalhydrique of
M. Guerin, artificial malic acid,) is the same as tartaric acid; for if
a solution of this acid is allowed to stand for some time it is con-
verted into common tartaric acid, the oxalhydrates are converted
into common tartrates, and the crystallized oxalhydrate of am-
monia described by M. Guerin is a tartrate of that base. A further
examination has proved that this acid is identical with the isomeric
tartaric acid of M. Braconnot obtained by the fusion of common
tartaric acid. M. Liebig has procured well-formed crystals of tar-
taric acid from an acid syrup remaining after the preparation of
oxalic acid from sugar and nitric acid which had been left to it-
self for a length of time. These researches will remove all the ano-
malies of the oxalhydrates ofM. Guerin. — VInstitut, April, 1837-

* See Professor Graham on this subject, Lond. and Edinb. Phil. Mag.,
vol. vi. p. 327, et seq., vol. vii. p. 400.

Intelligence and Miscellaneous Articles. 143

NATIVE IODIDE OF MERCURY.

M. Del Rio having noticed on some specimens of seleniuret of
mercury in the collection of L'Ecole des Mines of Mexico, some
particles of a reddish brown colour, submitted them to the blow-
pipe, when they afforded evident indications of iodide of mercury,
agreeing in its characters with the artificial iodide. — Journ. de Chim.
Med. Feb. 1837.

CARBOMETHYLATE OF BARYTES.
This salt occurs in white shining plates, is soluble in water, and
is not decomposed by exposure to the atmosphere nor in vacuo : its
composition according to MM. Dumas and Peligot the discoverers
is indicated by the formula

BaO + 00* + C*H9+ C*0* + OH.

Dissolved in water it spontaneously decomposes even at common
temperatures, into carbonate of barytes, carbonic acid, and pyroxylic
spirit (bihydrate of methylene or carbo-hydrogen). This decom-
position is accelerated by heat, and is complete before the aqueous
solution is raised to ebullition. — Ulnstitut, 20th March.

ANALYSIS OF GADOLIN1TE. BY MR. A. CONNELL.

Yttria 36-54?

Glucina .5*90

Protoxide of cerium 14*31

Protoxide of iron 14*14

Silica 27-10

Lime *45

98*44
In the statement of this analysis in the New Edition of Phillips's
Mineralogy, the silica has been, by a typographical error, omitted.

METEOROLOGICAL OBSERVATIONS FOR MAY 1837.

Chiswick. — May I, 2. Fine. 3. Hazy. 4 — 7. Very fine. 8. Rain.
9. Cloudy; fine, clear and cold. 10. Cloudy and cold. 11. Fine.

12. Drizzly. 13. Fine: rain. 14. Hazy : cloudy and fine. 15. Cloudy,
and cold : fine. 16 — 18. Fine. 19. Cold rain. 20, 21. Slight rain.
22. Cloudy and cold : hail showers : stormy with rain. 23. Cloudy.

24. Slight haze : frosty at night. 25 — 29. Very fine. 30. Fine : rain

at night. 31. Slight rain.

Erratum. — In the last Number, the minimum average of the barome-
trical pressure should be 29*777 instead of 29-868, which it will be ob-
served is the average of the max. observation!.

Boston.— May 1. Cloudy. 2— 5. Fine. 6. Cloudy. 7. Fine.

8. Cloudy : rain early a.m. : rain p.m. 9. Cloudy. 10. Fine : rain and
hail a.m. and p.m. 11. Fine. 12. Cloudy. 13, 14. Fine. 15. Fine,
rain p.m. 16. Cloudy. 17, 18. Fine. 19, 20. Cloudy: rain early a.m. :
21. Cloudy. 22. Fine : rain early a.m. 23. Fine. 24. Cloudy.

25—28. Fine. 29. Cloudy. 30. Cloudy: rain and hail with thunder
and lightning p.m. 31. Fine.

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THE

LONDON and EDINBURGH

PHILOSOPHICAL MAGAZINE

AND

JOURNAL OF SCIENCE.

[THIRD SERIES.]

AUGUST 1837.

XVII. On the Use of Sulphate of Copper for exciting Voltaic
Electricity ) and on the Employment of Iron in the Construe-
Hon of Batteries. By Andrew Fyfe, M.D., F.R.S.E.,
Lecturer on Chemistry, Edinburgh*

r| ^HE action of metals with metallic salts has been long
•*• known, but it is only lately that the latter have been used
in electric arrangements, and chiefly for electro-magnetic pur-
poses. Aware that sulphate of copper was easily decomposed
by zinc, I was induced some time ago to try it, when used as
the exciting fluid in the galvanic battery, and found that in
its action it is far superior to the acids in common use. It is
however unnecessary for me to relate the experiments that
were performed, as I find that it has been made the subject
of investigation by others, particularly by Mr. Faraday, the
results of whose labours are already, so far, before the public.
Since first using the sulphate of copper, I have been Jed to
inquire not only as to its powers compared with other fluids,
but also whether other combinations of that metal would not
act equally well, or perhaps more powerfully, and it is to the
use of these, in comparison with acids of different strengths,
not only in batteries as usually constructed, but likewise in
other modifications of them, that I wish to advert.

In the tenth series of his experimental researches, Mr. Fa-
raday has shown, that in voltaic arrangements the electroly-
zation depends, along with other causes, on the kind of trough

* Communicated by the Author.
Third Series. Vol. 11. No. 66. Aug. 1837. U

146 Dr. Fyfe on the Use of Sulphate of Copper

employed. In a voltaic circuit the forces which make the in-
strument active are of two kinds, the one local, the other that
which is transmitted along the object by which the communi-
cation is established. Of course it is of the utmost conse-
quence in all voltaic arrangements, to have as much as possible
of the latter made to circulate, because it is by means of it
that electrolytic action is effected. By using the trough re-
commended in the paper alluded to, Mr. Faraday found, that
for the same destruction of zinc, the electrolytic action, in
other words the quantity of electricity transmitted through the
electrolyte, was greater than when a trough of ordinary con-
struction was used. In the trough mentioned, which by
Faraday is considered superior to the best previously in use,
viz. that with double coppers, in which the cells are insulated,
there was, even when acting under favourable circumstances,
a considerable waste of electricity. In a perfect trough this
would not be the case, but as in all arrangements now in use
it has been found to be so, owing to the interfering powers,
which prevent the transference of electricity from one end to
the other, it is desirable to discover means by which it may
be prevented, so that if possible there should be no waste
of the electrolytic agent, provided at the same time we can
do so by means equally ceconomical with those commonly re-
sorted to; and I trust that the experiments now to be stated
will show that this is, to a certain extent, within our reach.

The trough generally employed in the following experiments
consisted of thirty copper and zinc plates, on the principle of
the couronne des tasses; the copper three inches square, the zinc
three inches long and one and a half wide. It was capable
of holding sixty ounces of fluid. The measure of the quantity
of electricity conveyed through the electrolyte was of course
that pointed out by Faraday ; using in all the experiments
solution of sulphate of soda, always of the same strength, in
the volta-electrometer, and electrodes of the same size. The
experiments were occasionally varied by sometimes collecting
both gases, and sometimes only one : 25 degrees of the volta-
electrometer were equal to one cubic inch.

Oil of Vitriol. — When diluted oil of vitriol is used, the loss
of electricity is considerable, and depends much on its state
of dilution. 163*3 grains by weight, when mixed with sixty
ounces of water, discharged 14 measures of hydrogen in the
volta-electrometer. 490 grs., that is, three times as much,
diluted with the same quantity of water as above, discharged
very nearly three times as much gas; but when 1470 grs.
were used, I did not find that the amount of decomposition

for exciting Voltaic Electricity, 147

was increased; in fact, ihey yielded only 40 measures of gas,
or 1*6 cubic inch, which was the quantity discharged by 490
grains.

When 490 grs. of the acid are used in the trough with
thirty plates, these by their action should in each cell excite a
decomposition, which should evolve 15*75 cubic inches of hy-
drogen, and of course the same quantity in the fluid electro-
lyzed; whereas only 1*6 cubic inch was evolved. When three
times as much acid was used, the quantity of gas disengaged
was the same ; so that the loss of electricity was in that case
very great, the gas evolved being to that which should have
been evolved, provided the whole of the electricity were trans-
mitted, as 1*6 to 47*25 or as 1 to 29*5 : of course, these and the
following experiments are not given with the view of showing
the actual amount of decomposition that may be effected by
sulphuric acid, because much depends on the kind of trough,
and other circumstances. But as the circumstances under
which they were conducted were generally the same, they may
be considered as pointing out under similar circumstances the
comparative amount of decomposition.

Sulphate of Copper, — In the experiments with oil of vitriol
490 grs. were used as being the equivalent compared to hy-
drogen as 10. As blue vitriol is abisulphate and its equiva-
lent number 2500, it was necessary to employ 1250, or only
half of that number of it in trying its electrolytic power com-
pared to that of oil of vitriol under similar circumstances ; but
other quantities were also used, so as to ascertain the power
of solutions of different strengths. 1250 of the salt dissolved
in sixty ounces of water yielded 180 measures of hydrogen.
Now the gas given off by using 490 of oil of vitriol, and of
course 400 of sulphuric acid, was only 40 ; so that a quantity
of sulphate of copper, which contains the same proportion of
acid, and of course causing the same destruction of the plates
of the trough, yielded 4*5 times as much. When a weaker
solution was used, a proportionally greater quantity of gas
was set free. 416*6 grs. or £ yielded 82, which multiplied by
3 as 246, that is, rather more than six times the quantity given
off by a similar proportion of oil of vitriol. 246 measures of
the volta-electrometer are equal to 9*6 cubic inches, which de-
ducted from 15*75 leaves 6*15, so that the loss amounted to
39 per cent. When blue vitriol is employed the action is at
first by no means energetic, but it gradually becomes more
and more so for about an hour or so, after which it becomes
weaker; but it continues for a much longer time than when
oil of vitriol is used, the action of which is in general over
in less than an hour, whereas that of the other continues for

U2

148 Dr. Fyfe on the Use of Sulphate of Copper

eight or ten hours, indeed sometimes much longer, though
of course very feeble. I have occasionally observed the trough
in action at the expiration of thirty-six hours.

Nitrate of Copper. — The electrolytic action of nitrous acid,
as is well known, being more powerful than that of sulphuric
acid, naturally led me to try the effect of nitrate or rather bi-
nitrate of copper in the cells of the trough. Using half of its
equivalent, I found that the quantity of gas in the volta-
electrometer, was much greater than when sulphate was em-
ployed, showing that by means of it there was a greater trans-
mission of electricity. But as the use of the nitrate is pre-
cluded, owing to its expense, I was induced to try what effect
the addition of other salts, such as a nitrate, would have, either
by causing the decomposition of the sulphate, and its conver-
sion into nitrate, or perhaps by increasing the conducting
power, and consequently admitting of the more ready trans-
mission of the electrolytic agent.

Sulphate of Copper and Nitrate of Potass, — Nitre was the
salt to which I first had recourse, two equivalents of which
are necessary for the decomposition of one of blue vitriol.
In using this mixture I found that the power was increased,
but the results were not always the same; in some they were
as 40 to 57, in others as 40 to 53. Using 1250 of blue vitriol
and 1040 of nitre, dissolved in sixty ounces of water, the gas
given off amounted on an average to 330, or 13*2 cubic inches.
The quantity that ought to be given off, supposing the whole
of the electricity transmitted, is 15*75, so that there was in
this case a loss of about 16 per cent., whereas when blue vi-
triol alone was used, under similar circumstances, the loss
amounted to 39 per cent. With oil of vitriol the loss was 90
per cent.

Sulphate of Copper and Sea Salt, — Having found the in-
crease in electrolytic action of the sulphate by admixture of
nitre I was next induced to try it with sea salt, using them in
the proportion of 1250 to 600. When these quantities were
employed dissolved in sixty ounces of water, the gas collected
in the volta-electrometer very nearly amounted to that given
off by the mixture of sulphate and nitre. It was generally
about 310, compared to the other as 330; so that it yielded
12*4 cub. inch. The deficiency therefore was 3*35 or 21 per
cent.

Though by the use of sulphate of copper, particularly when
mixed with other salts, there is little loss of electricity, it is
of importance to ascertain their expense, compared with that
of oil of vitriol, as indicated by the above experiments. The
commercial price of blue vitriol is to that of oil of vitriol as

Jbr exciting Voltaic Electricity, 149

4 to 1, and their equivalents nearly as 3 to 1, taking only
half of the atomic number of the former, because blue vitriol
is a bisulphate; so that for equivalents of sulphuric acid the
price is nearly as 12 to 1, but the former gives off' six times as
much gas as the latter, so that for equal electrolyzing power
the price would be nearly as 2 to 1 ; but then, to get the same
electrolyzing power requires six times the equivalent propor-
tion of acid, by which of course six times as much zinc must
be destroyed, which will add materially to the expense; in
other words, comparatively diminish that incurred by the use
of the sulphate of copper. When nitre is mixed with the sul-
phate the electrolytic action is as 8 to 1, so that the slight
additional expense of the nitre, without adding to the expen-
diture of zinc, is more than counterbalanced by the increase
of power. Though sea salt does not increase the electrolytic
action of the sulphate so much as nitre does, yet considering its
cheapness compared with it, it is the most ceconomical of the
substances tried. Thus 490 of oil of vitriol yielded 40 of gas,
and 1250 of sulphate of copper +600 sea salt gave 310, con-
sequently 490 with the requisite proportion of salt would
yield 120, or three times as much as the oil of vitriol would
do ; so that the expense of the fluids would be about 4 to 3.
But as eight equivalents of acid are required to yield the 310
of gas, and consequently eight equivalents of zinc consumed,
Ul other words, as only Jth of the quantity of zinc is de-
stroyed, for getting the same electrolytic action when the sa-
line solution is used, though the price of the fluids is as 4 to 3,
the expense would in all, even with the addition of the salt, be
only about half of that incurred by using the oil of vitriol.

The above remarks regarding the comparative expense of
the materials mentioned, it must be borne in mind, apply to
the electrolytic power when the troughs which are in common
use are employed. It is different when the trough recom-
mended by Faraday (Phil. Magazine, February 1836, Third
Series, vol. viii., p. 114,) is used. According to him, when
acting with nitrosulphuric acid it decomposed one equivalent
of water, at the expense of 2*21 equivalents of zinc, in each
plate, and of course of a corresponding quantity of acid ;
whereas were the whole of the electricity conveyed through
the electrolyte, 2*21 of water ought to have been decom-
posed ; so that there was a loss of about 55 per cent, of the
electrolytic agent. It has been already mentioned that with
sulphate of copper and nitre, while the quantity of water which
should have been decomposed would have yielded 15*75 cubic
inches of hydrogen, there were given off" only 13*2, and with
the mixture of sulphate and sea salt, only 1 2*6 cubic inches,

150 Dr. Fyfe on the Employment of Iron

making the loss in the former amount to about 16, and in the
latter to about 20 per cent.

But in this case, where nitric acid was added to the sul-
phuric, with the view of increasing the power, the expense
was considerably increased. When sulphuric acid alone was
used, there was much less electrolyzation indicated by the
volta-electrometer. For each equivalent of water decomposed,
4 66 of zinc in each plate, with of course a corresponding
quantity of acid, were consumed ; so that the loss of electro-
lytic power amounted to about 78 per cent. The loss was
therefore less ; in other words the electrolyzation was greater.
But this, though it alters the comparative expense, yet it does
so in a small degree ; because, if the electrolytic action in this
trough is greater with sulphuric acid, it will be greater also
with the metallic solutions. But even allowing that it is so
to a trifling extent, it has been shown that the comparative
powers of oil of vitriol and of the mixed salts are as 1 to 8,
and their expense as 2 to 1 ; so that if we suppose the electro-
lytic power with oil of vitriol in the experiments I have re-
corded as amounting to about 10 per cent., and that in Fara-
day's trough, with the same acid, as about 22 per cent., or
rather more than double, this would reduce the power of the
same trough with the mixed salts, compared to its power with
oil of vitriol, to about as 4 to 1, which would make the ex-
pense for the same amount of electrolyzation very nearly the
same in both cases. Viewing it in this light, still there would
be a saving, because the same electrolytic action would be ob-
tained, with less destruction of the trough, and consequently
the trouble and expense would thus be diminished.

The peculiar condition into which iron is brought by the
action of nitric acid, as discovered lately by Schcenbein, and
proved also by Faraday and others*, seemed to exclude the
prospect of its being used in the construction of voltaic troughs;
but considering the ease with which it is acted on by sulphate
of copper, I was induced to try it, in the hopes that the state
of inaction does not depend on the want of power in the iron
to convey the electric agent, but on some other cause, brought
into play by the action of the acid. I accordingly had a
trough constructed of copper and sheet iron, the plates being
of the same number and size as those in the zinc battery.
When diluted acid was poured into it, a smart electrolytic
action took place, accompanied by the discharge of gas in
the volta-electrometer; but in the course of a short time the
action became feeble, and though it went on for some time,

* See various papers in our last three volumes.— Edit.

in the Constmction of Voltaic Batteries. 151

yet it was very faint. The result was different when sulphate
of copper was used. The electrolyzation commenced almost
the instant that the trough was filled, and continued in the
same way as when zinc was employed ; indeed I could observe
very little difference as to energy of action, and to the time
that it continued, with this exception, that in general there
was rather less gas evolved in the volta-electrometer. That
evolved by the action of 1250 of the sulphate in the zinc
trough being 180, that afforded by the same quantity in the
iron trough was 173, or about yVth part less. When the sul-
phate was mixed with nitre and with sea salt, there was an
increase in power, similar to that when using them in the zinc
trough. When therefore blue vitriol is to be used in voltaic
arrangements, iron may be employed instead of zinc, with very
nearly the same electrolytic power. It has been already men-
tioned that when the blue vitriol is mixed with nitre, but more
particularly with sea salt, the expense is only about one half
of that incurred by the use of oil of vitriol. If iron be em-
ployed in the construction of the trough, the expense must of
course be still further reduced, sheet iron being only about
half the price of sheet zinc. Though in many cases it may
be thought advisable to use sheet iron, there is no necessity
for always having recourse to it. I have found that cast iron
answers nearly as well ; and when the troughs are to be long
and much in action, it may perhaps be more ceconomical to
use it, as there is always expense incurred by the repeated
soldering of new iron plates to the copper ones ; besides cast-
iron is cheaper than the other.

Before using the trough when constructed of iron, it is al-
ways necessary to wash the iron plates with diluted sulphuric
acid, which may be done before they are soldered to the cop-
per, or after it, by placing them in the trough filled with the
acid, and leaving them there for a few minutes.

Considering the cheapness of the materials used and the
comparatively little waste of electrolytic power, I conceive that
the trough as thus recommended may be employed advan-
tageously for many purposes of decomposition. Supposing
the iron trough to be used with sulphate of copper, metallic
copper and green vitriol are the products in the trough,
both of which may be turned to account; so that if by the
electrolytic action of a powerful battery, a valuable ingredient
could be obtained from the electrolyte, the decomposition
might in this way be advantageously accomplished.

There is one advantage attending the use of metallic solu-
tions. The adhesion of the precipitated copper does not seem
to impede much the action in the trough, and consequently

152 Mr. L. Hunton on the definite Combinations

to retard the progress of the electrolytic agent. A trough
which has been in action and consumed the whole of the fluid in
its cells, so as to have its plates covered with flocculent preci-
pitated copper, when emptied and again filled with the metallic
solution, soon again comes into action, and the electrolytic
action is the same, or nearly so, as at first. When the plates
are allowed to dry, and are in that state put into the trough
with the metallic solution, though there is at first no action,
yet it begins in the course of a short time, and goes on effect-
ing the electrolyzation of the electrolyte as before.

Though the trough acts in this way, it is better to wash off
the precipitated copper, because the whole surface of the metal
is thus exposed ; whereas when not washed off, unequal sur-
faces are exposed in the different plates, from part of the pre-
cipitate above being carried off when the trough is emptied,
and thus the action may not be the same in all the cells.
When iron is used, the plates after being washed ought to be
dried, before being set aside, because otherwise they become
covered with rust, which retards the action.

As it is of the utmost consequence to avoid as much as
possible expense in the fitting up of the trough, I have been
led to adopt a modification of that in common use, which is
easily renewed with little expense. Instead of using the plates
soldered together, the copper plates are fixed into the sides
of the trough, thus forming the partitions, on each of which
is suspended an iron or zinc plate, by bending the upper ex-
tremity, so as to form a sort of hook. This trough acts as
powerfully as the others in common use, and it has this ad-
vantage, that the iron or zinc plates are easily removed, and
cleaned, when required, and are, when destroyed, easily re-
placed by others. It is necessary to dry the plates after being
washed, to prevent oxidation at the upper extremity, by which
the metallic contact would be rendered imperfect.

XVIII. On the definite Combinations of Sugar with the Jlkalies
and Metallic Oxides. By Louis Hunton, Esq., F.G.S.*

\^7TIEN lime is added to a solution of sugar it is dissolved
" in considerable quantity. Dr. Ure in the last edition of
his Dictionary says : " Sugar dissolved in water at the tempe-
rature of 50° is capable of dissolving half its weight of lime."
This 1 believe will be found too large a proportion, for after
repeated trials I find its composition the same for every tem-
perature between 50° and 130° at which the solution is made

« Communicated by the Author.

of Sugar with the Alkalies and Metallic Oxides, 153

and filtered ; and from which solutions carefully evaporated
under 180° (the compound being insoluble at higher tempe-
ratures), and then dried at 212°, 100 grs. give from 22 \ to
23£ per cent, of lime. Now if, with Berzelius, we consider
sugar dried at 212° as CleH10O1Q + HO =171, from 23 per

cent, we shall have 51*07 as the number for lime, too small for
two proportions ; but should the lime be as a hydrate, instead
of 23 we shall have 30*4, leaving the sugar 69*6 per cent.; or
for 171, 56*7 as the number for lime, equal to two proportions,
A better way to obtain the composition, on account of the diffi-
culty of preventing the formation of a little carbonate, is to
add alcohol to the filtered solutions, and then wash the curdy
precipitate with proof spirit ; this precipitate when dried at
212° gave 22*65 per cent, of lime = 29*93 hydrate, which
gives 55*27 as the proportion to one of sugar; hence

Saccharate of lime (C12 H10 O10 + HO + 2CaO + 2HO)
= 24-5.

If a solution of the saccharate of lime be added to hydrated
deutoxide of copper, we obtain a bright blue solution, much
resembling the ammoniuret; this evaporated under 160° leaves
a crystalline substance permanent in the air, which dried at
212° has the following composition : 10 grains, after account-
ing for a little carbonic acid absorbed during evaporation,

gave Lime 1*63 = 2*154 hydrate.

Deutoxide 2*33 = 2*586 do.

4*74
leaving 5*26 for the sugar, but which to be in proportion to
the lime should be 4*98 ; the *28 may probably have arisen
from a little unexpelled water : thus we may consider the
above as

1 Sugar = 171 = 57*2

2 CaO + 2HO = 74 = 22*15
CuOHHO = 89 = 26*65

334 100*

The relations of this calcareo-saccharate to oxygen are
rather singular; if we heat a little of the solution to 160°, a
flaky blue precipitate is separated, that entirely redissolves
again on cooling, which could not be the case had any prot-
oxide been formed. This being apparently at variance with
some of the results obtained by M. Becquerel in his experi-
ments on the varieties of sugar (in which he shows that hydrated
oxide of copper agitated with sugar and an alkali is dissolved,
but precipitated again as protoxide when boiled,) I was in-

Third Series, Vol. 11. No. 66. ^.1837. X

154 Mr. L. Hun ton on the definite Combinations

duced to examine further, and found that though the solution
when heated in an open shallow vessel, as a watch-glass, may
be alternately raised to ebullition and cooled, for several times
in succession, without forming any permanently insoluble pre-
cipitate, yet if heated but once, or twice at the furthest, in a
deep narrow-mouthed vessel, as a test tube, a separation of
protoxide takes place. The presence of free or uncombined
sugar is also of much consequence, for if we add a little to
any of the saturated solution and then heat, insoluble prot-
oxide is formed even in a watch-glass ; on the contrary, a free
alkali appears to retard the deoxidation in the test tube, and
to prevent the formation of a little which takes place after
four or five heatings in a watch-glass, and resulting from the
formation of a little carbonate of lime, and consequent setting
free of sugar.

If instead of boiling, a few test tubes are filled with the so-
lution, a result variable with the difference of exposure and
presence of free sugar is obtained ; thus,

In open tubes. In closed tubes.

No. 1. Solution alone. No. 4. Solution alone.

— 2. Do. and free sugar. — 5. Do. and free sugar.

— 3. Do. and free potash. — 6. Do. and free potash.
In the open tubes, No. 1 did not form any protoxide until

it had stood a week, when a slight deposition, accompanied by
carbonate of lime, took place ; No. c2 formed protoxide after
twelve hours, and gradually increased it; whilst No. 3 did not
form any for a month, when a trace appeared, and at the same
time crystals of carbonate of lime. But in the closed tubes,
after twelve hours' standing, protoxide had formed in all; that
in Nos. 4 and 6 was slight, whilst that in No. 5 was consider-
able. Carbonate of lime did not appear until they had stood
a week.

In order to ascertain the exact action of sugar on the oxide
of copper, a portion of the hydrate having been agitated with
a syrup in the cold for three days without any effect was
brought to boil, and though none was dissolved, yet the hydrate
was prevented parting with its water and becoming brown as
in ordinary cases ; and continuing the boiling the peroxide
was slowly converted to the yellow one, the change being
complete after some hours ; and the sugar, though having
thus partially deoxidized the copper, appears in proximate
properties to have itself suffered no change. If prior to the
boiling the smallest quantity of potash or other alkali had
been added, a part of the hydrate would have been imme-
diately dissolved, acted on by the free sugar present, and pre-
cipitated as protoxide, the alkaline saccharate then renewing

of Sugar with the Alkalies and Metallic Oxides. 1 55

its action on the hydrate, which is no sooner dissolved than
deoxidized by excess of sugar, the whole being thus quickly
converted to the yellow oxide; and in this experiment copper
is always present in solution, proportionate to the quantity of
alkaline saccharate.

It is worthy of remark, that if the deutoxide has been pre-
viously deprived of its water and then heated with sugar, it
resists the action ; at least three hours' boiling did not affect
it: but saccharate of lime (or any other alkaline saccharate)
boiled with it is capable of dissolving and deoxidizing it,
though with more difficulty than the hydrate.

A somewhat similar deoxidizing action occurs when sugar
is boiled with acetate of copper, the whole of the metal being
gradually deposited of a fine orange-red colour, very much re-
sembling the outer coating of a bar of Japanese copper, and
with it may possibly be the metal in a lower state of oxidation
than any yet known : the acetic acid going off in vapour, leaves
the syrup when cold equally free from acid and oxide.

On substituting an oxide of iron for that of copper it is
equally well dissolved by the saccharate of lime, but in this
case it is the protoxide ; and owing to the metal being al-
ready at its minimum, the addition of free sugar causes when
boiled no further deoxidation ; but this solution is very liable
to decomposition either in closed or open vessels, carbonates
of lime and iron crystallizing from it. On evaporating and
drying at 212°, 10 grains gave

Lime = 1-8 = Hydrate 2*38

Protoxide of iron = 1-17 = Do 1*463

In this case 5 per cent, of carbonic acid had been absorbed
during evaporation, which deducted from 10 grs. leaves the
composition,

1 Sugar = 171 = 58*6

2 Ca O + 2 H O = 7(5 = 26'

lFeO+HO = 45 = 15-4

292 100- .

The iron in this calcareo-saccharate, though insensible to
ferrocyanates and alkalies, is precipitated by both succinate
and benzoate of ammonia.

On adding a precipitated protoxide of lead to the saccha-
rate of lime, a pale amber-coloured crystalline substance is pro-
duced on evaporation, 10 grains of which dried at 212°, give

Lime 1*5

Protoxide of lead 3*0

X2

1 56 J. C Marquart's Report of the Progress of Phytochemistry

hence the following composition :

1 Sugar = 171 = 46*72

2CaO + 2HO = 74 = 20*22

PIO+HO = 121 = 33*06

366 100.

Baryta and Strontia Saccharates.— By agitating a syrup
with either of the hydrates of these earths, and then with the
oxides of copper, iron, or lead, we obtain solutions which
behave very much the same as the calcareous saccharates.

Potassa and Soda Saccharates. — When either of the fixed
alkalies are united with sugar in their atomic proportions, we
obtain solutions which dissolve the hydrated oxides, but which
triple solutions continue soluble at 212°, though a further ad-
dition of free sugar causes a precipitation of protoxide when
the solution of copper is heated.

Loftus near Guisborough, May 21, 1837. Louis Hunton.

XIX. A Report of the Progress of Phytochemistry in the year
1835, in reference to the Physiology of Plants. By J. Cl.
Marquart.*

[Continued from vol. x. p. 252.]

T EXAMINED with M. F. Nees von Esenbeckf the bloom
of the fruit of Benincasa cerifera, which consisted mostly
of a whitish wax (66 per cent.), of resin (29 percent.), and of
extractive matter (5 per cent.). The first possessed the same
properties with regard to solvents as vegetable wax; but was
remarkable particularly on account of its high melting point,
viz. at 100—120° Reaum. We found as a discriminating
character for this wax, by which it may be distinguished from
the numerous resins of difficult solution, its reaction with sul-
phuric acid in the cold, as it is scarcely coloured by it, or not
at all if the wax is very pure. We examined in regard to
this the so-called Japanese wax of Rhus succedanea, the wax of
Corypha cerifera, and the wax from the seed-lac of Aleurites
lacctfera, which corresponded with the bloom of the Benincasa.
According to Boussingault^ the composition of the wax-like
envelope of Ceroxylon andicola, which entirely covers that
palm, often reaching to the height of fifty feet, is the same

* From Wiegmann's Archivfiir Naturgeschichte, vol. ii. part iv. p. 139
et seq. Translated by Mr. Fram is.
f Buchn. Repert.y vol. Ii. part 3.
J Annates de Chimic et de Physique , May 1835.

in the Year 1835, in reference to the Physiology of Plants, 157

as that of the bloom of the fruit of this Cucurbitaceous plant.
The wax of this envelope melts, however, at a much lower
temperature, even below 80° Reaum., is little coloured, resem-
bles bees' wax, and has the same elementary composition.

M. Mulder found in the husk or rind of coloured fruits, as
those of Pyrus Mains, Capsicum annuum, Sorbus aucuparia,
Cucurbita Lagenaria, invariably combined with the colouring
matter, a wax which was always found to be a pure cerin *.
By the experiment before mentioned, M. Du Menil obtained
from the bark of Finns sylvestris also 13 per M. of a whitish
wax, the nature of which was not more exactly determined f.

M. Fr. Nees von Esenbeck and the author examined the
milk-sap of several fig trees J, in order to find whether the
Lacca in granis could originate from trees of this genus, as is
said, but must declare it to be erroneous ; and they were in-
duced to consider, as the only plant producing this remarkable
vegetable body, the Aleurites laccifera, which belongs to a
family the chemical constitution of which allows us to infer
the presence of similar resins to that which is contained in
seed-lac.

At the same time they examined the milk- sap of Ficus
elastica from the stem as well as from the young branches; and
arrived at the result that the milk -sap of the young branches
consists of resin, gum, wax, together with some extractive
matter, a salt of lime, and a glutinous resin which was only
soluble in aether, not in alcohol, and which they believed to
be identical with the substance found by Macaire in Atractylis
gummifera, and named by him Viscin §. The milk-sap of the
old stem contained, on the contrary, caoutchouc instead of
viscin, and also the other constituent parts of the milk-sap of
the young branches, which is only observable when the milk-
sap is allowed to flow immediately into the aether. If it coagu-
lates in the air, traces only of resin, gum, and extractive matter
can be separated from the mass which has become caoutchouc
or elastic resin (Feder harz). The milk-saps of many other
species of this genus contained viscin, but in a few cases only
had it become caoutchouc in the old stems. M. Zeller ||
found this viscin also in the berries of Sambucus Ebulus.
Without doubt the seed-lac [lacca in granis) belongs to the
coagulated milk-sapswhich have been drawn from the branches
of Aleurites laccifera ? by some peculiar lac Aphis. I ex-

* Bydragen tot de naturkundige Wetenshappen, d. vii. No. 2.

t Archivfur Pharmacie, vol. i. part 1.

J Annalcn der Pharmacie, vol. xiv. part 1.

*j Memoircs de la Soc. de Physique dc Geneve, torn. vi. "Sur la Viscin," &c.

|| Wurtembergisches Correspondcnzcnblatt 1834.

158 J.C. Marquart's Report of the Progress of Photochemistry

amined it more recently with Fr. Nees von Esenbeck* and
found as its contents a peculiar wax which melts at 48° Reaum.,
and also a series of peculiar resins. The substance called the
insoluble lac-resin (lac of John) must be considered as repre-
senting the caoutchouc in this milk-sap, which resists the
common solvents, and is only affected by acidulated alcohol.
Nearly related to this is the Beta-resin of the lac, which
part the authors consider as insoluble in aether and weak al-
cohol, and only soluble in absolute alcohol, or that of 90°. By
certain manipulations it passes over into the lac of John, and
it may well be supposed that it owes its solubility in alcohol to
the so-called lac acid which is mixed with it, the nature of
which the authors were not able to ascertain on account of
its rare occurrence. That part of the seed-lac which is so-
luble in spirits of wine and aether the authors named the
Alpha-resin of the lac, and found the same to be again com-
posed of the first alpha-resin, which is hard, friable, of a gold
colour, and which gives with alkalies and oxides of lead beau-
tiful purple red combinations, while the second alpha-resin is
a yellow soft resin, and has in a very great degree the peculiar
smell of shell-lac.

Scarcely any section of the vegetable formative parts is in
greater want of a revision than that of the resins, whose dif-
fusion is so general, and whose varieties almost keep pace with
or appear even to surpass, the number of species of plants.
We are convinced that a rational examination of this part of
phytochemistry would give quite different results. In no ana-
lysis does there ever fail to be a resin among the educts enu-
merated ; even in Sphterococcus crispus M. Herberger found
two different ones, which however, as in many other analyses,
are so dubiously characterized, that we may here pass them
over in silence without keeping anything important from our
readers. Not even is a consistent division followed in the
description of these bodies; and it is probable that various
mixed and changed substances are frequently cited as peculiar
resins. We will therefore in this place only mention a few cry-
stallizing resins, like that which Mr. Landererf separated from
the liesina Guajaci tiativa, which crystallizes in fine needles,
void of smell, soluble in aether and boiling alcohol, and be-
came by concentrated nitric acid of a lively grass green colour,
and whose spirituous solution had acid reaction. A similar resin
was found by Geiger in the bark of the root of Cormisforida,
the solution of which, however, possessed neither an acid nor
an alkaline reaction. In general, those resins which are not very

• Geiger and Liebip's Ann. dcr Pharm., vol. xiii. part 3.
f Buehn. Rcpcrt., Hi. p. 1)3.

in the Year IS 35, in reference to the Physiology of Plants. 159

easily dissolved in alcohol are considered as sub-resins, with
two of which we are already acquainted as possessing a cry-
stalline nature, those from the Elemi and Euphorbium, which
are isomeric or have the same elementary composition, and
consist of 2 (C10 H16) 4- O*. The resin discovered by Boussin-
gault in the wax-like covering of Ceroxylon andicola before
cited, possesses a similar fundamental composition ; it was of a
bright white colour and crystalline, melts at above 100° centig.,
is soluble in aether, aethereal oils, and alcohol. Nees von
Esenbeck and the author found also in the bloom of the Be-
nincasa fruit a white crystalline resin soluble in alcohol, and
of a bitterish taste.

Th. Martiusf showed some time back how to prepare,
free from colour, the brown resin from the jalap root, by
treating the spirituous solution with animal charcoal; accord-
ing to his more recent experiments this decolorated resin,
having been wrapped in paper, resumed after three years its
brown colour. This colouring process appears in the course
oi' time to change the resin in the root to the state in which
we receive it ; as according to the experiments of Nees von
Esenbeck and the author, mentioned in last year's report
(p. 220), the resin which had been extracted from jalap roots
cultivated in Germany, and preserved only a short time, was
scarcely coloured yellow.

During the past year chemists have directed their attention
particularly to the cethereal oils of the black mustard-seed, and
were occupied partly on methods of preparing it, as MM.
Hesse J, Hoffmann §, Faure ||, Wittstockf, and Aschoff**.
According to most of the observers, a great quantity of aethereal
oil may be obtained from the meal of the black mustard-seed
when it has been left for some time in cold water; from which
it appears that, as in bitter almonds, not the aethereal oil but
the radical is contained in the seed. Faure observed that
tincture of galls and chlorine prevented the evolution of the
oil ; and Aschoff found that by mixing the mustard meal with
water ammonia was evolved. The produce amounted in general
to 0*9 — 1 per cent, of a colourless oil, which is heavier than
water = T002 at 14° Reaum. It is of the class of those con-
taining sulphur, and does not explode with iodine; it does how-
ever with potassium. Ammonia combines with it, and forms

* Pogpendorff's Annalen, vol. xxxiii. p. 49.

f Bnchn. Repert.,vo\. h. part 3. J Geiger's Ann., xiv. part 1.

§ Pharm. Convers-Blatt. 1835. No. 44.

|| Journ. de Pharm. Sept. 1835.

\\ Berliner Jahrbiickcr, xxxv. part 2. p. 256.

** Erdmanu and Schweigger-Seidel, iv. p. 314.

160 J. C. Marquart's Report of the Progress of Phytochemistry

a substance which has much resemblance to SidpJw-sina-
jrisin.

Bitter almonds and the leaves of the common laurel, from
which is obtained an aethereal oil containing a great quantity
of prussic acid, but which does not exist as such in the plants,
exhibit similar characters. This part of phytochemistry has
received, by Liebig and Wohler's discovery of organic radi-
cals, a direction the influence of which on many doctrines of
physiology we have yet to await. We will here only mention
as an instance the recent experiments of M. Winckler* on
the products by distillation of bitter almonds and the leaves of
the common laurel, and briefly remark that the aethereal oil of
these bodies is a combination of benzoyl (the radical consist-
ing of C14 H502) with hydrogen; at the same time with this
benzoyl hydruretted an evolution of a cyan-benzoyl takes
place on distillation, which is the cause of the oil of bitter
almonds containing prussic acid, and which may be separated
from it. Proctorf found an oil similar to the oil of bitter
almonds in the bark of Prunus virginiana.

M. PagenstecherJ extracted from the flowers of Spircea
Ulmaria a very remarkable aethereal oil, heavier than water,
of a yellow colour, and of a peculiar smell similar to prussic
acid. Its peculiar constitution is evident from the property
of its spirituous solution, which becomes of a cherry-red co-
lour when mixed with chloride of iron. Caustic alkalies form
with it yellow combinations, in consequence of a peculiar acid
which accompanies the oil, and by which it is connected
with valerian oil, cinnamon oil, and the heavy oil of pinks.
M. Lowig§ examined the oil further, and regards it as the
combination ofspiroil (a radical of C12 H10 04) with 2 M. G.
hydrogen, but the spiroilic acid as the combination of spiroil
with 4 M. G. oxygen. The Spircea oil solidifies at —20° and
boils at +85°.

Several aethereal oils were prepared and closely examined ;
one from the fruit of Coriandrum sativum by TrommsdorfF|| ;
it was colourless, and the spec. grav. was 0*859. M. Bleylf
analysed the plant, flowers, and fruit of Achillea nobilis. The
aethereal oils from the plant and the seeds were alike, of spec,
grav. 0*970, and of a butter-like consistence ; that however
from the flowers was of a thin liquid consistence, and spec.

• Buchn. Repert., vol. Hi. p. 289. f Journ. de Chim. Med. 1834.

I Buchn. Repert., vol. ix. p. 337-

$ PoggendorfTs Annalen, vol. xxvi. p. 383 ; and Scientific Memoirs,
vol. i. p. 153.

|| Archiv fur die Pharmacie, ii. p. 113.
% Archiv fur die Pharmacie, vol. i. ii. mil .

in the Year 1835, in reference to the Physiology of Plants. 161

grav. 0*983. All three did not fulminate with iodine. It is
astonishing that the oils from the fruit and the flowers did not
coincide more, since it is certain that in the distillation of the
flowers M. Bley did not separate the germen. We therefore
doubt the correctness of the statements, as in other respects
the experiments of M. Bley have been conducted rather care-
lessly, which has been lately proved by all the analyses of
Achillea nobilis. M.Landerer* prepared from the green part
oiConium maculatum a small quantity of aethereal oil, in ob-
taining which no one had before succeeded in Germany.
Does the hemlock which grows in southern latitudes (in
Greece) form an exception ?

James Martin f obtained from the leaves of Cassia mary-
landica also an aethereal oil, as did Zeller % from the peri-
sperm of Abies yectinata. The latter • was limpid, spec,
grav. = 0*839; fulminated with iodine, but left potassium un-
changed ; it therefore contained no oxygen. The aethereal oil
from the leaves of Myrica Gale§ solidifies, according to Ra-
benhorst, at 14° Reaum., and is at 15° a thickish dark yellow
mass, which contains 70 per cent, of stearoptin. It does not
fulminate with iodine, and has a spec. grav. = 0*876.

Elementary analyses have conducted us in the aethereal oils
to very interesting results, and have made known to us, be-
sides those oils accompanied by acids and sulphur and which
have been mentioned above, a series of oils containing no
oxygen, therefore containing only carbon and hydrogen ; and
another series containing carbon, hydrogen, and oxygen.
To the first series belongs the oil of turpentine, consisting of
C5 H8; and the oil of the black pepper, the juniper oil, the
savin oil, and according to Dumas || the oil of the fruits of
Citrus medica and Citrus limetta have been found to be isomeric
with it. In addition to these, posssesing the same combina-
tions, are the light parts of the oils of pink and valerian,
which on their separation were also accompanied by a pecu-
liar acid : further, the copaiva balsam oil, the basis of the ca-
jeput oil, and of the turpentine-camphor; the cajeput oil is
a hydrate, whose base, like that of the. turpentine oil, consists
of C5 H8: the turpentine-oil-camphor is another hydrate of
this turpentine oil, which often separates itself from it in cry-
stals. Colophony, copaiva resin, camphor, the caryophylline
and lavendel-stearoptin have been acknowledged to be oxides

* Buchn. Repert., vol. in. part 1.
t The American Journ. of Pharm., 1835. April.
X Archiv fur Pharm. , vol. iii.
§ Berliner Jahrbiicher, vol. xxxv. part 2. p. 256.
|| Journ. de Chim. Med., June 1835.
Third Series. Vol. 11. No. 66. Aug. 1837. Y

162 J. C. Marquart's Beport of the Progress of Pkytochemislry

of turpentine oil. The camphor oxide obtained by the distil-
lation of the roots of Iris for entina, and which is crystalline,
laminated, and of a pearly lustre, consists of C4 H8 O, and is
therefore to be regarded as an oxide of oil of roses, C4 H8 .
Till now the attempt to isolate the odorous principle from
several strongly and agreeably smelling flowers has proved
unsuccessful. Among these is the Narcissus Jonquilla, which
Robiquet* examined, and from which, by extraction with sul-
phuric aether, he obtained a yellow aethereal oil, which is very
volatile, and when once volatilized is not easily condensed.
It decomposes very easily, even in closed vessels; it becomes
solid, and then scarcely melts at 100° centigr. and is a warty
mass void of smell, which separated itself already with the
aethereal oil, after evaporation of the aethereal extract. M. Her-
bergerf obtained from the flowers of Convallaria majalis a
small quantity of a camphor-like substance, in part of a ra-
diated crystalline structure and possessing a very strong
smell.

What was formerly considered as benzoic acid in the flowers
of Melilotus is, according to GuillemetteJ, similar to the sub-
stance from the tonquin bean which has been named Couma-
rine, and De Candolle mentions it in his Physiology (p. 352,
Paris, 1832) under the hyperhydrogenic substances. It be-
longs rather, according to our views, to the camphoroids, on
account of its volatility ; it crystallizes, melts, volatilizes, dis-
solves in boiling water, in alcohol and aether. According to
Henry, coumarine from the tonquin bean, as also from the
Melilotus, consists of C5 H6 02 .

We have in general very little to remark on the fat oils, and
confine ourselves to the relation of their occurrence in various
plants, according to the observations of last year.

M. TrommsdorfF found § in the fruit of Conundrum sativum
13 per cent, of a fat oil insoluble in alcohol. It was void of
smell, grayish green, thickish, and was easily decomposed into
almost equal parts of stearine and elaine. J. Martin || found in
the leaves of Cassia marylandica a yellow fat oil, and a simi-
lar oil was found by Ch. Schreevef in the bark of the root of
Gillenia trifoliata. Semmola** determined the contents of the
white fat oil in the tubers of the root of Cyperus esculentus to
be 48 per m., and Fleuron found fat oil in the roots of Astra-
galus escapus; M. Zenneck found in his analysis of the fruit

* Journ. de Pharm., July 1835.

t Buchn. Repert. vol. Hi. \ Journ. de Pharm. April 1835.

$ Archwf'ur Pharm., ii. 2.

II The American Journ. of Pharm. April, 1835. f Ibid.

•• Journ. de Chim. Med. 1834.

in the Year 1835, in reference to the Physiology of Plants. 163

of Panicum miliaceum* 4*37 per cent, of a green fat oil, 2 per
cent, of which was contained in the pericarp, and 2*37 per
cent, in the albuminous body. Millet, therefore, in this re-
spect surpasses the oat and rice.

Th. Martius f found in the seeds of Strychnos Nux vomica
0*5 per cent, of an oil soluble in alcohol. The fat from the
seeds of the East Indian species ofBassia, B.latifolia, butyrea,
longifolia, of the family of the Sapotea?, which belongs also here,
is, according to C. Henry :f, of a dirty yellow colour, and pos-
sesses an aromatic taste and smell. M. Koene extracted from
the roots of Anacyclus Pyrethrum § two fat oils, one of which
was soluble in oil of turpentine and alcohol, the other not.
In the above-mentioned investigation of the flowers of Nar-
cissus Jonquilla M. Robiquet also found an oil of some con-
sistency belonging to this division, smelling something like fish-
blubber. The albuminous body of Abies pectinata contains,
according to Zellerjj, a drying oil, soluble in alcohol, whose
spec. grav. was 0*913 ; and M.Wurzer found in the same organ
of Pinus pinea a fat oil, void of smell, and which did not dry
upif . J. Cockburn also found in the bark of the root of Cornus
florida** a fat oil soluble in alcohol and in aether.

The acids are a class of vegetable substances which are as
widely diffused as the resins ; they have however occupied
the attention of chemists more than the latter, so that we are
scarcely able to give more than the newly-discovered occur-
rence of the most important acids in individual plants. Among
others, gallic acid was found by M. Aschoffff in the leaves of
Rhus Toxicodendron ; by Cockburn %\ in the bark of the roots
of Cornus for ida ; by Joh. Tilhgmann§$ in the roots of Ci-
micifuga racemosa; and by Proctor in the bark o{ Prunus vir-
giniana.

It was formerly believed that the process of the formation
of mould increased the quantity of gallic acid, whence it might
be inferred that this acid was a product; the experiments of
Winckler||[| are opposed to this, although Aschoff states that
he found a far greater quantity of gallic acid in the mouldy
extract of the leaves of Toxicodendron than in the fresh sap.

* Buchn. Repert., vol. lxix. f Ibid., vol. li. part Hi.

X Journ. de Pharm., Oct. 1835.

§ Ann. de Chim. et de Pht/s., July 1835. || Archiv fur Pharm., vol. iii.
<fl Buchn. Repert. , vol. xlix. p. 303.
«• The American Journ. of Phann., July 1835.
ft Archiv fur Pharm. vol. i. part 2.
H The American Journ. of Pharm., July 1835.
§§ Journ. de Chim. Med. 1834. November.
|| Buchn. Report., vol. li.

Y 2

1 64- J. C. Marquart's Report of the Progress of Pkytochemistry

The peculiar substance of the Catechu prepared from the
Nauclca Gambir is, as confirmed by Pfaff *, identical with the
tannic acid of Biichner. It dissolves easily in boiling water, less
so in cold ; the solution acts as an acid, becomes yellow when
exposed to the air, colours solutions of iron green, and does
not precipitate gelatine: it consists of C18 H8 08 .

The peculiar acid fu mar acid, discovered by Winckler in
Fumaria officinalis was subjected by Horace Demarcay f to an
elementary analysis, and was found to be isomeric with the
paramalic acid, which, as is known, is a product of the de-
composition of malic acid.

M. Geiger found in the bark from the roots of Cormisflorida,
an acid, cornic acid, which contained no nitrogen, was cry-
stalline, easily soluble in water and alcohol, and possessed a
bitter taste. The shiller substance (Shillerstqjff) found in the
bark of several dicotyledonous trees was more accurately ex-
amined by M. Trommsdorff, sen.:f: its properties indicate
that it belongs to the class of acids. Trommsdorff, jun., found
it to consist of C8 H9 Os .

M. Trommsdorff, jun. §, found in the so-called wormseed
(the fruit-bearing calathiae of Artemisia glomerata,) pure acetic
acid; and M:Radig|| found 11 per cent, of acetic acid combined
with potash in the leaves ot Digitalis purpurea. M. Bleylf
affirms that he found in the herbaceous part as well as in the
flowers and seed of Achillea nobilis acetic acid containing
formic acid ; we have however reason to doubt the truth of
this. We have already mentioned in speaking of the aethereai
oils the acid from the flowers of Spiraea Ulmaria.

M. H. Trommsdorff ** lately examined the sylvic acid found
in the resins of pines, and which was formerly considered,
without any reason, as an oxide of oil of turpentine; according
to M. Trommsdorff it is rather the oxide of a radical of Cl0
H15. It crystallizes in large colourless rhomboidal tables,
and melts at 120° Reaum. M. Liebig,who examined the other
part of the colophony resin, the pinic acid, found it to have
the same composition, by which the isomery of both has
again been confirmed.

M. Voget found ff in the dried leaves of Asperula odorata

• Pfaff's Mittheilungen aus dem Gebiete der Pharm., etc. vol. i. part 3, 4.

f Ann. de Chim. et de Physique, August 1835.

% Geiger and Liebig's Ann. der Pharm., vol. xiv. part 2.

§ Annalen der Phannacie, vol. xi. part 2.

|| Pharm. Novellcn von Ehrmann, 1834, part 2.

f Brand, Archivf. d. Pharm., vol. i. ii. and iii.

** Geiger and Liebig's Ann. der Pharm., vol. xiii.

ft Archiv fur Pharm., vol. iii.

in the Year 1 8 35, in reference to the Physiology of Plants. 165

benzoic acid; and M. Landerer* extracted from the roots of
Inula Helenium scales similar to sebacic acid, which possessed
a pearly lustre, were soluble only in Aether and caustic potash,
and devoid of smell and taste; the solution acted as an acid.
Dumas describes a similar crystalline formation, which could
be seen with the naked eye in the form of warty excrescences
in the interior of the above-mentioned rootf? which consisted
ofC7H90.

Prussic acid was found by ProctorJ in the bark of Prunus
virginiana, and by O. Henry § in the sap of the root of
Jatropha Manihot, or at least, as in most cases, a radical from
which it might be formed.

Between these azotic acids and the alkaloids must be
placed, on account of their containing nitrogen a division
of vegetable formative parts, which for this reason have
been termed indifferent, and among which many substances
too little known have been classed : the following however have
found their right place. Emetine may, according to Lan-
derer ||, be prepared in small white cubical crystals, the solu-
tion of which acts as an alkali and is precipitated by tincture
of galls ; it must for this reason take its place in the following
division, the alkaloids. The microscopico-chemical experi-
ments on the pollen by M. Fritschef have further shown that
the Pollenin of authors deserves no place amongst the proper
vegetable formative parts, being unaltered pollen, from the
epidermis of which several soluble substances were extracted
by means of various solvents, while the contents remained un-
changed. He made his experiments with the pollen of Corylus
Avellana. What was formerly described in this division under
the name of Asparagin is, according to the experiments of
MM. Wittstock, Regimbeau**, and Schmidt ff, confirmed to
be aspartate of ammonia, and is not contained as such in
the roots of Althaea officinalis, nor in the young sprouts of
Asparagus officinalis or acutifolius, but is a product of decom-
position. The latter found this salt in the sap of the leaves
of Atropa belladonna which had been evaporated to consist-
ence. The bitter substance from Cetraria islandica may be
justly considered to belong to this division. Rigatellijj: has
described a method of preparing this new substance in cry-

• Buchn. Repert.y vol. xlix. p. 275.

f Journ. de Chimie Med. June 1835. J /bid., 18.34.

§ Journ. de Pharm., 1834. Nov. |j Buchn. ReperL, vol. Hi.

% PoggendorfF, Annalen, vol. xxxii. n. 31.

** Journ. de Pharmacie, 1834. November.

ft Anna/, der Pharm., vol. xii.

XX Gazetta eclett. di Farmacia, 1835. Nov. 11 et 12.

1 66 Professor Forbes's Experiments on

stals, which dissolve in water and in alcohol,- but not in a?ther,
and the solutions of which are thrown down as a red precipi-
tate by iron and its salts.

[To be continued.]

X X. Account of some Experiments made in different Parts of
Europe, on Terrestrial Magnetic Intensity, particularly with
reference to the Effect of Height. By James D. Forbes,
Esq., F.R.SS. L. $■ E., fyc, Professor of Natural Philosophy
in the University of Edinburgh.

[Continued from p. 66, and concluded.]

18. V. Variations in the Needles' Magnetism. — In all obser-
vations of this kind, this change gives rise to the most trou-
blesome errors. The mode of ensuring an equable magnetic
state is unknown, though an approximation may generally be
obtained to it. Of the two needles sent to this country in
1827, by Professor Hansteen, one (No. 1.) has, after some
slight variations, become almost stationary in its magnetism ;
the other " Flat'' has been continually diminishing in intensity.
We have seen in the last article that the earth's magnetic ac-
tion, varying continually and being unknown, we can only
properly compare observations made at the same time of the
year, and of the day. The progress of change in the needles
may be traced by the following tables*.

Table IV.

NEEDLE, No. 1.

Place.
Makerstoun,

Date.

Observer.

Log. Time
300 Vibrations.

Log. Ratio of
AnnualChange

1829, Jan. 20, 3h

1830, Jan. 23, 3h

Dunlop.

2 90251 V
2-90248 J

•99997

Edinburgh,

1829, July 9, llh

....

2-90765 1

•00043

1832, June 2, llh

Forbes.

2-90890!
2-90849*

•99956

1833, May 7, 5h

....

1835, May 4, 1"

....

2-90915}

•00066

Paris, .

1833, June 11, lh

....

2-87102 \ .
2 87092 J

•99995

1835, June 13, 4*

....

The differences since June 1832 are probablj

r imputable to

the horary

variations alone.

* The mutual action of the needles is a point of importance. Before
they came into my possession they were kept in their separate cases, but
without further attention, being packed together in the same external case

Terrestrial Magnetic Intensity.
[TABLE IV. continued.']

167

FLAT NEEDLE.

Place.

Date.

Observer.

Log. Time
300 Vibrations.

Log. Ratio of
AnnualChange

Makerstoun,
Edinburgh,

Paris,

1828, Dec. 1, 12h
1830, Feb. 14, 3**

1829, July 9, 10h

1832, June 2, 12h

1833, May 7, 5&
1835, May 4, 2h
1833, June 11, 2h
1835, June 13, 4h

Dunlop.
Forbes.

3-00582 \
301435 J
301240}
302923 {
303607'
304579}
2-99871 \
300869 J

•00707
•00546
•00736
•00488
00500

19. In the case of No. 1, the magnetism has been consi-
dered as stationary throughout the period 1832-1835, with
which we are now concerned. In the case of the Flat Needle,
this cannot be assumed, nor can we admit the change to have
been uniform. It seems probable that much movement, and
especially alternations of temperature, accelerate the loss of
magnetism, that loss having been greatest in 1832, when most
of the following observations were made. This is t^nfirmed
by a more minute inspection. Observations were made at
Geneva on the 20th August 1832, and again on the 10th
November, and between these dates the whole of the alpine
series is contained : Now the variation of the logarithms for
that period is no less than '00452, or at the rate of '02001
per annum ; whilst we have seen that during the period from
June 2, 1832, to May 7, 1833, which includes the above, the
mean change was only at the rate of '00736 per annum. It
is clear then that, in order to render the observations of 1832
comparable with one another, we must assume a much higher
rate than the mean, for the months from June to November.
Admitting some little doubt as to the Geneva comparisons
due to the monthly change of intensity, and the great differ-
ence of temperature in the two cases ; I think that I shall best
satisfy the conditions by assuming the log. time to have in-
creased by '00100 for each month from June to November,
leaving -00684. — '00500 = '00184 for the whole of the remain-
in which they came from Norway. This arrangement I have not changed,
but in packing them I have taken pains to place the opposite poles nearest
one another, an arrangement which seems to have been attended with
good effect; and to show that needles may lie within an inch or two of one
another without material injury, when we see the stationary condition of
No. 1, and the diminishing rate of variation of the "Flat" Needle.

168 Professor Forbes's Experiments on

ing six months down to May 1833, during which the needle
was in a state of almost perfect repose.

20. The mode of allowing for this is the following. All
determinations of intensity are relative, referring to some in-
tensity as a standard ; but I have taken the horizontal inten-
sity at Paris as unity (which is to that at the magnetic equator
as 4,788 to 10,000 according to Humboldt)*. Hence, since
the squares of the times of 100 vibrations are inversely as the
magnetic forces, the terrestrial horizontal intensity at a station
A is to that at Paris, or 1, as the square of the time observed
at Paris (which time we may call TP) is to the square of the
time observed at station A (or TA). Hence,

Intensity at K = t~\

If the magnetism of the needle change, we must therefore
find by interpolation the time of vibration at Paris for the
particular epoch of observation.

21. In the case of Needle No. 1, the magnetism being sta-
tionary, the time of 100 vibrations has been assumed from an
observation made (in M. Arago's Cabinet Magnetique), 11th
June 1833, as equal to

247 sec70; its log. 2*39392

22. In the case of the " Flat" needle, a subsidiary table has
been calculated of the times for Paris, cor responding to the epochs
when observations were made elsewhere, which appear amongst
the details to be given in the sequel. On the 11th June 1833,

the log. time of 100 vibrations at Paris was 252 159

If, for the period from June 1832 to May 1833, we

deduct -006 184 (by Art. 18) and for the month of
May 1833, *00040 being the rate of change for the
current period (Art. 18), we have a change for one
year, subtractive, *00724

TF, or Time at Paris, June 11, 1832, Log. 2*51435
Adding -001 per month as] , ^^

proposedmArU9,weshall ^.n 2.51635

have nearly these values |s?t#n> .2-51735

(neglecting trifling quanti- { Q*L „. ^^^

ties) as approximations to N » 2.519*5

the value of Log. TP J WOV-4S ^5193^

* Deduced from the measure of total intensity 1-3482 at Paris, given in
the Memoires (TArceuil, torn. i. multiplied bv the cosine of the dip, there
alto given (69° 12').

Terrestrial Magnetic Intensity. 169

Proceeding similarly with the mean (and very regular)
ratios of change in Art. 18, we shall find

fl833, May 7, 2*52114

I 1835, May 4, 2-53100

Log. TP< ... July 20, 2-53203

| ... July 30, 2-53216

L .- Aug. 10, 2-53230

23. The various corrections now considered being fixed,
the application of them, and the deduction of the horizontal
intensities related to Paris as unity, becomes easy. I have
employed printed forms for this purpose, arranged in pages
each containing 5 reductions after the following model, and
bound up in books.

MAGNETIC INTENSITY.— Horizontal Needle, No. l.

Place,

Date,

Mean Time,.. ..

No. of Vibra-"\
tions observed. J

Geneva. Botanic Garden.

Geneva. Botanic Garden.

1832, Nov. 10.

1832, Nov. 10.

11^33™

llM2m

100

100

Arg.

Log.

Arg.

Log.

2-38021
9-99990

9-99967
9-99863

Observed Time.

Kate Chrono- )

meter \

Arc, . . * |

Temperature, . .

240-14

+2P

oc= 10° \

w = 110°/

7°-0 R.

2-38046
9-99990

9-99967
9-99863

240-00

+ 21s
<*.— 10° \

?H = 110OJ

7°-0 R.

Corrected Time )

TimeatParis(Tp)
T„

239-14

2-37866
2-39392

239-06

2-37841
2-39392

0-01526

2

0-01551

2

T

/T \2=Inten-\
\T,,/ sity. J

1-073

1-074

0-03052

0-03102

i

*a=Initial semi-arc of vibration ; ?»=number of vibrations which reduce

Third Series. Vol. 1 1. No. 66. Aug, 1837.

1 70 Professor Foi bes's Experiments on

§ 3. Observations on Magnetic Intensity.

24. It now remains to give the observations which have been
made, and reduced in the way already detailed. These con-
sist chiefly of two series. One was made in the year 1832,
intended to form part of a very general investigation in physical
geography, which I meant to pursue throughout a journey of
several years. Having been diverted from this by the opening
of other prospects, the series remains incomplete as a general
investigation, but embraces a connected examination of a great
district of the higher and central Alps, calculated to elucidate
a question which I had particularly proposed to myself, as to
the supposed diminution of magnetism with height. It like-
wise includes some observations as to the influence of extinct
volcanos on the Rhine. The second series was made in the
Pyrenees in 1835, with almost an exclusive view to the in-
fluence of height, and is confined to one small district. One
other important point gained was a very accurate determina-
tion of the comparative horizontal intensities at Edinburgh
and Paris. The choice of the stations was regulated very
much by the views just mentioned : the particular spots of ob-
servation, together with the geographical position and eleva-
tion of the place, will be given in Table VII. I have thought
it better to record in the first place in separate Tables for the
two needles, the details of the observations in the order in
which they were made, the data for correction, and the cor-
rected numbers. These are contained in Tables V. and VI.
I have thought it needless to incur the labour and expense of
printing the individual numbers on which the mean results
are founded. They are however preserved in a condition
adapted for immediate reference*.

* Many of the numerical calculations contained in the remainder of
this paper, have been made by two of my pupils Messrs. Irvine and Edward,
under my own inspection and revision.

Terrestrial Magnetic Intensity,

171

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[ 175 ]

XXI. On Murio-carbonate and Native Muriate of Lead.
By H. J. Brooke, Esq., F.R.S., $c*

\ SPECIMEN I obtained some time since from Cornwall
■** contains both these substances. I have not observed any
specimen of either of them in any of the collections that I
have seen in Cornwall, nor am I aware of the existence of
any others from that country, except a few single crystals of
the murio-carbonate in the collection of the late Wm. Phillips,
which came into his possession after the publication of his
" Mineralogy."

The figure and measurements of this mineral given in page
343 of his work (edition of 1823)f do not afford data for
ascertaining the dimensions of the prism.

I annex a figure of one of the crystals from Cornwall, from
which those elements may be deduced.

The primary form is well known to be a square prism, and
from the inclination of P on a, the ratio of a terminal edge to
a lateral edge is found to be as 35 to 38 very nearly. There
are bright cleavages parallel to all the primary planes and to
both the diagonal planes of the prism.

The symbols of the planes are A A2 G G
The planes being a b d e

M

\^y

P, M = 90°
P, a = 123 6'
P, b = 112 22
M, a = 126 20
M, b = 145 47
M, d = 1 35
M, e = 153 26

Count Bournon gives 121° 52; as the inclination of P on

* Communicated by the Author.

f I cannot without injustice to the memory of my late friend William
Phillips refer to the recent edition of his Mineralogy, alterations of such
a nature having been made in it as to render it no longer his woik.

The editor admits in his preface*, with equal candour and truth, his in-
capacity to do justice to the work, as indeed is apparent throughout the
book, for he has not only omitted to correct any of the errors, as far as
I have observed, but he has interpolated many additional mistakes, and in
a manner which might lead any reader to suppose them the blunders of
the author. Several however of these the editor might have avoided by
using the ordinary diligence of a compiler.

The second angular measurement given in the work, Pon g 1 of quartz,
is more than 30° wrong, by a mistake of W. Phillips in copying from Haiiy,

176 Dr. Flare on certain Points

some plane, probably a. The planes of the crystal I have
measured are brilliant and perfect, several of the measured
angles having agreed exactly with the calculated ones.

The muriate or chloride of lead occurs on r.iy specimen in
the form of very thin and irregularly curved translucent cry-
stals, without any well defined lateral or terminal planes.
The colour is yellowish white.

The transparent and colourless crystals described as anti~
monial phosphate of lead from Horhausen on the Rhine, have
the form and angular measurements of phosphato-arseniate of
lead; but on examination they appear to consist wholly of
chloride of lead, H. J. B.

XXII. On certain Points of Chemical Philosophy and Nomen-
clature. By Robert Hare, M.D., Professor of Chemistry
fit the University of Pennsylvania ; with a Letter from
M. Berzelius.

[To the Editors of the American Journal of Pharmacy. ,]

Dear SlRS, Philadelphia, March 4, 183/.

IN September, 1833, I published in your Journal, together
with some encomiums upon the Treatise of Chemistry by
the celebrated Berzelius, certain objections to his nomenclature,
and some suggestions respecting a substitute, which I deemed
to be preferable. In the following June I addressed a letter
to Professor Silliman upon the same topics, in which my cri-
ticisms and suggestions were amplified and corrected in obe-
dience to more mature reflection. A printed copy of that
letter having been sent by me to Berzelius, I received in an-
swer an epistle, of which I furnish you with a translation.

and there are in other places, in Rutile, for example, impossible values of
angles given, through the inattention of the author in copying from his
rough memorandums, hut which a very slender knowledge of the subject
would have enabled the editor to set right. His omissions, however, in
this respect would be less injurious to the reputation of the author than
the altered and interpolated passages. In sulphuret of copper, for in-
stance, the author gives & regular six-sided prism, either simple or modified,
as the crystalline form, but the editor has inserted that the primary form
is a cube. Now an editor so little acquainted with mineralogy as not to
know that a cube cannot be the primary form of a regular six-sided prism,
ought not to have attempted any alteration in W. Phillips's text, but should
have reprinted it exactly as it stood, and have placed any additions of his
own in an appendix.

* We reprint this article at the request of our friend Dr. Hare.— Edit.

of Chemical Philosophy and Nomenclature. 177

Since the period of that correspondence, so demonstrative
of candour and good feeling on the part of the great Swedish
chemist, I have published two editions of my Compendium of
Chemistry, in which I have pursued a course corresponding
with my criticisms above alluded to. I am therefore desirous,
in addition to the letter of Berzelius to lay before the public
a recapitulation, review, and an additional explanation of the
grounds upon which I have ventured to employ a language,
and an arrangement inconsistent with the practice and opi-
nions of a chemist by whose authority in other respects I am
usually influenced. But before proceeding with the ungracious
task of endeavouring to establish the correctness of my views
in opposition to those of my friend, I feel that it will be no
more than justice to repeat an acknowledgement, already made
in my text book, that if De Bonsdorff, myself, and others are
right in considering the double salts of Berzelius as simple salts,
it is to the light afforded by his investigations, that we owe the
power of seeing the subject correctly. I believe the idea, that
any other body besides oxygen could produce both acids and
bases capable of forming salts, originated with Berzelius, in
the instance of sulphur.

Recapitulation and Review of the Grounds of his deviating

from the Language and Arrangement of Berzelius, and other

distinguished Chemists; with some additional Explanations

and Suggestions, by R. Hare, M.D., Professor of Chemistry

in the University of Pennsylvania.

According to the Berzelian nomenclature, bodies which
produce salts by a union with radicals are called halogen or
salt producing bodies, while those which with radicals form
both acids and bases, capable by their union of constituting
salts, are called amphigen bodies or both producers. Salts,
produced by the first mentioned class are called haloid salts;
those produced by the other are called amphide salts.

I objected to this classification, that the words salt, acid
and base, were broad, vague and unsettled in their acceptation,
having, by chemists in general, and especially by Berzelius,
been employed to designate substances differing in composi-
tion, and extremely discordant in their properties ; that no
method of defining a salt had been devised, which had not
been founded either on properties or composition ; that in the
nomenclature of Berzelius properties were disregarded, since
among his haloid and amphide salts were found substances
differing extremely in this respect. Thus, for instance, com-
mon salt, Glauber's salt, Epsom salt, vitriolated tartar, and
cream of tartar, were associated with the fuming liquor of

Third Series. Vol. 11. No. 66. Jug. 1837. 2 A

178 Dr. Hare and M. Berzelius on certain points

Libavius, the butyraceous chlorides of zinc, antimony, and
bismuth, plumbum corneum, luna cornea, fluor spar, and the
acid fluorides of silicon and boron. I objected also that com-
position could not be resorted to consistently with his classi-
fication ; since, agreeably to it, a salt might be either a binary
compound of a halogen body with a radical, or consist of
two binary compounds, each containing the same amphigen
body.

To the terms acid and base, as employed in his nomencla-
ture, 1 objected, that neither by the celebrated author, nor by
any other chemist, had any definition been adhered to which
could, consistently with his plan, restrict the meaning of those
appellations to the binary compounds formed by the union of
his amphigen bodies with radicals.

Acidity and basidity* had sometimes been distinguished by
an appeal to properties, sometimes to composition, but to
neither had there been any consistent attention. In order to
demonstrate the total neglect of properties latterly displayed,
it was only necessary to contrast substances bearing generally
the name of acids; as for instance sulphuric acid with rock
crystal, acetic acid with tannin, and prussic acid with margaric ;
or to contemplate simultaneously the admission of the hydr-
acids formed with the halogen bodies into the class of acids,
while alleged incapable of combining with bases, with the ex-
clusion from that class of nitrous acid, upon the plea of the
same incapacity.

In reference to neglect of composition in forming the class
of acids, it will be sufficient to advert to the association in that
class, of compounds formed with radicals both by the halogen
and amphigen bodies; so that the halogen bodies are in one
case producers of salts, in the other producers of acids; in
one case act as supporters, acidifiers, or electro-negative prin-
ciples, in another as radicals to the comparatively electro-posi-
tive hydrogen, pre-eminently a radical by the definition of that
word given in the treatise of the distinguished author of the
nomenclature.

After stating my objections to the basis of the Berzelian
nomenclature, I proceeded to mention those to which I con-
sidered the superstructure as liable.

Having designated the acid compounds of his amphigen
class, by prefixing syllables indicating their electro-negative
ingredients ; having also in some instances, as in those of the
fluosilicic, and fluoboric acids, adopted this course in relation

* For the use of the words basidity and salidity, I have no authority;
but conceive that through their analogy with acidity their meaning is so
obvious a» to make it expedient to employ them.

of Chemical Philosophy and Nomenclature. 1 79

to halogen bodies; I objected to the use of the word hydracid,
in which the electro-positive radical is made to act as if co-
ordinate with oxygen.

Moreover, the termination in ide having been generally at-
tached to the electro- positive compounds of oxygen, acting as
bases, I condemned the employment of that termination, to
distinguish the electro-negative, and acid compounds of sul-
phur, selenium, and tellurium. I considered it inconsistent
to give precedence to the syllable designating the radical in
the acids formed with hydrogen ; as in hydrochloric, hydro-
bromic, hydriodic, hydrofluoric, hydrofluoboric, hydrofluo-
silicic, preferring the terms chlorohydric, bromohydric, iodo-
hydric, fluohydroboric, fluohydrosilicic, &c, in which I have
been sanctioned by Thenard and others.

I proposed a definition of an acid, and a base, which I con-
ceived to be the only one which could be adopted, consistently
with the use made of those words by Berzelius, and other di-
stinguished chemists; and advanced that, agreeably to that
definition, his double haloid salts must be considered as simple
salts, severally formed of an acid and a base.

I objected to his treating the words combustion, and oxy-
genation as synonymous.

Having thus made the reader acquainted with the substance
of my criticisms upon the Berzelian nomenclature, I will sub-
join his letter in answer to them, and will then state, and en-
deavour to justify, the conclusions at which I have arrived.

Letter from J. J. Berzelius of Stockholm, to R. Hare, M.D.9
Professor of Chemistry in the University of Pennsylvania,
acknowledging the receipt of a Communication respecting
Nomenclature, and replying thereto.

Sir, Stockholm, Sept. 23, 1834.

I am very much obliged to you for the remarks, which,
under the date of June 21st, you had the friendship to com-
municate to me, respecting the nomenclature which I have
employed in my Treatise of Chemistry.

I perceive that having contemplated chemical phaenomena
under different points of view, we differ as to the nomencla-
ture which is the most appropriate for their description. I
consider the combinations of metals with chlorine, bromine,
&c, as salts; whilst you, in accordance with Mr. De Bonds-
dorff, consider them as bases and acids, capable of forming
salts by their union.

If it were expedient that chemical classification should be
dependent on the number of simple bodies which enter into

2 A2

180 M. Berzelius on certain points

each combination, this idea of Mr. De Bondsdorff would
without doubt be preferable; but if attention be due to the
chemical properties which characterize combinations, we can*
not adhere to an arrangement founded on the number of the
elements. Yet so essential is it in chemistry to have reference
to properties, that a system of chemistry in which common
and analogous properties should not affect the arrangement,
would present a mass of facts so chaotic, that no memory
would be competent to retain them. In a system thus strictly
conformable to the ideas of Mr. De Bondsdorff, cyanogen,
though in its properties resembling chlorine or bromine which
are simple bodies, ought to be considered, also, as a base or
as an acid having azote for its radical — I am persuaded you
would not approve of extending the system of De Bondsdorff
so far; but if it be correct, it would be inconsistent not to
make this extension.

But let us return to the combinations of the metals with
chlorine, fluorine, &c, and make, in imagination, the following
experiment. Let us take two portions of caustic potash, a
base in which the basic characters are more striking than in
any other. To one, let us add a sufficiency of sulphuric acid
to extinguish entirely its basic property; we shall then have
a neutral body of a saline taste. You will admit it to be a
salt. Now let us add to the other portion, hydrofluoric acid.
At a certain point the basic properties of the potash will dis-
appear, and we shall have a resulting compound quite as
neutral as the sulphate of potash, endowed with a saline taste
entirely analogous to that of the sulphate. The basic pro-
perties of the potash are destroyed by the hydrofluoric acid,
as well as by the sulphuric acid. But you will allege the re-
sulting combination is not a salt, but a base which has ex-
changed one basifier (oxygen) for another basifier (fluorine).
In proof you may add as much more hydrofluoric acid, which
combining with the new base will form with it a crystallized
salt. But this salt is not neutral, it has almost the same acidity
of taste as the hydrofluoric acid employed. The new base
does not destroy then the acid reaction.

Let us make a further addition of sulphuric acid to the sul-
phate of potash. A salt equally acid will result, in which the
sulphate of potash acts the same basic part towards the sul-
phuric acid, as the fluoride of potassium towards the hydro-
fluoric acid. Should it be desired to extend the comparison
further, it will be found that for each less electro-positive
fluoride, susceptible of combination with the potassic fluoride,
there will be, with but very few exceptions, a corresponding

of Chemical Philosophy and Nomenclature. 181

sulphate, susceptible of combination with the sulphate of
potash. The analogy is then complete, it exists not only in the
perfect neutrality of the two potassic salts, in their saline
taste, but also in their manner of forming combinations with
other bodies; notwithstanding one of them, the sulphate, con-
tains one element more than the other. If, instead of potash,
potassium were employed to saturate our two acids, the ana-
logy of the operation in both cases, would be still more com-
plete. The same quantity of metal would displace equal
volumes of hydrogen. When the visible results of our ex-
periments are so perfectly analogous, it is to be presumed that
the invisible process which we do not see, may also be per-
fectly analogous, and that if facts exactly alike are explained
differently, there must be a defect in the explanation. If, for
instance, the true electro-chemical composition of the sulphate
of potash should not be KO-f SO3, as is generally supposed,
but K + SO**, and it appears very natural that atoms, so
eminently electro-negative as sulphur and oxygen, should
be associated, we have, in the salt in question, potassium
combined with a compound body, which, like cyanogen in
K + C2 Nf, imitates simple halogen- bodies, and gives a salt
with potassium and other metals. The hydrated oxacids,
agreeably to this view, would be then hydracids of a compound
halogen body, from which metals may displace hydrogen, as
in the hydracids of simple halogen bodies. Thus we know that
SO3, that is to say, anhydrous sulphuric acid, is a body whose
properties, as respects acidity, differ from those which we
should expect in the active principle of hydrous sulphuric
acid.

The difference between the oxisalts and the halosalts is
very easily illustrated by formulae. In K|FF — fluoride of
potassium, there is but one single line of substitution, that is
to say, that of K|FF, whilst in KOOOOS (sulphate of po-
tash) there are two, K|OOOOS and KO|OOOS of which we
use the first in replacing one metal by another, for instance,
copper by iron ; and the second in replacing one oxide by
another.

I do not know what value you may attach to this develop-

* In the Berzelian symbols, K stands for kalium, or potassium, S for
sulphur, O for oxygen, and O3 for three atoms of oxygen, O4 for four atoms
of oxygen.

f That is to say, if the salt called sulphate of potash, be considered as a
compound of potassium, and a quadroxide of sulphur, instead of being
viewed as a protoxide of potassium, or potash, and tritoxide of sulphur, or
sulphuric acid.

This is the formula for cyanide of potassium, consisting of potassium,
K, and cyanogen, or two atoms carbon and one of nitrogen, C8 N.

182 Dr. Mare and M. Berzelius on certain points

merit of the constitution of the oxysalts (which applies equally
to the sulphosalts and others) : but as to myself, I have a
thorough conviction, that there is therein, something more than
a vague speculation ; since it unfolds to us an internal analogy
in phaenomena, which, agreeably to the perception of our
senses, are externally analogous. If these phaenomena are to be
considered agreeably to the ideas of Mr. De Bondsdorff, how
does it happen that sulphur, phosphorus, arsenic, and other
radicals of the strongest oxacids, when united with chlorine,
bromine, iodine, &c, do not combine with the chlorides *,
bromides, &c, of the metals of the alkalies and of the earths ;
whilst the chloride and bromide of potassium combine easily
with those of magnesium, iron, and manganese ? Should then
the chloride of magnesium, or that of manganese, be a stronger
acid than the chloride of sulphur, or chloride of phosphorus?
How is it consistent with these ideas that we can obtain cry-
stallized salts as well with as without water, of combination,
composed of chloride of calcium and of oxalate, or of acetate
of lime? Should the oxysalt be here the acid, or the base?
I have now displayed to you, the considerations which have
guided me, and which I think are not destitute of foundation.

I cheerfully admit that it would be preferable to employ the
word chlorohydric, instead of hydrochloric. My motive for
retaining this last, is, that I have ventured to propose a new
nomenclature in a language foreign to me, in which it was
inexpedient to make changes, which could be avoided without
inconvenience. I also agree with you, that we ought not to
use combustible and oxidable, as having the same meaning.
I have deserved your strictures for this inconsistency in my
language; but I must suggest as an apology, that the two words
were formerly used as synonymous, and that the work, in
which you have recently noticed this oversight, was first pub-
lished in 1806, having been from time to time remoulded for
new editions, without its having been possible to eradicate all
that has not kept pace with the progress of science.

Accept the assurance of my perfect esteem, and of the senti-
ments of sincere friendship with which I have the honour to
be, Yours, &c.

An Examination, by the Author of this Article, of the Sugges-
tions in the preceding Letter of Berzelius, and how far the
Objections made to his Nomenclature are therein answered.

So far as my strictures were founded on the alleged diffi-

* I have translated chlorure, fluorure, bromure, by chloride, fluoride,
and bromide, agreeably to the practice of the British chemists.

of Chemical Philosophy and Nomenclature. 183

culty of defining the terms acid, salt, and base, in any mode
consistent with nis classification, they are not met by any facts
or reasoning in the much-esteemed letter of my illustrious
correspondent. The impracticability of defining a salt, he
does not deny ; and with great candour he admits that, in his
definition of acidity, he has not been consistent. He concedes
that it would be preferable to give the syllable, indicating the
electro-negative ingredient, the precedence, as nothing but
unwillingness to innovate prevented him from pursuing that
course.

He acknowledges that as combustion, in many instances,
takes place without the presence of oxygen, the application of
the word combustible, should not be confined to bodies which
are susceptible of oxydizement.

My definition of acidity was as follows : —

" When, of two substances capable of combining with each
other so as to form a tertium quid *, and having an ingredient
common to them both, one prefers the positive, the other the ne-
gative pole of the voltaic series, we must deem the former an
acid, and the latter a base. Also all substances having a sour
taste, or which redden litmus, must be deemed acids, agreeably
to usage" This definition I would now amend by leaving out
the last sentence, and substituting therefore, the following:
Also when any substance is capable of forming a tertium quid
with any acid or base agreeably to the preceding definition, it
must be considered as an acid in the one case, a base in the
other. The definition, thus amended, takes in the organic
acids and bases. In the form in which it was at first pro-
posed, it has not been alleged defective by Berzelius; but he
has striven to show an incongruity in the attributes of his
double salts, when contrasted with those resulting from the
union of some of the acids and bases of his amphigen class;
which incongruity is, in his opinion, a sufficient reason for not
considering them as simple salts, and their ingredients as acids
and bases, agreeably to the opinions of De Bondsdorff and
myself.

Berzelius errs in confounding my opinions with those of
De Bondsdorff. However I may have admired the sagacity
with which that chemist investigated the pretensions of some
haloid salts to certain attributes of acidity or alkalinity ; in my
letter on the Berzelian nomenclature, I signified my unwilling-
ness to rest my opinions upon a basis so narrow, as that which

• This term tertium quid has been used by chemists, more formerly than
of late, to designate a compound resulting from the union of two bodies,
but in its properties resembling neither.

184 Dr. Hare on certain points

lie had endeavoured to establish. I stated that I did not
deem it necessary to appeal to his excellent observations,
proving certain attributes of acidity to exist in one case, those
of alkalinity in the other. I alleged my definition to be founded
on the conviction that the property of affecting vegetable co-
lours, on which that sagacious chemist lays so much stress,
has not, latterly, been deemed necessary in acids ; and that
in bases it never was required. As respects them, it only
served as a mean of subdivision between alkaline oxides and
other oxibases.

I am at a loss to discover in what part of my letter there
was any language which could convey the erroneous impres-
sion, that, in defining acids and bases I proposed to overlook
properties, and to be regulated by attention to the number of
atoms in a compound. Certainly nothing was more foreign
to my thoughts.

It is assumed by Berzelius that the saturation of the fluo-
base of potassium by fluohydric acid, cannot be considered as
analogous to the saturation of the oxybase of potassium by
sulphuric acid ; because the resulting compound is to the taste
in one case neutral, in the other sour. In reply I suggested
that if the salidity of the biborates and bicarbonates was not
to be questioned on account of their alkaline taste, nor that
of the protochloride of tin on account of its sourness, it was
not consistent that the pretensions to salidity of the fluohy-
drate of the fluobase of potassium should be denied on account
of its sour taste. I will now add that if the fluosilicate of po-
tassium be a double salt, the fluoride of silicon one of its two
constituents must be a simple salt, and yet it is sour. If a
simple salt may be sour, why may not a double salt have this
attribute; and how in fact can its presence be inconsistent
with salidity? Is not the absence of this characteristic in si-
lica and tannin, and many other acids, as much against their
claims to acidity, as its presence in other compounds is an
objection to their association with saline bodies ? It is consi-
dered by Berzelius an objection to the views which I have
espoused, that the halogen bodies, while forming acids with
various metallic radicals which oxygen does not acidify, do
not form acids with sulphur, phosphorus, and arsenic which
oxygen does acidify ; yet what is there in this, more difficult
to reconcile with the established results of chemical combina-
tions, than in the fact that oxygen forms with sulphur, phos-
phorus, and arsenic, strong acids, with hydrogen water; while
with hydrogen the halogen bodies all form compounds which
Berzelius describes as having the highest pretensions to
acidity ? The highly active acid properties of the fluorides of

of Chemical Philosophy and Nomenclature. 185

boron and silicon, would lead us to expect similar compounds
to be formed by the same radicals, with the other halogen
bodies, contrary to experience. Chemistry makes us ac-
quainted with many similar discordances. How is it that
oxygen forms aeriform compounds with an extremely fixed
body in the instance of carbon ; while in that of phosphorus
or arsenic, both volatilizable, it forms acids which are com-
paratively insusceptible of volatilization? Wherefore does not
hydrogen produce an acid with phosphorus and arsenic, as
well as with sulphur ?

According to Berzelius, all the halogen bodies produce with
hydrogen combinations which are as highly endowed with the
attributes of acidity, as the strongest acids into which oxygen
enters as a constituent. It is conceded in his letter that his
language respecting these combinations cannot be reconciled
with his declaration in one place that they do not combine with
oxybases, and in another that a body which cannot so com-
bine is not an acid. It strikes me, that the only way in which
the admitted inconsistency of his description of these bodies,
with his definition of acidity, can be avoided, is by assuming
that they combine as acids with haloid bases, although de-
composed by oxybases.

I will now proceed to comment on a new subject for con-
sideration, presented in Berzelius' s letter in reply to mine.

It must be evident that every oxysalt, composed of an ox-
acid and an oxybase, must consist of an atom of each radical,
and as many atoms of oxygen as exist both in the acid and in
the base. Thus sulphate of potash consists of an atom of po-
tassium, an atom of sulphur and four atoms of oxygen, and
may be represented either by SOOO KO or SOOOOK.

Berzelius in his letter repeats an ingenious suggestion pre-
viously advanced in his treatise, that SOOOO, (sulphur with
four atoms of oxygen,) may act, as a compound halogen body
like cyanogen, and thus form a salt by union with an atom
of any radical. He conceives that the apparent want of ana-
logy, which induced him to separate into two classes, the am-
phigen and halogen bodies, disappears under this view of the
phaenomena; and that his amphide salts might be considered
as constituted of a compound halogen body and an elementary
radical. But however we may admire the ingenuity of these
suggestions, ere, in obedience to them, we extend the limits
of the halogen class, I would request that the word salt should
be defined, and that it be shown that consistently with any
definition which can be devised, there is any class of bodies
in nature which merit the appellation of salt-producers. Be-
Third Series. Vol. 11. No. 6G. Aug. 1837. 2B

1 86 Dr. Hare on certain points

fore enlarging the superstructure, let it be shown that the
basement has been well grounded.

Berzelius lays some stress on the community of effect, in
the evolution of hydrogen, both by acids formed by hydrogen
with halogen bodies, and by diluted hydrous sulphuric acid,
as evincing a similitude of composition justifying the sugges-
tion above quoted from him. But I conceive that this com-
mon result is better explained by ascribing it to the tendency
of radicals to displace each other from combination, whether
existing in a simple or a complicated compound. If water
exists as a base in hydrous sulphuric acid ; as I have else-
where suggested, we may consider this hydrous acid as a sul-
phate of the oxybase of hydrogen* ; and that when it reacts
with zinc or iron, the proneness of hydrogen to the aeriform
state enables either metal to take its place, agreeably to the
established laws of affinity.

It may be proper, before concluding, to explain more par-
ticularly the nomenclature which I have adopted.

The amphigen and halogen bodies of Berzelius, as they
produce acids and bases according to my definition, are all
classed as basacigen bodies. Of course oxygen, chlorine,
bromine, iodine, fluorine, cyanogen, sulphur, selenium, and
tellurium, are included in this class.

The general designation of a binary compound of a basaci-
gen body, is the termination in ide ; the special, the termina-
tion in acid, when the compound acts as an acid ; in base, when
it acts as a base.

Hence an oxide, may be an oxacid, or an oxybase ;

a chloride, a chloracid, or a chloribase;

a bromide, a bromacid, or a bromibase ;

an iodide, an iodacid, or an iodobase;

a cyanide, a cyanacid, or a cyanobase ;

a sulphide, a sulphacid, or a sulphobase;

a selenide, a selenacid, or a selenibase;

a telluride, a telluracid, or a telluribase.

Compounds which consist of radicals only, are distinguished
by the term wet equivalent to the French ure. Hence car-
buret, phosphuret, boruret, silicuret, 4 c.

Of any two binary compounds containing each the same
basacigen body and forming one compound, the more electro-
negative is an acid, the other a base. Hence all the electro-
negative haloid compounds in the Berzelian double salts, are
acids, and the electro-positive, bases. Where there are two
such compounds, one containing one basacigen atom, the other
two atoms or one and a half, the former has a termination in
• See Lond. and Edinb. Phil. Mag. vol. vi. p. 328.

of Chemical Philosophy and Nomenclature. 187

ous, the latter in ic. As for instance the chlorureplatinoso-
potassique of Berzelius, is a compound of chloro platinous acid,
and the chlorobase of potassium, and is the chloro-platinite
of potassium. The chlorureplatinico-potassique of the same
author, is the chloroplatinate of potassium*.

By analogy the intelligent reader may easily make these
examples a clue to designate any other of the double salts of
Berzelius so as to accord with the plan in question. He may
have a bromoplatinate or bromoplatinite, a iodoplatinate or
iodoplatinite, a fluoplatinate, fyc; or changing the radical a
chloroaurate or chloroaurite, a bromoaurate or bromoaurite, tyc.

The terms amphigen and halogen being employed both
from expediency, and in honour of their author, we may use
his terms haloid and amphide, to distinguish the acids or bases
severally formed by these classes, the abbreviations halo and
amph, being employed in composition. Thus I designate the
acids formed by the halogen bodies with hydrogen, as halo-
hydric acids; those formed with that radical by the amphigen
bodies, as amphydric acids. As the same radical will in
other cases be found to form acids with several of the halogen
bodies, platinum for instance, the acids thus produced may
be called haloplatinic acids; or if gold were the radical, they
would be called haloauric acids. These examples will sug-
gest to the chemical reader a series of names, as for instance
haloargentic, halocupric, halostannic, halopalladic.

I consider prussian blue as a cyanoferrite of the cyanobase
of iron, or briefly a cyanoferrite of iron. The diversity of
properties which enables two cyanides of iron to exist in com-
bination in this cyanoferrite, one as an acid, the other as a
base, is one among many other instances in which compounds
constituted of the same elements in the same ratio, have dif-
ferent properties, and are said in consequence to be isomeric,
or to afford cases of isomerism.

The salt designated by Berzelius as the " cyanure ferroso-
polassiq?ie," is the well-known test for iron heretofore called
ferroprussiate of potassa; under the idea that it consisted of

* In designating salts of the metals proper, as for instance, the nitrate of
mercury; the idea of the oxydizement of the metal is always understood,
although usually not expressed. In the instance above cited, we actually
mean the nitrate of the oxide, or oxybase of mercury. By analogy, I here
use the term chloroplatinate of potassium, for chloroplatinate of the chloro-
base of potassium. It is in fact well known to chemists, that acids do not
unite directly with metals. The only alleged exception to this rule, of
which I have any knowledge, is that of tellurium and sulphuric acid. It is in-
ferred, therefore, that when an acid is combined with a metal, the latter
must exist in the state of a base formed with the basacigen body which
enters into the composition of the acid.

2 B2

188 Dr. Hare on Chemical Nomenclature.

prussic acid, iron, and potassa. As the prussic acid was
viewed at the same time as a compound of hydrogen and cy-
anogen, the ferroprussic acid was considered as a compound
of cyanogen, hydrogen, and iron. According to Berzelius,
the supposed ferroprussiate is a compound of a " protocyanure"
of iron, and a " cyanure of potassium'" each being a simple
haloid salt, and the aggregate a double " cyanure." Agreeably
to my nomenclature, the "protocyanure" of iron is considered
as cyanoferrous acid, and the "cyanure" of potassium as a
cyanobase ; the aggregate being a cyanoferrite of the cyano-
base of potassium, but designated briefly as a cyanoferrite of
potassium.

I infer that the "ferroprussic" acid is analogous in consti-
tution to the triple compound of fluorine, silicon and hydro-
gen, improperly called hydrofluosilicic acid ; and that, consist-
ently with the hypothetical views under which the latter re-
ceived its name, the former should be called hydrocyanoferric
acid. Even admitting the correctness of the hypothetical im-
pression, to which I have alluded, agreeably to which such
compounds are acids with a double radical, I urged that the
appellations of such compounds should be so altered as to
give precedency to the electro-negative ingredient. Hence
the one would be called cyanohydroferricacid ; and the other,
fluohydrosilicic acid. But in my letter to Silliman, already
cited, I advanced a new hypothesis respecting the constitution
of the fluohydrosilicic, and fluohydroboric acids. I suggested
that they should be considered as compounds in which the
fluorides of silicon or boron acted as acids, the fluoride of
hydrogen as a base. Consistently with that doctrine, I would
consider the protocyanide (or " cyanure") of iron in the alleged
ferroprussic acid, as acting as cyanoferrous acid, the cyanide
of hydrogen [prussic acid), as a cyanobase, forming, by their
union, a cyanoferrite of hydrogen.

As compounds, consisting of a basacigen body, hydrogen
and a radical, do not, when presented to bases, enter into
combination ; but are, on the contrary, decomposed so as to
allow another radical to take place of their hydrogen, it is in-
consistent with chemical law, as stated by Berzelius*, or my
definition of acidity, (page 183,) to designate them as acids.

I have called the electro-negative "protocyanure" of iron
of Berzelius, cyanoferrows acid, because there is " sesquicy-
anure" in the " cyanureferrico-potassique" of that author, which,
by analogy with the nomenclature of the oxacids, is entitled
to the appellation of cyanoferric acid.

* TraitCj page 41, vol. ii.

[ 189 ]
XXIII. Proceedings of Learned Societies,

ROYAL SOCIETY.

June 8. — A Paper was in part read, entitled " Observations on
±\- the minute structure of the higher forms of Polypi,
with observations on their classification." By Arthur Farre, M.B.,
Lecturer on Comparative Anatomy at St. Bartholomew's Hospital.
Communicated by Richard Owen, Esq., F.R.S.

June 15 The reading of Dr. A. Farre's paper was resumed and

concluded.

After a short account of the labours of preceding naturalists in
that department of zoology which comprises the various kinds of
polypes, and of the different characters on which they have founded
the classification of these animals, the author proceeds to the state-
ment of his own observations on several species which had not
been previously investigated with sufficient minuteness and care.
Two of the species described he believes to be entirely new, and he
has accordingly given them the names of Boxverbankia densa, and
Lagenella repens. The other species which are the subject of the
author's investigation, are Vesicularia spinosa, Valkeria cuscuta,
Alcyonidium diapkanum, Membranipora pilosa, and Notania lori-
culata.

He then discusses the principles on which the classification of
this tribe of zoophytes should be founded, and proposes on these
principles to give the name of Ciliobrachiata to the whole group of
polypes characterized by the possession of ciliated tentacula, and a
free alimentary canal with two orifices : this group again he divides
into two subordinate groups, namely, the Hydriform and the Acti-
?tiform, or Zoanthiform polypes. Under the title of Nudibrachiata
he proposes to comprehend all those polypes which partake of the
nature of the hydra, and whose tentacula are unprovided with cilia,
corresponding to the Anthozoa of Ehrenberg.

"On the Temperature of Insects, and its connexion with the
functions of Respiration and Circulation." By George Newport,
Esq. Communicated by P. M. Roget, M.D., F.R.S.

The author states at the commencement of his paper, that, al-
though it has been long known that insects living in society, as the
bee and the ant, maintain in their habitations a temperature higher
than that of the open air, the fact had never yet been established
that individual insects of every kind possess a more elevated tem-
perature than that of the medium in which they reside, and that in
each species the degree of elevation varies in the different stages of
their existence. He was first led to study the temperature of in-
sects in consequence of the curious results which he had met with
in some observations he had himself made, in the autumn of the
year 1832, on a species of wild bee in its natural haunts, with a view
to ascertain, as had been suggested to him by Dr. Marshall Hall,
the relation between the temperature of these insects during their
hybernation, and the irritability of their muscular fibre : but the
fact of the existence of a higher temperature in individual insects

1 90 Royal Society.

had been ascertained by himself prior to these observations ; the
results of which observations, together with other facts connected
with the physiology of insects, he subsequently communicated to
Dr. M. Hall.

Since the time when the author has been engaged in the prose-
cution of this inquiry, some observations on the same subject have
been published by Dr. Berthold, of Gottingen, who expresses it as
his opinion that insects ought not to be regarded as cold-blooded
animals, but who does not appear to have detected the existence
of a temperature higher than the surrounding medium in any indi-
vidual insect. The author also notices the observations on this subject
made by Hansmann, Juch, Rengger, Dr. John Davy, and others,
some of whom have detected, while others have not observed, the
existence of an increased temperature in this class of animals. He
then gives a detailed account of the precautions to be taken for
ensuring accuracy in making observations of this kind -, and remarks
that greater reliance is to be placed on those made on the external
than on the internal temperature of the animal, seeing that compa-
rative results are all that can be obtained, and that the injury inflicted
on the insect by its mutilation very materially interferes with the
correctness of the conclusions as to the degree of internal tem-
perature.

After premising these introductory remarks, the author gives a
detailed account of his observations on the temperature of insects
in their several states of larva, pupa, and imago, from which it ap-
pears that those which possess the highest temperature are always
volant insects, and are chiefly diurnal species, residing almost con-
stantly in the open air. He shows that the larva has a lower tem-
perature than the imago, and that the energy of its respiration is also
less, regard being had to the activity of the insect, and to the size of
its body. In lepidopterous insects the average elevation of tempera-
ture above that of its surrounding medium, is in the larva from 0o,9
to 1°5 ; while in the imago it is from 5° to 10°. Among the hymeno-
ptera it is from 2° to 4° in the larva, and in the imago from 4° to 15°
or even 20° j but in all cases the amount of this elevation is shown
to depend on the degree of activity, and the quantity of air respired
during a given period. The author then inquires into the influence
of various circumstances, such as inactivity, sleep, hybernation, and
inordinate excitement, on the temperature of insects; and shows that
the evolution of heat gradually diminishes in a degree corresponding
to the length of time during which the insect remains in a state of
repose, but that it is immediately increased as soon as the insect is
roused into action. He adverts also to the remote cause of hyberna-
tion, which he ascribes, in every state of the insect, to accumu-
lations of adipose matter, or of nutrient fluid, which, being stored
up in the system, induce a plethoric state, from which the animal is
aroused when this store of materials has been exhausted. A variety
of experiments are related, tending to prove that a large proportion
of the heat evolved by an insect, when in a state of great activity,
is dissipated into the surrounding medium, and that the quantity of

Mr. Newport on the Temperature of Insects. 191

heat so generated bears definite relations to the habits, the locality,
and the energy of respiration in each respective species of insect.
Volant insects, he finds, have the highest temperature; and of these
the diurnal bear a higher temperature than the crepuscular; next
to these must be placed the diurnal terrestrial, and last of all the
nocturnal terrestrial species.

In the next division of this paper the author considers the tem-
perature of those insects which live in societies ; and in particular of
the humble bee and the hive-bee. His observations are confirmatory
of many of those of Huber relating to the incubating habits of the
former of these species ; and he has farther ascertained that during
the act of incubation the bees possess a voluntary power of genera-
ting heat, whereby the temperature of their bodies is raised, appa-
rently for the purpose of imparting warmth to the young in the
cells; that this process is accompanied by accelerated respiration;
and that the amount of heat evolved is proportional to the quantity of
air respired. The law established by Dr. Edwards in the case of
the young of mammiferous animals, namely, that they possess less
power of generating heat, and that for a certain time they are unable
to maintain their usual temperature, is shown by the author to be
equally applicable to the early stage of insect life, and also to the
perfect insect immediately after its development from the pupa.

The temperature of the hive-bee is next examined, and it is shown,
contrary to the statements of Reaumur, Huber, and others, that bees
do not maintain a very high temperature in their hives during winter,
but that they are disposed, when not disturbed by any occasional
vicissitudes of atmospheric temperature, to assume the state of hy-
bernation ; although, on the other hand, when the bees are much dis-
turbed, the temperature of the hive may, even in the midst of winter,
become greatly raised. The temperature of the hive is lowest in
January, and gradually increases up to the period of swarming, in
May or June, after which time it diminishes. A table is given ex-
hibiting the results of successive observations on the influence
of the diminution of heat and of light which attended the progress
of the annular eclipse of the sun on the 15th of May, 1836, on the
temperature of the hive.

It appears from the inquiries of the author that different parts of
the hive do not preserve the same relative heat among one another
at different periods, and also that the amount of free heat in the hive
is often 10° or 15°, even in the months of July and August.

The remaining division of the paper is devoted to the considera-
tion of the connexion existing between the development of heat
and the functions of respiration, circulation, and digestion. The
state of the pulse during all the different stages of the larva until
its metamorphosis into the pupa is examined with great minuteness,
and the results are given in a tabular form. The author traces the
rate of pulsation during different conditions of repose and activity,
and the corresponding frequency of respirations, and finds that al-
though there is a general accordance between the activity of these
two functions, yet that the activity of respiration and the quantity

192 Royal Society.

of heat evolved do not depend primarily on the velocity of the cir*
culation, but that under all circumstances the quantity of heat de-
veloped is exactly proportional to the quantity of respiration. While
the insect is feeding, and digestion is going on, the evolution of
heat increases, and while it is fasting it diminishes; but this dimi-
nution has a limit, whereas increased respiration is invariably attended
by increased heat. Gaseous matter is exhaled in great abundance
from the surface of the body of an insect, and contributes to regulate
and equalize its temperature; but the quantity diminishes in propor-
tion to the length of time during which it has been deprived of food.
The author maintains that animal heat is not an effect of mere
nervous influence, either general or ganglionic ; an opinion which he
derives from the following considerations : first, that in many insects
in which considerable degrees of heat are evolved, and the respira-
tion is energetic, the nervous system is small compared with that of
others in which the respiration is less vigorous ; and secondly, that if the
evolution of animal heat were dependent on the existence of ganglia,
the leech ought to generate more heat than the larva of the Lepi-
doptera, since it has a much greater number of ganglia. Hence he
is disposed to draw the general conclusion that animal heat results
directly from the changes which take place during respiration ; and
that the reason why so large a quantity passes oft' so rapidly from
the body of an insect is because it does not become latent, since the
circulating fluid, unlike what takes place in the higher animals, is
neither completely venous nor completely arterial, but of a character
intermediate between both.

Twenty-one tables are annexed exhibiting the records of the experi-
ments referred to in the paper on the respiration, temperature, and
circulation of insects.

" Observations on the Dry-rot of Ships, and an effectual method
to prevent it pointed out." By James Mease, M.D. Communi-
cated by Charles Kcenig, Esq., For. Sec. R.S.

The method recommended by the author for preventing the oc-
currence of the dry-rot in ships is to impregnate the timbers and
planks with common salt, as is practised by the ship-builders in
Philadelphia. For this purpose all the spaces between the timbers
and the outside and inside planks are to be filled with Spanish or
Portugal salt, driven down as the filling proceeds. The salt is found
to penetrate thoroughly, and completely to saturate the wood, com-
bining with its native sap and preventing fermentation and the con-
sequent evolution of foul air. The principal inconvenience attend-
ing this method is the dampness of the ships ; an evil for which the
author suggests various remedies.

"Experimental Researches on the conducting powers of wires for
Electricity j and on the heat developed in metallic and liquid con-
ductors." By the Rev. William Ritchie, L.L.D., Professor of Na-
tural Philosophy in the Royal Institution of Great Britain, and of
Natural Philosophy and Astronomy in University College, London.

In a former communication, published in the Philosophical Trans-
actions for 1833, the author endeavoured to show that the quantity

Royal Society. 193

of voltaic electricity conducted, or the force of the current, was a
function of a greater number of variables than had been previously
supposed. As the theory which he proposed for estimating the con-
ducting powers of substances has been controverted by M.Lenz*,he
has been induced to reconsider the subject, and finds reason to be
satisfied with the correctness of his former views. He farther finds
that with feeble magnetic needles the deflecting forces are not pro-
portional to the force of the current, but approach nearer and nearer
to that proportion by increasing the magnetic power of the needles ;
a result which the author thinks is strictly deducible from the uni-
versal law of nature, that the attraction mutually exerted by two
bodies is measured by the sum of their masses. He shows that the
formula of Ohm, expressive of the conducting powers of wires, and
of the resistances which they offer to currents of voltaic electricity,
is an approximation to the truth only in the case of feeble currents,
and that with the same metal, the conducting powers are not as the
lengths of the wires.

The author next inquires into the relation between the heat de-
veloped, which he finds to be, in the same wire, as the square of the
intensity of the current ; and in wires of the same diameter, and
conducting equal quantities of electricity, it is inversely as the con-
ducting power, or directly as the resistance which they oppose to
the current. The facts he has adduced in this paper seem to be at
variance with the generally received theory of caloric, and to be in
perfect accordance with the undulatory theory.

He concludes by describing an experiment confirming the views
he has elsewhere advanced with regard to the difference between the
physical, the physiological, and the chemical effects resulting from
the employment of coils formed of wires of different lengths, being
dependent on the time required by the conductor for returning to
its natural state.

" On the Ipoh or Upas poison used by the Jacoons and other
aboriginal tribes of the Malayan Peninsula." By Lieut. T. S. New-
bold, Aide-de-Camp to Brigadier- General Wilson, C.B. Communi-
cated by P. M. Roget, M.D., Sec. R.S.

The author gives an account of the process by which the Jacoons,
an aboriginal tribe inhabiting the mountains and forests of the Ma-
layan Peninsula, prepare the poison applied to the points of the
slender arrows which are propelled from the Simpitan or blow-pipe.
Three preparations are employed for this purpose, distinguished by
the names of Krohi, Tennik or Kennik, and Mallaye ; the last of
these is more powerful than the other two, and is obtained from the
roots of the Tuba, the Perachi, the Kopah, and the Chey, and from that
of the shrub Mallaye, whence it derives its name. The Krohi poison
is prepared from the root and bark of the Spoh tree, and the roots
of the Tuba and Kopah, with the addition of red arsenic and the
juice of limes ; and the Tennik from the same ingredients, omitting
the Kopah root. A i'ew experiments are related, made by the au-
thor with a view to ascertain the effects of the poisoned arrows on
* See Scientific Memoirs, vol.i. p. 311.

Third Series. Vol. 11. No. 66. Aug. 1837. 2 C

194 Royal Society.

living animals, from which it appears that the train of symptoms
commences in a tew minutes after the infliction of the wound, and
terminates fatally with more or less rapidity, according to the size
of the animal.

" Delia Velocity del Vento. Memoria diretta alia Regali Societa
di Londra per essere inscritta nelle Transazioni Filosofiche, et per
concorso del premio annuale di fisica : di Luigi Dau, Dottore in
Matematica e Fisica." Communicated by Charles Kcenig, Esq. For.
Sec. R.S.

The author endeavours to investigate the relation which he be-
lieves exists between the velocity of the wind and the oscillations
of the barometer, and thence to derive rules for calculating the
former from observations of the latter.

" Considerations physiques sur le passage Nord-ouest ;" by the same.
Communicated by the Right Hon. the Earl of Minto, G.C'.B. F.R.S.

The author of this memoir, considering that the practicability of
a North-west Arctic passage must depend on the mean summer at-
mospheric temperature of the most northern point of the continent of
America being above that at which the congelation of sea water takes
place, applies himself to the determination of these temperatures.
The results of his calculations are given in a table, exhibiting the
extreme and the mean temperatures of the atmosphere for each of the
summer months, from May to September, at all degrees of latitude,
from 60° to 80° inclusive. According to this table, the temperature
of zero, which is about the freezing point of sea water, prevails, at
60° of latitude, on the 10th of May ; at 61° lat. on the 20th of Mav;
at 63°, on the 1 st of June ; at 65°, on the 10th of June ; at 67°, on the
20th of June; and at 71°, during the whole of the months of July
and August. The author concludes that navigators can reach, with-
out danger of being obstructed by ice, the latitude of 71° during these
latter months : and that since the American continent does not pro-
bably extend beyond 70° north latitude a passage to the North-west
is then open. He recommends, however, that instead of attempting
it by the dangerous navigation of the polar sea, a coasting voyage
between the continent and the numerous islands which exist in that
ocean should be undertaken ; or, what he thinks still more pro-
mising of success, an expedition by land for exploring the country
intervening between the Coppermine River and Hudson's Bay.

" Causes de la Variation diurne de 1' Aiguille aimantee, de la Lumiere
zodiacale, des Aurores Boreales, et M§thodesimplifiee pour le releve-
ment desLongitudes, Memoire soumisa la Societe Royale de Londres,
pour le concours du prix d'Astronomie. Par Demonville."

The author's speculations proceed on the hypothesis he has adopt-
ed, that the Sun, Moon, Jupiter and Mars perform a diurnal and
perfectly circular revolution round the earth.

"On the elementary structure of the Muscular Fibre of Animal and
Organic Life j" by Frederic C. Skey, Esq , Assistant Surgeon to St.
Bartholomew's Hospital, F.R.S.

The author having withdrawn the paper bearing the same title
which he had formerly communicated, and which was read to the

Dr. Dalton on the Constitution of the Atmosphere. 195

Society on the 9th and 16th of February last* ; and having made
in it several alterations and additions, consisting chiefly in notices
of the discoveries of preceding anatomists in the same field of in-
quiry, again presents it to the Society, with these improvements.

f Sequel to an Essay on the Constitution of the Atmosphere
published in the Philosophical Transactions for 1826 f j with some ac-
count of the Sulphuretsof Lime;" by John Dalton, D.C.L., F.R.S.

The author communicates in this paper an account of the inves-
tigations on the constitution of the atmosphere, which have engaged
his attention during a long period of years. He enters into an ex-
amination of the comparative advantages of the three methods which
are most in use for analysing common air, namely, firing it with hy-
drogen in Volta's eudiometer, or abstracting the oxygen by means
of nitrous gas and quadrisulphuret of lime ; and details the pre-
cautions to be taken in the employment of each of these methods,
and the degree of accuracy to be expected from the results under dif-
ferent circumstances. He then relates numerous experiments made
on air obtained from great heights, from which he is led to the con-
clusion that the proportion of oxygen to azote in the atmosphere on
the surface of the earth is not precisely the same at all places and
times ; and that in elevated regions this proportion is somewhat less
than at the surface of the earth, but not nearly so much as the
theory of mixed gases would require, and that the reason for this is
to be found in the incessant agitation of the atmosphere produced
by winds and other causes.

" Researches on the Tides. Eighth Series. On the progress of the
Diurnal-Inequality-wave along the coasts of Europe." By the Rev.
William Whewell, F.R.S. , &c.

In the seventh series of these researches J, the author pointed out
the laws which the diurnal inequality of the height of high water
follows, and showed that those laws are modified so as to exhibit very
remarkable differences at different places, and to occasion some
difficulty in conceiving the mechanical propagation of the tide-wave.
He then suggested what appeared to be a possible solution of the
difficulty j but as this suggestion was founded on facts from a few
places only, he resolved to attempt to trace the progress of the
wave which brings the diurnal inequality on some of the coasts, on
which simultaneous observations were made at his request in June
1835; and the present memoir contains an account of the conclu-
sions to which he has been led by this investigation. The details
which he gives of the observations made, with this view, at nineteen
different stations, appear to establish the conclusion, that the differ-
ences of diurnal inequalities at different places are governed by local
circumstances, and do not form a progressive series.

" Note on the Fluctuations of the Height of High-water due to
changes in the Atmospheric Pressure." By J. W. Lubbock, Esq.,
F.R.S.

* See our last volume, p. 377.

f An abstract "of Dr. Dalton's Essay on the Constitution of the Atmo-
sphere will be found in Phil. Mag. First Series, vol. Ixviii. p. 310.

X See our last volume, p. 380.

2C2

1 96 Zoological Society.

The author verified, both at Liverpool and at London, the exist-
ence of a fact similar to that which M. Daussy had ascertained at
Brest, namely, the rise of the ocean when the barometer is depressed ;
and remarks that the correction due to changes in the atmospheric
pressure is by no means inconsiderable. He suggests the question
whether the surface of the ocean rises in narrow seas simultaneously
with the depression of the barometer, or otherwise. With a view to
the solution of this question, he gives a tabular diagram showing the
correspondence between the calculated and the observed heights, in
their relation to the heights of the barometer at Liverpool and at
London, from which it would appear that the effect of changes in the
atmospheric pressure on the tide is immediate.

" On an improved mode of constructing Magnets," By James
Cunningham, Esq., Member of the Cork Scientific and Literary So-
ciety. Communicated by North Ludlow Beamish, Esq,, F.R.S.,
President of that Society.

The material recommended by the author for the most economical,
as well as effectual method of constructing magnets, is cast iron,
which should be formed in small castings in the form of a horse-shoe,
each weighing about seven ounces ; these he finds, on being touched
in the usual manner by a small compound magnet, received and re-
tained the impregnation better than any which he had previously
constructed of steel.

The Society then adjourned over the long vacation, to meet again
on the 16th of November next.

ZOOLOGICAL SOCIETY.

December 13, 1836. — Part of a paper by M. Frederick Cuvier was
read, on the Family of the Dipodidcc, including the Jerboas and Ger-
billas*.

Notes on the anatomy of the Spermaceti Whale, (JPhyseter ma-
crocephalus, Auctorum,) principally relating to its dentition, and to
the structure and appearances presented by the soft parts, by Mr.
F. Debell Bennett, Corresponding Member of the Society, were
then read.

Mr. Bennett remarks that a greater disproportion exists between
the sexes in this species of Whale than is observed in any other
cetaceous animal ; for while the usual length of the largest male
Cachalots, taken in the South Seas, is about 60 feet, that of full-
grown females is only 28, and rarely, if ever, exceeding 35.

When the young male Cachalot has attained the length of 34 feet,
its teeth are perfectly formed, though not visible until it exceeds 28.
The upper jaw usually described as toothless, has on either side a
short row of teeth, sometimes occupying the bottom of the cavities
which receive the teeth of the lower-jaw, but generally corresponding
to the intervals between them. The entire length of these teeth is
about three inches ; they are slightly curved backwards, and elevated

* The abstract of this and the concluding part of the Memoir will be
found in the Proceedings for December 27, 1836.

Zoological Society. 197

about half an inch above the soft parts, in which they are deeply
imbedded, having only a slight attachment to the maxillary bone.
Their number is not readily ascertained, because the whole series are
not always apparent ; but in two instances Mr. Bennett found 8 on
each side. These teeth exist in adult Whales of both sexes, and
though not visible externally in the young Cachalots, may be seen
upon the removal of the soft parts from the interior of the jaw.

" The eye of the Cachalot is small, and placed far back on the head,
above and between the pectoral fin and angle of the lower jaw. Its
situation is chiefly marked by a raised portion of integument around
it. The aperture for vision does not exceed 2 inches in the longitu-
dinal, and 1 inch in the vertical direction. The eyelids are without
cilia and tarsal cartilages ; they are composed of two horizontal bands
of integument, each, in the example from which I describe (viz. a half-
grown male), two inches in depth, and connected with each other at
the inner and outer canthus. Between each of the eyelids and the
blubber exists a distinct line of separation, marked by a somewhat
deep groove, having a duplicature of thin membrane, serving as a
surface or hinge on which the lids move. At these lines of demar-
cation all integument partaking of the nature of fat ceases, and the
texture of the tarsi thus insulated is composed solely of common
skin and cellular and other membranes, together with a dense layer
of muscular fibres deposited in its centre. The conjunctiva of the lids
is highly vascular, injected with blood, and covered with orifices of
mucous ducts. At the inner canthus of the eye it forms a thick
duplicature, of crescentic form, constituting a rudimental third eye-
lid, not unlike the haw of the horse. The globe of the eye is chiefly
lodged in the soft parts, but little if any of its substance entering
the bony orbit. It is deeply set within the lids, and does not in size
much exceed that of an ox. Its size in an adult female was 21 inches
in the longitudinal, and the same in the vertical direction. The in-
terior or cavity was 1^ inch in each of the last-named directions, and
its depth frds of an inch only.

" The globe at its greatest circumference was 7£ inches : the trans-
parent cornea at its transverse or broadest diameter measured 1 inch,
and in its vertical or narrowest Jths of an inch. The muscles of the
globe formed a dense mass surrounding the sheath of the optic nerve,
and were inserted in one continuous line over the circumference of
the globe at its greatest convexity.

" The optic nerve before penetrating the sclerotic is continued to
some length. It does not exceed the circumference of a crow's quill,
but is surrounded by a dense fibrous sheath nearly 4 inches in peri-
meter, and which, where the nerve perforates the globe, terminates
on the posterior surface of the latter. Around the globe and its
muscles much cellular tissue and true fat are deposited. The eyeball
in shape is riot a perfect sphere ; its anterior and posterior surfaces
are flattened : that portion of the conjunctiva of the globe immediately
surrounding the cornea, and the only portion exposed between the
aperture of the lids, is of an intense black hue. It is possible this
dark portion may be a membrane distinct from the conjunctiva, since
around the extent it occupies, it terminates by an irregular margin,

1 98 Zoological Society.

and is capable of being detached from the conjunctiva, when it presents
the form of a delicate layer of cuticle, with a black pigment deposited
beneath its surface*.

" The cornea of the Cachalot is dense, and composed of many
layers ; when divided, a small quantity of limpid aqueous humour
flows forth : the anterior chamber of the eye is very limited, and the
crystalline lens projects into it through the pupillary aperture. The
iris is a coarse membrane of a dull-brown colour, with a narrow zone
of lighter hue surrounding its outer margin. Its inner and free margin
is very thin, and embraces the protruding convexity of the lens.

"The lens is small, certainly not exceeding in size that of the human
eye : it forms nearly a perfect sphere : the vitreous humour tolerably
abundant. The retina was spread with beautifully delicate arbo-
rescent vessels, and afforded a small bright spot at the insertion of
the optic nerve. Beneath the retina was spread a tapetum of dense
membranous texture, and yellow-green or erugo-green colour. The
sclerotic at its posterior third is thick, fibrous, and resisting, whilst
its anterior third is thin and flexible; no lachrymal apparatus
exists."

In the description of the organs of generation, the cavity in the
head containing the spermaceti, and some more of the soft parts,
Mr. Bennett's observations coincide with those of Hunter and other
comparative anatomists.

A fcetus apparently of mature growth, taken from the abdomen of
a Sperm Whale, measured 14 feet in length and 6 in girth; its
position in the uterus was that of a bent bow.

Mr. Reid brought before the notice of the Meeting a new species
of the genus Perameles, and read a paper giving some account of its
habits, and pointing out its distinguishing characters.

The author states that he was indebted to William Holmes, Esq.,
of Lyon's Inn, for the opportunity of exhibiting this specimen, which
was brought from Van Diemen's Land, where these animals are said
to be common. The same species is also found in Western Australia,
and is there called by the natives Dalgheit, and by the colonists the
Rabbit, under which name it is mentioned by Cunningham in his
work on New South Wales. Widdowson, in his account of Van
Diemen's Land, notices it ; but neither of these writers has given
any description of the animal. From its resemblance to the Rabbit,
Mr. Reid proposes for it the specific name of Lagotis.

Perameles Lagotis. Per. griseus, capite, nuchd, et dorso, castaneo
lavatis ; buccis, lateribus colli, scapulis, lateribus, femoribus extus,
cauddque ad basin, pallide castaneis ; mento, guld, pectore, abdo-
mine, extremitatibus intus anticeque, antibrachiis postice, pedi-
busque suprh albidis ; antibrachiis externe pallide griseis, femo-
ribus extus posticeque saturate plumbeis ; caudd, pilis longis albes-
centibus ad partem basalem, indutd, dein pilis nigris tectd, parte
apicali albd, pilis longis supra ornatd. Vellere longo molli.
Caudd pilis rudis vestitd ; pilis ad pedes brevissimis. Labio su-
periore, buccisque, mystacibus longis sparsis. Auriculis longis,

* A slight dark tint around the cornea is not uncommon amongst the
dark-skinned natives of warm countries.

Zoological Society, 1 99

ovatis, intus nudis, extus pilis brevissimis brunneis, ad marginem,
albescenlibus indutis, pilis ad bases eos plumbeis, apicibus albis
aut castaneis, illis in abdomine omninb albis. Marsupio ventrali
magna, mammis novem, in faciem posticam ; quarum una centra-
lis est, reliquis circumdata, intervallis aqualibus, gyrumque faci-
entibus, transversim unciam cum quadrante reddentem.

poll. lin.
Long, capitis 5 3

corporis 13 0

caudae 10 0

auriculae 3 10

antibrachii t . . . . 4 0

pedis antici 1 8

tibiae 3 9

pedis postici 4 6

ab auriculae basi usque ad oculum . . 2 0

ab oculo usque ad nasum 2 8

Latitudo auriculae 1 9

Hub. In Australia Occidentali et in Terra Van Diemen.
"The ears are long, broad, and ovate, having several semitransparent
dots scattered over their surface (the remains of sebaceous glands).
On the anterior extremity the nails are much elongated ; the second
and third are about ^th of an inch longer than the first ; they are
all flattened at the tips, thus furnishing the animal with a very
efficient apparatus for burrowing. The tail offers many differences
from that of the other species of the genus Perameles. The basal
fourth is clothed with hairs about the same length and colour as those
of the body. The middle half is black, the hairs on the upper part
being elongated ; the remaining part is white, with a ridge of long
white stiff hairs forming a crest.

" The pouch in this specimen (a female) is large, and has 9 nipples
on its posterior surface ; one being placed in the centre, and the
remainder at equal distances form a circle, the diameter of which is
1 inch 3 lines.

" The skull is perfect, but the state of the skin was such as totally
to prevent its removal, and the description is therefore defective in
particulars concerning the bones of the face. The interparietal and
occipital crests are clearly defined and large. The bulla of the ear
is large, and its shape that of a flattened ovoid. The tympanum was
entire, and on removing it the manubrium of the malleus was found
to be twice the length of its body. The zygomatic arch is imperfect
for about the space of \ an inch. The lower-jaw is slender, with a
salient process at its angle. Dent.: Prim. -J-, Can. j^, Mol. spur,
g, Mol. ver. £J. = 48.

" The two front superior incisors are nearly a line apart, small, and
quadrangular ; a small space intervenes between these and the three
succeeding, which are larger, and placed in a continuous series. The
fourth and fifth incisors are about the same distance from each other
as the two anterior. Posterior to the incisors is a space about 5 lines

200 Zoological Society.

in width, for the reception of the inferior canines. The canines are
well developed : another space intervenes between them and the false
molars, which latter are all rather widely separated, of a conical
shape, and have a small tubercle anterior to the body of the tooth.

" The molars oiPerameles, as figured by M. F. Cuvier in his 'Dents
des Mammiferes* consist of two prisms fixed to a slightly curved
base, with the concavity towards the inside of the jaw; but in
this species the molars are quadrangular, having had but two sets
of tubercles, and in the present specimen these teeth are worn
down and present a square surface, inclosed by enamel, having a
band of the same running transversely across the middle of the tooth.
The two last molars of the upper jaw approximate so closely, as to
require careful examination to detect the line of separation. The
teeth of the lower jaw, except in number and in the circumstance of
all the incisors forming a continuous series, do not differ from those
of the upper. When the jaws are closed, the posterior molars of the
upper and lower jaws are in contact.

"A friend of Mr. Gould's, residing in Western Australia, states that
these animals are found beyond the mountains of Swan River, in
the district of York. They feed upon large maggots and the roots
of trees, and do considerable damage to the maize and potato crops
by burrowing. A specimen kept by him in confinement became in
a few days very docile, but was irritable, an i resented the slightest
affront or ill usage. It took bread, which it held in its fore-paws.
A young one to which it gave birth unfortunately escaped, after
being carried in the mother's pouch for several days."

Mr. Reid considers the distinctions between this and the rest of
the species belonging to the genus Perameles so marked, that should
more of the same form be discovered, the above characters would
constitute a subgenus to which the name of Macrotis might be
applied.

Mr. Waterhouse exhibited a second specimen of Myrmecobius,
and directed the attention of the Meeting to certain differences ex-
isting between it and the one upon which he had founded the cha-
racters of the genus, and described under the specific name of 'fas-
ciatus*.'

The present animal differs from the one previously described in
having the black and fulvous colouring of the back less decided,
owing to a larger proportion of interspersed white hairs. The fasciae,
instead of being white, are of a yellowish cream-colour, and they also
differ in number and arrangement. Commencing from the tail, the
three first are distinct and uninterrupted, the intermediate spaces
being about \ an inch in width, black, with white hairs interspersed,
and a few of an ochraceous colour. The fourth is also distinct, but
instead of being continued across the back, it is met by two fasciae
from the opposite side. The two following are continuous, but less
distinct than either of the foregoing. Beyond these, the fasciae are

♦ Mr. Waterhouse's former description of this genus will be found in
Lond. and Edinb. Phil. Mag., vol. ix. p. 520.

Geological Society. 201

almost obsolete, there being only faint indications of them on the
sides of the body.

The most important distinction, however, exists in the teeth, the
present specimen possessing altogether' four more molars than the
one brought before the notice of the Society on a previous occasion.
The entire number of teeth is 52, (26 in each jaw), and the 5 posterior
molars are placed closely together, differing in that respect from
those of the previously examined specimen.

The animal was brought from Van Diemen's Land, and others
similar to it were observed scratching at the roots of trees, and
feeding upon the insects which are generally abundant in such situ-
ations. Their favourite haunts are stated to be the localities in
which the Port Jackson willow is most plentiful.

Mr. Waterhouse remarked that although the differences between
the two animals were considerable, yet he did not consider the di-
stinctions such as to justify his characterizing the one then before
the Meeting as a second species.

GEOLOGICAL SOCIETY.

March 22. — A paper " On the Ancient State of the North American
Continent;" by Thomas Roy, Esq., Civil Engineer, Toronto, Upper
Canada, and communicated by Charles Lyell, Esq., F.G.S., was read
in part.

April 5. — The reading of Mr. Roy's paper was concluded.

The author having in the course of his professional duties, disco-
vered in the lake district of Upper Canada terraces or level ridges
which agreed in elevation at considerable horizontal distances, he
was induced to extend his inquiries and to ascertain how far similar
phaenomena have been observed in other parts of North America, —
what may have been the probable extent of the lake or sea by which
the ridges were formed, — and by what operations the waters were
drained off, leaving only the present detached Canadian lakes.

With a view to ascertain the probable extent of the sea, Mr. Roy
traced upwards from Lake Ontario the successive ridges or terraces*,
and ascertained that their greatest height was 762 feet above the
lake, or 996 feet above the ocean j he therefore assumed, that the
boundary of the ancient sea must have had an elevation of at least
1000 feet, and in consequence, that it must have been formed on the
west by the rocks and mountains ranging from the table-land of
Mexico to the parallel of 47° of latitude j on the north by the barrier
which separates the head-waters of the lakes from those of the Arctic
rivers, and extending to CapeTourmente below Quebec ; on the east
by the hills stretching through the United States to the GuU of
Mexico ; and on the south by a mountain ridge which has been de-
stroyed. The area thus circumscribed is calculated to be 960,000
square miles.

The chief geological feature connected with Mr. Roy's observations

* These parallel ridges were exhibited on a section extending obliquely
from the mouth of the Niagara to the south of Lake Ontario, and over the
ridge north of that lake, to Lake Simcoe.

Third Series. Vol. 1 1. No. 66. Aug. 1837. 2 D

202 Geological Society,

and described in the paper, is the high land which separates Lake
Ontario from Lake Simcoe. The distance between these bodies of
water is 42 miles, and the greatest elevation of the ridge is 762 feet
above Lake Ontario, or 282 above lake Simcoe. The lowest visible
formation is a stratified blue clay which effervesces freely and is of un-
known depth. Above this are immense masses of clay, sometimes re-
sembling fuller's earth, and sand most irregularly associated. The cen-
tral and northern divisions of the ridge are thickly strewed, even to the
highest peaks, with a great variety of boulders, many of them of
immense size, and for the greater part derived from primary or trans-
ition formations. Many of them are rounded, and others decayed by
weathering, whilst the edges of some are perfectly entire. On the
southern side of the ridge boulders are not so common.

The manner in which the materials composing this ridge are ar-
ranged, resembles, in Mr. Roy's opinion, that in which drifted matter
is now disposed along the margin of the lakes at the breaking up
of the ice ; and hence he conceives, that the ridges may, to a consider-
able extent, have been accumulated in a similar manner.

The author then enters into a calculation of the quantity of water
hourly discharged by the Saint Lawrence, the Mississippi and the
Hudson, amounting, according to his estimate, to 4000 millions of
cubic feet ; and afterwards proceeds to show, that in order to reduce
the ancient lake 30 feet, the distance between two of the highest pa-
rallel ridges, fifteen years would be required, supposing the discharge
to be double that at present.

Mr. Roy next details with considerable minuteness, the processes
by which he supposes this vast sea was drained ; but as his descrip-
tions cannot be successfully followed without the aid of diagrams,
they do not admit of being given in the Society's Proceedings.

A paper u On the Geology of the neighbourhood of Smyrna ■" by
Hugh Edwin Strickland, Esq., F.G.S., was then read.

The district described consists of two ranges of high land, running
from east to west, separated by the bay of Smyrna and the alluvial
plain of Bournabat, at the eastern termination of which is a trans-
verse ridge uniting the two ranges.

The rocks belong to the formations described by the author in his
former paper on Asia Minor (Proceedings of Geological Society,
vol. II, p. 424, &c. or L. & E. Phil. Mag., vol. x. p. 68), and are :
1 . Hippurite limestone and schist ; 2. Tertiary limestone and marl j
& Trachytic rocks.

The author supposes that mountains of hippurite limestone formed
the boundaries of a lake in which tertiary beds were deposited, which
were afterwards broken up by the eruption of trachytic rocks, and
that the same event may have produced the drainage of the lake sub-
sequently carried on by the denudation of its outlet, which is now
traversed by the Meles.

1. The hippurite limestone on the south side of Smyrna bay is ac-
companied by much black, greenish, or cream-coloured sandstone,
analogous to the macigno of Italy ; but it is difficult to decide whe-
ther the schist or limestone is highest in geological position. The

Geological Society. 203

latter extends from 1 5 to 20 miles to the east along the north side
of the Tmolus range ; but in Mount Corax the limestone is com-
monly absent, and schistose rocks prevail, in some places yellowish
and friable, in others dark-coloured and compact ; a fine-grained
quartzose conglomerate also occurs.

2. The tertiary lacustrine limestone on the south side of the bay
forms a table-land extending south from Smyrna about 15 miles. It
consists of whitish limestone in horizontal beds containing nodules
and layers of quartz resinite. Planorbes and paludinae abound at cer-
tain points, but are not generally diffused. Greenish marls alternate
with the limestone, and prevail in the central parts of the area where
they contain beds of rolled gravel of nummulitic limestone, schist,
and red trachyte. Conglomerate beds also prevail around the margin.

3. A vast mass of trachyte appears near Smyrna, and from thence
to spread over the lacustrine beds. It consists chiefly of reddish
porphyritic trachyte, in some places stratified on a small scale. A
breccia of fragments of blackish trachyte in a red paste is also fre-
quent. The aqueous and igneous rocks do not alternate ; the lacus-
trine beds do not contain igneous materials, and no dikes are observed.
On the south side the trachyte overlies the lacustrine formation like
a lava coulee, the uppermost bed of the latter in contact with the
trachyte being a conglomerate of hippurite limestone and schist with
no traces of igneous matter.

Mount Pagus, south of Smyrna, is chiefly trachyte overlying the
lacustrine beds, which crop out on the north side and dip towards
the centre of the hill, consisting of sandy strata with vegetable re-
mains and shells of helix and unio, and between them and the tra-
chyte is the limestone conglomerate. At the north-east foot of the
hill is a small isolated mass of yellowish schist and hippurite lime-
stone about an acre in extent.

The north side of Smyrna bay presents appearances analogous to
those on the south. The grey hippurite limestone of Mount Sipylus
is accompanied as at Mount Tartali by black and greenish schists.
The lacustrine deposits are overlaid by a great mass of trachyte
which forms the lofty mountain of Cordileon. The relation of the
lacustrine beds to the grey hippurite limestone is well exposed in a
ravine north of Bournabat j and a few yards further north they con-
tain beautiful impressions of leaves referred to the genera Laurus,
Nerium, Olea, Salix, Quercus, and Tamarix ; also shells of Cyclas,
Paludina, Planorbis, and Cypris. In ascending hence to the west
the lacustrine marls are surmounted by non-volcanic conglomerate,
identical with that of Mount Pagus. Above this are beds of tufaceous
conglomerate, and at the top the brown trachyte of Cordileon, resem-
bling that near Smyrna, and like it sometimes laminated, but pre-
senting little variety except in a long ridge opposite Smyrna which
consists of whitish decomposed earthy trachyte.

A letter was next read addressed to Sir Charles Lemon, Bart.,
F.G.S., by R. W. Fox, Esq., " On the process by which Mineral
Veins have been filled *."

[* See Lond. and Edinb. Phil. Mag., vol. ix. p. 387, vol. x. p. 394.]
2D2

204 Geological Society.

Mr. Fox admits that the non-mechanical deposits in mineral veins
may be due, in part, to infiltration from the enclosing rocks j but it
appears to him, that such deposits might have been derived in almost
indefinite quantities, by the circulation or ascension of currents of
heated water from the deeper parts of the original fissures. He says,
that water in this state possesses very great powers as a solvent, and
would therefore become highly charged with earthy and metallic salts j
but that in ascending it would lose its temperature, and consequently
deposit the solutions against the sides of the veins.

He is of opinion, that the arrangement of the ore in different rocks,
cannot be due to simple chemical affinity only, because the accumula-
tion of the metallic masses is not found, in Cornwall at least, to depend
on the nature of the containing rock, the ore of a given metal being
sometimes found in granite, sometimes in elvan, sometimes in killas.
This preference of one rock to another he conceives may have re-
sulted from the relative position of the mineral masses, but to be
chiefly due to electricity.

Extracts from two letters " On the Earthquake in Syria in January
last}'' addressed by Mr. Moore, his Majesty's Consul-General at
Beyrout, to Viscount Palmerston, and communicated by J. Back-
house, Esq., and the Hon. W. T. H. Fox Strangways, F.G.S., Under
Secretaries of State, were also read.

The first letter, dated Beyrout, Jan. 2nd, 1837, announces that the
earthquake was felt in that city at thirty-five minutes past four o'clock
in the afternoon of the preceding day. It was accompanied by a
rumbling noise, which lasted about ten seconds, and appeared to pro-
ceed from the north. No buildings were thrown down in the town, but
seven or eight without the walls, and one or two lives were lost. In
the neighbourhood of Beyrout the course of the river Ontilias was
suspended, and mills built on its banks were deprived of water for
some hours. When the stream returned it was turbid, and of a red-
dish sandy colour.

During the day of the earthquake the atmosphere was close and
charged with electricity. Fahrenheit's thermometer stood at 66°,
but five minutes after the earthquake it rose to 70°. Four or five mi-
nutes after the shock the compass was still agitated. The oldest
inhabitants did not remember so severe an earthquake.

The second letter was written also at Beyrout, partly on the 9th
of January, and partly on the 23rd. It contains detailed accounts of
the damage which had been done to numerous towns and villages.
At Damascus, four minarets and several houses were thrown down j
and at Acre, part of the walls and some buildings. Saffet was en-
tirely destroyed, and nearly all the population, amounting to between
four and five thousand, perished. The ground near the city was
rent into fearful chasms, and up to the last accounts shocks were
felt daily. Tiberias was also entirely destroyed, except the baths ;
and the lake rose and drowned many of the inhabitants. The
dispatch contains a list of thirty-nine villages which had been totally
destroyed, and six partially; and Mr. Moore says, it had been ascer-
tained that the earthquake was felt on a line of five hundred miles in

Mr. Owen on the Toxodon Platensis, 205

length by ninety in breadth. It was also perceived in the island of
Cyprus.

April 1 9 — A paper was read, entitled " A description of the Cra-
nium of the Toxodon Platensis, a gigantic extinct mammiferous spe-
cies, referrible by its dentition to the Rodentia, but with affinities to
the Pachydermata and the Herbivorous Cetacea-," by Richard Owen,
Esq., F.R.S., Hunterian Professor of Anatomy to the Royal College
of Surgeons*.

The author premises his anatomical description of the present
fossil, by an abstract from Mr. Darwin's account of the geological
structure of the district in which the cranium was found, from which
it appears that it was imbedded in a whitish argillaceous earth,
forming part of the banks of the Sarandis, a small stream entering
the Rio Negro, and about 120 miles distant to the north-west'of
Monte Video.

The foundation of the whole surrounding country is granitic, but
covered, often to a considerable thickness, by a reddish argillaceous
soil, containing small calcareous concretions.

The cranium in question equals in size that of the hippopotamus,
measuring two feet four inches in length, and one foot four inches in
extreme breadth.

The form of the skull is elongate, depressed, and chiefly remark-
able for the strength and wide expanse of the zygomatic arches,
and the aspect of the occipital foramen and occipital region of the
skull, which slopes from below upwards and forwards. The maxillary
portion of the skull is compressed laterally, narrow, with large inter-
maxillary bones, slightly dilated at their extremity.

The teeth consist of molars and incisors. The latter are four in
number in the upper jaw, the two middle ones very small, the two
external ones very large, curved, and with their sockets extending back-
wards in an arched direction, through the intermaxillary bones to the
maxillary, and terminating, without diminishing in size, immediately
anterior to the grinding teeth, where the large persistent pulps of
these incisors were lodged. In form and relative size these teeth
must have resembled the dentes scalprarii of the Rodentia.

The molar teeth no less present a close approximation in their
form and structure to the molar teeth of the herbivorous rodents j as
is demonstrated in the detailed descriptions of one of these teeth found
by Mr. Darwin in another locality, but belonging to the same species
of Toxodon, and to an individual of the same size as that to which
the cranium here described belonged ; and of a portion of another
molar lodged in one of the sockets of the same cranium. The molar
teeth are seven in number on each side of the upper jaw, and from
the form of the sockets appear to have corresponded with each other
in structure.

After this description of the teeth, the form, proportions, disposition
and connections of the different bones of the cranium are pointed out;
and the structure of the osseous cavities subservient to the organ of

[* See our last volume, p. 404.]

206 Geological Society, — Mr. Darwin on the Deposits

sense is adverted to $ and deductions as to the aquatic habits of the
Toxodon are founded on these observations.

So far as regards the form and position of the external aperture of
the bony nostrils, and of the occipital condyles, and the slope of the
plane of the occipital region of the skull, the same arguments might
be advanced for referring the Toxodon to the mammiferous group
containing the Dugong, as have been recently urged in reference to
the Dinotherium, but the existence of air-cells or sinuses in the su-
perior parietes of the cranium in the Toxodon, show that the cranial
characters above alluded to, are not conclusive as to the cetaceous
nature of an extinct mammal.

The general conclusions respecting the affinities which the Toxodon
bears to existing orders of mammalia, so far as opinions can be
formed from the portion of the skeleton preserved, are summed up
by the author as follows :

So far as dental characters have weight, the Toxodon must be re-
ferred to the rodent order ; but from this order it deviates in the
relative position of the supernumerary incisors, and in the number
and direction of the curvature of the molars.

It again deviates in the transverse direction of the joint of the
lower jaw, and in the relative position of the glenoid cavities and
zygomatic arches. In the aspect of the plane of the occipital fora-
men, and occipital region of the skull, in the form and position of
the occipital condyles, — the aspect of the plane of the bony aper-
ture of the nostrils, and in the thickness and texture of the osseous
parietes of the skull, the Toxodon deviates both from the Rodentia
and existing Pachydermatu , and manifests an affinity to the Dino-
therium and the Cetaceous order.

The author observes, however, that the development of the nasal
cavity and the presence of frontal sinuses, render it extremely im-
probable that the habits of the Toxodon were so exclusively aquatic
as would result from the total absence of hinder extremities, and
concludes, therefore, that it is a quadruped, and not a Cetacean ; and
that it manifests an additional step in the gradation of mammiferous
forms leading from the Rodentia, through the Pachydermata to the
Cetacea ; a gradation of which the water-hog of South America
(HydrochcerusCapybara) already indicates the commencement amongst
existing Rodentia, of which order, it is interesting to observe, that
this species is the largest, while at the same time it is peculiar to the
continent in which the remains of the gigantic Toxodon were dis-
covered*.

May 3. — A paper was first read, entitled "A Sketch of the Depo-
sits containing extinct Mammalia in the neighbourhood of the Plata;"
by Charles Darwin, Esq., F.G.S.

Mr. Darwin premised his account of the geological features of the
district in which the remains of the Toxodon, described at the meet-
ing on the 19th of April by Mr. Owen, as above, were found, by re-
marking that as the other mammalia and the fossil shells had not yet
been accurately examined, the notice was necessarily imperfect.
[* See note *, p. 208.]

containing extinct Mammalia near the Plata, 207

To the westward and southward of the great estuary of La Plata,
extend those level and almost boundless plains which are known by
the name of the Pampas. Their geological constitution over many
hundred square miles does not vary. It consists of a reddish argil-
laceous earth, which generally contains irregular concretions of a white
aluminous limestone, or indurated marl, often passing irregularly into
a compact calcareous stone, traversed by small linear cavities, si-
milar to those which occur in many of the freshwater limestones of
Europe. In the province of Entre Rios, the formation which
composes the surface of the Pampas overlies and passes into a
series of beds of sand, clay, and crystalline cellular limestone ;
containing sharks' teeth, gigantic oysters, and other shells belong-
ing to the genera area, venus and pecten. These shells, with the
exception of the oyster, have a general resemblance to existing
species. To the northward and eastward of the Plata, the province
of Banda Oriental, though very low and level, consists of gneiss,
granite and primary slate. These rocks are generally concealed by a
considerable thickness of a reddish earth, which, though at first sight
like ordinary detritus, belongs to the same formation with that
composing the Pampas. This deposit, extending over so wide an
area on both sides of the Plata, abounds with very numerous remains
of various extinct mammalia -, among which the Toxodon, Mega-
therium, Mastodon, an animal covered with an armadillo-like case, and
as Mr. Darwin believes, the horse, co-existed in the same district.
Proofs of the elevation of the land within a recent period, occur in
several parts. Mr. Darwin stated that he had seen in the possession
of Sir W. Parish, marine shells which occur near Buenos Ayres in
great beds, elevated several yards above the level of the river; and
these same species the author had found living on the mud banks on
another part of the coast. He, therefore, inferred, that at no very
remote period a great bay occupied the area both of the Pampas and
of the lower parts of Banda Oriental ; and that into this bay the
several rivers, which now unite to form the Plata, poured down red-
dish sediment, resulting, as at the present day, from the decompo-
sition of the granites of Brazil, and charged with carbonate and sul-
phate of lime, perhaps derived from the Cordillera. On the cliff-formed
shores of Entre Rios, the line can be distinguished where the estuary
mud first encroached on the deposits of the ocean. The author also
supposed that the ancient rivers, like those of the present day, car-
ried down the carcases of land animals, which thus became entombed
in the accumulating sediment. Since that period, by the gradual
rising of the land, the bottom of the great bay has been converted
into plains, almost as level as the surface of the former sea; and the
rivers now hollowing out courses for themselves, have exposed, in many
places, the skeletons of those ancient inhabitants of the neighbouring
land.

Mr. Darwin then briefly alluded to a small formation of mud and
shingle at Bahia Blanca, some hundred miles south of the Plata, in
which the remains of several extinct quadrupeds have been dis-
covered. Amongst these he enumerated the Megatherium Cuvieri, the

208 Geological Society,

remains perhaps of a smaller species of Megatherium ; a quadruped
closely allied to the armadilloes, but nearly as large as a horse j some
small rodents, and other animals. These remains are embedded with
one species of terrestrial, and several of marine shells, the latter
being identical with some existing in the adjoining bay. It is, there-
fore, certain that the greater number of the above mammalia found
at Bahia Blanca lived within a very recent epoch j and from the po-
sition of the bed in which they occur, it is equally certain that the
form of the land has undergone, since that period, very little change,
even of level, with respect to the ocean.

Several hundred miles further southward, Mr. Darwin found the
remains of an animal which Mr. Owen says has an affinity with the
Llama or Guanaco, but was of a gigantic size : this animal likewise
existed since the Atlantic has been peopled by the shells now living.

The author observed in conclusion, that the comparative recent-
ness of the epoch at which the fossil mammalia lived, is shown, first
by the shells associated with them ; secondly, by the recent tertiary
character of the strata underlying the deposit containing those re-
mains ; and thirdly, from the little altitude of such beds above the
level of the sea ; for in this country, according to the author's obser-
vations, the movements seem to have been so regular, that the amount
of elevation becomes a measure of time.

These facts relating to the former existence of the inhabitants of
a part of the globe so remote from Europe, fully confirm the re-
markable law, often insisted upon by Mr.Lyell, that u the longevity
of the species " among mammalia has been of shorter duration than
among molluscs. The author finally remarked, that although several
gigantic land animals, which formerly swarmed in South America,
have perished, yet that they are now represented by animals, confined
to that country; and which, though of diminutive size, possess the
peculiar anatomical structure of their great extinct prototypes*.

An extract of a letter, dated Saharunpore, 18th November, 1836,
from Captain Cautley to Dr. Royle, was next read j permitting the
announcement of a fact which had long been communicated to the
latter, of the finding of the remains of a quadrumanous animal in the
Sewaliks, or Sub- Himalayan range of mountains. An astragalus
was first found, bu: latterly a nearly perfect head, with one side of
the mohrs ann one orbit nearly complete. The animal must have
been much larger than any existing monkey, and allied to Cuvier's
Cynocephaline group f. Captain C. also announced the discovery by
Major Colvin of a specimen of the head of the Sivatherium, in which,
in conformity to the conjectures of Dr. Falconer and himself, in their
paper, it is found that the animal had four horns, two in front and

[* The relation between the extinct and living animals confined to Ame-
rica was first noticed, we believe, by Mr. Brayley, in some remarks on a fossil
vertebra from Eschscholtz Bay ; probably referable to a species of Mega-
therium. Phil. Mag. and Annals, vol. ix. p. 418.]

[•f See Lieuts. Baker and Durand's accounts of this fossil in our last num-
ber, p. 33.]

Geological Society. 209

two large trifurcated ones behind. Me considers the animal to be
allied to the Dicranocerine group of Major Hamilton Smith*.

Capt. C. also mentions the discovery of a large bear, as well as of
a camel, respecting which he had, in conjunction with Dr. Falconer,
published a paper. Mastodon's heads were also making their ap-
pearance, perfectly different in form from the proboscidean Pachy-
dermata of the present day. There appeared to be altogether two
if not three species, besides the variety of M. angustidens.

A paper was then read " On some recent elevations of the Coast
of Banffshire; and on a deposit of clay, formerly considered to be
lias;" by Joseph Frestwich, jun., F.G.S.

That an uplifting of the shores of the Moray Firth has taken place
subsequent to its having assumed its present outline, is proved by
the existence, in several places, of a raised beach. In Banffshire
this beach varies from six to twelve feet above the present high water
level ; and occasionally abounds in shells now inhabiting the adja-
cent seas, as Patella vulgata, P. levis, Trochus ziziphinus, Littorina
littorea, and Turbo returns. To this upheaving of the land the author
attributes the draining of the former lowlands, as he conceives is
indicated by the remains of drained peat-mosses. A section of one
of these presented a total thickness of about four feet, including two
irregular layers of gravel, of quartz grit, with freshwater and land
shells.

In a paper on the Gamrie Ichthyolites, read before the Societv in
April 1835f, Mr. Prestwich stated, that having been informed of the
occurrence of lias fossils in the dark clay and sand, which in many
parts of Banffshire cap the old red sandstone and schistose rocks, he
had inferred that these beds might be outliers of lias. Having
however subsequently visited the country, and examined that de-
posit at Blackpots and Gamrie, he found the lias fossils in separate
masses and associated with rolled fragments of the older rocks. He
also met with at Gamrie, in a bed of light coloured sand, alternating
with dark clay and beds of gravel, the following recent shells, As-
tarte Scotica, Tellina tenuis, Buccinumitndatum, Natica glaucina, Fusus
iurricola, Dentalium dentalis, &c. They were extremely friable, but
perfect. This deposit or drift attains, in places, a thickness of 250
feet, and rises to a height of 350 feet.

In conclusion, the author attributes the origin of this drift to a
denudation of the lias and older formations ; and he infers, from
the perfect preservation of the fossils, and the superposition of the
beds, that its accumulation was gradual.

A paper was afterwards read, entitled " An account of a Tertiary
Deposit near Lixouri, in the island of Cephalonia ;" by William John
Hamilton, Esq., F.G.S. , and Hugh Edwin Strickland,' Esq., F.G.S.

The authors state that most of the island of Cephalonia which they
had an opportunity of examining, consists of a hard white limestone

[* Dr. Falconer's and Capt. Cautley's Memoir on the Sivatherium will be
found in Lond. and Edinb. Phil. Mag., vol ix. p. 193. et ieq.J

f Geological Proceedings, Vol. ii. No. 40, or Lond. & Edinb. Phil. Mag.,
vol. vii. p. 325.

Third Scries. Vol. 1 1. No. 66. Aug. 1837. 2 E

210 Geological Society.

or scaglia, occasionally more or less crystalline, which forms the
principal rock of the Ionian islands. It is generally without fossils,
but near Argostoli contains numerous organic remains, principally
small spiral univalves; and near the middle of this vast formation are
two beds of oyster shells, about a foot thick each, and parallel to the
stratification which dips to the north-east at an angle of 25°.

The tertiary formation extends for two or three miles to the north
and south of Lixouri, forming several parallel lines of hills, sloping to
the east according to the dip of the strata, and presenting a suc-
cession of steep escarpments toward the west. The beds are all
conformable, dipping a few degrees to the north of east by compass,
at an angle varying from 45° to 55°. These beds are remarkable
for their great thickness, the beauty and number of their fossils ; and
for the variety of strata through which they extend. The beds, of
which sixteen are enumerated, may be classed under three principal
heads. First, the calcareo-arenaceous ; second, the argillaceous j
third, the gypseous beds. Of these, the first is a loose sandy alluvium,
rising very gradually from the sea side, and resting unconformably
upon the other beds which are. conformable. The fossils belong to
numerous genera ; and some of the species have been identified with
those at present existing in the Mediterranean.

May 17. — " A description of the Geological character of the Coast
of Normandy ;" by S. Peace Pratt, Esq., F.G.S., begun at the meet-
ing on the 3rd of May, was concluded.

The author commences his paper by observing that the fall of a cliff
or the opening of a quarry throws light upon an obscure locality and
clears up previous difficulties; and that from frequently examining
the coast from Point Antifer to near Grenville, he has had opportuni-
ties of correcting some of the views of M. De la Beche and M. De
Caumont in their descriptions of the same line of coast.

The chalk cliffs from Point Antifer to Cap la Heve are composed
of craie glauconeuse equivalent in position to chalk marl. These
rest on a bed 40 to 50 feet thick of green sand, containing nume-
rous fossils ; the lower part, of a dark olive green, is also full of shells
and corals. To these succeed two argillaceous beds with an inter-
mediate one of ferruginous sand, each five to seven feet thick, resting
upon a fourth 20 to 25 feet thick of sand, in which the plates of mica
are numerous and large. These beds are interesting as indicating the
presence of the gault, lower green sand, and Hastings sand. The
absence of the characteristic fossils may be explained by the beds ap-
pearing to have thinned off towards the coast.

The ferruginous deposit rests upon an argillaceous limestone, sepa-
rated into thin beds by partings of clay, then rising to the surface at a
small angle to the north-east of Cap la Heve. The upper layers of
the clay contain Gryphcea virgula, Ostrani deltoidea, &c, while in the
marl stone, though there are few fossils, a Pholadomya, a Terebratula,
&c, were occasionally found in the upper parts with Trigonia and
Perna, in the lower parts generally in distinct beds. These therefore
represent the Kimmeridge clay, though found immediately under the
iron sand.

Geological Society. 2 i 1

On the south bank of the Seine, though the cliffs appear similar,
yet in consequence of a fault the lower argillaceous bed which covers
the ferruginous sand has been brought down to the level of the shore ;
and has led to the error that the argillaceous beds on the two shores
were of the same age ; and that the argile (VHonfleur, like that on the
north bank, was identical with the Kimmeridge clay, though it ac-
tually overlies the iron sand.

Beyond Honfleur a marshy plain succeeds, composed to the depth
of two feet of a marl containing such freshwater shells as Lymnaea,
Cyclas, Planorbis, &c. At Cricque-boeuf a bed of clay, similar to that
at Havre, rises to the surface, covered by a few inches of the green
and ferruginous sands ; and as the characteristic shells are found in
its upper part there can be no doubt of this also being analogous to
the Kimmeridge clay. About a mile to the westward it is seen rest-
ing on a calcareous close-grained rock, which from its nature and
fossil shells, and abundance of coral, the author considers equivalent
to the coral rag ; and states that the upper part cannot represent the
Portland beds, for the whole distinctly underlies the Kimmeridge
clay. Near the mouth of the Toncque a deposit of clay rises from
beneath these calcareous strata, alternating with their lower beds and
forming bold cliffs from near Villers-sur-mer to Dives. Fossil remains,
both animal and vegetable, are abundant j in the upper part Gry-
phcea dilatata and Ostrea gregarea in numerous thin beds. The remains
of vertebrated animals are not very numerous, but bones of saurians
and fishes are occasionally found. Mr. Pratt gives a list of the fos-
sils found in the Argile de Dives, which he assimilates to the Oxford
clay.

This clay is again seen at a short distance from the mouth of the
Orne overlying a calcareous oolitic group, consisting of numerous
fissile beds full of shells and fragments of coral, usually considered
identical with the cornbrash ; but which Mr. Pratt considers as ap-
proaching much nearer to the forest marble of the west of England.
Thev pass into others less oolitic, containing numerous genera of co-
rals and shells, and overlie two beds of marly rubbly stone passing in
their lower parts into a clay filled with fossils chiefly of Terebratula
digona and plicata, Avicula i?iaquivalvis, Jpiocrinites rotundus, &c.
Together they form a mass about eight feet thick, but varying at
short distances and resting upon a hard crystalline limestone, verv
little oolitic, composed of broken shells and corals, stems of Encri-
nites and Pentacrinites, and the corals for which this locality is
famous in the fissures. This stone is generally thought to pass into
the freestone of Caen ; the author thinks it more probable that it
overlies it, but thins off towards the S.W. The Caen stone is usually
considered to represent the great oolite, but Mr. Pratt remarks that
the few fossils found in it, as Terebratula ipiwsa, Sec, resemble
those of the inferior oolite. In examining the cliffs near St. Hono-
rine, the lias, in consequence of a fault, may be seen for a few hun-
dred yards forming their base. The contact of the lias filled with
Belemnites with the inferior oolite is here marked by a highly ferrugi-
nous oolitic bed, only a few inches in thickness, but containing almost

2E2

212 Geological Society,

as many fossils as when of its greatest thickness. These are gene-
rally identical with those found at Dundry. Upon this bed rests the
sandy calcareous rock, 25 feet thick, which has been described by
M. De la Beche as lias. It contains three or four beds full of sponges,
Alcoynia, a few shells, and numerous Echini, and is surmounted by
an argillaceous deposit varying from light grey to dark blue, and as-
suming at Port en Bessin a thickness of more than 100 feet, but is
not separately distinguished in M. De la Beche's section. From geo-
logical position it appears to represent the Fullers' earth. This clay
is covered by a calcareous rock slightly oolitic, containing few or no
fossils, and forming the summit of the cliffs from St. Coine to Gran-
ville.

Mr. Pratt concludes his paper by observing that nearly the whole
of the strata found between the chalk and the lias in England are
found on the coast of Normandy, though somewhat modified ; and
that nearly all the characteristic shells are found in each. No bed
of any consequence found in Normandy is wanting in the English
series ; while the Portland and perhaps the Purbeck beds with the
Kelloway rock are not seen in this part of France.

Extracts from a letter from Sir John F. W. Herschel to C. Lyell,
Esq., dated Fredhausen, Cape of Good Hope, 20th February, 1836,
were then read

The author commences by inquiring, whether it had ever occurred
to Mr. Lyell to speculate on the probable effect ofthe transfer of pressure
from one part to another of the earth's surface by the degradation of
existing, and the formation of new continents, on the fluid or semifluid
matter beneath the outer crust? Supposing the whole to float on a
sea of lava, the effect would merely be an almost infinitely minute
flexure of the strata ; but supposing the layer next below the crust
to be partly solid and partly fluid, and composed of a mixture of fixtd
rock, liquid lava and other masses in various degrees of viscidity
and mobility ; great inequalities may subsist in the distribution of
pressure, and the consequences may be local disruptions of the crust
where weakest, and escape to the surface of lsiva, &c.

Referring to the phaenomena of volcanos, fcir J. Herschel observes,
that it has always been his greatest difficulty in geology to find a
primum mobile for the volcano, taken as a general and not as a local
phenomenon ; and referring to the different theories given on the
subject, which he considers insufficient, wanting in explicilness and
as not going high enough in the inquiry or up to its true beginning,
and also as giving in some respects a wrong notion of the process
itself; — inquires, how came the gases which are evolved to be con-
densed } — why did they submit to be urged into liquefaction r — if
they were not originally elastic, but have become so by subterranean
beat — whence came the heat, and why did it come ? — how came
the pressure to be removed, or what caused the crack ?

It seems clear that if the gases or aqueous vapour were once free
at so high a degree of elasticity as is presumed, there exists no ade-
quate cause for their confinement. We are forced therefore to ad-
mit that the elastic force has been superadded to them during their
sojourn below by an accession of temperature.

Sir J. Herschel on the Theory of Volcanic Phcenomena. 213

Assuming a high central temperature, which many geologists ad-
mit, and with which all are familiar; the author agrees with Mr.
Lyell's observations, that the ordinary repose of the surface argues
a wonderful inertness in the interior, where in fact he conceives that
everything is motionless; debarred therefore from the invasion of a
circulating current or casual injection of intensely hot liquid matter
from below, he conceives that the phaenomena may be explained as
follows :

Granting an equilibrium of temperature and pressure within the
globe, the isothermal strata near the centre will be spherical ; but
where they approach the surface they will by degrees con form them-
selves to the configuration of the solid portion, that is, to the bottom of
the sea and the surface of continents. If we suppose therefore a state
of equilibrium, and that under the concave bottom of any great
ocean the lines of equal temperature be parallel to its concavity ;
when this comes to be filled up by the deposition of matter brought
down by rivers, etc., the formerly concave bottom may become hori-
zontal or even convex, and the equilibrium of temperature will im-
mediately be disturbed ; because the form of a stratum of tempera-
ture depends essentially on the bounding surface of the solid above
it, that form being one of the arbitrary functions which enter into
its partial differential equation. The temperature, therefore, will im-
mediately begin to migrate from below upwards, and the isothermal
strata will gradually change their forms from the concave to the hori-
zontal or convex form. The former bottom of the ocean will then
(after the lapse of ages, and when a fresh state of equilibrium is at-
tained) acquire a temperature corresponding to its then actual
depth ; while a point as deep below it, as itself is below the surface,
will have acquired a much higher temperature, and may become ac-
tually melted, and this without any bodily transfer of matter in a
liquid state from below. But if the temperature of this supposed
deep stratum be already at the melting point, then will this rise to
the former bottom of the ocean and the strata become melted,
water included, with which, from the circumstances of the case,
they must be saturated.

If the process of deposition go on, until by accumulation of press-
ure on the bottom or sloping sides, some support gives way, — a piece
of the solid crust breaks down and is plunged into the liquid below,
and a crack takes place, extending upwards. Into this the liquid
will rise by simple hydrostatic pressure. But as it gains height it
is less pressed ; and if it attain such a height that the ignited water
can become steam, the joint specific gravity of the column is sud-
denly diminished and up comes a jet of mixed steam and lava ; till
so much has escaped that the deposited matter takes a fresh bearing,
when the evacuation ceases and the crack becomes sealed up.

By taking this viewof the process of heating from below, we have
a strictly theoretical explanation of the effects of heat on newly de-
posited strata ; and this, simply because the fact of new strata ha-
vmgbeen deposited, theconditions of the equilibrium of temperature
become altered, and they draw the heat to them, or rather retain it

214 Geological Society.

in them in its transit outwards; the supply from the centre being
supposed inexhaustible, and its temperature of course invariable.

As the greatest transfer of material to the bottom of the ocean is
produced on the coast line by the action of the sea, while the quan-
tity carried down by rivers from the surface of continents is compa-
ratively trifling ; hence therefore the greatest local accumulation of
pressure is in the central area of deep seas, but the greatest local
relief takes place along the abraded coast lines: here, therefore,
according to this view should occur the chief volcanic vents.

In this view the effects of the removal of matter from above to
below the sea, are, 1st. It produces a mechanical subversion of the
equilibrium of pressure. 2nd. It also, and by a different process,
produces a subversion of the equilibrium of temperature. The last
is the most important. It must be an exceedingly slow process, and
will depend, 1st. On the depth of matter deposited • 2nd. On the
quantity of water retained by it under the great pressure ; 3rd. On
the tenacity of the incumbent mass — whether the influx of caloric
from below, which must take place, acting on that water, shall either
heave up the whole mass as a continent ; or shall crack it and escape
as a submarine volcano; or shall be suppressed until the main weight
of the continually accumulating mass breaks its lateral supports at or
near the coast lines, and opens there a chain of volcanos.

Thus the circuit is kept up— the prirnum mobile is the degrading
power of the sea and rains (both originating in the sun's action)
above, and the inexhaustible supply of heat from the enormous re-
sources below, always escaping at the surface, unless when repressed
by an addition of fresh clothing at any particular part. In this view
of the subject the tendency is outwards. Every continent deposited
has a propensity to rise again, and the destructive principle is con-
tinually counterbalanced by a reorganizing principle from beneath.
Nay, it may go further ; there may be such a tendency in the globe
to swell into froth at its surface, as may maintain its dimensions in
spite of its expense of heat, and thus preserve the uniformity of its
rotation on its axis*.

An Extract of a letter from Sir John F. W. Herschel to R. I.
Murchison, Esq., in explanation of the former, to C. Lyell, Esq.,
dated Fredhausen, 15th November, 1836, was afterwards read.

In this letter the author recapitulates the views given in the fore-
going abstract, stating that his views are not so much a theory as a
pursuing into its consequences, according to admitted laws, of the

[* On the subject of the views here enunciated by Sir John Herschel,
see a notice of a paper by Mr. Babbage, Lond. and Edinb. Phil. Mag. vol.
v, p. 213. Mr. Babbage has since published the substance of his paper in
his work entitled " The Ninth Bridgewater Treatise," together with the ex-
tracts from Sir J. Herschel's letters, abstracted above. He observes, in re-
ference to the similarity of Sir J. Herschel's views to those he had himself
previously started, " I feel, that the almost perfect coincidence of his views
with my own, gives additional support to the explanations 1 have offered;
whilst the reader will perceive, from the different light in which my friend
has viewed the subject, that we were both independently led to the same
inferences by different courses of inquiry." — Edit.]

Geological Society. 2 1 5

hypothesis of a high central temperature ; and his object to get a
geological primum mobile in the nature of a vera causa, and to
trace its workings in a distinct and intelligible manner, so that in
future, instead of saying as heretofore, " Let heat from below invade
newly deposited strata, then they will expand, melt," &c, we shall
commence a step higher, and say, " Let strata be deposited, then, as
a necessary consequence, and according to known regular and cal-
culable laws,heat will gradually invade them from below and around j
and according to its due degree of intensity at any assigned time
will expand or melt them as the case may be," &c. The phenomena
of earthquakes, volcanic explosions, &c., may arise, but if all goes
on in quiet, the only consequences will be the obliteration of organic
remains and lines of stratification, and the formation of new combi-
nations of a chemical nature, &c. ; in a word, the production of me-
tamorphic or stratified primary rocks.

In the formation of these therefore there is nothing casual ; all
strata once buried deep enough, and due time allowed, must assume
that state. None can escape j all records of former worlds must
ultimately perish.

" An account of a Well at Beaumont Green in the County of He-
reford, fifteen miles from London, about a mile to the west of the
road to Ware ;" by J. Mitchell, LL.D., F.G.S., was last read.

This well was dug in 1833, in the premises of Mr. Munt, a magi-
strate of the county, and the information respecting it obtained from
two gentlemen accustomed to collect evidence with the strictest
scrutiny.

The strata passed through, were one foot vegetable mould, 15 feet
gravel, one loot sand with flints, 83 feet gravel clay, 15 feet blue
sand with black pebbles, 10 feet blue clay, \\ feet fine soft white
sand, or 126 J feet down to the chalk, which was penetrated for 40
feet when a spring was met with; but the digging continued 17 feet
lower to form a reservoir of water, and this was favoured by making
the excavation in the chalk of a bell shape, but above this the well
was 4£ feet in diameter.

When the well was dug the weather was dry, but on this beco-
ming very wet the 15 feet stratum of blue sand and black pebbles be-
gan to emit foul air, by which one of the well-diggers was suffocated
in descending. A hawk flying over the well fell into it, and a similar
fate befell smaller birds, also wasps, bees and flies. On closing up
the mouth of the well, with the exception of an orifice an inch in dia-
meter, so powerful was the force of the issuing current of foul air
that it raised a weight of twelve ounces of lead. In fine weather
there was on the contrary a strong draft down into the well.

Eight months afterwards the well was again entered when the
stratum of blue sand and black pebbles appeared forming into plum-
pudding stone. The well was rendered safe by bricking it down to
the chalk, applying a thick coating of compost over the whole. Dr.
Mitchell explains the phaenomena, by observing that the foul air was
no doubt sulphuretted hydrogen, produced by the decomposition of
water and iron pyrites. After long-continued rain j water penetrating

2 1 6 Intelligence and Miscellaneous Articles,

into the bed dislodged the gas accumulated in the interstices where
it was formed j while, after dry weather had continued for some
time, the openings produced in this bed on drying up would draw
for a short time a supply of air to fill up the vacuities, and hence
the draft observed to pass down into the well. The whole of the
neighbouring district, to the extent of four miles, is called by the
well- diggers, foul country. Similar phaenomena were observed in
digging a well on the opposite hill at Applebury, and also(in form-
ing some wells in the immediate vicinity of London.

XXIV. Intelligence and Miscellaneous Articles,

ON THE ACTION OF IODINE UPON THE VEGETABLE ALKALIS.
BY M. PELLETIER.
[Continued from vol. x. p. 503 and concluded.]
Iodine and Brucia. — Iodine when put into contact with brucia
renders it of a brownish yellow colour ; when heated with water
the mixture at first yields iodine, the compound softens like a resin-
ous body, but without perfectly melting ; on cooling it becomes
brittle. The solution when filtered and evaporated leaves a brown
substance with some traces of crystals.

The mass is totally soluble in hot alcohol; on cooling a very light
brown powder separates ; the solution yields by slow evaporation a
further quantity of it, and towards the end of it, crystals of hvdri-
odate of brucia in transparent quadrilateral prisms, are obtained.

The formation of the hydriodate of brucia appears to be derived
from the reaction of the iodine upon alcohol, which is well known
to produce hydriodic acid. A brown matter is also formed when
water is employed, but in this case there are mere traces of hydri-
odate.

The brown matter is iodide of brucia ; with chemical agents its
appearances are similar to those of iodide of strychnia, except such
as depend upon the difference of the bases: heated with the diluted
mineral acids it yields salts of brucia, and with concentrated nitric
acid it gives the fine red colour which characterizes brucia.

It has already been shown that the iodide of strychnia is a neutral
compound, but that of brucia is a bi-iodide composed of

Two equivalents of iodine 252 or 47*72

One equivalent of brucia 276 „ 52*28

523 10O

A neutral iodide of brucia was obtained by mixing and agitating
cold tinctures of iodine and the alkali, not adding enough of the
former to constitute a bi-iodide. An orange-coloured precipitate
is obtained, which is a neutral iodide, composed of nearly

One equivalent of iodine 126 or 31 34*

One equivalent of brucia 276 „ 68-66

402 100-

Intelligence and Miscellaneous Articles, 217

lodate of Brucia. — Iodic acid combines directly with brucia; if the
acid be in excess a red colour appears, but otherwise it is colourless.
By evaporating the solution two salts are obtained : one, which is
opaque and silky, with excess of base, and which restores the colour
of litmus reddened by an acid ; the other is transparent, hard, and
in four-sided prisms, this reddens litmus paper. The subsalt has such
a disposition to form that it may frequently be obtained in crystals,
even from a solution which is slightly acid.

Hydriodate of Brucia. — This salt may be obtained by directly
treating brucia with hydriodic acid ; it has a different appearance
from hydriodate of strychnia, the crystals are transparent square la-
minae or short four-sided prisms. Though slightly soluble in cold
water, it is more so than hydriodate of strychnia; hot water dissolves
more than cold, and crystals are obtained on cooling. It is more
soluble in alcohol than in water. Hydriodate of brucia may be pre-
pared by double decomposition by adding hydriodate of potash to
sulphate of brucia. It is a subsesquihydriodate, composed of

One equivalent of hydriodic acid .... 127 or 23*47
One and a half equivalent of brucia . . 4-14 „ 76*53

54-1 100-

The phenomena which have been noticed when treating of hy-
driodate of strychnia with respect to the action of iodic acid or of an
acid poured into a mixture of iodate and hydriodate, also take place
when hydriodate of brucia is similarly treated.

Iodine and Cinchonia. — To obtain iodide of cinchonia the alkali
must be triturated with about half its weight of iodine and treated
with alcohol ; the whole dissolves, and by spontaneous evaporation
iodide of cinchonia is obtained in plates of a saffron colour ; the
iodide separates before all the spirit evaporates ; towards the end
of the operation, crystals of hydriodate of cinchonia are deposited in
the form of mushrooms. On treating the whole with boiling water
the hydriodate dissolves and fused iodide remains.

In mass the iodide of cinchonia is of a very deep saffron colour ;
in powder its colour is lighter, its taste is slightly bitter. When
heated to 77° Fahr. it softens, but does not fuse below 176°. It is
insoluble in cold water, and very slightly dissolved by it when boil-
ing. It dissolves in alcohol and in aether. It is decomposed by the
alternate action of acid and alkaline solutions.

It is a di-iodide, composed of

One equivalent of iodine 126 or 29

Two equivalents of cinchonia 308 „ 71

4-^4- 100

Iodate of Cinchonia. — This salt has been described and analysed
by Serullas. M. Pelletier observes that he has only to add to his
account of it that it is very soluble in water, which is remarkable in
a salt that is insoluble in alcohol.

Third Series. Vol. 11. No. 66. Aug. 1837. 2 F

218 Intelligence and Miscellaneous Articles.

It is a di-iodate composed of

One equivalent of iodic acid 166 or 35

Two equivalents of cinchonia 308 „ 65

474 100

Hydriodic Acid combines very readily with cinchonia. It cry-
stallizes in transparent and slender needles of a pearly lustre. It is
slightly soluble in cold water, more soluble in hot, and on cooling
it crystallizes. Its taste is at first but slight ; but it is developed in
a short time and is bitter and metallic. The hydriodate and iodate
of cinchonia may remain some time together without decomposing;
but eventually, and especially when the solutions are concentrated,
iodide is deposited ; when acid is present the decomposition occurs
rapidly.

Iodine and Quina. — Iodine acts upon quina similarly to cinchonia ;
it is difficult to distinguish the iodides from each other on account
of their great resemblance as to appearance, colour, taste, and
fusibility.

It is probably composed of

One equivalent of iodine 126 or 27*75

Two equivalents of quina 328 „ 72-25

454- 100-

Iodate of Quina. — This salt is less soluble than the iodate of cin.
chonia. M. Pelletier did not make a direct analysis of it, but con-
cludes from the constitution of the iodide that it is composed of

One equivalent of iodic acid 166 or 33*6

Two equivalents of quina 328 „ 66 4

494 100-

Hydriodate of Quina may be obtained either by direct action or
double decomposition. Its crystals are more slender but less trans-
parent and soluble than those of hydriodate of cinchonia ; they have
a tendency to the mammillated form.

Iodine and Morphia. — Iodine acts in a much more complicated
manner upon this than the other alkalis. If morphia be triturated
with one fourth of its weight of dry iodine, the matter becomes of a
reddish brown colour, without yielding any smell of iodine ; but
after some hours have expired, its colour changes to a violet brown
and even to a black, and a smell of iodine is perceptible. It seems
as if the iodine separates after being sometime combined with the
morphia.

Morphia, triturated with half its weight of iodine, exhibited simi-
lar phaenomena, but with greater rapidity. The product was inso-
luble in cold water but plentifully dissolved by it when boiling. The
solution was acid when half a part of iodine was employed, but neu-
tral with a smaller proportion y but much hydriodate of morphia

Intelligence and Miscellaneous Articles. 219

was held in solution. This formation of hydriodic acid is remarkable,
and does not occur with the other vegetable alkalis.

A mixture of equal parts of iodine and morphia totally dissolved
in boiling alcohol. The solution was acid, and yielded by sponta-
neous evaporation a red brown substance as the alcohol was dissi-
pated. There remained, at length, an aqueous, slightly coloured
liquor, which when poured off and set to evaporate in another vessel,
yielded crystals of hydriodate of morphia deeply coloured with
iodine. Various means were tried to determine the nature of the
red brown substance, but it never yielded morphia when a sufficient
quantity of iodine had been employed. When treated with sul-
phuretted hydrogen in order to convert the iodine into hydriodic
acid, and obtain an hydriodate from which the morphia or the sub-
stance which replaced it might be separated, ammonia, added to
the clear and colourless solution, rendered it immediately of a dirty
red colour. The precipitate formed was exceedingly light, not at
all corresponding to the quantity of morphia employed, and con-
tained no trace of it ; but the solution contained an organic matter.

If instead of treating the solution with an alkali, it be concen-
trated with heat and the sulphuretted hydrogen expelled, a brown
substance, similar to that subjected to the action of the sulphu-
retted hydrogen, is reproduced. It appears therefore that by the
combined agency of air, heat, and the organic matter, the hy-
driodic acid returns to the state of iodine in order to combine with
this matter (the altered morphia) and to precipitate again with it.

Hydriodate of morphia may be prepared by direct action, and
when chlorine is passed into a solution of it, not in excess, a very
light and bulky precipitate of a reddish colour is immediately ob-
tained ; in a few seconds, however, the precipitate becomes black,
diminishes considerably in volume, and iodine separates in abun-
dance, as proved by its colour and smell. The filtered solution is
colourless; but by evaporation it becomes yellow, and hydrochloric
acid is disengaged. If ammonia be added to it, an extremely light
precipitate is obtained which contains no trace of morphia. The
organic matter remains in the liquor, which becomes of a red brown
by exposure to the air. The action of iodine upon morphia is not
prevented by an acid ; thus when sulphate of morphia is treated with
iodine, sulphuric acid is set free, and the reddish brown matter
already described is formed.

After various attempts no definite or permanent compound of
iodine and morphia was obtained, on account of the separation of
the hydrogen of the alkali.

Iodic Acid and Morphia. — It has been shown by Serullas that
iodic acid, which combines with other organic salifiable bases, acts
upon the elements of morphia and its salts ; that at the moment of
contact the mixture became yellowish brown, that iodine was set
free, as evinced by its odour and action upon starch ; two substances
are formed : one of a rose colour and soluble in water, and the other
yellowish brown and but slightly soluble. Serullas does not state
the nature of the former, but the latter he considers as a compound

2 F 2

220 Intelligence and Miscellaneous Articles,

of altered morphia with iodine and iodic acid. The facts stated by
Serullas are important ; the action of iodine upon morphia supplies
an excellent method of ascertaining the presence of the smallest
trace of morphia, and vice versa, of detecting iodine in the state of
iodic acid.

M. Pelletier adds, that when iodic acid is put in contact with
morphia, the first effect is that of reducing the iodic acid. The
oxygen of the acid acts upon the elements of the morphia, probably
upon its hydrogen j hence the formation of the rose-coloured sub-
stance, as when morphia is treated with concentrated nitric acid.
As soon, however, as the iodine is set free, if any uncombined mor-
phia remains, the iodine combines with it, to form the orange brown
matter already described. If this brown matter, obtained as above,
or by the direct action of iodine upon morphia, be again treated
with iodic acid, it is acted upon and the rose-coloured com-
pound is again formed. M. Pelletier remarks that the red substance
derived from the oxygenating action of iodic acid upon morphia
merits a minute comparison with the red matter obtained by the ana-
logous action of nitric acid upon it.

Hydriodic acid combines directly with morphia and forms a white
silky salt, which is more soluble than the hydriodates of the other
vegetable alkalis. In the hydriodic acid, the iodine being saturated
with hydrogen, cannot act upon that of the morphia. But if the hy-
drogen of the hydriodate be separated, the reaction of the iodine on
the morphia then commences and continues.

Iodine and Codeia may be combined by direct action. The
iodide is brown and but slightly soluble in water. When codeia is
treated with an alcoholic solution of iodine, the iodide is also formed,
but the hydriodate is obtained with it. Of all the vegetable alkalis
codeia gives the greatest quantity of hydriodate when treated with
an alcoholic solution of iodine ; probably on account of the greater
solubility of the codeia.

Hydriodate of morphia exists in the mother waters, and it is co-
loured by the iodide. It may be obtained very white by directly
combining the codeia with the hydriodic acid. In external cha-
racters it greatly resembles hydriodate of morphia, but differs from
it essentially in not having its base separated by ammonia. Iodic
acid combines directly with codeia. The crystals contained excess
of acid ; they are very fine flattened needles and fan-shaped.

Although this salt was prepared with codeia, which had been re-
dissolved in aether, the crystals were slightly coloured by a brown
yellowish matter ; this is, however, separated by crystallizing the
iodate repeatedly. The colour appears to be owing to a little mor-
phia retained by the codeia. It is probable that the differences
existing in the ultimate analyses which have been performed are
derived from the presence of a little morphia. M. Pelletier is de-
cidedly of opinion it is neither a compound containing morphia nor
derived from it, as has lately been endeavoured to be proved. — Ann.
de Chim. et de Phys. vol. lxiii, p. 164.

Intelligence and Miscellaneous Articles, 221

ON HYDROBROMATE OF CARBOHYDROGEN (METHYLENE).

The hydrobromate of carbohydrogen discovered by M. Bonnet
is a colourless and extremely volatile liquid of an agreeable and pe-
netrating odour. Although water causes a precipitate in a solution
of it in pyroxylic spirit, yet a considerable quantity is retained in so-
lution; it is also soluble in alcohol and aether, from which it is preci-
pitated by water. It is decomposed by heat. The constitution of
this compound is represented by the formula Br2 H2, C4 H4, —
V Institute Feb. 1837.

ON THE PREPARATION OF SULPHURET OF CARBON.

M. Mulder directs, in an iron bottle in which mercury is im-
ported, that besides the hole which is already there, another should
be bored near it. Into the first of these openings a copper tube
bent twice at right angles is to be screwed, and into the second a
straight tube, also of copper, is to be introduced. Then the bottle is
to be filled with pieces of charcoal, recently heated to redness, of
such a size that they can easily pass down the tube. After having
firmly screwed in the straight and curved tubes, place the bottle in
a furnace and heat it, after having closed the opening of the furnace
with a stone cut in halves to prevent inconvenience to the operator
from the ascending heat.

Adapt to the curved tube a WoulfF's bottle half rilled with water
and surrounded with a freezing mixture, and when the iron bottle
is sufficiently heated, introduce bjr the straight tube fragments of
sulphur and immediately close the mouth of the tube with a plug ;
the sulphur fuses, and falling upon, penetrates the pieces of charcoal,
and when the sulphur is gradually added, but little gas is evolved
and abundance of sulphuret of carbon obtained. — Journal de Phar-
made, Jan. 1837.

SOLUBILITY OF OXIDE OF LEAD IN WATER.

M. De BonsdorfF states that oxide of lead is entirely soluble in
water when it is formed by the action of damp air, or by the de-
composition of nitrate of lead by the application of heat*. — L'ln-
stitut, May 1637.

ANHYDROUS CAMPHORIC ACID, CAMPHOVINIC ACID, AND CAM-
PHORIC iETHER.

According to M. Malaguti, crystallized camphoric acid obtained
by the prolonged action of nitric acid on camphor, and possessing
all the properties of pure camphoric acid, affords by combustion with
oxide of copper :

Carbon 60-20

Hydrogen 8-00

Oxygen 31-79

which indicates the formula C20 H8 O4.

* On this subject see Lond. and Edinb. Phil. Mag., vol. v. p. 81.

222 Intelligence and Miscellaneous Articles.

■o

By boiling camphoric with sulphuric or hydrochloric acid and
alcohol, a bitter substance of the consistence of syrup is obtained,
which is insoluble in water, but dissolves in alkalis, from which it is
precipitated by acids ; it is also soluble in alcohol. This substance,
after having remained some days in vacuo, afforded the following
composition: C4S H20 O8, which gives the formula (O0 H14 O6 -f C8
H> O 4- OH), A.

If camphoric acid be represented by the formula C20 H7 03 + OH,
the formula A will be equal to two equivalents of camphoric acid,
each deprived of an equivalent of water, and replaced by one equivalent
of aether and one of water, which is the exact composition of the
vinic acids. When this substance, camphovinic acid, is distilled in a
glass retort over a lamp, there are produced a butyraceous sub-
stance, inflammable carburetted hydrogen gas, and a carbonaceous
residue. The butyraceous matter treated with boiling alcohol and
the solution gradually cooled, crystals of an extraordinary length
are obtained possessing neither taste nor smell. The crystals are
perfectly neutral, fusing and volatilizing without undergoing de-
composition, and combining, notwithstanding their neutrality, with
bases, forming crystallized salts. They possess a great number of
characteristics, both physical and chemical, which completely di-
stinguish them from camphoric acid.

The crystals are composed of C20 H7 O3, and this formula is com-
pletely confirmed by the analysis of the compounds of this crystal-
line body with the oxides of copper and silver ; so it may be consi-
dered as camphoric acid minus an equivalent of water. But these
crystals, although not possessing an acid re-action, are nevertheless
an acid, forming sether by the combined action of alcohol and a
strong [mineral] acid, and producing the same vinic acid which is
produced by crystallized camphoric acid ; this also is a proof that
crystallized camphoric acid, C20 H8 O4, contains an equivalent of
water, which it parts with when combining with certain bases. What
follows confirms this opinion.

The alcoholic mother liquors from which the anhydrous cam-
phoric acid is precipitated, treated with water, afford a dense oily
product, which boiled for a few minutes with a little potash
becomes very fluid. This has a singular odour, a disagreeable
taste, and volatilizes without decomposition.

The composition of this substance, according to experiments, is
C28 H12 O, corresponding with camphoric sether C20 H7 O3 +
C8 Hb O. In whatever way this sether is obtained, whether by
crystallized camphoric acid or by anhydrous acid, it appears that
in the process of setherifi cation the common camphoric acid parts
with an equivalent of water and becomes anhydrous, consequently
the formula is C20 H7 03 + OH, and that when it enters into com-
bination it loses an equivalent of water, as in the following formulae:

Common camphoric acid = C-° H7 03 + H O.

Anhydrous = O H7 O3.

Camphovinic acid = C40 H14 O + C8 H*0 + HO.

Camphoric aether . . .... = C20 H7 03 + C8 H^ O.

Intelligence and Miscellaneous Articles. 223

Note. — M. Liebig, Ann. de Chimie et de Physique^ torn, xlvii. p. 98,
gives the following as the composition of camphoric acid :

Carbon 56«29

Hydrogen 6*89

Oxygen 36-82

which indicates the formula C40 H15 O10. — Journal de Pharmacie,
Feb. 1837.

GIGANTIC CARP.

In the Proceedings of the Zoological Society for Nov. 8, 1836,
inserted in our number for June last, (Lond. and Edinb. Phil. Mag.,
vol. x. p. 481.) is recorded the exhibition of a Carp weighing 22
pounds, which had been taken in a piece of water called the Mere,
near Payne's Hill, in Surrey. It is also stated that " Mr. Yarrell ob-
served, that he could find no record of any Carp so large having be-
fore been taken in this country." On this account the following notice
which I have just now accidentally met with may be worth citing.

In the "Historical Chronicle" of the Gentleman's Magazine for
September, 1771, (vol. xli. p. 424?), it is related, under the head of
Monday, [Sept.] 30, that " A carp, weighing 23 pounds, was lately
caught in a pond belonging to Sir John Filmour [Filmer], at East
Sutton, in Kent." This Carp seems to have been the largest speci-
men on record j for Mr. Yarrell, in his History of British Fishes,
(vol. i. p. 309,) notices a brace weighing 35 pounds, and two single
fish weighing 18 and 19^ pounds respectively, as the largest which
he could then refer to.

The above, like most of the relations in that department of the
Gentleman's Magazine, is probably newspaper intelligence. The
circumstance does not appear to be mentioned in either edition of
Hasted's History of Kent. ^ XXJ n

July 21, 1837. E.W.B.

CURTIS's ENTOMOLOGY.

We have the pleasure of announcing the appearance of the
Second edition of Mr. Curtis's Guide to an Arrangement of British
Insects. It is printed on the novel plan of the former edition, con-
tains several hundreds of new species and genera, and has the ad-
vantage of an Alphabetical Index of the latter. We need scarcely
add that this Guide is indispensable to all Entomologists.

METEOROLOGICAL OBSERVATIONS FOR JUNE 1837.

Chiswick. — June I. Slight rain: showery: clear and fine. 2. Overcast

and fine. 8. Hazy. 4. Fine. 5. Very fine : rain at night. 6, 7. Very
fine. 8. Dry haze. 9. Fine: heavy rain. 10. Cloudy: showery.

] 1. Rain : very fine. 12. Slight rain. 13. Very fine. 14. Showery.
15 — 17. Very fine. 18. Rain : fine. 19 — 26. Very fine. 27. Dry

haze : fine: clear and cold. 28. Cloudy; fine. 29. Very dry. 30. Fine :
clear and cold at night.

Boston. — June 1. Fine. 2, 3. Cloudy. 4. Fine. 5. Fine : rain with
thunder and lightning p.m. 6. Cloudy. 7, 8. Fine. 9. Fine : rain p.m.
10. Cloudy: rain p.m. 11, 12. Fine : rain p.m. 13. Fine. 14. Cloudy:
rain early a.m. 15. Fine. 16. Fine: rain p.m. 17. Fine. 18. Rain:
rain early a.m.: rain p.m. 19. Cloudy. 20. Cloudy: rain p.m.

21 —27. Fine. 28. Cloudy. 29, 30. Fine.

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THE

LONDON and EDINBURGH

PHILOSOPHICAL MAGAZINE

AND

JOURNAL OF SCIENCE.

♦

[THIRD SERIES.]

SEPTEMBER 1837.

XXV. Experiments made during a Voyage, and at Bermuda,
on the Carbonic Acid in the Atmosphere. By Lieut.-Col.
Emmett. Communicated by John Dalton, D. C. L., fyc.

Notes on Carbonic Acid in the Atmosphere in a Voyage to
Bermuda.

1836, April 28.

Lat.46°0'

Long. 14° 51

29.

— 44 7

18 21

May 1.

— 42 58

23 8

3.

— 42 9

— - 27 55

11.

— 39 39

37 4

13.

— 39 8

38 6

25.

— 30 53

61 9

Carbonic acid found in all these trials made. Lime-water
was the test. The quantity apparently fluctuated, the film
forming at times more rapidly than at other times ; most, ap-
parently, at the 29th of April and the 1st of May.

Experiments made at Bermuda, per quantity.
Experiment I . Sept. 25th. A glass receiver of 3920 cubic
inches, = 15*5 gallons, was taken to the north side of the
island beyond any building. Wind north ; day fine ; thermo-
meter 79°. Into this, after well washing with rain water and
collecting the air, were put 1500 grain measures of lime-water.
The receiver was then well closed with a cork, and set aside.

Sept. 24, 4^ p.m. ; therm. 82°. Some of the lime-water
used was tested: 1500 lime-water taking 410 test sulphuric
acid, the liquid would be 1*009 test. It took 330 to saturate

Third Serifs. Vol.11. No. 67. Sept. 1837. 2G

226 Lieut.-Col. Emmettcw the Carbonic Acid in the Atmosphere.

the remaining lime-water; consequently left 80 for the carbonic
acid in the air*.

Experiment 2. 25th of Sept. Receiver and acid as before,
but the lime-waters but 210 for neutralization. Wind strong
from S. W. ; thermometer 80°.

Sept. 28th. The lime-waters from the receivers took 120
grain measures for neutralization, leaving 90 for carbonic
acid gas ; a very nearly similar result as before.

Experiment 3. Oct. 2nd, at 5 p.m. ; wind S. W. at the
cessation of a heavy gale, with much rain ; therm. 78°, barom.
30*00.

Receiver and acid as before. Lime-water required 390 mea-
sures for neutralization. Tested that in receivers at 5 p.m. of
the 8th inst. ; therm. 75°. This required 210 measures of
the acid for neutralization, leaving 180 for carbonic acid, being
double that before, or about 1 in 3920.

Experiment 4. Oct. 11th, 4J p.m. Collected air as be-
fore. There had been much rain during the day, but it was
fine and calm after 3 p.m. Therm. 77°^. In this case the
lime-water took 375 measures for neutralization.

Tested that in the receivers on the 18th ; therm. 75°. The
1500 grains in the receiver required 280 grains for neutrali-
zation, leaving 95 for carbonic acid gas.

In the experiments 1, 2, and 4, the gas is consequently about
1 in 8000 ; and in the 3rd, 2 parts in 8000. In the 3rd, the
receiver was out during the rain, but so placed as to prevent
its entrance. The air in 2 and 4 had traversed the small island
of St. Davids, distant perhaps \\ of a mile, thinly in habited,
and thence the inlet of the sea, St. George's Harbour.

The acid was pure, brought out with me for particular ex-
periments.

Looking to the general result, and in No. 3 the quantity
being double, inaccuracy of observation of the measures might
possibly have led to the differences.

[Probably the whole terraqueous globe is enveloped with
the same atmosphere, as is the case in azotic and oxygenous
gases. The reason why the carbonic acid is not so obvious,
is its extreme minuteness. The whole quantity is not more
than j-qjs-q th part of the mass, or TJ^ part of the volume of
the atmosphere. I have examined the air in a hothouse in
July, with the air pent up during the night, and open in the

* The receiver was not long enough exposed : my bottle was two gal-
lons ; it was exposed three or four days, and agitated to exhaust the air.
Consequently ten times as much would probably be required by ten timet
the size of the bottle.

Prof. Dove's Outlines of a general Theory of the Winds. 227

usual manner during the day, and the whole quantity is the
same as the carbonic acid in the atmosphere, neither more
nor less.
August 9, 1837. J» D]

XXVI. On the Influence of the Rotation of the Earth on the
Currents of its Atmosphere ; being Outlines of a general Theory
of the Winds. By Prof H. W. Dove of Berlin *
[With a Plate.]
"VTOT one of the philosophers who have attempted to give
-^ a theory of the winds, has gone beyond the discussion
of the regular phaenomena between the tropics ; for which,
indeed, they cannot be blamed, as it is right in a very compli-
cated investigation to examine the most simple case first.
But, on the other hand, it must seem strange that since 1685,
(in which year Halley published his theory of the trade-winds,
consequently for 150 years), not a step has been made to-
wards a general solution of the question. The purpose of this
treatise is to show, that the phaenomena of the trade-winds,
those of the monsoons, and the complicated relations of the
winds of the temperate and frigid zones are necessary and
simple consequences of the same fundamental physical causes.

The velocity of rotation of the single points of the surface
of the earth is in proportion to the semidiameter of the parallel
circles under which they lie ; it therefore increases from the
poles, where it is zero, to the equator, where it is greatest. In
the state of rest the air partakes of the velocity of rotation of
the place over which it is. If, therefore, from the difference
of temperature, or from any other cause, it receives an impulse
to flow in a parallel circle, the rotation of the earth will not
have any influence upon it, because the points of the sur-
face at which the current of air arrives, have exactly the same
velocity of rotation as the points whence it has proceeded.
But if air is by any cause propelled from the pole towards the
equator, then it comes from places whose celerity of rotation
is small, to places at which it is greater. The air, consequently,
then turns with less celerity to the east than the places with
which it comes in contact; it therefore seems to flow in an op-
posite direction, viz. from east to west. The deviation of the
wind from its original direction will be the greater, the more
the velocity of rotation of the point of starting, by an equal
progressive motion, differs from the velocity of rotation of the
place at which the wind is observed, viz. the greater the dif-
ference of geographical latitude of both places. Hence fol-
lows:

* From Pogscndorff's Annalen, vol. xxxvi. p. 321.
2G2

228 Prof. Dove's Outlines of a general Theory of the Winds.

1. In the northern hemisphere, winds which begin as north
winds, in gradually advancing pass through NE., and become
more and more easterly.

Supposing places, A Ay A/; A//;
B B, B„ B„.
C C, C„ Clu

so situated, that of A, B, C, D, being under the same meridian,
the place A is the most northern and D the most southern ;
of A A/ A,i A,„ situated under the same parallel, A is the most
western, A//; the most eastern ; and that the whole bulk of air
contained between A A,„ and D D//y from any cause is put in
motion from north to south; then, if the air which had proceeded
from C C/; arrives nearly as a north wind in the parallel DD///5
that coming from B B/// will arrive quite as a north-east wind,
while that arriving from A Au/ will appear still more as an
easterly wind. To an observer who is in D Dt/I the vane will
thus have gradually turned from north through north-east to
east.

2. In the southern hemisphere, winds that begin as south
winds, in gradually advancing pass through south-east and
become more and more easterly.

If, therefore, ^ ^ ^ ^

° °\ *", £

b b b b
a a a a

designate places of which those being under the parallel a a/t/
are the most southerly, and those in the parallel d dM are the
most northerly, an observer being in d djn will see the vane turn
gradually from S. through SE. to E.

If in this manner an easterly wind shall have arisen in the
northern or southern hemisphere, it will pass through the
parallels D Dw and d d/f/ without being at all modified by the
rotation of the earth.

If the cause which drove the air to the equator continues,
the east wind, which is the consequence, will check the current.
The current being thus checked, the air will soon acquire
the velocity of rotation of the place beneath ; it will join it in
a state of relative rest. With a continual tendency to stream
towards the equator, exactly the same phenomena will be re-
peated which we have just examined.

Let us now suppose that the equatorial currents appear after
the polar currents have prevailed for a while. In the northern
hemisphere a rising south wind will take the place of the
polar current, grown more or less easterly by shifting from

Prof. Dove's Outlines of a general Theory of the Winds, 229

E. through SE. to S.; in the southern, the equatorial current,
appearing as a north wind, will change the polar current,
grown more or less easterly from E. through NE. to N.

In the parallel D Dw of the northern hemisphere, the va-
riation hitherto observed will consequently be upon the whole :

N. NE. E. SE. S.;

in the parallel d dM of the southern hemisphere, on the con-
trary, exactly the opposite :

S. SE. E. NE. N.

Air which flows from the equator towards the poles comes
from places having greater velocity of rotation to places
which move more slowly towards east. Hence follows :

3. In the northern hemisphere a southerly wind in gra-
dually advancing passes through SW. and becomes more and
more westerly.

4. In the southern hemisphere a northerly wind in gra-
dually advancing passes through NW. and becomes more and
more westerly.

If D D, D„ D,„

E E, E„ E,„

F F, F„ K,
G G, G„ G,„

designate places of the northern hemisphere, of which those
in the parallel G (3r are the most southerly, and if the whole
bulk of air contained between D D//7 and G G//y is put in mo-
tion from south to north, an observer being in D D7//, though
he will receive the air coming from E % nearly as south, will
feel that which proceeds from F F//7 more as SW., and that
from G G/y/ more as west.

If in the same way, g g, g„g,„
J J j J //J ///

d d d d
/ // ///

designate places of the southern hemisphere, ggM being the
most northerly, and dc^the most southerly, and if the air
between both parallels is put in motion towards the south
pole, an observer being in d dtn, though he will receive the air
from e e as north, will observe, that from ffM more as NW,,
that from g gttt more as W.

A westerly wind in both hemispheres will have a retarding
influence upon new equatorial currents and fix them to relative
calm. The tendency towards the pole continuing, the phe-
nomena will always be repeated till new polar currents change

230 Prof. Dove's Outlines of a general Theory of the Winds.

the westerly wind in the northern hemisphere through NW.
to N., in the southern through SW. to S. Hence the varia-
tion will be

for the northern hemisphere, S. SW. W. NW. N.
for the southern hemisphere, ~\ -wr ;njw w ow q

on the contrary J

From the whole of the phenomena observed, the following,
consequently, is the result :

A. In the northern hemisphere the wind turns, if polar

currents and equatorial currents take place alternately,
upon an average in a direction S. W. N. E. S. through
the points of the compass, and it springs back between
S. and W. and between N. and E. more frequently
than between W. and N. and between E. and S.

B. In the southern hemisphere the wind turns, if polar cur-

rents and equatorial currents take place alternately,
upon an average in a direction S. E. N. W. S. through
the points of the compass, and springs back between
N. and W. and between S. and E. more frequently
than between W. and S. and between E. and N.
Hence follows :

a. Where in the tropical zone only polar currents prevail

on the surface, there is no complete rotation, but an
unchanged deviation proportional to the distance of the
place of observation from the outward limits of the
current, which is only modified a little by the variation
of that limit in the seasons. These are the trade-winds.

b. Where in the tropical zone, by the peculiar distribution

of the solid and fluid, a southerly current alternates once
a year with a northerly one, there is only one rotation
in the whole year. These are the monsoons.

c. In the temperate, and probably also in the frigid zones,

where equatorial currents continually alternate with
polar currents, the wind changes upon an equal average
and more frequently in a fixed direction through the
points of the compass, but in the northern hemisphere
exactly in an opposite direction to that in the southern.
This is the phenomenon which I have denominated the
law of rotation.
It is evident then that the relations of the tropical winds
are the most simple case of the law of rotation.

The preceding discussion does not depend on the origin
of the motion of the mass of air contained between the observed
parallels, whether we suppose it to be contemporaneous in all
points of the same meridian, or successive, by suction or

Prof. Dove's Outlines of a general Theory of the Winds. 231

propulsion. It is also quite immaterial whether the currents
arising in the north or the south are opposed to each other,
or whether they are more or less beneath one another, and
inclined towards the meridian. For that very reason 1 con-
sider the names northerly and southerly currents to be the
most conformable to nature, as making their names independ-
ent of the variations which the seasons and local causes may
produce in their direction.

The trade-winds and monsoons are a phenomenon so mani-
fest, that it is not necessary to prove their existence. It is
otherwise with the law of rotation.

When in the year 1827 I endeavoured to prove the ex-
istence of this law by the calculation of 14,600 observations of
the barometer, as many of the hygrometer, and 21,900 of the
thermometer, which could not be added as mean quantities al-
ready determined, but were to be computed one by one, I did not
presume that it would be objected to the result of so laborious
an investigation, that of three seamen who had been questioned,
one should know nothing of it. The possibility that this could
happen, proves more distinctly than the silence of the physical
manuals upon it, that philosophers did not acknowledge a
law in the variations of the direction of the wind. If, how-
ever, we consider the remarkable regularity with which this
law is manifested in the variations of the barometer, thermo-
meter, and hygrometer in Paris and London, calculated by
me not only upon a yearly average, but even in every single
month, as well as its perfect independence of the daily period, —
results which were confirmed by the interesting memoir of
M. Galle relative to Danzig, — we might indeed expect, from
the exactness of earlier observers, that at least the direct per-
ception of that regularity did not escape them. In a review
of older and later writings I have also found many proofs of
this perception, but which always remained unnoticed for want
of a strict proof. This proof, however, could only be given
by passing from the computation of the averages to the com-
putation of the mean variations. But the rule generally ac-
knowledged as just, that we must commence from the average
in the investigation of atmospheric phenomena, has unfor-
tunately been understood to mean that we must not go beyond
the average in these investigations.

While I have recourse to direct observations in order to
prove the general validity of the law of rotation, I premise,
that I myself consider this proof imperfect. The calculation
of the observations of the barometer at a single place in
North America, and in the interior of Russia, worked out as
I have done for Paris and London, would be a more con-

232 Prof. Dove's Outlines of a general Theory of the Winds.

vincing proof than a number of the best authorities. But for
years I have in vain endeavoured to procure journals of ob-
servations that might be applicable. The same is the case
with regard to the southern hemisphere. But the accordance in
the description of the phenomenon for nearly two centuries
and a half, I believe, speaks for their correctness; nor is it
likely that men of different nations and states, as Bacon, Ma-
riotte, Sturm, Forster, Le Gentil, Don Ulloa, Toaldo, Poitevin,
Romme, should have copied one another in noticing the same
observation, particularly if we consider that in the works of
Muschenbroek, Nollet, Sauri, and Saussure nothing is to be
found upon it ; nay, that Deluc and Cotte, who occasionally
quote Mariotte's observation, omit it in the facts for which
they vouch.

I. Southern and Northern Hemisphere.

Law of rotation in the northern : S. W. N. E. S.
southern : S. E. N. W. S.

1. I am indebted to the kindness of Captain Wendt, who
sailed round the world several times as commander of the
Prussian ship Princess Louise, in answer to an inquiry ad-
dressed to him, for the following notice :

" The wind in the southern hemisphere usually turns from
north through west to south and south-east. Its direction
consequently is contrary to that of the wind in the northern
hemisphere. To the best of my knowledge the fact is nearly
as follows : Near the Cape of Good Hope in summer, the
wind is chiefly SE. but if the wind turns northerly, it is then
more violent. When the best summer months are at an end,
after a calm of short duration the wind usually blows very
moderately from SE., with an unusually clear sky. The
wind is continually increasing, whenever it turns easterly; and
if it has turned to the north, clouds and lightning are sure
to appear on the western horizon, and in less than half an hour
a storm from WNW. will ensue, and will not cease until,
after 24? or 48 hours, it has veered more to the south."

" Near Cape Horn, both to the E. and W., with a north
wind there is generally good weather ; when it veers to the
NW. it soon blows hard; with a WNW. to SW. it usually
blows a storm (which is also frequently the case from WNW.
and NW.). The wind subsides as it becomes southerly.
SSE. fine weather, frequently succeeded by a calm."

2. JEthiopic Sea.—(Le Gentil)*. " On the 25th and 26th we
experienced a kind of gust {coup de vent) from north to south-
west by west, and I remarked a fact which you have had oppor-

* Voyage dans let Mers de VInde, ii. p. 701 ; Lettre a M. de la Kux.

Prof. Dove's Outlines of a general Iheory of the Winds. 233

tunity of observing more frequently than myself, that the winds
do not follow the same rule in this hemisphere as in the north-
ern hemisphere; in this they make the circuit of the compass
from north to north-east, to east, to south-east, to south, &c. :
in the southern hemisphere, on the contrary, they move in an
opposite direction; the hurricanes, the tempests and the gusts
appear to me to be subject to this same law in both hemi-
spheres. Physicists have hitherto given no explanation of
this phenomenon."

3. Pacific Ocean. — (Don Ulloa)*. " The wind in the South
Pacific Ocean is never fixed in the NE., nor does it ever
change from thence to the E. ; its constant variation being to
the W. or SW., contrary to what is seen in the northern
hemisphere. In both the change of the wind usually corre-
sponds with the course of the sun ; hence, as with us, it changes
from E. to S., and thence to W.: there it is from E. to N. and
thence to W."

4. South Sea.— (Forster)f. " Between 40° and 60° south
latitude, in the year 1773, we quite unexpectedly met with
easterly winds, which were very contrary to our course at the
time. It was also remarkable that every time the wind changed,
which was the case four times between June 5th and July 5th,
it gradually moved round half the compass in a direction con-
trary to the course of the sun." I believe I may understand
Forster to have borrowed this expression in the way usual
among navigators from the course of the sun in the northern
hemisphere.

It would be very desirable to find remarks on this subject
with regard to the southern hemisphere in the works of Basil
Hall. I have looked for them in vain.

To these authorities I add, that all the descriptions I am ac-
quainted with of storms in the southern hemisphere, give a
rotation corresponding to the above.

II. Northern Hemisphere.

1. England^ 1600. (Bacon's Draught for the Particular
History of the Wind. Sect. xii. Philosophical Works, by
Shaw. Lond. 1733. 4to. vol. iii. p. 476.)

" When the wind changes conformably to the motion of
the sun; that is, from east to south; from south to west; from
west to north ; and from north to east ; it seldom goes back ;
or if it does 'tis only for a short time : but if it moves in a
contrary direction ; viz. from east to north ; from north to
west; from west to south ; and from south to east; it generally

• Voyage to South America, vol. i. p. 8. ch. 3.
t Bemerkungcn, S. 111.

Third Series. Vol. 11. No. 67. Sept. 1837. 2 H

234- Prof. Dove's Outlines of a general Theory of the Winds.

returns to the former point, at least before it has gone through
the whole circle.

u If the south wind begins to blow for two or three days,
the north wind will sometimes blow suddenly after it : but if
the north wind blows for the same number of days; the south
wind will not rise till after the east has blown a while."

2. France, about 1700. (Mariotte on the Nature of Air,
p. 160.)

" When the north and north-east winds cease, the east ge-
nerally succeeds, and then follow the south and south-west
winds. The south and south-west winds generally succeed
the east in the temperate zones, and especially in France. In
France the winds pass from east to south and to south-west,
then to the west, to the north and north-east, and very seldom
make an entire circuit in a contrary direction."

3. Germany, 1722. (Sturm, Physica elect iva sive hypothe-
tical torn. ii. p. 1206.)

i( Non vagatur tamen sine omni regula irregularis etiam
haec flatuum aereorum variabilitas. Ex multis enim retro
annis, et his ipsis, quibus haec scribimus, diebus, noviter ob-
servavimus, esse quandam illorum periodicam circulationem,
ita ut occidentalem excipiat ut plurimum ac ordinarie septen-
trionalis, hunc sequatur gradatim orientalis, deinceps auster
in occidentalem iterum paulatim determinetur; non neglectis
equidem plagis intermediis, et raro admodum in contrarium
verso hoc ordine, vix unquam saltern (si forte ab occidente in
meridiem flectatur) ultra orientis terminos excurrente, tantum
abest, ut plenum retrogradationis circulum facile absolvat;
cum alterum ilium directionis frequentissime, saepius uno
mense pluries, decurrat : adeo ut haec una videatur inde re-
perta nobis via, qua citra multae artis subsidium, futuras aeris
mutationes, in proximos saltern dies, praesciri, et absque fre-
quenti errore praedici queant: id quod multiplici experimento
compertum habemus."

4. Italy, 1774. (Toaldo on Meteorology applied to Agri-
culture, p. 62.)

" In fact, if there be no obstacle, the winds go the round of
the horizon with the sun."

5. Southern France. (Poitevin on the Climate of Mont-
pellier, p. 65.)

" When the winds have blown from the south and south-
east with violence and brought rain with them, they run
through the south-west and west points of the compass, and
terminate with north-west, which brings back fine weather.

" The north and north-east winds often pass over the east
and are succeeded by sea-winds (SSE.). It is very seldom
that the north winds veer directly to north-west; however

Prof. Dove's Outlines of a general Theory of the Winds. 235

this sometimes takes place; in general they traverse the horizon
passing by the east."

6. Northern Temperate Zone of the Atlantic Ocean. (Romme's
Tables of Winds, Tides, and Currents, vol. i. p. 56.)

" According to an English captain of an East Indiaman, the
dominant winds from the parallel of 30° N. to the frigid
zone are in this sea from the west or WSW. He re-
marked that a great north or north-west wind which ends
with a calm is followed by a south wind, which brings rain,
and which acquiring much force ranges to the west and
NW. or N. If these latter winds become violent they turn
sometimes to NE. and blow for several days together, or end
in a calm to be followed by a south wind. If this latter is
rather westerly it is accompanied with rainy weather and
squalls, and often comes back to the south with rain."

7. Freiberg in Saxony, 1806. (Lampadius's Systematical
Manual of Atmospherology, page 189.)

" How exceedingly changeable are the winds in Germany !
yet I have remarked a kind of periodical movement in them,
which is as follows. I suppose the wind to blow from the south,
with a clear sky. The barometer falls, the weather becomes
thick, rain follows. In the mean time the wind becomes
westerly. The rain still continues, and the barometer rises.
The wind changes to the NW. Partial rain ensues. It grows
colder. The barometer still rises, and the wind becomes N.
and NE. The barometer is now at the highest point, the sky
is serene, and the severest cold possible in the season prevails.
The wind veers to the E. and the barometer falls a little,
but the weather as yet remains clear. The wTind veers to the
SE., the barometer still falls, the warmth increases again.
The wind then changes to the S., and the warmth reaches the
highest degree agreeable to the season ; the barometer falls,
and we come back again to the first point. There are annually
several such periods in every season. Sometimes it will take
several weeks to complete this rotation of the wind through the
whole compass, sometimes but a few days. The wind will
very rarely change in a direction contrary to that above men-
tioned. In general all changes from the left to the right of
the horizon are more frequent with us, and a southerly wind
is the least frequent. There certainly exists a primary cause
of this, which is, however, concealed by many casualties."

Lampadius has however gone beyond this excellent descrip-
tion of the phenomenon. As Sturm had done before him, he
has founded meteoromantic rules upon the supposed correct-
ness of this law, and in his "Contributions to Atmospherology"
has examined to what degree they may be depended upon.

2 H 2

236 Prof. Dove's Outlines of a general TJieory of the Winds.

8. East Prussia, 1826. The following is the result of my
own observations made at Koenigsberg. (PoggendorfTs^wa/.,
vol. xi.)

I have observed rotations in the direction of S. W. N. E. S.
at all seasons, but they appear most frequent during the win-
ter. If a SW. wind blows with increasing violence, and
finally prevails, it raises the temperature above the freezing
point, therefore it cannot snow, but it rains, while the baro-
meter arrives at its lowest state. The wind now turns towards
the W., and the thick flakes of snow prove the beginning of a
colder wind, as well as the quickly rising barometer, the
vane, and the thermometer. If the wind is northerly the sky
grows serene, and if NE. the maximum of cold and of the
barometer takes place. This however gradually begins to fall,
and fine cirri show by the direction of the fibres at their origin,
the southern wind which had set in, and which the barometer
already indicates, even while the vane feels nothing of it and
still points steadily to the east. The southerly wind however
with gradually increasing force drives the east wind in a down-
ward direction; simultaneously with a decided falling of the
quicksilver the vane indicates SE., the heavens become gradu-
ally more and more covered, and with increasing heat the snow
is converted by SE. and S. by SW. again into rain. There
is now a recommencement, and the driving downwards on the
eastern side is in a highly characteristical manner separated
from that on the west side by a clearing up for a short time.
Once acquainted with the phenomenon, when it appeared in its
most evident form it was easy for me again to recognise it in
its more irregular changes; nay, to deduce these, and also a
frequent springing backward, particularly on the western side.
Hence, therefore, I ascertained that, in this country at least,
all winds are great whirlwinds (I have seen rotations of from
one to twenty two days) ; that the rotation within side this
whirl moves on an average always in the same direction.

9. Germany, Gunzenhausen. Although the rotation has
not been definitely described here, it will, however, easily be
recognised in the following extracts. Luz* says the N. and
NW. winds raise the barometer, and one might almost say,
invariably. The E. and NE. also frequently do this; not,
however, with so much certainty. At the same time there is
a clear sky. With W. wind the barometer also rises, but
the sky is then covered with lofty scattered clouds, which,
however, seldom rain. With SE. wind the barometer falls,
and the weather, notwithstanding, remains settled so long as

* Beschreibung von Barometern, 1784, p. 351.

Prof. Dove's Outlines of a general Tlieory of the Winds, 237

the wind does not veer towards the south. With regard to
S. and SW. winds no such definite rules can be given. In
genera], the barometer falls when the wind comes from this
quarter. If, however, it has continued for some time in this
direction, and especially if it has rained for some time, the
barometer again rises, although the wind continues to blow
from S. and SW. I also found the barometer to fall with a
N. and E. wind, if the wind came for some time from this
quarter, and the clear weather would change into dull and
rainy.

10. Holland. This subject has been examined by Van
Swinden* more completely than by Luz. Horsleyf was the
first to demonstrate in a more definite manner the influence
already pointed out by Halley and Mariotte, of the direction
of the wind upon the state of the barometer, by calculations
made from a table showing the heights of the barometer for
every prevalent wind. The attention of Van Swinden being
excited by this, he proposed to himself the question, How
often does the barometer fall with a certain wind, how often
does it rise with the same? The results of his calculation are
a necessary consequence of the law of rotation. He finds in
the year 1779, that the barometer

With

Rose

Fell

SW.

74 times.

83-9 times.

w.

36 —

16-6 —

NW.

83 —

43*5 —

N.

12 —

9*3 —

NE.

24 —

28* —

E.

1 —

8*3 —

SE.

18 —

51-8 —

S.

10 —

15-5 —

In the three preceding years, he had obtained with regard
to W., NW., N., and E., SE., S., results coinciding with
the above ; but, on the contrary, deviations with regard to
NE. and S W. These solstitial points then appear here quite
as definite as those of Luz. It does not appear from any ex-
pression of Van Swinden that he was acquainted with the law
of rotation ; and it is on that account that Saussure, in his
Hygrometriey asks, " Why do the east winds, although cold
and dry, generally cause the barometer to fall in England and

* Memoires sur les Observations Meteorologiquesfaites a FrancJcer en Frise
pendant 1779.

f An abridged state of the weather at London in the year 1774. Phil.
Trans, for 1775.

238 Prof. Dove's Outlines of a general Theory of the Winds.

in Holland, according to the observations of Horsley* and
Van Swinden, while the west winds commonly cause it to rise ?
No hypothesis with which I am acquainted gives a satisfactory
reason."

11. Denmark. During 1100 changes of the direction of
the wind observed in Apenrade by Dr. Neuberf, 559 were
in the direction of S., W., N., E., S.; 457 in the contrary.

12. Sweden. " In order to examine how far these changes
(namely those motions of the barometer calculated by me in
Paris, from the law of rotation for hydrometeors,) take place
in other countries during rain. I have," says Dr. Kamtz %,
" brought together in a similar manner the calculations of Ni-
cander in Stockholm. Of three observations out of nineteen,
made between 2 and 9 o'clock, I have taken as a basis for the
comparison the wind which blew about 2 o'clock. The fol-
lowing table contains the magnitudes found, in Parisian lines :

Day before the Rain.

Rainy Day.

w.

+ 0-13

+ 0-22

NW.

+ 0-31

+ 1-06

N.

+ 0-42

+ 0-60

NE.

4-0-6

4-0-44

E.

-o-oi

-0-41

SE.

-0-50

-065

S.

—0-41

-0-61

sw.

—0-71

—0-27

"On the day before and during the rain, the barometer sinks
with easterly, rises with westerly winds, just as Dove has de-
duced from observations in Paris."

13. North America. In the State of Missouri, the wind in
constant repetition traverses within from ten to twenty days
every quarter of the horizon, and always in the following order,
going from E. through S. to W., and through N. toward E.
Duden^, who makes this remark, adds that he never had ob-
served a completely opposite course.

14. Germant/. Schiibler|| says: " The rotation of the winds

* In regard to Horsley, Saussure is in error : he had only calculated the
averages, but not examined the rise and fall.

-f- Collectanea Meteorologica sub auspiciis Societatis Scientianwi Danica?
edita. 1829.

X Meteor., vol. ii. p. 365.

§ Voyage to the Western States of America, p. 200.

|| Fundamental Positions of Meteorology principally relating to Ger-
many. 1831. p. 28.

New Method of solving Equations of partial Differentials. 239

takes place in Germany more frequently in the order of S.
through SW,, W., NW, N., NE., E., and SE., than in the
opposite order of S. through SE., E., NE., &c."
[To be continued.]

XXVII. A new Method of solving Equations of partial Dif-
ferentials. By S. S. Greatheed, Esq., B.A., of Trinity
College, Cambridge.*

SEPARATION of the symbols of operation from those of
quantity, has, as far as I know, been hitherto applied only
to the calculus of finite differences, and to the differential
calculus where both are involved. It appears to me that if
any much greater eminence than that to which analysis has
already been brought, remains to be attained by it, that
process is the most obvious and likely path. The following
pages will show how, by applying it, a large class of partial
differential equations, including nearly all that occur in ap-
plied mathematics, may be reduced to differential equations
of two variables.

The following known theorem is one which will be con-
stantly made use of.

The expression e dx f(x) is equivalent to Taylor's series
forf(x + h).

I shall begin with the equation of the first order and degree
with constant coefficients :

dz . dz

a — + b -y- = c.
dx dy

d z
If instead of -7— we had nz, n being a constant, the

equation would become

dz , ,
a-r- + nbz — c,
dx

a linear equation between x and 2, which may be solved by

nbx

multiplying by the integrating factor 1 « , whence

d nbx c nix

--—lea z) = — e a
dx\ ) a

nbx nbx

therefore * « * = J3 * ° + c >

c - nb*

z = —r + e a r-

n o

* Communicated by the Author.

240 Mr. Greatheed's ?iew Method of

My method, then, for solving the proposed partial differ-
ential equation is this : Substitute -7— for n9 or let n repre-
sent -7-, and proceed exactly as in the above solution of the

equation between two variables, substituting for the arbitrary
constant an arbitrary function of y. The result then will be

^ \ — 1 -bx d

+ e d-ayf{ay).

_ 4 (A)

b \dy)

d

■bx

By the proposition which was premised, s d'ay f {a y)
is equivalent to f (a y— b x). Also, since integration is the re-
verse operation to differentiation, / — — J is equivalent to
f dy = y. Hence, finally,

* = C~f + f(ay-bx)9

which is the correct solution of the proposed equation. I shall
proceed to explain the meaning, and prove the legitimacy, of
the several steps in the solution.

bx d

In the first place, multiplying by the factor s a dy * is
equivalent to changing all functions of y to which it is prefixed

bx

into the same functions of it -\ • Now % is an unknown

r a

function of x and y, suppose it equal to $ (#,3/), then

bx d j 7 b x d j <

-— d z b — ■—- a z

S a dy — — -U — g a dy _- —

d x a ay

is equivalent to

d f bx~\ b d f bx \

— | \x9y + -j + - -^{x9y + _ j,

which is the total differential coefficient of f < x9 y H I

with respect to x.

As for the other side of the equation, namely,

bx d
g a dy . _

a

bs d

•The more proper expression would be "prefixing the symbol e a d»'\
but since it is convenient, and the operations are exactly analogous, I shall
use the term u multiplying."

solving Equations of partial Differentials. 24 1

d.
effect, and

c
since — does not contain y, the symbol prefixed to it has no

bx _d_

a ' a '
But the integrals of these two expressions with respect to x
are not the same. This may be explained by writing instead

c d cy — —

°^ ~a9 ~d~~ ' ~a9 w^cn> Dv prefixing e « dy % js changed

t? * cQ+t)_ j <yt#

Hence the equation

t . 6 g d b x d

(e a dy Z ) = f «
/

is the same as

da? * V'^ + a J- - -j^ b

(the first side representing the total differential coefficient with
respect to z). By integration,

$

r ; bx \ c(y+ir) . *', x

Finally, by multiplying both sides of the equation by

— bx d

s a dy 9 that jSj changing functions of y into functions of

*-— '

4> (x,y), or2 = -2 +/(fl|y_fta!:).

Hence it may be seen that the essential part of the method
consists in making each member of a partial differential equa-
tion a total differential coefficient with respect to one of the
variables.

The most general class of equations of the first order, which
can (as far as I am at present aware) be solved by this method,
are those which fall under the form

Third Series. Vol. 11. No. 67. Sept. 1837. 2 I

242 Mr. Greatheed's new Method of

where X is a function of x only, Y of y only, and P and Q
are functions of both x and y. This may easily be reduced
to the form

dz v dz ^ ^

-=- + X -v- = P* -f Q,
dx dy

for

if v' = / -=^ , Y -yr = -7-7. I shall then consider the

y J Y cty rfy

latter equation.

Let it be put under the form

g+(x4-p)_Q)

and treated as a linear equation between two variables z and x,

/(xA-p)dx x' ^- -/Pdx
The integrating factor ise dy = e dv . s ,

supposing yX d x = X'. The effect of the first part of the

X'— .
factor, namely, e dy is, as has before, been stated, to change

functions of y into functions of z/+X', and it affects, not only

d z

-= — and z9 but also the other part of the integrating factor,
a x

namely, s~fFdx9 provided P contain y; therefore?/ in P
must be changed into y + X7 before the integration is per-
formed, and afterwards, y is to be restored.
The equation will then stand :

= e *» t J Q.

The first side is the total differential coefficient of e ~~fPdxz
(y + X7 being substituted for y) with respect to x ; and the
second side is the similar differential coefficient of some un-
known function of x and y. It would require the solution of
the original equation to exhibit this function, but this diffi-
culty is avoided by integrating the expression on the second
side by the common rules. It remains to integrate both sides
with respect to x, add an arbitrary function of y, divide both

x'~ . -fPdx

sides by § dy (that is, change y into y —X') and by s ,

and then the value of z is obtained.

I shall adjoin a few examples, but previously I shall prove

the following curious theorem, which is of use in several.

solving Equations of partial Differentials. 243

1 vm

- . vm *■ — —

a 4- t»,
rflog^
where a is any constant.

Let y = e', then d . log y =z dt, and

1 1

,mi

a ± j~i ^ + -7T

— a log j/ —a/

1 . _ 1 dsmt 1 d?*" -

771

+ —5- +
a3

.nit

a -£ m a + 77j

From this it may be shown that if y, y\ y'\ &c. be any
number of independent variables, and b9 b\ b'\ &c. constants,

_ _ — irw"*

dlogy dlogy' dlogi/'

ytn y'mf y\\m"

a + mb + mf b' + m" b" +

„ .• dz t dz
Example 1. jt-j Hy-^ — = n%.

d X \ a; d log # x /

The integrating factor is

, d , i d

f 6 dlogy 6 __ x g * dlogy#

Multiply by this factor, and integrate, therefore,

x-n .k* "TO * = <p (y) = <> (8l0gy )
d

and * = xn « " l0g * «^sy $ (i 1<>8y )

* , logy -log a?
as X $ (s )

= x Ha;/

2l2

244 Mr. Greatheed's new Method of

T? i^ dz y dz x ,

Example 2. -=— = ^- —. 1 ,

r dx x dy y

■n .,. dx y dz x

By transposition —, -^ — y— = — ,

J r dx x dy y

d z Id x

or -j -jr: z = — .

dx x d log y y

i d

-log rr-

The integrating factor is e diogy ; Multiplying by

it, and integrating,

d „ d

dlogy z = / g~10Sxdlogy^ ^

logx

-/£

dl°gy d-r

y
a

y

^Q"m"d~T^u 1 . ^/>sy

dlogy

Divide by ■ " 0ga?dloS3/ or * <*log?,

a:2 -1 log*-r/— A/ loS3\

therefore 2= -5 — .3/ + « 6 diogy $ (e ).

2— a
diogy

By the theorem above,

-1
1 -1 y

: — —y = 3 •

dlogj/

Consequently a = h <p (xy).

6y

^ 1 ^ dz , dz

Example 3. ?/ -^ + •*" -g^- = 2,

dz ( x d 1 \

dx \y dy y )

d* (a d A\

The integrating factor is

tJ\ d.rf y * -. g d.ytt& J y %

or

solving Equations of partial Differentials. 245

The effect of the first part of the factor on the second is to
change it into

x+s/x2+y*

= /*?.-!

x+y

■*-i- i

Multiplying therefore by f rf-3^ -, and integrating,

By the same principles the equation

dx dy x+y
may be integrated.

The method is equally applicable to equations of four or
more variables, of which I shall take a single example.

Example 4.

dz dz dz xy

u— \- x—j 1- y -7 — = a z H — .

du dx J dy u

dz 1 / d d \ xy

du u \d log x dlogy J u2

/ d d \ d d a

Multiply by e °gU d loS * + dlogy ~ ">'_. udloSx^d\ogy 9

and integrate, therefore

^ d d C d d _

g °g M \dlo~g~x+ d logy ~~a)z — Cu d log x + d logy ° Xy Ju

d d

dlogz + dlogy"0--1 logx logy

= W—-j 3 ## + <*>(* ».■ )

a a

c? log # d log 3/

—l

rf log # d log y

246 New Method of solving Equations of partial Differentials,
-f if <p (e log* ~log M , s logy ~log M )

There are several equations which are not of a form to
which this method is immediately applicable, but which be-
come so by a slight transformation. For instance, in the
equation

d x dy w

where X, Y, Z are functions of x, y, and z, respectively,
assume

d z

/dz

and it becomes

X

dz'
dx +

dz'

dy

•

In the equation

X

dz
~dJ +

dz

= 0

make x the depend'

ent variable, then

dx

dz
dx

1
: dx »

dz
dy

dy

dx

d z

dz

and the equation becomes

dx

VT7

dx
dy

- + x = 0

which may be solved in the same manner as Example 3.
The equation

/ . \ dz , . v dz

may be transformed so that this method shall be applicable,
by taking x+y = w, and x and u for the independent varia-
bles. It then becomes

dz _ dz

u -j 2x -3 — = %.

dx du

As this article has already been extended to some length,
I shall defer to a succeeding Number the application of my
method to equations of the second and higher orders. It is
in those chiefly that it claims a superiority to the method of
Lagrange ; and in cases to which his does not apply it gives,

Memoranda on the Origin of the Botanical Alliances, 247

very readily, an abbreviated expression for the series, in which
the solutions may be exhibited, but which would often be
hard to determine by indirect methods.
Trin. Coll., Camb., July 20, 1837. S. S. GREATHEED.

XXVIII. Memoranda on the Origin of the Botanical Alliances.
By Sir Edw. Ff. Bromhead, Bart., MA., F.B.S. L. $ E*

\ GARDH mentions Batsch as the first writer who at-
■**■ tempted to form alliances on a sound principle, though
unsuccessfully; and Dr. Lindley justly notices " Agardhii
opera gestumatissima Bartlingiique, qui viam ad meliores res
aperuere." Agardh's work and a selection of others, which
I in vain endeavoured to procure from the Continent, Dr.
Lindley most kindly forwarded to me from his own library.
By this I have been enabled to institute a comparison with the
alliances proposed by botanists of every school, a test very
useful in confirming sound assemblages, ascertaining their
true limits, and developing the ground of their formation.
Such a reference is moreover a necessary act of justice to the
founders.

Usneales. — These are the Bhizophyta or Sporidiacea? of
Rudolphi: "Sporangia spuria vel nulla, sporidia substantias vel
superficiei immersa, cotyledonidia nulla." Linnaeus doubted
whether the Fungi should form part of the series in an arrange-
ment of plants. They have been made sufficiently numerous
to form one or more distinct alliances ; some have represented
them as passing into Lichens, others as passing into Alga?.

Usneos^e are nearly the Sporidiferce of Agardh, and the
Fungales of Dr. Lindley.

Jungermanniales. — These are the Musci (hepatici and
frondosi) of Hedwig, who omits Riccia. They are the Foliacece
of De Candolle, the Musci of Bartling, and the Muscales of
Dr. Lindley.

JuNGERMANNios#: are nearly Dr. Lindley's second section
of Acrogens.

Lycopodiales. — The Tetradidymce of Wahlenbergh, found-
ed u quaternata dispositione sporarum," add to this alliance
Ophioglossaceae, and doubtfully Equisetaceae. Agardh ex-
cluded the latter; Dr. Lindley excluded also the former from
his Lycopodales. Lepidodendrum is now added : there can-
not be any reason why extinct genera should be overlooked in
botany more than in other branches of natural history. All

* Communicated by the Author.

24-8 Sir Edw. Ff. Bromhead's Memoranda

the great transitions in nature are through small families, in
which the structure seems to want breadth, or what mechani-
cians would call stable equilibrium. A series of monographs
of the families and tribes, which are limited to a few species,
would be an important acquisition to science.

Lycopodios^ correspond with Dr. Lindley's first section
of Acrogens.

Cupressales. — These are the original Coniferce of Lin-
naeus, if we exclude Ephedra and Liquidambar.

CuPRESSOSiE. — These are nearly the Lepidanthce aceroscc
of Shultz; or the Gymnosperms of Dr. Lindley's System.
Horaninow, an acute Russian naturalist, includes the Lyco-
podial and Osmundal unions with Lichens under the name
of Sporopkora? : " Synorrhizis sporae conglutinantur ad embry-
onem producendum, ipsis innatum."

Betulales. — These are nearly the Amentacea: of Linnaeus,
who however placed Liquidambar among Coniferae, and
added to this alliance Myricaceae, Platanaceae, and Pistacia*
Herman notices this form of inflorescence under the name of
Julifera?.

Betulos^s. — This formation perhaps more accurately re-
presents the Amentacece of Linnaeus. The Lepidanthce foliosce
of Shultz nearly coincide. The Micranthce of Agardh indi-
cate a property important in this part of the system.

Rhamnales. — The Rhamnales of Dr. Lindley consist of
Rhamnaceae, Chailletiaceae, Tremandraceae, Nitrariaceae, Bur-
seraceae. Reichenbach includes several Rhamnales among
his Variflorce Parviflora.

Euphorbiales. — The Tricoccce of Bartling are Stack-
houseae, Euphorbiaceae, Empetreae, Bruniaceae, Rhamneae,
Aquifoliaceae (Brexia), Pittosporeae, Celastrinae, Hippocra-
teaceae, Staphyleaceae. The Euphorbiales of Dr. Lindley are
Euphorbiaceae, Empetraceae, Stackhousiaceae, Fouquieraceae,
Celastraceae (Hippocrateae), Staphyleaceae, Malpighiaceae
( Ery throxyleae). The Discigyna? Trihilatce of Agardh con-
tain many unarranged Rhamnales, Euphorbiales, and iEscu-
lales: calyx basi monophyllus, stamina definita discigena,
carpellis subconnatis subternis.

JEsculales. — The Malpighince of Bartling are Malpighi-
aceae, Acerineae, Coriarieae, Ery throxyleae, Sapindaceae, Hip-
pocastaneae, Rhizoboleae, Tropaeoleae. The calycose struc-
ture of the Nixus appears here.

Hypertcales. — The Guttales of Dr. Lindley's Calycosce
are Clusiaceae (Canelleae), Rhizobolaceae, Marcgraaviaceae,
Hypericaceae, Ochranthaceae.

Limoniales. — The Meliales of Lindley are Meliaceae,

on the Origin of the Botanical Alliances, 249

Cedrelaceae, Humiriaceaa, Aurantiaceae, Spondiaceae. The
Aurantiiflora of Reichenbach embrace several unarranged
Hypericales and Limoniales, to which he adds Linaceae and
Leeaceae. The " Carpophyta, Thalamanthece " of Rudolphi
embrace unarranged the families from Hippocrateae to Li-
moniaceae, both inclusive, to which he adds Ampelideae, Dil-
leniaceae, Magnoliaceae, and Anonaceae.

Fabales. — The Lcgumina of Ca3salpinus,or the Leguminoses
of Morison and Ray, must be considered the basis of this al-
liance; but they separated the herbaceous and woody plants.
Royen united them.

Fabosje. — The Calophtfta of Bartling include, among others,
Rosales and Leguminosae ; Dr. Lindley unites these under
his Rosales with Connaraceae and Calycanthaceae.

Violales. — The Violales of Dr. Lindley, are Violaceae
(Sauvagesiae), Samydaceae, Moringaceae, Droseraceae, Fran-
keniaceae. — Decandolle used the parietal structure as a means
of classification. Dr. Lindley improved upon Agardh's Val-
vispora?, and introduced the true distinctions.

Passiflorales. — The Passionales of Dr. Lindley contain
Passifloraceae, Papayacea?, Flacourtiaceae, Pangiaceae, Ma-
lesherbiaceae, Turneracese.

Passifloros^e. — The Peponiferce of Bartling are Samydeae,
Homalineae, Passifloreae, Turneraceae, Loaseae, Cucurbitaceae,
Grossularieae, Nopaleae.

Portulacales. — The Succulenta? of Agardh are Melocac-
taceae, Crassulaceae, Mesembryanthaceae, Portulacaceaa.

Eljeagnales. — The Proteince of Bartling are Laurinese,
Santalaceae, Elaeagneae, Thymelaeae, Proteaceae. Dr. Lindley
brought Penaeaceae into this neighbourhood. They are part
of the miscellaneous Rigidifolia? of Reichenbach.

Acanthoses. — The true Monopetalce begin here ; they seem
to have been founded by Ray. Bartling's grouping of them
is masterly, though the interior arrangements are not satis-
factory.

Lamiales. — These are the Labiates of Dr. Lindley. Dr.
Brown formed Verbenacece-JLamiacecB into a class. Arnott
unites Selaginacese-Myoporaceae-Verbenaceae.

LAMioSiE. — These are theDiscigyn&Monopetalce of Agardh,
who adds Pedaliaceae: "fructu subtetraspermo ; caryopses, vel
capsula tetrasperma disco affixa." They are the Nucamentosce
of Dr. Lindley.

Rhinanthales. — These are the Scrophularinece of Dr.
Brown, if we add Orobanchaceae, and omit Digitaleae, &c.
The Labiatiflora? of Bartling embrace unarranged the whole
Lamial union, if we add Oleaceae and Jasminaceae, and if

Third Series. Vol. 11. No. 67. Sept. 1837. 2 K

250 Sir Edw. Ff. Bromhead's Memoranda

we omit Verbasceae-Digitaleae. The Personate of Dr. Lind-
ley's Nixus took the same range.

Ericales. — These are the Ericinece of Richard andBartling ;
the Ericales of the Nixus. They are part of Agardh' s mis-
cellaneous Aridifolitf : " folia coriacea, calyx saepe coriaceus."

Campanulales. — These are nearly the Campanulacece of
Jussieu and Richard. They are the Campanulacea of Agardh.

Cynarales. — The Subaggregatce of Agardh include Cam-
panulales and Cynarales, but he omits Plantaginaceae, and
adds Nyctaginaceae with the tribe Staticineae. The Aggre-
gosce of Dr. Lindley are Calyceraceae, Compositae, Dipsaceae,
Valerian aceae, Brunoniaceae, Plantaginaceae, Globulariaceae,
Salvadoraceae, PI umbagin aceae.

Myrsinales. — These are the Primulales of Dr. Lindley, if
we add Brexiaceae and Pittosporaceae : he places Brexiaceae
near them, and mentions the affinity. The Sapotacece of
Reichenbach contain Oleinae, Styraceae (Humiria),Trientaleae,
Myrsineae, Olacinae (?Millingtonia), Asterantheae, Aqui-
foliaceae (Brexia), Mimusopeae.

Rutales. — These are the Rutacece of Ad. de Jussieu, if
we add Ochnaceae. The Discigynce Polypetala? Gynobasece of
Agardh are Rutales with Geraniaceae, the other Geraniales
being scattered in three or four classes : "Stamina disco inserta,
stylus saepe in Gynobasin dilatatus, carpella quina, saepe libera
vel apice lobata, subconnata." They are the Rutales of Dr.
Lindley. They form the first six families of Bartling's Tere-
binthince ; he relies much on the double pericarp here and
elsewhere in the Usneaceous or woody race.

RuTOSiE. — These are the Gynobaseosce of Dr. Lindley, who
adds Coriariaceae.

Malvales. — Dr. Brown must be considered the founder
of this alliance ; he first brought into notice the valvate aesti-
vation. The Columniferae of Agardh are Chlenaceae, Tiliaceae
(Elaeocarpeae), Buttneriaceae, Bombaceae, Malvaceae: "sta-
minibus stylo adpressis, inaequalibus ; styli plures, saepe coa-
liti ; folia lobata." The Malvales of Dr. Lindley are Stercu-
liaceae, Malvaceae, Elaeocarpaceae, Dipteraceae, Tiliaceae,
Lythraceae.

Laurales. — These are nearly the Lauri of Jussieu. The
Laureales of Dr. Lindley are Lauraceae, Illigeraceae, Cassy-
thaceae.

Magnoliales. — The whole of the Magnoliales stood to-
gether in Dr. Lindley's first edition of his " Natural Sy-
stem." He has noticed the woody habit in this neighbourhood ;
his Anonales are Myristicaceae, Magnoliaceae, Anonaceae,
Schizandreae, Dilleniaceae.

on the Origin of the Botanical Alliances. 251

Magnoliosje. — This formation perhaps gives the correct
limits of Dr. Lindley's important Albuminosa?.

MenispermosjE. — Linnaeus was obviously acquainted with
both the transitions to the Monocotyledons.

Asp arag ales. — The Pkylloacroblasta? Liliacex of Reich-
enbach are Juncaceae {Junceae, Triglochinae, Melantheae,
(Scheuchzeria, Butomus)}, Sarmentaceae { Xeroteae, Smilaceae,
DioscoreaB}, Coronariae {Methoniceae (Alstromeria), Tuli-
paceae, Gilliesieae, Scilieae, Hemerocallideae, Alliaceae, Dra-
caeneae}. Dr. Lindley has very happily disentangled the Li-
liaceae.

Asparagos.se. — The Endogenous alliances begin here ; Cses-
alpinus vaguely marked them " Triplici principio fibrosae et
buibosae;" Ray must, it seems, be deemed the founder of the
Monocotyledons as a class, though Lobel noticed the struc-
ture.

Bromeliales. — Richard unites the Hypocarpous Endo-
gens (nearly Orchidales and Bromeliales) under the name of
Monosymphysogonie, loosely arranged; he mentions as an
objection, that Hydrocharaceae would so be separated from
Alismaceae. Hess, a botanist of admirable tact, adopts
Richard's arrangement, which is also more or less recognised
by Dr. Lindley. — Agardh makes some Rhizanths stand next
Hymenomycetes ; if they all lie together, they may well form
a distinct alliance.

Ulvales. — These are nearly the Algce.

Charales. — The Goniopterides of Bartling contain Cha*
raceae and Equisetaceae. It may be doubted whether the
shell of Sigillaria can be considered as bark.

Osmundales. — These seem to be nearly the Capillares of
Morison and Ray. Dr. Lindley has judiciously broken them
down into natural families.

Piperales. — The Piperina? of Bartling include Chloran-
thaceae, Piperaceae, Saururaceae. In his first edition of the
" Natural System," Dr. Lindley threw together after the
Chenopodiales the following families: Saurureae, Chloran-
theae, Lacistemeae, Piperaceae, Podostemeae, Callitrichineae,
Ceratophylleae. This led directly to the Haloragales, and
suggested the transition from the Urticales, on which the
arrangement of the Ulvaceous race is founded.

Haloragales. — The Haloragea? of Bartling contain as
sections Hippuridea, Callitrichea, Halorageae (Trapa).

CEnotherales. — The Calyciflorce of Bartling contain his
Halorageae, Lythrarieae (Elatinacefle), Onagrariae (Philadel-

2 K2

252 Sir Edw. Ff. Bromhead's Memoranda

pheae), Rhizophoreae, Vochysieae, Combretaceae, embracing
nearly both alliances.

Myrtales. — The Myrtina? of Bartling are Memecyleae,
Melastomaceae, Myrtaceee (Lecythidaceae, excl. Punica).

Rosales. — These are the Rosacea; of Jussieu, with the ad-
dition of some later discoveries.

Saxifragales. — The Saxifragacea? of De Candolle include
Saxifrageae, Hydrangeaceae, Cunoniaceae, Baueraceae, Escal-
loniaceae. The Corniculata of Reichenbach contain Cras-
sulaceae (? Cephalotus, ? Francoa), Saxifrageae {Genuinae
(Adoxa), Cunoniaceae (Bauera, Hydrangea), PhiJadelpheae},
Bruniaceae. His Ribesiaceae contain Cacteae, Grossularieae,
Escallonieae (Aristotelia).

Cucurbitales. — These are the last four families of Bart-
ling's Peponifera, with the addition of Begoniacese, the affi-
nity of which he hints at. The Cucurbitales of Dr. Lindley
are Cucurbitaceae, Loasaceae, Cactaceae, Homaliaceae; he
places Begoniaceae near them.

Chenopodiales. — The Oleracea? of Agardh contain Che-
nopodeae (excl. Galenia, Salvadora, Theligonum), Rivineae,
Phytolacceae(Miltus),Amaranthaceae, § Illecebreae, Petivereae,
Polygoneae. The Curvembryosa? of Dr. Lindley are Amaran-
taceae, Chenopodiaceae, Tetragoniaceae, Phytolaccaceae, Poly-
gonaceae, Petiveriaceae, Scleranthaceae, Nyctaginaceae, Meni-
spermaceae. The families of the Portulacales and Chenopo-
diales require to be recast; Bartling has effected much in
his Caryophyllina?.

Bor agin ales. — These are nearly the Asperifolia? of Ray.
Linnaeus noticed the circinate inflorescence. The Tubiflora
of Bartling constitute unarranged the Boraginal union, if we
add Plumbaginaceae and Verbasceae-Digitaleae, and if we
omit Retziaceae.

Gentianales. — These are the Gentiana of Jussieu, if we
add Retziaceae.

Apocynales. — These are nearly the Contorti of Linnaeus.
The Contorts of Bartling embrace the Gentianales and Apo-
cynales, if we add Retziaceae, and omit Lygodysodeaceae.

Galiales. — The llubiacina? of Bartling are Lygodyso-
deaceae, Rubiaceae (Stellatae), Caprifoliaceae, Viburneae.

Cornales. — The Cornales of Dr. Lindley are Hamame-
laceae (Fothergilleae), Cornaceae, Loranthaceae.

Geraniales. — The Geraniacea? of St. Hilaire and Richard
are Oxalideae, Tropaeoleae, Balsamineae, Linaceae, Geranieae.
The Geraniales of Dr. Lindley are Geraniaceae, Balsaminaceas
(Tropaeoleae), Oxalidaceae ; he mentions the affinity of Suria-

on the Origin of the Botanical Alliances. 253

naceae and Limnanthaceae, and places them also among Gy-
nobaseosa*.

Cistales.— The Cistales of Dr. Lindley are Elatinaceae,
Linaceae, Hugoniaceae, Chlenaceae, Cistaceae, Reaumuri-
aceae.

Brassicales. — This alliance was established by Dr. Brown,
Resedaceae being here removed, and Tremandraceae being
added. Bartling's Rhceada: are Tremandreae, Polygaleae,
Resedaceae, Fumariaceae, Papaveraceae, Cruciferae, Cappari-
deae; stress being laid upon the intervalvular placentation.
The miscellaneous Brevistylce of Agardh include Brassicales,
Polygalaceae, &c, but without Tremandraceae: "fractious so-
litariis brevistylis, stigmate suborbiculato ; stylus o vel brevis
et quasi acumen germinis ; stigma orbiculatum, et peltatum
vel capitatum."

Nymph^ales. — The Bandies of Dr. Lindley are Ranun-
culaceae (Podophylleae), Papaveraceae (Fumarieae), Nym-
phaeaceae (Hydropeltideae), Nelumbiaceae, Cephalotaceae
(Dionaea).

Avenales. — The Glumacece of Reichenbach are Gramineae5
Cyperoideae, Commelinaceae {Restioneae (Lilaea), Xyrideae
(Aphyllanthes, some Liliaceae), Philydrinae, Xyphidieae (Fla-
gellaria), Pontedereae, Commelineae}. The Glumosce of Dr.
Lindley take nearly the same range.

Typhales. — The Spadicosce of Dr. Lindley are Panda-
naceae, Cyclanthaceae, Araceae, Acoraceae, Typhaceae, Naia-
daceae, Juncaginaceae, Pistiaceae.

July 13, 1837.

In a note upon Sir E. Ffrench Bromhead's former paper, inserted in our last
volume, pp. 48, 137, the agreement of some of the principles of arrangement ad-
vocated by the author with those enunciated by Mr. Win. S. Macleay was briefly
pointed out. It may tend to preserve the interest now taken in the subject, if
some further points of coincidence between the views of classification which have
arisen in the mind of one naturalist from the investigation of the animal kingdom,
and those which have been presented to that of another from the investigation of
the vegetable kingdom, be also noticed. It is observed in the preceding paper,
under the head ' Lycopooiales,' p. 247 — 8, that " All the'great transitions in na-
ture are through small families, in which the structure seems to want breadth,
or what mechanicians would call stable equilibrium." Taking " families" to mean,
merely, in this place, comparatively smaller groups than those which they are the
means of uniting, the passage here cited is an accurate statement of the nature
and characters of what have been termed by Mr. Macleay, Osculant groups. The
want of " breadth," or " stable equilibrium " in their structure, is the consequence
of their being the means of transition from one type to another, and uniting,
therefore, in themselves, the structures of the groups which they thus connect.
In the animal series, as Mr, Macleay has remarked, the osculant groups which
unite the primary divisions are, comparatively, very imperfect beings j the result,
doubtless, of the blending in them of the structure* belonging to two distinct
types.— E. W. B.

XXIX. Account of some Experiments made in different Parts of
reference to the Effect of Height. By James D. Forbes,

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Third Series. Vol. 11. No. 67. Sept. 1837.

258 Professor Forbes's Experiments on

§ 4. On the Direction of the Isodynamic Lines {for horizontal
Intensity) in the Central Alps, and in the Pyrenees ; and on
the Iiifluence of Height.

25. The next question comes to be how to deduce the ge-
neral results contained in the preceding tables. Where it is
merely required to deduce the position of isodynamic lines
(which may be considered as sensibly straight for a district of
moderate extent), projection of the results upon paper would
afford quite a sufficient approximation, where the stations are
sufficiently multiplied. Thus the variations in latitude and
longitude would be determined, and lines of intensity 1*00,
1-01, 1*02, &c. might be drawn with great accuracy upon a
geographical map.

26. But the same process will not suffice, if we have a third
variable, such as height, and require to extract its influence.
The problem, then, is not to draw lines, but planes of equal
intensity. For its solution I resolved to use the method of
least squares*, which is peculiarly applicable to a question of
the kind just stated, and may be made to give, as will imme-
diately be seen, the most probable value of the four following
quantities, viz. the variation of intensity for 1' of latitude; its
variation for lf of longitude; its variation for J00 feet of ele-
vation; its most probable absolute value at the origin of the
coordinates, or the station to which the others are referred.

27. I assumed that the intensity of any point whose coor-
dinates of latitude, longitude, and height, might be denoted
with sufficient accuracy by an expression of the form

ax + by + c z = 1 (1.)

a, b9 and c indicating the position of the point by reference to
the three coordinates, whilst x, y, and s denote the coefficients
of variation of intensity according to each of these, and which
are to be discovered. The above expression being the equa-
tion to a plane, denotes that the isodynamic lines are not con-
sidered as curved, but as straight, which though not absolutely
accurate, may be admitted in a country of small extent.
•28. Eq. (1) gives the intensity I in terms of a, b, and c, the

• It would be absurd to claim any merit for the application of a method
so universally known. But lest I should be supposed to have borrowed
without acknowledgement the method of reduction employed by Professor
Lloyd and Captain Sabine in their excellent Magnetic Survey of Ireland
(Fifth Report of the British Association), I desire to state, that I had some
years ago proposed to myself the present method of reduction as the only
one adapted finally to solve (within the present limits of error) the question
of the influence of height, which so greatly complicates the problem.

Terrestrial Magnetic Intensity. 259

coordinates of the place ; a being reckoned in minutes of lati-
tude, b in minutes of longitude, c in hundreds of feet of eleva-
tion. It is convenient to assume some station as a point of
reference, and write for a, b9 and c, the differences of the co-
ordinates merely, and for I the difference of intensities. Let
a'9 b\ c\ and I' represent these quantities for the fundamental
station, and then for any other the expression will be

(a-a')x + (p-V)y + (c-c') z = I-I'

and by a combination of all the equations of similar form
which the observations furnish, we are to deduce the most
probable values of x9y, and z, the coefficients of variation in
each direction. If, further, we wish to have the most probable
absolute value of the horizontal intensity at the fundamental
station before mentioned, it must clearly be deduced from the
whole mass of the observations, and not from the observation
made there alone. Let us suppose, then, that the intensity at
the fundamental station requires a small correction, 8 I', we
shall write I' + flF instead of I' in the preceding expression,
considering 8 Y as another unknown quantity, which will give
us a series of equations (for the different points of observation)
of the form

(a-a')j? +- (b-V)y+ (c-c) z = I-I'-*I' (2.)

or using the letters with subscript numerals instead of a — a\
&c, and putting all the unknowns on the left hand, we shall
have a series of equations of condition of the form

a\x + hy + ciz + 8I' = Ii 1/q >

a * + b2y + c*» + 81' = I2 J W

&c.

from which the most probable values of x, y, z, and 8T are to

be deduced by the method of least squares.

29. The observations contained in Table VII. include two
groups of observations, to which we mean to apply the me-
thod in question. One of these includes the alpine observa-
tions made in August, September, and October 1832; the
other a short series in the Pyrenees, made almost entirely
with reference to the effect of height in 1 835. The remaining
observations must be considered for the present as isolated.
They are important, however, as fixing the relative horizontal
intensities at Paris, Edinburgh, Brussels, Heidelberg, and
some points of less note. The admirable coincidence of the
Edinburgh observations made in different years gives great
confidence in the accuracy of the determination of '8402 for
the horizontal intensity, that at Paris being = 1 ; both needles

2 L2

260 Prof. Forbes on Terrestrial Magnetic Intensity.

fiving the same mean result to four decimal places. Professor
lansteen has given *8428, which must be considered as a
close coincidence.*

For Brussels I find by "No. I." 0-960

by "Flat," 0*965

Captain Sabine 0*951

M. Quetelet (4 series) 0*964

M. Rudberg 0*971

I subjoin a few comparisons of stations common to M. Que-
telet's seriest and mine.

Quetelet. Forbes, No. 1.

Castle of Heidelberg 1*020 \

Town of do 1*024 J I'° '

Konigstuhl (summit) 1*027 1*018

Geneva 1*080 1*076

Chamouni 1*093 1*085

St. Bernard 1*097 1*082

Martigny 1*092 l*08'i

[To be continued.]

XXX. On a New Rain Gauge. By the Rev. Thomas Knox,

M.R.LA.%

[With a Figure : Plate II.]
f~\ N the 26th of June last, a new rain-gauge was exhibited
r*7 to the Royal Irish Academy, contrived by the Rev. Tho-
mas Knox.

The object of this instrument is to register the amount of
rain that falls when the wind is in different points. Its con-
struction is very simple. The water, — instead of descending
from the reservoir directly into the tube of registry, — passes
through a lateral tube into an annular-shaped vessel, divided
into eight compartments, each of which terminates below in a
graduated glass tube. It is obvious, then, that if the eight
tubes be set to correspond with the cardinal and intermediate
points, and that the reservoir be made to revolve on a vertical
axis by means of a vane, the direction of which corresponds
with that of the lateral tube, the object proposed will be attain-
ed. Mr. Knox has preferred to make the reservoir fixed, and
the system of tubes moveable ; but the result is obviously the
same.

* Since this paper was read, this result has been still more nearly con-
firmed by the observations of Professor Bache of Philadelphia, who, by
connecting Edinburgh and Dublin, and taking Professor Lloyd and Captain
Sabine's observations for the comparative intensities at Dublin and Paris,
has obtained the number *8400.

f See his two papers in the Me moires de V Academie de Bruxelles, tome
iv. ; and an abstract in the Annuaire de V Observatoire de Bruxelles, 1834.

% From the Proceedings of the Royal Irish Academy, No. 5.

londSc-Idut. FTiiZ. Mag. VolTLTLTL

TTieFev. JHFJTnax's Rain Guage

Scales- of Recent & Fossil- Satmum

^fn^

[ 261 ]

XXXI. On the Crystalline Form of Pyrosmalite: hitherto
undescribed. By H.J. Brooke, Esq., F.R.S., fyc*

1LTAVING in my possession a specimen of this mineral
-*--"- with well-formed crystals resembling the annexed figure,
and having measured them with the reflective goniometer, I
am enabled to supply a description of their form, which has
not yet, that I am aware of, been given.

Assuming, for the sake of simplicity, the regular hexagonal
prism as the primary form, and that the
planes b result from a decrement by one

row corresponding to B, the ratio of a
terminal eilge to a lateral edge will be
found as 15 to 16 nearly, and the planes

a will correspond to the symbol B.

The angular measurements are as fol-
lows:

Pon a = 148° 30'
b as 129 13
M m 90
MonM' = 120 H.J. B.

XXXII. Papers on the alleged Periodical Meteors of the 1 3th
of November, and on Shooting Stars in general. By M.M.
Wartmann and Quetelet.

I. Notice respecting the Periodic Meteors of the 1 31 h of
November. By M. L. F. Wartmann f.

A COSMOLOGICAL phenomenon of the most interest-
-£** ing kind, although new as yet in the records of science,
is at present attracting the attention of astronomers, meteor-
ologists, and physicists. The magnificent assemblage of lumi-
nous points and globes which has been seen for several years
presents a highly important subject of inquiry, by which we
may be enabled to add to the stock of our knowledge respect-
ing the constitution of our planetary system.

The appeal made upon this occasion by M. Arago spread
far and wide, and this very year [1836] numerous observations,
made in different places, have been sent to the illustrious philo-
sopher who had asked for them. They concur in showing that,
towards a point of the heavens at a small distance from the
stars /3 and y in the constellation Leo, a considerable quantity
of shooting stars seem to be produced, and to succeed one

* Communicated by the Author.

t From the Bibliotheque Univcrsclle, N. S. 2 de Ann. No. 18, June 1837:
having been read before the Society of Physics and Natural History of
Geneva, Dec. 15, 1830.

262 On the alleged Periodical Meteors and on Shooting Stars,

another at short intervals, precisely in the place where a pro-
digious number of them had already been seen at Geneva in
1832, and especially in the United States in 1633. What is
the nature of these fugitive stars ? Whence do they come?
Whither do they go when they disappear from our sight ? Do
they sometimes fall upon the earth ? Such are the principal
questions which every one asks himself, and which are of the
highest interest.

The much-wished-for fall of one of these meteors would
without doubt furnish the chemist and physicist with the means
of explaining certain points quite unknown. Those observers
also, who were aware of the importance of this inquiry, have
not neglected to bestow their attention in this direction, and
some of them, in fact, state that they have seen several of these
meteors which were projected against the sides of the mountains
by which they were surrounded. This fact is undoubtedly of a
positive nature, but is it such as to prove the authenticity of the
fall of the meteor down to the surface of the earth ?^.Have not
the illusions which exercise so great an influence here, and un-
der which observers are more or less placed, contributed to a
belief in a projection towards the ground which was apparent
only ? In support of this suspicion I may be allowed to mention
a fact which I had an opportunity of stating more than six years
ago in the former series of the Journal of Geneva, in the numbers
for March and April, 1830, as follows : A meteor appeared
on the 19th of March of the before-mentioned year, at half-
past seven in the evening ; according to the report of eye-wit-
nesses, it had a round disc, with a well-defined edge, which
was almost equal to that of the full moon, and which shed a
strong light of a bluish colour ; it circulated with great velo-
city from east to west, and appeared to be at a very great
height. Those who observed it at Geneva, and who followed
it with their eyes in its horizontal course, thought they saw it
burst in the air, and fall in pieces at some paces before them.
Other persons, living at the village of Chene, half a league
from Geneva, and who were by chance in the street, being
convinced that they had seen it fall on a neighbouring house,
ran directly to ascertain whether the building had not been set
on fire. This same meteor was also remarked at Saint-Legier,
near Vevey, in the canton of Vaud, and on the heights of
Fraubrunnen in the canton of Berne. Those who saw it from
this last place, and who followed it for about thirty seconds,
agree in saying that it travelled slowly in the direction of the
Jura, and that it appeared to them to fall not far from the
neighbourhood of Orbe, a small town of the canton of Vaud,
thirteen leagues north-east of Geneva. Thus in the three si-
tuations, the illusion of the observers was so complete, that in

M. Wartmann on the Periodical Meteors of Nov. 13. 263

spite of the distance which separated them, namely, in the one
case a half league and in the other more than thirteen leagues,
they each thought they saw the meteor fall down near them.
Such a fact evidently shows that this fall is by no means real,
and that if the meteor seemed to descend towards the horizon,
this circumstance without doubt is owing to the quick decrease
of the angle of sight which measured its apparent height, as
the meteor was in rapid motion away from the observers as it
pursued its horizontal course.

The appearance of this isolated meteor showed a sufficiently
remarkable resemblance to those which for some years past
have been seen periodically towards the middle of November,
to make it desirable that an opportunity should occur of veri-
fying whether there are any amongst these last which really fall
upon our globe.

The night of the 12th to the 13th of November, this year,
appeared to me proper for this interesting inquiry, from the
meteorological circumstances with which it was attended at
Geneva, and which I hastened to avail myself of. Rather thick
clouds completely veiled the heavens in a uniform manner ;
they occupied a very elevated region, where they remained
stationary all the night. The temperature was mild, the air
calm, and the darkness great, although no fog thickened the
transparency of the atmosphere.

The barometer, the thermometer, the hygrometer, the mag-
netic needle, the ethrioscope and the etectroscope were atten-
tively watched at the observatory from seven in the evening
to seven in the morning, and their progress marked with care
every quarter of an hour*. At the beginning of the observa-
tions, at seven o'clock in the evening of the 12th, the baro-
meter reduced to the zero degree marked 725mm,08, the centi-
grade thermometer in the open air + 7°#8, and Saussure's
hygrometer 87°. At midnight the first of these instruments
was at 726mm-95, the second at + 6°-9, and the third at 93°.
On the 13th, at seven in the morning, the barometer marked
729mnu30, the thermometer + 5°% and the hygrometer 98°.

To sum up, I shall say that the barometer, whose progress
was gradually ascending, rose in the space of twelve hours
of observation 4mm-22 ; that the thermometer, whose mini-
mum had been + 5°% varied in the same space of time only
2°*6; and that the hygrometer proceeded 1 1° towards humidity.
As to the ethrioscope, it did not give (as might be anticipated,

* Two of the instruments, the compass and one of the electroscopes, be-
long to the Cabinet de Physique of our Academic Museum ; these were
kindly placed at my disposal, for which my best thanks are due to the di-
rectors.

264 On the alleged Periodical Meteors and on Shooting Stars*

with a tranquil and regularly clouded sky) any sign of radia-
tion of heat across the atmosphere. The pith-ball electro-
meters, placed in the open air, remained motionless ; lastly,
the magnetic needle presented, at eleven minutes past nine, a
slight deviation of 0o,5 to the east in declination; a deviation
which remained the same till a quarter of an hour after mid-
night, after which it varied, always in the same direction, and
till tlje morning, between 0°*1 and 0°*7.

Assisted by three amateurs who wished to join me, a conti-
nued look-out was kept, not only towards the region of the
east, but in every quarter of the heavens ; the terrace of the
Observatory commanding the entire horizon.

From seven to ten o'clock in the evening a light breeze
prevailed, hardly perceptible, which blew from the north-east ;
and from ten in the evening till seven in the morning the air
remained perfectly calm, excepting at three periods, namely,
at two, at forty-five minutes past three, and at fifteen minutes
past four, when a light breeze was again perceived, and
lasted each time ten minutes.

At forty-five minutes past eight in the evening, and from
the south-south-east, a feeble white light illuminated the upper
part of the clouds for from three to four seconds. At fifty-one
minutes past nine a reddish light, resembling lightning, streak-
ed the upper part of the clouds for nearly three seconds, in
the east. At forty minutes after eleven there were white glim-
merings, very feeble, which streaked the clouds between the
north-east and the south-east ; they had a kind of intermitting,
and they lasted about six seconds. At thirty-five minutes past
one, and directly in the east, there were, in the upper region
of the clouds, some lights, in general very feeble, which conti-
nued during ten seconds. Lastly, at three minutes past four
a white light, less pale, shone for two or three seconds in the
elevated stratum of the clouds, in the south-east. But during
the whole night, not a single luminous meteor, no shooting
star, no aerolite or visible asteroid pierced the clouds to fall
in the circle of our horizon. Nevertheless, it is probable that
if the sky had not been clouded we should here have very well
seen the shooting stars which were observed at the same date
in our neighbourhood, in France and elsewhere ; and perhaps
the magnificent spectacle which the sky presented at Geneva
in the night of the 12th to the 13th of November, 1832, of
which Professor Gautier gave an account in the fifty-first vo-
lume of the Bibliotheque Universelle, might again have been
exhibited before our eyes.

The result, then, of our observations is, that the shooting
stars circulate in a much more elevated region of the sky than

M. Wartmann on the Periodical Meteors of Nov. 1 3th. 265

that attained by the clouds, and that meteors of this kind
rarely fall to the surface of the earth, if they ever do. This
opinion acquires so much more probability, as no one till
now, at least so far as I know, has been able to obtain an au-
thentic specimen of this mysterious substance.

A learned astronomer communicated to the Academy of
Sciences of Paris, in the session of the 5th of this month (De-
cember 1836) a curious and very interesting memoir, which
appears to suggest that the luminous nebulosity by which the
sun appears to be surrounded in the direction of its equator,
a nebulosity which is projected far into space, assuming the
form of a cone, and which has been known for two centu-
ries by the name of the zodiacal light, might probably be the
source of the myriads of shooting stars of the 13th of Novem-
ber, the earth at this epoch passing in the neighbourhood
of the summit of this cone. Nevertheless, the author of the
memoir, M. Biot, after having considered the subject under
different views and discussed it scientifically, ends by declaring
that he neither asserts nor rejects this identity*.

Some writers think that the origin of the shooting stars
which compose the periodical phaenomenon of the 13th of No-
vember, might also be ascribed to a great planet which may
formerly have been broken into a multitude of fragments,
which would continue to circulate one after the other in an
orbit whose position is such that the earth approaches annu-
ally very near to it on the 13th of November. These frag-
ments, endowed with a great velocity of projection, would enter
our atmosphere at this period, cross it rapidly, and, by the
friction caused by the resistance of the air, would grow so hot
there as to become incandescent and to send forth a bright
light until the moment of their quitting it.

This hypothesis, very ingenious as it may appear, is not
free from objection. Already a celebrated philosopher, whose
opinion is of great weight, has not hesitated to say that it
would be premature to attempt ascending to the physical
cause of these curious appearances until certain matters of fact
had been cleared upf; and assuredly M. Arago is right.

It is certain that in one and the same night an innume-
rable multitude of these meteors have been seen in places
whose geographical situation differs 90° in longitude and six
hours in time, a circumstance which gives to their appearance
a duration of at least 18 hours ; our night being at this period

* Comptes Rendu* de V Acad, de Paris, No. 23, December 1836, vol. iii.
p. 663.

f Ibid, p. 633.
Third Series. Vol. 1 1. No. (57. Sept. 1837. 2 M

266 On the alleged Periodical Meteors and on Shooting Stars,

more than 1 2 hours, and beginning 6 hours sooner than in
the United States.

Now as in the month of November the earth advances in
its orbit 445,500 leagues in 18 hours, a change of place during
which the appearances are incessantly succeeding one another,
it would be necessary that these meteors, if they really consti-
tute asteroids, should exist by millions in the zone where they
appear. But then these heavenly bodies, which should ap-
proach so very near to the earth, must frequently fall down
upon it, from the attractive power which the mass of our globe
would inevitably exercise on them ; and this is what has not
yet been observed.

When astronomers at the beginning of this century had suc-
cessively discovered Ceres, Pallas, Juno and Vesta, which re-
volve around the sun between Mars and Jupiter in orbits
which have not a very great eccentricity, the idea of making
asteroids originate from the fragments of a planet which might
have been destroyed by means of an internal explosion was
already put forth ; but M. Biot remarked that, with regard to
these four telescopic stars, this hypothesis is inadmissible, be-
cause, according to the theory of attraction, such an explosion
would have necessarily given to these fragments unequal ve-
locities of projection in starting from the same point, whence
great unequal axes would have resulted, which is contrary to
observation*.

It is known that Professor Brandes proved long ago, by
corresponding observations made in different places and often
repeated, that there are shooting stars which circulate with a
velocity of 1 3 leagues, of 25 to a degree, in a second, at a
height of 180 leagues above the surface of the earth f. It is
also manifest, from the observations made in the United States
compared by Professor Olmsted, that the centre from whence
the meteoric shower of the 13th of November of 1833 set out,
was elevated at a mean height of more than 800 leagues, and
consequently that it was in a region which affords no aliment
for combustion. The vivid lustre then which these meteors
exhibit, and which they could not borrow from the sun, is
their own inherent property. But as in our planetary system
we know of no celestial circulating body which shines with its
own light, this essential fact, which must necessarily be kept

* Traite Elementaire d* Astronomie Physique, 2nd edit., vol. iii. p. 42.

t These quantities, on the exactness of which we can rely, are the re-
sults of comparative observations begun in 1798 by MM. Benzenberg and
Brandos, and continued on a greater scale, in 1823, by M. Brandes and his
pupils, at Breslaw, Dresden, Leipe, Brieg, Gleiwitz, &c. — Bibl. Univ., vol.
li. p. 203; Annuaire du Bureau des Longitudes de Paris for 1836, p. 292.

M. Wartmann on the Periodical Meteors of Nov. 13th. 267

in view, sufficiently shows the propriety, I would almost say
the necessity, of considering shooting stars as a distinct class
of phenomena.

In bringing together the different data furnished by obser-
vation, and in considering the particular circumstances con-
nected with them, we may be led in some measure to conjec-
ture that the source of this singular phenomenon is, perhaps,
an electric focus, of which the determining cause is not yet
known. But we must bear in mind that, in the region of hy-
pothesis, and especially when we treat of a new subject as yet
very little studied, analogy alone, whatever verisimilitude it
may appear to possess, is not a basis sufficiently sure to found
an opinion upon. I give this idea, therefore, only as a simple
inference. It would, besides, be difficult to rank the shooting
stars, which are seen unaccompanied with noise, in the cata-
logue of aerolites, whose fall, which often happens by day, is
generally attended by a hissing in the air, by decrepitation, re-
peated detonations, and a smell more or less intense.

According to a communication made last year to the Acade-
my of Sciences of Paris*, M. Millet Daubenton observed on the
13th of November, 1835, at about nine in the evening, the
sky being serene, a luminous meteor, having the appearance
of an incandescent globe, which exploded in the air and set on
fire a barn covered with wood and thatch, near the chateau of
Lauzieres, in the department of Ain. M. Millet, according
to his own account, is the only observer who saw the immense
shower of fire that the meteor formed after bursting. This mere
chance, which gave value to his observation, induced him to
try if he could not find some stone of an unknown nature near
the house and in the surrounding fields, and, indeed, he asserts
that he picked up two of the size of a small egg. It is much
to be regretted that the Academy after having begged M.
Millet to send one of these specimens that they might ascer-
tain its nature and make an analysis of it, has as yet kept si-
lence respecting the examination of this meteoric product so
interesting by its date.

Although thirty-seven years have passed since the 12th of
November, 1799, the time when MM. Humboldt and Bon-
pland saw, at Cumana, a very unusual appearance of shooting
stars which greatly excited their attention, our stock of know-
ledge respecting the cause and nature of this majestic pheno-
menon has remained very incomplete.

Without doubt we have yet to bring together many facts,
to gather many observations, to arrange them, to discuss them,

* See the Comptes Rendus, vol. i. [>. 414.
2 M2

268 M. Quetelet on the alleged greater number

in order to obtain a definitive solution of the problem. Re-
cently, MM. Olmsted, Arago, Biot and other illustrious phi-
losophers have been occupied with this interesting subject *.
They have furnished ingenious ideas and fresh views, by which
science will profit. It is true that some diversities are ob-
servable in the hypotheses which they have advanced, but
these documents are not themselves the less to be prized and
preserved. Who knows, but that the light, to the investiga-
tion of which every one earnestly applies, may not one day
spring from the clashing of opinions ?

II. On the question whether Shooting Stars are more numerous at
certain times than at others. By M. Quetelet. t

M. Quetelet informed the Academy that during the night of the
12th of November he employed himself at the observatory of the
city in noticing the shooting stars, for the purpose of ascertaining,
whether in fact, their appearance were more frequent than at
another season. His observations presented nothing remarkable
as to the number of these meteors.

We remember that M. Arago, in giving to the Academy of Sciences
at Paris an account of the results of the numerous observations
which he had produced in support of this fact, quoted amongst other
numbers as being extraordinary, that of 170 shooting stars which
the students of astronomy in the observatory of Paris entrusted by
him with making observations, had counted during the night of the
13th of November. For appreciating this number, however, and
establishing a comparison, facts were wanting, that is to say, the
knowledge of the mean number of those meteors which may be ob-
served in a night at any other season of the year. For the purpose
of determining this number, M. Quetelet entered upon some inves-
tigations relative both to his former observations on shooting stars,
and to those of other persons, and he arrived at this result, that
the number of shooting stars which are observed, on an average,
in an hour, looking constantly towards the same quarter of the
heavens, is about eight, and that several observers, placed so as to
observe the different regions of the heavens, may count double the
number. Accordingly, the number of 170 shooting stars observed at
Paris by several persons on the night of the 12th of November would
not be at all astonishing ; on the contrary, it would come very near to

••See the article on shooting stars by Professor Olmsted in the Ame-
rican Journal of Science, or the French translation in vol. iii. of the
Compilateur, October 1836, page 52; the notices of MM. Arago and
Biot in the Comptes Rendus des Seances de I'Academie des Sciences de Paris,
vol. iii. pp. 560, 629, 663; a notice by Professor Gautier, in the Bibl. Univ.,
vol. li. p. 189, &c.

t From Vlnstitut, and originally derived from the Bulletin de VAcad.
Royale de Bruxelles,

of Shooting Stars observable at certain times. 269

the average number of these meteors which may be observed on a
winter's night.

This result of the inquiries of M. Quetelet is important enougli
for us to give it, supported by all the documents which establish it.

M. Quetelet, before making known the observations which he
recorded in 1824, with several other persons, remarks, that in ma-
king these observations his object was not to record the number of
shooting stars which may be counted in a given time, but merely to
bring together the elements necessary for calculating the height, the
velocity, and all that has relation to the path of these meteors ; it
follows, therefore, that the results which they furnish ought to be
considered as an under estimate, since many stars were not re-
corded, because the elements which should have served for their
calculation were not sufficiently exact. The same remark must also
be applied to the observations made by Benzenberg and Brandes
in 1798, the results of which will be given, as well as those made by
this last philosopher in 1823, the results of which will also be given.

The observations by Benzenberg and Brandes in 1798 were
made in the environs of Gcettingen. These two philosophers were
at first alone, and placed at a distance of 27,050 French feet apart.
But after three series of observations they felt the necessity of being
further apart, and they placed themselves at the extremities of a
base of 46,200 feet, and this time each of them took an assistant to
note down under his dictation the observations, the results of which
are brought together in the following table :

•

Shooting Stars observed by

Number of Hours.

1798.

Benzenberg.

Brandes.

Benzenberg.

Brandes.

Stpt. 11.

9

11

2h Om

2h 19m

13.

6

8

1 7

1 36

Oct. 6.

11

13

2 8

2 24

9.

14

63

2 46

8 12

14.

S3

123

7 46

7 47

Nov. 4.
Totals ..

62

49

6 34

5 35

135

267

22 21

27 53

Mean number for Benzenberg, about 6 stars an hour.

Brandes, about 10 stars an hour.
Mean number, 8 stars per hour.

The observations by Brandes in 1823 lasted two successive hours;
they were made near the time of the new moons, and during the
months of April, May, August, September, and October. The re-
sults are given in the following table :

270 M. Quetelet on the Height, Motion, and Nature

Places of Observation.

Breslaw ....

Neisse

Mirkan ....
Gleiwitz ....

Brieg

Trebnitz ....
Cracow ....

Leipe

Berlin

Brechelshof,
Dresden ...,

Shooting

Stars
observed.

650

307

65

356

144

36

43

36

7

26

40

No. of
Hours,

50

30

8

44

20

6

8

8

4

16

26

Mean No.
per Hour.

130
10-2
8-1
8*1
7-2
6-0
54
4-5
1*8
1-6
1-6

Number of the Observers.

Brandes and his assistants.
Several observers.
One observer.

Two

One

One

One

One

One

One

Two

The following are the results of the observations which M. Que-
telet made at Brussels in 1824 during ten evenings, together with
those made at Liege by MM. Van Rees, and Plateau ; and at Ghent
by MM. Morren and Manderlier :

Places.

Shooting
Stars.

Time.

Mean No.
per Hour.

155
42
51

lOh. 26m.
5 0
5 30

15*0
8-4
9-3

Ghent

After this communication of M. Quetelet, M. Sauveur stated,
that being on the road from Brussels to Liege in the night of the
8th of last August, he observed a considerable number of shooting
stars, of which several were remarkable for their size and bril-
liancy.

M. Quetelet suggests that this epoch presents a singular agree-
ment with that of the 10th of August, which the results of obser-
vations of shooting stars point out as one of those which are to be
remarked for the abundance of meteors of this kind. (See on this
subject Brandes's Untersuchen iiber die Entfernung und Bahnen der
Sternschuppen ; Leipzig, 1825; and Chladni's Feuer -meteor e, p.. 89.)

Wishing to aid in throwing more light on this interesting and yet
little known branch of meteorology the Academy has resolved to
propose for 1837 a series of observations on shooting stars.

III. On the Height, Motion, and Nature of Shooting Stars.
By M. Quetelet.*

Shooting stars, those meteors so long neglected by philosophers,
are beginning at last to engage their attention. We ask ourselves
how it happens, that whilst measuring even to the minutest circum-
stances the motion of those heavenly bodies which are at the extre-
mity of our solar system, and which, by their very distance, escape
the attention of the many, greater thought should not have been be-
stowed on a more careful examination of the nature and cause of

From the Annuaire de I ' Observatoire de Bruxelles for 1837.

of Shooting Stars.

271

the numerous appearances of these meteors, which, infinitely nearer
to us, streak every night the surface of heaven, and are sometimes
seen in such numbers that the heavenly vault would appear to re-
solve itself into a shower of stars.

Let us not, however, be in haste to suppose that nothing has been
done upon this subject. We might almost be tempted to admit that
the sciences also experience the influence and caprice of fashion,
and that a certain class of researches can only interest at a certain
epoch and under certain circumstances. Shooting stars, which had
never been the object of an investigation expressly undertaken, were
examined for the first time in a serious manner in 1798, by Benzen-
berg and Brandes, who examined them during many nights and at
many intervals, with a view to determine their mean height, their
velocity, and what belonged to the nature of their trajectory. In
1823, Brandes, seconded by a tolerable number of observers placed
in different stations, resumed the same work. At nearly the same
time (1824), I undertook, with the aid of from twelve to fifteen
persons, similar observations, which were made at Brussels, Ghent,
and Liege. I know not whether other regular observations of
the same nature have been made since. Only, at my request,
seconded by Sir John Herschel, the English scientific men assembled
at Cambridge in 1834, thought proper to propose this subject of
inquiry in the list of objects worthy to engage the attention of ob-
servers. The Royal Academy of Brussels has just come to a similar
resolution.

Now, combining the results of the observations made in Germany
and in Belgium, the following are the principal conclusions which
may be deduced from them.

1. The height at which shooting stars appear varies within very
wide limits j nevertheless the mean height may be considered as
being from 15 to 20 leagues of about 20 to a degree, that is to say,
near about the limits of our atmosphere. The two series of obser-
vations made in Germany gave :

SHOOTING STARS.

HEIGHT.

In 1798.

In 1823.

Total.

1 to 3 German Miles

3 to 6

1

2
3
6

2
2

1

4
15
22
35
13
11
3
1

1

5
17
25
41
15
13

4

1
1

q to 10

10 to 15

15 to[20

20 to 30

30 to 40

457

60

2. Shooting stars have in general a direction inclined towards the
surface of the earth. Of 36 computed trajectories, Brand6s found
26 descending ones, 9 ascending, and 1 horizontal; 13 formed an

272 M. Quetelet on Shooting Stars.

angle of less than 45° with the vertical ; 14 were between 45° and
the horizon; 8 between the horizon and 135°; and only 1 was
still more elevated. With regard to the azimuths, of 34 trajecto-
ries, 23 had a direction southwards and 11 to the north, 21 to
the west, and 1 3 to the east. Separating the shooting stars into two
groups, we find 25 of them whose course inclines more to a south-
west direction, or whose azimuth is less than 135° to the west and
45° to the east, and only 9 are in the other half portion of the hea-
vens. This difference seems to be connected with the direction of
the motion of the earth in its orbit, admitting that the meteors in
question may be considered as small asteroids.

3. The brilliancy of shooting stars is very various; these meteors
sometimes surpass Jupiter and Venus in light, and sometimes they
are only perceived by the help of finders. Some leave after them
luminous tracks visible for some seconds after their passage, which
are not to be confounded with those luminous and rapid traces
which depend upon the length of the sensation on the retina. The
trajectories appear generally as straight lines. Some of them, how-
ever, are very sensibly curved ; they are far from exhibiting a con-
tinued brilliancy in their whole extent.

4. The velocity of shooting stars has not been capable of deter-
mination with any precision, except for a very small number of these
meteors*: it is from 3 to 10 leagues a second.

5. As to the mean number of shooting stars which can be ob-
served at any given epoch of the year, after having particularly ex-
amined this question,f {Bulletin del' Acad. Royale de BruxelleSyVol.ui.
p. 404, et seq.) I have come to this result, that a single observer or
several observers directed towards one and the same region of the
heavens can see, on an average, eight shooting stars an hour, and
that several observers, placed so as to see the different regions of
the heavens, may reckon twice that number of them.

6. It would seem that a cause exists which produces, from about
the 8th to the 15th of November, more frequent appearances of shoot-
ing stars. I have also thought that I remarked a greater frequency
of these meteors in the month of August (from the 8th to the 15th).

7. As to the nature of shooting stars many doubts still remain on
this subject : are they to be considered as asteroids, according to
an hypothesis of some standing ; or as stones shot from the volcanos
of the moon, according to the opinion of Benzenberg, Chladni, and
other physicists J? I should be inclined to think that a distinction must
be made between the shooting stars which leave luminous trains
after them, persistent and often characterized by sparks, and those
whose course is marked by a trace of light as momentary as the ap-
pearance of the star, and which is only owing to the duration of the
impressions on the retina. The first appear to me to be really

* For six of these meteors whose velocity I was able to calculate, J
found 5 leagues, 7*6, 4*5, 3*0, and 3*4, mean 4*7 leagues.

t See the preceding paper. Edit.

% Die Sternschuppen sind Steine aus den Mondvul/canen, Benzenberg,
Bonn, 1834.

On the alleged periodical Meteors of November. 273

bodies foreign to our earth. The Slst July 1824, I observed an
aerolite, or luminous mass, which presented very remarkable cir-
cumstances, left sparks on its passage, and must have fallen in the
neighbourhood of Antwerp.

[The principal authorities and sources of information on the interesting
subjects of snooting stars and the alleged periodicity of certain appearances
of them, have been cited in the preceding papers of MM. Wartmann and
Quetelet ; but we may usefully add a few references in detail to the obser-
vations and researches of the physicists in the United States, who have been
the first to call attention to the apparent periodical previous appearance and
return of the brilliant shower of meteors witnessed in November, 1833.

At present, the recurrence of the shower of meteors, as it has been termed,
is asserted to have taken place about the end of the second week in No-
vember, in the years 1799, 1831, 1832, 1833, 1834, 1885, and 1836. On
the other hand, many observers deny that any remarkable or unusual phse-
nomenon of the kind was seen, except in the years 1799 and 1833, affirming
that a greater number of shooting stars was observedin the other years (espe-
cially in those subsequent to 1833), merely because the attention of ob-
servers was specially directed to them at a certain time. The following
papers and notices, among others, have appeared in late volumes of Professor
Silliman's American Journal of Science and Arts. On the Meteors of Nov.
13, 1833 ; by Prof. E. Hitchcock : vol. xxv. p. 354. On the same subject,
and on the Meteors of Nov. 13, 1834, and of Nov. 1835 ; by Prof. D. Olm-
sted: vol. xxv. p. 363; vol. xxvi. p. 132; vol. xxix. p. 168, 377; vol. xxx.
p. 370. Investigations respecting the Meteors of Nov. \3th, 1833, &c. ; by
A. C. Twining : vol. xxvi. p. 320. Papers, by Prof. A. D. Bache, denying
that any recurrence of the phenomenon took place in November, 1834 : vol.
xxviii; and vol. xxix. p. 383. An Observation in Nov. 1833; vol. xxvi.
p. 397. An Observation in Nov., 1835; vol. xxix, p. 390. Letter from the
Rev. W. B. Clarke, denying the alleged periodicity ; vol. xxx. p. 369. A
more recent paper by Prof. Olmsted, has been reprinted by Prof. Jameson,
in his New Edinburgh Phil. Journal for July last. Prof. Olmsted's first
paper contains an extensive collection of observations of the Meteors of Nov.
13, 1833, made in different parts of the United States, and gives various in-
ductions from them. In it also is proposed a theory to explain the phseno-
mena, which is thus finally expressed: — " That the Meteors of Nov. 13//i
consisted of portions of the extreme parts of a nebulous body, which revolves
around the sun in an orbit interior to that of the earth, but little inclined to
the plane of the ecliptic, having its aphelion near to the earth's path, and having
aperiodic time o/182 days nearly." — Silliman's Journal, vol. xxvi. p. 172.
Some observations on shooting stars, made at Devonport in November,
1836, have been noticed in our last volume, p. 234. Observations of the
same period, made at Berlin, Breslau, Frankfort-on-the-Maine, and Gum-
mersbach, will be found in Poggendorf's Annalen, vol. xxxix. p. 353 — 356.
The frequent appearance of shooting stars in August had been noticed
in England by Dr. T. Forster, (see Phil. Mag., First Series, vol.lxiv. p. 294),
and at Pavia, we believe, by M. Bellani. — E. W. B.]

Third Series. Vol. 1 1. No. 67. Sept. 1837. 2 N

[ 274 ]

XXXIII. Researches into the Cause of Voltaic Electricity. By
Mons. Auguste. De la Rive, Rector and Professor of
Natural Philosophy of the Academy of Geneva, Correspond-
ing Member of the Academy of Sciences of Paris.*
Abstract.
A T the commencement of 1828f, in a memoir entitled,
**■ Analysis of the circumstances which determine the direction
and intensity of the electric currents in a voltaic pair, I showed
by several experiments the impossibility of explaining the pro-
duction of voltaic electricity by the theory of contact, and the
necessity for having recourse to chemical action. At the end
of the same year I published an abstract of the researches
which form the subject of this article, in the Annates de Chimie
et de Physique^, which appeared in three parts in the memoirs
of the Societede Physique et d'Histoire Naturelle of Geneva, in
1829, 1832, and 1835. These three parts, especially the last,
were enriched with new facts not contained in the abstract which
I had given in 1828 ; but the principles were then stated, and
the new details that I added have only had the effect of proving
their exactitude. Thus in 1828, that is long before the labours
of Messrs. Ohm, Fechner, and Faraday, I had already given
the theory of the pile, founding it upon principles which have
been confirmed by the important researches of the physicists
whom I have just mentioned. But I ought to acknowledge
that these researches, particularly those of Mr. Faraday, have
led not only to the discovery of new laws of great value, but
in addition, have given, by the discovery of those laws, a more
solid basis to the chemical theory of the pile than was afforded
by my own labours. As my memoir forms a volume of 170
pages, and consequently cannot be inserted entire in a scientific
journal, I have endeavoured to give an abstract of it, as com-
plete as is possible, for the Philosophical Magazine, and I have
taken advantage of this circumstance to add to it a few facts
which I have not hitherto had an opportunity of publishing.

explanation of the principles upon which the che-
mical THEORY OF VOLTAIC ELECTRICITY IS, IN PART,
FOUNDED.

Principle I. — No electricity is developed by two bodies in
contact when they do not undergo any chemical action, provided
that there is likewise an absence of calorific and mechanical
action.

This principle, in support of which I produced a great num-

* Communicated by the Author.

f Annates de Chimie et de Physique, vol. xxxvii. p. 225.

t Ibid., vol. xxxix. p. 2&J.

Researches into the Cause of Voltaic Electricity, 275

ber of facts in 1828, has since that period been the subject of
a warm controversy. It has been attacked by many physicists
upon two grounds: 1. That electricity is produced by the
simple contact of bodies ; 2. That a good theory of the pile
cannot be given without admitting Volta's electromotive force.
A reply to the second objection is unsuited to a portion of the
memoir devoted to the chemical theory of the pile ; I shall here
therefore notice only the first, and endeavour to show the ex-
actitude of the principle which I have stated above.

The reason that it has been, and is still often supposed
that the simple contact of two heterogeneous bodies develops
electricity, is the difficulty of securing them from all calo-
rific and mechanical, and especially from all chemical ac-
tion. Are the bodies placed in a liquid ? When the liquid
does not attack them the air dissolved in the liquid oxidates
them if they are metals, or the water of the solution forms
hydrates with them if they are oxides. Are they left in
the air, or placed in some other gas? It is soon evident
from the alteration of their surfaces that they are attacked
by the air or the gas ; the finger or the humid substance
with which they are touched is also often the cause of che-
mical alteration at the points of contact. Indeed nothing
is more difficult than to secure the absence of chemical action
in these experiments. And when we consider on the one hand
how feeble is the electricity produced, since to perceive it the
assistance of the most delicate apparatus is required ; and on
the other what an immense quantity of electricity may be de-
veloped by the most feeble chemical action, as has been proved
by the experiments of Mr. Faraday ; we ought no longer to be
surprised that excessively feeble chemical action, the traces of
which cannot be detected but at the end of a certain time, may
give sensible signs of electricity.

But it is not impossible to exclude all chemical action, and
then no disengagement of electricity is perceptible even with the
most delicate apparatus. Thus pairs of platina and gold, or of
platina and rhodium, in extremely pure nitric acid, do not give
any current to the most sensible galvanometers; the same thing
occurs with platina and palladium in diluted sulphuric acid. In
order to the success of these experiments it is necessary to em-
ploy only highly purified substances, for one drop oi hydro-
chloric acid in the nitric, or of nitric acid in the sulphuric,
immediately renders the pairs active. From experiments
of this kind I shall produce one which appears to be pos-
sessed of some interest. Two plates of perfectly polished
steel were immersed in a flask filled with a solution of potash ;
one was insulated, and the other metallically fixed by itsextre^

2 N 2

276 M. De la Rive's Researches

mity to a plate of platina immersed in the same liquid ; the two
steel plates were inserted in the cork stopper belonging to the
flask in such a manner that the upper extremity of each passed
through the cork into the air. The portion of the two plates
immersed in the liquid remained perfectly intact ; at the end of
three years their surfaces had not lost any degree of polish ;
and in this respect there was no difference between them, not-
withstanding that one of them, in consequence of its contact
with platina, ought, according to the theory of Volta, to have
become oxidated, and that so much the more readily as the so-
lution of potash is a conductor of electricity ; but the part of
the plate which was inserted in the cork, and passed through
it into the air, was covered at the end of three years with a
very thick coat of oxide ; the insulated plate was also oxidated
at the same points, but in a much less degree, and it is worthy
of notice that the exterior of this plate presented a globule of
oxide of iron of the size of a pea, exactly similar in miniature
to those globules which are formed in iron tubes used for the
conveyance of water. From the preceding it follows that oxi-
dation must have commenced in order to the existence of an
electric current; the current produced by this oxidation de-
composes water, and in consequence determines a stronger oxi-
dation upon the steel plate in communication with the platina,
and this oxidation, in its turn, increases the energy of the cur-
rent; in this experiment, the water, which, produced by eva-
poration, moistened the cord, being mixed with a great deal
of air, performed at the same time the office of the exciting
body and the conductor.

I have indicated the causes which may determine a chemical
action when two heterogeneous bodies are placed in contact
without making use of a liquid, and I have ascertained that if
their occurrence be prevented no electric effect is obtained.
To avoid these sources of error Messrs. Pfaff and Becquerei
employed a condenser of which one of the plates was of copper
and the other of zinc, between which a metallic communication
was established by means of an insulated arc of copper. The
first of these physicists placed the two plates of his condenser
in a vacuum in hydrogen, or in azote carefully dried ; the se-
cond gilt the copper plate, and covered the plate of zinc with
a thin coating of lac-varnish ; but notwithstanding these pre-
cautions they obtained a development of electricity by the con-
tact of the two metals. Can it be said that there was no chemical
action in their experiments ? It may easily be proved that in
the medium in which M. Pfaff placed his plates sufficient at-
mospheric air always enters to produce a slight oxidation of the
surface of the zinc ; and that in M. Becquerers experiments the

into the Cause of Voltaic Electricity. 277

coating of varnish was too thin to prevent this oxidation, which
took place through the pores that the alcohol produced by eva-
porating. In short, if a plate of zinc well brightened \decap4\
be employed, it will be seen that whether M. Pfaff's method,
or that of M. Becquerel be pursued, it will become tarnished at
the end of a certain time ; proving that there has been an oxi-
dating action of the air, and the formation of a suboxide. The
only means by which I have succeeded in preventing all elec-
trical signs from the contact of the two plates is, by covering
the plate of zinc with a layer of lac-varnish, so thick as not to
be transparent ; in which case the air no longer gains access to
the zinc, and consequently cannot oxidate it.

Sufficient attention has not in general been paid to the for-
mation of these coatings of suboxide upon the surface of most
of the metals, the existence of which may be easily proved by
comparing the parts of a metallic surface recently brightened
[decape] with one which has been for some time exposed to
the air. This formation is often very rapid, which is the rea-
son that much more distinct electric signs are obtained by
touching an electroscope with metallic surfaces at the very
moment after they have been brightened \decap£\\ this is
more especially true when, insulating these surfaces by employ-
ing a glass handle instead of the fingers, the oxidating action
of the air is the only chemical action to which they are ex-
posed. I have also proved the rapidity with which these coat-
ings of suboxide are formed, in studying the nature of the
electricity which is developed by the well-brightened [decape]
surfaces of most of the metals when they are rubbed with
wood, cork, or a dry finger, or any conducting body what-
ever, not metallic. If these surfaces be rubbed the very mo-
ment after they are brightened [decaptf] the electricity ac-
quired by the metal is always negative; but if the rubbing
be deferred for a longer or shorter time, according to the na-
ture of the metal, the electricity, even in dry air, is positive,
excepting with the metals which are not oxidable, or which
are only so in a very small degree. The cause of this altera-
tion is, that in the second case a coating of suboxide has had
time to form ; it is removed by the substance with which it is
rubbed, to which it adheres, and the friction then occurs be-
tween the metal and its oxide ; on which account the first is
positive. Lastly, I shall cite the following from the facts
which I have collected to prove this rapid oxidation of the
surface of most metals : If a metallic plate (not of platina),
which after having been brightened [decapf] has remained
for some time exposed to the air, be fixed to the negative pole
of a pile, and a plate of platina to the positive pole, and the

278 M. De la Rive's Researches

two plates be immersed in a solution of sulphuric acid, the
oxygen always appears upon the positive plate a few seconds
before the hydrogen is seen upon the negative ; a fact which
can only be explained by admitting that the first quantities of
hydrogen disengaged have been employed in deoxidating the
negative metal : it is not necessary that this metal be very
oxidable ; either silver or copper will answer ; all that is ne-
cessary is that the pile be feeble, and the solution a good con-
ductor.

The experiment which is considered as the most favourable
to the theory of contact is that of putting in contact platina
and peroxide of manganese, when the former of those sub-
stances is found to be positive and the latter negative. Other
peroxides, such as that of lead, will give the same results. By
putting a thin plate of wood, instead of one of platina, upon
the plate of the condenser, and by placing on the wood the
peroxide which is held between the ringers, the condenser of
positive electricity is charged. If a piece of paper steeped in
pure water, or what is still better, in acidulated water, be sub-
stituted for the wooden plate, and the peroxide be touched
with a piece of wood or with a dry finger, the condenser of
negative electricity is charged. Thus the development of
electricity is not due to the contact, but to the slight deoxi-
dation that the peroxides, such as those of manganese and
lead, undergo by contact with humid bodies, or to the foun-
dation of hydrates due to the same circumstance. In the
same manner may be explained the slight instantaneous
current which M. Becquerel obtained by immersing peroxide
of manganese and platina in pure water. This current only
occurs when the circuit has been interrupted for fifteen or
thirty minutes, in order to allow of the accumulation of elec-
tricity due to the slight chemical action; which accumulation,
as we shall presently see, happens in this instance alone, in
consequence of the imperfect conductibility of the elements
of the pair. The same phenomenon occurs with gold and
platina, and arises from the slight oxidation of the gold ef-
fected by the operation of the air dissolved in the water. It
is true it is very feeble, but if allowed to accumulate for about
half an hour it will be capable of producing an instantaneous
current perceptible with a very sensible galvanometer.

Principle II. — All chemical action disengages electricity ;
but the electricity disengaged is not, in eveiy case, nor under
every form yrro-portional to the vivacity of the chemical action.
Two principal circumstances may explain this anomaly ; viz.
the immediate recomposition in a larger or smaller proportion
of the two electricities at the points at which they are separated

into the Cause of Voltaic Electricity. 279

by chemical action ; and the particular nature of this action,
which, according to the bodies between which it is exerted,
gives rise to electric effects more or less intense.

When there is chemical action between two bodies, one
takes possession of the positive electricity, (these are in gene-
ral oxygen, oxides, &c.) the other of the negative electricity,
(these are in general the bases, metals, oxides, &c). Each of
these bodies is in a state of electric tension, and it may be ren-
dered sensible by putting one of them in communication with
an electroscope, and the other with the earth. There is an
electric current when the two bodies are united exteriorly at
the points at which the chemical action takes place, and it may
be rendered sensible by employing the metallic wire of a
galvanometer to effect this union. Thus when a communi-
cation is established between the condenser of an electroscope
and an oxidable metal, and it is touched with the finger or
any other humid conductor, the metal takes the positive elec-
tricity, which it transmits to the condenser, and the humid con-
ductor the negative, which passes into the earth. In the
particular case in which the condenser is formed of one plate
of zinc and one of copper, the negative electricity which the
zinc acquires by the chemical action exerted upon its surface
by the air or some other gas, passes in part into the copper
with which the zinc communicates metallically ; the positive
electricity with which the layer of air adhering to the sur-
face of the zinc is charged passes into that metal, or, after
having neutralized what remains of the negative, charges it
positively; by means of condensation a sufficient quantity of
positive electricity is accumulated upon the surface of the zinc
and of negative upon the copper to admit of their presence
being easily perceived by the electroscope ; it may also be
seen, as experiment has constantly proved, why the electric
tension of each of the plates is the moiety of what it would be
if one of them were put in communication with the earth and
the other with the electroscope. In the same manner when two
metals communicating with each other metallically are im-
mersed in a liquid which exerts a chemical action upon one of
them, and not upon the other, the positive electricity with
which the liquid becomes charged, and the negative which is
taken by the attacked metal, unite by the intervention of the
metal not attacked, and the conductor which unites the two
metals, constituting the electric current which it is said leaves
the metal attacked in a state which is called positive in rela-
tion to the other. It is not necessary that the second metal
should not be attacked ; it is sufficient that it be attacked in a
less degree than the other in order to the establishment of the

280 M. De la Rive's Researches

current, in consequence of the difference in the quantities of
electricity developed by the two unequal chemical actions.

But, it will be said, if such be the fact, how is it that a
stronger tension is not obtained by putting an oxidable metal
in communication with the electroscope and then immersing
it by its extremity in an acid solution instead of holding it in
the fingers ? How is it that the strongest electric currents are
not always produced by the most lively chemical actions, and
that a metal immersed in a liquid which attacks it but feebly,
forming a pair with another metal, or a piece of the same me-
tal immersed in a liquid which acts upon it strongly, can be
sometimes positive, that is to say, that whence the current
commences ? To explain these anomalies and reconcile them
with the chemical theory, recourse must be had to a principle
which indeed flows from the nature of things, viz. the imme-
diate recomposition in a larger or smaller proportion of the two
electricities developed by chemical action. It is necessary then
carefully to distinguish the electricity perceived from the elec-
tricity produced ; the latter must evidently be proportional
to the extent of the chemical action, that is, that in a given
time it depends upon the number of chemical atoms which
are combined, and consequently upon all the other circum-
stances which may have exerted an influence upon the num-
ber of these combinations (the extent of the surface exposed
to chemical action, the vivacity of that action, &c). The elec-
tricity perceived is a proportion of the electricity produced, a
proportion which depends upon the relative conductibility of
the bodies entering into the system in which the electricity is
propagated, upon the disposition of the different parts of the
system and upon the nature of the apparatus to be employed
in showing the presence of the electricity, &c. ; circumstances
which, as we shall see, all have an influence upon the degree
of facility with which the two electric principles follow some
certain course, or become again immediately united to the
same surface from which by chemical action they are separated.

When a capsule of platina filled with sulphuric or diluted
nitric acid is placed upon the plate of a condenser, and a plate
of zinc, held in the fingers, is immersed in it, a very feeble
charge is given to the plate of the condenser, although the che-
mical action may have been very lively ; the reason is, not that
there has not been an enormous disengagement of electricity,
a fact which may be proved by employing this electricity in
producing a current; but in this experiment the negative elec-
tricity developed in the zinc unites with the positive with much
greater facility than it can pass through the fingers and the
body of the experimenter in order to lose itself in the earth ;

into the Cause of Voltaic Electricity. 281

there will therefore only be a very feeble positive tension, often
scarcely any. But if the diluted acid be replaced by concen-
trated sulphuric acid, though the chemical action will be less
lively, the electric tension will be much stronger, this acid being
a very bad conductor; and the passage of the electricity from the
liquid to the metal immersed in it being extremely difficult, the
two electricities uniting immediately upon the surface attacked
in a much smaller proportion : if, instead of a piece of metal, a
piece of wood rather moist be immersed in the concentrated sul-
phuric acid, the positive tension acquired by the acid is still
stronger. If a capsule made of an oxidable metal be employed,
and, after heating it, a few drops of a liquid capable of attack-
ing it at that high temperature in ever so small a degree (pure
water is sufficient), be poured into it, a quantity of negative
electricity is developed, which is sufficiently strong to be sen-
sible without the assistance of the condenser, and even to give
sparks. In this case the drop of liquid injected into the heated
capsule is converted into vapour while it is attacking the metal,
and carries off with it the positive electricity, which cannot then
combine immediately with the negative electricity left in the
metal ; but if even the smallest quantity of the liquid remains
in the capsule unvaporized the immediate recomposition takes
place, and only very feeble traces of negative electricity can be
obtained. If the electricity developed by the action of a gas,
or by that exerted by a humid body, such as the hand or a piece
of wood, upon the metal with which it is in contact, is often
much stronger than the electricity resulting from the much live-
lier action of a liquid, the reason is, that in the former case the
immediate recomposition of the two electrical principles is al-
most null, in consequence of the imperfect conductibility of the
exciting bodies, and that the electricity produced is almost en-
tirely perceived. There is, however, a slight recomposition,
for the negative tension of an insulated metal is sensibly aug-
mented by giving a translatory motion to the gas which attacks
its surface; the consequence of which is, that the positive
electricity accumulated in the gas being removed with it, can-
not unite with the negative left in the metal*.

The principle of immediate recomposition of the two elec-

• The most successful method of performing experiments of this kind is,
to take tubes of zinc, copper, or any other metal susceptible of attack, to
suspend them to an insulating handle, and cause a current of very dry air
mixed with a little chlorine to pass interiorly. If a communication be esta-
blished between the metallic tube and an electroscope, it will be found
charged with strong positive electricity. The positive electricity carried
off by the current of gas may also be collected by causing the current to
pass through a tube of platina after it has passed through the metallic tube
which it has attacked.

Third Series. Vol. 11. No. 07. Sept. 1837. 2 O

282 M. De la Rive's Researches

tricities, applies also to the production of electric currents in a
pair. In very lively chemical actions the larger proportion of
the two electricities developed often undergoes this recompo-
sition ; a small part only runs through the whole circuit, espe-
cially if it be not a very good conductor ; which is the reason
that the strongest currents are not always those produced by
the most lively chemical actions, and that in a pair the metal
the most attacked is not always the positive one, that is, the one
whence the current commences. However, the latter case oc-
curs only when each of the two metals of the pair are immersed
in different liquids; a single example shall be given. A plate
of zinc is placed in concentrated sulphuric acid, and a plate of
copper is immersed in nitric acid ; the two acids are imme-
diately in contact, and the two metallic plates communicate
by means of the wire of a galvanometer. In this pair the
zinc is positive though it be much less attacked than the cop*
per; because the two electricities developed by the action of
the sulphuric acid upon the zinc can be more easily reunited
by making the tour of the circuit, than by passing from the
sulphuric acid to the zinc, and reciprocally ; while, on the
contrary, the two electricities developed by the action of the
nitric acid upon the copper reunite immediately with the
greatest facility, in consequence of the conductibility of the
nitric acid, and the ready passage of the electric current from
that acid to the copper ; while to make the circuit they would
be obliged to traverse the concentrated sulphuric acid,
which is a very imperfect conductor, and pass from the
zinc to the acid, — a very difficult passage. Two circumstances
prove the exactitude of this explanation : 1. The same result
is obtained in the preceding experiment by substituting a plate
of zinc, similar to that which is immersed in the sulphuric acid,
for the plate of copper immersed in the nitric acid. 2. If a
capsule of platina be put upon the plate of the condenser, and
filled in succession with nitric acid, and concentrated sul-
phuric acid, and a plate of copper or of zinc, held between
the fingers, be immersed in the first-mentioned liquid, and a
plate of zinc in the second, a much stronger positive electri-
city is obtained in the second case than in the first.

The foreign substances which are often mixed with metals
greatly facilitate this immediate recomposition, by giving rise
to local actions. Thus, as I have already shown,* the lively
action of diluted sulphuric acid upon common zinc is due
to a small proportion of iron contained in the zinc, and to the
electrical currents which, taking place upon its surface, pass

• Bibl. Univer., April 1830. [See also Phil. Mag. and Annals, N. S.
vol. viii, p. 298. Edit.]

into the Cause of Voltaic Electricity. 283

from the particles of zinc to the particles of iron. These cur-
rents decompose water; the hydrogen is disengaged, and the
oxygen, by combining with the zinc, increases the energy of
the current, which thus successively becomes cause and effect;
and the action may be observed to go on constantly increasing
in intensity, as if it were the effect of an accelerating force,
and neither to be constant or diminished but when the surface
of the metal becomes covered with a little suboxide black ari-
sing from the decomposition of the sulphate of zinc by the local
currents. If, instead ofcommonzinc, distilled, and consequently
very pure zinc be employed, a very feeble chemical action is
obtained by immersing it in diluted sulphuric acid; but if a
pair be formed by uniting it metallically with platina immersed
in the same liquid, the intensity of the chemical action which
takes place upon its surface is augmented; the disengagement
of the hydrogen and the oxidation of the zinc become more
and more energetic in consequence of the current which is
established from the zinc to the platina, and which here also
is successively effect and cause. The limit to the augment-
ation of intensity is only the effect of the constantly increasing
resistance experienced by the current in the circuit, in pro-
portion to its increasing strength ; the resistance arises from
the imperfect conductibility of the parts of which the circuit
is composed, and the deposit of suboxide of zinc which takes
place, not upon the metal itself, as in the preceding case, but
upon the platina. The only difference which exists between
the effects resulting from the employment of distilled zinc
when united to platina, and of the zinc of commerce is, that
in the first case the currents traversing a longer circuit may
be perceived, while in the second, being almost molecular, they
cannot be apprehended ; but they exist equally in both cases.
It will now be easily understood why, in the same circum-
stances, a plate of common zinc with another metal forms a
much less powerful pair than a plate of distilled zinc, though
it produces a much livelier chemical action ; it may also be
understood why the latter zinc is negative when it forms a
pair with distilled zinc which is less attacked than itself. Very
great advantage will therefore be found to result from the em-
ployment of distilled zinc in the construction of voltaic piles
instead of common zinc ; for with the former nearly all the
chemical action can be utilized, since it is in its totality cause
and effect ; whilst with common zinc the greater part of it is lost
by immediate recom position ; the proportion utilized is there-
fore but a small fraction of the total quantity of zinc dis-
solved.

Since I made known the properties of distilled zinc, Mr.

2 O 2

284 M. De la Rive's Researches

Faraday has remarked that they are also possessed by amal-
gamated zinc : it appears from the observations of Professor
Daniel that the amalgamated zinc is considerably attacked the
moment it is immersed in acidulated water, but that the hy-
drogen which results from this action prevents the continu-
ation of it, by remaining strongly attached to the mercury of
the amalgam ; but that if a communication be established be-
tween the amalgamated zinc and a plate of platina or copper
immersed in the same liquid, the current which results from
the action upon the zinc removes the hydrogen to the platina
instead of leaving it upon the mercury, and the surface of the
zinc being no longer defended can be oxidated in the same
manner as if it were not amalgamated.

The principle of the immediate recomposition of the two
electricities which has just been explained so far as it is con-
nected with the production of electricity by chemical action,
applies to every other mode of developing that agent, such as
heat, friction, or pressure. In every case the total quantity,
not of electricity produced, but the quantity perceived, or what
maybe called the tension of the source, essentially depends upon
the greater or less degree of facility with which the two elec-
tricities can be immediately recomposed at the same points at
which they are separated ; this facility varying according to
the nature of the substances employed.

Thus, according to what precedes, the quantity of electri-
city produced in a chemical action will depend solely upon
the number of the atomic combinations which take place
during the continuance of that action, as has been so well
shown by Mr. Faraday ; but the intensity of the current will
depend upon the proportion of the two electricities produced
which passes, in order to its neutralization, through the con-
ductor where this intensity is measured ; so also the energy of
the tension will depend upon the degree of difficulty expe-
rienced by the two electricities, separated by chemical action,
in reuniting immediately. However, it is not probable that
this is the only circumstance having an influence upon the in-
tensity of the current and the tension. Some experiments
incline me to think that the very nature of chemical action
exerts an influence in this respect : we will suppose, for ex-
ample, that all the electricity produced by the oxidation of a
certain number of atoms of zinc, and all that resulting from the
oxidation of the same number of atoms of copper, pass, in the
same time, through the same conductor ; the first would pro-
duce much more intense dynamic effects than the second. It
would appear, indeed, according to some researches which I
published in the Annates de Chimie et de Physique, in January

into the Cause of Voltaic Electricity, 285

1836, that the currents produced by the combinations of the
same number of atoms effected in the same period of time,
would be so much the more intense in proportion to the in-
crease of strength of the chemical affinity which unites the
atoms of each combination.

I shall not here enlarge upon this point, which, considering
its importance, deserves to be separately discussed, and to
which I hope to return immediately, adding further develop-
ments upon the subject to the brief statement which I published
in the Annates de Chimie. The theory of the pile is, however,
independent of this question; all its importance in relation to
that theory being that it proves : 1 . That there is no develop-
ment of electricity by the simple contact of two heterogeneous
bodies. 2. That chemical action produces electricity ac-
cording to the laws that have been indicated. 3. That the
quantity of electricity developed in a given time depends upon
the number of combinations which take place in that time.
4. That the tension of an electric source and the intensity of
a current depend upon the proportion of the electricity pro-
duced, which, under a statical or a dynamical form, reaches the
instrument by which the tension or the intensity is measured.

Part 11.— Theory of the Voltaic Pile.
If all the bodies through which the electric current is passed
were sufficiently good conductors to admit of the two elec-
tricities, which have been separated by the chemical action
exerted upon one of the metals of a pair, following, in totality,
in order to reunite, the direction presented to them by those
bodies, instead of being neutralized in a larger or smaller pro-
portion upon the surface where they have been developed,
voltaic piles would be unnecessary ; a single pair would pro-
duce every effect, with an intensity corresponding to the ex-
tent of the surface. But this is far from being the fact ; ex-
cepting a few electro-magnetic phaenomena, the greater part
of the effects of voltaic electricity can only be produced by
making the electric current pass through conductors more or
less imperfect ; wherefore, if a single pair be employed the
result is, that, as with common zinc, there is a local action
which gives no perceptible current; or, as with distilled zinc,
there is scarcely any effect or none at all, because no current
can be established through the circuit. The use of the pile
is therefore to facilitate the passage of the current through
imperfect conductors, and not to increase the quantity of elec-
tricity; for the utmost that can be effected by a pile composed
of a certain number of similar pairs is to compel all the elec-
tricity produced by only one of its pairs to pass through the

286 M. De la Rive's Researches

conducting body which connects its poles. The only means
of attaining this object is to separate the two metals of a pair
by other pairs as similar to the first as possible ; these inter-
mediate pairs, the number of which should correspond to the
more or less imperfect conductibility of the bodies interposed,
will each produce as much electricity as the extreme pair, but
these electricities do not pass through the conductor ; they
only compel the electricities of the extreme pair to pass through
it almost in totality. We shall now endeavour to show how
this effect is produced. We shall take a pile in activity ; and
suppose that all the pairs of which it is composed are so ex-
actly similar to each other, in every respect, that the free elec-
tricity upon each of them has the same intensity. Let b be a
pair in the pile, taken at hazard, and disposed in such a man-
ner that its zinc is immersed in the same liquid as the copper
of the pair a which precedes it, and its copper in the same li-
quid as the zinc of the pair c which follows it. The chemical
action of the liquid upon the zinc of the pair b develops in it
a certain quantity of electricity ; the portion of this electricity
which does not undergo immediate recomposition remains free,
and the same for all the pairs, they being similar and symmetric-
ally disposed with relation to each other. According to this
the positive electricity of b, developed by chemical action, in the
liquid in which the copper of a is immersed, neutralizes the
negative electricity of this latter pair, which is equal to it. In
the same manner the negative electricity of b, which by che-
mical action is carried to the zinc, and thence to the copper
in contact with the zinc, neutralizes the positive electricity of
c, which also is perfectly equal to it. There remains then an
excess of free positive electricity in the liquid in which the
zinc of a is immersed, and an excess of free negative electri-
city perfectly equal upon the copper of c. But these free ex-
cesses are neutralized by the equal and opposite electricities
of the following pairs, with regard to which we may reason in
the same manner as for the pairs a, b9 and c. Thence there
results an excess of free positive electricity at the extremity of
the pile at the side of a, and an exactly equal excess of nega-
tive electricity at the extremity situated at the side of 6. Such
is found to be the fact if a communication be established be-
tween each of the extremities and an electroscope; and if they
be united by a conductor, the two excesses of free electricity
are collected together and form the current. The intensity
of this current, as experiment has proved, ought to be per-
fectly equal to that of the current which is established in the
pile itself, between all the pairs.

It most frequently happens that the quantity of freeelectri-

into the Cause of Voltaic Electricity. e2S7

city disengaged upon each pair of a pile is not mathematically
the same. The difference may arise from one of these three
causes: either that the pairs have not exactly equal sur-
faces, that the metals of which they are formed are not per-
fectly similar, or that the liquids in which they are immersed
are not completely identical ; circumstances which all have an
influence upon the total quantity of electricity produced in a
given time, and upon the portion of that electricity which re-
mains free. However, experience teaches, that when the two
poles of a pile are united by a conductor, the current which
traverses this conductor is still mathematically equal to that
which traverses each of the pairs of the pile. To establish
this important result, instead of soldering the zinc and copper
of the same pair to each other, an independent conductor must
be fixed to each. By means of these two conductors a me-
tallic communication is established between the two metals of
the pair, by the intervention of one of the wires of a double
galvanometer, the second wire of which serves as conductor
to the current of a second pair of the same pile, or to effect a
communication between the two poles. If these two currents
be carefully made to pass in contrary directions in each of the
wires of the galvanometer, their action upon the needle will
always be found absolutely null, provided they are mathema-
tically equal. This equality is easily explained. Take the
most feeble pair in the pile; let b be this pair; the positive
electricity disengaged by b cannot neutralize all the negative
of a ; there will remain then in the copper of a an excess of
negative electricity which will retain, by neutralizing it, an
equal quantity of positive ; the result will be that a, though
much stronger than b9 can only set at liberty a quantity of
positive electricity equal to that of b. So also the negative
electricity of b can neutralize only a part of the positive of c;
the rest of this positive electricity will neutralize an equal part
of the negative of the same pair; and consequently c also can
only liberate a quantity of negative electricity equal to that of
b. It appears from this analysis, that the current of each pair,
and consequently the current of the whole pile, should be equal
to the current produced by the weakest pair. Now, experi-
ment fully proves, that if a feeble pair be introduced into a
pile composed of energetic pairs, the immediate result is a
considerable diminution in the force of the current of the pile,
and consequently of the current of each of the other pairs ;
but this reduction is never sufficient to render this current
equal to that which would be developed by the pair intro-
duced in an isolated state. Indeed, any pair whatever ne-
cessarily produces a greater quantity of electricity when it is

288 M. De la Rive's Researches

m

in the circuit than when it is isolated ; in the latter case the
two electricities have a tendency to reunite immediately in a
larger proportion than when the pair is placed between two
others, one of which takes possession of its positive electricity
and the other of its negative : in addition, the current which
is established in the liquid in which the oxidable element of
the pair is immersed, facilitates the oxidation of that element
by decomposing the liquid, and consequently augments the
quantity of electricity developed. This is particularly the
case when piles are employed consisting of pairs of copper
and distilled or amalgamated zinc; the current itself is at
once cause and effect. Sometimes the pair introduced is so
feeble that it can only be considered as an imperfect conduct-
or interposed in the liquid which unites the opposite elements
of the two pairs between which it is placed ; its influence then
consists solely in diminishing the quantity of the opposite
electricities of these pairs which would neutralize each other,
and consequently the current of all the other pairs and that
of the whole pile. If the diminution of effect be due to the
cause which has just been stated, it ought to be the same
whatever be the direction in which the elements of the pair
introduced are disposed ; and I have had opportunity of ve-
rifying that such is the fact.

We shall now inquire whether the theory which has just
been enunciated will explain all the phaenomena presented by
voltaic piles ; and to this end we shall investigate in succession
their tensile and their dynamic effects.

Tensile effects. — When a pile is insulated and its two poles
are not united by a conductor, an equal quantity of positive and
negative electricity should, in agreement with what we have just
seen, be found at each of them. These two electricities, con-
stantly carried towards a pole, would in the end acquire an
enormous tension if the pile itself which separates them werenot
a more or less perfect conductor, which allows them in part to
reunite in neutralizing each other; it acts in this respect as the
band of moist paper placed by Volta between the two poles of
the pile, or as a secondary pile placed in the same position.
Commencing at each of the poles, an electricity should there-
fore be found in the pile of the same nature as that of the pole,
but constantly diminishing towards the middle where it is null,
because that is the point of meeting and consequently the
place of neutralization of the two electricities ; and this is
precisely what experiment demonstrates. The recomposition
of the electricities of the two poles, which takes place through
the pile itself, is proved by the following fact, that when one
of the poles is put in communication with the earth, the other

into the Cause of Voltaic Electricity. 289

requires a much stronger tension ; but the difference between
the tension in the two cases increases in proportion as the
liquid with which the pile is charged is a better conductor ;
such should be the fact, for when the liquid is a good con-
ductor the two electricities can reunite with greater facility
through the pile, if one of them be not furnished with means
of flowing into the earth. Numerous experiments have been
made in relation to this circumstance by charging the same
pile in succession with river water (Rhone water), a solution
of sulphate of soda, and a diluted solution of nitric acid. I
have observed, in particular, that to obtain the maximum ten-
sion the pole where the tension is perceived must be left in
contact with the condenser for a considerable time, if the li-
quid with which the pile is charged be simply water ; rather
a shorter, though still an appreciable time, if it be sulphate
of soda ; and, lastly, an almost insensible period if it be the
solution of nitric acid. The following are the results of an
experiment performed with a pile of ten elements, zinc and
copper, the surfaces four inches square, charged with river
water :

Duration of contact of the pole with the condenser,

15"

30"

60".
Divergence of the gold leaves of the electroscope,

2°

6°

(The gold leaves touch the envelope of the electroscope).

If we wish to charge the condenser twice in succession with
the same pile, a period of time must be allowed to elapse be-
tween the two charges, varying according to the nature of the
liquid with which the pile is charged, exactly in the same
manner as the duration of the contact of the condenser and the
pole varies. These results may easily be explained by consi-
dering, that as river water has much less action upon zinc, a
much longer time is required for the development of a certain
quantity of electricity, while with saline and especially with
acid solutions, this electricity is developed instantaneously.
That in the first case, notwithstanding its slow production,
there may still be a considerable quantity of electricity accumu-
lated at the poles, is a fact which arises from the imperfect
conductibility of the pile. I have seen a pile of 120 elements,
zinc and copper, charged only with pure water, give sparks at
both its poles, in very dry weather in winter, like an electrical
machine, while the same pile, charged with an acid solution,

Third Series. Vol. 1 1. No. 67. Sept 1837. 2 P

290 M. De la Rive's Researches

gave scarcely any signs of tension to an electroscope. It is the
same with dry piles, in which the humidity with which the
paper is always more or less impregnated performs the office
of conductor, and they present in a much more obvious man-
ner all the phenomena produced by piles of zinc and copper,
charged with pure water. I must not omit to say that, in
operating with the last-mentioned piles, care must be taken
completely to insulate all the parts of which they are composed,
by uniting their pairs by glass rods covered with lac-varnish
instead of wooden rods, and by employing as troughs glasses
insulated by means of supports of resin.

Dynamic effects of the pile. — For investigating the dyna-
mic effects of the pile, I have employed either a galvanic
multiplier, Breguet's metallic helix, which I placed in the
circuit to appreciate the heat developed by the current, or a
very sensible apparatus intended to measure the gases result-
ing from the decomposition of the water by the current in
passing through an acid solution. In my memoir I have given
a detailed description of this apparatus, and of the manner in
wThich I employed it.

In the first place, it is evident that whatever be the dyna-
mic effect to be produced, when the number of pairs is con-
stant, the quantity of electricity disengaged in a given time,
and consequently the intensity of the effect produced, increase
in proportion to the increased extent of the surface of each
pair. This increase, however, is far from being the same for
the different classes of effects, as shall be shown elsewhere.
But the true question which is here to engage our attention is
this : A surface attacked by a certain solution, and a corre-
sponding surface of a metal less attacked, or not at all, being
given, what is the number of pairs to be formed of them to
produce the most considerable dynamic effect? At the first
glance the reply does not appear doubtful. A single pair must
be made of them, for, according to our theory, the quantity
of electricity which circulates through the conductor is always
equal to that developed in a single pair; the electricities of the
interior pairs reciprocally neutralizing each other. But this
theoretical reply is only true so far as the conductor which
unites the two poles can be considered as perfect ; thus it is
true with relation to all the dynamic effects that can be pro-
duced by employing, as a conductor, a copper wire of suffi-
cient thickness not to be heated by the current. It is true
also in a less degree, that is, two or three pairs must be formed
of the given surfaces to produce the maximum of effect, when
the connecting wire is, either from its nature or its dimen-
sions, a worse conductor, in which case the Wire becomes

into the Cause of Voltaic Electricity. 291

heated even to redness in consequence of its resistance to the
passage of the current. But the reply is completely false when
the conductor is imperfect, such as a liquid or two points of
charcoal ; a rather considerable number of pairs must be made
of the surfaces in this case in order that the current may pass,
decompose, and heat the liquid, and produce heat and light
between the two points of charcoal. It is therefore exceed-
ingly inaccurate to distinguish the nature of effects by the
number of pairs most favourable for their production ; and
to say, for example, that to produce considerable calorific
effects, piles of large surfaces and a small number of pairs
must be employed, — and inversely, for considerable chemical
and physiological effects. Experiment has proved that the
degree of conductibility of the body interposed between the
poles, alone determines the number of pairs most favourable,
whatever be the nature of the effect produced, and that this
number is exactly in an inverse ratio to the conductibility of
the body.

This law flows immediately from the theory of the pile
which we have enunciated. In fact, when the two electrici-
ties are accumulated at the two poles of the pile, they have,
as we have seen, two different ways of neutralizing each other,
that of the pile itself and that of the conductor, which unites
the two poles. The larger or smaller proportion of the two
electricities which follow either of these paths, depends upon
the relative facility afforded by them for their reunion ; if the
pile be in ever so small a degree a better conductor than the
body interposed between its poles, no portion of the current,
or only a very feeble one, will traverse this body. In every
case, therefore, the number of pairs formed from the given
metallic surfaces must be large enough to render the pile a
worse conductor than the body placed between its poles.
Care must also be taken to make all these pairs equal, for
should one of them be smaller than the others, its influence,
as we have already seen, immediately diminishes the quan-
tity of free electricity which circulates in a given time through
the conductor. This result is in exact agreement with my
own observations, and with some experiments very recently
performed by Mr. Binks, (Phil. Mag., July 1837,) which
confirm with the most remarkable precision the theory which
we have given.

Examination of circumstances "which affect the power of the pile.

We have supposed in the preceding paragraph that the
quantity of metal employed to make a pile is constant ; but
it may happen that in a given pile either the surface or the

2 P2

292 M. De la Rive's Researches

number of its pairs may be increased. What will be the re-
sult of these species of augmentation in theory and in practice?
We proceed to inquire.

Experiment teaches us that if the number of the pairs re-
main constant, the tension of the pile is not increased in a
sensible manner by increasing their surfaces, and that the
dynamic effects are increased in proportion as those effects
are produced by better conductors placed between the poles
of the pile. I shall not relate, from fear of prolixity, the nu-
merous experiments which have conducted me to this law ;
besides, many physicists had already made analogous obser-
vations. The theoretical reason for this result may be easily
imagined. It is true, that by increasing the surface of the
pairs, the quantity of electricity disengaged in a given time is
increased, but the interior conductibility of the pile is also
increased, as may be readily understood. Now, for effects of
tension, these two circumstances nearly counterbalance each
other; I am, however, disposed to believe, from experiment,
that when the pile is charged with a liquid which is a very
good conductor, and which exerts a lively chemical action
upon one of the metals of the pairs, an increase of the surface
of the pairs diminishes the tension. As to the dynamic effects,
it may be clearly seen that when they are produced in much
better conductors than the pile, as much is gained by increa-
sing the surface of the pile, and in consequence the quantity of
electricity which circulates in a given time through these con-
ductors. But if the bodies placed between the poles be im-
perfect conductors, and only in a small degree better con-
ductors than the pile, by increasing the surface of the pairs,
the quantity of electricity which circulates through those bodies
is increased ; but the conductibility of the pile is also aug-
mented, and as that of the bodies interposed between the poles
does not alter, a larger proportion of the total amount of the
electricities necessarily reunites through the pile itself. This is
the reason that in the latter case the dynamic effects do not in-
crease with the surface of the pairs in so large ajproportion as
in the former case; this is also the reason that in certain dy-
namic effects, such particularly as physiological effects, the
augmentation is insensible.

We will now inquire what will be the result, if, without al-
tering their surface, the number of pairs be increased, taking
care that the additional pairs are exactly similar to those of
which the pile is already composed. The following are the
results :

I. That the tension of the pile increases constantly with the
number of the pairs, but that for dynamic (magnetic, calorific,

into the Cause of Voltaic Electricity,

293

and chemical,) effects, there is a limit in the number of pairs
which produces them with the greatest degree of intensity.

II. That the number of pairs which in each case produces
the maximum of effect, diminishes in proportion as the body
placed between the poles is a better conductor, and the liquid
interposed between the poles a worse one, and less adapted to
exert a lively chemical action.

III. That it often happens, especially when the pile is not
very energetic, that when the number of pairs the most fa-
vourable to the production of a certain effect, in each case,
has been exceeded, the diminution in the intensity of the effect
which results from the addition of other pairs, ceases when
this addition amounts to a certain number; that the effect then
again becomes as intense as it was previously, to diminish a
second time in the same manner by again increasing the num-
ber of pairs.

IV. That whatever be the absolute intensity of the effects
produced by a pile, this intensity diminishes with a rapidity
proportional to the amount of the number of the pairs com-
posing the pile, such at least is the fact when the conductor
placed between its poles is very good, and the liquid with
which it is charged exerts a feeble chemical action.

As the preceding results are entirely new I shall describe
some of the experiments by which they were arrived at.

Exp. I. — Pairs of zinc and copper, with surfaces four inches
square charged with slightly acidulated water.

Number of Degrees of

Pairs. Breguet's helix.

20 65°

15
10
5
3
2
1

50
40
40
43
35
25

Exp. II. — Pairs of zinc and copper, with surfaces sixteen
inches square charged with acidulated water which has been
several times employed, and which consequently is more saline
than acid.

10

• • <

17°

20

• •

17

40

. .

10

60

• .

25

20

. .

20

294

M. De la Rive's Researches

Exp. III. — Pairs the same as the preceding bid charged with
a solution still less acid.

10

12°

20

14

30

15

40

6

50

7

60

9

80

10

90

11

100

9

120

7

Exp. IV. — Pairs the same as the preceding.

Number of Number of seconds necessary-

Pairs, to obtain the same volume of gas

60 75"

120 52

180 43

tp. V. — Another experiment with the same pairs.

10 66"

20

25

30

22

40

17

60

14

80

13

100

12

120

15

By employing pairs similar to the preceding, with the double
magnetic galvanometer, I found that two, twenty, and a hun-
dred and twenty pairs developed perfectly equal currents.
The strongest currents were developed by fourteen and seventy
pairs.

To exhibit the influence of the duration of the effect upon
its intensity, I shall produce some further experiments per-
formed with pairs with surfaces only four inches square, but
charged with a strong solution of nitric acid. Two pairs gave
in the first instant 215° of Breguet's helix, at the end of five
minutes 100°, at the end of ten minutes 80°. In another
experiment four pairs gave in the first instant 300°, at the
end of five minutes 160°, at the end of fifteen minutes 100°.
Lastly, six pairs gave at the first instant 500°, but the effect
diminished with great rapidity. The preceding pairs had
never been employed; but after using them a certain number

into the Cause of Voltaic Electricity* 295

of times at considerable intervals, I found a great difference
in the effect resulting from the larger or smaller number of
pairs. Thus in the first experiments were obtained, with two
pairs, 53° of Breguet's helix; with four pairs, 75°; with six
pairs, 97°; and in the latter experiments were obtained, with
two pairs, from 1 1° to 12° ; and with six pairs, from 5° to 6°.
The following experiments were made with a slightly acid
solution, and show the rapidity with which the intensity of
the current diminishes according to the number of pairs.
At the instant of immersion two pairs gave 50° of Breguet's
helix, but at the expiration of a minute they only gave 30°;
fourteen pairs perfectly similar gave at the first instant 35°,
but at the end of a minute their effect was reduced to 10°.
When the solution had lost nearly all its acidity, two, four,
eight, and sixteen pairs, all gave 20° at the moment of im-
mersion, but their effect underwent a diminution, the quan-
tity and rapidity of which corresponded to the increase in the
number of pairs.

We proceed to inquire how the preceding results are to be
reconciled with our theory of the pile.

In all the experiments which have been described the sur-
face of the pairs remains constant, their number alone varies;
it is therefore evident, from what has been said, that the quan-
tity of -electricity produced at each of the poles is always the
same, but that the two electricities accumulated at the two
poles reunite in a larger or smaller proportion through the
pile. So soon as, by sufficiently increasing the number of the
pairs, we have succeeded in causing nearly the whole of the
two electricities to pass, in order to reunite, by way of the
conductor, in preference to that of the pile, the limit is at-
tained beyond which nothing is gained by adding to the num-
ber of pairs. It may therefore easily be seen why this limit
will be so much the sooner attained, in proportion as the
bodies interposed between the poles are better conductors,
and on the contrary the liquid of the pile a worse conductor.
But why, by increasing the number of pairs beyond the limit,
is the intensity of the current diminished ? It would appear
that neither diminution nor augmentation should be effected.
To explain this result it- must be observed that when the che-
mical action of the liquid upon the oxidable metal of the pair
is lively and prompt, it develops quantities of electricity upon
each pair, sufficiently considerable to be regarded as sensibly
equal in the same time, allowing that the small differences
which exist among them disappear when they are compared
to the absolute quantities themselves. The result therefore
is, that all the pairs being nearly of the same strength, an in-
crease in the number of pairs would not have any influence

296 M. De la Rive's Researches

upon the quantity of electricity circulating between the poles;
in fact, as we have seen, the intensity of the current is not di-
minished by increasing the number of pairs. But if the che-
mical action, instead of being lively, is weak, it cannot be
considered as developing, in the same instant, physically equal
quantities of electricity ; and the differences are more sensible
in proportion as the absolute quantity of electricity developed
is less. On the other hand, as the quantity of electricity in
circulation in each pair, and between the poles of the pile, is
determined by that disengaged by the most feeble pair, when
once the necessary limit has been exceeded, the more pairs
there are the more the number of cases is increased, in which
a feeble disengagement of electricity may take place in a given
time, and consequently the more diminished is the total quan-
tity of free electricity in circulation. To prevent this diminu-
tion there must always be an absolute simultaneity and equality
in the quantities of electricity disengaged, in the same instant,
by each pile, which is physically impossible, and that impos-
sibility increases as the number of the pairs becomes greater,
and the chemical action more feeble : all which is in perfect
agreement with experiment. It now remains to be shown
why, when the addition of a certain number of pairs has di-
minished the intensity of the current, a further addition, in-
stead of continuing to reduce it, can on the contrary terminate
the diminution, and cause the intensity again to increase.
When it was said, that the limit in the number of pairs most
favourable for obtaining a certain effect, was attained, the mo-
ment the current preferred the way of the conductor to that
of the pile, it was not to be understood by that, that no portion
of the current passed through the pile ; on the contrary, the
result of the manner in which the electricity is distributed be-
tween the conductors is, that a certain proportion of the elec-
tricities continues to reunite through the pile. But as this
proportion is very small, and as besides, when the number of
pairs is already great, the addition of others has no sensible
influence, the physical limit is attained, even when a propor-
tion of the two electricities still reunites through the pile.
However, if the number of pairs be considerably increased,
that part of the electricity which circulates through the pile is
in the end diminished, and consequently that which passes
through the conductor is in the same degree increased. A
great addition to the number of pairs is then a cause of aug-
mentation to the current; it is also, as has just been shown, a
cause of diminution. This augmentation and this diminution
do not follow the same law in relation to the number of pairs.
It is easy to conceive that as with a certain number of pairs
the augmentation preponderates over the diminution, so, on

into the Cause of Voltaic Electricity, 297

the contrary, with a different number, the diminution pre-
ponderates over the augmentation. The same cause produces
contrary effects with energies which acknowledge no regular
law; hence the alternations in the intensity of the current in
each particular case may depend upon a multitude of variable
circumstances ; such for example as the nature of the pairs,
their dimensions, the degree of acidity and conductibility of
the liquid employed, &c. The results of experiment are in
exact agreement with this.

We shall conclude our researches by inquiring into the re-
sult, if, instead of active pairs, inactive pairs be added to the pile,
that is, homogeneous metallic arcs of zinc, copper, or platina.
After I had enunciated the theory of the pile for the first time,
in 1828, M. Marianini thought a strong objection might be
raised against it from the influence of inactive pairs, which he
had studied carefully and in detail. Interposing between the
active pairs of a pile, diaphragms of copper, in a greater or
smaller number, he found that no augmentation in the tension
of the two poles resulted from it, and that this interposition
even diminished the chemical power of the pile in the decom-
position of water. But, said he, by means of these dia-
phragms the interior conductibility of the pile is diminished,
and consequently so much the more electricity should pass by
the conductor which unites its two poles. It is perfectly true
that whatever diminishes the conductibility of the pile should
augment the tension of its poles, and the quantity of electri-
city which circulates in the conductor which unites them ;
provided at the same time that the quantity of electricity de-
veloped by each pair is in no degree altered. Now the manner in
which M. Marianini diminishes the conductibility of the pile
is not included in these limits. The zinc and copper of the
pairs between which ha places his diaphragms are no longer
in the same condition as those of the other pairs; in fact the
liquid which separates them loses a great part of its conduct-
ing power by the interposition of these diaphragms ; hence the
positive electricity accumulated on the side of the zinc, and the
negative carried off" by the copper reunite in much less pro-
portion through this liquid, which is become a worse conduct-
or; it is exactly as if, instead of interposing diaphragms, a
liquid of much less conducting power had been substituted for
the liquid which separates the pairs. What is the result ?
That the free electricity of all the other pairs diminishes in the
same ratio as that of the pair which we have been considering,
so that if, on the one hand, the two electric principles accu-
mulated at the two poles reunite with less facility, on the other
hand they are developed in smaller quantity. With regard

Third Series, Vol. 11. No. 67. Sept, 1837. 2 Q

298 M. De la Rive's ^Researches

to tension, which is unconnected with the element of time,
since the condenser remains in contact with the pole an in-
determinate period, it may be conceived that the two effects
just noticed will nearly counterbalance each other, but it is
different with regard to the decompositions effected by the
current, and in general, with regard to all its dynamic effects,
for there is not sufficient time for the accumulation of the two
electric principles; and whatever diminishes the quantity of
free electricity disengaged by each pair in a given time, and
consequently at the two poles, diminishes the intensity of the
effects produced by this circulation. The only means by
which the conductibility of a pile may be diminished, without
altering the quantity of electricity which it produces, is, as
has been already said, by the addition of similar pairs.

In support of the explanation which has just been given, I
shall produce some experiments which I made with diaphragms
of different kinds. I had previously shown {Annates de Chim.
et de Phgs., Feb. 1825) and again in 1828 {Annates de Chim.
et de Phys.9 vol. xxxvii. p. 225.) that the diminution of con-
ductibility in a liquid which results from the interposition of a
metallic diaphragm, is reduced in the proportion that the dia-
phragm is attackable by the liquid. The following are the
results which I obtained.

A pile of seven elements, zinc and copper, the surfaces each
four inches square, charged with pure water, mixed with T1^
of nitric acid, gave 1 25° of Breguet's metallic helix. A dia-
phragm of zinc, interposed between any two pairs, reduced
the effect of the current to 100°; and a diaphragm of copper
reduced it to 70°. A pile of twenty pairs, similar to the pre-
ceding, but less strongly charged, gave 110° of the metallic
helix; a diaphragm of zinc produced no sensible diminution
in the intensity of the current ; a diaphragm of copper reduced
it to 100°. Lastly, employing diaphragms of platina, by
means of which I divided a certain quantity of concentrated
nitric acid into two or more parts, through which passed the
current of a strong pile composed of eight pairs, each two feet
square, and charged with a mixture of forty parts water, two
sulphuric acid, and one nitric acid, I always obtained, with
Breguet's metallic helix, the following results :

Exp. I. , Exp. II.

Number of Cent. Deg. of

diaphragms. the helix.

1 312°

2 170

3 75

4 12

5 0

Number of Cent. Deg. of
diaphragms. the helix.

1 220°

2

100

3

27

4

...... 5

5

0

into the Cause of Voltaic Electricity,

Exp. III.
Number of Cent. Deg. of Time for the evolution of

diaphragms. the helix. the same volume of gas.

0 38° 5"

1 3 25"

2 0 no effect.

From the first two experiments it may be seen in what an
enormous proportion the calorific intensity diminishes, ac-
cording to the increase in the number of diaphragms. In the
third experiment the current was made to pass at the same
time through the metallic helix, and an acid solution placed
in succession in its path. From this experiment it may be
seen that the interposition of a diaphragm which reduced to
T*7 the calorific intensity of the current, only reduced its
chemical power to 3-; a difference which shows the consi-
derable influence which the rapidity of the current exerts
over calorific power; as I have shown in a special memoir.
(Bibl. Univer. Jan. 1829.)

Summary. — We shall briefly recapitulate the results of these
researches.

1. The contact of two heterogeneous bodies without calo-
rific, mechanical, or chemical action, is not of itself a source of
electricity.

2. Chemical action, even the most feeble, develops a sen-
sible quantity of electricity ; but if this electricity be not
always perceptible, if especially its intensity be not always in
the ratio of the vivacity of the chemical action which pro-
duces it, it is essentially due to the immediate recomposition
of the two electricities which takes place upon the surface
attacked.

3. Entering upon the theory of the pile, the production,
and distribution of electricity in this apparatus, may be com-
pletely explained by the development of electricity resulting
from the chemical actions, and the neutralizations of the free
electricities which take place from pair to pair.

4. Attention being paid to the conductibility of the pile it-
self, and comparing it with that of the bodies placed between
its poles, all the dynamic effects of voltaic electricity, the cir-
cumstances which may modify the intensity of these effects,
and the apparent anomalies which they present may be easily
explained ; provided at the same time the principles above
stated are not lost sight of.

Ryde,Isle of Wight, 10th Aug., 1837.
[We shall notice in our next Number M. De la Rive's paper On the in-
fluence of heat on the passage of an electric current from a liquid into a
metal, and also his Researches on the Properties of Magneto-electric Cur-
rents.— Edit.]

2 Q 2

I

[ 300 ]

XXXIV. On the Affinity of some Fossil Scales of Fish from the
Lancashire Coal Measures with those of the recent Salmonidse.
By W. C. Williamson, Esq., Curator to the Manchester
Natural History Society* .

[With Figures : Plate II.]

N examining the roofstone of the black and white coal at
Peel near Worsley, I was fortunate enough to meet with
remains of fish, of a character sufficiently interesting to merit
this brief notice. This coal occupies a position about a thou-
sand yards from the top of the carboniferous series, and at
Peel presents in its immediate vicinity the following section :

Metal, 15 yards. Ft. In.

Coal 7 0

Metal, 4 yards.
White sandstone, 35 yards.
Metal, 44 vards.

"White" coal .' 2 5

Clav, one to seven vards.
" Black" coal \ 2 5

The shale in which the fish occur rests immediately upon
the " white coal." It is very compact, bituminous, and well
calculated for the preservation of minute characters. In this
shale I have already detected at least four species, belonging
to as many distinct genera, but at present would only call the
attention of ichthyologists to one, scales of which magnified
to thrice their natural size, are represented by the sketches
(PI. II.) figs. 4, 5, and 6. I have met with several specimens
of the fish to which they belong, but all are more or less in a
crushed condition. The scales vary in form from being nearly
circular to an oblong rhomboid, and on examining the scales
of recent Salmon id a?, I found that they had the same general
forms. A more minute examination exhibited a strong resem-
blance in the arrangement of the cycloid striae, which are
nearly as distinct in the fossil as in the recent species, especially
on the inferior surface of the scale, part of which is repre-
sented at fig. 5.

Fig. 1, 2, and 3 exhibit scales of the common salmon (after
the pearly enamel is removed) magnified to the same degree
as the fossil ones.

The only specimen I have yet found showing all the fins
is about 4 inches long. The head is crushed, but the body
and tail are nearly perfect. The anterior dorsal and the ven-

* Communicated by the Author.

Analyses of the Hydrates of Baryta and Strontia. 301

tral fins are placed opposite each other, as also are the anal
and what appears to be the posterior dorsal. Here a discre-
pancy exists. In recent Salmonidae, the latter fin is merely
a fleshy appendage, and not supported by rays. In the fossil
specimen the fin, though imperfect, exhibits traces of true rays.
Though this will prevent its being considered one of the Sal-
monidae, I know none other of the abdominal Malacopterygii
that have the same arrangement of the fins: this fact, com-
bined with the resemblance between the scales, which differ
only in the existence of radiating striae at one extremity of the
fossil, which do not exist on the recent ones, seems to indicate
a close affinity. The discovery of more complete specimens
may throw new light upon their nature.

XXXV. Analyses of the Hydrates of Baryta and Strontia.
By H. M. Noad, Esq., Lecturer on Chemistry.

To the Editors of the Philosophical Magazine and Journal.

Gentlemen,

/~\N looking over some of the back Numbers of your Ma-
VJ gazine, which have only lately come into my hands, I met
with a paper by Mr. J. D. Smith on the hydrates of barytes
and strontia, in which he seems to think that the previous de-
termination of [the quantity of water combined with these
metallic oxides, by Mr. Phillips, is not correct. On referring
to my journal, I found the results of an analysis of these hy-
drates by myself performed about two years ago, and having
some crystals of each at the bottom of two bottles in which
they had remained since that time, I determined to analyse
them again, with the greatest care, as my results did not
exactly correspond with those of Mr. Smith. As my recent
experiments coincide exactly with my former ones, perhaps
you will allow them to be inserted in your Journal, for the
inspection of Mr. Smith and others. I must observe that the
greatest care was taken to get the crystals perfectly dry by
pressure between folds of blotting-paper.

Bar. Sulph. of Bar. Bar. Water.

Exp. 1. 37-5 gave 26*75 = 17*56 + 19-94-

Exp. 2. SO* gave 21-5 = 14*11 + 15-89

Exp. 3. 26* gave 18*62 = 12*22 + 13*78

43*89 49*61

or 76*7 one equivalent of baryta combined with 8669 nearly
9 J equivalents of water.

302 Prof. Young's Analytical Investigation of

Thirty grains of crystals of strontia dissolved in hot water,
and precipitated by bicarbonate of potash, gave 16*5 of car-
bonate of strontia = 11 '56 strontia; a second thirty grains gave
precisely the same result : so

Stron. Stron. Water.

30 11*56 + 18*44, or, 51*8, one equivalent

of strontia combined with 82*62, rather more than 9 equiva-
lents of water.

Although these experiments do not agree with those either
of Mr. Phillips or Mr. Smith, their coincidence with each other
appears to show that these two metallic oxides do not behave
precisely the same with respect to water.

I am, Gentlemen, yours, &c,
Shawford near Bath, Aug. 18, 1837. Henry M. Noad.

XXXVI. Analytical Investigation of Professor Wallace's Pro-
perty of the Parabola. By J. R. Young, Esq., Professor of
Mathematics in Belfast College.*

IN the Philosophical Magazine for August 1836, a remark-
*- able property of the parabola, first established by Professor
Wallace, is made the subject of a communication from Mr.
Lubbock; in which communication that distinguished mathe-
matician has given a proof of the theorem upon the principles
of analytical geometry.

In a subsequent Number of the Magazine, that for January
1837, two other analytical investigations were given; one by
Mr. Greatheed of Trinity, and the other by Mr. Holditch of
Caius College, Cambridge; and a neat geometrical proof was
at the same time offered, differing but little from that of Pro-
fessor Wallace himself.

Ingenious and interesting as these several investigations are,
they can, I think, scarcely be regarded as more than mere
verifications, by analysis, of a previously known geometrical
truth ; in as much as they do not exhibit the steps by which
an analyst would be likely to be led to such a property, unless
it were anticipitated at the outset. It is certain also that no
analytical investigation hitherto given is comparable, on the
score of simplicity, with the geometrical proof; although it
would be premature to assert that analysis is incompetent to
furnish a proof equally simple and elegant.

The investigation which I here offer is remarkably easy ; it
differs essentially from those hitherto given, and will I think
bear a favourable comparison with the geometrical method.
« Communicated by the Author.

Professor Wallace's Property of the Parabola. 803

Referring to the diagram at page 33, in the Magazine for
January last, (vol. x.) let p be the origin of conjugate axes, p
being the point of contact of the tangent A P ; and let a line be
drawn from A, any point in this tangent, to the focus F. The
angle v contained between this line and a second tangent A Q,
will be obtained from the equations of the lines themselves by
help of the known relation,

(a — a') sin /3
tan v - l+aa! + ,a + ai) cos/3>

a and a representing the coefficients of x in those equations,
and j3 the inclination of the axes of reference. Let the co-
ordinates of the point of contact Q be xn yi ; then those of the

point A will be 0, ~ ; also, the point F is (w, — 2 m cos /3).

SE

Hence

2 in
Equation of A Q is y = (* + *,)

V
4r + 2 m cos Q

Equation of A F is y — ^ = — x

the tangent of the angle between them is by the preceding
formula

tant;

1-1-12 cos /3 + — cos/3-^cos/3-2cos2£

y{ y, 2 m

= \y>*m Zl = tan p.

S^+ -p- + 2cos/3lcos/3

Hence, since the angle § is equal to the angle F P A, it
follows that from whatever point in a tangent to a parabola
two lines be drawn? one to touch the curve, and the other to
the focus, the angle between them will be constant, and equal
to that between the fixed tangent and radius vector of its point
of contact. Thus F C subtends equal angles at A and B,
and therefore the points A, B, F, C are in the same circum-
ference.

It follows moreover that, B being upon the tangent R B,
F B P = F R B; and since FPB= FBR .\ PFB
= R F B, a property which must be previously established,
in the geometrical method, and of which I have never seen
any analytical proof.

SOif Mr. Watkins on Thermo-electricity.

In instituting a comparison between the geometrical and
analytical methods, in any given instance, account should of
course be taken of the amount of extraneous aid required for
the furtherance of each process. In analysis the truth is in
general evolved from the fundamental conditions, independ-
ently of subsidiary propositions beyond those which consti-
tute the first principles of the subject. In geometry, on the
contrary, we cannot arrive at the same conclusion without the
assistance of some neighbouring truth or chain of truths nearly
as remote from first principles as that to be established. It
may be proper to remark, that the expression — 2m cos /3,
for the ordinate of the focus, is deduced from the simplest
and most obvious considerations. The abscissa of the focus is
m, which is also the radius vector of the origin ; the ordinate
is thus the base of an isosceles triangle whose side is m, and
angle at the base /3 or the supplement of /3, accordingly as this
ordinate is negative or positive; its true value is therefore
that employed above.

Aug. 7, 1837.

XXXVII. On Thermo-electricity. By Mr. Francis
Watkins.

To the Editors of the Philosophical Magazine and Journal.
Gentlemen,
HPHAT species of electricity developed by the influence of
-"■ temperature first observed and made known to us by M.
Seebeck, in communications to the Academy of Berlin, in the
years 1821 and 1822, having latterly attracted increased at-
tention in this country, through the very interesting letter of
Professor Wheatstone, published in your last May number,
page 4? 15, and also from a valuable communication of Professor
Andrews, printed in the following June number, page 433, I
venture to trouble you with a few remarks, which I flatter
myself if admitted into your miscellany will not prove unac-
ceptable to many of your readers.

Professor Wheatstone's communication informs us that
Cav. Antinori obtained the spark from a thermo-electric pile
of Nobili's construction, consisting of twenty-five elements, by
employing an electro-dynamic helix and a temporary magnet,
while Professor Wheatstone employed a thermo-electric pile
of thirty-three elements of bismuth and antimony, formed
into a cylindrical bundle f of an inch in diameter and 1^- in
length : the poles of this pile were connected by means of two
thick wires, with a spiral of copper ribbon fifty feet in length

Mr. Watkins on Thermo-electricity* 305

and \\ inch broad, the coils being well insulated by brown
paper and silk.

We gather from these observations that Cav. Antinori em-
ployed an elongated coil as his electro-dynamic helix with
temporary magnets for eliciting the spark, while Professor
Wheatstone very judiciously resorted to the flat copper ribbon
coil, contrived and recommended for developing electricity
of feeble intensity by Professor Joseph Henry, of New Jersey
College, Princeton.

Cav. Antinori gives different lengths of his coils, and I
presume in all cases that he had the advantage of the in-
fluence of temporary magnets, for I have experimented with
short and slender coils surrounding different metals, wood,
&c, and failed entirely in obtaining sparks under these con-
ditions. When the same coils enveloped soft iron, then I got a
spark, even a feeble one, from a coil the wire of which was
only seven feet long and ¥\j of an inch in diameter.

With Professor Henry's flat coil I always show larger
sparks than with an elongated wire coil and large temporary
magnet, and the snapping noise of the spark is certainly more
discernible. Hence I feel warranted in advising those who
desire to show the thermo-electric spark in its fullest effect
to use the flat ribbon coil of Professor Henry, in preference
to the elongated wire coil and temporary magnet, at the same
time permit me to add that those who possess a fair-sized
electro-magnet can exhibit the spark of a thermo-pile with
tolerable efficiency.

My first attempt to repeat Professor Wheatstone's experi-
ments was with a very small and slender thermo-pile of thirty
pairs of elements three inches long, and a Henry's coil, and I
fully succeeded in eliciting the spark, A few days afterwards
in an interview I had with the Professor he was so kind as to
inform me that a thermo-electric pile of one inch square
plates in his possession had afforded him sparks of an in-
creased size to those obtained from the small pile described
in his communication to you. Hence I adopted the sugges-
tion of employing large metallic elements.

I have recently made many experiments with thermo-piles of
various-sized and different-formed metallic elements, and dif-
ferent numbers of alternations, and find that the powers ex-
erted by the metallic elements of a pile are referrible to the
same law which governs the development of electricity de-
rived from other sources of excitation, namely, that quantity
is increased by mass.

The spark has hitherto been obtained from the surface of
mercury, a metal at all times to be avoided in an apparatus

Third Series. Vol. 11. No. 67. Sept. 1837. 2 R

306 Mr. Watkins on Thermo-electricity.

in which metals like antimony ^and bismuth joined together by
soft solder form a part. I arrange one of my extremities of
the pile of strong sheet copper, cut like a comb, and covered
with soft solder (the latter is a plan, I believe first suggested
by Dr. Hare, to obviate the trouble of amalgamating at every
experiment), and when the moveable extremity of my Henry's
coil is passed over the comb, and the thermo-electric pile in
action, splendid sparks are seen every time the moving part
of the coil breaks the circuit by leaving a tooth of the comb.
I have used stellar-formed wheels, vibrating pendulums, &c,
&c, to break contact, and all give beautiful sparks and shocks
when desired. When a small steel file forms the moving
part, splendid scintillations are noticed, and to do away with
amalgamation, soft solder, &c, 1 frequently employ an old
plan of silver against silver for making and breaking contact;
the spark thus developed is vivid, and, as we might expect, of
a beautiful green hue; but it must be confessed that no sparks
are so brilliant as those from the surface of mercury, for we
can seldom obtain other metallic surfaces equally clean.

I desire here to record what I believe to be novel, that on
the 27th of last June, with a thermo-electric pile, consisting
of thirty pairs of bismuth and antimony, 1^ in. square and \
thickr with the radiation of red hot iron at one extremity and
ice at the other extremity, a soft iron electro- magnet, under
the inductive influence of the electricity thus generated, sup-
ported ninety-eight pounds weight, the most powerful thermo-
electric magnet I have heard of; but it must be observed that
this is no maximum, for whoever employs a larger elementary
battery will no doubt obtain greater effects, not only as re-
gards inductive influence on soft iron, but all others in which
the influence of temperature may be exerted.

There is an ample field for investigation open for those
who have leisure on this subject. Who knows but hereafter
electro-magnetism may be employed as a prime mover, and
that a thermo-pile may be the exciting cause?

By adopting Professor Henry's method of giving the shock
with his flat ribbon coil, from a single pair of voltaic plates, I
have succeeded in obtaining in a marked and decided manner
the physiological effects on the tongue, with the thermo-pile
of thirty pairs of elements.

The spaces in your excellent journal are far too valuable to
be occupied by lengthened descriptions of the various-formed
metallic elements that I have used and that may be employed,
and even of those that I have found best suited for the experi-
mental inquirer and public demonstrator. Nor dare I venture
to occupy your pages with long details of the results arrived

Geological Society. 307

at by different modes of applying increasing or decreasing
temperature to the pile. All that now need be said on that
head is that I have thermo-electric piles varying from fifteen
to thirty pairs of metallic elements, which give brilliant sparks
by simply pouring hot water on one end, while the other end
is at the temperature of the atmosphere. Again, sparks are
exhibited by the same piles when the temperature is reduced
at one end by the aid of ice, and the other end at the tempe-
rature of the surrounding air.

Of course, as has been noticed before, the effects will be
greatly enhanced by still greater difference of temperature
being produced at the opposite end of the pile.

I remain, Gentlemen, yours, &c,
5, Charing Cross. FRAN CIS WATKI NS.

XXXVIII. Proceedings of Learned Societies.

GEOLOGICAL SOCIETY.

May 31, " tf^N certain areas of elevation and subsidence in
1837. ^~J the Pacific and Indian oceans, as deduced from

the study of Coral Formations ;" by Charles Darwin, Esq., F.G.S.
The author commenced by observing on some of the most re-
markable points in the structure of Lagoon islands. He then pro-
ceeded to show that the lamelliform corals, the only efficient agents
in forming a reef, do not grow at any great depths j and that be-
yond twelve fathoms thebottom generally consists of calcareous sand,
or of masses of dead coral rock. As long as Lagoon islands were
considered the only difficulty to be solved, the belief that corals
constructed their habitations (or speaking more correctly, their
skeletons), on the crests of submarine craters, was both plausible and
very ingenious ; although the immense size, sinuous outline, and
great number, must have startled any one who adopted this theory.
Mr. Darwin remarked that a class of reefs which he calls «' encir-
cling" are quite, if not more, extraordinary. These form a ring
round mountainous islands, at the distance of two and three miles
from the shore ; rising on the outside from a profoundly deep ocean,
and separated from the land by a channel, frequently about 200
and sometimes 300 feet deep. This structure as observed by Balbi
resembles a lagoon, or an atoll, surrounding another island. In
this case it is impossible, on account of the nature of the central
mass, to consider the reef as based on an external crater, or on any
accumulation of sediment; for such reefs encircle the submarine
prolongation of islands, as well as the islands themselves. Of this
case New Caledonia presents an extraordinary instance, the double
line of reef extending 140 miles beyond the island. Again the Bar-
rier reef, running for nearly 1000 miles parallel to the North- East
coast of Australia, and including a wide and deep arm of the sea,
forms a third class, and is the grandest and most extraordinary coral
formation in the world.

2 R2

308 Geological Society : — Mr. Darwin on areas of

The reef itself in the three classes, encircling, barrier and lagoon,
is most closely similar; the difference entirely lying in the absence
or presence of neighbouring land, and the relative position which
the reefs bear to it. The author particularly points out one diffi-
culty in understanding the structure in the barrier and encircling
classes, namely, that the reef extends so far from the shore, that a
line drawn perpendicularly from its outer edge down to the solid
rock on which the reef must be based, very far exceeds that small
limit at which corals can grow. A distinct class of reefs however
exists, which the author calls " fringing reefs," which extend only
so far from the shore, that there is no difficulty in understanding
their growth. The theory which Mr. Darwin then offered, so as to
include every kind of structure, is simply that as the land with the
attached reefs subsides very gradually from the action of subterra-
nean causes, the coral building polypi soon again raise their solid
masses to the level of the water ; but not so with the land : each
inch lost is irreclaimably gone : — as the whole gradually sinks, the
water gains foot by foot on the shore, till the last and highest peak
is finally submerged. Before explaining this view in detail, the
author offered some considerations on the probability of general
subsidences, — such as the small portion of land in the Pacific, where
many causes tend to its production, an argument first suggested by
Mr. Lyell, and the extreme difficulty (with the knowledge that co-
rals grow at but limited depths) in explaining the existence of a
vast number of reefs on one level, without we grant subsidence, so
that one mountain top should be submerged after another 5 the
zoophytes always bringing up their stony masses to the surface of
the water. Subsidence being thus rendered almost necessary, it was
shown by the aid of sections, that a simple fringing reef would thus
necessarily be converted by the upward growth of the coral into
one of the encircling order, and this finally, by the disappearance
through the agency of the same movement of the central land, into
a lagoon island. In the same manner a reef skirting a shore would
be changed into a barrier extending parallel to, but at some di-
stance from, the mainland.

Mr. Darwin then showed, that there existed every intermediate
form between a simple well characterized encircling reef, and a la-
goon island ; that New Caledonia supplied a link between encircling
and barrier reefs ; that the different reefs produced by thesame order
of movement were always in juxtaposition, of which the Australian
barrier associated with encircled islets and true lagoons, affords a
good example. He then proceeded to show that within the lagoon
of Keeling Island, proofs of subsidence might be deduced from
many falling trees and a ruined storehouse ; these movements ap-
pearing to take place at the period of bad earthquakes, which like-
wise affect Sumatra, 600 miles distant. It was thence inferred as
probable, that as Sumatra rises, (of which proofs are well known to
exist,) the other end of the lever sinks down ; Keeling Island thus
acting as an index of the movement of the bottom of the Indian
Ocean. Again at Vanikoro, where the structure indicates accord-

elevation and subsidence in the Pacific and Indian Oceans. 309

ing to the theory recent subsidence, violent earthquakes are known
lately to have occurred.

Theauthor then removedan apparent objection to the theory, name-
ly, that subsidence would form a disc of coral but not a cup-shaped
mass or lagoon, by showing that the corals which grow in tranquil
water are very different from those on the outside, and less effective ;
and that as the basin becomes shallower they are subject to various
causes of injury. The lagoon nevertheless is constantly filling up to
theheight of lowest water spring tides, (the utmost possible limit of
living coral,) and in that state it long remains, for no means exist to
complete the work. Mr. Darwin then proceeded to the main object
of the paper, in showing that as continental elevations act over wide
areas, so might we suppose continental subsidences would do, and
in conformity to these views, that the Pacific and Indian seas could
be divided into symmetrical areas of the two kinds ; the one sink-
ing, as deduced from the presence of encircling and barrier reefs,
and lagoon islands, and the other rising, as known from uplifted
shells and corals, and skirting reefs. The absence of lagoon islands
in certain wide tracts, such as in both the West and East Indies,
Red Sea, &c, was thus easily explained, for proofs of recent
elevation are there abundant. In a like manner, in very many cases
where islands are only fringed with reefs, which according to the
theory had not been subsiding, actual proofs of elevation were ad-
duced. Mr. Darwin remarked that, excepting on the theory of the
configuration of reefs being determined by the order of movement,
the circumstance that certain classes which are characteristic and
universal in some parts of the sea, being never found in others, is
quite anomalous, and has never been attempted to be explained.

Mr. Darwin then pointed out the above areas both in the Pacific
and Indian Oceans, and deduced the following as the principal re-
sults. 1st. That linear spaces of great extent are undergoing move-
ments of an astonishing uniformity, and that the bands of elevation
and subsidence alternate. 2. From an extended examination, that
the points of eruption all fall on the areas of elevation. The author
insisted on the importance of this law, as thus affording some means
of speculating, wherever volcanic rocks occur, on the changes of
level even during ancient geological periods. 3. That certain coral
formations acting as monuments over subsided land, the geogra-
phical distribution of organic beings (as consequent on geological
changes as laid down by Mr. LyelT) is elucidated, by the discovery
of former centres whence the germs could be disseminated. 4.
That some degree of light might thus be thrown on the question,
whether certain groups of living beings peculiar to small spots are
the remnants of a former large population, or a new one springing
into existence. Lastly, when beholding more than a hemisphere,
divided into symmetrical areas, which within a limited period of time
have undergone certain known movements, we obtain some insight
into the system by which the crust of the globe is modified during
the endless cycle of changes.

A letter to Charles Lyell,Esq. u On some changes of level which
have taken place during the historical period in Denmark" j by G.

3 1 0 Geological Society : — Dr. Forcham mer on Changes

Forchammer, Phil. Doct. Copenhagen, Foreign Member of the
Society.

The author referring to the observations of Mr. Lyell and of Mr.
Nilsson, on the unequal elevations of Sweden and subsidences of
Scania ; as proving that not only does elevation go on at a different
rate, but that motion takes place in opposite directions, adduces, as
instances of similar phenomena, the islands of Saltholm and of Born-
holm as well as the Danish coast of the Sound. The island of
Saltholm opposite to Copenhagen, and hardly five feet above the
level of the Sound, being mentioned from the thirteenth century
as a source of income to the chapter of Roeskilde; must have been
elevated at a slower rate than Bornholm, which rises about one foot
in a century ; for if it were now to sink only two feet a very small
portion of the island would be left.

On the Danish coast however of the Sound, six miles to the north
of Copenhagen, a well characterized beach is observed, six feet
above sea-level ; hence the author infers that the change of level on
the Danish, proceeds in a different proportion from that on the Swe-
dish shore; which he ascribes to the slight earthquakes so frequently
felt in Sweden, but never observed in Denmark.

With respect to the Danish island of Bornholm, the author ob-
serves, that its whole eastern shore is composed of a granitic rock,
rising abruptly out of the sea, and covered to the height of 250 feet
by a stiff loamy soil, containing numerous fragments of the slates
and limestones of the transition formation ,• of which the calcareous
specimens may easily be traced to the island of Gothland. From these
facts, and the absence of the plutonic rocks so frequent in the boul-
der formation of Denmark, and from the absence of this clayey
loam on the western side of the granitic ridge; he conceives that it
is the result of a violent inundation from the north-east of the Bal-
tic. The effects of this may be seen both in the form of the Da-
nish coast, and in the deposits of sand which cover a great part of
Denmark ; but which have been evidently swept away from the
more easterly beds of the boulder formation.

At a height of about forty feet may be observed the first beach
formed on Bornholm : wherever by the receding of the granitic
mountains from the coast, small bays were formed, these became
choaked up by the granitic pebbles of the beach, and small ponds
were thus formed and separated from the sea ; and in the course
of ages became filled up with peat. This peat moss is separated
from the sea by a beach of small breadth, ten feet high, sloping at
an angle of 15°, and abutting on a horizontal plain, 160 feet in
breadth, formed entirely of beach stones. Beyond this is a second
plain, 100 feet broad, which slopes to the sea at an angle of 9° to 10°,
and is followed by the present beach sloping at an angle of 12° to
13°. The pebbles of all are similar in size, and composed of the
same granite as the solid rock.

The author, referring to the existence on the sloping beach of
graves, marked only by a ring of stones, and to the testimony of an-
tiquaries, that it was the custom to bury Christians on the beach,
where the land and sea separated, about the year 900 ; obtains ma-

of Level in Denmark, during the Historical Period. 311

terials for a rough calculation as to the time when this beach was
formed. The continuous but very slow elevation of the island, as
shown by the sloping beach, would thus have been about one foot
in a century ; and the beginning of the regular elevation of the
island about 1600 years ago. Previous to this there must have
been a long and perfectly quiet time, during which the horizon-
tal beach was formed. Supposing the rise of the island and the
lateral addition to the sloping beach to have been quite regular, and
the lateral extension of the horizontal beach to have been equally
uniform, we require for its formation a period of 2500 years.
This would carry back the sudden elevation of the island of ten feet,
marked by the narrow and abrupt, as well as highest beach, which
the author thinks may have been caused by a great earthquake, to
a period of 4000 years from the present time.

The author also informs us that over all Denmark, Sleswig, and
Holstein, shells of the German ocean of the present day, may be
found sometimes at considerable elevations above the level of the sea.
Thus not far from Bornhoveland Holstein, at a height which exceeds
150 feet, a bed of fossils and pebbles occurs, containing Cardium
edule, Littorinalittorea, Buccinum undatum, Ostrea edidis; the latter
shell is however smaller than that now living on the coast, but agrees
with that found fossil in the raised beds of recent marine shells of
England. Subsidences must also have occurred, as between the
island of Romoe and the shores of the kingdom of Sleswig, a sub-
marine forest (said to be of fir) is found at nine feet below the pre-
sent high water mark.

The author also calls the attention of geologists to the traces of
an inundation of about sixty feet above the present high water mark,
on the islands of the western shores of Sleswig; and which appears
to have taken place since these were inhabited by man, since Tumuli
are found partly destroyed by the inundation.

A paper " On the Physical Structure of Devonshire, and on the
subdivisions and geological relations of its old stratified deposits ;"
by the Rev. Adam Sedgwick, F.G.S., & R.S., Woodwardian Pro-
fessor in the University of Cambridge; and Roderick Impey Mur-
chison, Esq., V.P.G.S., F.R.S., was commenced.

June 14. — The paper by Prof. Sedgwick and Mr. Murchison, on
Devonshire begun at the last meeting, was concluded.

Chap. I. — After a few preliminary remarks the authors proceed to
describe the general structure of Devonshire, which they consider as
divided into rive distinct geological regions.

1. The first region extends through the most eastern portions of
the county, and is principally occupied by formations of new red
sandstone and green sand.

2. The second region (which is prolonged into the north-west
corner of Somersetshire) occupies the most northern portions of the
county, being bounded to the north and west by the sea, to the
cast by the plains of new red sandstone connected with the Vale of
Taunton, and to the south by a line which stretches across the
county in a direction almost east by south, commencing at the coast
on the south side of Barnstaple, and thence ranging north of South

3 1 2 Geological Society : — Prof. Sedgwick arid Mr. Murchison

Molton, Bampton, «tid Holcombe Rogos, to the plain of the new red
sandstone.

3. The third region stretches across the county ; being bounded
to the north by the line above indicated, and to the south by a line
which, commencing at Boss Castle on the coast of Cornwall, ranges
to the south side of Launceston, and thence in a somewhat devious
course to the northern edgeof Dartmoor. This southern boundary also
descends considerably on the east side of Dartmoor, inclosing some
of the country near Chudleigh. The region thus bounded is composed
of one great formation (occupying more than a third of the whole
county), to which the authors give the name of Culm Measures.

4. The fourth region includes all the country occupied by slate
rocks, extending from the granite of Dartmoor and the Culm Mea-
sures to the south coast of Devon.

5. The last region is occupied by the granitic rocks, which extend
through the whole of Dartmoor.

Of the regions above enumerated few notices are offered respect-
ing the first, but the other four are described in considerable de-
tail, and in the above order.

Chap. II. — Succession of deposits between the north coast of
Devon and the Culm Measures.

The authors commence with a description of the rocks in the north-
west corner of Somerset, which are identical in structure with a part
of the region here described. They divide them into two great
groups; the lower group abounding in a coarse arenaceous strong-
bedded rock (grey wacke), often of a red colour, and sometimes vari-
egated like specimens of new and old red sandstone j the upper
containing some beds of like character, but abounding morein rotten
thin-bedded slates (shillot), in which some portions are highly cal-
careous, and pass into irregular bands of limestone, and contain en-
crinital stems and obscure traces of organic remains. They then go
on to describe the successive groups occupying the region of
North Devon, and by help of natural sections (from the coast to the
north boundary of the Culm Measures) prove, that there is an enor-
mously thick ascending series of rocks, interrupted however by nu-
merous contortions and by a great anticlinal line, ranging with the
strike of the beds, about west by north or west-north-west. This
line runs into the sea a little south-west of Linton, and in conse-
quence one of the great groups is repeated twice over ; first on the
coast north-east of Linton, and secondly on the coast extending from
the Valley of Rocks to Comb Martin. From these facts it follows
that the lowest rocks in North Devon are in the denudation of the
Lynn river, which nearly defines the position of the anticlinal region ;
and from the south side of that river to the Culm Measures is an
ascending section, interrupted only by local contortions. They then
describe the successive groups of the ascending section.

1. Lowest group. Valley of the Rocks and gorge above Linton.

The structure of this group is very varied. Some beds coarse and
arenaceous; others passinginto a fineglossy schist, sometimes chloritic.
The finer beds often contain innumerable casts of organic remains,
and impressions of shells are not unfrequent in the coarser arenaceous

on the Physical Structure of Devonshire. 3 1 3

bands. Near the fossiliferous schists the beds become calcareous,
and in one place pass into an impure limestone : many of the beds
have a slaty cleavage transverse to the stratification, and cutting through
the non-calcareous portions and the lines of organic remains. The
thickness of this group is great, but its base is not exposed.

2. The preceding division passes by almost insensiblegradations into
the great red arenaceous groups already mentioned. The beds of green-
ish slate, shillot, &c, become quite subordinate, and the whole cha-
racter of the formation is derived from the coarse arenaceous beds,
sometimes passing into a siliceous conglomerate. These coarser
beds are commonly red or variegated j among them, however, are grey
and greenish grey beds, the colours, as might be expected, being-
inconstant. Oxide of iron traverses some portions of these rocks in
thin veins, and that mineral abounds so much in some of the beds,
that they have been regularly quarried (e. g. near Comb Martin
and to the south-east of Porlock), and smelted in the iron foundries.
The slaty cleavage transverse to the bedding almost disappears among
these rocks, but they are much intersected by joints, some quite ir-
regular in bearing; but two sets, one ranging with the beds and the
other transverse to these (respectively called strike joints and dip
joints), are described to be of common occurrence. The authors found
no organic remains in this group, but they have been found, though
very rarely, in some of the shillots and finer schistose masses, which
are subordinate to the coarser red siliceous sandstones. Its whole
thickness is computed (especially from the coast section west of the
Valley of Rocks) to be five or six thousand feet.

3. The next group differs greatly from the former, in having compa-
ratively few of the coarse siliceous sandstones, wanting the red
colour ; abounding in bands of rotten slate, sometimes like dark in-
durated slate, but more frequently greenish and chloritic, and
commonly exhibiting a cleavage distinct from the stratification.
It also contains many calcareous bands (in some places not less than
eight or nine), which occasionally swell out into masses of limestone,
and numerous organic remains, not however generally well pre-
served. Its thickness is estimated at two or three thousand feet,
and notwithstanding some contortions, it dips on the whole to-
wards the south : its strike, like that of the beds near the coast,
is about east-south-east and west-north-west. . This formation
is traced far into the interior, and is identified with the calcareous
system flanking the Quantock Hills.

4. The next group has the same strike as the preceding, and is of
enormous thickness, though not so great as might at first sight be
imagined from its breadth or the surface of the country and its high
inclination, as many parts of it are violently contorted. The authors
divide it into two portions, the lower abounding in fine glossy chlo-
ritic schist, much contorted, and having a true cleavage transverse
to the bed, and generally presenting a succession of parallel fissile
planes, dipping at a high angle to the south j the upper beds con-
taining similar masses alternating with coarse, thick, arenaceous
bands, some of which resemble the rocks of the second group of the
section.

Third Series. Vol. 11. No. 67. Sept. 1837. 2 S

314? Geological Society: — Prof. Sedgwick and Mr. Murchison

5. The last group in this part of the ascending section commences
on the south side of a line drawn from Baggy Point on the coast in
the direction of the strata, or east and by south. It is composed of
arenaceous flag stones and soft earthy slates, alternating with harder
and coarser bands : it conforms to the mineral type commonly found
in the lowest part of the Silurian system, has abundance of organic re-
mains, and is in parts calcareous ; but the fossils are often ill pre-
served and partially destroyed by the cleavage passing through them.
The group is several thousand feet thick, and though much contorted
(the anticlinal and synclinal lines coinciding with the strike) at
length dips regularly under the base of the Culm Measures. Such is
the succession in this portion of the section across Devon. Three di-
stinct groups of calcareous and fossiliferous slates, separated from
each other by deposits of vast thickness, very little calcareous, and
almost without fossils. The base of the series is not exposed, and
the last ascending term conforming to the type, and probably of the
date of the lowest portion of the Silurian system.

These last-mentioned rocks much resemble the lowest Silurian
strata of Pembrokeshire, which also graduate into the Cambrian
system, and in which the specific character of the shells is often ob-
literated or obscured by transverse lines of slaty cleavage. Impres-
sions of crinoidal stems abound ; trilobites occur but rarely, and
among the shells are two or three which cannot be distinguished from
lower Silurian fossils. As however no fixed line of demarcation has
yet been established between the lower Silurian and upper Cambrian
groups, their zoological contents being, as far as we know, very simi-
lar, the place of this member of the Devon series must, for the present,
be considered provisional.

The sandstones of this division are in one district pretty abun-
dantly charged with impressions of plants, for an acquaintance with
which the authors express their obligations to Major Harding and the
Rev. D. Williams, both of whom have sent collections to the Geolo-
gical Society. Professor Lindley is of opinion that none of these
plants are similar to those described in the sequel as common to the
Culm Measures : some resemble decorticated Lepidodendra, and
others Sternbergia?. One specimen resembles Calamities Voltzii of
the Terrain d'anthracite inferieur (Voltz).

The authors conclude their remarks on the whole region by some
account of joints. %

Dip joints and strike joints abound in all the groups, and though
not constant in their inclination are generally inclined at a high
angle, separating the great masses into rhombohedral solids. The
transverse cleavage planes are not parallel to joints, and are regarded
by the authors as forming a distinct class of phenomena.

Chap. III. — Deposits of the fourth region.

The natural groups are determined by help of sections ; one from
Dartmoor to the coast of Torbay ; another from Torbay to Start
Point ; and a third from Dartmoor to Bolt Head. In describing
these sections the authors enter on many details not given in this
place, and from a review of the whole division, the following groups,
beginning, as before, with the lowest.

on the Physical Structure of Devonshire. 315

1. An ill-defined group near the granite, supposed to be meta-
morphic.

2. A great complex slate group, with two subordinate calcareous
zones, in some places swelling out to a great thickness. The lower
calcareous mass (called the Ashburton bands) pass into Cornwall,
and range through the greater part of the county ; the upper are re-
presented in the most striking form by the Plymouth and Torbay
limestone.

3. A coarse red arenaceous group, like the second group of the
preceding chapter, immediately surmounts the Plymouth and Torbay
limestones, and like them is of enormous thickness.

4. A great schistose deposit, striking with the other rocks in the
southern region, nearly east and west. The prevailing dip is south,
and it is not much contorted, but at length it is reversed to the north,
being thrown off by an anomalous mass of chlorite and mica slate
which occupies the promontories of Start Point and Bolt Head.

5. Mica and chlorite slate j — the relation of which to the other part
of the series is unknown.

The authors then contrast the two regions above described. In
the southern, trap rocks appear occasionally j in the northern they
are wanting. The slaty cleavage so common in the northern is want-
ing in the southern region, though the rocks are in many places so
fissile as to make good roofing slate, but in such cases they exfoliate
parallel to the stratification.

In comparing the two regions they endeavour, first, to identify the
calcareous group of Linton (No. 1 of chapter ii.) with the calcareous
bands (No. 2) of this chapter. Secondly, to identify the coarse red
group of North Devon (No. 2, chap, ii.) with No. 3 of South Devon.
Lastly, to identify the great slate group of South Devon (No. 4) with
Nos. 3 and 4 of North Devon. The absence of the calcareous band
of North Devon (No. 3) is not considered to throw much difficulty in
the way of this classification. By way of general conclusion, the au-
thors consider all the above groups of North and South Devon to be
netverth&n the rocks of Snowdon and central Cumberland (lowest part
of the Cambrian system), and older (with a very limited exception in
North Devon) than the Silurian system : they therefore place them
in the upper and middle parts of the Cambrian system, from the more
ordinary appearance of which they are chiefly distinguished by the
greater abundance of calcareous matter and fossils.

The organic remains of the lower strata of South Devon are
indeed so very dissimilar from those of the Silurian system that they
cannot have been formed in that aera. These fossils will be de-
scribed and published*.

Chap. IV. — Culmiferous series of the third region.

The authors first describe many sections to prove that the Culm
Measures occupy a great trough, and dip away on both sides from

* The Rev. — Hennah has placed his rich and valuable collection of Ply-
mouth fossils at the disposal of the authors. Mr. Austen, F.G.S., has also
contributed largely from the neighbourhood of Newton Bushel. Major
Harding, F.G.S., and the Rev. D. Williams, F.G.S., have been the most
zealous collectors in North Devon.

2S2

316 Geological Society : — Prof.K Sedgwick and Mr. Murchison

the other rocks with which they are in contact ; hence whatever may
be their age, the Culm Measures are the newest stratified deposits de-
scribed in this memoir. Along their northern boundary they rest on the
highest group described in Chap, ii j and on their southern boundary they
partly rest on the granite and partly on the oldest slate rocks of Devon
and Cornwall. Hence they cannot form (whatever be the mineralo-
gical appearance) a true passage into the different schistose inasses on
which they rest. Again, they are overlaid by no rocks older than the
new red sandstone ; their age can therefore only be determined by
their structure and organic remains.

The authors then describe sections of the Culm series in great detail,
showing its enormous thickness and endless contortions ; the anti-
clinal lines generally ranging with the strike, or nearly east and west.

For convenience, the series is divided into two groups.

The lower is made up of dark carbonaceous shales, sandstones,
micaceous and siliceous flagstones, and calcareous shale, here and
there containing subordinate beds of black limestone. All the Wa-
vellite of Devon is found in this lower group. These beds are beau-
tifully brought out both along the northern and southern boundaries.

The upper group is made up of an indefinite alternation of shales
and sandstones, variable in structure, but generally rather thin-
bedded : commonly, the shales are considerably indurated and re-
semble '{ grey wacke," but in other places they are soft and earthy
like ordinary coal-shale.

The sandstone bands vary much in texture j there are large quar-
ries of them not to be distinguished from coarse coal grits j very
rarely they puton a conglomerate form -, mostfrequently they are close-
grained, but even in that respect do not differ much from the grit-
stone bands in the carboniferous system of a part of South Wales.
Pyrites abounds and ironstone is occasionally found associated with
the shale and sandstone.

Carbonaceous stains and impressions of plants occur in many
parts of this great formation, and thin laminae of anthracite are com-
mon in both the upper and lower group ; but large masses of
anthracite and beds fit to work for use are only found in the upper.
The authors then describe the Culm works in the neigh-
bourhood of Bideford, where three beds have been worked : the best
is stated to average nearly four feet in thickness, while in some places
it swells out to twenty feet, and in others contracts almost to nothing.

The plants differ essentially from those found in the older rocks,
but are all identical with those species which are most abundant in
the coal-fields of the central counties of England and in the South
Welsh basin, among which Cyperites bicarinaia, Neuropteris cordata,
N. gigantea, Pecopteris lonchitica, and P. abbreviata are perhaps the
most widely distributed. In their lithological aspect also, and in
containing vast quantities of small sedge-like vegetables, these
culm-bearing strata of Devon are undistinguishable from the coal
measures of Pembrokeshire. No animal remains have been disco-
vered in them, nor in the underlying sandstone (millstone grit), in
which negative features these rocks further coincide with those of the
Pembrokeshire coal field.

on the Physical Structure of Devonshire. 317

The subjacent black limestone has indeed no exact parallel in En-
gland, its organic remains being for the most part peculiar and un-
described ; they are all apparently of marine origin. Among them are
two genera of large, transversely ovate bivalve shells, one of which
has a strong resemblance to a Possidonia of the Yoredale series
of the Mountain Limestone (Phillips). Another is like, but not
identical with Gervillia laminosa (Phillips). Chambered shells also
occur, some of which are considered to be Goniatites, a genus which
has never yet been found in the Silurian or older rocks, but is most
characteristic of the carboniferous system.

In mineral characters this black limestone approaches closely to the
calp of Ireland, which though now clearly acknowledged to be a part
of the carboniferous group, is nearly devoid of characteristic fossils.
As the whole formation is of enormous thickness and exhibits no
plants with distinct specific characters in its lower parts, and as the
black limestone contains no species of shell absolutely identical with
fossils of the mountain limestone, the authors consider the base line of
the series as in a position not yet completely ascertained j though they
distinctly prove that it never passes down into the older rocks on which
it rests. As however, the upper group contains a fine series of
vegetable fossils, everyone of which agrees specifically with true car-
boniferous plants, they have no hesitation in placing these culm mea-
sures on the same parallel with the true carboniferous series of Great
Britain. The evidence of fossils is in favour of the conclusion, and
the sections, instead of opposing, confirm it j in short the culm-bearing
beds of Devon are identical with the coal measures of Pembrokeshire
both in mineral character and organic remains.
Chap. V. — Granite of Dartmoor, &c.

The jointed structure of this rock is described in detail, and the joints
are shown to agree in their direction with those described by Messrs.
Fox, Enys, and other geologists in Cornwall. The authors also con-
firm a remark of Dr. Boase that the same master joints often affect the
granite and bedded rocks near it: they show that the granite has in
some places broken through the stratified formations without much
changing their strike ; hence the successive members of the culm
measures abut against the granite on the north-west side of Dart-
moor. In all such cases, following the beds along the line of strike,
they are changed in structure as they approach the granite, the sili-
ceous bands being converted into quartz rock, the shales into
Lydian stone, felspar, porphyry, &c. They regard thesefacts as perfect
proofs of the metamorphic nature of the rocks in contact with the
granite of Devon. Lastly, they describe granite veins and elvan
dykes as traversing the Culm Measures.

The conclusion is, that no rocks in Devon or Cornwall are older
than the Upper or Middle Cambrian j that a magnificent develop-
ment of the Upper Cambrian terminates in the ascending order about
the base of the Silurian system ; that these rocks are surmounted by
an immense culmiferous trough, the upper portion of which is identical
in fossils with the upper division of our coal measures; and that the
granite is posterior to all these, but probably anterior to the new red
sandstone.

318 Geological Society : — Messrs. Murchison and Strickland

A paper was then communicated, ° On the upper formations of the
New Red System in Gloucestershire, Worcestershire and Warwick-
shire, showing that the Red(Saliferous) marls with an included band
of sandstone, represent the Keuper or Marnes irisees, and that the
underlying sandstone of Ombersley, Bromsgrove and Warwick, is
part of the ' Bunter Sandstein,' or ' Gres bigarre' of foreign geo-
logists;'' by Roderick Impey Murchison, F.R.S., V.P.G.S., and
Hugh E. Strickland, Esq., F.G.S.

In previous communications* Mr. Murchison has shown, that the
system of New Red Sandstone in the central counties of England
is divisible into four formations. 1. Marls xuith salt and gypsum, and
one included band of sandstone, (Foreign Equiv. Keuper or marnes
irisees.) 2. Quartzose Sandstones, (Bunter Sandstein, or Gres bi-
garre.) 3. Calcareous Conglomerate, representing the magnesian
limestone or dolomitic conglomerate, (Zechstein, &c.) 4. Lower
Nexa Red Sandstone, (Rothe todte liegende.)

The object of the present communication is to mark, with precision,
the distinctive characters of the two upper formations of this system,
and to point out how the one can be separated from the other over
a wide area, by stratigraphical, lithological, and zoological distinc-
tions.

The rocks are described in descending order.

Red and Green Marls and Sandstone, (Keuper.) — This for-
mation includes all the variegated marls which lie between the
lowest beds of Lias, and the uppermost strata of the underlying
formation of sandstone.

The highest of these marls graduate into the lias, are occasion-
ally gypseous, and at a depth of about 200 feet beneath the lias,
are underlaid by a peculiar sandstone, which appears to have escaped
the notice of former observers.

Tracing this rock from the borders of Gloucestershire, through
Worcestershire into Warwickshire, the authors show, by various
sections at Burg Hill, Ripple, Wallsfarm, Inkberrow, Hervington,
and Shrawley Common, that this band, which never exceeds forty
feet in thickness, invariably occupies the same stratigraphical
position. It is a thin-bedded, hardish, quartzose sandstone, usually
of whitish colour, but sometimes tinted light green and red ; the
grains of sand being frequently cemented by decomposed felspar,
and the beds separated by thin way-boards of greenish marl. The
courses of stone are of very irregular extension, thinning out amid
the marls. The lower strata are sometimes, (as at Inkberrow,) suf-
ficiently thick-bedded to be used as building stones, but the flag-like
character prevails (tombstones, &c).

This thin-bedded sandstone is characterized throughout its course,
by a small bivalve shell, somewhat resembling a Cyrena in form,
but the genus has not been determined. Ichthyodorulites occur
and seem to belong to the genus Hybodus (Agassiz) : also teeth of
fishes have been observedf.

* Proceedings, vol. i, p. 471 ; vol. ii, p. 115.

t It is proposed to call the Ichthyodorulite Ht/bodus Keuperi.

on the Upper Formations of the New Bed System. 319

At Shrawley Common, near Warwick, the surface of some of the
beds is impressed with foot-marks of an animal, probably a crocodile
or saurian, having feet with four claws.

The marls beneath the sandstone are of great thickness, and
have been sunk through at Stoke Prior, near Droitwich, to a depth of
near 600 feet. Besides gypsum they contain masses of rock salt,
and are the sources of brine springs. In piercing these marls no
bed of sandstone has ever been met with, and no fossils have been
observed. This great marly formation, comprising the fossil-
iferous sandstone, is compared with the Keuper of Alsace and Sua-
bia and proved to be its equivalent. The discovery of ichtbyo-
dorulites of a genus so abundant in the lower lias, but of an un-
described species, is considered by the authors to be a good zoolo-
gical confirmation of the age of the sandstone, as indicating an
approach to the types which characterize the lower lias.

New Red Sandstone, (Bunter Sandstein, Gres bigarre). — The up-
per beds of this arenaceous formation, rising from beneath the marls,
are usually light coloured j the tints of the sandstone varying
from dingy yellow, to white and grey, greenish grey and red.
These light-coloured sandstones are occasionally covered by thin
courses of red sandstone, which graduate into the overlying marl $ but
they invariably pass down (sometimes by alternations) into the great
red sandstone of the central counties, and are thus inseparable from
that formation. This order is clearly seen at Ombersley, Hadley,
Elmley Lovett, and Bromsgrove, in Worcestershire. This sand-
stone is lithologically distinguishable from the overlying Keuper
sandstone in being softer, much thicker bedded, and more mica-
ceous, though like that rock, some of the upper strata are wedge-
shaped and inosculate with marl. This lower rock is the same as
that described by Mr. Murchison, at Hawkstone and Grinshill in
Shropshire, in which localities it is one of the best building stones
in the kingdom.

In its range from Ombersley, by Hadley to Elmley Lovett,
and again near Bromsgrove, the sandstone contains many plants,
usually in a state approaching to charcoal, the jet black colour
forming a striking contrast to the light-coloured matrix.

Among these plants, the greater part of which are too imperfect
to be identified, Professor Lindley has, however, recognized the
strobilus of a species of Echinostachys ; (E. oblongus) figured by
M. Ad. Brongniart as peculiar to the gres bigarre ; a portion of a
flabelliform palm leaf; parts of dicotyledonous stems with their
bark ; a broad leaf of some monocotyledon, and a species, probably
of Convallirites, (Brongn).

As these fossils bear no affinity to the well-known plants of the
Keuper, but have on the contrary a strong resemblance to the
Flora of the H Gres bigarre, " offering in one instance a specific
identification with a vegetable peculiar to that formation, the au-
thors have no doubt that this light-coloured sandstone of Worces-
tershire forms part of the same deposit.

By sections extending from Warwick to the north-west, the sand-
stone of Guy's Cliff and Leamington is shown to be of the same

320 Intelligence and Miscellaneous Articles,

age as that of Bromsgrove, being also a soft, light-coloured,
slightly micaceous and thick-bedded sandstone : and rising up
immediately from beneath the red marl, it cannot be confounded
with the upper or Keuper sandstone, which at Rowington Tunnel
and Shrawley Common is seen to overlie the great mass of red
marl in manner before described.

Portions of bones of saurians abound in what the workmen call
the dirt bed of the Warwick sandstone ; but the fragments are so
mutilated, and generally in such a decomposed state, that they can-
not be identified. Plants also occur, but from a similar cause their
recognition is very difficult. In addition to the fossils collected
by Dr. Buckland, the authors have found teeth of fishes.

As no attempt has been made to prove that the animal found in
Guy's Cliffis of the same species as either of the Phytosauri of the
Keuper of Wirtemberg ; the authors throw it out as a probable
conjecture, that if ever accurately determined, it will prove of the
same species as one of the saurians in the bunter sandstein of the
continent.

The sandstone of Warwick is therefore identified with the rock
of Bromsgrove and Ombersley in Worcestershire, and Hawkstone
and Grinshill in Shropshire, which has been shown to be a portion
of the red sandstone representing the gres bigarre or bunter sand-
stein.

Although assiduous search has been made to discover a calca-
reous stratum between the two formations above described, which
might represent the " Muschelkalk," no traces of such a rock have
been detected except in Shropshire, where Mr. Murchison has noticed
a band of very impure limestone, occupying the same interme-
diate position, hut as yet no organic remains have been observed in
it.

On the whole the authors conclude, that the most exact parallel,
exists between the upper formations of the new red system of
England, and those of a large part of France, where the muschel-
kalk being also absent, the marnes irrisees and gres bigarre pass
into each other in the manner above described*.

XXXIX. Intelligence and Miscellaneous Articles.

CARBOV1NATE OF POTASH.

MM. Dumas and Peligot by passing a current of dry carbonic
acid into a solution of barytes in pyroxylic spirit (I* esprit de
bois) obtained carbo-methytate of barytes. The production of this
compound led them to suppose that the preparation of the carbovinates
would be attended with but little difficulty. When, however, this
idea was put in practice, they were interrupted by the discovery
that although pyroxylic spirit dissolves anhydrous barytes, yet al-
cohol does not possess this property ; they therefore tried whether
the use of an alcoholic solution of ammonia would not be attended
with success. By passing a current of dry carbonic acid through

• See the writings of M. Dufrenoy and M. Elie de Beaumont. (Memoire
pour servir a une de scription geologique de la France, vol. i. p. 313 et seq.)

Intelligence and Miscellaneous Articles, 321

a solution of anhydrous ammonia in absolute alcohol a salt was ob-
tained, but it did not possess the properties of carbovinate of am-
monia. They then tried the action of dry carbonic acid on a solu-
tion of potash which had been heated to redness, in absolute alcohol.
As the operation is attended with the evolution of heat, it is neces-
sary that it should proceed slowly and the vessel be kept cold in
which it is conducted. The crystalline substance formed by this
action soon becomes so abundant as to solidify the solution ; a
volume of anhydrous aether equal to that of the solution must then
be added, and thrown upon a filter. By washing the product with
anhydrous aether there remains a mixture of carbonate, bicarbonate,
and carbovinate of potash. To separate the last salt the mixture
must be washed with absolute alcohol, which dissolves it, and anhy-
drous aether added to the filtered solution, which reprecipitates it.
This liquor immediately filtered and dried in vacuo affords pure car-
bovinate of potash. The analysis of this salt indicates exactly the
following formula :

KO, OO; OH*, C«6f, HO.

This salt is in shining scales. It decomposes by heat into car-
bonic acid, an inflammable gas, an eethereal fluid, carbonate of
potash, and charcoal. Dissolved in water it is rapidly converted
into bicarbonate of potash. Dissolved in weak alcohol, or even if
it contains only slight traces of water it suffers the same decompo-
sition, and deposits the bicarbonate in shining plates resembling the
carbovinate, consisting, however, of

KO, C*0*j HO, c«w

This rapid and easy conversion of carbovinate into bicarbonate
of potash affords but slight hopes of the possibility of isolating the
acid, but it is evident that such an acid does exist ; and its pro-
perties may be interesting as relative to the theory of fermentation.
—V Institute April 19, 1837.

CONVERSION OF IRON INTO PLUMBAGO BY SEA-WATER.

M. Deslongchamps has found lying near La Hogue, where the
naval battle was fought, some cannon balls, which although they do
not appear externally to have undergone any change, yet have lost
two-thirds of their weight and may be cut with a knife like a black-
lead pencil : they contain no iron in the metallic state, and exert
no influence on the magnetic needle. — Jour, de Chim. Med. Fevr.
1837.

ON A COMBINATION OF THE ANHYDROUS SULPHURIC AND SUL-
PHUROUS ACIDS.

By treating anhydrous sulphuric acid by gaseous sulphurous acid
also anhydrous, M. Henri Rose has obtained a liquid possessing an
odour resembling sulphurous acid, and which completely volatilizes
by exposure to the atmosphere, with the evolution of powerful fumes.
This liquid is a compound of the anhydrous sulphuric and sulphurous

Third Series. Vol. 11. No. 67. Sept. 1837. 2 T

322 Intelligence and Miscellaneous Articles.

acids in atomic proportions. Its preparation is not attended with
success unless certain precautions are taken. It is particularly ne-
cessary to avoid every trace of moisture, for if it be present, this
compound decomposes very rapidly even when it is formed, and if not
already formed, should one of its constituents contain the least
moisture, the experiment will not succeed.

M. Rose therefore conducts the gaseous sulphurous acid into a
cooled receiver, then passes it througli a tube of at least four feet
long and filled with chloride of calcium which has been recently
fused. This tube communicates with a glass vessel containing the
anhydrous sulphuric acid. This vessel is cooled to about the free-
zing point of water, but not below it, in order that the product may
not contain any free liquid sulphurous acid. As soon as a certain
quantity of liquid is formed it must be poured off from the excess
of solid sulphuric acid into a small and well-stopped glass vessel.
The chloride of calcium in the tube will serve for the preparation
of only a small quantity of this compound, and must be re-heated to
redness before it is again used.

The liquid thus obtained exhales when in contact with the air ex-
tremely powerful fumes resembling sulphurous acid. It volatilizes rea-
dily, the residue being a very small quantity of liquid sulphuric acid.
If a very small portion of water be put in contact with this liquid, it
immediately produces a lively effervescence with a disengagement of
sulphurous acid. Dry ammoniacal gas passed into this liquid, a mixture
of anhydrous sulphate and sulphite of ammonia is obtained of a yel-
lowish colour, and soluble in water : its solution on the addition of hy-
drochloric acid disengages sulphuric acid, but does not precipitate
sulphur, which only takes place when the liquid is boiled. A solution
of nitrate of silver affords a precipitate, which is at first white, be-
comes yellow, brown, and finally black, particularly by ebullition.
M. Rose in the analysis of this compound has ascertained the precise
quantity of sulphuric acid, but not that of sulphurous acid, although
he endeavoured to determine the latter in many different modes ; he
was therefore obliged to calculate the quantity of this acid from the
loss. The results of the analysis of four distinct preparations are
placed according to their age, for it is found that the compound
contains more sulphuric acid when it is not analysed immediately
after its preparation, a little sulphurous acid being separated ; and
on the contrary, more sulphurous acid in the opposite case, when
it may contain a little free sulphurous acid.

The Proportion of

Weight of the Compound

Weight of Sulphate

Sulphuric Acid con-

analysed.

of Barytes obtained.

tained in 160 parts
of this Compound.

1 . 0-529 gram.

1-122 gram.

72-9

2. 0-955

1-945

70-

3. 1-274

2-554

68-91

4. 2-550

5-021

67-68

Thus this combination does not contain, as the author supposed
before it was analysed, sulphurous and sulphuric acid in the pro-
portions necessary for the formation of anhydrous hyposulphuric

Intelligence and Miscellaneous Articles. 323

acid (S-f-S) but two atoms of sulphuric acid united to an atom of
sulphurous acid (2S-f-S), which by calculation gives in a hundred

Parts Sulphurous acid 28-58

Sulphuric acid 71*42

100-00

As the sulphurous acid is that which exists in the least proportion
in this combination, it may be considered as the basic constituent,
and in this point of view the compound is a neutral sulphate(bi-sul-
phate ?) in which the sulphuric acid contains thrice as much oxygen
as the base. — Journal de Pharmacie, March 1837.

ON GALLIC ACID. BY M. ROBIQUET.

M. Robiquet remarks that before M. Pelouze had published his
work on tannin and gallic acid, it was generally admitted that the
acid was ready formed in the gall nut, and it was far from being
supposed, as attempted to be shown by this chemist, that gallic acid
was entirely derived from the tannin. M. Robiquet, after stating
some difficulties in admitting this opinion, observes, that whether
the acid pre-exists or not in the gall nut, it is certain that a large
quantity separates independently of contact with the air or with
oxygen, and without any action, if indeed there be one, which
occasions the evolution of any gas.

M. Robiquet then details experiments which show that tannin
does not yield much above half its weight of gallic acid ; and he
observes that there is great disproportion between the time required
to convert pure tannin into gallic acid and that required for the en-
tire gall nut. In the latter case a month is sufficient in favourable
weather to complete the action. He is therefore of opinion that
the gall nut contains other principles, which facilitate the operation
by acting as a kind of ferment, and M. Robiquet supposes that the
gum, or rather mucilage, which may be separated by water from the
residue after the action of aether upon the gall nut, performs this
office.

Following out the opinion formerly stated by M. Chevreul, that
tannin may be a compound of which gallic acid is one of the ele-
ments, M. Robiquet examined whether this idea was probable, and
the results were the following : M. Pelouze had inferred from his
analysis of tannin that it consisted of C18 H18 O12. M.Liebig has
since remarked that the analysis agrees better with C18 H16 Oi2, and
preferred the latter as more easily explaining the conversion of tan-
nin into gallic acid. M. Pelouze nevertheless retained the first for-
mula, and M. Robiquet adopts it as agreeing better with his new view
of the subject. Thus, this formula C l8 H18 0»2 ==* (C? H6 O + H* O)
+ H2 C4 represents 2 atoms of crystallized gallic acid, plus 1 atom
of a carburetted hydrogen of the same composition as benzin. The
formula adopted by M. Liebig will equally apply to other changes.
Thus, the 3 atoms of tannin are equivalent to 6 atoms of gallic acid,
plus 2 atoms of dry pyrogallic acid, 3 (C18 H1<5012)= O4 H48 036=
6 (C? H6 O*) + 2 (C6 H6 O) ; or still better, by admitting that tan-

2T2

324 Intelligence and Miscellaneous Articles,

nin may absorb an atom of water, there would result gallic and acetic
acid. In fact, O H'6 012 + 0H°- = 2 (C H6 O) + C4 H6 0s re-
presents 2 atoms of gallic acid and 1 atom of acetic acid. — Journal
de Chimie Medicate, Mai 1837.

SPONTANEOUS COMBUSTION OF LINSEED OIL AFTER ITS BE-
COMING DRY.

The heating of linseed oil when soaking into soft vegetable fibrous
or porous matters, has been several times brought into public no-
tice ; but we have not observed this effect when the oil has become
dry and hard.

A manufacturer at Plymouth had occasion, two or three years
since, to grind some red lead in oil, and a cask of it was set aside
till it had become hard, and consequently useless, which soon hap-
pens to that mixture, red lead being a rapid " dryer." Some months
since, being annoyed at this cask lying about the warehouse, he
ordered it to be knocked to pieces and the contents powdered, to
see if anything could be made of it. This being done in the even-
ing, and the powder put into a box, he was surprised in the morning
by a smell of fire, and after searching the warehouse over, perceived
smoke issuing from this box ; water was thrown in, and when all
was cold the contents were turned out. The bottom of the box was
found charred, the matter next it brown and partly reduced, and so
to about the centre of the mass, from whence it shaded off through
chocolate colour to the surface, which retained its redness, but was
clotted hard together like all the rest.

The same manufacturer has occasion for large quantities of oiled
paper, which when quite dry and no longer adhesive to the touch,
he has sometimes put together in piles, but has been obliged to se-
parate them again on account of the heat generated, which has been
such as to threaten ignition.

August 5, 1837.

PROCESS FOR INK DEVOID OF FREE ACID. BY R. HARE, M.D.

PROFESSOR OF CHEMISTRY IN THE UNIVERSITY OF PENNSYLVANIA.*

Writing ink is usually constituted of the tanno-gallate of iron and
a portion of sulphuric acid, which had existed in the copperas or sul-
phate of iron employed as one of its ingredients, the tanno-gallate
being suspended and the acid dissolved in the water. This free acid
is injurious to iron pens. Dr. Hare has observed that when an in-
fusion of galls is kept over finery cinder till saturated, it forms a
beautiful ink, in which of course there is no free acid.

This ink is rather more prone to precipitate than that made with
sulphate of iron, and this propensity is not counteracted by the ad-
dition of gum arabic. But, on the other hand, it has the advantage
of being easily suspended again by agitation, not forming any con-
crete matter insusceptible, like common ink grounds, of that distri-
bution in water which is necessary to good ink The tanno-gallate

* The above and three following notices have been communicated by the
author.

Intelligence and Miscellaneous Articles. 325

of iron when obtained from a filtered infusion of galls and finery
cinder, as above described, on being evaporated to the consistency
of thick molasses, gum arabic in due proportion having been pre-
viously added, forms a pigment which might, it is conceived, super-
sede Indian ink. When completely dried it glistens like jet with or
without the gum.

This tanno-gallate of iron only requires to be dried and ignited
at a low red heat, in order to be converted into a pyrophorus. A
few years ago Dr. Hare ascertained that, by a similar ignition in close
vessels, cyanoferrite of iron, the Prussian blue of commerce, gave
a pyrophorus. But as the pure cyano-ferrite of iron, resulting from
the addition of the ferro-prussiate of potash, more properly the cy-
ano-ferrite of potassium, to a ferruginous solution did not form a
pyrophorus ; he was led to believe that the presence of sulphate of
alumine in the commercial Prussian blue was the source of the differ-
ence, probably by being converted into a sulphide of aluminium, or
potassium.

The production of a pyrophorus from the tanno-gallate proves
that iron and carbon, when in a state of minute division, are capable,
by ignition in close vessels, of acquiring that property of sponta-
neous combustibility which entitles the body which possesses it to
be called a pyrophorus.

In truth these results are consistent with some facts mentioned
by Berzelius, as having been ascertained by Mitcherlich, respecting
the spontaneous combustibility of iron, reduced from the state of
magnetic oxide to that of the pure metal in an extreme state of di-
vision. They are also consistent with the spontaneous combusti-
bility of the residue resulting from the ignition of the oxalate of iron
at a red heat.

RAPID CONGELATION OF WATER BY MEANS OF HYDRIC (SUL-
PHURIC) JETHER AND CONCENTRATED SULPHURIC ACID, &C.
BY R. HARE, M.D.

In freezing water by the vaporization of hydric, commonly called
sulphuric, aether, there is much labour in pumping, and the aetherial
vapour condensing in the pump, disqualifies it for nice experiments
until cleansed. Dr. Hare finds that the interposition of sulphuric acid
lessens the requisite labour, and protects the pump. By means of
a globe or bottle with two tubulures, and a glass funnel with a cock,
the acid being in the globe, the water in a retort, and the aether in
the funnel, while the two former are exhausted, on allowing the
aether to descend upon the water, the congelation of this liquid is
instantaneous.

It has been ascertained by the same chemist, that a permanent
self-regulating reservoir of chlorine may be made by means of the
apparatus heretofore used by him for nitric oxide, substituting for
the materials used in that case, manganese in lumps and concen-
trated muriatic acid.

In one case, Dr. Hare, doubting the purity of the gas, from some

326 Intelligence and Miscellaneous Articles,

indications, among others the want of the usual degree of colour,
in order to test it exposed leaves of a thin metal called Dutch
gold leaf, to a jet of this gas, as he had previously done repeatedly,
without any ill consequence; to his astonishment an explosion took
place, which burst the apparatus and produced a detonaiion as loud
as if one of the explosive compounds of chlorine and oxygen had
been generated. Yet the only agents employed were peroxide of
manganese and chloro-hydric (muriatic) acid. It was the deficiency
of intensity in the colour which led him to test it by means of the
leaf metal. The colour of the protoxide is known to be of a deeper
yellow than that of chlorine.

SYNTHESIS OF AMMONIA. BY R. HARE, M.D.

Understanding that the synthesis of ammonia had been effected
by the reaction between nitric oxide and hydrogen promoted by
the presence of platina sponge, Dr. Hare, having no knowledge of
the process as performed in Europe, succeeded in the following
manner in the attainment of that highly interesting result.

Two volumes of nitric oxide and five of hydrogen were intro-
duced into a bell glass with a perforated neck furnished with a cap
and cock. At the bottom of a tubulated glass retort, capable of
holding about four ounce measures of water, a small heap of platina
sponge was made. A leaden pipe communicating with the cock of
the bell at one end, and at the other terminating in a copper or
glass tube, having a bore about as large as a knitting-needle, was
passed through the tubulure so that the orifice of the tube was
nearly in contact with the metallic heap. The pipe was made to
form an air-tight juncture where it entered the tubulure, and the
beak of the retort was recurved so as to be beneath the surface of
some water in a wine-glass. The bell being depressed below the
surface of the water in the pneumatic cistern, the cock was opened
as as to allow the gaseous mixture to enter the retort and displace
the atmospheric air. As soon as this was known to have taken place,
by the disappearance of the red fumes resulting from the reaction
of the nitric oxide and atmospheric oxygen, the gas being still al-
lowed to pass slowly in bubbles through the water in the wine-glass,
an incandescent coal was held near the part of the retort supporting
the sponge. The metal being thus heated became ignited, and
fumes appeared in the cavity of the retort. An absorption of the
water in the wine-glass followed, which was however immediately
checked by a supply of gas from the bell sufficient to cause the
bubbling to recommence and continue. Under these circumstances
the water in the wine-glass acquired the odour of ammonia, and gave
with copper the well known blue colour.

In a subsequent experiment a small lump of the sponge was se-
cured in a coil of platina wire and fastened to the tube so as to re-
ceive the jet of the mixed gases.

Dr. Hare published the fact, some years since, that asbestus
soaked in a solution of chloride of platinum and ignited, would cause
the inflammation of hydrogen with oxygen. He finds asbestus, si-

Intelligence and Miscellaneous Articles. 827

milarly prepared, to produce the synthesis of ammonia, either when
substituted for the sponge, in the experiment above described, or
carried red hot from a fire and passed into a bell glass containing
the mixture over mercury.

In fact a piece of charcoal soaked in a solution of chloride of pla-
tinum, (choroplatinic acid,) produced effects analogous to the pla-
tinated asbestus.

To produce platinated asbestus, it was found sufficient to dip it
in liquid chloride of platinum, and then subject the mass to a red heat
in a common fire.

ROTATORY MULTIPLIER. BY R. HARE, M.D.

Dr. Hare has contrived a rotatory multiplier in the following way:
Just as the needle, in oscillating, reaches its appropriate position
in the meridian, by means of two pins proceeding from it perpendi-
cularly so as to enter two mercurial globules, it completes a circuit
through the coil ; one end of which terminates in one of the glo-
bules. The other end of the coil of the multiplier communicates
with one pole of a galvanic pair, of which the other pole communi-
cates with the other globule. The needle is thus subjected to an
impulse which causes it to revolve until it receives another impulse
by the same process repeated. Each revolution therefore causes
an impulse which is productive of a succeeding revolution so long as
the galvanic reaction is sustained.

The construction was subsequently improved by employing two
coils of copper wire of equal length, separated by paper and varnish,
one being wound over the other. They were so arranged that the
needle receives two impulses in each revolution, one as above de-
scribed, the other when its north pole points to the south. Again,
two needles associated so as to form a cross are made to complete
a circuit every fourth of a revolution, and thus to receive four im-
pulses in one revolution.

METEOROLOGICAL OBSERVATIONS FOR JULY 1837.

Chiswick. — July 1. Cloudy : fine: clear and cold at night. 2, 3. Very

dry. 4— 12. Very fine. 13. Overcast. 14. Cloudy and fine, heavy
showers. 15. Showery. 16. Very fine. 17, 18. Cloudy and fine.

19. Very fine. 20. Fine. 21 — 26. Very fine. 27, 28. Very hot and
sultry. 29. Heavy rain : excessively boisterous in the afternoon.

30. Cloudy: showery. 31. Very fine: showery.

Boston. — July 1. Cloudy. 2, 3. Fine. 4—7. Cloudy. 8. Fine.

9. Cloudy. 10, 11. Fine. 12. Cloudy. 13. Cloudy: rain with thunder
and lightning p.m. 14. Cloudy: rain early a.m. 15. Cloudy: rain early
a.m.: rain p.m. with thunder and lightning. 16, 17. Fine : rain p.m.

18. Cloudy: rain p.m. 19. Fine. 20. Cloudy : rain a.m. and p.m.

21 -25. Cloudy. 26. Fine : rain a.m. 27. Cloudy. 28. Rain.

29. Rain and stormy. 30. Cloudy and stormy. 81. Fine: rain with

thunder and lightning p.m.

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T II E

LONDON and EDINBURGH
PHILOSOPHICAL MAGAZINE

AND

JOURNAL OF SCIENCE.

♦

[THIRD SERIES.]

OCTOBER 1837.

XL. On the prepared or peculiar Voltaic Condition of Iron.
By Sir John F. W. Herschel, K.G.H., M.A., F.R.S.*

IN the Number of the Annates for the month of March of
the present year, (1833, vol. lii. p. 288,) which I have re-
cently received, I find a remark of M. Braconnot upon the
manner in which concentrated nitric acid acts, when brought
into contact with iron, which brings to my recollection some
experiments made several years ago upon the same subject,
presenting particularities sufficiently curious to merit a closer
examination. I am at present unable to resume my researches,
but I think that an account of them will not be uninteresting
to your readers, and that it may induce one of them, per-
haps M. Braconnot himself, to study in detail the very re-
markable phaenomena of the action in question, and to con-
nect them with the usual laws of chemical action.

M. Braconnot says, " filings, or if they be prefered, plates of
iron immersed in concentrated nitric acid, do not experience
the slightest alteration, and retain all their metallic lustre, so
that they are thus preserved from rust. If the same acid be
made to boil upon these plates, and it be afterwards supersa-
turated with ammonia, it scarcely deposits a few insignificant
flocks of oxide of iron." The following are my own observa-
tions. (I extract the experiments from a journal dated Au-
gust 1825.)

* From the Annates de Ckimie et de Physique, vol. liv. p. 87, being the
paper alluded to by Mr. Faraday in Lond. and Edinb. Phil. Mag., vol. ix.
p. 122.; and now inserted to complete the series of papers on the subject
to which it relates.

Third Series. Vol.11. No. 68. Oct. 1837. 2 U

330 Sir John F. W. Herschel on the Prepared

If a piece of soft iron wire, well brightened, be immersed
in nitric acid of the density 1*399, the iron instantly becomes
brown, and an effervescence more or less lively takes place,
attended with the disengagement of red vapours ; but this
effervescence only lasts a few moments. It very soon ceases,
when the iron immediately recovers its metallic lustre, and
afterwards remains tranquil and intact at the bottom of the
acid for any length of time that may be desired.

Iron thus treated, (which for the sake of brevity, I shall
in future call prepared iron,) may be withdrawn from the
acid and exposed to the air, or immersed in pure water or
in ammonia, without by these means regaining the property
of being attacked by nitric acid. In its prepared state it may
be touched (gently) either in the air or in acid, with gold,
silver, platina, mercury, glass, and several other substances
without destroying this state. But if its surface be rubbed
with force, so as to establish an intimate contact; if, for ex-
ample, it be scraped with the edge of a piece of glass, upon
a glass plate, its state of preparation is then destroyed, and if
it be again immersed in the acid, the effervescence followed
by total inaction again occurs, and the metallic lustre re-
appears : in a word, this is a complete renewal of the prepared
state. If, on the other hand, prepared iron be touched
either with copper, zinc, tin, bismuth, antimony, lead or iron
not prepared, when either in the air, water or acid, the pre-
pared state is destroyed, and the action of the acid commences
again with effervescence, &c, as usual.

If a rather long piece of iron wire, prepared and moistened
with acid, be touched with copper at one of its extremities
while it is held suspended in the air over a glass plate, the
surface may be seen to become brown, not instantaneously,
and all over at once, but successively and by a movement, so
to speak, propagated (with rapidity certainly) from the ex-
tremity touched to the other extremity. When, in the pro-
gress of this embrowning, the limit of the brown colour reaches
a drop of acid suspended at an inflection of the wire, effer-
vescence and the complete decomposition of the drop of acid
take place. But if a wire immersed in the acid be thus
touched, the action is instantaneous throughout its whole
length.

If these experiments be performed in a capsule containing
only a small quantity of acid, and many times repeated, the
acid becomes incapable of producing the prepared state in
the iron. This effect appears to arise partly from the heat
evolved, and partly from the presence of nitrous gas ; for
having impregnated pure acid with this gas until it acquired

or peculiar Voltaic Condition of Iron, 33 1

a green colour, it was found incapable of communicating the
prepared state to iron. A piece of iron, immersed in acid
thus impregnated, continued to produce a lively effervescence
until it was entirely destroyed.

A piece of prepared iron was immersed in a solution of
nitrate of copper. No precipitate resulted, but when it was
touched in the solution with a piece of copper, the surface
became instantly covered with a thick layer of metallic copper.

Between those states of the acid, in which it is capable and
incapable of preparing iron, several intermediate states inter-
vene, in which the preparation of it is effected with more and
more difficulty, and the effervescence lasts longer and longer.
In these intermediate stales the following remarkable pheno-
menon sometimes occurs : the action ceases for an instant,
and then recommences, and that several times in succession,
and with convulsive intermittences, which sometimes succeed
each other at intervals of -J to f of a second, sometimes with
an extraordinary rapidity, so that they cannot be counted.
When they are slow, it is easy to see that the cessation of the
action is propagated from one extremity of the wire to the
other, though a reason cannot always be assigned why it
ceases at one extremity rather than at the other.

It often happens that the iron, without acting with vivacity,
does not cease to have a brown surface, to colour the sur-
rounding acid, and to give off gaseous bubbles: this slow action
may be arrested immediately in a singular manner, by with-
drawing the iron from the acid, holding it for an instant in the
air, and then letting it fall suddenly with a little shock. In
half a second afterwards it seldom fails to shine with all its
brilliancy.

The same effect may be produced with greater certainty, if,
without withdrawing the iron from the acid, it be touched with
a thin plate of platina. The contact of the platina, and, under
certain circumstances that of silver also, exercises an inverse
influence to that of zinc, &c. &c, in the production of the
prepared state, or in its preservation when it exists. Thus,
when operating in a capsule of platina, or upon a plate of that
metal placed at the bottom of a porcelain capsule, the pre-
paration of iron may be effected, not only with concentrated
acid, but with dilute acid, even when diluted with an equal
quantity of water. With a larger proportion of water the
preparation of the iron is no longer possible, even when there
is an intimate contact of the platina; but if a portion of acid
be added, the iron resumes its brilliancy and becomes pre-
pared.

Once prepared, the iron resists perfectly the action of an

2 U2

332 Sir J. F. W. Herschel on the. Voltaic Condition of Iron.

acid diluted to the same, or even to a greater extent; which
proves that these phenomena are owing, not merely to the
absence of the water necessary to hold the nitrate of iron in
solution, but rather to a certain permanent electrical state of
the surface of the metal. This mode of considering the
subject is confirmed by the following experiments.

A piece of iron wire was heated, and a small zone of wax
placed around the middle of it to divide it into two pro-
tions. The wire being immersed in the concentrated acid,
the action ceased at the same moment upon each half, and
upon touching one of its extremities with copper the action
was renewed in each simultaneously. The prepared state
being again established, the iron was withdrawn by a glass rod
attached to the wax, and one of its extremities was touched
while it was in the air. The action commenced as usual at
the extremity touched, and was extended through half of the
wire, but was then stopped by the wax, so that one half was
brown, while the other retained its metallic lustre.

A piece of iron, bent into an arc and divided as I have de-
scribed by wax, was prepared, and then two- thirds of its length
withdrawn from the acid, thus leaving the greater part of one
half of it, A, still immersed. The other half (B) while thus
in the air was touched with copper, when the action was pro-
pagated to the wax, where it stopped. The extremity B was
then quickly lowered until it touched the surface of the acid ;
the action commenced immediately in the portion A, which
was immersed, and which had hitherto preserved its lustre.

Prepared iron resists the action of the acid, when at a tem-
perature insupportable to the hand, but not at the tempera-
ture of ebullition. When it is let fall into very hot acid, it
resists for a few instants, and then begins to cause a violent
effervescence. I have never found that iron could be
submitted to the action of boiling nitric acid without oxida-
tion, as is remarked by M. Braconnot, but perhaps the acid
which he employed was more concentrated than mine. On
the other hand I have found it impossible to make acid, of the
density of 1*399, either cold or at the temperature of ebulli-
tion, act upon softened steel (acier recnit), or even upon those
plates of steel which are employed for watch-springs. It may
be kept boiling upon the plates for any length of time, without
producing the least effect. But a circumstance, which to me
appears very singular, is that a wholly different effect is pro-
duced upon steel which has received the highest temper, so
as completely to resist the file, it being attacked with extreme
violence by the hot acid, and even with considerable facility
by cold acid. But when the acid is cold the steel is easily

J. C. Marquart's Report of the Progress of photochemistry. 333

prepared and becomes brown, in the same manner as iron
when touched with zinc, but slowly, and, so to speak, with
resistance. But if it be prepared and touched alternately
several times in succession, it finally becomes subject to in-
termittences of action, becomes heated, and emits torrents of
gas, without there being any possibility of calming the effer-
vescence.

Since these experiments were made, I have found a very
curious memoir by Keir, in the Transactions of the Royal
Society of London for the year 1790, entitled, Experiments
and observations on the dissolution of metals in acids, and their
precipitatio?is ; in which several facts of this kind are recorded.

Keir was led to remark the prepared state of iron, when
studying the precipitation of silver by that metal, in which
Bergman had previously found some anomalies. He even
discovered that this singular state may be developed by the
action of nitrous acid. But the remarkable effects arising
from contact with other metals, by which these facts may be
included in the class of electro-chemical phenomena, escaped
his observation. That the contact of one metal should pro-
tect another from the action of a chemical agent, as long as
the contact lasts, does not now surprise us; (it occurs when
nitric acid is poured over a piece of copper placed upon pla-
tina;) but what to me appears extraordinary in the experi-
ments above described is, that the effect can be indefinitely
prolonged after the contact ceases ; and that a permanent elec-
trical state may exist on the surface of a metal, and be there
maintained by its own power, contrary to that which ordi-
narily exists in the same metal, and to that which continues to
exist in it at a very small depth in its interior, even during
the existence of the forced state at the surface.

Slough, Aug. 19, 1833.

XLI. A Beporton the Progress of Photochemistry in the Year
1835, in reference to the Physiology of Plants. By J. C.
Marquart.*

[Continued from vol. xi. p. 166, and concluded.]
Vl/'E have received this year very important additions to the
* * knowledge of the alkaloids. What was formerly de-
scribed as Atropia, Hyoscyamia and Daturia must, according
to the discoveries of Brandes, be expunged. They are not
alkaloids; this discovery was left for Mein, Geiger and Hessef.

* From Weigmann's Archivfur Naturgeschichtc, vol. ii., part iv., p. 139
et seq. Translated by Mr. Wm. Francis.

f Geiger and Liebig's Anna/cn, vol. vii. p. 269.

334 J. C. Marquart's Report of the Progress of Pht/lochemistry

Chemists, it is true, distinguish the alkaloids from the henbane,
the deadly nightshade, and the thorn-apple ; they appear to us
however so nearly related to each other, that their difference
consists in their greater or less degree of purity. One might de-
signate them as the bases from the Solaneae if the genus Sola-
tium did not contain an alkaloid differing from them, and which
is principally distinguished from the above by the circumstance,
that it causes no dilatation of the pupil, which property belongs
to the former in a very high degree. The history of the alkaloids
obtained from the genus Solatium seems to us yet to be rather
in darkness : for the bases from the above-named genera pos-
sessing the property of dilating the pupil, a name should be
chosen, from one of them. They are contained in all parts of
the plants combined with an acid. In their pure state they are
colourless transparent prisms with a silky lustre, void of smell,
not volatile, and melting at S0° Reaum. A characteristic pro-
perty for all three is that they lose their property of crystal-
lizing when in contact with water, and then take the narcotic
smell of the plants. They may however be reduced to a cry-
stalline state by employing the same method as in their first
preparation. They combine with acids forming neutral cry-
stalline salts, and exhibit, especially towards tannin, an ex-
traordinary affinity, as their solutions gelatinize with tincture
of galls. We know their elementary composition from the
base of the Atropa Belladonna ; it consists of Cg4 H23 Ofi
N, ; and the elementary analysis of daturia and hyoscyamia
will shortly show whether our supposition above is sufficiently
confirmed.

Geiger and Hesse* also separated from the seeds of Col -
chicum autumnale an alkaloid in a condition which showed its
nature better. It was formerly considered identical with the
base from the genus Verafrum, from which it however differs
in some degree. Its taste is irritating, but not sharply caustic
like veratria, and it does not cause any sneezing. By neutral-
ization with acids it forms in part crystalline salts.

The aconita of the older chemists must also be struck out,
according to the recent preparations of Hesse f, who found in
the leaves of Aconitum Napcllus a bitter highly poisonous
but not acrid basis, which, in its purest state, forms white
granules or transparent masses with a glassy lustre, which dis-
solves easily in alcohol and aether, but with more difficulty in
water. The salts formed by this base with acids were not
crystalline.

The alkaloid discovered by Lancelot in the leaves of Digi-

* Geiger and Liebig's Annalen, vol. vii. p. 261). f Ibid.

in the Year 1835, in reference to the Physiology of Plants. 335

talis purpurea has also been obtained by Radig *, and recog-
nised as a real alkaloid.

We are yet unacquainted with the origin of the drug known
under the name of disco bark ; it belongs according to chemi-
cal observations certainly to the bark of some Cinchonacea?.
Wincklert prepared the Cusconin which had been dis-
covered in it by Pelletier and Leverkohn. It possesses great
similarity to the known cinchonic bases, melts like quinia, is
not so easily sublimed, and differs in its elementary composi-
tion. Thus cinchonia, quinia, and cusconia appear to be ox-
ides of a radical (C20 H24 N2) which contain 1, 2 or 3 atoms
of oxygen.

O. Henry J examined the leaves and fruit capsules of Cin-
chona micrantha, which contained no cinchona-alkaloid and no
cinchonate of lime ; he found these substances, on the contrary,
in the sap which had flowed from the stem, and in the root of
this tree. We have further received notices from Winckler§
on brucia and solania, from Vasmer and Geiseler || on ve-
ratria and strychnia, from Clement Leef on sanguinaria,
and from Peretti** on pitoyn.

We must take for granted that our readers are acquainted
with the earlier experiments on the chemical history of opium,
or the dried milk sap of the unripe heads of poppies, so that
we need make but a general mention of the two important
papers of Pelletierff and Couerbe Jf. This infinite mine of
interesting substances lately presented Pelletier with two, one
of which showed the same elementary composition as morphia,
and was named by Pelletier, Paramorphia ; to the other he
gave the name of Pseudo-morphia. We can only here speak
of the first, since Pelletier did not always obtain the second
under exactly the same circumstances. Notwithstanding the
similar composition of morphia and paramorphia, the latter
differs from the first by its solubility in sulphuric aether, by
the property of not being coloured blue by salts of iron, and by
its incapability of forming crystalline salts with acids; it pos-
sesses, however, the nature of an alkaloid, and differs in that
respect, as well as by its styptic and metallic taste, and crystal-
line form from narcotina. It belongs to the most violent poisons,
as one grain produced violent rigid spasms and death in a dog.

* Ehrmann, Pharm. Novellen, 1834, part 2.

f Buchn. Repert.y vol. li. p. 171.

j Journ. de Pharm , October 1835.

§ Buchn. Repert.t li. || Archivfiir die Pharmacxe> vol. ii. part 1.

f The American Journ. of Pharm., 1835. April.

•■• Gazetta eclettica di Farmacia, 1835. No. 8.

•ft Geiger and Liebig's Ann. der Pharm., vol. xvi. part I.

\% Journ. de Chim. Med. December 1835.

336 J.C Marquart's Report of the Progress of Phytochemistry

Pelletier further proved that there could be no doubt as to the
existence of the narceia which he had discovered in opium;
that the codeia discovered by Robiquet is not the result of
the reaction of a certain substance in the opium; that from
one and the same quantity of opium, narcotina, morphia, nar-
ceia, meconia, codeia and paramorphia might be obtained.
Of particular interest to physiology is the examination of
opium obtained from heads of poppies cultivated on the grounds
of General Lamarque at Eyris, DepU des Landes. Pelletier
found in it no trace of narcotina ; on the other hand, a much
larger quantity of morphia than in the oriental opium. There
was also, excepting a small quantity of codeia, none of the
other constituent parts cf the oriental opium to be found in it.
We have, however, received notice that some opium grown
in Sicily contained quite as much morphia as the oriental : on
the contrary, Winckler* found in the unripe heads of poppies
cultivated on the Bergstrasse only a small quantity of codeia,
rather plenty of narcotina, and no trace of morphia.

The latest discovery in this part of phytochemistry is the
preparation of pure quassin, the long-suspected base (and
as such received) of the wood of Quassia amara, in which
Winckler f succeeded. He obtained it in the form of small
colourless columns possessing a dull lustre, which were easily
soluble in water and alcohol and insoluble in aether. Their
solutions possess an alkaline action, taste exceedingly bitter,
and are precipitated by tannin.

The following, to which different names have been given,
do not belong to a less distinguished section of vegetable sub-
stances. We consider them as the so-called extractive mat-
ters in their purest state, which often appear crystalline,
dissolve in water and alcohol, at times in aether also, and
whose solutions are neutral. The greatest part of De Can-
dolle's:}: hyperhydrogenous substances, or substances similar
to resins, belong to this place: we find however his designa-
tion very inappropriate.

Lasch extracted salicin §, with which we were previously
acquainted, also from the female catkins and young branches
of several species of willows. Tischhauser || obtained it from
the bark, and Herbergerf from the leaves of willows along
with populin, with however four times as much of the former
as of the latter. Landerer** prepared from young oranges
cultivated in Greece, the bitter-tasting hesperidin, which was

• Buchn. Bepert.y vol. liii. part 3. f Ibid., vol. liv. part 1.

i Physiologie, German Transl. by Roeper, p. 327- [Original edition,
Paris, 1832, vol. i., p. 350.— Edit.] § Archiv fur die Pharm., vol. i.

|| Berliner Jahrbuchcr,xxx\v. 2. % Bnchn. Bwpert.', vol. li. part 1.

•* Ibid., vol. Hi. part 2.

in the Year 1835, in reference to the Physiology of Plants* 337

discovered by Lebreton : its solution is said to act as an acid,
which we doubt. T. Martin* extracted cathartin, which was
discovered in the leaves of senna, also from the leaves of an
American Cassia maiylandica. Those cultivated in Europe
are said not to contain it. The santonin discovered by Kohler
in the calathia? of Artemisia glomerata was more carefully re-
examined by Trommsdorfff. It forms dazzling white com-
pressed six-sided columns, which become yellow in the light
even in confined air; they melt at 180° Reaumur, and are
sublimable in open vessels. It consists according to the ele-
mentary analysis of C5 H6 O, .

Poggiale % has experimented on the salsaparilla root, and
recognised as identical the substances described under the
names of paryglin, and salsaparin and parillin acids, and he
has given a method of preparing salsaparin in a pure state. It
then appears as white small acicular crystals which are de-
composed by concentrated nitric acid and form oxalic acid, and
are coloured dark red, almost violet, by sulphuric acid. Pog-
giale found salsaparin to consist of C8 H15 03. According to
Petersen § it contains one atom more carbon than Poggiale
has stated, has not a nauseous bitter taste, and does not possess
an acid reaction.

This is so far of importance, that the chinova bitter disco-
vered by Winckler in China nova (Buena hexandra?) has, ac-
cording to the experiments of Buchner, jun., || the same com-
position and properties as Poggiale gives to his salsaparin, and
Buchner therefore considers them to be one principle, which
must appear rather strange of substances from plants so dif-
ferent as Smilax and Cinchona, This subject therefore requires
a close examination.

A very interesting recent discovery is that of the phlorrizin %
of De Koninck, which may be obtained in a crystalline state
by boiling the bark of apple trees, and then evaporating. It
is often contained in the fresh bark up to 5 per cent., and ap-
pears to be diffused in the family of the Pomaceae, perhaps
characteristic of them all. It is obtained as whitish needles
with a silky lustre, which contain at the common temperature
7 per cent, of water of crystallization. It melts at 103°, and be-
gins to decompose of itself at 193° with formation of benzoic
acid. It dissolves easily in boiling water and alcohol, with dif-
ficulty in cold water, not at all in aether. Concentrated nitric

* The American Journ. of Pharm., 1835, April,
f Annalen der Pharmacie, vol. xi. part 2.
J Journ. de Pharmacie, 1834, p. 553.

iAnnal. der Pharm. ,vol. xv. part 1. || Buchn. Repert., vol. liii. p. 1.
f [See Lond. and Edinb. Phil. Mag., vol. viii. p. 444.— Edit.]
Third Series, Vol. 11. No. 68. Oct, 1837. 2 X

338 J. C. Marquart's Report of the Progress of PJiytochemistry

acid changes it into oxalic acid, by which circumstance it dif-
fers from populin. It consists according to Petersen * of C4 H5
02, from which the statement of the discoverer, C14 H13 03,
widely differs.

Bonastref obtained from the distilled water of aromatic
pink, a crystalline substance, which according to its physical
properties belongs to this place; it has been named by him
eugenin, but according to Dumas it is a hydrate of the aethereal
oil of pinks with a certain quantity of mixed water.

What was lately described by Roger as digitalin, is no al-
kaloid but belongs to this section, and has been called by
Radig, who submitted the base from Digitalis to a more accu-
rate examination, picrinj.

Fremy§ extracted from the fruit of JEsculus Hippocastanwn,
a substance similar to the saponin of Saponaria, which distin-
guishes itself particularly by the circumstance that when treated
with hydrochloric acid, a peculiar acid, sesculic acid, is ob-
tained from it. We did not mention this under the acids, be-
cause as yet it is uncertain whether it is a product or an educt.

The berberin discovered by the Buchners, father and son||,
in the bark of the roots of Berberis vulgaris, belongs, from its
degree of solubility, to this section, and ranges itself near to
phlorrizin ; it contains however nitrogen, €33 H^ N2 012, by
which it differs from rhabarbarin, to which in other respects it
is nearly allied. Buchner brings it under the section of sub-
acids, a reference not very appropriate. It forms a light yel-
low powder, consisting of fine silky needles, which becomes
red at 100° Reaum., and yellow again when it becomes cold;
it melts at a higher degree of heat. It is insoluble in sulphuric
aether, and petroleum; alkalies and most of the metallic salts
form with it orange-yellow combinations.

The peculiar basis of the colour of Lichens was found by
Gregory^ also in Variolaria amara, and must not be con-
founded with the variolarin mentioned in De Candolle's Phy-
siologie, but is more similar to erythrin. This substance is
easily soluble in alcohol and aether, less so in water, tastes
bitter, loses its bitterness by the action of vapour of ammonia,
and becomes red. The orcin discovered by Robiquet in Va-
riolaria dealbata is volatile at 100°, and sublimes into a cry-
stalline thick enamel-like mass. Its composition according to
Robiquet**isC14H2205.

* Annalen der Pharmacie, vol. xv. part 1.

t Journ. de Pharm. Oct. 1834.

X Pharm. NoveUen, von Ehrmann, 1834, part 2.

§ Ann. de Chim. et de Physique, Jan. 1835.

|| Buchn. Repert., lii. part 1.

f Journ. de Pharm., Juin, 1835. *♦ Ibid. Aout, 1835.

in the Year 1835, in reference to the Physiology of Plants. 339

Of inorganic substances which have been found in plants we
can only mention those remarkable either by their rarity or
quantity; and with regard to the latter, we must notice the often
mentioned paper of Radig on Digitalis, who states that he
has found in the herbaceous part 3*7 per cent, of oxide of
iron. Also the memoir of Struve* on the siliceous contents
of some plants. The author determined only the quantity of
silica in the ashes ; he should have taken into consideration
the proportion of silica to the vegetable substance in order to
render his labours of more physiological importance. Under
this section belongs also a part of the crystalline formations
discovered in plants, to which De Candolle has given the
name of Raphides, and, among others, those found by Nees
von Esenbeck in the root of Mirabilis longiflora, consisting,
according to him, of phosphate of lime and magnesiaf. The
examination of these crystals is always connected with many
difficulties; and we seldom succeed in obtaining the object so
pure as in the case which Fr. Nees von Esenbeck mentions %,
and as in that where the author [Marquart] obtained from
the stem of Aloe arborescens pure raphides in such a quantity
as to be able to submit them to careful analysis, which con-
vinced him that in this case the acid could not be of organic
nature, but phosphoric acid combined with lime and magnesia,
as in the above-mentioned raphides from Mirabilis longiflora.
These data do not exclude in any way whatsoever the state-
ments, that crystals of oxalate of lime may also frequently be
found in the cells of plants. Among others we may just no-
tice the oxalate of lime in the root of Rheum australe, which
I however have never been able to see under the microscope
in a crystalline form, but more in the state of granular ex-
crescences. Not unimportant to the explanation of the oc-
currence of salts of difficult solubility in the interior of plants
may be the old observation of Vauquelin § (almost forgotten)
which he made on occasion of analysing forty-seven varieties
of potato, and according to which phosphate of lime dissolves
in water, when some mucilaginous substance, gelatinous starch
or animal gelatine, for instance, is mixed with it. The state-
ment of Treviranus || that plants which contain raphides when
cut attack the knife and blacken it, may be liable to many ex-
ceptions; and certainly the occurrence of raphides and the
property of blackening the knife, stand in no relation to one
another.

* De Silicia in plantis nonnullis. Dissertatio inaugural. Auctore Struve.
Benin, 1835. [See also the present volume, p. 13, 17. — Edit.]
f Physiologie der Pflanzen, vol. i. p. 47.

X Buchn. Repert., vol. xlii. § Mem. du Mus. d'His. Nat.y vol. iii. p. 241.
II Flora, 1835. No. 26. p. 211.

2X2

[ 340 ]

XLII. On the Bromo-cyanide and Chloro-cyanide of Potas-
sium and Mercury. By R. H. Brett, Esq.*
HPHE iodo-cyanide of potassium and mercury has been de-
A scribed by Liebigf, according to whom, the mercury in
the cyanide is combined with twice as much cyanogen as would
be necessary to convert the potassium of the iodide into cy*
anide of potassium, from which statement it would appear
that the double salt is compounded of an atom of iodide of
potassium, and an atom of bicyanide of mercury, its symbolic
representation would therefore be K I + Hg 2 Cy. The salt
in question is deposited in crystals, when saturated solutions
of its component salts are mixed together, or still better when
an alcoholic solution of iodide of potassium is added to a sa-
turated solution of bicyanide of mercury in water. This salt
when collected on bibulous paper and dried possesses a re-
markable brilliancy, assuming the appearance of plates not
unlike cholesterine; it is heavy, speedily sinking in water, in
which, as well as in alcohol, it readily undergoes solution, espe-
cially with the assistance of heat. The acids even when di-
luted decompose it, causing a deposition of biniodide of mer-
cury and evolution of hydro-cyanic acid. The salts about to
be described, also compounded of two haloid salts, and which
I shall call the bromo-cyanide and chloro-cyanide of potas-
sium and mercury, may be obtained in the following manner.

The Bromo-cyanide of Potassium and Mercury. — If to a so-
lution of the bicyanide of mercury in water, an aqueous solu-
tion of bromide of potassium be added, and the fluid set aside,
after some time crystalline plates of much brilliancy, and very
like cholesterine in appearance, begin to pervade the fluid ; if
cold and saturated solutions of the salts be employed, the cry-
stalline deposit takes place at once. The readiest mode per-
haps of obtaining this double salt is to mix moderately concen-
trated solutions of the two components, evaporating the result-
ing fluid to a small bulk, and then transferring the fluid to a
convenient glass vessel, to plunge the whole into cold water, by
which means the largest amount of double salt is obtained ;
this should be thrown on a filter and washed with a very small
quantity of cold water, then pressed between folds of bibulous
paper until all moisture is removed. By somewhat slow cry-
stallization from an aqueous solution, this salt may be ob-
tained in delicate acicular crystals; these under a microscope
appear to be flattened quadrangular prisms.

The salt in question is soluble both in hot and cold water,
also in alcohol, especially when hot.

* Communicated by the Author.

f The iodo-cyanide of potassium and mercury was described by Dr.
Apjohn in 1831, Phil. Mag. and Annals, N.S. vol. ix. p. 401.— Edit.

Mr. Brett on Bromo-cyanide of Potassium and Mercury. 841

One part of the salt requires about 13*34 parts of water, at
the temperature of 65° Fahr., for solution. It is however so-
luble in less than its own weight of boiling water.

Diluted sulphuric acid does not decompose this salt even
when heat is applied, it however undergoes solution.

Concentrated sulphuric acid, sp. gr. 1*845, does not decom-
pose it even upon the application of heat, it suffers solution
in the hot fluid, and is not thrown down again by the addition
of water.

Neither diluted nor concentrated nitric acid appears to de-
compose it, although it undergoes solution. Hot nitric acid,
sp. gr. 1*48, dissolves it without apparent decomposition, water
does not throw it down from such solution.

Hydro-chloric acid, sp. gr. 1*16, dissolves it even in the
cold, the hot fluid does not appear to decompose it.

Sulphuretted hydrogen readily decomposes it with the evo-
lution of hydro-cyanic acid, it is also decomposed by the
hydro-sulphurets. The caustic alkalies, potass and ammonia,
do not decompose it. By the agency of heat it fuses and
blackens, suffering decomposition.

In order to determine its atomic constitution, 15 grs. of the
salt, previously well dried over a sand-bath, were dissolved in
water, to this solution an excess of a concentrated acid solu-
tion of proto-chloride of tin was added, and the whole boiled
for a few minutes, during which time much hydro-cyanic acid
was evolved ; the vessel was then corked and kept at rest for
some hours, the clear supernatant fluid was then tested with
some more of the solution of the salt of tin ; no precipitate being
produced, the whole was carefully removed; the finely divided
metallic mercury at the bottom of the vessel was then boiled
for a short time only with pure hydro-chloric acid, after some
time the clear supernatant fluid was again removed, and after
boiling once more with diluted hydro-chloric acid, and re-
moving the greater part of the clear supernatant fluid, the
remainder, together with the metallic mercury, was transferred
to a small glass capsule, and allowed to dry at the prevailing
atmospheric temperature ; the mercury which had run into
globules was then weighed.

Fifteen grains of the salt were again taken, dissolved in
water, and the solution treated with a slight excess of hydro-
sulphuret of ammonia, the whole was then boiled for a few
minutes, and when cold, filtered ; the filter was well washed
with distilled water, and the washing being added to the fil-
tered fluid, the whole was evaporated in a porcelain capsule
to a very small bulk, the fluid thus concentrated was transferred
to a platinum crucible, to which was added the washings of

342 Mr. R. H. Brett on the Bromo-cyanide and

the capsule : the whole was then slowly evaporated over a
sand-bath to dryness; the residue was then exposed to a dull
red heat for some time and weighed as bromide of potassium.

The following were the results of two experiments.

Exp. 1. Mercury 7*5 = bicyanide of mercury 9*43

bromide of potassium 4*50.

13-93.
Exp. 2. Mercury 7*5 = bicyanide of mercury 9*43
bromide of potassium 4*70

14-13.
Calculated proportions, assuming the double salt to be com-
pounded of an atom of each of its constituents.
Bicyanide of mercury ... 10*241
Bromide of potassium... 4*758

14-999.
Now as the quantity of mercury contained in the calculated
proportion of bicyanide is about 8*144, the difference between
it and the quantity obtained by actual experiment is only
0*644, for 8*144 — 7*5 = 0*644. In the 2nd experiment the
quantity of bromide of potassium obtained very closely ap-
proaches to the calculated proportion — as 4*70 to 4*758. It
may, I think, therefore be fairly deduced that the double salt
is composed of an atom of each of its constituents, and may be
represented thus : KBr-f Hg 2 Cy, or
Bicyanide of mercury 1 atom = 254
Bromide of potassium 1 atom = 118

372 atomic weight of

In 100 parts 68*279 the salt.

31*721

100*000.

The Chloro-cyanide of Potassium and Mercury differs
scarcely at all in appearance from xhe salt last described, and
may be obtained precisely in the same way, substituting the
chloride for the bromide of potassium. It is however more
soluble in water than the bromo-cyanide, one part of the
salt requiring only 6*75 parts of water at 65° for solution.
The mineral acids and the alkalies do not decompose it. It
is however readily decomposed by sulphuretted hydrogen and
the hydro-sulphurets.

In order to ascertain its atomic constitution it was analysed
in the same manner as the last salt.

Chloro-cyanide of Potassium and Mercury, 343

15 grs. of the salt yielded by the 1st experiment,
Mercury 8*6 grs. = 10*81 of bicyanide of mercury.
3* of chloride of potassium.

13-81
2nd Experiment.

Mercury 8*6 = 10*81 bicyanide of mercury.
3*40 chloride of potassium.

14*21
By calculation, assuming the salt to be composed of an
atom of each of its constituents.

1 1 *29 1 bicyanide of mercury.
3*708 chloride of potassium.

14*999

The numbers obtained by experiment approach sufficiently
near to those which result from calculation to warrant the
conclusion, that the double salt is composed of an atom of each
of its constituents, and may be thus represented : K CI
+ Hg 2 Cy, or,

Bicyanide of mercury 1 atom = 254

Chloride of potassium 1 atom = 83*42

337*42 atomic weight

In 100 parts 75*277 of salt.

24*723

100*000.

I may observe that in these experiments and calculations,
the atomic weight of chlorine has been taken as 35*42, that
being the number somewhat recently announced by Turner,
and agreeing nearly with that deduced from the experiments
of Berzelius.

July 3, 1837. R. H. Brett.

P.S. Since sending the preceding analyses for insertion in
the Philosophical Magazine, I have been informed by Mr. R.
Phillips, that the bromo-cyanide of potassium and mercury
has been described, and an analysis given by M. Caillot in
the Journal de Pharmacies tome xviii. p. 351. This salt is
called by Caillot the cyan o-hydrargy rate of the bromide of
potassium, believing as he does that the bicyanide of mercury
plays the part of the electro-negative or acid element, whilst
the bromide of potassium takes upon itself the electro-positive,
or base function : his mode of obtaining the salt is much the
same as that which I have described. M. Caillot considers

344 Mr. Beke on the Complexion of the Ancient Egyptians.

that it contains 8*74 per cent, of water of crystallization. Now
the atomic weight of the salt according to my experiments is
372, and if the above per centage of water of crystallization
be taken as correct, it will be found that 372 parts of the
anhydrous salt will combine with 35*62 parts of water, which
is very nearly equal to 4 atoms ; this agrees with the state-
ment of M. Caillot, who considers the quantity of water in his
salt as equal to 4- atoms. The proportions of the constituent
salts in 100 parts as given by Caillot, is very nearly the same
as that given in my analysis : according to him the propor-
tions are as follows : Bicyanide of mercury 68*49 ; bromide
of potassium 31*51. M. Caillot says that diluted nitric acid
when mixed with the salt decomposes it, forming nitrate of
potass and bi-bromide of mercury, and disengaging hydro-
cyanic acid ; and certainly, reasoning from the known action of
many of the acids upon the iodo-cyanide of potassium and mer-
cury, we might a priori have expected this. In my own experi-
ments, however, I did not find it to be the case, for when the
salt was carefully prepared, so that no uncombined bi-cyanide
of mercury was present, the cold, and even concentrated
mineral acids did not disengage any hydrocyanic acid, neither
did the same acids when hot; a prolonged digestion with or
without heat would in all probability effect a decomposition,
and it is more than likely that this was done in M. Caillot's
investigations.

I cannot find that the chloro-cyanide of potassium and mer-
cury has been described. Being at present engaged in the
investigation of the salts formed by the combination of bi-
cyanide of mercury with certain haloid salts of the alkaline
metals, as well as with the organic alkalies and the chloride
and bromide of ammonium, I hope to make them the subject
of a future communication.

R. H. B.

XL 1 1 1. On the Complexion of the Ancient Egyptians. By
Charles T. Beke, Esq., F.S.A*

HPHE main difficulty which has had to be contended with,
•*■ in the consideration hitherto given to the subject of the
colour of the ancient Egyptians, is this; — that, whilst the
only conclusion which we are warranted in drawing from the
descriptions given of that people by the earliest writers of
Greece, is, that they were in outward appearance almost si-

* From the Transactions of the Royal Society of Literature, vol. iii.
Part I. ; read before the Society on March 24th, 1836.

Mr. Beke on the Complexion of the Ancient Egyptians. 345

milar to the African negroes of the present day; — our know-
ledge, derived from all other sources of information, is, or at
least seems to be, diametrically opposed to such a conclusion.

The chief of these conflicting testimonies may be thus sum-
marily stated. On the one side we have ; — first, a passage of
the poet iEschylus, in which the crew of a vessel, seen at a
distance, are said to be known for Egyptians by their black
colour: —

Yviotat ~KtvKU<j tx, nvix'Koi^uruv ihilu. — Suppl. 727, 8.

and, secondly, the testimony of Herodotus, who personally
visited Egypt, and who, consequently, must have known full
well the real colour of its inhabitants. It is true, that the
historian's opinion upon the subject is to be gathered rather
by inference, than from any express description given by him
of the complexion of the Egyptians; but this circumstance
only renders the inference the stronger, as we are thereby led
to believe that their colour was a matter of sufficient notoriety
among the Greeks, to make the express mention of it unne-
cessary. Of the two passages of this writer which are to be
adduced, the one is that wherein he explains the tradition
that the oracle at Dodona originated in a black dove which
had flown from Thebes in Egypt, by supposing that the oracle
was instituted by a Thebaean female; and that the circum-
stance of the bird being black, showed that the woman was of
Egyptian origin : ^Kolivolv $j Asyovrsj shai ryv TreAsia&x, cnj-
p.otlvov<Ti on AlyvnTtYi ^ yvvy yv (Euterpe, 57.) the other pass-
age is in the account given by him of the Colchians (Euterpe,
104.), in which the historian asserts his belief in their Egyp-
tian descent, because they were of black complexion and woolly-
Jieaded, xai oti [xsXay^goss e\<ri xcti ou^orpix^S-

As opposed to the conclusion which is to be arrived at from
the consideration of the foregoing authorities, we have, on the
other hand ; — first, the testimony of the Hebrew Scriptures,
from which testimony (although indeed it is of a negative cha-
racter only) it is unquestionably to be inferred, that the people
in whose country Joseph became naturalized, so that his
brethren believed him to be a native of it (comp. Gen. xlii.
23. 30. 33.); — with whom alliances were permitted by the
Israelitish lawgiver (Deut. xxiii. 7, 8.); — one of which people
was, in fact, the mother of the heads of two of the tribes of
Israel (Gen. xli. 50 — 52.), and another of whom was, at a
later period, the wife of King Solomon (1 Kings, iii. 1.); —
could not possibly have been of a much darker complexion
than the Israelites themselves. Had such been the case, we
should indubitably have met with some mention of the fact,

Third Series. Vol. 1 1. No. 68. Oct. 1837. 2 Y

346 Mr. Beke on the Complexion of the Ancient Egyptians,

or at least with some reference or allusion to it, similar to that
which is made by the prophet Jeremiah (xiii. 23.) respecting
the colour of the Cushites.

Secondly: in times when the communication between Egypt
and Europe was common and uninterrupted, and when so re-
markable a peculiarity, had it existed, could not have failed
to be noticed, we have the like negative evidence of the later
writers of Greece and Rome. It is true, that there is a de-
scription given by Lucian, in one of his Dialogues, (/Navigium,
seu Vota,') of a young sailor on board an Egyptian vessel,
who, besides- being black, is represented as having pouting
lips and spindle-shanks ; — qvto$ 8e 7rpb$ tco ^sKuy^poui shut,
xcc) 7rp6^r.iXo^ eo-Ti, xa» Xsktos ayotv toiv (rxeXoh: but, from the
consideration of the context, it is impossible to regard this
description as applicable to the Egyptians generally: on the
contrary, it would seem rather that the individual in question
ought to be regarded as having differed in appearance even
from the rest of the crew of the vessel, having been perhaps
a negro or Nubian slave : besides which, it is evident that the
whole description is so caricatured, that much of its value as
an authority is lost*

Thirdly: in the paintings which have been discovered in
the temples and tombs of Upper Egypt, the natives of the
country are usually represented as being of a chocolate or red
copper colour, which we may reasonably infer to have been
their actual complexion at the period when those paintings
were made. The human faces, too, painted upon the mummy-
cases, which likewise may be assumed to be representatives,
although not likenesses, of the individuals whose bodies are
contained in those cases, are of a similar coppery hue.

Fourthly: the naturalists who have investigated the physical
structure of the skulls of the embalmed bodies, have deter-
mined, that they possess none of the decided characters of the
negro; and that, indeed, they differ but little in formation
from the European races of mankind*. The hair, too, upon
the heads of many of these bodies, is found to be totally unlike
the woolly hair of the negroes; it being, in fact, of a soft and
smooth texture, like that of Europeans. From the bodies
themselves no opinion is to be formed of their natural colour,
owing to the changes which the process of embalming has
necessarily caused in them : neither is any certain conclusion
to be deduced from the colour of their hair, which is not un-
frequently brown ; since it is possible that that colour may not
be natural, but may have been induced by the same process.

[* See Phil. Mag. First Series, vol. Ixvi. p. 71 ; and Phil. Mag. and
Annals, N.S., vol. v. p. 5J), 0*4.— Edit.]

Mr. Beke on the Complexion of the Ancient Egyptians, 347

Lastly: we know full well, that in the present day the com-
plexion of the natives of Egypt is far from being black ; and
that, in reality, they possess the general physical characters
of an European or Asiatic, rather than of an African race.

What, then, is the conclusion to be come to under this con-
flicting evidence? It seems utterly impossible to reject alto-
gether the testimony of iEschylus and Herodotus, and espe-
cially of the latter, by which the fact is established, that, at
about 500 years before the commencement of the Christian
aera, the complexion of the natives of Egypt, if not actually
black, was at all events of so dark a shade, that such an epithet
might not improperly be applied to it among the fairer inha-
bitants of Greece: and if we admit this fact, there appear to
exist no means of reconciling it with the other evidences which
have been enumerated, except by the hypothesis which is ad-
vocated in my 'Origines Biblicce*? namely, that the natives of
ancient Egypt were derived from two distinct original stocks;
the one, and the earliest possessors of the country, being of
Ethiopian descent, who entered Egypt from the south ; and
the other being the people who are mentioned in the Hebrew
Scriptures under the name of DH¥p (Mitzrim), or Mitzrites,

who, in all the translations of those Scriptures, from the Sep-
tuagint downwards, are incorrectly called Egyptians; and
their country, Mitzraim, is, in like manner, improperly de-
signated Egypt; and whose original country was not any por-
tion of Egypt itself, but was situate wholly to the eastward of
the isthmus of Suez.

The former of these two peoples was, as may well be con-
ceived, of a race which came from the south, of a dark colour,
approaching to, if not actually, black; and it is to this people
that are applicable not only the descriptions of iEschylus and
Herodotus, but also (see { Orig. BibL' p. 295, note) the allu-
sion of the prophet Jeremiah ; — the Cushites, or Ethiopians,
and the primitive Egyptians being in fact identical.

The latter people, the Mitzrites, being sprung from an
Arabian and northern stock, would not have been of much,
if any, darker complexion than the Israelites themselves; and
hence we can satisfactorily account for the absence in the
Hebrew Scriptures of all reference or allusion to their colour.

A remarkable exemplification of the distinction which thus
existed between the Egyptians and the Mitzrites, is afforded
by the comparison of a notice of iElian concerning the former
people, with a statement contained in the Hebrew Scriptures
respecting the latter. The Roman writer informs us, that

* * Origines Biblicce, or Researches in Primeval History,' vol. i. London,
1834.

2Y2

34*8 M r . Beke on the Complexion of the Ancient Egyptians,

the Egyptians used to boast that their women were not con-
fined to their beds by childbirth, but could immediately after
their delivery resume their domestic avocations: — £1 %l
AlywTrriwv ocl yovciixzg fxsycc <Ppwov<riv, oti xaxeivou ty)v a'SIva ot7roAu-
(roKroti, xxi e£uv<x<rToi<J(xi, tcov epyouv s^ovtoii rwv xoltol tyjv olxiav.
' De Nat. Anlmal.\ lib. vii. c. 13 *. On the other hand, we
learn from the Scriptural history, that among the people over
whom the oppressor of the Israelites reigned, childbirth was
far from being so easy : — " because the Hebrew women are
not as the Mitzritish women, for they are lively, and are de-
livered ere the midwives come in unto them," (Exod. i. 19.)
is the excuse of the midwives who were commanded by Pha-
raoh to destroy the new-born male infants of the Israelitish
mothers.

It will be right here at once to anticipate an objection,
which might be made in accordance with the opinion enter-
tained by J. D. Michaelis, (see his ' Supple m. ad Lex. Hebr*
in voc. rTn) that the word in the text, DVn, should be pointed

ni*n, and translated midwives; whence the passage would

have to be read, " because the Hebrew women are not as the
Mitzritish women, for they are themselves midwives" &c. ; or,
as the Vulgate has it, " ipsa? enim obstetricandi habent scien-
tiam;" in which sense the expression in question is under-
stood in many other ancient versions. To this objection a
sufficient answer is given by Rosenmiiller {Scholia in loc);
namely, that as throughout the whole relation the Mitzritish
midwives are called Jli^TTfJ, ai)d there does not appear any

reason why the historian should employ two different words
to express one and the same idea, the meaning attached by
Aben-Ezra to the word in question, (and adopted also in our
authorized version,) namely, " lively," " robust," is to be pre-
ferred. Jarchi says, that the Rabbis understood the expression
to mean, " because they are like the beasts of the field, which

* My attention was called to this subject, in its present form, by the
perusal of the article 'iEgvpUis* in • Lempriere's Classical Dictionary,' (by
Barker, second edition, London, 1832,) in which, §8, 'On the Com-
plexion and Physical Structure of the Egyptians,' pp. 43— 46, the va-
rious authorities which are thus far cited are collected and commented
upon; the principal matter of the remarks being apparently taken from
Dr. Prichard's • Physical History of Mankind;' — a work, to which I have
not at present the opportunity of referring. As might be supposed, how-
ever, no satisfactory conclusion could be arrived at by the author, whilst
the notion of the identity of Miizraim and Egypt was retained. My own
conclusions, upon all material points connected with the subject, had been
expressed, though not in this developed form, in my ' Origines Biblicas*
long previously to my perusal of the article in Lempriere. — 20th Julyt
1835.

Mr. Beke on the Complexion of the Ancient Egyptians. 349

bring forth without assistance;" which comes to the same
thing.

But admitting for a moment that Michaelis's construction
be the correct one, it is still manifest that among the Hebrew
women childbirth is stated to have been so easy, that they
could dispense with the aid of the midwives; and that, in fact,
they were able to deliver themselves. This assertion may, or
may not, have been true: from Exod. i. 17. it would seem
rather that it was not so, and that, on the contrary, the Mitz-
ritish midwives did actually assist the Hebrew mothers ; but
that they " feared God, and did not as the king of Mitzraim
commanded them, but saved the men-children alive." The
truth, or untruth, of their assertion is however entirely imma-
terial to the consideration of the present question, which re-
lates to the Mitzritish, and not to the Hebrew women. Now,
as the midwives expressly told Pharaoh that the Hebrew wo-
men could dispense with their assistance, and that in this re-
spect " they were not as the Mitzritish women," it was equi-
valent to the assertion, that the latter, on their part, did re-
quire such assistance : and as this excuse was allowed to pass
current with the tyrant, (which would scarcely have been the
case, had it been untrue in this respect also,) it affords the
strongest evidence of the physical character of the Mitzritish
women in this particular; and hence the distinction is suffi-
ciently established between them and the women of Egypt, as
described by iElian.

For various other arguments in confirmation of the distinc-
tion existing between the land of Mitzraim of the Hebrew
Scriptures, and the Egypt of profane history, it is sufficient
for me to refer to the work already alluded to.

The separation and distinction between the Egyptian and
Mitzritish nations continued (there is reason to consider) until
about the time of the Israel itish king, Solomon. At that pe-
riod, wars between them ensued, in which the Mitzrites were at
first the conquerors; but after a time, the Egyptians regained
their independence, and in the end acquired the supremacy.
Of these occurrences we have manifest traces in the corrupted
and distorted fragments of Egyptian history which have come
down to our time, although the period when they took place is
thrown back to a much earlier date. The country of Mitzraim
being thus subjected to the dominion of Egypt, and being
further devastated by continual aggressions on the part of the
Assyrians and Babylonians, whilst, from its peculiar locality,
it was obnoxious to I he desolating action of physical causes also,
became gradually deprived of its political existence, and at
length was merged and altogether lost in its more prosperous

350 Mr. Beke on the Complexion of the Ancient Egyptians.

neighbour, Egypt. That Herodotus and other writers should
not in any manner allude to the separate existence of Mitzraim,
is, in reality, not more remarkable than that they should omit
all mention of either of the neighbouring kingdoms of Judah
and Israel ; whilst the corrections which have been made in
the early history of most nations, when they have been sub-
jected to the test of extensive research and severe criticism,
plainly show how little dependence is to be placed upon the
unsupported traditions and fables of native writers, who are
but too often found to be willing to enhance the antiquity and
glory of their country at the total sacrifice of the truth.

The natural result of the union between the Egyptians and
Mitzrites would have been an amalgamation, to a certain ex-
tent, between the two races, and (as we see continually in-
stanced in the present day) the offspring of connexions be-
tween them would, in complexion and other physical charac-
ters, have been intermediate between the two parent stocks.
It may be added, that besides the partial change of colour
which would hence have ensued, many important alterations
in the customs of the Egyptians must necessarily have been
consequent upon their original subjection by the Mitzrites.
Among these is particularly to be mentioned the introduction
of the practice of embalming the dead ; a custom, which we
are expressly told was not of Ethiopian origin, (see Herod.
Thalia 24-. Diod. ii. 14. Strabo xviii. 23.) but which we know
to have been common among the Mitzrites as early as the
time of the patriarch Joseph. (See Gen, 1. 3. 26. 30.) A
corollary upon this will be, that no Egyptian mummies can be
of a date anterior to the Mitzritish invasion of Egypt, (circa
1000 b. c.) : many, nay, most, of those which have, up to
the present time, been brought to Europe, are manifestly of
the period of the Ptolemies only.

But, in addition to the cause of variation in the colour of
the Egyptians which has already been mentioned, another
cause, and one of which the results would have been yet more
perceptible, had, about two centuries previously to the time
of Herodotus, begun to operate: this was the introduction of
Greek settlers by Psammeticus, and the encouragement which
was given to the immigration of that people during three
whole centuries previous to the accession of a Greek dynasty
to the throne. Subsequently to this latter event, and whilst,
during three centuries longer, the Ptolemies continued sove-
reigns of Egypt, the inducement to Greek settlers became still
greater; and thus, during the long period of six centuries
next preceding the commencement of the Christian a?ra, con-
tinual additions of European blood would have been made to

Mr. Beke on the Complexion of the Ancient Egyptians. 351

that of the already mixed breed of the Egyptians and Milz-
rites. Hence the complexions of the inhabitants of Egypt
must necessarily have become fairer and fairer in each suc-
cessive generation ; so that, at the time when the Romans ac-
quired the supremacy of that country, its natives, or at all
events those of Lower Egypt, would have been little, if at all,
darker in colour than the inhabitants of the neighbouring
countries of the Levant. I will say nothing of the immense
number of Jewish emigrants in Egypt; although, not impro-
bably, they likewise would have aided in bringing about this
result.

Whilst however these changes were gradually taking place,
it is evident that shades of colour of every degree, from the
darkest up to the very fairest, would have existed at one and
the same time among the inhabitants of Egypt, in the same ,
manner as, in the present day, we find to be the case in places
where the population is compounded of European whites and
African blacks ; and these diversities must, to a certain extent
at least, have continued to exist in the time of the Ptolemies, and
even of the Caesars ; — and this, doubtless, to a greater degree
in the southern than in the northern portions of the country.
Hence it may not be unreasonable to imagine, that cases would
sometimes arise, in which it might be considered advisable,
in documents of a legal nature, to state, not merely the names,
descriptions, and ages of the parties to them, (in like manner
as is customary in such documents now-a-days,) but also their
complexions. That the complexions of the parties to legal
documents were sometimes described, is clear, from the Greek
papyri translated by Dr. Young ('Discoveries in Hierogly-
phical Literature,' London, 1823, pp. 66. 69.); and without
attaching any undue importance to this circumstance, »I think
it is at least deserving of consideration in the light above sug-
gested.

It is however most natural that the lower classes would have
been those whose blood derived the smallest proportion from
an exotic source, and who, consequently, would longest have
retained the physical characters of the primitive Ethiopian
stock: hence it is not impossible, that the young Egyptian
sailor, described by Lucian, may have been an individual of
the lowest class [of the Egyptians] ; although, as before stated,
it is more probable that he was a negro or Nubian slave.

In thus attributing the origin of the primitive Egyptians to
a black African stock, I must however be distinctly under-
stood as opposing the notion, that the type of that stock is to
be sought for in the negro of the present day. On the con-
trary, 1 conceive the negroes of Africa to be the descendants,

352 Mr. Beke on the Complexion of the Ancient Egyptians.

in an extremely low state of degradation, of the primitive
people, who first entered that continent by the way of Ethiopia,
and who were possessed of a much higher degree of cultiva-
tion than the Egyptians themselves; for it is manifest, that
this latter people, instead of advancing, were, until the period
of the arrival of the Greeks, gradually descending the scale
of civilization, and that the state of manners described by
Herodotus and other writers, (like that which we observe in
the Chinese, among whom imitation is almost all that is left
in the place of the intelligence possessed by their predecessors,)
was the natural result of that degeneracy, which, when un-
checked, is inevitable to human nature.

I am aware, that in this hypothesis of the original separate
existence of Egypt and Mitzraim, I am directly opposed to
the results which are considered to have been arrived at, upon
indisputable premises, by the many learned persons who have
devoted themselves to the study of Egyptian antiquities.
With the highest opinion of the value and importance of the
materials collected by them, which cannot fail to be of the
greatest service to future investigators of this interesting sub-
ject, I cannot but feel convinced that they have been engaged
in the propping-up of a system of Egyptian history, which,
being founded upon altogether erroneous principles, must
ultimately fall to the ground and be entirely abandoned.

In the three papers of mine which had the honour of being
read before the Royal Society of Literature, on the 15th of
January, 19th February, and 11th June, 1834, (as well as in
my * Origines BiblicceJ) I have expressed my conviction that
the writings attributed to Manetho are not authentic. This
conviction is only strengthened, the more I have occasion to
investigate the subject of ancient Egyptian history ; a proper
insight into which will, I feel, never be acquired until those
writings are deprived of authority, and of that appearance of
truth which they have derived from the coincidences said to
have been found between them and the results of the system
of hieroglyphical interpretation discovered by Dr. Young, and
adopted by M. Champollion le jeune.

That in the time of Josephus, these writings were, among the
Egyptians, or rather among the Greeks and Jews, who com-
posed at that period the most important portion of the inhabit-
ants of Egypt, (see 'Joseph. cont.Apion'Wh. ii. § 3.) believed
to be the composition of such an individual as the Sebennite
priest, can in no wise be taken as conclusive evidence of their
authenticity. On the contrary, when we call to mind the
distracted state in which Egypt had existed during so many
centuries preceding that time, and the changes which had

Prof. Dove's Outlines of a general Theory of the Winds, 353

taken place in the government, the manners, and even in the
lineage of its inhabitants, we can have no difficulty in con-
ceiving that much of the real history of the country was for-
gotten and lost, and that in its place, the traditions of the
Jewish settlers (nay, any fables that they may have invented,
of which an example is to be seen in the story of the composi-
tion of the Septuagint version,) may have met with a ready
reception ; and hence, that the whole system of Egyptian hi-
story should have been remodelled, so as to tally with those
traditions. The want of agreement between the history thus
formed, with the particulars of the ancient history of Egypt
afforded by Herodotus and Eratosthenes, and even by Dio-
dorus, (though this last writer, from his much later date, had
acquired a mixture of the false and the true,) afford the
strongest proof of the little reliance which ought to be placed
upon the former ; and this independently of the conclusions
arrived at from other sources, which are directly opposed to
the statements bearing the name of Manetho.

That coincidences are said to exist between these writings
of Manetho and the results come to by M. Champollion and
the disciples of his school, is, I fear, only so much the more
in disfavour of the phonetic system of interpretation ; and it
may perhaps give validity to the opinion, that that system has
not merely been stationary, but has actually retrograded, since
the death of its illustrious founder; and that, in order to cul-
tivate it with the prospect of ultimate success, it will be neces-
sary to go back to the point at which it was left when science
sustained so severe a loss through his untimely death, and from
that point to pursue future investigations of the subject, upon
the same philosophical and solid principles on which his
splendid discovery and its subsequent development were
based.

January 4, 1836. CHARLES T. Beke.

XLIV. On the Influence of the Rotation of the Earth on the
Currents of its Atmosphere; being Outlines of a general Theory
of the Winds. By Prof H. W. Dove of Berlin.

[Continued from p. 239, and concluded.] *

WILL now pass from these direct and indirect observa-
-*■ tions to the following stricter proofs, calculated from the
mean motions of meteorological instruments. The calcula-
tion of thermal and barometrical wind-means shows that the
wind-compass (windrose) possesses two poles of pressure and of
heat, i. e. that there are two points nearly opposite to one an-

Third Scries. Vol. 11. No. 68. Oct. 1837. 2 Z

354 Prof. Dove's Outlines of a general Tlieory of the Winch,

other in it, at one of which it is coldest, and at which the ba-
rometer stands highest ; at the other warmest, and at which the
barometer stands lowest. The barometric and thermal wind-
means decrease uninterruptedly from the maximum of the pres-
sure to its minimum, as also from the maximum of heat to its
minimum. The first point lies near to NE., the other near to
SW. If we now proceed from SW. through W. to NE.,
the mean conditions of the thermometer decrease, while the
mean conditions of the barometer increase; if we go further
from NE. through E. to SW., the mean conditions of the
thermometer increase, while those of the barometer decrease.

That which shows itself in the thermal and barometric wind-
means must also appear in the transitions of the same into one
another, i. e. in the mean thermal and barometric variations,
and indeed as well on the supposition of a changeable velocity
of rotation as of one which always remains the same (Poggen-
dorff's Annalen, vol. xxxi. p. 473). Since however the ela-
sticity of the aqueous vapour, with respect to its distribution in
the wind-compass, is closely related to the thermal, and the
pressure of the dry air to the barometrical, wind-compass ;
it follows, that the changes of the pressure of dry air and of
the barometer are exactly in inverse proportion to the changes
of the temperature of the air and of the elasticity of the aqueous
vapour contained in it. If we now suppose as the necessary
consequence of the former theoretical observations, that the
NW. acts the same part in the southern hemisphere as the
SW. in the northern, that a SE. there represents a NE.
here, we shall have the following result :

A. Mean Variations of the Meteorological Instruments.

Northern Hemisphere. Southern Hemisphere.

1. The barometer falls by 1. The barometer falls with
E., SE. and south winds, E., NE. and north winds,
passes with SW. from falling passes with NW. from falling
into rising, rises with W., into rising, rises with W.,
NW. and north winds, and SW. and south winds, and
passes with NE. from rising passes with SE. from rising
into falling. into falling.

2. The thermometer rises 2. The thermometer rises
with E., SE. and south winds, with E., NE. and north winds,
passes with SW. from rising passes with NW. from rising
into falling, falls with W., into falling, falls with W.,
NW. and north winds, and SW. and south winds, and
passes with NE. from falling passes with SE. from falling
into rising. into rising.

Prof. Dove's Outlines of a general Theory of the Winds. 355

3. The elasticity of the va- 3. The elasticity of the va-
pour increases with E., SE. pour increases with E., NE.
and south winds, its increase and north winds, its increase
changes with SW. into de- changes with NW. into de-
crease, it decreases with W., crease, it decreases with W.,
NW, and north winds, and SW. and south winds, and
with NE. its decrease changes with SE. its decrease changes
into increase. into increase.

4. The pressure of the dry 4. The pressure of the dry
air decreases with E., SE. air decreases with E., NE.
and south winds, its decrease and north winds, its decrease
changes with SW. into in- changes with NW. into in-
crease, it increases with W., crease, it increases with W.,
NW. and north winds, and SW. and south winds, and
with NE. the increase changes with SE. its increase changes
into decrease. into decrease.

What both hemispheres possess in common consists in this,
that the variations of the meteorological instruments are the
same for east winds in the northern hemisphere as for east
winds in the southern hemisphere. The same is the case with
the west winds. The difference of both hemispheres is only
quantitative with NW. NE. SW. and SE. winds; qualita-
tive, on the contrary, with north and south winds ; i, e. the
variations of the meteorological instruments are on an average
in the northern hemisphere greatest with NE. and SW. winds,
smallest (by compensation of the opposite motions) with NW.
and SE. winds ; in the southern hemisphere smallest (by com-
pensation of the opposite motions) with NW. and SE. winds;
greatest on the contrary with NE. and SW. winds. The
variations with north winds in the northern hemisphere are
however, according to the sign, different from the variations
with north winds in the southern hemisphere under equal
climatic influences, but, according to the magnitude, are the
same in both. If therefore an instrument in the northern
hemisphere rises with N., it falls with N. in the southern, and
vice versa. This applies also to the south winds.

The proof of the positions above-stated for the northern
hemisphere are scattered here and there in separate memoirs ;
I will here bring them again together in order to have a bet-
ter general view of them. The confirmation or refutation of
the positions given for the southern hemisphere must be set
aside until made known by journals of observation.

( + ) signifies rising, (— ) signifies falling.

1. The barometer falls with E., SE. and south winds, passes

2Z2

356 Prof. Dove's Outlines of a general Theory of the Winds.

with SW. from falling into rising, rises with W., NW. and
north winds, and passes with NE. from rising into falling.

Paris.

Danzig.

London.

5 Years.

10 Years.

1 5 Years.

s Years.

SW.

+ 0mm-1200

— 0mm-2079

-0"'-088

— 0"-023

wsw.

+ 0

•0362

+ 0

•0674

+ 0-157

w.

+ 1

•0788

+ 0

•9992

+ 0 -059

+ 0-011

WNW.

+ 1

•1679

+ 1

•3622

+ 0 -483

NW.

+ 1

•2153

+ 1

•1573

+ 0-491

+ 0 032

NNW.

+ 1

1060

+ 1

3714

+ 0-663

N.

+ 0

•4746

+o

•2941

+ 0 375

+ 0 -049

NNE.

-0

•1140

-0

•1633

+ 0 076

NE.

—0

•1414

—0

•2329

+ 0-311

+ 0 018

ENE.

-0

•7890

—1

•1633

-0 097

E.

-]

•0911

—1

•2702

-0 -078

—0 -012

ESE.

—1

.2999

—1

•3935

—0 022

SE.

—1

•2090

-1

•1704

—0 -122

-0 049

SSE.

-0

•6924

—1

•1575

- 0 -386

S.

—1

•0057

—1

•1350

—0-515

—0 -048

SSW.

I-1

•1602 -1

•1306

-0 -500

The variations in Paris are calculated in millimetres for
twelve hours ; in the first 5 years the direction of the wind at
midday was observed, in the last 5 years the mean of the
entire day. The observations made at Danzig are variations
in sixteen hours expressed in Parisian lines; those made at
London in English inches from morning to evening, with-
out closer determination of the hour of observation. I have
omitted the inconsiderable correction for the daily variations
at Danzig.

The magnitude of the variation is in Paris for the morning
and evening observation,

In the 5 years —0-336 —0*01

In the 10 years —0*2785 +0*0075

In London —0*007 —0*002

a. The independence of the phenomenon on the daily periods
is evinced by the circumstance that the motion depending
thereon in the observations of Paris and London, is eliminated
by bringing them together with opposite signs. In Danzig
this independence follows from the circumstance (Pog. Ann.,
vol. xxxi. p. 477) that the variations from 6 o'clock in the
morning to 10 at night, coincide completely, as regards the
sign, with the variations from 10 at night to 6 in the morn-
ing.

b. The independence on the yearly periods is evinced by
the following table, which contains the motions in 12 hours

Prof. Dove's Outlines of a general Theory of the Winds. 357

from observations made at Paris for 10 years for the eight chief
winds.

Variations in Millimetres.

NE.

E.

SE.

S.

SW.

W.

NW.

N.

Correc-
tion.

Jan.

Feb.

March.

April.

May.

June.

July.

Aug.

Sept.

Oct.

Nov.

Dec.

-0-259
-0-365
+0-129
+ 0-317
-0267
+0-480
+0-944
+0-221

+ 0-454
+0-046
-1-238
+0-250

+ 1-336
-0-627
+0-842
+ 1156
+2-640
+ 1-276
+2144
+0-721
+ 1515
+ 1-273
+0-269
+0-182

+ 1-081
+ 1-273
+ 1-956
+ 1-301
+ 1-299
+ 1-509
+ 1-081
+0-775
+ 1-707
+0-381
+ 1-034
+0-982

+ 1141
+0057
+ 1-750
+0-274
+0-979
+ 1-999
+ 1-117
+ 1-333
+0-361
+0-419
+ 1-440
+2-333

+ 0-641
+1104
+ 1-004
-0-659
-0-449
-0 046
-0036
-0-550
+0-251
-0-188
+0-310
-0120

-1-400
-1040
-1058
-0-863
-0-486
-0-718
-0-762
-1-065
-1-732
-0-438
-0-796
—1-808

-2-842
-1-506
-2-869
-1-671
-0-321
-0-080
-1-477
-0-518
-0-324
-0-928
-1-656
-2-013

-0-684
+0-129
-0-964
-0-291

+0-478
+ 0-020

-0144
-0-566
-0053
-1-639
-2085
-1-208

0409
0-596
0-377
0-492
0-343
0-346
0-390
0-525
0-366
0-249
0-202
0-233

Year.

+0-233

+1-270

+ 1-170

+ 1-135

+0-208

—0-999

-1-157

-0-294

0-286

( — ) signifies rising, (+) falling.

The import of the signs is here the opposite to that of those in the
other table, in order that they should coincide with the monthly determi-
nations for Danzig.

The calculation mentioned under the former table for Dan-
zig, will be found in Pog. Annal., vol. xxxi. p. 468. It is,
however, known that the mean direction of the wind under-
goes a periodical change within the year, which will appear
from the following table, in which the angles, calculated
according to Lambert's formula, are enumerated from
south, as zero, towards west.

Paris.

Danzig.

Paris.

Danzig.

January ...
February ...

March

April

May

69°

50 57'

86 >7
109 27

61 42
118 49

89 56

90 18
66 53
22 45
52 32
40 1

50° 24'

60 19

84 20

120 53

141 30

138 29

107 22

82 43

71 46

37 16

54 47

48 1

wsw.

SW.

w.

WNW.
WSW,

WNW.

w.

w.

wsw.

ssw-

SW.
SW.

SW.
WSW.

W.
WNW.

NNW.

NW.
WNW.

W.
WSW.

SW.

SW.

SW.

June

July

August

September .
October ...
November .
December...

From the combination of the results of these two tablestt
follows, that the law of the rotation of the wind which is evinced
in the barometrical variations, is independent of the variations
of its mean direction.

.$58 Prof. Dove's Outlines of a general Theory of the Winds.

c. The independence of the law of rotation on the differences
of the yearly mean directions of the wind of individual places
will then first be accurately proved when we possess similar
observations for several places. The greatest difference among
the places of observation above mentioned amounts, in rela-
tion to the meandirection of the wind, to 30 degrees.

d. The rising and falling of the barometer with the various
winds is so closely connected with the mean distribution of the
atmospheric pressure in the wind-compass (the so-called ba-
rometrical wind-compass), that, if two maxima and two minima
occur in it, even in the intermediate wind there will be ob-
served a twofold rising and a twofold falling (Pog. Ann.,
vol. xxxi. p. 478.). It must however be observed that such
anomalies disappear much sooner in the rising and falling
than in the mean barometrical values of the winds (Pog.
Ann., vol. xi. p. 556). The barometrical mean conditions
observed during the influence of the wind acknowledge the
existence of a barometrical wind-compass, but deny the exist-
ence of the law of rotation, and may therefore be said to ac-
knowledge the phenomenon which evinces itself indistinctly
and rejects the one which is clearly evident.

2. The thermometer rises with E., SE. and south winds,
passes with SW. from rising into falling, falls with W.,
NW. and north winds, and passes with NE. from falling into
rising.

Observations for 5 years in Paris (1816 to 1820) give in 6
hours.

s.

-0-36 C.

N.

+006 C.

ssw.

-015

NNE.

+0-22

SW.

-0-62

NE.

+ 0-61

wsw.

-078

ENE.

+ 093

w.

-0-76

E.

+0-79

WNW.

—1-29

ESE.

+2-36

NW.

—013

SE.

+ 1-37

NNW.

-0*50

SSE.

+ 0-89

( + ) signifies rising, ( — ) signifies falling.

3. 4. That the variations of the pressure of the dry air is
in proportion to the barometrical variations, and the varia-
tions of the elasticity of the vapour, on the contrary, in pro-
portion to those of the temperature, will be evident from the
following table, which is deduced from observations in the
same years as the barometrical observations of London.

Prof. Dove's Outlines of a general Theory of the Winds. $59

Dry Air.

Elasticity of Vapour.

w.

+ 0"-011E.

0"000 E.

NW.

+ 0-039

-0 007

N.

+ 0 -063

—0 014

N.E.

+ 0 -023

-0 005

E.

-0 -002

-0 010

S.E.

-0 -055

+0 006

S.

-0 050

+ 0 -004

s.w.

-0-025

+0 -002

( + ) signifies increase, ( — ) decrease.

B. Hydrometeors — In three memoirs contained in these An-
nals (Poggendorff's) viz. " On the connection of hydrometeors
with the variations of the temperature and of the barometer,"
(vol. xiii. p. 305), "On thunder-storms," (vol. xiii. p. 419),
and "Some remarks on rain," (vol. xxxi. p. 541), I have
specially proved that the atmospheric precipitates depending
on the direction of the wind, whether they appear as rain,
hail, or snow, whether accompanied with disengagements of
electricity or not, are nothing less than a necessary conse-
quence of the law of rotation. Since there is at present no
reason to modify the positions laid down in those papers, and
as these may rather be extended to the southern hemisphere, if
we consider the line drawn on it from SE. to NW. as a line of
division of the west and east side, a repetition in this place of
what has been stated in them, seems to me quite unnecessary.

C. Currents which alternately expel each other. — In winter,
which is especially the time, when, on account of the greater
differences of temperature in the districts situated to the north
or south of the places of observation, all phenomena of weather
are for the greatest part occasioned by the wind, I have found
by comparison of the direction of the wind, as observed below,
with the passage of the higher clouds and the direction of the
finer fibres of the cirrus, that with SVV. and NE. winds the
under direction of the wind coincides with the passage of the
highest clouds; that on the contrary with W. and NW., with
E. and SE., the direction of the vane and of the lower cumu-
loid clouds is at right angles to the upper direction of the
wind. Besides this I have remarked, that when after a ba-
rometrical minimum with SW., the wind veers to the west,
and then goes round to north, dark mountainous cumulo-
strati advance from the western horizon immediately pre-
ceded by a cold wind, which raises the barometer, and which
in winter is combined with falls of snow, in spring with hail-
showers, and in summer with thunder-storms. This phseno-

360 Prof. Dove's Outlines of a general Theory of the Winds.

menon is in general very frequently repeated, while the cirrus
apparent in the superior regions of air through the interme-
diate space of the inferior masses of clouds continues un-
disturbed in its direction of SW. to NE. ; with each new pre-
cipitation the barometer rises by sudden jerks (sprungweise) ;
the inferior formation of clouds however continues gradually to
ascend ; at last the covering of the clouds breaks ; the cirrus
above disappears in like manner with a quick transit of the vane
through N. to NE. The vane remains at NE., the sky is en-
tirely clear, and the barometer as well as the cold have at-
tained their maximum. As soon as the barometer begins to
fall, fine cirri appear on the dark ground of the sky in the
direction of S. or SW. to N. or NE., which gradually con-
dense to that white envelope, which is admirably favourable
to the formation of halos round the sun and moon, which
therefore are justly regarded as signs of bad weather. The
vane indicates with falling barometer E. and SE., therefore
at right angles to the direction of the cirrus. If cumuli are
in the lower regions of the atmosphere, they are gradually
taken up by the evidently descending cirrus, and it then often
rains in winter when it freezes hard below. The vane passes
rapidly through S.; it rains as in general with a stormy SW.

From these observations I conclude: That there are two
opposite winds, which blow throughout the whole atmosphere.

These winds I call air-currents, the one the northern, the
other the southern. From the observations previously men-
tioned it follows that the phenomena of the west side are a
transition of the southern current into the northern ; and in
fact the driving out of the southern current b\' the northern
first takes place in the lower regions of the atmosphere, and
then in the higher. The phaenomena of the east side, on the
contrary, are a transition of the northern current into the
southern ; and the expulsion of the northern current by the
southern takes place first in the higher regions of the atmo-
sphere, and then also in the lower. Both westerly and easterly
winds therefore have often above them southerly ones; but
with the difference, that with west winds the upper direction
of the wind is driven out by the lower, with east winds the
lower by the upper.

The difference of the density of their masses of air, pro-
ceeding from the difference of heat in both currents, is the
cause of this phenomenon.

The more rapidly they expel each other, the stronger the
precipitates become during the transition of the one into the
other. The southern warmer current, in order to expel the
heavier northern one, must possess a considerable intensity.

Prof. Dove's Outlines of a general Theory of the Winds. 361

The greater this is, the greater also becomes the difference of
the rapidity of rotation of the places at which it arrives one
after the other.

The wind springs back more frequently between S. and W.
on the northern hemisphere than between N. and E. ; and
the more frequently also, the more violently it rages.

If the southern current has prevailed for some time exclu-
sively at one place, and if it is finally expelled by a colder,
and therefore denser polar current, this takes place with
greater violence. Violent storms therefore pass from SW.
through W. into NW. First, then, when the wind becomes
N. and NE., its violence decreases. The extremes of mete-
orological instruments do not coincide with N. and S., but
rather with NE. or E. and SW. or W. Then, as for instance,
the NE. is properly a north which comes from more northern
regions than the N. it must be colder, drier, and heavier than
the latter, &c. The individual character of single periods is
occasioned by these currents. Its occurrence in the southern
currents (an excess of SW. and W. winds) brings mild winter
and coldsummer, with frequent and considerable precipitations;
its occurrence in the northern current, on the contrary, causes
a cold winter and hot summer with great dryness. In the
first case the warm equatorial air, which rushes towards the
pole, advances into higher and higher degrees of latitude, its
capacity for vapour continually diminishing; and thus it loses
its vapour by continually repeated precipitations. In the second
case, however, the cold air of the quietly flowing northern
current comes gradually into lower degrees of latitude ; its
capacity for vapour gradually rises, and during the continu-
ance of this current, the sky remains serene as with a NE.
trade wind.

If the two currents meet one another, not at a greater or
smaller angle, but lie exactly opposite each other at their
meeting, they concuss one another often for a long time. If
the currents possess no considerable intensity, there originates
at the place of their meeting, especially in autumn and winter,
a thick fog, which frequently disappears all at once, and re-
appears, accordingly as the place of observation is situated on
the northern current, or on the boundaries of the southern one.
If the southern current is of considerable violence, it flows
above the opposing northern current, and prevails in the upper
regions of the atmosphere, while in the lower regions there
is a calm. The barometrical minimum here observed will
find its explanation in the dreadful storms which prevail in
southern districts. Barometrical maxima arise from a jostling
of the northern current with the southern opposing one.

Third Series. Vol. 1 1. No. (58. Oct. 1837. 3 A

362 Prof. Dove's Outlines of a general Theory of the Winds.

It is evident that since an equilibrium so produced cannot be
a lasting one, barometrical maxima and minima lie in general
close to each other : such irregularities generally, after various
previous oscillations, balance each other.

If the equatorial currents be detained by a high land situ-
ated in the south, the quiet and dry sea of air of such districts
will be moved principally by the influx of waves of the west
and east winds traversing the parallels. Besides it is evident
that the number of east winds will here increase, while the
number of west winds will decrease.

The range of the barometrical oscillations of such districts
can be but very small.

The necessity of the origin of equatorial currents in the
temperate zones has already been treated of in a former me-
moir on monsoons and trade winds. The frequent occurrence
of the SW. winds in comparison with the southern wind is a
proof that the equatorial currents, when they are first observed
at the surface, could not have originated there, but must have
come down from above. M. von Buch has also mentioned
in support of this view, proposed by Halley, such convincing
reasons, grounded on observations made at the Peak of Te-
neriffe, that it has been received by almost all naturalists. The
necessity of such westerly winds following from the constancy
of the rapidity of rotation of the earth has recently been
made so evident by Herschel, jun., that it will be proper to
cite here the words of the author.

" The constant friction thus produced between the earth
and atmosphere in the regions near the equator must (it may
be objected) by degrees reduce and at length destroy the ro-
tation of the whole mass. It is easy to see in the present
case where and how the compensation takes place. The
heated equatorial air, when at length it returns to the surface,
in its circulation, which it must do more or less in all the in-
terval between the tropics and the poles, will act on it by
its friction as a powerful south wind in the northern hemi-
sphere, and a north-west in the southern, and restore to it the
impulse taken up from it at the equator."

The view developed in this memoir respecting the phe-
nomena relative to wind which occurs in the temperate zones,
removes, if I mistake not, the objection raised against the
theory of the trade-winds, that the influence of the rotation of
the earth could not be so considerable in the latitudes in which
they prevail, because it must be much stronger in higher de-
grees of latitude than between the tropics. The objection
in effect is none, for I think I have demonstrated that that
which is required does really exist. We can also easily ac-

Prof. Forbes on Terrestrial Magnetic Intensity, 363

count for the fact, that, if we pass from Southern Europe to
Northern, the westerly winds generally prevail at the expense
of the south-westerly.

For the positions stated in C, proofs will be found in some
of my previous memoirs. They might be considerably aug-
mented in number, which however does not seem to me ne-
cessary.

XLV. Account of some Experiments made in different Parts oj
Europe, on Terrestrial Magnetic Intensity ', particularly with
reference to the Effect of Height. By James D. Forbes,
Esq., F.Il.SS. L. $ E., $c, Prof. Nat. Phil, Edinb.

[Continued from p. 260, and concluded.]

30. TJUT to return to the calculation of the first group of
-*-* observations, those including the alpine country of
Switzerland, Savoy, and Italy. If we arrange the observations
relatively to Geneva as a fundamental station, taking the data
from Table VII. and writing the equations of condition in the
form (3.) art. 28, where ax denotes the excess of northern
latitude of the given station above that of Geneva in minutes;
bx the excess of eastern longitude in minutes of a degree ; cx
the excess in height, reckoned in hundreds of English feet in
round numbers (using of course negative signs to represent
the reverse of all this), we shall have the following equations
of condition, distinguishing from one another the absolute
numbers obtained by the two needles, in order that they may
be separately calculated.

Table VIII.
Equations of Condition for the Alpine Series.

By No. I. By <« Flat."

Geneva (Aug. 1832) 0'*+ <fy+0'z+3r = -002 -005

Geneva (Nov. 1832) 0*+ 0#+ Oz+dl' = — '002 — 005

MontSaleve — 6*+ 2<y+32z+M' = -001 -002

MontBreven — 16*+ 41 y+7\ z+l V = -013 -024

5. Chamouni — 17*+ 43y +21 z + S I' = -009 -005

Jardin -17*+ 50^+77 z+SI' = -007 009

Col des Fours —27*+ 36#+76z+S I' = -012

Aoste —28*+ 71y+ 6z+SI' = -020 '018

St. Bernard —20*+ 61^+68«+8I'= "006 000

lO.Martigny — 6*+ 56#+ 3z+BI' = -007 '004

Interlaken 30*+103#+ 6z+ll' = — 008 —'009

Schmadribach .... 19*+104j/+39z+dl' = -003 —'002

Grir.delwald (1.) .. 26*+ 1 13^+24 z+lV = —001 000

Grindelwald (2.) .. 26*+113y+21 z+lV = — 004 '007

15. Meyringen 32*+ 123^+ 7 z+ IV =—001

Grimsel 22*+ 130^+49 z+d 1' = —002 —007

Munster 18 *+ 128^+29 z+ 3 I' *= -002 — 003

3 A2

364.

Professor Forbes's Experiments on
Table VIII. — {continued* )

ByNo.l,

Gemini 13*+ 88.y+ 62z+S 1' = -002

Friitigcn 24*+ 89^+10 z+H' = --003

-•005

20 Faulhorn 28.r+lll#+76z + o- 1'

Engelberg 37 x+ 138^+21 z+S I' = —005

Surennes 37-r+]443,+64z+B I' as — 005 — -009

Klus (near Altorf).. 37*+150<y+ 3z+lV = —004 --010

St.Gothard 22x+145^+ 58z+S I' = — -005 --009

25.Locarno — 2x+159y— 6z+%V = -008 -008

Orta _25.r+135y— 3z + 3I' = '016

Bellagsrio _12*+187#- 6z+lV = '019 -019

Reichenau 37*+195^+ 7z+SI' = -000

Wallenstadt 55*+19ly+ z+M' = — *007 —'008

30.Lucerne 51 *+130y+ 2z+d I' = — 008 — -013

Rigi-Culm 51 x+ 140^+46 z+l V = —'014

31. From these thirty-one equations of condition for needle
No. I, and twenty-four for the flat needle, we obtain by the
method of least squares the following values of the four un-
known quantities, the calculations having been verified by in-
dependent methods.

By "Flat."
-•00£

-011

No. I.

—000364

x = Variation of intensity for V of latitude N \

increasing J

y = Variation of intensity for 1' of longitude \

E increasing J

z = Variation of intensity for 100 English feet )

of height /

1 1' = Correction applicable to the registered "I i.nnif?
Geneva J '

+•000055
—000033

Flat.
—000505

—000106

—000027

—0040

intensity at

32. To deduce from these numbers the lines of equal hori-
zontal intensity, we must remark that the minute of longitude
is shorter than the minute of latitude in the ratio of 7^ to 10
nearly, on an average, in the Alps. The variation of y for
a geographical mile or minute would therefore be

For No. L = + -000076. For " Flat" = + -000146.

And the angle made by the isodynamical lines with the meri-
dian towards the east from north would be

Arc whose tang. = — — , and arc whose tang. = — -

76 ° 146

= 78° 12' and 73° 52'.

33. Of these results I conceive that the former is to be pre-
ferred. The discrepancy of the results obtained by No. I.
and " Flat" are, I presume, attributable to one or both of two
causes, — a progressive change in the magnetic state of the
needle somewhat different from what has been allowed for, —
and a slight error in the correction for temperature, which,
during the period of observation (the autumn), was generally

Terrestrial Magnetic Intensity. 365

diminishing. Now both these points being best ascertained
for No. I., I prefer abiding by its indication. In fact, it ap-
pears by Table VII. that the intensity of the flat needle de-
creased from August to November (by the Geneva observa-
tions) faster than the mean rate of decrease allowed; the con-
sequence of which would necessarily be, that the standard in-
tensity at Geneva for purposes of comparison would be as-
sumed too high, and, as the general order of the observations
lay southward and eastward, the apparent increase of intensity
in those directions would be smaller than the true, which would
give rise to an error of the kind mentioned in Art. 31. The
stability of No. I. renders its indications the most certain. The
agreement as to the effect of height is very satisfactory, con-
sidering the minuteness of the quantity. The source of error
just alluded to would scarcely affect this result. The most
probable intensity for Geneva will be 1-0776 for No. I.*, and
1*0670 for the flat needle. The results are projected in the
mapf.

34. The observations in the Pyrenees lie within smaller
compass, and were chiefly conducted with a view to deduce
the influence of height. The sources of local error arising
from metalliferous deposits are, however, perhaps greater in
this case.

35. Proceeding exactly as before, taking Luz in the valley
of Lavedan or Bareges, Hautes Pyrenees, as our point of re-
ference, we obtain the following equations of condition from
Table VII., which may be arranged exactly as in Table VIII.
incorporating the results of both needles. In this case the
longitudes being westerly, the variation in longitude must be
reckoned the opposite way from that in the former case.

Table IX.
Equations of Condition for the Pyrenean Series.

Luz(l.) 0'*+ 0'y+ Oz+ai'= -000

Luz(2.) 0x+ Qy+ Oz+lV = — 001

Ste Marie 8*— 13y+ 4s+H'= — -004

Pic du Midi Ax- Qy^2z-\-lV = — 005

Picde Bergons(l.) — x— 2y+A5 z + Sl' = —-010

(2.) — x— 2y+45* + 3I' = — -010

Gavarnie — 8*+ y+21 z+ZV = +-001

Breche de Roland — 10.T+ 0^+69 z+S I' = --001

36. Combining these by the method of least squares, we
obtain the following values : —

x — — '000210

jjrss + -oooioo

z = — -000053
I T s» — -0028.
• The intensity varies 01 for 27'5 of latitude. f See p. 375.— Edit.

3(>6 Professor Forbes's Experiments on

Hence it appears, that on the same parallel of latitude the
intensity increases in a westerly direction, which is the reverse
of the result found for the course of the isodynamic lines in
the Alps; but, in truth, I do not attach much importance to
these observations, unless for the sole consideration of height,
on account of the small area of country over which the obser-
vations were made. There were probably in the Pyrenees
some sources of local disturbance which the observations on
the Pic de Bergons particularly indicate, and which, having
been repeated with coincident results, could not be owing to
an error of observation*. At the same time it is satisfactory
to find that the influence due to height is the same in direc-
tion, though greater in amount than that obtained in the alpine
series. On this subject I proceed to offer some remarks.

37. The first experiments which seem to have had even
remotely in view the question of the decrease of magnetic in-
tensity with height are those of Saussure, made during his
memorable stay on the Col du Geant in 1788. The observa-
tions were too rude, and differ too widely from each other to
deserve much confidence; but those made at Chamouni and
on the Col du Geant, which were fortunately under almost
the same temperature, agree very closely, but give a slightly
greater intensity to the latter, which is the effect due to the
latitude |\ The great diminution of intensity in going from
Geneva to Chamouni, observed by Saussure, is certainly er-
roneous, as the reverse has been shown to take place.

38. In 1804 M. Gay-Lussac performed his celebrated
aerostatic ascent, and from his magnetic observations con-
cluded that no appreciable difference of intensity existed at
the surface of the earth and at the height of 23,000 feet. This,
however, can only be considered as referring to great and
palpable change. The difficulties inseparable from the ex-
periment prevented many oscillations from being observed,
or great precision in the times from being attempted, whilst
corrections for arc, diurnal variation, and temperature, were
not applied. The last of these, however, could hardly fail to

* Since this passage was written, on mentioning to Professor Necker of
Geneva the anomalous result as to the direction of the isodynamic lines
in the Pyrenees (anomalous, decause differing from the supposed direction
inserted in Hansteen's map, which is deduced from analogy, and not, J be-
lieve, from direct observations in that country), he pointed out the curious
(though perhaps accidental) coincidence which this result offers to the
views he has long entertained as to the general parallelism of the lines of
geological elevation, and those of magnetical intensity, which the bearing
of the isodynamic lines which I have given for the Alps remarkably con-
firms.

t Saussure, Voyages aux Alpes, § 2103. Tom. iv.

Terrestrial Magnetic Intensity. 367

be sensible, the variation of temperature being no less than
36° Cent., and as cold tends to increase the apparent intensity,
if no such increase was observed, it might plausibly be argued
that the real intensity had diminished. It must, however, be
observed, that the observations lasted only in general from
one to two minutes, and that in so short a period (and de-
pending on a single value of the elapsed time) the accelera-
tion due to the above-mentioned cause would hardly be per-
ceptible. Taking the mean result of the effect of temperature
ascertained by myself for No. I. and " Flat" needles, we find
the factor —'00037 applicable to the time for a decrease of
1° R. of temperature, which agrees exactly with Hansteen's
mean correction. If we apply this to Gay-Lussac's observa-
tion we find a correction of —•0108 as a factor applicable to
the time, for the effect of —36° Cent, of temperature. Yet
large as this is, amounting to T£oth part of the whole, the
discrepancies of observation often amount to double that
quantity*. Still we admit with M. Kupffer that the probabi-
lity deducible from M. Gay-Lussac's observations, is in favour
of a slow diminution.

39. The next series of observations includes those of Hum-
boldt and Gay-Lussac, recorded in the Memoir es d'Arcueilf,
which include observations made in the Alps, though at no
great heights; and here no particular influence of height was
observed, nor was indeed looked for J.

40. Since that period the subject seems to have met with
little practical attention, until the recent publication of M.
Kupffer' s " Voyage au Mont Elbrouz" by the Petersburg
Academy. From his observations with a needle by Gambey,
half a metre long, M. Kupffer attempts to deduce, not only
the fact, but the amount of the diminution with height, and
this upon the authority of a single experiment, and at no con-
siderable elevation §. In fact, all the intricate corrections
which this delicate observation requires were little more than
guessed at. The difference of geographical position of the
two stations (19/ in lat. 38' in long.) was allowed for by ob-
servations made with a different apparatus, — the effect of
temperature was deduced from indirect experiments, far from

* See the details of the observations in the Annates de Chimie. An xiii.
(1805), torn. lii. p. 75. f Tom. i. p. 1. \ Ibid. p. 10.

§ The observations were not made at the summit of Mont Elbrouz, as
stated in the Annuaire du Bureau des Longitudes, 1836, p. 288, but near the
foot of it, and the difference of height of the stations was less than 5000
English feet. The stations were " Pont de Malka," and " Hauteur de
Kharbis."

368 Professor Forbes's Experiments on

presenting a mutual agreement ; and the whole difference of
level (4500 French feet) offered a very small basis for so ge-
neral a conclusion. But, besides this, there is an oversight
in M. Kupffer's deductions (first pointed out to me by Pro-
fessor Necker of Geneva), which tends yet further to diminish
the probability of his conclusions. The estimate of the effect
of geographical position on the magnetic intensity, M. Kupffer
conceives to be such, that the variation for 12' in lat. (dimi-
nishing from the lower to the upper station) would exactly
counterbalance the variation due to 38' in E. long, (also di-
minishing from the lower to the upper station); the one in-
creasing the duration of an oscillation as much as the other
diminished it. Now it appears from his own statement on the
preceding page (Memoir, p. 87), as well as from the known
direction of the isodynamic lines, that these variations con-
spire with one another, so as to render the anomaly attributed
to height greater than before. The upper station is S.W. of
the lower, the direction of the isodynamic lines is from N.W.
to S.E., consequently the variation of position is such as would
diminish the time of vibration of the needle, whilst in effect it
was found to be increased. From M. Kupffer's data, I find
that the time of one vibration of his great needle by Gambey
(24s,05 nearly) would be diminished about 0S,104 for the
change of latitude and longitude, whilst it was observed to
be increased by 0S,063. The anomaly, then, instead of being
0s -063, as M. Kupffer states it (and which he attributes to the
effect of 4500 French feet of elevation), would be 0S,167, or
nearly three times as great. M. Kupffer's law of an increase
of '000583 of the whole time of vibration, for a rise of 1000
French feet, will therefore, when corrected, amount to '00155,
and the factor for the diminution of intensity to twice as much,
or *0031, which is just ten times as great as my observations
indicate, and is so considerable, that, were the conclusion just,
it could not fail to be detected by the most ordinary instru-
ments at the most ordinary elevations.

41. But if the anomaly be admitted to exist in M. Kupffer's
observations, whence does it arise? I have no difficulty in
answering the question. I shall not dwell upon the incom-
plete data from which the corrections due to temperature,
latitude, &c. are derived ; nor upon the entire incompetency
of a single observation, which unknown causes (for instance,
an iron mine, or the occurrence of an aurora borealis) may
affect. I take M. Kupffer's own statement in the geological
section of his work, which pronounces the whole country sur-
rounding Mont Elbrouz to afford one continued evidence of

Terrestrial Magnetic Intensity. 369

ancient volcanic eruption*, to abound in hot ferruginous
springs-)*, to be so intersected by trachytes:}:, lavas J, and
diorites||, that there is distinct evidence of this tract being
nothing else than a crater of elevation, raised by the uphea-
ving force of the trachyte of Mont Elbrouz itself f, which he
states to be undistinguishable from the rock of Pichincha, the
great South American volcano**. Any one who has the
slightest acquaintance with the connection between magnetism
and volcanic rocks will be at no loss to explain anomalies even
greater than those which M. Kupffer has observed.

42. It was from a persuasion of the entire inconclusiveness
of M. Kupffer's results, as well as of all preceding ones, that
I undertook the experiments already detailed, in the hope of
compensating for the imperfections of the apparatus by the
number and extent of the experiments. I own that until I came
to calculate the results by the method of least squares, I had
little confidence in having obtained any positive result. A
careful examination of the station marked on the map, will
show that they were almost invariably chosen so that an ele-
vated station lay between two others at a lower level, by which
the effect of change in latitude and longitude might be elimi-
nated. When we criticize these groups of three series, we
find for the most part an agreement greater than I had my-
self anticipated that the instrument could insure ; yet the com-
bination of all with two independent needles, and likewise in
two series in different countries and difFerent years, unite in
giving a negative coefficient to the height, which I believe to
be true and not accidental, though it could not safely be in-
ferred from one or two insulated observations. I should be
disposed to deduce its probable value thus, taking the circum-
stances of the observations into consideration :

Coefficient of Varied Intensity
Weight. for 100 feet of Elevation.
Alps, Needle No. I. ... 4 -000033

Alps, Flat Needle 2 -000027

Pyrenees, both 1 -000053

Probable mean -000034
Hence to produce a variation of -001, an elevation of 3000
feet is necessary. At the height to which Gay-Lussac ascended,
the change of intensity would be nearly -008 of the whole ; but

* Voyage, p. 39. t P- 39, p. 44, p. 55. % P. 44, p. 61, p. 65.

§ P. CO, p. 66. || P. 63. 1 P. 65. ♦* P. 35.

Third Series. Vol. 11. No. 68. Oct. 1837. 3 B

370 Professor Forbes's Experiments on

the variation in the time of an oscillation would be only half
as much.

4S. The smallness of the variation fully explains the diffi-
culty of ascertaining its existence from a very limited number
of observations. It is hoped that, notwithstanding the im-
perfection of the instruments, the extent of the induction will
entitle the result to some confidence. By adding together
the elevations of the distinct stations contained in Table VII.
it will be found that the aggregate of the heights to which I
have ascended amounts to above 160,000 feet, or more than
thirty vertical miles.

% 5. On the Magnetic Dip,

44. Although the horizontal magnetic force be only a sort
of mathematical abstraction, and bears no direct relation to
the earth's action until the effect of dip is considered, we do
not therefore think it improper to be made a separate subject
of inquiry. From the projected lines of equal horizontal in-
tensity and of equal dip, the lines of equal total intensity are
deducible. The two elements may therefore be made the sub-
ject of distinct inquiry; and though these elements are pro-
bably in a condition of continual change, yet, considering the
present errors of observation, any moderate lapse of time be-
tween the formation of these curves will not be productive of
serious anomalies. By deducing the total intensity curves
from the two partial sets of curves, we also increase the pro-
bability of accuracy, since intensity is likely to be so much
oftener observed than dip; that the lines of equal horizontal
intensity will be better determined than if those points alone
were used where the dip was also observed ; and thus the
whole acquires additional consistency.

45. The general relations of dip and horizontal intensity
have been pointed out in the excellent charts of Hansteen.
Though it is very probable that mountain chains may cause
inflections in the general course of the curves, and local at-
tractions produce occasional anomalies, yet the general varia-
tion of one or other quantity is always graduated ; and though
an insulated observation may be spoiled by an abrupt change
in either element, the conclusion from a series of experiments
cannot be so affected.

46. I state this chiefly to meet two objections to conclusions
from experiments of the kind I have detailed, which have at
different times been urged. The first is, that the influence
of height (for example) upon the horizontal intensity may not
be due to a change in the total intensity, but only of the dip.

Terrestrial Magnetic Intensity. 371

To this we would reply, that no reason can be assigned why
the dip should more naturally vary than the intensity; and
that it is contrary to all probability that the variation in the
latter should be wholly due to the indirect influence of the
former. We admit that the change may be due to both
causes conjointly; but further, if we adopt Humboldt's esti-
mate (I quote from a reference which I have been unable to
verify), which assigns a diminution of 2,#5 of dip for 1000 feet
of extent, we should have an apparent increase of horizontal
intensity, if the total intensity remained constant. The second
objection to which I alluded, I believe no one accustomed to
treat such problems will apply to my observations after due
examination, namely, that though three stations be in one
straight line and equidistant, the elevated station being in the
centre, we can draw no conclusion as to the variation of the
intensity by comparing the extreme observations with the
middle one, because the dip may have altered in the interval.
We may indeed have, by a strange accident, a solution of
continuity which might produce this effect in a single instance,
but its capability of affecting a whole series of observations
cannot for a moment be sustained.

47. Observations of dip I have not, however, neglected.
My instrument was a very small one (three inches diameter),
constructed by Mr. Robinson for the late Captain Kater, and
incapable of indicating such small variations as are required
to fix with great accuracy the lines of equal dip. Nor can I
hope that the small number of observations which I have ac-
cumulated can throw any light upon the influence of height
on the dip. Still these observations may fix the dip at several
stations with considerable accuracy, and the collation of them
shows that tolerable precision may be attained even with an
instrument of very small dimensions. Had the observations
been as much multiplied as those of intensity the isoclinal
lines would, even by this instrument, have been determined
with very considerable exactness. The following table con-
tains observations made with only one needle (marked No. II.),
the other (from having too thick an axis) having been found
to give much more anomalous results.

3 B2

372

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374 Professor Forbes on Terrestrial Magnetic Intensity,

48. A careful review of these observations, compared to
those of the usual dipping needles, gives, I think, a favourable
impression of the powers of a small instrument. The obser-
vations were put in the form of equations of condition for
the alpine series, exactly as in the case of intensity ; x re-
presenting the variation of dip in minutes for lf of latitude N.
increasing; y the variation for 1' of longitude E. increasing;
z the variation for 100 feet of height. Geneva is taken for
the standard of comparison as before ; 8 A ' representing the
correction of the dip at that place.

Table XL

Equations of Condition for Dip.

Geneva 0'* -f O'y + 0 z + S A' = 0'

Cologny .... 0* + 2y + 3 z + 3 A' = — 8

Breven —16* + 41 y + 71 z + S A' = — 11

Chamouni .. —17* + 43 y + 21 z + & A' = — 5

Jardin —17* + 50 y + 77 z + I A' = — 7

Aoste — 26**+ 7ly + 6z+&A' = — 18

St. Bernard.. —20* + 61 y + 68 z + d A' = — 10

Martigny .... — 6x + 56y + 3« + 3A'= — 26f

Bex 3* + 52 y + z + $A'= — 5

Interlaken .. 30* +103 y + 6 z + 3 A' = 17

Interlaken .. 30* + 103 y +62 + & A' = 20

Hospital .... 24* + 135 y + 36 z + & A' = 21

St.Gothard.. 22* + 145 # + 58 z + 3 A' = 5

Locarno.... — 2* +159 y — 6 z + I A' = —5

Pfeffers 47* +200 y + 17 z + 5 A' = 4

49. The method of least squares gives us from these equa-
tions the following values of the unknown quantities: —

x = 0'*543 y = - 0''028 z = 0''080 8 A' = — 3'-4.
As already stated, I consider these numbers (particularly z$
which gives an increase of dip of 1' for 1250 feet of ascent) as
considerably uncertain.

50. If the variation of y for 1' of longitude, be increased
in the ratio of the length of 1' of latitude to 1' of longitude (as
in Art. 32), it will become = — 0'*039, and the direction of
the isoclinal line to the east of north will be

Arc whose tang. = — - = 85° 53'.

Hence the lines of equal dip would appear to approach nearer
to the parallels of latitude than the lines of equal horizontal
intensity (Art. 32). The corrected dip at Geneva would be
65° l'*6, and the dip would increase 10' for an increase of
18'-4 of latitude.

* The coefficient ought to have been 28.

f This observation is certainly erroneous, and should have been dis-
carded.

Dr. J. Reade on a permanent Soap-bubble. SI 5

51. The lines of equal dip and equal horizontal intensity
being known, the direction of the lines of equal total intensity
may be deduced geometrically. I am, however, too well aware
of the great uncertainty which a small error in the elements
produces, to attempt to assign a result which might prove very
erroneous indeed.

Postscript. — Since this paper was written, and the results
made public, a suggestion has been made in a quarter entitled
to attention, as to now far the apparent diminution with height
may be due to the hour of the day at which observations at
great heights have usually been made. I have already stated,
that I have attempted no correction for the hour of the day,
owing to the want of accurate data, but I thought it worth
while to inquire how far there was any general ground for
such an explanation of the observed difference. I accordingly
divided my observations into 18 series above 4-000 feet, and
22 below that height. I found that the mean hour at which
the former were made was llh 12m, the latter at 12h 42m.
According to the best observations, the intensity would be
somewhat less at the former period than the latter, and would
so far give a false indication of diminished intensity with height.
But the variation for lh 40m would undoubtedly be trifling,
compared even with the small variation which the preceding
paper assigns for 5110 feet, which corresponds to the mean
difference of height for the two series, the mean height for the
first being 7160 feet, and for the second 2050.

[Prof. Forbes's paper, as printed for the Transactions of
the Royal Society of Edinburgh, is accompanied by a " Map
of the Central Alps," shewing the lines of equal horizontal
magnetic intensity, and equal dip, in 1832. As the magnetic
lines in this map have been projected entirely from the obser-
vations recorded and discussed in the paper, we have deemed
it unnecessary to copy it. — Edit.]

XL VI. On a permanent Soap-bubble, illustrating the Colours
of thin Plates. By Joseph Reade, M.D.*

IVTO subject in natural philosophy has more engaged the
^■/j attention of the learned than the discovery of a perma-
nent soap-bubble. Mr. Boyle, Dr. Hooke, and Sir Isaac
Newton were among the first, Dr. Herschel and Sir David
Brewster among the last experimenters. After such characters
it may appear presumptuous to enter the lists unassisted by

• Communicated by the Author.

376 Dr. J. Reade on a permanent Soap-bubble,

novelty of experiment ; I therefore rest my claims principally
on that ground, and hope in this paper that the reader may find
that interesting subject simplified. The first account of the
colours produced by thin plates is to be found in Mr. Boyle's
works : " To show the chemist that colours may be made to
appear or vanish, where there is no accession or change either
of the sulphureous, the saline, or the mercurial principles of
bodies, he says that all chemical essential oils, as also good
spirits of wine, by shaking till they rise in bubbles, appear of
various colours, which immediately vanish when the bubbles
burst, so that a colourless liquor may be immediately made
to exhibit a variety of colours and lose them in a moment
without any change in its essential principles: he then men-
tions the colours that appear in soap-bubbles, and also in tur-
pentine. Me sometimes got glass blown so thin as to exhibit
similar colours." Here we may remark, that although Mr.
Boyle did not advance any theory from these experiments,
yet it is evident that he connected the production of colours
with the thinness of the substance, as appears from his en-
deavours to blow glass sufficiently thin. This suggestion in
all probability afterwards gave the idea to Dr. Hooke, and
finally to Sir Isaac Newton, who has, the merit of clothing
Hooke's suggestion in a mathematical dress, beautiful and
interesting in the extreme.

Dr. Hooke was the next to investigate this subject; at a meet-
ing of the Royal Society, 7th March 1672, he promised to ex-
hibit at their next meeting something which had neither reflec-
tion nor refraction, and yet was diaphanous ; he then produced
a bubble of soap and water. It was no wonder that so curious
an experiment should excite the interest of one of the most
learned, liberal and scientific societies in Europe; they re-
quested him to bring an account of it in writing at their next
meeting. " By means of a glass pipe he blew several small
bubbles out of a mixture of soap and water, when it was ob-
servable that at first they appeared white and clear, but that
after some time the film growing thinner, there appeared upon
it all the colours of the rainbow, first a pale yellow, then
orange, red, purple, blue, green, with the same series of co-
lours repeated." Sir Isaac Newton's experiments as exhibited
in his Optics are so well known, that I shall not enumerate
them in this paper, merely remarking that his bubble was so
evanescent that it burst before he had time to make an
accurate examination. Melville of Edinburgh thought to
make a permanent soap film by means of freezing. This was
impossible. It occurred to me that by taking off the atmo-

illustrating the Colours of thin Plates, 377

spheric pressure 112 pounds to every square inch, I might
accomplish my purpose ; I therefore made the following ex-
periment.

Exp. — Having put two ounces of distilled water into an
eight-ounce phial, and having added about the size of a large
pea of Castile soap, I placed the bottle in a saucepan of
boiling water on the fire; the bottle was speedily filled with
a dense volume of vapour, which expelled all the air. I now
corked it, and after cooling, and thus condensing the vapour,
had perhaps as perfect a vacuum as could be formed, even by
the best air-pump*. I now held the bottle laterally between
my hands, and by means of a circular and brisk motion formed
a circular film, on which by resting the bottle on an inclined
plane, were formed after a short time all the parallel bands or
series of colours in the following order: 1. a white or silvery
segment at top; 2. a snufF-colo tired brown inclining at bottom
to a deep red; 3. blue; 4. yellow; 5. red; 6. blue; 7. green;
8. red; 9. green; 10. red; 11. green. (See Figures, p. 378.)

After some time a black segment was seen to form at the top
of the white and continually to increase in size. After a few
minutes the parallel bands increased in breadth, and running
into one another only three or four distinct bands were seen.
Nothing can exceed the beauty of these colours, equal to those
of the rainbow, or theplumage of the tropics: whilst writing this
description I have these bands in a bottle before me, feasting
my eyes on their beauty. In a few minutes more this black
segment or aqueous film occupies, perhaps, half the circular
film, and the lower half becomes white tinged with orange.

If we now incline the bottle towards the experimenter's
breast, the saponaceous atoms producing these colours are
seen to float in the region of the black or aqueous : when
placed again on the inclined plane they fall to the bottom of
the films. In some time more the entire film becomes black,
and all the colours disappear.

Having now placed the bottle in a basin of boiling water
the evaporation was increased, and the black film soon be-
came clothed with saponaceous atoms, which being variously
condensed produced all the colours of the clouds when the
sun is setting on a summer's evening. On again placing the
bottle on the inclined plane the parallel bands were again
formed by the attraction of cohesion, and the colours afterwards
gave place to the black film. I held the bottle laterally be-

* This vacuum, we apprehend, may be vitiated by the entrance of at-
mospheric air through the cork, indicating the necessity of covering it
with cement. — Edit.

Third Series. Vol. 1 1. No. 68. Oct. 1837. 3 C

378 Prof. Locke on a ?iexv Thermoscopic Galvanometer.

tween my hands, and by means of a circular motion washed
it, and thus clothed it with saponaceous atoms, which went
through the same process on placing the bottle on the in-
clined plane. By means of washing the film every morning,
I preserved it for more than three weeks. This simple experi-
ment opens a wide field of investigation to the natural philo-
sopher, and enables him at his leisure to examine the in-
teresting phaenomena of these colours.
London, Sept. 4, 1837-

1. 2. 3.

Black.

White.

[Since the date of the above paper we have received a com-
munication from Dr. Reade, stating that on the 14>th of Sep-
tember he exhibited the mode of preparing a permanent
soap-bubble before the Section of Physics at the meeting of
the British Association at Liverpool, Sir D. Brewster in the
chair. — Edit.]

XL VI I. On a large and very sensible Thermoscopic Galvano-
meter. By John Locke, M.D., Professor of Chemistry in
the Medical College of Ohio,

To Richard Taylor, Esq.
Dear Sir,

rT,HE announcement of a new galvanometer will, perhaps,
-■• scarcely attract attention. But as I have. been kindly
encouraged by several eminent British philosophers to com-
municate some notice of my modification of the thermo-mul-
tiplier, I venture to send you the following sketch. Although
a great labour has already been performed in electricity and
magnetism, yet the adepts are aware that much remains to be
executed, and that among the numerous principles already
clearly established, it is probable that those proportions and
arrangements which will produce the maximum effect have
been in few instances fully ascertained. The chief novelty
of the instrument which I am about to describe, consists in its
proportions and the resultant effects. The object which I

Prof. Locke on a new Thermoscopic Galvanometer. 379

proposed in its invention was to construct a thermoscope so
large that its indications might be conspicuously seen, on the
lecture table, by a numerous assembly, and at the same time
so delicate as to show extremely small changes of tempera-
ture. How far I have succeeded will in some measure ap-
pear by a very popular, though not the most interesting ex-
periment which may be performed with it. By means of the
warmth of the finger applied to a single pair of bismuth and
copper disks, there is transmitted a sufficient quantity of elec-
tricity to keep an eleven-inch needle, weighing an ounce and
a half, in a continued revolution, the connexions and reversals
being properly made at every half turn.

The greater part of this effect is due to the massiveness of
the coil, which is made of a copper fillet about fifty feet long,
one fourth of an inch wide, and one eighth of an inch thick,
weighing between four and five pounds. This coil is not
made in a pile at the diameter of the circle in which the
needle is to revolve, but is spread out, the several turns lying
side by side, and covering almost the whole of that circle
above and below. The best idea may be formed of the coil
by the manner in which it is actually modelled by the work-
man. It is wound closely and in parallel turns on a circular
piece of board eleven and a half inches in diameter and half
an inch in thickness, covering the whole of it except two small
opposite " segments" of about 90 degrees each. The board
being extracted leaves a cavity of its own shape to be occupied
by the needle.

The copper fillet is not covered by silk or otherwise coated
for insulation, but the several turns of it are separated at
their ends by veneers of wood just so far as to prevent con-
tact throughout. In the spreading out and compression of the
coil it is similar to Melloni's elegant apparatus; though in my
isolated situation in the interior of America I was not ac-
quainted with the structure adopted in his prior invention.
In the massiveness of the coil my instrument is perhaps pecu-
liar, and by this means it affords a free passage to currents of
the most " feeble intensity," enabling them to deflect a very
heavy needle. The coil is supported on a wooden ring fur-
nished with brass feet and levelling screws, and surrounded
by a brass hoop with a flat glass top or cover, in the centre
of which is inserted a brass tube for the suspension of the
needle by a cocoon filament. The needle is the double
astatic one of Nobili, each part being about eleven inches
long, one fourth wide, and one fortieth in thickness. The
lower part plays within the coil and the upper one above it,

3 C2

380 Prof. Locke on a ?icw Tkermoscopic Galvanometer,

and the thin white dial placed upon it, thus performing the
office of a conspicuous index underneath the glass*.

I have not yet made any very extensive experiments with
this instrument, being only just now prepared to do so. It is
very sensible to a single pair of thermo-electric metals, to the
action of which it seems peculiarly adapted ; but the efficiency
of such metals is increased by a repetition of the pairs, as in
the thermo-pile of M. Melloni, especially if they be massive in
proportion to the coil itself. With a battery of five pairs of
bismuth and antimony, the needle was sensibly moved by the
radiation from a person at the distance of 12 feet, without a
reflector, the air being at the temperature of 72°.

In a recent interview with M. Melloni, to whose politeness
I am much indebted, he expressed his opinion that with a
thermo-pile massive in proportion to the coil, my galvano-
meter might be made to exhibit his thermo-experiments ad-
vantageously to a large class. Some idea may be formed of
its fitness for this purpose from the result of a single trial on
" transmission." The heat from a small lamp with a reflector,
at the distance of five feet, passed through a plate of alum,
and falling on a battery or pile of five pairs of bismuth and
antimony deflected the needle only a fraction of one degree,
but on substituting a similar plate of common salt, the same
heat produced, by impulse, an immediate deflection of 33 de-
grees.

Although- the instrument is finely adapted by its size for
the purpose for which it was intended, class illustration, yet
from the weight of the needle and the difficulty of bringing
it to rest after it once acquires motion, it is not so suitable for
experiments of research as the Mellonian galvanometer. When
a massive thermo-pile, such as has lately been made by Messrs.
Watkins and Hill of Charing-cross, is connected with the coil
and excited by a heat of about200°,the needle being withdrawn
a distinct spark is obtained on interrupting the circuit; in
producing this effect it is less efficient however than the rib-
boncoil of Prof. Henry. The tube for suspension, placed
over the centre of the instrument, is so constructed as to ad-
mit of being turned round by means of an index, which ex-
tends from it horizontally over the glass cover, and thus any
degree of torsion may be given to the suspending filament
or wire. A wire of any desired thickness may be easily sub-
stituted for the cocoon filament, when the instrument becomes

* This instrument has been made by Messrs. Watkins and Hill, Opticians
and Philosophical Instrument Makers, No. 5, Charing Cross.

Prof. Meyen on the Progress of Vegetable Physiology. 881

adapted to measuring the deflecting forces of the galvanic bat-
tery. By using a thick wire it was ascertained that the calori-
motor of Professor Hare having 40 plates, each 18 inches
square, acted on the needle with a force equal to 92 grains,
applied at the distance of 6 inches from the centre. In at-
tempting to force the needle by torsion into a line parallel to
the coil, where the deflecting current acts with the greatest
strength, I accidentally carried it too far and reversed its 'po-
sition^ when instantly it became reversed m polarity^ that which
had been the north pole becoming the south. This showed
how unfit is the magnetic needle to measure such a quan-
tity of electricity as was then flowing through the massive
conductor. The instrument is well adapted to show to a class
the experiments upon radiant heat with Pictet's conjugate
reflectors, in which the differential or air thermometer affords,
to spectators at a distance, but an unsatisfactory indication.
For this purpose the electrical element necessary is merely
a disk of bismuth as large as a shilling, soldered to a corre-
sponding one of copper, blackened, and erected in the focus
of the reflector, while conductors pass from each disk to the
poles of the galvanometer. With this arrangement the heat
of a non-luminous ball at the distance of 12 feet will impel
the needle near 180°, and if the connexions and reversals are
properly made will keep it in a continued revolution.

I have thus given you a brief sketch of an instrument which
seems to supply a desideratum on the lecture-table, when the
common thermometer is too small to afford to a class that
direct and full satisfaction which, in a subject so important as
that of heat, is very desirable to every professor. I have not
so far attempted to use it extensively as an instrument of re-
search, yet it shows evidently the importance of massiveness
in conductors for feeble currents, such as those produced by
thermo-combinations; nor am I certain that I have arrived
at a maximum in this particular, for so far as I have proceeded
in using thicker conductors for the coil the deflecting effects
have been increased. I am, &c.

London, Aug. 30, 1837- JoHN LoCKE.

XLVIII. A Report of the Progress of Vegetable Physiology
during the Year 1836. -By J. Meyen, Professor of Botany
in the University of Berlin.*

IT is delightful to see that during the past year not only have
the works published in the province of botany been in-

* From Wiegmanu's Arch'm fur Naturgeschichtc, 1837, Part 3. Trans-
lated by Mr. Win. Francis.

382 Prof. Meyen's Report of the Progress of

creased in number, but the results of the labours recorded in
them continue to become from year to year greater and more
important. Systematic botany has received in the year which
is past numerous and valuable contributions, for a whole series
of most important works have appeared, not only on Phanero-
gamia, but also on Cryptogamia ; vegetable physiology, also,
has been enriched by a great amount of new data, and more
correct views have been diffused in numerous publications upon
many subjects, respecting which less accurate notions had
heretofore been entertained. Nay, the number of works which
appeared last year on subjects of physiological botany is so
great that it is impossible in the small space allowed us to go
fully into their contents, and it is more especially difficult to
accomplish this with respect to the rich contents of some of
the manuals which have appeared.

Several subjects of vegetable physiology which have been
very fully treated of in former reports must also be now again
noticed with greater minuteness : this perhaps might seem
superfluous, but the object aimed at by the writer in these
elaborate reports is to produce an unity in the views and an
accordance in the observations and doctrines relative to the
structure and functions of vegetables ; so that this science may
in the end become worthy to take its place by the side of ani-
mal physiology.

Great is the loss which the circle of botanists has sustained
during the year which has terminated : Schrank, Persoon,
Jussieu, and Schrader are no longer among them. Their la-
bours are known, and will long impart lustre to the history of
our science.

Since the first publication of this work ( Wiegmann's Archiv)
several yearly reports have appeared in Germany and in
France, the contents of which more or less resemble ours.
From the geographical position of Sweden, Wickstrom's year's
report on the progress of botany must always reach us very
late, and can never be so complete as if it had been prepared
in the interior of the Continent; in order to remedy this de-
fect Beilschmied has undertaken to translate those reports into
German, and at the same time to enrich them with the most
recent literature in which they are deficient. Thus last year
we received Wickstrom's report for 1834?*. A second volume
of the Archives des Decouvertes et Inventions nouvelles faites
dans les Sciences, les Arts et les Manufactures tant en France
que dans les Pays th -angers pendant Vannee 1835f has ap-

* Translated with additions and index by C. T. Beilschmied. Breslau,
1836.
t Paris, 1836, 8vo. (An extremely poor piece of manufacture. — Wiegm.)

Vegetable Physiology for the Year 1836. 383

pearecl; and Valentin of Berne* has given a critical view of
the results of the principal physiological labours belonging to
the year 1835; there is no want of competition, therefore, in
works of this class, and it is only to be hoped that no one
will go so far as to make up reports out of year's reports. The
author of the present report designs to continue his labour in
future years, and, circumstances permitting, will extend it to
systematical botany also.

Convenient as it is to science that most of the learned so-
cieties now publish more or less copious notices of the labours
of their members, it must still be remarked that short reports
on the contents of several memoirs, read at the meetings of
these societies, often appear in print, until at last, too fre-
quently after a very long interval, the entire memoirs are
published. Since however these short reports often contain
but very incomplete statements, we have in many cases
thought it necessary to wait the appearance of the original
paper itself.

On the Symmetry, Arrangement, and Characteristics of the
Nature of Plants,

The new edition of Link's Elementa Philosophise Botanica?,
which appeared last year, begins with the remark that natural
bodies, when in a perfect state, possess a more or less sym-
metrical figure. In p. 30 he adduces proof that the entire
plant or its parts are symmetrical, yet differing a little from
exact symmetry. The plant is a compound organic body ;
each individual part is almost quite symmetrical, its combina-
tion however often not so, for many exterior circumstances
hinder or accelerate the origin and growth of branches. A
variation from the symmetrical form often takes place when
superincumbent parts appear to retard complete develop-
ment.

A small tract by Mohlf treats more copiously on the sym-
metry of vegetables. It is there shown that most organs of
plants tend more or less evidently to symmetrical formation.
The concentric, symmetrical, and the diaphorical mode of
formation is in the first place distinguished, and then specially
exemplified in a great number of plants. The structure of
the lower order of plants is conceived extremely well, and
the author observes that a correct notion of those plants in
which stem and leaf are separated, can only be attained by a

• Vide Valentin's Report . fur Anat. und Physiol., &c. Berlin, 1837,
vol.i. p. 1-77.

f On the Symmetry of Plants (an Inaugural Dissertation). Tubingen,
1836, 8vo.

384* Prof. Meyen's Report of the Progress of

comparison of them with the formation of the thallus in the
lower plants. " We have seen," says he, p. 38, t* according to
what has been said, in the organs of vegetation a constant pro-
gression from the symmetrical to the concentric formation ; not
however a fixed progression, but one interrupted by fluctuations.
The pure symmetrical formation in the lower order of plants
raised itself to the concentric on the stems of the Jungermannice
and Lycopodice ; this however did not yet appear openly, but
still showed a considerableaffinity tothesymmetricalformation.
In the Phanerogamia a weak tendency to the symmetrical for-
mation is yet often evident in the stem ; on the contrary, how-
ever, in general the most determined concentric organization
shows itself; while in the leaves the symmetrical formation
takes place in a manner not less remarkable than in the thal-
lus of the Cryptogamia. In the branches we often observed a
return to the symmetrical formation, while in the more highly
developed leaf-forms many phaenomena pointed to the ten-
dency of the petiole of the leaf to raise itself to a concentric
formation. We observed in the leaved stems and in the pin-
nate leaves the symmetry showing itself in a double form :
first, in a narrow circle, in the corresponding formation of both
side-halves of the individual leaflet; and secondly, in a wider
circle, in the symmetrical formation of the two opposite leaf-
lines sacrificing the symmetry of each individual leaflet."

In flowers it rarely occurs that they are not separated by
a perpendicular section into two equal halves; and the general
rule is that all terminal flowers are regular ; that on the con-
trary irregular flowers are allotted to such inflorescences as
are not terminal. According to this the symmetrical formation
of the flowers stands in connection with their position.

Fries* has endeavoured to solve the question, which vege-
tables might be regarded as the most perfect, in a very in-
genious manner. He first shows how the views of earlier
botanists on this subject were untenable; he refutes most ad-
mirably De Candolle's view, according to which the Ranun-
culacecB were the most perfect plants; for perfection in vege-
tables does not consist in the more perfect development of
any individual organ, but in the harmonious development of all
the organs collectively into a typical whole. Fries enumerates
the following among the criteria of the perfection of a vege-
table :

1. The greater number of degrees of metamorphosis a
plant has to pass through, before the fruit is developed, the

* Essay towards a new answer to the question : Which vegetables are
the most perfect? Transl. from the Swedish by Hornschuch. Flora,
1836, p. 1—16.

Vegetable Physiology for the Year 1836. 385

more perfect it is. 2. The more complete the metamorphosis
the more perfect is the vegetable. 3. The most perfect vege-
tables have also the most regular and symmetrical formation
of the flower. 4. Those are the most perfect which not only
possess all organs, but have these also combined in the most
perfect harmony. 5. The greater stress nature has laid on
the development of the seed, the more perfect is the plant.
6. Those vegetables are the most perfect which express in the
purest manner by structure, form, numeral relations, and vital
manifestations the type of their section. And, 7. since the
typical form is the result of the most general relations, it fol-
lows from thence that the most perfect groups must be the
most numerous and the greatest.

According to these fundamental positions, which in general
are to be admitted, Fries pronounces the Composites to be the
most fully developed plants.

We have received some interesting observations on the
generation of some of the lower Algte, which continue to bring
nearer to a decision the great question, whether the Bacil-
larice, and those beings nearly related to them, are to be class-
ed under vegetables or animals. Mohl * first made known
some observations on Conferva glomerata, according to which
an increase of the members of this plant takes place by sepa-
ration. The branches of this vegetable originate constantly
on the end of the upper side of a member of the Conferva, and
in such a manner that no communication takes place between
the cells from which the branches originate and the inferior
member of the branch, but both members are entirely sepa-
rated by a septum. However, observations on branches just
beginning to shoot show that at first this septum is wanting,
and that there is present only a hook-like protuberance of the
member, which grows in a cylindrical sac of about the com-
mon length of the members. A contraction then takes place,
and appears in the form of a circular septum, pierced in the
centre, which is gradually developed, till at last the connection
between the cell of the branch and that of the stem is com-
pletely interrupted; and thus two cells entirely separated from
each other have originated from the cell of the branch. The
newly originated cell increases in size and again divides itself,
&c. In consequence of this observation, Mohl supposes that
a similar mode of increase takes place also in the genera
Scytonema and Oscillatoria ; and in this we almost en-
tirely agree with him. The same occurs also in the Rivu-

• On the Increase of the Cells of Plants by Separation. Tubingen, 1835.
(Published towards the end of 1836.)

Third Series. Vol.11. No. 68. Oct. 1837. 3D

386 Prof. Meyen's Report of the Progress of

larice, although in this case the separation does not take place
at the point of the sporangia, which however, as will be im-
mediately shown, occurs also in Confervas. From various phte-
nomena it seemed probable to Mohl that in the several species
also of the genus Spirogyra, Link, (Zygnema, Ag.), the single
cells possess the property of dividing themselves in their centre
by a septum. This supposition I can fully confirm ; for
experiments made on Spirogyra when budding (which since
Vaucher's* observations it appears no one hail repeated,)
have shown it in a most evident manner. At the commence-
ment in this case it is always the last member remaining in
the burst capsule, which increases considerably in length, and
divides itself by a new septum into two cells, upon which the
inferior cell lengthens, &c. Soon after some of these new
cells lengthen and divide again.

These data, viz. the increase of the cells in microscopical
plants by separation, are of great importance, and have hitherto
been but rarely mentioned, and never with so much certainty.
Carusf formerly observed how the ends in Achyla protifera
Nees, separated by an apparent cellular septum from the
other parts of the sac; Carus in the same memoir has also
mentioned several observations on thegradual contraction down
to the complete separation. The origin of the fruit of the
Vancheria by constriction was also known ; hitherto however
no general conclusions on the growth of these plants by sim-
ple separation of the cells had been mentioned till Dumortier
discovered a similar increase at the terminal cells of Con-
ferva aurea%. As soon as the terminal cell of this Conferva
had become considerably longer than the preceding members,
a septum formed in its interior; this observation is quite
similar to that of Mohl on Conferva glomerata. A similar mode
of increase, viz. that by forming septa, was also observed by
Morren § in the Closterice, which this accurate naturalist is
completely justified, by his very convincing reasons, in classing
amongst vegetables, on which subject however we shall by
and by have more to say.

It would now be of the greatest importance, if the datum,
first confirmed by Dumortier, that cells can increase by a
formation of septa, could also be demonstrated in the more per-
fect plants; this has been accomplished with tolerable certainty

* Hist, des Conferves. PI. 4, 5 et 6.
t Nova Act. Acad. C. Nat. Cur., t. xi. p. 503.

X Recherches sur la Structure comparee et le Developpement des Anhnaux
ctdes Vegitaux. Bruxelles, 1832, p. 10.

§ Sur les Closth'ies, Ann. des Scienc. Nat., vol. i. p. 274.

Vegetable Physiulogy for the Year 1836. 387

by Mirbel's beautiful observations on the formation of the
pollen in the Cucurbitacece. I myself have often thought I saw
in the formation of the glafidulce capitatcc of several plants the
origin of septa in the cells ; the peculiarly formed hairs on the
internal surface of the sacs in the genus Ulricularia also ap-
pear to originate only by contraction, excrescence, and sepa-
ration. Nay, even such a formation of more or less complete
septa is evident in the diachymous cells of the leaves of Pinus
silvestris; they may be seen in diagonal sections as runners
from the internal side of the cellular septum; but a complete
division of these cells is in truth not to be perceived.

An increase of vegetable cells by separation has been
already proved in a direct manner; and therefore those di-
stinctive characters which Ehrenberg* established between
animals and vegetables are by no means so conclusive, but
might on the contrary be used to prove what Ehrenberg en-
deavours to refute. Ehrenberg considers an increase by di-
vision as a character which belongs to numerous beings
plainly evincing themselves to be animals, and which is to-
tally wanting in plants, since the latter always grow by in-
creasing in length and the formation of buds ; and that on that
account the Bacillarice are not plants, but must be classed with
animals. As it has now been proved that the division of cells
takes place exactly in the same manner in well-defined plants
as in the Bacillarice, and as it can be shown that the separa-
tion in the increase of Infusoria and other lower animals is
very different from this separation of vegetable cells, such a
separation by septa might even furnish a character to di-
stinguish vegetables from animals.

Mohlf observes that the character mentioned by Ehren-
berg, viz. the power of separation in animals, the want of it in
plants, suffers the fate of various other distinctive characters
which have been started separately : in general they are right, but
in special and doubtful cases they are not to be depended on.
Mohl here refers to his observation on the separation of the
conferval sacs, of which we have already spoken. Mohl also
confesses that after many years' observation he still remains
quite in doubt as to the place which the Bacillaria; should
occupy, that however their increasing by separation does not
justify us in classing them as animals.

* Memoir read before the Academy of Berlin 25th of April. Ulnsiitut,
p. 195. Also Scientific Memoirs, vol.i. p. 405.

f On a Character for distinguishing Animals and Plants proposed by
Ehrenberg. Flora, 1836, vol. ii. p. 491 -494.

3 D 2

388 Prof. Meyen's Report of the Progress of

I may also mention that Link*, Ungerf, and Morren J
have of late remarked that these doubtful creatures which are
known under the name of Bacillarice ought to be arranged
with vegetables ; according to this there would remain no other
botanist, with the exception of Corda, that had paid any con-
siderable attention to vegetable anatomy who did not con-
sider the Bacillarice to be plants.

From this we may judge of the contradictions on this sub-
ject, which are found in the reports edited by Wiegmann
and myself on the progress of zoology and physiological bo-
tany for the year 1835§; as these creatures are at times men-
tioned as plants, at times as animals, and indeed under quite
different denominations ||.

Morren, in the above-mentioned highly important memoir
on the Closteria?9 has very fully treated the question whether
they should be arranged with animals or vegetables ; he suc-
ceeded, by employing very high magnifying powers, in show-
ing that those red and very moveable little points discovered
by Ehrenberg at the ends of these beings were nothing else
than minute vesicles which afterwards change into new indi-
viduals. It was these moveable and as it were oscillating
points which were considered as organs of motion, and ap-
peared to justify the placing of the Closterice among animals,
which however at present, after Morren's discovery, falls to
the ground. Besides the occurrence of these self-moving pi o-
pagula in the interior of the Closteria?, Morren has observed
a formation of fruit by conjugation quite similar to the mode
of formation of the fruit in the Cotijugatce% ; and besides this,
there also takes place an increase of the Closterice by separa-
tion.

The siliceous envelope which surrounds the Closterice as well
as all other Bacillarice is regarded by Morren as a formation
analogous to the so-called cuticula of plants, a fact which is ca-
pable of confirmation only in certain relations; for in the per-
fect plants this fine plate of silica lies in the substance of the

* Philos. Bot. Edit, alt., p. 400.

f Vide his treatise on Algce in Endlicher's Genera Plantarum.

X Sur les Closteries, I. c. § Wiegmann's Archiv.

|| I am sorry to say that these contradictions must also occur in this year's
report; as I do not think Ehrenberg's view as to the animal nature of the
BacillaricE weakened by the reasons here stated. — Wiegmann.

1 The same observation has been already made by Corda and noticed by
me in the report for the preceding year (1836, vol. ii. p. 186). It had al-
ready been mentioned by Ehrenberg also in 1834. (Beitr. z. Kenntn. gr.
Organis. in der Richtg. d. hi. Raumes, p. 95.) — Wiegmann.

Vegetable Physiology for the Year 183b*. 389

cuticulay and is only separated from this by the destruction of the
organic parts. Besides this siliceous envelope Morren supposes
the existence of two other distinct membranes, which form the
cuticle of the Closteria? and inclose the green substance ; he
however remarks that they only become evident upon the me-
tamorphosis of the plant. I consider the inner pellicle to be the
analogue of the inner envelope which is formed in the members
of Confervae when their spores are ripened, or they begin
to increase in any other manner, as tor instance by excre-
scence and separation. Morren thinks it possible to explain
the motion of the Closterice by the action of opposite electri-
cities. The author also gives a very complete description,
accompanied with drawings, of the very manifold forms which
the Closterice exhibit at different periods ; and by this he shows
how at least six of the new species of the genus Closterium, de-
scribed by Ehrenberg, belong to one and the same species.

De Brebisson* also made observations on the enigmatical
Diatomece in order to decide the question whether they should
be classed with animals or vegetables. On burning a great
number of Fragilaria pectinalis an animal smell was noticed.
Such a smell would however be a very indefinite character,
for various other Algae produce a similar odour on their being
burnt to a coal. After the burning of the Fragilaria pecli-
nalis, and various other beings of the same kind, Brebisson
found siliceous envelopes surrounding them in a very per-
fect state, and precisely similar to those exhibited by[the fossil
Diatomea? discovered by C. Fischer in the peat- bog near Franz-
ensbad, and which led to those beautiful observations that
Ehrenberg made known on this subject in the course of last
yearf. The results of those latter observations belong pro-
perly to geognosy ; but we must add this one remark, that
under the fossil Infusoria hitherto discovered, only those beings
are to be understood which botanists, as has been previously
shown, receive as plants. The occurrence in a fossil state of
these minute microscopical plants is caused by the hard sili-
ceous envelope, which resists all destroying influences. Kiit-
zing's discovery that the envelope of the Bacillaricc consists
oi silica, which was mentioned in our first year's report, has
by this circumstance been rendered more important. If we
observe the same minute plants in the living state, it often
happens that amongst them some dead ones occur, which ex-

* Observations sur les Diatomees. — V Institut de 1836, p. 378. — Ann. des
Scienc. Nat. 1836, ii. p. 248.

f Vide On Fossil Infusoria, Wiegmann's Jrchiv, 1836, p. 333. A trans-
lation of Ehrenberg's two papers on this subject is given entire, and with
engravings, in the Scientific Memoirs, vol. i. p. 400. — W. F.

390 Dr. Dal ton on the Theory of the Winds.

hibit that perfectly transparent and colourless siliceous en-
velope; it is therefore proved by this circumstance that a great
mass of such siliceous envelopes might also be produced by
the decomposition of the -plants, or in the moist waj/ ; and also
that the mountain masses, which consist more or less of such si-
liceous envelopes, might not always be regarded as being pro-
duced by the action of heat at the bottom of the sea*. Bre-
bisson tries to bring the Diatomecc into two divisions, viz. the
proper Diatomece, which exhibit a siliceous envelope, and the
Desmidicc, which are without a siliceous coating and entirely
reduceable to carbon. In the more perfect plants, the epi-
dermis of which is penetrated by a siliceous envelope, it would
at least be improper to make such divisions ; in this case, how-
ever, they may be of some use.

In a recent memoir Mohlf has again declared himself
against the animal nature of the Bacillarice. M I admit," says
he, " that the doubt which was raised respecting their vege-
table nature is not yet removed ; their animal nature however
has been as little proved, and we find evident transitions from
them to vegetables, &c.

[To be continued.]

XL1X. Notice relative to the Theory of the Winds. By John
Dalton, D.C.L., F.R.S.

To Richard Taylor, Esq.

Dear Friend, Manchester, Sept. 5th, 1837-

1 PUBLISHED a theory of the Trade Winds, &c, as Mr.
■*■ Dove has published:):, — it was forty-four years ago, as may
be seen in my Meteorology, 1793 and 1834<. It was first
published by G. Hadley, Esq., in 1735, as I afterwards learnt.
It is astonishing to find how the true theory should have stood
out so long. John Dalton.

L. Proceedings of Learned Societies.

GEOLOGICAL SOCIETY.

A LETTER addressed to C.Lyell,Esq. was then read from Dr. Mc
Cleland,who has been associated with Mr.Griffith in the scientific
deputation sent under Dr. Wallich into Upper Assam to investigate
the natural history of the country where the tea-plant is found growing

* Ehrenberg's opinion is that these masses owe their origin to the action
of volcanic heat on the bottom of the sea. Vide Scientific Memoirs, vol. i.
p. 400.— W. F.

t On the Symmetry of Plants. Tubingen, 1836, in December. (Published
as an Inaugural Dissertation.)

J See our last and present Numbers.

Geological Society. 39 1

wild. The deputation left Calcutta in the end of August, and reached
the Kossia Mountains early in October. In crossing the Delta of the
Ganges and Bramaputra (Burrampooter), a high tract of land, two or
three hundred feet above the level of the plain, was observed (but not ex-
amined) near Dacca. Between this and the Kossia Mountains, distant
sixty miles, the old channel of the latter river extends, so that the
above high land is situated between the channels of the two great rivers.
The country is generally composed of silt, but at Mymensing (where
the navigation is most obstructed), the Bramaputra crosses abed of yel-
low clay containing ferruginous and calcareous (the kun/car of India)
concretions. The author thinks this bed of clay extends from the
above high land to the foot of the Kossia Mountains, or the extreme
point of the portion called the Garrow Hills, where the late Mr. Scott
found the fossil remains of animals. The partially inundated plain at
the foot of these mountains is interspersed throughout with small
rounded hills, which reposing on the above-mentioned yellow clay
are themselves composed of various layers of sands, clays, gravels,
and boulders, even at the greatest heights. These appear to be the
remains of a talus of great extent, which had covered the foot of these
mountains and been swept away by the Soorma and other great rivers
falling from them.

The foot of the mountains is composed of a rock in which Num-
mulites are imbedded in a compact calcareous basis. Sandstones
seemed to rest upon this, but the relative position of the two rocks
could not be clearly ascertained from the dense vegetation and the
short time available for the examination.

On ascending to Cherraponji, a sanatory station established at
an ascertained height of above 5000 feet, the limestone was soon
lost sight of; but great masses of sandstones presented themselves,
which had been rent and the fissures filled up with boulders and gra-
vel. If the mountain acclivity be supposed to be divided into three
stages, the first forms a steep slope covered with deep soil and vege-
tation ; the second is precipitous and more or less naked ; and the
third is composed of sloping ridges terminating in mountain and table
lands from 5000, to near 6000 feet high.

At the top of the first stage, or at about fifteen hundred feet above
the sea level, the author discovered a well-defined marine beach, con-
taining shells and other marine exuviae about two feet deep, and
reposing upon sandstone and covered with soil. The shells consist
of Pectens, Cardia, Ostrea?, Terebratulse, and Melaniae, mineralized
by a fine yellow sandy matter, and united together by a brown indu-
rated clay. Between the curved slaty layers of animal matter and
shells, as well as in nests, loose sand is found. The whole presented
the form of shingles caused on a beach subject to tides. In the course
of an hour several hundreds were, and with more time many thousands
might have been obtained. These shells were compared with a col-
lection of about one hundred and fifty species from the Bay of Bengal
and the estuaries of the great rivers, but not one was found to cor-
respond; nor with those found by the late Dr. Gerrard in the second-
ary strata on the north of the Himalaya; but a small collection of

392 Geological Society.

about one hundred species from the Paris basin were at once recog-
nised by the author as familiar objects, from his acquaintance with
those from Kossiaand Cherraponji : these consisted of about an equal
number of species, and on being submitted to systematic comparison
about twenty species were found to be identical in the two collections.

On crossing this deposit, the rock composing the superficial strata
of sandstone forming the precipices of the second part of the ascent,
was found to contain the impressions of shells and other organic re-
mains, which the author believes to be ramose Alcyonia ; these
continued to appear all the way up to Cherraponji, where they oc-
curred in the greatest numbers.

On this sandstonereposesadepositof compact !imestone,from which
twenty-seven species of shells were extracted, as species of Trochites,
Cerithia, and of Modiola of Lamarck, with Piliolus plicatus of Sow-
erbv. On this formation reposes a bed of coal to the depth of above
twenty or thirty feet, in which was found an exogenous plant. On
descending towards the plain from a point five or six miles west of
Cherraponji, and one or two miles below the village of Mumloo, an
elongation of the same fossil beds and sea beach was met with at
about the same elevation. The shells and characteristic remains, with
six species of Medusae, were found imbedded in a red sandstone, or
rather indurated sand, immediately beneath the soil.

On crossing the mountains towards the centre of the group, the
sandstone, on which the limestone and coal rest at Cherraponji, was
found for fifteen or eighteen miles, forming in horizontal strata lofty
undulating lands, with little variation except in ravines and the banks
of streams. Beyond the above distance the strata displayed marks
of confusion, and in the first deep river valley, a mass of greenstone
was found with the adjoining sandstone tilted up in highly inclined
tabular masses, formed of quartzose pebbles imbedded in felspar.
This form continued to the second deep valley, where the greenstone
was again met with, and the adjoining sandstone compact, glossy,
and columnar.

Leaving this (the Boga Pany) and ascending the opposite ac-
clivity, all traces of the earthy sandstone are lost, and the centre of
the mountains from Mufling to the highest ridges is composed of
syenite. Granular quartz, slaty and in vertical strata, is found in con-
tact with this, and interposed between it and the common sandstones ;
displaying progressive changes from one to the other. The northern
side of the mountains from Muflong into Assam is composed of gra-
nular foliated felspar, penetrated by quartzose veins, and more irre-
gularly with beds of mica. Extensive beds of syenite and central
nuclei of granite are found as far as the Valley of Lower Assam, which
here is about thirty miles broad, and bounded on the north by the
Bustan Mountains. Groups of rocky hills extend from the Kossia
and Garrow Mountains across the valley, threatening as it were to in-
terrupt the waters of the Bramaputra and convert the interior of the
valley into a lake. These called the Meeker Hills, are composed of
insulated rocky protrusions of metamorphosed gneiss, in some in-
stances syenitic, in others as a sandstone whose base is earthy felspar

Geological Society* 393

containing crystals of the same mineral, and in others as hornblende
slate j all, and especially the second, with veins and beds of quartz
projecting upwards, the veins often radiating irregularly from the beds.
Along the veins a laminated structure is produced in the rock -, this
structure follows the course of the vein, and disappears as you recede
from one vein, re-appearing again as you approach another.

These, as well as many other objects of geological interest, could
only be cursorily observed from the necessity of accompanying the
expedition. Hot and salt springs, — from the latter the natives derive
a muriate of soda, — as well as fossil bones, as first discovered by the
late Mr. Scott, present themselves along the base of the mountains.

The author also collected about one hundred and sixty species of
the animals, chiefly birds, from the forests of Assam, which have been
forwarded to the India House, as well as one hundred and twenty
species of the fishes of the Bramaputra in Upper Assam ; many of
which are identical with Hamilton's Gangetic species, but several are
new; regarding the habits and peculiarities of which the author states
having collected considerable details.

On the remains of a fossil Monkey from the tertiary strata of the
Sewalik Hills in the north of Hindoostan ; by Captain P. T. Cautley,
F.G.S., Bengal Artillery, and H. Falconer, M.D., Bengal Medical
Service.

The authors commence their paper with some general observations
on the differences in habit in different animals, which prevent the
remains of some being so frequently preserved as those of others
in a fossil state, and they adduce as instances birds and quadrumanous
animals. So speedily are the remains of these carried away by the
hyaena, the chacal and wolf, the scavengers of torrid regions, that in
India, the traces of casualties are so seldom seen,- — even where mon-
keys occupy in large societies the groves of mango trees round villages,
— that the simple Hindoo believes they bury their dead by night.

The authors since engaged in the examination of the Sewalik fos-
sils, were early led to anticipate the finding of some quadrumanous
animals, and several months ago obtained an astragalus of the right
hind leg, which they minutely describe, and compare with that of the
recent Semnopithecus Entellus ; which, though certainly belonging
to a distinct species, it closely resembles both in size and general
form, as is exemplified in the specimen sent with the fossil astragalus.
This was completely mineralized, having a sp. gr. of about 28 and
appearing to be impregnated with hydrate of iron. Although only a
solitary bone of the foot, the relations of structure are so fixed that
the identity of the fossil is as certain as if the entire skeleton had been
found. But the authors deferred making the announcement, in the
hopes of soon finding specimens of the cranium and teeth j these have
been discovered by Messrs. Baker and Durand of the Bengal Engi-
neers, who have obtained a considerable portion of the face, and the
whole series of molars of one side of a quadrumanous animal, be-
longing to a much larger species than theirs.

In the debris or different beds of the formation which yielded the
quadrumanous fossil astragalus, the authors have also discovered Ano-

Third Series. Vol. 11. No. C8. Oct. 1837. 3 E

39 i Zoological Society.

plotherium Sivalense, F. and C, with Crocodilus biporcatus and C*
(Lepforhyncus) gangeticus or the Magar, and Garial (Gavial), which
now inhabit the Ganges, showing that the quadrumana existed, with
a member of the oldest Pachydermatous genus of Europe and reptiles
of the present day.

The camel (Camelus Sivalensis, F. and C), antelope, and ano-
plotherium have been exhumed from the same bed. There have been
found also the elephant, mastodon, hippopotamus (H. Sivalemis and
H. dissimilis, F. and C.)» rhinoceros, hog, and horse, together with the
S'watherium giganteum, a huge ruminant, exceeding in size the largest
rhinoceros, armed with four enormous horns, divided and foli-
ated like the dicranocerine antelopes. There is also a musk deer
scarcely larger than a hare j specimens of the cat (Fells cristata,
F. and C.) and of the dog tribe ; the hyaena, bear (Ursus Sivalensis,
F. and C), and ratel, with other carnivora. Of the feathered tribe,
there are Grallse much larger than the gigantic crane of Bengal
(Ciconia Argala). Of reptiles, besides the magar and gavial, there
are other crocodiles of enormous size (C. Leptorhyncus crassidens,
F. and C.) j and of Testudinata ordinary-sized species of emys and
trionyx, with humeri and femora as well as corresponding fragments
of the bucklers of a species as large as the corresponding bones of
the Indian rhinoceros. The authors refer to the " Journal" and f* Re-
searches of the Asiatic Society of Bengal" ["the Asiatic Researches"]
for descriptions of their new species.

ZOOLOGICAL SOCIETY.
[Continued from p. 201.]

December 27th, 1836. — The remainder of M. F. Cuvier's Paper
on the Jerboas and Gerbillas was read.

M. Cuvier commences this memoir with observing that his atten-
tion has been particularly directed to the Rodentia, with a view of
arriving at a natural classification of the numerous species composing
that order, among which considerable confusion had hitherto pre-
vailed, particularly in the genera Dipus and Gerbillus, the relations
of which to other allied groups have been but very imperfectly un-
derstood by previous writers.

The species included in the genus Dipus have been formed by
M. Lichtenstein into three divisions, which are distinguished by the
absence and number of rudimentary toes upon the hind feet. In the
first section are placed those with three toes, all perfectly formed ; in
the second, those with four, one of which is rudimentary ; and in the
third, those with five, two of these being rudimentary. M. Cuvier
states that he is unacquainted with the second division of M. Lich-
tenstein, but in the examination of the species belonging to the first,
in addition to the absence of rudimentary toes, he finds they are also
distinguished from those of the third by the form of the teeth, and
the osteological characters of the head. These points of difference
he considers of sufficient importance to justify his making a distinct
genus for the Jerboas with five toes, adopting the name Allactaga,
given by Pallas to a species, as the common generic appellation.

Zoological Society. 395

** We know," observes M. Cuvier, "^that the three principal toes
of the Allactagas, as well as the three only toes of the Jerboas, are
articulated to a single metatarsal bone, and that the two rudimentary-
toes of the first genus have each their metatarsal bone ; whence it
results that the penultimate segment of the foot is composed of three
bones in the Allactagas, and of one only in the Jerboas. The incisors
of the Allactagas are simple, whilst those in the upper-jaw of the
Jerboas are divided longitudinally by a furrow. The molars of the
latter genus are complicated in form, and but little resemble those of
the former. They are four in number in the upper-jaw, and three in
the lower, but the first in the upper is a small rudimentary tooth,
which probably disappears in aged individuals."

The structure of the grinding teeth is then described in detail, and
illustrated by drawings which accompanied the paper.

" The general structure of the head of the Allactagas and Jerboas
is evidently the same, and is characterized by the large size of the
cranium, the shortness of the muzzle, and above all by the magnitude
of the suborbital foramina. The cranium of the Jerboa is distin-
guished by its great breadth posteriorly, resulting from the enormous
development of the tympanic bone, which extends beyond the occi-
pital posteriorly and laterally as far as the zygomatic arch, which
is by no means the case in the Allactagas, where all the osseous parts
of the ear are of moderate dimensions. Another differential character
between the two genera, is presented by the maxillary arch, which
circumscribes externally the suborbital foramina, and which, in the
Allactagas, may be said to be linear, and presenting a very limited
surface for the attachment of muscles. Lastly, we may note a dif-
ference in the relative development of the jaws, the lower being com-
paratively much shorter in the Allactagas than in the Jerboas"

The author then proceeds to describe a new species of Allactaga,
a native of Barbary, for which he proposes the name of A . arundinib.
Its length from the origin of the tail to the end of the muzzle, 5 inches ;
length of the tail, 5 inches and 2 or 3 lines; of the ears, 1 inch; length
of the tarsi from the heel to the extremity of the toes, 22 lines. All
the upper parts of the body are of a beautiful greyish yellow, with
yellowish sides and tail of the same colour, terminated by a tuft of a
blackish brown at its origin, and white at the extremity. The sides
of the cheek, the ventral surface of the body, and the internal limbs
are white ; large brown moustaches adorn the sides of the muzzle.
The incisors are white and entire, the ears almost naked.

M. Cuvier next proceeds to consider the characters and affinities
of the genera Gerbillus and Meriones, and enters into a critical ex-
amination of all the species referred to that group. To these he adds
another species, the habits of which he details, and describes at length
under the name of G. Burtoni. The species which he thus includes
are, 1st, G. Egyptiacus, syn. Dipus Gerbillus, Meriones quadrima-
culatus, Ehrenberg ; 2nd, Gerbillus pyramidum, syn. Dipus pyramidum
Geoff., Meriones robustus Riipp. ; 3rd, G. pygargus, syn. Meriones
Gerbillus, Riipp. ; 4th, G. Nidicus, syn. Dipus Nidicus, Hardwicke ;
5£h, G. Africanus, syn. Meriones Schlegclii Smutz., G. Afra Gray;

3 E2

396 British Association for the Advancement of Science,

6th, G. brevi-caudatus ,• 7 th, G. Otaria ; 8th, G. Burt oni. The author
enters into detailed descriptions of each of these species from original
specimens. M. Cuvier lastly considers the affinities of the Gerbillas
and Allactagas to the Gerboas, and concludes that the Gerbillas have
a much nearer affinity to the Muridce.

BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE :
MEETING AT LIVERPOOL.

Sept. 13. — Professor Graham made a communication on the sub-
ject of the Inorganic Salts, and in particular, on the function which
water discharges as an element of their composition. He had been
requested, at the meeting of the Association held in Dublin, to re-
port at some future meeting on the present state of our knowledge
of saline bodies; and his communication to the Section was under-
stood to have been made with the view of discharging the duty
which had been thus imposed on him.

The Professor developed at some length his own views respect-
ing the constitution of salts. The hydrated acids are unquestion-
ably salts, having water as base, and they correspond in a remark-
able manner with the salts having for base magnesia, oxide of zinc,
oxide of copper, or any other oxide isomorphous with magnesia.
Hence water as a base belongs to the magnesian class of oxides.
Super or acid salts have two bases, of which water is one. They are
double salts, and correspond with the double salts of the same acids
containing magnesia, oxide of copper, &c. Thus the salt called the
binoxalate of potash is really a double oxalate of water and potash,
and corresponds in constitution with the double oxalate of copper
and potash, as will be seen on comparing their formulae below :

K CC H CC H2, and

K CC Cu CC H*.

Mr. Graham's researches tend to prove that all salts are neutral
in composition, with the exception of certain specified classes. One
of these classes is the phosphates, of which there are three kinds,
containing respectively one, two, and three atoms of base to one
atom of acid, and for which the names of monobasic, bibasic, and
tribasic phosphates are proposed, in substitution for the old names
of metaphosphates, pyrophosphates, and common phosphates. In
some of the tribasic phosphates, the three atoms of base are all dif-
ferent, as in microcosmic salt, in which we have an atom of soda,
of ammonia, and of water, all united together, to one atom of phos-
phoric acid. Only one class of arseniates exists, but it is the tribasic
class ; it is likewise probable that the phosphites are all tribasic ; but
all the other classes of salts at present known, such as the sulphates,
nitrates, &c, are monobasic. In the case of those combinations
which are at present called subsalts, Mr. Graham finds that there
is really only one atom of base to one atom of acid. In the ordi-
nary neutral salts, such as nitrate of copper, we have several atoms
of water in combination with the salt, and known as water of cry-

Prof. Graham on the Constitution of Salts. 897

stallization, but which Mr. Graham distinguishes as constitutional
water. Now it appears that metallic oxides may be substituted for
this constitutional water ; and it is in this way that subsalts come to
be produced. Thus the salt called subnitrate of copper is really a
nitrate of water with three atoms oxide of copper attached to that
combination in the place of water of crystallization. The nitrate of
water, or nitric acid of specific gravity 1*42, the nitrate of copper,
and the subnitrate of copper, are all of similar constitution, and are
represented by analogous formulae, viz ,

HN 11%
Cu N W,

HNCu'.

These formulae illustrate the constitutional neutrality of salts. In
each of them we have one atom only of oxide in the relation of base
to the acid, (which is expressed by placing its symbol to the left of
the symbol of the acid ;) while in each salt we have three atoms of
oxide in another and totally different relation to the acid. Certain
salts appear to be capable of combining with anrrvdrous acids, and
then a new order of saline combinations is produced. The sulphate
of potash and chloride of potassium absorb anhydrous sulphuric
acid without decomposition, as has been proved by H. Rose. The
red chromate of potash is analogous to Rose's salts, but more per-
manent. It is not a true fo'chromate of potash, but a binary com-
bination of chromic acid with the neutral chromate of potash with-
out any water. The red chromate of potash is therefore not an ex-
ception to the law, that all salts are neutral in composition. It is
well known that all the ordinary salts of ammonia contain an atom
of water, which forms part of the base, and that they may be repre-
sented as containing the oxide of a hypothetical radical ammonium.
Mr. Graham considers water as the true base of these salts, and that
ammonia is not a base itself, but belongs to a class of bodies which
may be called basic adjuncts, which admit of being attached to the
oxide of hydrogen or to the oxides of metals, the only true bases.
Thus the sulphate of ammonia is truly the sulphate of water, with
ammonia as a basic adjunct. The sulphovinates contain sulphate of
water, with defiant gas as a basic adjunct. The nature of the con-
stitution of the combinations of dry salts with ammonia can now be
explained. In these combinations the metallic oxide is in the place
of the basic water of the ordinary ammoniacal salts. Thus, chlo-
ride of hydrogen (muriatic acid) combines with one atom of ammo-
nia; chloride of copper does the same thing, and the ammonia can-
not be expelled or separated by heat in either case. These combi-
nations are represented by analogous formulae :

NH3 H CI, and
Nff Cu CI.

Anhydrous sulphate of copper absorbs, at an elevated tempera-
ture, half an atomic proportion of ammonia, and retains it by a most
powerful affinity. It is curious that in similar circumstances oil of

398 Intelligence and Miscella?ieous Articles.

vitriol or the sulphate of water absorbs the same proportion of am-
monia, the bisulphate of ammonia being produced. The two pro-
ducts are of the same constitution. The basic adjunct, ammonia,
is attached to oxide of copper in the one case, and to oxide of hy-
drogen in the other. Both are double salts, and may be expressed
by the following formulae : —

Cu S + NH3 Cu S, and

HS + NrP H S.
It thus appears that the ordinary ammoniacal salts which contain
water, are a particular class of an extensive order of salts; as, for
the water there may be substituted oxide of copper, oxide of zinc,
nickel, cobalt, and many others. Many of these combinations are
capable of assuming an additional dose of ammonia, which, however,
is feebly retained, and is in a relation to the salt like that of water
of crystallization.

In the discussion which took place on Prof. Graham's communica-
tion, Mr. Richard Phillips gave it as his opinion, that the difference
between constitutional water and basic water arises from the well-
known law, that when one principle combines with more proportions
than one of another, the first proportion is held with a stronger af-
finity than the others. — Mr. G. Bird could not conceive how water
could be considered as a base, and inquired what view Professor
Graham would take of the function of the atom of water in oil of
vitriol and in caustic potash. — Dr. Faraday expressed his satisfac-
tion that such a variety of opinions should be advanced, and even he
maintainable by powerful arguments, upon so interesting a subject;
for, from this collision of opinion, it was most likely that the truth
would ultimately be struck out. He also cautioned chemists against
considering electrical relations as affording, in every instance, con-
clusive proofs of what is abase and what is an acid. — Prof. Johnston
concurred in the observation of Dr. Faraday, and professed that he
had a very strong leaning to the theoretical views in reference to
the constitution of salts which had been just propounded by Pro-
fessor Graham. — Dr. Kane made some remarks on the same sub-
ject, objecting to some of Professor Graham's statements. To
these Professor Graham briefly replied, and the discussion closed. —
Athenteum, Sept. 23, p. 695.

LI. Intelligence and Miscellaneous Articles.

ON THE THERMO-ELECTRIC SPARK, AS OBTAINED FROM A
SINGLE PAIR OF METALLIC ELEMENTS. BY MR. FRANCIS
WATKINS.

To the Editors of the Philosophical Magazine and Journal.
Gentlemen,

I HOPE you will allow me to make known in your forthcoming
publication a fact in thermo-electricity which I have ob-
served since my last communication to you, and which I believe has
not been noticed in print in this or any other country.

Intelligence and Miscellaneous Articles. 399

With a pair of metallic elements, consisting of one bismuth and
one antimony, weighing each five grains and measuring 0*5 of an
inch long and 0 12 diameter, when their extremities were unequally
heated, I have obtained, with a Henry's flat ribbon coil, a very per-
ceptible and brilliant spark.

I have had the pleasure of showing the experiment to MM. De
la Rive, Plateau, and Netschayef, and I need not add that these
distinguished philosophers were much delighted on seeing the ther-
mo-electrical light developed by a single pair of metallic elements.

Now I have pen in hand permit me to state that with thermo-piles
I actuate most of the apparatus usually employed for illustrating
electro-magnetic phenomena, so that the public teacher may now
show by the same apparatus the several rotations, &c. with thermo-
electricity, as he does with voltaic electricity.

I remain, Gentlemen, &c. Francis Watkins.

5, Charing Cross.

ON THE ARTIFICIAL PREPARATION OF FORMIC ACID.

Prof. J. B. Emmet of the University of Virginia makes the fol-
lowing observations respecting, and proposes the annexed methods
of preparing formic acid :

One part of tartaric acid (or sugar), one and a half of peroxide
of manganese, one and a half of sulphuric acid, diluted with about
two and a half parts of water, when well mixed and subjected to
distillation, will furnish the formic acid according to Dcebereiner's
process. In order to diminish the inconvenience arising from the
frothing of this mixture, and which is exceedingly great, it is directed
to add only half the amount of dilute acid at first, and to make use
of a retort having five or six times the bulk of the matter to be put
into it.

The explanation given by Dcebereiner and other chemists, assigns
to the peroxide of manganese an agency absolutely necessary for suc-
cess, viz. that, while it parts with a portion of its own oxygen and
combines, as the protoxide, with sulphuric acid, it is enabled by the
oxygen thus detached, to convert the tartaric acid (or sugar) into
the formic and carbonic acids.

The whole of this explanation is, however, incorrect, as will ap-
pear from the following results of my inquiry.

1. The presence of peroxide of manganese, (or any other per-
oxide,) is not only unnecessary, but positively injurious and produc-
tive of much inconvenience, his positively injurious in consequence
of the power which all peroxides have of decomposing formic acid,
and productive of inconvenience in consequence of the vast amount
of carbonic acid which it produces with the formic acid and the car-
bon deposited during the operation. The latter is, in fact, the cause
of the excessive frothing.

2. Sulphuric acid is not essential. The formic acid was prepared
by phosphoric acid as well as by the chloride of tin ; and no doubt
all other substances, capable of converting alcohol into aether, may
be shown to possess the same power. In no case does sulphuric acid,

400 Intelligence and Miscellaneous Articles,

phosphoric acid, or chloride of tin undergo any decomposition, un-
less incidentally.

3. The formic acid may be procured from almost every kind of
vegetable matter that is capable of being promptly blackened by
contact with strong sulphuric acid. It rarely appears previous to
the carbonization*, and only when the sulphuric acid possesses a
powerful affinity for water.

It would appear, from these particulars, that the process for ob-
taining formic acid artificially is analogous to those operations for
converting cotton, ligneous matter, &c, into gum — gum or starch
into sugar, and alcohol into aether or olefiant gas, as far as regards the
integrity of the sulphuric acid j but, in another respect, namely, the
abundant deposition of carbon, previous to the escape of the formic
acid, the action more resembles what occurs when alcohol changes
at once into carbon and olefiant gas. The resemblance is still closer,
if, as I suppose to be the case, the agency of the sulphuric acid con-
sists in removing water, or its elements, from the organic substances,
which yield the formic acid when under its influence. I have men-
tioned that the phosphoric acid may be substituted for the sulphuric.
In the experiment to determine this, the absence of the latter acid
was accurately proved by muriate of baryta; starch was employed,
and the phosphoric acid had the consistency of syrup. But although
important for the investigation, as a fact, the substitution really can-
not, in practice, be made with advantage, because the phosphoric
acid has not the same degree of affinity for water, and before the
essential action occurs, (well indicated by the separation of carbon,)
the organic matter becomes decomposed, more or less, from simple
exposure to heat, which thus imparts to the formic acid an unplea-
sant empyreumatic taste. The same remark applies to the chloride
of tin.

There is little doubt, therefore, that, under the influence of strong
sulphuric acid, gum, sugar, starch, lignin, &c, bear the same gene-
ral relation to formic acid, and the latter to oxide of carbon, that
alcohol does to hydric cether, and the latter to olefiant gas or sethe-
rine. Thus,

„.. . ., \ Water from {ilcoholTfamh*es^dr¥«l><f-
sulphuric acid, I [ Sugar, <yc. „ formic acid,

by subtracting ] Water from S^Etker, „ olefiant gas.

L [Formic Acid, „ oxide of carbon.

By a comparison of combining proportions, it will be seen that
this explanation enables us to dispose of all the elements except two
of hydrogen.

Thus, by adopting (C + O + H) as the formula for one atom of
sugar; and, supposing four atoms to be the smallest amount involved

* When the chloride or sulphate of tin is employed, perfect carbonization
does not take place, yet the formic acid is generated readily. There is no
doubt, however, that some variety [or combination] of carbon separates at
the same time. Sugar, for example, gave a large deposit of a snuff brown
colour, and resembling in its properties the ulmin of rotten wood.

Intelligence and Miscellaneous Articles. 401

in the process, we shall have (4C+4- 0 + 4H), from which subtract
H, or one atom of water, (removed by the sulphuric acid,) and we
shall have 4C + 30 + 3H, which is equivalent to one atom of for-
mic acid (2 C + 3 0-j-H) together with 2 carbon, precipitated, and
2 hydrogen, unaccounted for. Again, assuming (6 C + 5 0-\-5 H)
as the formula for one atom of starch, and subtracting 2 H, or two
atoms of water, removed by the sulphuric acid, the remainder will
be equivalent to one atom of formic acid, (2 C-f-3 O-fH) together
with 4 atoms of carbon deposited, and 2 atoms of hydrogen unac-
counted for.

During the preparation of formic acid by Dobereiner's process,
as well as by my own, in which no peroxide of manganese is em-
ployed, there is always formed, previous to the carbonization, a con-
siderable quantity of volatile oil, which, at first, might be considered
as arising from the excess of hydrogen and carbon in the process ;
but a special inquiry has convinced me that this is not the case, al-
though the oil is so abundant that it may actually be observed float-
ing in drops down the neck of the retort. When the sulphuric acid
is so far diluted as not to carbonize the mixture at the heat of boil-
ing water, little else than this spicy oil passes over by distillation;
but as soon as the matter becomes black, its formation ceases, and if
we begin at once with sulphuric acid about one half diluted, it does
not appear at all; but, instead of it, strong formic acid, without any
foreign odour, and quite colourless. This volatile oil would not be
regarded as objectionable by many, since it imparts an aroma to the
acid like that of cassia or cinnamon, and a taste somewhat similar to
that produced by hydrocyanic acid.

The process which I recommend, as having been found the most
convenient and perfect, for obtaining strong formic acid, is the fol-
lowing.

Mix together in a glass tubulated retort, equal measures of water,
oil of vitriol, and clean, but unground rye, (or cracked maize), let
them be heated to the boiling point, and, as soon as the mass has
become thoroughly blackened, add another measure of water and
distil off one measure of formic acid.

By the addition of a further quantity of water, and by fresh dis-
tillation, a weaker acid may be obtained, which will answer very well
to be added in subsequent operations. Besides being too weak, the
product of this second distillation will often contain some sulphurous
acid, which seldom appears in the first, and never is essential to the
process. It occurs in company with oxide or carbonic acid, and may
he removed by agitating, for a short time, the cold formic acid with
peroxide of lead, as recommended by Berzelius.

By employing the whole grain, when small enough, as of rye,
wheat, oats, &c., and in the great proportion here recommended,
the contents of the retort become too solid to froth up easily, so that
the medium sized vessels may be employed. Indeed, still smaller
ones may be substituted, by simply allowing water to enter through
a dropping funnel at the tubulure, in proportion as it is removed by
the distillation. — Sillimans Journal, vol. xxxii. p. 145.
Third Series. Vol. 11. No. 68. Oct. 1837. 3 F

402 Intelligence and Miscellaneous Articles.

EDWARDSITE, A NEW MINERAL.

Dr. Shepherd, Prof, of Chemistry, South Carolina, gives the an-
nexed account of this substance :

Mineralogical description, — Primary form. Oblique rhombic
prism. M on M= 95° (common goniometer). Base oblique from
an obtuse edge.

Secondary form. The primary, with the acute lateral edges re-
placed by single planes inclining to the adjacent lateral faces under
137° 30' (common goniometer;. In very minute crystals, the sum-
mits are occasionally surmounted by four-sided pyramids whose
faces correspond to the lateral edges of the prism.

Cleavage parallel to the bases sometimes distinct, but more com-
monly uneven: in the direction of the longer diagonal very perfect.
Surface generally not very smooth, but nearly of the same quality
on the different faces.

Lustre vitreous to adamantine. Colour hyacinth- red. Streak
white. Transparent to translucent.

Hardness=4-5. Sp. gr.=4'2. ... 4*6

Chemical description. — Alone before the blowpipe, in very thin
fragments, it loses its red colour, becoming pearl grey with a tinge
of yellow, and fuses with great difficulty on the edges into a trans-
parent glass. With borax, in little fragments, it turns white and
gradually dissolves, forming a globule which is bright yellowish
green while warm, but colourless when cold. When powdered, it
is acted upon very slightly, by aqua regia. A small quantity placed
on platinum foil and moistened with sulphuric acid, tinged the flame
of the blowpipe green.

General observations. — The crystals are rarely above one third of
an inch in length by one sixth in breadth. The replacement of the
acute lateral edges is deep, imparting to the prism a flattened ap-
pearance, except in the case of very minute crystals surmounted by
pyramids; these scarcely exhibit any alteration of the primary prism.
The terminations of the larger crystals are always incomplete. In
some of them, however, the cross cleavage is eminent, in which in-
stances the lateral faces exhibit cross striae parallel with this clea-
vage, analogous to certain varieties of Hornblende and Pyroxene.
The nearest approximations to the value of the angle of inclination
between the base and the prism was 100° for P on M. More per-
fect crystals, however, are needed than any I have yet seen for de-
ducing the incidence of P to the obtuse lateral edge. The diagonal
cleavage is almost as perfect as the corresponding cleavage in Silli-
manite. So close is the resemblance between the smaller crystals
above alluded to and Zircon, that on first inspection I mistook them
for that species.

The Edwardsite occurs disseminated through Bucholzite in gneiss
at the falls of the Yantic in Norwich, Connecticut. The Bucholzite
is here considerably abundant, forming apparently a small bed,
through which are dispersed also individuals of red feldspar, black
mica, and more rarely small crystals of blue corundum. The variety

Intelligence and Miscellaneous Articles. 403

of Bucholzite is intermediate in the size of its fibres between that of
Chester, Conn, (the Sillimanite,) and that found at Chester, near
Philadelphia, and denominated Fibrolite.

Having discovered the mineral above described, while occupied
along with my colleague, Dr. Percival, in the geological examina-
tion of the state, I have thought proper to name it in honour of his
Excellency Henry W. Edwards, the governor of the state; since the
survey was first recommended by his Excellency, and is still in pro-
gress under his administration.

Edwardsite submitted to analysis yielded the annexed sub-
stances :

Protoxide of cerium 56-53

Phosphoric acid 26*66

Zirconia 7.77

Alumina 4.4,4,

Silica 3-33

Protoxide of iron, glucina, and 1 , 2_ ]0

magnesia traces and loss . . . . /
Dr. Shepherd remarks that the phosphoric acid and oxide of ce-
rium are in such proportions as to constitute a basic sesquiphosphale
*of the protoxide of cerium. — Ibid. p. 162.

SILICEOUS AND CALCAREOUS PRODUCTS OBTAINED BY MEANS

OF slow actions; report by mm. oay-lussac and bec-

QUEREL, ON A NOTE OF M. CAGNIARD-LATOUR.

IVI. Cagniard-Latour states that by the means of several processes
which he has devised, and which are dependent upon slow action,
he has succeeded in forming various substances analogous to those
which are found in nature. The following are some of the results
which he has obtained.

" First Experiment. — Some lamp-black was treated with hot con-
centrated nitric acid ; the liquor after having been poured off was
exposed under a bell-glass for several months to the action of solar
light ; in proportion as the acid diminished, water or acid was added ;
by degrees siliceous concretions formed, some of which inclined to
the pyramidal form. Analysis indicated two per cent, of carbon ;
these concretions submitted in a platina crucible to the action of
caustic potash, heated by the flame of an alcohol-lamp, diminished in
size; their hardness is sufficient to scratch rock crystal.

" Second Experiment. — Some of the bog iron (Jer limoneux) of
Berry was taken ; after having reduced it to a very fine powder, it
was treated with hydrochloric acid ; the solution was diluted with
water and was filtered ; it was next put into a large retort, and a
glass capsule containing a piece of white marble was then suspended
in it. The marble was gradually attacked, carbonic acid gas was
disengaged ; oxide of iron was deposited, and crystals several milli-
metres in length having the form and principal properties of felspar
with a calcareous base.

" Third Experiment. — Milk of lime {lait de chaux) was poured
into a solution of perchloride of iron, to which had been added a
brown infusion of roasted corn. The precipitate having been well

3F2

404? Intelligence and Miscellaneous Articles.

washed in water, then mixed with this liquid, the mixture was heated
in a kind of Papin's digester until the interior pressure amounted
to eleven atmospheres; siliceous grains were precipitated produced
from the milk of lime. The matter was then taken and redissolved
anew in hydrochloric acid; the solution having been filtered, it
was again filtered through chalk of Meudon, which had been passed
through very fine cambric, by means of water, to separate the grains
of quartz from it. Oxide of iron was deposited in the chalk.
When the filtration was difficult, the liquor was acidulated. At the
end of fifteen days the Meudon whitening was again strained through
the cambric, and the part which had not passed was treated with
hydrochloric acid ; small opalascent siliceous concretions were ob-
tained, of which several have the form of crowns and are split from
the centre to the circumference ; they are not fusible with the blow-
pipe and scratch glass; those which were coloured being moderately
heated, acquired a smoky tint in consequence of the organic matter
which they contain.

" Fourth Experiment. — 125 grammes of powdered Meudon whiten-
ing were put into a glass tube about two inches in diameter, and
four feet and a half in height; the lower part of the tube was then
closed with a piece of linen rag intended to serve as a filter. Af-
terwards water was put into the tube, and the whitening was shaken
so as to mix it well. After having completely filled up the tube
with this water, some water very weakly acidulated with hydro-
chloric acid was prepared ; and in proportion as the water first put
into the tube filtered away through the whitening and the linen
upon which it rested, acidulated water was poured into the tube.
The filtered water deposited by degrees in a bottle in which it was
received, crystalline grains of carbonate of lime ; and at the same
time the linen serving as a filter, became covered over a great part
of its exterior surface with a crust which, examined with a mag-
nifying glass, had the appearance of saccharoidal marble. The
experiment lasted about three months. The quantity of whitening
of Meudon which was dissolved during the time that the filtration
continued was about 75 grammes, that is to say, a little more than
the half of all the whitening which had at first been put into the
tube." — Comptes Rendus, No. 25. June 1837.

NEW CARBURETS OF HYDROGEN, RETINNAPTHE, RETINGLE,
RETINOLE, AND METANAPHTALENE.

MM. Pelletier and Walter have examined the products obtained
during the conversion of resin into gas for gas lights; the results are
stated to be :

1st. The instant the resin falls into the red-hot cylinder there are
formed with the gas a certain number of extremely hydrogenated
compounds which have been separated by chemical analysis.

2nd. Among these substances there occur three new carburets
of hydrogen, to which the author has given the names of retinnapthe,
r&ingle, and retinole; these are all liquid : there are two solid carburets
of hydrogen, naphtalene, already known, and mitanaphtalene, a new
compound.

Intelligence and Miscellaneous Articles, 405

rto

3rd. Rdtinnapthe is a very light and volatile fluid ; its composi-
tion, determined by the density of its vapour, may be represented
by O8 H1(3. This product, M. Pelletier observes, is at least isomeric
with one carburetted hydrogen, which is still hypothetical, but which
appears to play a great part in the benzoic compounds, if indeed it
be not itself this carburetted hydrogen j it gives rise to a series of
new compounds.

4th. Retingle is a new sesquicarburet of hydrogen, which may be
represented by the formula C3(j, H34,H24 [?] ; it is susceptible of con-
version by the action of chlorine, bromine, and nitric acid, into com-
pounds which exhibit a series of new combinations.

5th. Retinole is a new bicarburet of hydrogen, the formula of
which is CG4 H32 ; it differs from the bicarburetted hydrogen of Fara-
day C-4 H1?, both in its constitution and its chemical properties.

6th. M&anaphtalene is anew substance, which differs from naph-
talene in its properties, but isomeric with its composition. It is
remarkable for its splendour and beauty, its chemical indifference,
in which property it resembles paraffine, from which it differs totally
in its properties and composition.

The substances whose properties and composition have now been
briefly stated, result from the sudden application of a red heat to
resin. M. Pelletier states, that in a second memoir he will examine
the properties of the products obtained from resin at lower tempe-
ratures.— L'Institut, June 1837.

DOUBLE SALT OF CODEIA AND MORPHIA.

M. Kcene, of Brussels, has published a memoir entitled, New Ob-
servations on a double Salt of' Codeia and Morphia ; in this he has
arrived at the following conclusions :

1st. Codeia and morphia form, with muriatic acid, a salt which
is undecomposable by ammonia.

2nd. Ammonia does not enter into the composition of this double
salt.

3rd. The quantity of morphia in the double salt is less than that
of the codeia, and according to one experiment only, as 1 to 3.

4th. Muriate of codeia and morphia in solution with muriate of
ammonia crystallizes first, and the latter remains in the mother
water.

5th. When heated, ammonia entirely decomposes the double sul-
phate of the two vegetable alkalis ; but the combination remains
stable, if during the evaporation, the ammonia is not in too great
excess.— Journal de Chimie Medicate, Juin 1837.

CARBURETS OF HYDROGEN.

M. Laurent distilled 8 to 10 pints of the oil of bituminous schistus,
and received the product in separate portions. He attempted, but
in vain, by repeatedly rectifying the same portion, to obtain an oil
the boiling point of which should be nearly constant} he procured
a dozen different oils, the boiling heat of which varied from 9
to 10 degrees from the beginning to the end. This circumstance
indicates the presence of several different bodies in the oil of the

406 Intelligence and Miscellaneous Articles,

sehistus ; the author examined several which differed in the point
of ebullition.

Oil from 176° Fahr. to 185°.— This oil is the most volatile. It
possesses all the properties of naphtha. On this account the author
would have felt disposed to consider the product really as naphtha,
and the bituminous sehistus as the source of it -, but its composition is
sufficiently different to cause it to be regarded as a new bicarburetted
hydrogen.

Oil from 239° to 257°. — This oil resembles the foregoing consi-
derably. M. Laurent distilled it repeatedly with concentrated nitric
acid ; he obtained in the receiver a colourless oil, the boiling point
of which varied only from 248° to 249°, and there remained in the re-
tort an altered yellowish oil which was heavier than water.

Oil from 248° to 249°-8.— This oil, which results from the action of
nitric upon the preceding, had the following properties : it was co-
lourless and very fluid. Neither the nitric, hydrochloric, nor sulphu-
ric acid acted at all upon it. Its specific gravity was 0753 at 59°
Fahr. It yielded by analysis

Carbon 86*'2

Hydrogen .. 13*6 998

The constancy of its boiling point induces the supposition that
this is a new bicarburetted hydrogen.

Oil of 336°. — M. Laurent examined whether at about 336° he could
not obtain eupion, and he set aside some oil the boiling point of which
varied from 332° to 338°. On comparing it with eupion, he found no
difference between them -} by analysis he obtained the following results :

Eupion. Oil at 336°.

Carbon 85*3 85*6

Hydrogen 15-1 14*4

100-4 100-0

It is then evident that all circumstances agree to prove, that

eupion is a product of the distillation of bituminous sehistus.

The author made a mixture of different oils, the boiling point of

which was between i 85° and 6G2° (302°?). He analysed it after having

treated it with sulphuric acid and potash, and he obtained the an-

nexed results: Carbon g5.5

Hydrogen 13-5 100-

On comparing all these analyses and that of paraffine, it will be
observed that the different bodies contained in the oil of sehistus
have the same composition as bicarburetted hydrogen within a few
thousandths.

AMPELIC ACID.

This acid is obtained by boiling with nitric acid the oils whose boil-
ing point is between 176° and 302°. On evaporating the acid, white
flocks of ampelic acid separate on cooling. This substance is white,
inodorous, very slightly soluble even in boiling water j alcohol and
aether dissolve it readily. It fuses at a temperature above 498°, and
it sublimes into a whole mass consisting of minute acicular crystals.
It is dissolved by concentrated sulphuric acid ; water decomposes the
solution. With the alkalis it forms very soluble salts.

Intelligence and Miscellaneous Articles. 407

AMPELIN.

This is a remarkable substance, and it is distinguished from all
other bodies by its similarity to oils in some of its properties, and
by its solubility in water. In order to prepare it, oil of schistus,
the boiling point of which is between 392° and 536° is to be agitated
with concentrated sulphuric acid ; this is to be poured off, and there
is to be added I- 1 5th to I -20th of its volume of a solution of pot-
ash ; the whole is to remain quiet for twenty-four hours ; at the end
of this time there are formed in the bottle two strata, and the lower
one is more bulky than the solution of potash employed ; this is to be
separated, diluted with water, and mixed with sulphuric acid ; the
ampelin separates and rises to the surface of the solution.

Ampelin resembles a fluid fixed oil ; it is soluble in alcohol, and
aether dissolves it in all proportions. When subjected to a tempera-
ture of 6\S°it does not solidify. It dissolves in pure waier in all pro-
portions : when submitted to distillation, it decomposes, and yields
water, a very limpid colourless oil, and a coaly residue. — L'lmthtut,
June 1837.

ACTION OF COLD AIR IN MAINTAINING HEAT.

I believe it is not generally known that nail-makers are in the
habit of supporting the heat of the iron, when hammering it into
form on the anvil, by blowing a current of cold air upon it.

An opportunity accidentally presenting itself sometime since near
Birmingham, I asked a nail-maker to show me the operation, which
he readily did, observing that to do it with the greater effect he
would put an additional weight upon his bellows. He also men-
tioned that it was requisite to employ the iron at a very high tem-
perature, or otherwise the cold air instead of maintaining and in-
creasing the heat would quickly cool the iron. The efficacy of the
current of air and the necessity of making the iron very hot when
employing it, were rendered as perfectly evident as the use of bel-
lows in increasing the combustion in a common fire. — R. P.

METEOROLOGICAL OBSERVATIONS FOR AUGUST 1837.

Chiswick. — August I. Rain. 2. Cloudy. 3, 4. Fine. 5, 6, Very fine.
7 — 9. Fine. 10. Overcast. 1 1 — 13. Very fine. 14, 15. Very hot.

16. Cloudy. 17. Foggy. 18, 19. Hazy: sultry. 20. Fine: slight

showers: cloudless at night. 21. Fine. 22. Overcast : sultry with

showers: heavy rain at night. 2:3. Rain. 24. Hazy: fine. 25. Very
fine. 26. Slight haze : rain with thunder. 27. Very clear : fine.

28. Fine. 29. Rain. 30. Heavy rain. 31. Clear : very fine.

Boston. — August 1. Cloudy. 2. Rain. 3. Fine : rain a.m. 4. Fine:
rain with thunder and lightning a.m. 5 — 9. Fine. 10. Cloudy.

1 1 . Cloudy : rain early a.m. 12. Cloudy. 13 — 16. Fine. 17. Cloudy:
rain in torrents early a.m.: rain with thunder and lightning p.m.
18, 19. Cloudy. 20. Fine : rain early a.m. 21, 22. Cloudy. 23. Rain.
24. Cloudy. 25. Fine. 26. Cloudy : rain early a.m.: rain a.m.

27. Fine. 28. Cloudy. 29. Rain. 30. Cloudy : rain early a.m. :

rain a.m. 3 1 . Fine.

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THE

LONDON and EDINBURGH

PHILOSOPHICAL MAGAZINE

AND

JOURNAL OF SCIENCE.

4.

[THIRD SERIES.]

NOVEMBER 1837.

LI I. Remarks upon the Botanical Affinities of Orobanche.
By John Lindley, Ph.D., F.R.S., $r., Professor of Botany
in University College London.*

f" DOUBT whether there is any part of natural history in
A which it is so difficult to distinguish between the relations
of affinity and analogy as in systematic botany. It is, I con-
ceive, to this cause that we must ascribe the widely different
opinions entertained by botanists upon the manner in which
the natural orders of plants should be arranged, and especially
upon the sequences in which they should stand. It is only
by a gradual determination of this very difficult point that
we can hope to discover the true principle of classifying
Exogens ; a point of no little importance, considering how
extensively the present fundamental distinctions of Polypetala?,
Monopetalae, and Apetalas or Incomplete, interfere with
affinity.

Supposing this opinion to be well founded, then, every
case in which errors in regard to affinity can be made out
becomes of great interest ; I therefore beg leave to point out
what I conceive to be a general mistake concerning the affi-
nities of one of our British genera.

The genus Orobanche is placed next to Scrophulariacece,
or considered a member of that order, by almost all systematic
botanists. M. Kunth indeed placed it (Handbuch der Botanik,
p. 411) between Gesneracece and Solanacea?, but he assigned
no reason for so doing. Subsequently Professor Schultz as-

* Communicated to the Meeting of the British Association at Liverpool,
September 1837.

Third Series. Vol. 11. No. 69. Nov. 1837. 3 G

4 1 0 Prof. Lindley's Remarks upon the

serted that Orobanchacece have the flowers of Personates and
the fruit of Gentianacea?, and he accordingly stationed the
order between Gentianacea? and Gesneracea? (Naturliches Sy-
stem, p. 395) ; and two years afterwards the Russian naturalist
Horaninow placed the order under the name of Phetypaeacece,
between Monotropacece (confined to the genus Monotropa)
and Gesneracea?, stationing Gentianacea? next the latter and
separating the whole from Scrophulariacea? by twelve natural
orders {Prima linea Systematis Natura?, p. 73). It does not
however appear whether these two last botanists formed their
opinion from a correct knowledge of the real nature of the fruit
of Orobanche; it would rather seem that they were led to their
conclusion by the parietal placentation of that genus, a cir-
cumstance of no great consequence.

The great points of resemblance between Orobanche and
Scrophulariacece are its monopetalous didynamous flowers and
bicarpellary polyspermous fruit ; and it is these which have led
to the general opinion that the two genera are closely allied.
Such marks of agreement are doubtless important; but they
maybe overbalanced by circumstances of disagreement of more
importance. One of these is the position of the carpels with
respect to the axis of inflorescence. In the whole category of
personate, labiate, or irregular plants, the carpels stand fore
and aft with respect to the axis ; while in Gentianacea?, and
those orders which form what is generally reckoned the op-
posite symmetrical series, we have as universally the two car-
pels placed laterally. In this striking character Orobanche
agrees with the latter series. Now as a didynamous structure
is not universal in the one series, while the position of carpels
is constant through both series respectively, we must assign the
greater importance to the latter character, and hence Orobanche
would be removed, far from Scrophulariaceae and their allies,
to the series represented by Gentianacea? \ of which this genus
would be a didynamous form, analogous to what frequently
occurs in the supposed opposite series.

But there is an essential point for consideration still be-
hind. Botanists generally lay some stress upon the presence
or absence of albumen as a mark of affinity between plants,
even although the character, as it is usually understood, is con-
fessedly very subject to exceptions. I have however endea-
voured in another place to show, that when albumen becomes
so abundant as to form the principal mass of the seed, it ac-
quires a very different value from what it possesses when a
mere stratum lying between the embryo and testa. In the
former case it seems to be essential to the very existence and
reproduction of the species; in the latter it may be regarded

Botanical Affinities t/ Orobanche. 41 1

as a mere residuum of the nutrient mucilage in which the em-
bryo is originally generated. If this be so, then it will follow
that the excessive abundance of albumen is a high physiolo-
gical character, which must be considered paramount to all
peculiarities in the mere arrangement of the floral organs with
respect to each other; lor the latter, so far at least as the
calyx and corolla are concerned, cannot be supposed to have
any essential connection with the function of reproduction.

Now Orobanchacea? differ from Scrophulariacea? in their em-
bryo being very minute and their albumen extremely copious.
In these respects they again correspond with Gentianacea?.

Altogether agreeing with Orobanchacea? in the large mass
of their albumen, and in their brown scaly parasitical habit,
we find Monotropacea?, placed in a distant part of the system
by everybody except Horaninow. To this botanists have
been led by the hypogynous stamens of the one order and the
epipetalous stamens or the other; a character which so often
produces artificial results, and which, I think, even the French
school will be compelled to abandon as a great means of
systematic distinction.

The supposed relationship ofMonotropa to Ericacea? through
Pyrola, may seem an objection to the approximation of the
former genus to Orobanche and Gentianacea? \ and if it were
certain that Pyrola was related to Ericacea the objection
would be a good one. But Pyrola differs from Erica cea? in
its albumen, just as Gentianacea? and their allied orders differ
from Scrophulariacea? \ and I cannot but regard the placing
Ericacea? and Pyrolacea? in contact as another of those false
approximations by which our ideas of classification are so
much deranged. This is not the place to enter upon such a
discussion, or I should be prepared to show that Pyrolacea?
are more nearly allied to Droseracea?, and Ericacea? to Rntacea?,
than to each other. Pyrolacea? are related to Ericacea? chiefly
by their hypogynous stamens, porous spurred anthers and
indefinite seeds, for it is an arbitrary application of terms to
call them monopetalous. They are different in their whole
habit, the organization of their seeds is essentially dissimilar,
and the Monotropacea? have not even porous anthers. But
on the other hand they stand nearly related to Orobanchacea?
in their tendency to become leafless and parasitical, in the
placentae being half parietal in Monotropa, in their anthers
having usually the spurs of Orobanche, and most especially in
the proportion borne by the albumen to the embryo.

I would therefore submit that, for the reasons now assigned,
Pyrolacea? (including Monotropacea?), Orobanchacea? and Gen-
tianacea?, instead of standing distantly apart in the natural

3 G 2

412 Remarks upon the Botanical Affinities o^Orobanche,

system, must be considered nearly related members of the
same natural series.

I am unwilling to dismiss this subject without adverting to
the placentation of Orobanchacece. That their capsule con-
sists of two carpels standing right and left of the axis of in-
florescence, and with the margins not inflected in the form of
dissepiments, is incontestable. Yet in Orobanche and Phely-
pa?a the capsule has four placentae, placed equidistant in pairs
upon the face of each valve or carpel, and considerably within
the margin. In Epiphegus each carpel has two intramarginal
placentas, which diverge from the base upwards, and terminate
before reaching the apex. In Lathrcea there is to each valve
but one placenta, which may be regarded as two confluent
ones occupying the very face of the dorsal suture of the car-
pel. And finally in JEginetia indica, and I believe in JEgi-
netia abbreviata also, the placenta is in like manner confined
to the axis of the valve, occupying the same position upon the
carpels as in Lathrcea, but broken up into a number of pa-
rallel plates of unequal depth, over the whole surface of which
multitudes of minute seeds are distributed. If we connect
these facts, about which there can be no sort of question, with
the well known placentation of Flacourtiacece, Nymphaacece,
and Butomacece, we shall find that they invalidate a general
carpological rule, that the placentas belong to the ventral su-
ture of a carpel, and consequently alternate with the dorsal ;
and we shall have to admit that the position of the placentas
with regard to the margins of the carpel is reducible to no
certain rule, but depends upon specific organization. Con-
sequently we shall no longer be unable to account for the un-
usual situation of the placentas opposite the stigma, in Papaver,
(as M. Kunth has lately noticed) in Parnassia, or elsewhere.

We ought not indeed to be surprised at coming to this
result; for if the ovules are, as botanists generally believe
them to be, a modification of buds, then the uncertainty in
the position of the placentary lines will only be conformable
to the uncertainty in the origin of buds from leaves. If in
Bryophyllum, Malaxis paludosa, and most other cases they
usually spring from the edge of the leaf, they also arise from
its surface in ferns; and in the famous case of the Ornitho-
galum leaf mentioned by Turpin, they were found issuing in-
discriminately from all parts of its face.

t 413 ]

LIII. Further Observations on the Structure of the Solid Ma-
terials found in the Ashes of recent and Fossil Plants, By
the Rev. J. B. Reade, M.J*

TN every inquiry connected with the physiology of plants, it
will be necessary to bear in mind that " the chief end and
object of the various processes into which the function of
nutrition may be divided, is the manufacture of the materials
which are ultimately to be assimilated into the vegetable struc-
ture, and by which it is to be nourished and developed in all
its partsf." In the practical application of this important
principle all writers on physiological botany, whether in En-
gland or on the Continent, have adopted the opinion that
carbon alone, fixed under the form of a nutritive material, is
elaborated for the development of all parts of vegetable struc-
ture. " The solid materials," says M. Biot, " the fixation of

which constitutes the skeleton of the plant may be known

by the analysis of the dead or withered vegetable, but even
among these we have to distinguish those which are essential
to the existence of the plant and those which have been acci-
dentally raised from the earth by the roots with the water in
which they were dissolved." " I shall be careful, therefore,"
continues M. Biot in his Analysis of the Vegetation of the
Graminece J, "not to commit myself in these complex ques-
tions, for which all the assistance of chemistry and of the mi-
croscope is scarcely sufficient. I shall confine my remarks to
a few of the alimentary products of plants which are known to
be composed by them, and conveyed into their various parts,
whilst undergoing the metamorphosis produced by vitality."

Among the solid materials represented by M. Biot as ac-
cidentally taken up, Professor Lindley ranks earths, salts, and
metals. In fact, he considers all principles which cannot be
referred to either hydrogen, oxygen, carbon, or azote to be
foreign to plants. (Introduction to Botany, book ii. chap. 3.)
" There are, however, some experiments," he adds, " which,
if they could be depended on, would materially weaken these
hypotheses. Schrader grew barley and rye in well washed
flower of sulphur moistened with distilled water: they were
afterwards analysed, and found to contain silex, lime, and
magnesia as well as oxides of iron and manganese. The same
plants produced in earth did not yield a greater weight of
ashes than those grown in sulphur; and these experiments
are confirmed by those of Braconnot as recorded in the Jn-

* Communicated by the Author ; whose former paper on the same sub-
ject will be found at p. 13 of the present volume.

f Cabinet Cyclopaedia. Henslow's Principles of Botany, p. 227.
\ Scientific Memoirs, vol. i. p. 585.

414? The Rev. J. B. Reade's^wr/for Observatiojis

jialcs deChimie, vol. lxi. p. 187 Both these observers

conclude that these foreign principles were produced by the
organic power of vegetation." Unfortunately, however, these
experiments, and others similar to these, though conducted by
able naturalists, have as yet failed to gain any very general ac-
quiescence in the conclusions which are drawn from them.
And this arises from the gratuitous supposition that not only
undetected sources of error may possibly have existed, but
that the very presence of foreign matter in the ashes proves
error to be unavoidable.

The facts which I have already brought forward, in my
former paper, have led me to adopt the conclusion of Bra-
connot, and to dismiss, as altogether untenable, any supposi-
tion of accidental introduction with respect to the elements of
vegetable structure. For, if it is not to be doubted but that
the presence of organization is direct evidence of the pre-
sence and agency of life, and that every organized portion
of a plant is a proper product of the power of vegetation,
then it will follow, that the place which the solid materials
occupy is an important and an appointed one, and we shall
be warranted to say, under a more extended application
of Professor Henslow's own remark, that the process of re-
spiration prepares the organizable materials*, whether car-
bonaceous, siliceous, saline, or metallic, from whose subse-
quent elaboration are derived those infinitely varied condi-
tions of organized matter which are essential to the develop-
ment of the numerous tribes of plants; and here I cannot
but add in the eloquent language of this author, that " from
these same materials are constructed those organized sub-
stances which seem to stand as portals to the intellectual and
spiritual world — channels of direct communication by which
reason and revelation may tell the frail tenants of a few mould-
ering atoms, of that more glorious condition which will as
certainly be their heritage hereafter as their hopes and yearn-
ings after immortality are within the actual experience of their
present state."

On communicating the nature and result of my experi-
ments to Professor Henslow I was gratified by receiving the
following reply: " Mr. R. Brown, with whom I have had
some conversation upon the subject of your letter, confirms
your conclusion that silica enters as an organizable product
into the structure of plants, and I have now no doubt of the
fact from what you and he have stated, though I had not sus-
pected it before. Mr. Brown told me that he had long since
made experiments similar to yours, but had never published

* Principles of Botany, p. 202.

on Structure in the Ashes of Plants. 415

them, and I had not heard of them." I have myself also been
favoured by Mr. Brown with some account of his experiments.
He showed me in the ashes of one plant, what I have never
seen elsewhere, a very beautiful form of siliceous cellular
structure, having the walls of the cells covered with minute
siliceous granules ; and in another plant, owing to the pre-
sence of some alkaline product, the silica which it contained
was readily fused, and Mr. Brown was therefore able, by
careful incineration, to procure perfect spherical lenses.

Having now satisfactorily ascertained that the siliceous or-
ganization of recent plants is not destructible even under the
blowpipe, it appeared to me to follow, as a natural inference,
that the less intense heat of a common fire would not destroy
the siliceous organization in the fossil plants of coal. Ac-
cordingly, I find in the white ashes of coal all the usual forms
of vegetable structure, viz. cellular structure, smooth and
spiral fibre, and annular ducts. An engraving of some of
these forms accompanied my former paper, and perhaps a
still more accurate idea may be given of them if I refer to
the late Mr. Slack's drawings of the tissue of plants in the
Transactions of the Society of Arts, vol. xlix. plate 6. The
elementary organs represented by Mr. Slack possess of course
their due admixture of carbonaceous matter, and there can
be no doubt that the removal of the carbon, by fire, would
be universally supposed, a priori, to be accompanied with the
destruction of the tissue. But so far from this being the case,
the most delicate markings remain undisturbed, and I can
confidently refer to figures 7, 12, 21 b, 23, 26, 27, 28, 30, as
most accurate representations of the vegetable forms which
occur in the white ashes of coal.

The vegetable origin of coal, which even at this day is, by
some persons, admitted rather than believed*, is thus clearly
proved, and from a comparison of the ashes of coal with those
of recent plants, some further insight might probably be
gained into the nature of fossil vegetables. To mention only
one instance, I have already ascertained that the lumps of
carbonized matter which occur abundantly in the upper sand-
stone near the Spa at Scarborough, are in all probability por-
tions of the stem of some arundinaceous or gramineous plant.
The structure of the epidermis is precisely similar to that
of the oat, consisting of parallel columns set with fine teeth,
dove-tailing, as it were, into each other, while the underlying
tissue consists of cubical cells, a thin horizontal section ex-

[• In order, however, to obtain complete ideas of the nature of coal,
it will be requisite to compare Mr. Reade's results, as above, with Mr.
Hutton's " Observations on Coal," Lond. and Edinb. Phil. Mag., vol. ii.
p. 302.— Edit.]

416 Observations on Structure in the Ashes of Plants.

hibiting a series of squares. The vegetable forms which are
respectively furnished by the BIyth, Newcastle, and Barnsley
coal appear to be so different, that I think by the aid of the
microscope it would be almost possible to assign an unknown
specimen to its proper locality; and this possibility cannot
but have its due weight with the geologist. From these facts
it is evident that the true framework and basis of vegetable
structure in the plants of coal is not only entirely independent
of carbon, but that it has also resisted the bituminous decom-
position which has converted all the carbonaceous materials
into a highly inflammable substance.

I find, upon further investigation, that silica is not the only
material which forms the framework of plants. Lime and
potash also occur as vegetable skeletons. The ashes of the
calyx and pollen of the mallow, for instance, consist of organ-
ized lime, and the ashes of the petals of the rose consist of
organized potash. The latter quickly deliquesce, and upon
the addition of nitric acid, permanent, crystals of nitrate of
potassa are readily formed. The ashes of the pollen of the
geranium also consist of potash. Hence, it is no longer " a
great question," to use the words of Dr. Dalton, " whether
potash is a constituent principle of vegetables or formed du-
ring their combustion*;" for it is evident, from the facts now
adduced, that potash, lime, and silica equally enter as organ-
izable products into the structure of plants.

In consequence of the medicinal properties of some plants
being similar to those of the fixed materials which enter as
organizable products into their structure, perhaps we may
fairly ask if there be any necessary connexion between the
medicinal properties of plants and the nature and properties
of their solid materials. It is obvious that this question could
not be entertained so long as the solid materials of plants,
carbon alone excepted, were looked upon as foreign matter,
accidentally introduced.

It has been objected by some to whom I have communi-
cated my opinions that the siliceous structure in the ashes of
gramineous plants arises from the agency of heat and is due
to crystallization ; and others again have supposed that the
process of respiration not only causes a large deposition of
silica on the epidermis, but also leaves a similar coating upon
the organs of the vascular tissue. The first of these objec-
tions is at once and easily removed by showing that in an un-
burnt portion of the husk of oat, for example, when placed in
Canada balsam, we can trace the very same series of siliceous
columns which the burnt specimen exhibits ; and that, in fact,
the similarity is so great that they have often been mistaken
* Dalton's Chemical Philosophy, vol. i. p. 472.

On the Wave-surface in the Theory of Double Refraction. 417

the one for the other. The second objection has apparently
more force, but I am able to prove that the vessels are not
coated with silica, but are actually composed of silica, by
showing that if the silica be removed, no trace of vessel re-
mains. I could wish to give particular importance to the
mode of working out this result, and to some of the facts con-
nected with it, because much light appears to be thrown upon
the nature of a new and beautiful portion of vegetable struc-
ture, I mean the system of, apparently, small cups, which are
placed along the siliceous columns of gramineous plants*.

In order to effect the removal of silica without disturbing
other parts of the plant, I placed a small portion of one of
the lower leaves of a stalk of wheat for upwards of twelve
hours in caustic potash. After removing the potash by di-
lute muriatic acid, I mounted half of the specimen in balsam,
and then expelling the carbon from the other half by the aid
of a spirit-lamp, I inclosed this portion also in the same sub-
stance. These I compared with each other and with the ad-
joining part of the leaf in its natural state. The caustic potash
had effected the entire removal of the system of siliceous ves-
sels between the ribs of the leaf, but the small cups which
are duly arranged along the siliceous columns remained un-
disturbed. These cups, therefore, are not composed of silica ;
neither are they carbonaceous, for after resisting the action of
potash, they resist also the action of fire. This is not the
case with the ducts, &c. which form the ribs of the leaf; they
are readily carbonized and dissipated. But after the car-
bonaceous parts have been thus expelled, and these cups alone
remain, if then a sufficient degree of heat be applied to effect
their fusion, they leave upon the platinum spoon a permanent
light-blue stain. It would appear, therefore, that the metallic
oxides, which are always found in the ashes of wheat, exist
in the plant under an organized form, and are obtained by
incineration from this system of cups. And, hence, I con-
clude generally that earthy, saline, and metallic ingredients
enter as organizable products into the structure of plants.
Peckham, Oct. 2, 1837.

LI V. On the Wave-surface in the Theory of Double Refraction.

By J. W. Lubbock, Esq., F.R.S.f
QINCE Fresnel's discovery of the wave-surface published
^ in his admirable paper on Double Refraction (Memoires
de V Institute tome vii.) much has been done to elucidate this

* See the figure, Plate I. Phil. Mag., July 1837.
f Communicated bv the Author.

Third Series. Vol. 11. No. 69. Nov. 1837. 3 H

418 Mr. Lubbock on the JVave-surface in

subject by eminent mathematicians ; perhaps however it may
not be uninteresting to return to Fresnel's reasoning through
which the equation to the wave-surface was originally esta-
blished, so as to facilitate the comparison of Fresnel's ideas
with those which have been since developed by M. Cauchy,
and by other philosophers*. With this view I have drawn up
the following very brief remarks. It seems to have been ge-
nerally considered that M. Cauchy's wave-surface is identical
with that of Fresnel, but I confess that I do not think that
this point has been sufficiently considered ; and indeed it has
already been asserted by Mr. Kelland that little construction
beyond the explanation of dispersion can be put upon M.
Cauchy's results, from their great complexity.

Let the displacements of the particle m in the directions of
*>y>*he £,ij, ?, and those of m', ? + A £,3/ + At/, ? + A? at the
end of the time t9 then

d2£ r

-~ m m2| (r<f> -f i>(r)Ax*} A£ t^rAj/A^Ar)

-f- \J/r Ax Az A? \
?? = msf^rAyAxAg + [<p r + +(r Af} A>j

-f tyr Ay A 2A5 r

d2 £ f

— -J- — xt\ Si tyr Ax Az Ag + ^r Ay A z A»j

dr L

+ {$r + iKr)A**} A?}.

These are M. Cauchy's equations, Exercises, vol. iii. p. 192:
they are also given by Mr.Tovey, L. & E.Phil. Mag., vol. viii.
p. 9; and by Mr. Kelland, Cambridge Trans., vol. vi. p. 158.

The remarks of Fresnel, p. 85 to 95, Mem. de V Institute
vol. vii. amount to showing that these equations may, when
the axes of elasticity are taken for the coordinate axes, be re-
duced to the form

i = m S <[<P r + * (r) A/ j^A 13

!& =lti:{^ + ^(r)A^JA5.

[• Prof. Powell's " Abstract of M. Cauchy's Views" appeared in Lond.
and Edinb. Phil. Mag., vol. vi. p. 16, et seg.- Edit.]

a

the Theory of Double Refraction. 419

If A £2 + A >j2 + A ?* = A g\ and if X, Y, Z denote the
angles which the direction of displacement makes with the
coordinate axes,

A £ = A g cos X Ayj = A g cos Y A ? = A g cos £,

-X", Y, 2 being the same as in Fresnel's notation,
cos2 X + cos- Y + cos4 2=1.

The simplest case, and I believe that implicitly intended
by Fresnel, is when the amplitude A g depends only upon the
distance ;• from the origin, then

-€ A r4 + &c.

1 .2.3.4 dr
neglecting the sums of the odd terms *

ttl 4> r A r, m v[> r A .r2 A r, &c.
we find equations of the form

ff|-« a* cos 2 jU + a« cos X #4

' dr dr dr

T<.- = ^cosr^l + i^cosr-^

\f

dt4 d ir dr

a* = -2- 5* -f $ r + ($r)Af JAr«
a2 = i^|$r + (*r) AfJAr
#> = 3£ S -f $ r + (*r) A3/2 "I Ar*

I)2 = ^-^*^r + (*r) A/ J.Ar4
c* = B-xf Qr + (4,r) a** \Ar9

0* = JL;? j"^r + (vlrr) As2| A r4

a9, &2, c2 being constant and the same as in Fresnel's notation.

* Mr. Kelland makes 2 <p (r) I x* = 2 <p (r) fy2 = 2 <p (r) 5 x*.

Cambridge Trans., vol. vi. p. 159.
But this I apprehend is a different case from that contemplated by Fresnel.

3 H2

420 On the Wave-surface in the Theory of Double Refraction.
dae vd*£ vd3>j „ d2?

Tt* = cos x d> + cos Y dF + cos z if?

~f- = «fa2 cos2 X + 62 cos3 Y + c2 cos2 s}-0

+ /a2 cos8 X + b3 cos3 Y + C2 cos2 *}- ^

If *>2 = «9 cos3 X + 63 cos3 Y + c2 cos9 %

ti2 = a2 cos2 X + b2 cos2 Y + C2 cos2 2

d ** d r* + U d r* *

This equation is readily integrable if w and il are constant,
that is, if the direction of the displacement be invariable ; and
p may be expressed by a |eries of terms similar to

(a sin kr-\-b cos Jcr) sin n t -f («' sin Jcr + U cos £ r) cos w £,
and represents a wave of light moving in the direction of r

with the velocity -j-9

k ~V\ 2.3.4 t;2 J '

See Mr.Tovey's excellent paper, L.&E. Phil. Mag. January

1836.

Fresnel does not implicitly take into consideration the term

fo2 d*e

4% which according to M. Cauchy is necessary to explain

dispersion. We have then
d3e „ d2

9 2 a 9

- — V2 *r4r V =

d*2 dr2 k '

Fresnel supposes that the quantity v2 will be constant when
the force revolved in a direction perpendicular to the direc-
tion of displacement A g is also perpendicular to a given plane,
and he shows that this will be the case precisely when the
quantity v2 = a2 cos3 X+b* cos2 Y+c2 cos3 Z is a maximum
or minimum. If the given plane is parallel to the plane

nx+ny+lz — 0.

Fresnel finds by geometry and without further assumptions
the equation

(a2-tt3) (c2-uO w2+ {b*-v2) {c*-v2) m1

+ («2-u2) (b2-v2)l* = 0.

The calculation of Fresnel's equation to the wave-surface

is also now a purely geometrical problem which is easily

effected by the elegant artifices suggested by Mr. Smith in

On the Composition of Vegetable Membrane and Fibre, 42 1

the vith volume of the Transactions of the Cambridge Phi-
losophical Society, p. 85.

This equation to the wave-surface is

(.r2 +j/2 + *2) («2 x* + b*f +c2 z*) - a2 (b* + c2) &
-^(a2 + c2)<y2-c9(a2 + i2)22 + a262c2 = 0.

The coordinate axes being those of elasticity.

M. Cauchy has arrived at a similar equation, which is given
at the foot of page 63, vol. v. of the Exercises. M. Cauchy
seems to consider this equation identical with that of Fresnel.
See Memoir es del 'Institut, torn. x. p. 312. See also Mr.
Lloyd's excellent Report on Physical Optics, Fourth Report
of the British Association, p. 391. In order that this may be
the case I apprehend that it would be necessary to have
P in M. Cauchv's notation identical with a2 in that of Fresnel.
Q b*

R c*

which I confess does not seem to me to have been proved.
Moreover FresneFs wave-surface depends upon the situation
of certain fixed axes (of elasticity), while M. Cauchy's wave-
surface does not appear to depend upon them in the same
manner, and therefore I suspect that the conclusions of that
eminent mathematician are so far in discordance with those
of Fresnel. I submit this opinion with great deference to
those more conversant than myself with physical optics and
with M. Cauchy's works, but at all events I think it will be
admitted that the question is of sufficient importance to de-
serve further elucidation by showing, if it be possible, that
M. Cauchy's quantities P, Q, R have the same signification as
Fresnel's a\ b\ c\

LV. On the Chemical Composition of Vegetable Membrane
and Fibre*; with a Reply to the Objections of Professor Hen-
slow and Professor Lindley. By the Rev. J. B. Reade,
M.A.
FT is stated by Professor Henslow in his" Descriptive and
■■■ Physiological Botany f" that all that is known of the che-
mical composition of the two elementary textures of plants,
viz. membrane and fibre, has been derived from experiments
made upon the gross material imperfectly separated from the
various matters which the cells and tubes contain ; that in
this state the gross material is found to be composed of the

* Read before Section D, Zoology and Botany, of the Seventh Meeting
of the British Association held at Liverpool ; and now communicated by
the Author.

f Cabinet Cyclopaedia. Henslow's Principles of Botany, p. 13.

422 The Rev. J. B. Reade on the Chemical Composition

three elements, oxygen, hydrogen, and carbon, the exact pro-
portion in which these are united being uncertain ; and that
therefore it remains to be ascertained whether the two organic
elements of vegetable structure are identical in chemical com-
position, and whether the membrane and fibre which com-
pose the cells and tubes in different parts of plants are always
of the same kind. It is further observed by the same author
that an inquiry into this subject would be one of extreme dif-
ficulty, if not qf absolute impossibility with the present resources
of' chemistry.

It gives me great pleasure to be able to lay before the
members of the British Association a few well ascertained
facts on a subject, of which the difficulty has hitherto pre-
vented it from being placed even among the debatable ques-
tions in the philosophy of botany. Having, on many occa-
sions, had the good fortune to witness the admirable tact with
which Mr. Robert Rigg, of Walworth, effects the chemical
analysis of vegetable products, I felt convinced, when I saw
Professor Henslow's remarks, that the difficulty, which has
appeared to be almost insurmountable, would be readily over-
come in my friend's laboratory*. I therefore separated the
spiral vessels which form the central column of the roots of
the hyacinth from their surrounding cellular tissue, and the
membrane and fibre thus obtained furnished upon analysis
the following results.

Spiral Vessels. Cellular Tissue.

Carbon 41*8 Carbon 39*2

Hydrogen 1-1 Oxygen 7*4

Nitrogen 4*3 Nitrogen 3*9

Water 51*8 Water 48*5

Residual matter TO Residual matter TO

100- 100-

Experiments made upon the gross material, and without
separating the fibre from its investing membrane, give hydro-
gen and oxygen in the proportion to form water. This fact,
which has been long known to Mr. Rigg, admirably confirms
the separate experiments which were made at my suggestion,
and from which it appears that the excess of hydrogen in the
fibre, and excess of oxygen in the membrane, are also so nearly
in the proportion to form water. It is also found that the
petals of the hyacinth contain an excess of oxygen, while the
pistils and pollen are marked by an excess of hydrogen. This

[* Notices of papers by Mr. Rigg on Fermentation and the Chemical
Changes of Germination will be found in Lond. and Edinb. Phil. iMag.,
vol. ix. p. 535.— Edit.]

of Vegetable Membrane and Fibre,

423

I quite expected would be the case, from observing that those
spiral vessels which line the interior surface of the hollow
flower-stalk, emerge, not into the petals but into the pistils
and stamens of the flowers.

In order to carry out this investigation still further, I se-
parated the flower-stalk of the hyacinth into four distinct parts,
among which the obvious variety both of structure and func-
tions is not more marked than the diversity of their chemical
composition. The parts to which I allude are,

The epidermis with its stomata.

The soft, bright green cellular tissue beneath the epidermis.

The compact column of ducts and fibre forming the main
support of the stalk.

And the spiral vessels which line the inner surface of this
hollow column.

Mr. Rigg has furnished me with the following analysis of
these different portions of the plant.

Analysis of the Flower-stalk of a Hyacinth grown in Water.

Carbon.

Hydro-
gen.

Oxy-
gen.

Nitrogen.

Water.

Residual
matter.

Epidermis with sto- "|

mata, dried at >

41-7

20

40

50-8

1-5

100

100°Fahr J

Cellular tissue be- "1

neath the epider- K

41 8

.. .

21

4-1

50-5

1-5

100

mis, do. do J

Column of ducts and ~j

fibre beneath eel- V

39-2

0-5

. ..

37

55-6

1-0

100

hilar tissue, do. do. J

Spiral vessels lining ~|

the inner surface >

35-8

17

39

58-1

0-5

100

of this column, do. J

On the existence of nitrogen in these products, which is not
the least remarkable feature in these experiments, an original
memoir will be laid before the Association.

And as I have discharged my office, which is to record
facts only, and not at all to theorize upon them, I will conclude
this short notice of an inquiry, now less encumbered with dif-
ficulty, by observing that an opinion, which not long ago
was a common one*, that membrane only is the basis of the
tissue of plants, and that fibre is itself a form of membrane, is
shown by the above analysis to be decidedly erroneous.

Peckham, Aug. 28, 1837-

* Lindley's Introduction to Botany, p. 2.

424? The Rev. J. B. Reade on the Chemical Composition

Objections to the foregoing Statement, copied from the Report of
the Proceedings of the Association given in " TheAthenccum"
September 16.

" Professor Henslow observed that in his work he had al-
luded to the great difficulty of isolating entirely either mem-
brane or fibre. The cells of the cellular tissue must contain
some fluid matter in their interior, besides the fibre that lined
them externally [? internally]. Mr. Rigg had experimented
on spiral vessels which contained both membrane and fibre;
therefore the ultimate composition of membrane and fibre was
still a desideratum. Professor Lindley said it was important
that facts of this kind should be well made out. As a proof
of want of care in the paper, it might be inferred, from the
author's statements, that there were no spiral vessels in the
petals of the hyacinth ; but the fact is, they are very abun-
dant. It appeared to him that the author had mistaken cel-
lular tissue and woody fibre, for the elementary membrane
and fibre, the chemical analysis of which was so difficult."

Reply to the above Objections.

To Professor Lindley.
Sir, Peckham, Sept. 18, 1837.

I find from the Report of the proceedings of the " British
Association " which appeared in " The Atheneeum" on the
16th instant, that my short notice of the chemical composition
of vegetable membrane and fibre was met by Professor Hen-
slow and yourself with three objections, which it will be in-
cumbent upon me to remove before you can possibly attach
any value to the facts which were adduced. I therefore trust
that you will have the goodness to allow me to lay before you,
by letter, that reply which my absence from Liverpool pre-
vented me from making on the spot.

Following the arrangement adopted by Professor Henslow
in his " Principles of Botany*," it may be stated that the two
elementary textures of plants are membrane and fibre; of these
materials the two elementary organs, viz. cells and tubes, are
constructed ; and of these organs, the two elementary tissues,
viz. the cellular tissue and the vascular tissue, are respectively
composed.

It is first of all necessary to inquire how membrane and
fibre are employed in the construction of the elementary
organs ; whether they invariably occur conjointly in each of
the two kinds of organs, or whether these organs are respect-
ively composed of the one or the other only.

* Cabinet Cyclopaedia, Henslow's Principles of Botany, pp. 13,14.

of Vegetable Membrane and Fibre. 425

Now it will be found upon examination that the vesicles of
the cellular tissue are formed, with comparatively few excep-
tions, of membrane only, and though "vascular tissue," as
Professor Henslow observes*, "consists of tubes which are
also formed of membrane to all appearance identical with that
which composes the vesicles of cellular tissue" yet with respect
to the " true vessels or long tubes which more strictly com-
pose the vascular tissue," we find in the particular case of
spiral vessels, that the membrane is so slight, that " if a ves-
sel be ruptured and the spiral fibre uncoiled, no trace of the
membrane is to be seen excepting towards the conical ex-
tremity of the vessel, and also where the successive coils are
not in contact with each other f.

It therefore appears to follow that membrane may be iso-
lated by obtaining the more common form of cellular tissuej,
where the walls of the cells are not " lined externally with
fibre," and then evaporating the fluid matter contained in the
cells; and also, that spiral vessels, entirely divested of the
cellular tissue in which they are generally imbedded, form the
nearest practicable approximation to isolated^Z>r£ §.

In order then to obtain these materials in a state fit for
chemical analysis I had recourse to the roots of a hyacinth
grown in water. Each root consists of a central column of
spiral vessels surrounded by cellular tissue. When the plant is
young, the spiral vessels, having a diameter of about the j^th
of an inch, are not easily separable, even by boiling, from the
tissue in which they lie. But when the plant has arrived at
maturity, the entire column of spiral vessels having now, in
many instances, a diameter of nearly the ^jo^1 °f an inch ||,
as well as a considerable increase in the width of the spiral
thread, may by a little management (in fact, by simply rub-
bing the root between the fingers and the palm of the hand),
and without boiling, be readily drawn out of its sheath of cellular
tissue ; and each vessel is so free from any admixture of cel-

* Principles of Botany, p. 20. t Ibid., p. 21.

% " Membranous cellular tissue is that in which the sides consist of
membrane only, without any trace of fibre; it is the most common, and
was, till lately, supposed to be the only kind that exists." — Lindley's In-
troduction, p. 8.

§ " In the root of the hyacinth the coils of the spiral vessel touch each
other, except towards its extremities." — Lindley's Introd., p. 19.

|| " It is an axiom in vegetable physiology, that a part once fully formed
is incapable of any subsequent change. Thus, pith never alters its dimen-
sions, after the medullary sheath that incloses it has been once completed."
— Lindley's Introd., p. 33.

This being the case, the larger vessels must have a later formation,
and the number of vessels in the young and old roots ought to indicate
this fact.

Third Series. Vol. 11. No. 69. Nov. 1837. 3 I

4-26 The Rev. J. B. Reade on the Chemical Composition

lular tissue that it might be represented by the engraving in
your own work, Plate II. fig. 9.

With membrane and fibre isolated to this extent, Mr. Rigg
commenced his experiments; and 1 believe that I am not in
error when I state that the ultimate analysis of these textures
was thus for the first time attempted. There is no record of
similar experiments, for, as Professor Henslow justly ob-
serves *, " all that is known of the composition of these tex-
tures has been derived from experiments made upon the gross
material, which is found to be composed of the three ele-
ments, oxygen, hydrogen and carbon ;" a result which clearly
shows that the gross material referred to consisted of both the
elementary organs, viz. cells and tubes, as they conjointly en-
ter into vegetable structure.

But even allowing Professor Henslow's objection its full
force, and granting that " fibre externally lined the cells of
the cellular tissue" analysed by Mr. Rigg; and also that
" the spiral vessels contained both membrane and fibre ;" then,
bearing in mind that "it has not hitherto been ascertained
whether the membrane and fibre which compose the cells
and tubes in different parts of plants are always of the same
kindf", I would offer the result of the analysis as a proof
that the membrane and fibre which compose the cells are
essentially different, in a chemical point of view, from the
membrane and fibre which compose the spiral vessels; the
former invariably containing an excess of oxygen, and the
latter an excess of hydrogen. And thus we appear to arrive
at the chemical composition of the elementary tissues, and that
too in such a way as to be an important approximation to
the composition of the elementary textures ; for it cannot
be doubted that membrane predominates over fibre in the
cells, and that fibre predominates over membrane in the spiral
vessels.

I learn, from the report in " the Athenaeum," that you
commenced your own observations by stating, that " it is im-
portant that facts of this kind should be well made out ;" a
remark which encourages me in the hope that you will fa-
vourably receive my present attempt to substantiate the re-
sults or my friend's experiments. But you go on to charge
me with the fault, condemned by a great authority :

" Aut operae nimium celeris curaque carentis,
Aut ignorata3...artis."

For you proceed, " As a proof of want of care in the paper,

• Principles of Botany, p. 13. 1 Ibid.

of Vegetable Membrane and Fibre. 427

it might be inferred from the author's statements that there
were no spiral vessels in the petals of the hyacinth ; but the
fact is, they are very abundant" Had I been present I might
at once have obviated this objection by pointing out that it
was founded on misapprehension, and by appealing to the
words of my paper, where I state, that " those spiral vessels
which line the interior surface of the hollow flower-stalk,
emerge, not into the petals, but into the pistils and stamens of
the flowers," from which the inference would be very different
from the one you suggest.

The facts brought forward are these : The spiral vessels
of the root give hydrogen in excess, and the cellular tissue of
the root gives oxygen in excess. It is also found upon ana-
lysing different parts of the flower that the petals con-
tain an excess of oxygen, while the pistils and pollen are
marked by an excess of hydrogen. Hence, the question
arises, Is there any such connection between the root and the
flower as shall enable us to trace the excess of hydrogen in
the pistils and pollen of the flower, to the excess of hydrogen
in the spiral vessels of the root ? I answer that there is, for
it is found upon examination that those spiral vessels which
line the interior of the hollow flower-stalk proceed directly to
those parts of the flower which are marked by an excess of
hydrogen, emerging, not into the petals, but into the pistils
and stamens. And hence I wish the inference to be that those
spiral vessels which run within the hollow flower-stalk, and
contain hydrogen in excess, are a continuation of the spiral
vessels of the root, and that the spiral vessels of the petals and
leaves of the plant have their origin elsewhere. It may be
observed with respect to dicotyledonous plants that the latter
part of this conclusion would appear to be inevitable, in as
much as spiral vessels abound in the leaf-stalks (see Dog-
wood) and leaves, but "have not hitherto been seen in the
roots" Lindley's Introduction, p. 22. I would however take
this opportunity of inviting the attention of botanists to the
more accurate microscopic examination of the roots of dicoty-
ledonous plants ; for I can only conclude that spiral vessels
have not been seen, merely because they have not been looked
for. The root of the common garden mint, to instance one
example among others, contains spiral vessels in great abund-
ance. Their diameter is about ^otn °f an mcn» I will also
add that the root of the wall-flower contains a very beautiful
and hitherto undescribed form of reticulated cellular struc-
ture. It is perhaps necessary to state that in consequence of
the great similarity between the brittle annular duct and the
true spiral vessel, it is impossible to speak with decision as to

3 I 2

4-28 Prof. Kane on the Powder formed by

the smaller forms of these tissues without using a magnifying
power of at least 800 linear. I have had the advantage of
making my examination with the well-known power which
Mr. Bowerbank has received from Mr. Ross.

I believe that no part of the analysis gave Mr. Rigg more
satisfaction than the results just alluded to. In the course of
his experiments, extending to some thousands, he had here-
tofore discovered a difference of chemical composition in dif-
ferent parts of the flower of the hyacinth ; but the root, which
he had always examined in the mass, and without separating
it into its two component parts, gave hydrogen and oxygen
in the proportion to form water. I am sure, therefore, you
will readily understand the pleasure which was felt in thus
finding, for the first time, that the chemical character of the
different parts of the flower were exhibited by the present
analysis in the different parts of the root.

I will only add, without further observation, that I trust the
above remarks will convince you, that I have not " mistaken
cellular tissue and woody fibre for the elementary membrane
and fibre, the chemical analysis of which is so difficult."
I have the honour to be, Sir, yours, &c.

J. B. Reade.

LVI. On the Powder formed by the Action of Water on White
Precipitate. By Robert Kane, M.D., M.R.I.A., fyc. $c*

FT is generally stated by chemical writers, that by the ac-
-*■ tion of much boiling water, white precipitate is decom-
posed completely, red oxide of mercury being left behind.
I never could succeed in effecting this ; but the reaction that
did take place appearing to me perfectly definite, and identical
in its results at different times, I was induced to examine it
in detail.

When white precipitate is boiled in water, it is changed
into a heavy canary-yellow powder, subsiding rapidly, and
very easily dried, when it appears granular. This powder is
not quite insoluble in water ; when heated, it gives out am-
monia, azote, water, and there sublimes a mixture of calomel
and metallic mercury : it dissolves readily in muriatic or nitric
acids. Alkalies appear to have scarcely any action upon it,
except slightly altering its colour; when digested with iodide

* From the Transactions of the Royal Irish Academy, vol. xvii. ; being
§ 2 of "Researches on the Action of Ammonia on the Chlorides and Oxides
of Mercury." In L. and E. Phil. Mag., vol. viii. p. 495, we gave Dr. Kane's
" Experiments on the Action of Ammonia on the Chlorides and Oxides of
Mercury, and on the Composition of white Precipitate." The present
article concludes his observations on these mercurial compounds.

the Action of Water on White Precipitate. 429

of potassium, there is ammonia disengaged, and a brown
powder formed. To this reaction I shall hereafter recur. In
order to determine the composition of this yellow powder,
the following experiments were made : —

A. — 100 parts of corrosive sublimate were dissolved in
water, and ammonia added in excess. The mass, in place of
being filtered cold, was boiled until the light-white precipitate
was changed into the clear yellow heavy powder ; it was then
filtered, and the quantity of product determined. The liquor
and washings were acidulated by nitric acid, and precipitated
by nitrate of silver, and the chloride abstracted from the sub-
limate thus determined ; the liquor contained a very small
trace of mercury. Several experiments were made on this
plan, the results of which are exhibited in the following table :

100 parts of sublimate gave,

Exp. Yellow powder. Chlorine in liquor.

1 83-5 19*25

2 83-3 18*50

3 84-7 18-90

mean 83*83 18-89.

Now 100 of sublimate contain

Mercury 74'09

Chlorine 25*91.

Hence we see that there have been abstracted from the
sublimate three-fourths of Us chlorine ; the remaining fourth,
and all the mercury, existing in the yellow powder. We have
therefore in 83*83 parts of it :

Mercury 74*09

Chlorine 71*02

Or in one hundred parts,

Mercury 88-381

Chlorine 8*374

B. — When white precipitate already prepared is boiled with
water, there is obtained a similar yellow powder, and the su-
pernatant liquor is found to contain only sal-ammoniac. As
we know, within very strict limits, the composition of the
white powder, we can make use of this reaction to illustrate
the nature of the yellow product:

100 parts of white precipitate were boiled with water until
completely converted into the yellow powder; the liquor,
which was quite neutral, was acidulated ; and the chlorine dis-
solved precipitated as chloride of silver, from which its quan-
tity was obtained by calculation. The following table gives
the results of experiments conducted in this manner :
100 of white precipitate gave

430 Prof. Kane on the Powder formed by

Exp. Yellow powder. Chlorine in liquor.

1 90-00 5-93

2 88*50 6-50

3 90*30 6-40

mean 89*60 6-29.

But 100 of white precipitate contain

Mercury 78'60

Chlorine 13-85

Therefore 89*60 of the yellow powder contain

Mercury 78*60

Chlorine 7 56

and 100 contain

Mercury 87*95

Chlorine 8-44.

C. — 100 grains of white precipitate were boiled with water
until completely decomposed; the resulting yellow powder
weighed 91*15 grains. The liquor was cautiously evaporated
to dryness, and gave 10*23 of sal-ammoniac, consisting of

Chlorine 6*76^

Hydrogen *19>10*23.

Ammonia 3*28j

Therefore there are obtained, by this experiment, for the con-
stituents of yellow powder,

Mercury 86*23

Chlorine 7*77

Ammonia 3*83.

D. — It has been already stated, that when this powder is
heated, it is resolved into ammonia, azote, water, calomel, and
quicksilver. Having found that, by performing this operation
in a very small retort, the water and gases could be dissipated
without any remarkable loss of the other constituents, I made
some trials in this way to determine the amount of the chlo-
rine and quicksilver. For this purpose a higher temperature
is required than for the corresponding analysis of white pre-
cipitate, and the condensation of the mercurial vapour must
be very carefully effected. In other respects the manipula-
tion was the same, and the following table contains the re-
sults :

p, Quantity of Sublimed Sublimed Residue

P* Material. Residue. from 100 parts.

1 14*30 13*37 93*50

2 19*65 18-53 94*30
& 23*72 22-35 94*22

Per cent, mean 94*01.

the Action of Water on White Precipitate. 431

From this result we can easily calculate the quantities of
chlorine and mercury the residue contains, for,

Let m — the residue = 94-01

x = the quantity of chlorine

y as the quantity of mercury

a = atomic weight of chlorine = 35*42

b = atomic weight of mercury = 202*8.

This is (1.) x = m — y

x a

and (2.) — ss — - by other processes.

Then '• = -^- .*. Ibm = (a+2b)y

m—y a

, 2bm

ana y = — 7-.

y a + 2b

We thus find 100 of yellow powder, to contain

Mercury 86*46

Chlorine 7*5.5

E. — 105*28 grains of yellow powder were dissolved in mu-
riatic acid, and the solution having been somewhat diluted, was
decomposed by a current of sulphuretted hydrogen gas. The
perfectly black sulphuret was collected on a weighed filter,
and the liquor evaporated to dryness, and the residual sal-
ammoniac weighed :

The filter and sulphuret 126*71

Filter 23*00

Sulphuret of mercury 103*71, consisting of

Sulphur 14*22

Mercury 89*49.

The sal-ammoniac weighed 12*86 grs. consisting of

Chlorine 8*50

Hydrogen *24

Ammonia 4*12.

Therefore, the yellow powder consisted of
in 105*28 parts, in 100 parts,

Mercury 89*49 Mercury 85*00

Ammonia 4*12 Ammonia 3*91.

Summing up these different results, we have

Process. Mercury. Chlorine. Ammonia.

A 88*381 8*374

B 87*95 8*44

C 86*23 7*77 3*83

D 86*46 7*55

E 85*00 3*91.

* Lioo-oo.

432 Prof. Kane on the Powder formed by

And taking the mean result of all, we get, for the composi-
tion of this yellow powder,

Mercury 8680^

Chlorine 8'03

Ammonia 3*87

Oxygen and loss 1*30 J

In the processes, A and B, a small quantity of the yellow
powder was lost, in consequence of its being not perfectly in-
soluble in water. This quantity, I have reason to believe,
varied from one to two per cent, and by the means of calcu-
lation we employed, the mercury and chlorine constituents
are given above what is correct in that proportion. As far as
I can judge, by considering the circumstances of the experi-
ments, I conceive the mean to be consequently too high ; and
I believe the analysis C. by itself, to approach closer to the
truth. By it we have in 100 of the yellow powder,

Mercury 86*23 1

™orin? r-

Ammonia,

•77
;-83 f

Oxygen and loss ... 2*17 J
This yellow powder is generated evidently by the reaction
of water on white precipitate, in which one-half of the chlorine
and ammonia are converted into sal-ammoniac, a correspond-
ing portion of the mercury being oxydized. I shall compare
the results of this reaction with each of the formulae for white
precipitate that I have previously given.

2{(2Ch+Hg)-f (2NH3+ Hg)}+2H =
j(2Ch + Hg) + (3Hg + 2NH3)}+2ChNH4.

Here two atoms of white precipitate and two of water, mu-
tually reacting, give two atoms of sal-ammoniac and one of
the powder. On this idea, the yellow powder should con-
sist of Mercury 84*12^

Chlorine 7*36

Ammonia 3*56

Oxygen 4*96

These numbers, with the exception of oxygen, fall below
the lowest experimental result, and probabilities are therefore
rather against this formula being true. Let us next try the
result of reaction with that formula for white precipitate which
does not include oxygen, and supposes the ammonia to exist
as amidogene.

2{(2Ch + Hg) + (2NH2 + Hg)}+4H =

{(2Ch + Hg) + 2Hg + (2NH* + Hg)}+2ChNH\

^ 100-00

the Action of Water on White Precipitate, fyc. 433

There are here equally produced by the two atoms of white
powder and two of water, two of sal-ammoniac, and one of the
yellow powder, of which the composition should be
Mercury 85*72^

Chlo'ine TtlUoO'OO

Amidogene 3*42 I

Oxygen 3'38J

and it should yield in analysis 3*63 per cent, of ammonia.

The definite composition of this yellow powder is thus evi-
dent, and the decomposition by which it is formed perfectly
explained. We see that all the results tend to show that in
these bodies the ammonia is not united with oxide of mercury,
but rather the metal with amidogene. The perfect demon-
stration of this principle, however, must be sought for in the
other metals.

Of the Products of the Action of Alkalies in Excess on
White Precipitate.

Grouvelle and other chemists have stated that by the action
of an excess of alkali on a sublimate solution, there is pro-
duced the ammoniuret of mercury which was discovered by
Fourcroy and examined by Guibourt, and to which I shall
hereafter speedily recur ; and even Dumas states, that " the
same compound (the ammoniuret) is obtained by pouring
ammonia into a solution of corrosive sublimate, and then
adding caustic potash in excess." My anxiety to obtain pure
ammoniuret of mercury, joined to the interest of the prece-
ding investigations, led me to examine the nature of the pro-
ducts thus obtained ; and the results, as correcting an error
very generally fallen into, are worthy of being described.

When corrosive sublimate is decomposed by ammonia, the
quantity of alkali in excess does not appear to interfere much
with the reaction before described. If the liquors be cold,
there is obtained white precipitate ; and if it be boiled, the
heavy yellowish powder is produced; the liquor retaining
in the former, one-half, in the latter, three-fourths of the
chlorine of the sublimate. Again, if white precipitate be
boiled in water, rendered strongly alkaline by ammonia, we
obtain the yellowish powder, and half the chlorine and half
the ammonia of the precipitate are disengaged. Thus, water
of ammonia acts on white precipitate only as water itself does,
the nature of the reaction being the same in both instances.
Again, when white precipitate was treated with potash for
analysis, as in L. and E. Phil. Mag., vol. viii. p. 498, it has
been seen that the ammonia disengaged was but one-half what
it contained, the formation of the yellowish powder being the

Third Series. Vol.11. No. 69. Nov, 1837. 3 K

434* Prof. Kane on White Precipitate,

limit at which the decomposition stops. In these cases, how-
ever, the powder product is not so bright in colour as that
produced by the action of mere water. It does not appear to be
quite so pure, but in its properties it manifests complete identity.
Nevertheless, in order to leave no room for doubt upon the
matter, I decomposed corrosive sublimate by a great excess
of ammonia, added a strong solution of potash, and boiled
for a considerable time. The yellowish white powder pro-
duced, was separated by the filter and washed until the li-
quors ceased to affect turmeric paper: dried carefully. It
weighed from 100 of sublimate, 85 grains. When heated it
gave out water, ammonia, and azote, and calomel with me-
tallic mercury sublimed. When suddenly heated, it puffed
up, more so than the pure yellow powders, which was pro-
bably the reason of its having been confounded with the am-
moniuret which possesses a very slight detonating property.

To analyse it, 66*83 grains were dissolved in muriatic acid,
and having been diluted were decomposed by a current of
sulphuretted hydrogen gas. The black sulphuret was collected
on a weighed filter, and having been carefully dried, weighed
67*70 grains, consisting of

Mercury 58*42

Sulphur 9*28.

The liquor evaporated, gave sal-ammoniac 6*58 grains,
consisting of

Chlorine 4*35

Hydrogen *12

Ammonia 2*11.

There were thus obtained from 66*83 of this powder,

Mercury 58*42"

Chlorine 4*35

Ammonia 2*11

Oxygen and loss ... T95
But the yellow powder by water, should have given from
the formula :

(2 Ch + Hg) + 2 Hg + (2NH2 + Hg)
Mercury ...... 57*30"

Chlorine 5*00

Amidogene 2*28

Oxygen 2*25

This result proves the identity of the effect in the two cases
of the action of water and of an alkali.

Rose and Grouvelle have already shown that when dry
ammonia is passed over melted sublimate, an atom of the
former is absorbed by one of the latter, and a white mass

^66*83.

^66*83.

Prof. Meyen on the Progress of Vegetable Physiology. 435

formed. The history of its properties has been so well given
in Rose's Memoir, that it is unnecessary for me to do more
than mention my results as having been confirmatory of his.
This compound is decomposed by water giving white preci-
pitate and sal-alembroth, as may be at once seen :

4 (2 CI + Hg) + 4 NH3 =

{(2Cl-rHg)+(2NH»+Hg)}+ 2 <[(2C1+Hg)+(C1+NH<)}

[To be continued.]

LVII. A Report of the Progress of Vegetable Physiology
during the Year 1836. By J. Meyen, Professor of Botany
in the University of Berlin.*

[Continued from p. 390.]

On the Combination, Structure, and Contents of the Cells of

Plants.
^VJ^TYj come now to the observations which were made known

** last year, on the combination of cells in the higher and
lower orders of plants. Mohl f endeavours to establish the
opinion that the tissue of plants is constituted not as a col-
lection of contiguous cells grown together without any inter-
mediate substance, but that there is present a homogene-
ous substance, an organic mucus, in which the cells are im-
mersed, and by which they are connected with one another.
This combining substance Mohl calls intercellular substance,
and the discovery of it appears of such importance, that a learn-
ed botanist lately observed, that with it a new aera for vegeta-
ble physiology had arisen. Mohl \ had previously mentioned
this notion in his observations on the structure of the pollen
membranes, which Mirbel § opposed with very powerful argu-
ments. In the above memoir, Mohl endeavours to weaken the
arguments which Mirbel had advanced against his view on the
combination of the cells of plants; and demonstrates a so-
called intercellular substance, not only in the membranes of
the pollen, but even in various families of Cryptogamia, as
also in the tissue of the higher plants ; but in what degree he

* From Wiegmann's Archiv fur Naturgeschichte, 1837, Part 3. Trans-
lated by Mr. Wm. Francis.

f On the Combination of the Cells of Plants with one another. Published
as an Inaugural Dissertation in September 1835. It was then again printed,
enlarged, under the title of: " Explanation and Defence of my view of the
Structure of Vegetable Substance," with 2 plates. Tubingen 1830.

J Vide Meyen's Year's Report for 1834, p. 153.

§ Ibid., 1835, p. 101.

3 K2

436 Prof. Meyen's Report of the Progress of

has succeeded in doing this will in part be shown in the course
of this report from the observations of other botanists.

Mohl finds this homogeneous substance most clearly in the
Algae between the cells, which are combined by it into a
whole.

In the Nostochinete, Rivularice, in Protococcus, Palmella,
HydruruS) Oscillatorza, Scytonema, &c. the more or less thick
mucous or gelatinous substance is to be regarded as the
analogue of the intercellular substance in the perfect plants.
In the proper Confervae the common mucous substance has
disappeared, or only forms a very thin envelope over the
fibres, so that these are lubricated and rendered slippery by
it, but no longer combine into masses; instead of which they
possess a homogeneous external tube. Of the true Con-
fervas the Spirogyrce of Link are those which possess the
greatest mucous envelope, and in those, as also in other Con-
fervae, we can observe that this mucous substance becomes
thicker with increasing age, and that in the young plants it
is entirely wanting. According to this, the view which Mohl
has advanced on the nature of intercellular substance can
hardly be extended to this substance.

In the more compound Algae this mucous matter, accord-
ing to Mohl's observation, is not only disposed on the surface
of the entire plant, but also between the individual cells, which
had already been observed by Eysenhard and Agardh ; and
since this homogeneous substance entirely fills the intervening
space of the cells, the intercellular passages are totally want-
ing in these vegetables. In the thallus of Ferns the intercellular
substance forms a less remarkable constituent part than in the
Algae. In this case it is the cells of the outer layer becoming
transparent in water, which are connected by this substance,
so that here also no intercellular passages remain. In the
more perfect plants it is not so easy to demonstrate the pre-
sence of intercellular substance, as in these not only do
the cells lie in closer contact with each other, but since also
intercellular passages run between their parenchymatous cells.
Mohl however alleges that notwithstanding these difficulties,
we may still succeed in many cases in meeting with this mass
interfused between the cells, in greater or smaller quantities,
even in perfect plants, so that there will be scarcely any plant in
which we shall not be able plainly to demonstrate this sub-
stance in one organ or other. Mohl then enumerates a num-
ber of instances in which the intercellular substance is found
in mosses, ferns, in the wood of the Coniferae and of the Di-
cotyledones. The intercellular substance shows itself more
plainly in the protended thick-sided cells which often occur

Vegetable Physiology for the Year 1836*. 437

in the bark of the stem, or under the epidermis in the petiole
of the leaf, than between the woody cells. If we examine
this cellular mass in the stem of Sambucus nigra in diagonal
sections, the cellular cavities appear at first sight to be very
irregularly distributed in a completely homogeneous glass-like
transparent substance ; by a more accurate examination it is
however evident that this substance is not totally homogeneous,
but that it separates into cellular membranes and into inter-
cellular substance. The lines of demarcation are said to be
very fine and easily overlooked.

Our views on this point are very different from those of
Mohl. If we take very thin sections, and observe them with
a magnifying power of 1000 or 1800, with achromatic glasses,
no lines can be perceived distinguishing the exterior surface
of the cellular membrane from the intercellular substance;
but it can be plainly seen that there takes place a gradual
transition from the substance of the membrane of the cell into
the so-called intercellular substance. I will also mention an
observation which most clearly proves that the intercellular
substance of Mohl is no peculiar separately constituted sub-
stance, which is as it were diffused between the cells, but that
it belongs to the cellular partitions, and is secreted by them
when a more close connection of such cells is to take place.
If, for instance, we observe in diagonal sections the solid cel-
lular layers which clothe the leaf petiole of Beta Cicla (the
red variety is best for this purpose), we find that the so-called
intercellular substance occurs in great quantities between the
cellular layers; we however can distinguish even with weaker
magnifying powers that to each one of the surrounding cellular
membranes belongs an appropriate portion of that intermediate
substance. I could mention several other instances where the
case is precisely similar; and consequently his view of the
nature of the intercellular substance in vegetables would have
to be altered. Mohl also applies his view of the intercellular
substance to the epidermis of plants, as he considers the cuticula
with its dependents as this substance in which the cells are
sunk.

Subsequently to the appearance of this memoir of Mohl,
Valentin * also published a series of observations in which
this intercellular substance was demonstrated more or less
evidently; and these examples will be multiplied by every ob-
server. Valentin concludes from his observations that all in-
tercellular substance is found only between ligneous forma-

* On the Structure of Vegetable Membrane, especially in the secondary
ligneous layers ; in his Rcpertorkimfiir Anat. u. Physiol., vol. i. p. 9b*.
Berlin, 1836.

438 Prof. Meyen's Report of the Progress of

tions; never, on the contrary, between simple sacs in any per-
ceptible quantities ; the cause of which lies in the very exist-
ence of the intercellular substance. Valentin's observations
also show, that the intercellular substance does not exist at
the beginning, but occurs first after the commencement of lig-
nification, and must therefore certainly be distinguished from
the substance which is found around and between the sacs of
the lower Cryptogamia. We have however previously men-
tioned, that this substance is also wanting in germinating
Conferva?. Since the intercellular substance, observes Va-
lentin, appears first after the process of lignification*, it can-
not be regarded as an organic mucus which holds the cells
together. It is no less a secondary layer without the primi-
tive sac than the ligneous lamellae are within the same. It
occurs only where a considerable number of ligneous lamellae
exist. If we may use an old technical expression, the intercel-
lular substance occurs in all cases where thick-sided cells are
closely connected with one another, few or no intercellular
passages remaining.

Closely connected with this subject are the observations
which have been made on the structure of cellular membrane.
Mohl in the above-mentioned memoir has given an accurate de-
scription of the stripy structure of the partitions of the cells of the
liber of Nerium Oleander, Vincaminor, and various other plants
belonging to the families Apocynece and Asclepiadece. These
cells show in a diagonal section, as also in a horizontal one,
that their sides consist of a great number of superincumbent
membranes. The cells of the liber of Vinca throw more light on
the subject; Mohl describes them as broad, abruptly and
greatly contracted at their ends, sides not very thick, and com-
posed of several layers. In the wider parts the membrane was
covered with spiral, steep, ascending lines, and so that a part of
these lines wound round to the right, the other to the left, and
in this manner the membrane was divided into small rhorn-
boidal portions. Mohl previously supposes, that the lines are
wound in the one layer to the right, in the other to the left,
and that the layers which compose these cellular membranes
are not homogeneous, but possess a fibrous texture.

" Are we now to deduce from this aspect of the tubes of the
liber of the plants above cited," says Mohl, "the view already
entertained by Grew, that the cellular membrane is woven toge-
ther of fibres ? I do not think so. As far as we can observe of
these extremely delicate formations, discernible only with good

* The author, differing from other phytotomists, understands by ligni-
fication nothing more than the thickening of the sides of the cells by the
deposition of new layers.

Vegetable Physiology for the Year 1836. 439

instruments and under favourable light, the substance of these
apparent fibres appears to be exactly the same as that which
fills out the intermediate spaces ; and this fibrous appearance
seems to indicate not the existence of real separate fibres, but
rather a small difference in the thickness of the cellular mem-
brane : perhaps a different arrangement of the molecules at
various points, perhaps a small difference in the thickness of
the membrane causes a different refraction of light, precisely
in the same way as fibres are visible in badly melted glass."
Mohl also throws out the opinion that such a texture of the
cellular membrane is very common, as several observations
have seemed to prove to him.

Valentin (I. c, p. 89) repeated these observations of Mohl,
and has completed them in many respects. He observed per-
fectly well in the cells oftheliberof Nerium odoriim, that the dia-
gonal or rather horizontal stripes which these cells exhibit are
found entirely outside, while the spirals which cross one another
are found in different lamellae bent over each other. And in
each partition of the cells these spirals always take one and
the same direction; and for that reason they must cross in
opposite partitions. Valentin observes this structure of the tubes
of the liber and woody cells in various other cases partly known,
and partly not yet noticed, and arrives at the conclusion that
they are all without exception lignifications, and that their par-
titions are never those of the primary cellular sac alone, but
that they are also covered with ligneous lamellae. And, as
Valentin had not yet found these spiral lines in the more
simple cells and septa (in which they however occur quite as
beautiful, as I can prove in several cases,) he thinks he is able
to consider these as the consequence of the process of lignifi-
cation; the history of their development even is said to remove
all doubt on this subject.

Valentin at the same time gives a history of the formation
of the spiral stripes, which are certainly very difficult to ob-
serve in their formation. " In the centre of the tube of the
liber a very fine granular substance is perceived, the granules
of which possess for the most part a transversal arrangement.
The corpuscles of this substance at first do not allow of our
observing any definite arrangement. Subsequently they form
diagonal lines, then spiral lines, in which, however, at the be-
ginning it is still possible to distinguish the individual corpus-
cules, and which at last run on in an uninterrupted con*
tinuity."

Link* has examined the seed of the Casuarince, in refer-

* Philos. Bot.y i. p. 186.

440 Prof. Meyen's Report of the Progress of

ence to the cells which are situated under the testa, and are
regarded as a layer of spiral tubes which are easily unrolled.
Link found under these another layer or membrane consisting
of long parenchymatous cells, which are closed at one end,
and contain fibres just beginning to be evident ; but at the other
end are spiral fibres which became true spiral vessels. On
this ground Link has advanced the opinion that the cellular
membrane changes with age into spiral fibres ; this is repre-
sented in Plate III. fig. 3. of his work. I have on the con-
trary, in my recent work on Vegetable Physiology, endea-
voured to confirm the opinion that the cellular membrane is
composed of fibres having a spiral course.

In a second memoir by Valentin* the structure of the cel-
lular membrane in reference to its lamellar structure, and
in regard to the form of the dots [Tupfel) is more closely ex-
amined.

The thickening of the cellular membrane by the deposition
of new layers is called by Valentin the process of lignification,
and in the first stage only of development of this process do
the first deposited lamellae lie close on the entire surface of
the primary sac partition. Subsequently, however, at the end
of the individual development of the porous cells and vessels,
a circular gap is formed around the exterior limit of the porous
canal (Tupfelkanal dotted duct) between the first super-
posed layers of lignification, and the primary sac partition
whose exterior periphery runs in a direction concentric with
that of the porous canal, and which gradually becomes small-
er from this point up to its circumference, until both
membranes become once more fixed close to each other.
The porous canal as well as the gap above cited constantly
contained, like the interior of these ligneous cells or vessels,
an aeriform substance. Valentin then gives a more
accurate description of the great disks with double circles
which the cells of the Coniferce exhibit, and accompanies
his explanation with some figures, from which it is evident
that some error has occurred in these observations ; for it is
very easy to perceive in these formations a coincidence with
the structure of other dots ; while Valentin's representation
is quite at variance with this. For according to it, next to
the external layer of the cellular membrane is situated a
great gap, which is said gradually to contract into a fine
passage representing a dot, and to merge into the cavity of the
cell ; while, according to the observations of other botanists,

* On the various forms of the porous canal in the porous cells and ves-
sels.—Vide his Repert., $c.t p. 78—87-

Vegetable Physiology for the Year 1836. 441

the gap originates between the partitions of contiguous cells,
and indeed from a local separation of the membranes, and the
real dots , here showing themselves as the small and interior
circles, which consist of a cavity on the interior partition of the
cellular membrane raised towards the inner side.

Valentin himself confesses that the porous opening exhibits
quite different forms, not only in different plants, but also at
times in various parts of the same plant ; but nevertheless he
considers it necessary to give various denominations to the
different parts. Thus he calls the space which characterises
the formation of the gaps, and which is continued in the true
porous opening, the gap-funnel; yet in the Conifer (B^ in which
Valentin has figured this gap-funnel so very great and so
plainly, this space is not present. The opposite end through
which the termination of the porous opening enters the cavity of
the cell, he calls the entrance-funnel^ and the more cylindrical
part situated between these, the middle part.

He afterwards draws attention to the various forms of these
individual parts of the dots in various plants. I have
however not been able to find these forms so constant as
they are described. At all events it is highly gratifying that
Valentin has entered so minutely into details on this point;
there is much yet to be observed with regard to this, especially
in the dots of the spiral tubes. Valentin has also confirmed
the fact that the position of the dots on the sides of the
cells is a spiral one, a circumstance evidently connected, as I
have previously shown, with the formation of the cellular
membrane from spiral fibres; as the dots always occur
between the convolutions of those fibres running in a spiral
direction. The dotted ducts do not, according to Valen-
tin, stand perpendicular on the external layer of the cellular
partition (which is called the primary sac partition) but in a
rather slanting direction from the interior to the exterior, to-
wards the cellular partition.

Dr. Hope * read on the 21st of March 1836, a paper on
the colours of plants, before the Royal Society of Edinburgh,
which in its results bears the greatest similarity to the beauti-
ful labours of Marquart which had appeared from eight to
nine months previously. Hope in like manner shows that
two different colouring matters occur in plants, one of which
forms with acids the red colours and is called on that account
Erythrogene^ while the other gives with alkalis the yellow com-
binations of colours and is named Xanthogene. These two
substances evidently represent the Anthohyan and Anthoxanthin

* L'lmtitut, Feb. 15, 1837-
Third Series. Vol. 11. No. 69. Nov. 1837. 3 L

442 Prof. Meyen's Report on the Progress of

of Marquart. The observations of the latter on this subject
are however much more accurate than those of Dr. Hope;
Marquart showed, for instance, that the Xanthogene is pro-
duced from a blue extractive substance converted to red by
an acid, &c. It also appears from the statement of Dr. Hope
that he made no use at all of the microscope, which however
was quite necessary. One consequence of this is the retaining
of the term Ckromule, which De Candolle had proposed for
the colouring matter of plants; against the adoption of which
however many reasons exist. Dr. Hope states that he found
that the Xanthogene occurs independently of the Chlorophyll
in all green leaves; that in white flowers (about thirty different
ones were examined) Xanthogene only is contained, exactly as
in the yellow flowers, where also no Erythrogene occurs. The
explanations of this are to be found, I think, in the experi-
ments of Marquart. Red flowers on the contrary exhibited
Erythrogene, as also Xanthogene, as did blue, purple, and
orange flowers, &c.

I believe, judging from my own observations, that the work
of Marquart deserves the preference in every respect; also
that his names, on account of priority even, should be re-
tained. Marquart's memoir is not mentioned, although it
might have been well known in England*.

Hunefeld has published f a very interesting paper on the
blue colours of the flowers of plants; the subject is however
treated more in a chemical view; therefore we can only call
attention to it. Hunefeldt also proposes the use of water
acidulated with sulphuric acid, as a means of facilitating the
microscopical examination of the coloured parts of vege-
tables.

F. Schulze § has made some observations on the Amylum of
the potato, and has confirmed some of the most essential points
of the results which Fritzsche obtained in his experiments on
this subject. As such, I will mention the following: The
composition of the Amylum globule from concentric layers
deposited round a certain point, called the nucleus, and the
changes which the Amylum globule undergoes in consequence
of growth; its solution from the interior as well as at the sur-
face. Schulze directs attention to the fact, that we are ac-

* [It is to be regretted that the little encouragement given to the pub-
lication of notices of foreign discoveries in this country gives rise to fre-
quent remarks of this kind. — Edit.]

t Additions to the chemistry of vegetable colours. — Erdmann and Schweig-
ger-Seidel's Journ.fur Prakt. Chem., ix. p. 217—238. X Ibid., p, 238.

X On the Metamorphosis of Amylum. Poggendorlf's Ann., vol. xxxix.
p. 489-493.

Vegetable Physiology for the Year 1836. 44-3

quainted with no substance by which we can artificially {dis-
solve Amylum from without; and such a one must be pro-
duced in the cells of the potato in their growth.

Hartig's views * that " in the evergreen fir trees the di-
gesting apparatus itself (the leaves are understood by this)
is carried from one year to the other, and on the contrary, in
the summer-green plants, the substance for the development,"
have met with commendation from various quarters ; although
repeated observations show that the data on which that view
was founded are by no means correct. Wiegmann, sen.f se-
parated the Amylum from the wood of various trees ; to which
I will add the remark, that the occurrence of Amylum in
woods is rather an old observation. Wiegmann found, that
the powder in the end of the stem and in the root of Buxus
sempervirens was not coloured blue by iodine. Wiegmann
was not able to examine the fir trees, but is fully persuaded
that they would be quite destitute of starch; evidently, how-
ever, only because the hypothesis of Hartig is founded on
this. I find on the contrary in young fir trees, in Pinus as
well as in Abies and in Larix proportionally quite as much
Amylum as in many deciduous trees.

Creuzburgj has published some microscopical experiments
on the globules of starch before and after vinous fermentation,
the results of which are represented in a plate drawn by
Corda.

Various discoveries have been published during last year
on the occurrence of crystals in plants. Link very justly ob-
serves §, that crystals in plants might be compared with stones
and concretions in animals. They are so frequent that it
seems unimportant to mention all such cases. Link also con-
firms the observation that the spicular crystals seem to occur
more in the Monocotyledons, the conglomerate ones on the
contrary more in the Dicotyledons. Link however observes,
that these crystals occur not only in the cells, but also between
them ; an opinion to which I am able to oppose at present,
direct observations. In the tissue of Agaves and of Pontederia
cor data I thought that I had observed j| with certainty the
occurrence of some large crystals between the cells; but on
separating these crystals by macerating the tissue and by
using a higher magnifying power, I recently succeeded in ob-

• Meyen's Year's Report for 1835, p. 37-

t Flora 1836, p. 24, &c.

% Additional Notices on the vinous Fermentation of amylaceous Sub-
stances. Erdmann and Schweigger-Seidel's Journ. f. Praht. Chan., ix. p.
299, &c.

§ Element., p. 137. |] Meyen's Year's Report for 1835, p. 131.

3 L2

444 Prof. Meyen's Report of the Progress of

serving that in these cases also the crystals, occurring singly*
are surrounded with a cellular membrane.

Turpin* has made an interesting discovery with reference
to the occurrence of acicular crystals in the tissue of the
Aroidece. It is true that long ago it was known that these
crystals, as well as entire druses of small crystals, occurred in
the cells of the Aroidece ; but in the leaves of Caladium escu-
lefitum, these spicular or needle-form crystals, which here, a.v
in all other cases, always occur in the form of fascicles, are
not only very long and of extreme tenuity, but the cells also
in which they are found differ in many respects from the other
cells of the leaves of this plant. These crystalliferous cells
are those which Turpin has named Biforines; and, for reasons
which will now be stated, the position of these long crystal-
liferous cells in the leaves of the plant above-mentioned was
not perceived by Turpin ; and it is this very circumstance
which, in some respects, assists in explaining this discovery
which Turpin has made with regard to them. These cells are
several times larger than the surrounding ones of the diachyma
of the leaves of Caladium, which are filled with green-coloured
cellular sap-globules; and they are so placed that their middle
parts only lie between the cells of the partitions which separate
from each other the air-passages, with which these leaves imme*
diately below the epidermis are filled ; they protrude, there-
fore, with one end into one air-cavity, with the other end into
the neighbouring air-cavity. The membrane forming these
cells is considerably thicker than the surrounding green cells
of diachyma; they also exhibit a brownish yellow colouring.
If we now immerse these cells with their bundles of crystals
in water, most of them open at both ends, and the crystals
gradually more or less rapidly come out at the apertures,
either through one aperture, generally, however, through both.
Turpin has figured these apertures of the cells with excessive
regularity, so that one would imagine that he perceived some
entirely peculiar formation in these cells; however, even with
the highest magnifying powers, I have never been able to ob-
serve these apertures trimmed thus regular, and, as it were,
edged with broad borders; but the drawing which Turpin has
given, (rig. 4. pi. iv.), as regards the structure of the ends of
these cells, before their bursting, I find to be drawn quite
after nature. The cause of the bursting of these crystal-
liferous cells exists in the hygrometrical condition of the sub-
stance which occurs with the crystals in these cells; it is a

* Observations sur les Biforines, organes nonveaux situes entre les vesicules
du Ussu cclhdairc des feuiltes dans un certain iwmbre d'especes vegetates ap.
jpartcnant dlafamiUe des'Aroidecs. — Ann. des Sciences, Nat, 1836. ii. p. 4, 27.

Vegetable Physiology for the Year 1836. 445

yellowish gum, which in the beginning fills the entire cell; subse-
quently however, it is generally deposited only round the bundle
of crystals, giving it a yellow colour. I could observe nothing,
however, of an intestinal canal-like organ, which these crystals
are said to contain*, and which is extended at full length, as it
were from aperture to aperture, in the interior of these cells ;
but they had the appearance common to other cells containing
such bundles of acicular crystals; only in this case thicker
and yellow partitions occur where these cells protrude into
the air-cavities. Besides the yellow gummy substance, there
often occurs a greater or less number of very small molecules
in these cells, arranged laterally from the bundle of crystals ;
and these also pass through the apertures of the cell when it
bursts by the entrance of water. This bursting of these cells
undoubtedly belongs to the most interesting observations for
which science is indebted to Turpin ; but to load these cells
with peculiar names would not be allowed on a general con-
sideration of the subject. In the diagonal sides of the air pas-
sages in Pontederia cordata, the occurrence of cells with spi-
cular crystals is quite of the same kind as those in the leaves
of the Aro'idece\ and we there also find similar single cells,
containing a yellowish gum-resinous substance; and indeed
sometimes with, but in general without crystals f.

We are also indebted to Unger for an extended notice % on
the occurrence of carbonate of lime upon the surface of Saxi-
frage leaves. It has already been known for a long series of
years, that the gray and white efflorescence which occurs on
the upper surface of the leaves of various species of Saxifraga
consists of carbonate of lime ; this calcareous covering is espe-
cially found in great quantities on those very species of this
genus the leaves of which have at their borders small basin-
like depressions, as, for instance, Saxifraga Aizoon, S. ccesia,
mtacta, oppositifolia, &c. Unger explains this appearance of
lime on the leaves of the Saxifrage as an excretion ; and those
cavities which are filled with this excretion are regarded as
the excretory organs. " The epidermis of the leaves," says
Unger, " which otherwise consists of very thick-sided cells
with stripes and elevated points, becomes more delicate at the
place where they cover the secreting cavities ; and the cellular
tissue situated under these, a continuation of the fasciculi of
vessels (?), is also rather extended in length, and composed of
smaller cells which are never filled with vesicles of Chloro-

*[...." einem darmartigen Organe, welches die Krystalle enthalten? he]
f Vide the figures on this subject in Meyen's Phytotomie, tab. v.
X On the influence of the soil on the diffusion of Plants, &c. Vienna,

1836. p. 179-

44?5 Mr. R. Acklams on the Action of

phyll. The carbonate of lime is secreted through these
cavities in greater quantities the richer the soil is in lime.
We also, however, find the leaves of the above-mentioned
species of Saxifragcc very thickly covered with lime, when they
have become old, in a soil very rich in humus. It may also
frequently be observed, that many other places on the upper
surface of the leaves of those plants, besides the cavities, are
covered with a thin crust of chalk ; that the deposition therefore
of this calcareous substance does not take place through the ca-
vities only. Unger, it is true, says, " We should in this case be
mistaken if we were to consider the calcareous excretion as a
product of the entire epidermis. I myself, however, think that
this is the case; and it is easily observable on many garden
plants of this tribe. These excretory organs on the upper
side of the leaves, are said to be represented by an immense
number of pores on the under surface, as if the increased
process of secretion on the one side had produced an antago-
nistic process on the other side, but different in quality." In
fact, this deposit of lime upon the leaves of Saxifrages is an en-
tirely peculiar phenomenon, and can be connected with a few
others only; it cannot even be viewed as parallel with the incrus-
tation of the Chares, for in these the lime appears to be precipi-
tated from the surrounding water, as the carbonic acid, which
held it in solution, is imbibed by the plant. In the Saxifrages
only an exuding of the calcareous fluid seems to take place, and
this is strongest in those cavities where the cellular tissue is
very delicate : the phenomenon may be classed with the de-
position of lime in the air-cavities of the leaves of Lathrcea>
and with the occurrence of crystalline druses on the sides of
the air-ducts in Myriophyllum. We also often find in other
plants a secretion of a salt which is contained in the soil on the
surface of the leaves, &c*

[To be continued.]

LVII1. On the Action of Cold Ah' in maintaining Heat. By
Robert Addams, Esq., Lecturer on Natural Philosophy, fyc.

To Richard Phillips, Esq.
Dear Sir,

IN the last Number of the Philosophical Magazine, p. 407,
there is an account of the "Action of Cold Air in main-
taining Heat." I conclude, from the initials R. P. being an-
nexed, that you are the author of that communication ; I there-
fore suppose you will be the more immediately interested in

* Who first called attention to the occurrence of lime, on the leaves of
Saxifrages ?

Cold Air in maintaining Heat. 447

knowing what I have seen and done in regard to the heating
effects of currents of cold air on iron ; and consequently I beg
permission to acquaint you with the particulars ; and if you
think they are of sufficient interest to occupy a place in the
forthcoming Number of the Philosophical Magazine, perhaps
Tou will oblige me by forwarding the same for publication.

I was at Sheffield in last December, and then a Mr. Linley,
jellows-maker of that town, showed me the following curious
xperiments : first, a rod of iron, about an inch in diameter,
vas heated at one end in a forge fire, up to a full white heat,
-hen quickly withdrawn from the fire and exposed to a strong
blast of cold air from a forge bellows ; the iron immediately be-
came so hot as to fuse, and the liquefied matter was blown off
and burnt in the air with the scintillating appearance of iron
wire burning in oxygen gas; and so continued to melt until a
pound or more of the metal had been thus wasted.

Another mode of producing the same action consisted in
heating a rod of iron, as before; but instead of a blast of air,
it was tied to a cord, and by it whirled round in a vertical
plane; thus by passing swiftly through the cold air it melted,
and was thrown off in beautiful scintillations, appearing as
luminous tangents to the circle in which the bar was moved.

I have since applied a heated bar of iron to the periphery
of a revolving wheel, and by an including tin hoop or guard,
it is thus made an interesting class experiment.

The cause of this augmentation of temperature is, I con-
ceive, referable to the oxidation of the metal, which takes
place freely under the conditions of the experiments here re-
corded. Then, as is well known, the formation of the oxide
is accompanied with a great development of heat; and the
cases before us are striking examples of the heating influence
by chemical action predominating over the cooling effect of
the air conjoined with the radiating force.

The success of these experiments chiefly depends upon
having the iron at first of a sufficiently high temperature, and
upon the velocity of the air from the bellows, or otherwise the
velocity of the iron through the air. For the iron at a white
heat is greedy of oxygen, which the air solidifies. Then the
oxide thus formed requires to be blown or whirled off, in order
that fresh surfaces of the metal may be exposed to the air.

When the blast is employed, we see the oxide fusing, and
deep channels scooped out in the bar by the rushing air on
that side where the current is directed.

I am, dear Sir, yours truly,

Robert Addams.

Kensington, Oct. 16th, 1837.

T

[ 448 ]

LIX. Notice of New Discoveries of Ehrenberg* s respecting the
Bacillaria?.* By M. Wiegmann.

'HE readers of this Journal will have seen from Meyen's
Report on Botany, (Phil. Mag., present volume, p. 385—
390.) that the microscopical animal forms of this family continue
yet to be a subject of dispute, inasmuch as they are referred by
several botanists to the vegetable kingdom. Meyen is also of
this opinion, which seemed to be supported by the circum-
stance that these creatures had hitherto not been observed to
take in any coloured nutritive substance, like the other Infu-
soria. Recently, however, Ehrenberg has succeeded in feed-
ing various species belonging to the genera Navicular Gom-
pho?iema9 Arthrodcsmus (Scenodesmus Meyen), Closterium ace-
rosum, on which subject he read a paper, at the same time ex-
hibiting specimens in proof of this, before the Society of Na-
turforschende Freunde at Berlin. Vesicular ventral sacs, per-
fectly similar to those of the other polygastrical Infusoria, were
apparent. " I could count," says Wiegmann, " with the
greatest distinctness from six to seven ventral sacs completely
filled with blue colouring matter, in the clear middle part of
a Navicula gracilis exhibited by Ehrenberg." With this dis-
covery, therefore, the most perfect proof has been afforded of
their coincidence with the Polygastrica, which, however, the
peculiar gliding motion f which was perceptible in many of
them had before sufficiently indicated ; which motion may
be plainly recognised in many of them, and cannot be com-
pared either with the lively motions of the sporules of Alga?,
or with the motions of the Oscillatoria. The foot-like papilla?
which these animalcules protrude out of various apertures, and
drawback, may also be remarked in many of them: for in-
stance, in Navicida very easily, when the water is rather thick ;
we can also perceive with the greatest facility the above-men-
tioned apertures in the empty shields J of the fossil Infusoria.

* From Wiegmann's Jrchiv, 1837, part iv., p. 377- Translated by
Mr. W. Francis.

f [I have also lately noticed, in a few species belonging to this family,
the peculiar papillae by which they creep along. I may here state that I
have often seen various species of Bacillaria and Navicula not only push
one another out of the field, but have remarked that they make room for
each other, which certainly cannot be attributed to electricity, as Morren
supposes, (Phil. Ma^„ p. 389.)— W. F.]

\ See Ehrenberg s paper in the Scientific Memoirs, vol. i. p. 405.

[ 449 ]

LX. Meteorological Observations taken at Bermuda, in
July, August, and September, 1836; and on Sept. c2\st, 1836,
in accordance with the suggestions of Sir John Herschel*.

Place of observation sixty feet above the level of the sea.
July. Barometer.

Hours of Ob-

Inches.

No. of Ob-

servation.

servations.

8 A.M.

30-149

26

9 —

30165

28

Noon

30-135

6

2 P.M.

30-164

11

3 —

30-182

18

4 —

30151

22

9 -

30183

24

Mean height for the month,
taken by collecting those of the
8 A.M. and 9 A.M., with those
of the 3 and 4 P.M. = 30-1615.
Corrected by capillary action, ca-
pacity, and reduced from 77i°
to zero.

Greatest, 30-376 inch. Lowest height 29*620 inch. Os-
cillation, '756.

Mem. On the 25th the barometer was at 30-376, whence
to 31st it gradually fell ; at 1 £ A.M. of this day it descended
to 29-620. On the 30th and 31st a very heavy storm with
rain.

Mean temperature of the month, 75-79°. Greatest heat,
80°; least 67°. Mean temperature of 30th and 31st, 79°.
Maximum taken from the shade, free from current and re-
flection ; minimum from a register thermometer out of door.

Mean dew point, 74°.

Windy from the western side of the compass twenty-four
days, of which fifteen were S. W. — Wind from the 30th S.E.,
changing from the 31st to W.S.W.

Greatest heat from 3 to 4 p. m. — Blackened bulb exposed
to the sun, mean of six clear days, taken at the greatest heat,
96°.

Bulb lightly covered with calcareous soil, 138°.

Rain in seven days. Lightning eight days, mostly distant
and in the east. Thunder less frequent.

* Communicated by Dr. Dalton, by whom they have been arranged
from the original observations of Lieut.-Col. Emmett, R.E. We have since
received observations for the entire year from July 1, 1836, to June 30,
1837, from Lieut.-Col. Emmett, which we shall insert in our next ; but we
retain the present article on account of its having been prepared by Dr.
Dalton.

Third Series. Vol. 11. No. 69. Nov. 1837.

3M

450

Meteorological Observations

August. Barometer.

Hours of Ob-

Inches.

No. of Ob-

servation.

servations.

8 A.M.

30126

29

9 —

30131

28

Noon.

30-159

14

2 P.M.

30-108

10

3 —

30-112

20

4 —

30109

20

9 —

30-135

25

Mean height taken asl ,niln
before JdU-iU

Corrected as before, \ «n a^
and reduced for 77i° ... /

Greatest height, 30-388 ; Least, 29*860. Oscillation, -478.

On the 18th, storm with rain. S.W. wind. Lightning.
Mean temperature of the month, 76°*65. Greatest heat
was on the 1st at 4 p.m., 80°'4 ; least heat, night of 13th and
14th, 70°.

Mean dew point, 72°*5 ; many observations at 2 p.m. Tem-
perature of the sea, 82°.

Rain on twenty-two days ; quantity, 9*24 inches. Lightning,
eleven days, nine of which in the east. Thunder, four times.

Winds, twenty-two on the western side of the compass,
thirteen of which were S.W.

Morning of the 21st very stormy, but the barometer did
not fall below 30*114. Dew point at 9 a.m., 75°. Tempe-
rature, 79°.

September. Barometer.

Hours of Ob-

Inches.

No. of Ob-

servation.

servations.

8 A.M.

30154

27

9 —

30-166

27

Noon.

30150

15

2 P.M.

30-148

18

3 —

30-129

18

4 —

30128

21

9 —

30-154

23

Mid.

30-164

10

Mean height taken as"! 00.144

before J

Corrected as before, 1 «jn.n-o

and reduced to zero J

Greatest height 30-316

(South-east.)

Least 29 936

(Strong N. East.)

Oscillation -380

Mean temperature of the month, 760,75. Greatest heat,
81°; least heat in two nights, 71°. Mean dew point, 69^°.

Winds, twenty-one days from the eastern side of the com-
pass, and but seven from the western.

Rain on five days; quantity, *91 cubic inch.

Lightning six times ; twice only with thunder.

Temperature of the sea, 80 J°, and towards the close of the
month, 78£°.

made at Bermuda in 1836.

451

Summary of the Observations of the Quarter ending
the 30th of September.

Baro-
meter.

8 A.M.

9

Noon.

2 P.M.

3 P.M.

4 P.M.

9 P.M.

Midnight.

No. of
Obs.

1 82

83

35

39

56

63

72

17

July.
Aug.
Sept.

30-165
30126
30-154

30-165
30131
30166

30-135
30159
30150

30164
30-108
30141

30-180
30112
30129

30151
30109
30128

30-183
30135
30-154

30117
30104
30-161

Mean

30143

30-154

30148

30-138

30141

30-129

30-157

30127

f30-090

Mean height corrected < 30*042

[30-070

Greatest height . .
Least

30-067 at sixty
above the sea.

. 30'388
. 29-620

feet

Greatest Oscillation

•768

Mean temperature, 76°*73, about 2° lower than 1835 ac-
cording to reports. Rain in thirty-four days; quantity in
August and September, 10*15 inches.

Windy fifty-three days from the western side of the com-
pass. Greatest heat in July and part of August, about 4 p.m. ;
afterwards somewhat below that time.

Dew point generally highest about 3 p.m. to 4.

Barometer used, Neuman's portable, with iron cistern ; the
attached thermometer being in the mercury.

Thermometer made also by Neuman; one brought as a
standard. Dew point taken by using a cooling mixture in a
copper gilt cup. Winds taken at sunrise, noon, and sunset,
from the signal stations ; these very variable, changing often
from 9 to 11 a.m.

Observations on the 21 st of September, 1836, with reference to
the suggestion of Sir John Herschel.

Bar.

Attached Unattached

Wet

Dew

Therm. Therm.

Bulb.

Point.

20th Sept.

o o

18 hour ....

.. 30194 .

765 76-5

20 - ...

.. 30-196 .

idem 77 • •

.... 72*

21 — ...

.. 30 200 .

idem 77*5

22 — ....

.. 30208 .

.... 77 78| ..

... 73*

Noon

.. 30206 .

.... 77*5 795 ..

3M 2

.... id. .

69

452

Mr. E. Solly on the Palo de Vaca

Bar.

Attached Unattached Wet

Dew

Therm. Therm. Bulb.

Point.

21st Sept.

2P.M-

. 30-182

78 80-5

74*

70°

4 —

. 30 174

id 79-75

73*

6 —

. 30- 174

id 77*71

72*

67*°

8 —

. 30-196

id 77

72

9 —

. 30-194

id 76-75

72

Midn

. 30-184

77*5 7025

66?

None made until 6 A.M. (18), probably little variation.

18 hours ....

. 30- 182

775 76

71

20 —

. 30- 194

id 77-5

73

22 —

. 30204

78 79-5

74

Noon

. 30-194

78* 80*

id.

22nd Sept.

2 —

. 30- 162

79 81

74|

4 —

. 30-150

79* 80-5

74*

6 —

. 30158

79 78

72*

Wind 20th, 18 hours,

North, light, and clear

Ditto Noon,

North-west.

Passing

Wind 21st, 6 hours,

Ditto, bright and clear.

and other

Ditto 18

—

North, ditto ditto.

clouds,

Ditto Noon,

North-west, hot sun.

cirrhi and

Wind 22nd, 6

hours,

North-east, bright and

cumuli.

clear.

No correction made for barometers. Heat of white bulb,

89°. Temperature of the sea, 79°.
the sea, 78°*.

Jug. 9th, 1837.

Temperature of air over

LXI. On the Palo de Vaca or Cow Tree of South America.
By Edward Solly, Jun., Esq.

I AM indebted to the kindness of Dr. Lindley for specimens
of the bark, sap, &c, of the Galactodendimm utile, or
Cow tree of Humboldt, accompanied by a highly interesting
letter from Sir R. K. Porter to the Hon. W. F. Strangways,
and communicated by him to Dr. Lindley; from which the
following are extracts.

Dated " Caracas, June 8th, 1837.

" Towards the close of last month, I started from hence
across the mountains, in a north-west direction towards the
coast ; and a most fatiguing and not a little dangerous jour-
ney we had ; for journeying out of the beaten paths (for good

* An abstract of Lieutenant Nelom's observations on the geological con-
stitution of Bermuda will be found in Lond. and Edinb. Phil. Mag.,
vol. v. p. 222 ; and some remarks on the same subject by Mr. Greenough,
in vol. vii. p. 147. — Edit.

or Coxv Tree of South America. 453

roads we have none), it becomes break-neck work. Fifty
miles of travel brought us to an elevated valley called Catorori,
about a couple of miles from a mountain-perched respectable
town called Cariacco ; at a small sugar estate in the above-
named valley we halted, as from it some four miles higher up
in these elevated regions, grew the object of our search. On
inquiry we learnt that it would not be possible to go there
otherwise than on foot; therefore at six the next morning we
started, accompanied by a few Indians and coloured peasants.
I need not trouble you with the difficulties we encountered
ere we had achieved our long league of fatiguing ascent
through a dense forest, obliged at almost every step to have
the way hewn out for us, so thick and interlaced were the
branches, jungle, and pendent bejucos. A couple of hours'
toil placed us at the foot of one of the trees in question, which
very far exceeded any idea I could have formed of it from all
the descriptions given to me, or even from that of Humboldt.
This marvellously colossal vegetable cow stood surrounded
by thousands of other trees of different characters, few of them
less wonderfully stupendous than itself. At about five feet
from its roots it measured in circumference somewhat more
than twenty feet. Its trunk rose from its enrooted base most
majestically straight for full sixty feet (gradually decreasing
in thickness), clear of the slightest interruption, either of leaf
or branch. At this vast elevation the huge and powerful
branches spread forth on all sides to an extent of perhaps
twenty-five feet from the centre stem ; thickly and luxuriantly
clothed with immense leaves of a brilliant though sombre
green, not unlike in colour, polish, and shape, to the laurel,
but somewhat more pointed, each being from twelve to six-
teen inches in length, and from three to four in width. This
magnificent verdant portion of the tree I should estimate to
be not less than forty additional feet, hence the whole taken
together amounted to no less than 100 feet ; but others a few
hundred yards from us I found even exceeded this, both in
height and thickness, by many feet.

" As soon as an arrow-shaped incision was made deep in
the bark (even to the wood itself) the snowy stream burst
forth in a most extraordinary manner ; so unceasing was the
current, that within a quarter of an hour we filled one bottle,
and the like was effected in the same time at another tree. In
colour and consistence at the time it was drawn, it differed in
no degree from that of the cow ; in taste, not less sweet and
palatable : however, it left on the tongue a slight bitterness,
and on the lips a disagreeable clamminess. * * *

" The bark is a little roughish, and in general hue of a

454 Mr. E. Solly on the Palo de Vaca

pale yellowish olive green ; beneath the outer skin is a crust
of more than an inch and a half in thickness, of a deep chest-
nut colour, wherein seemed to be contained the lacteal fluid,
for on detaching it from the body of the tree, the milk oozed
through thousands of pores from the curved surface that had
embraced the trunk. The wood itself is white, close-grained,
and hard, resembling in every way the box wood of Europe.

" I could not learn the precise period when the Palo de
Vaca flowers (if ever) or bears its fruit. Plants, (and many
are growing all about the trees,) will not live by even transport-
ing to Caracas. The temperature of the air at 8 o'clock a.m.
whilst at the foot of the tree, was 70° of Fahrenheit's scale*."

The milk as I received it was evidently rather altered by
time ; it was of the colour and consistence of very rich
cream, having a sour and rather unpleasant odour, and a nau-
seous and acescent taste, accompanied by a somewhat gritty
feel on the tongue. When left undisturbed for some time in
a close bottle, a slight separation took place, a small quantity
of a pale yellow fluid sinking to the bottom. The specific
gravity of the sap was 1*085 at 60° Fahrenheit.

Exposed to the air, the sap gradually contracted from the
evaporation of water, &c, and finally left a grey, transparent,
and very viscid mass. When a portion of the sap was poured
into water, it did not spontaneously mix, but fell to the bot-
tom as a bulky white precipitate; on agitation, however, it
easily mixed with the water, though after some hours' standing
a slight coagulum rose to the top. When boiled, the mix-
ture was immediately coagulated ; this was not effected either
by acids or alkalies.

When the sap was distilled at a low heat, water holding
in solution acetic acid passed over, and a grey transparent
mass remained, similar to that left by the evaporation of the
sap exposed to the air ; when the heat was cautiously raised,
the mass fused, became of a pale yellow colour resembling oil,
and contained numerous dark flocks of an infusible substance
floating in it; 100 grains of the sap yielded on the average
38*0 grains of solid residue. In order to determine the na-
ture of this residue, it was repeatedly digested in cold aether,

• This tree was first described by Alexander Humboldt in his Relat.
Hist., t. ii. p. 106, 130. See also Ann. de Chim. et de Phys. t. vii. p. 182.
It received the name Galactodendrum from Kunth, who imagined it to
belong to a new genus ; Synopsis Plantarum, t. iv. p. 198. I am only aware
of two detailed chemical examinations of the sap, one by Boussingault and
Rivero, Ann. de Chim. et de Phys., t. xxiii. p. 219; the other bv Dr. T.
Thomson, Trans, of the Royal Society of Edin., 1829. — E. S. [See Lond.
and Edinb. Phil. Mag., vol. vii., p. 501.— Edit.]

or Cow Tree of South America, 455

which, from previous experiments, I had ascertained would
dissolve the waxy principle, or galactin. By this process
30*57 grains of galactin were dissolved, leaving a brown pow-
der weighing 7*43 grains.

Cold water was poured on this residue, and dissolved 4*37
grains, yielding a solution precipitated by alcohol, becoming
viscid when evaporated, and having hardly any taste ; what
little it had was derived from traces of saline matters: it was
evidently gummy matter coloured slightly by extractive. The
residue, weighing 3*06 grains, was boiled in alcohol ; the solu-
tion gave a precipitate with perchloride of mercury and with
galls; this agrees entirely with the characters of gluten.
There yet remained a small quantity of a brown powder, which
was easily soluble in a weak solution of caustic potassa; this
proved to be vegetable albumen. It is very probable that in
the sap, these two last- mentioned substances were held in so-
lution by acetic acid, and that they were precipitated on its
evaporation. From these experiments the sap appears to
contain

1. Water and acetic acid 62*00

2. Galactin 30*57

3. Gum and saline matter,
bably acetate of magnesia

4. Gluten and albumen 3*06

™> Pro-\ 4*37
>ia J

100*00
When the aethereal solution of galactin was evaporated, and
the residue carefully fused to expel all adhering aether, pure
galactin was obtained ; its properties were as follows. It was
transparent, and of a pale yellow colour ; tough, adhering
strongly to the ringers, and drawing out between them into
threads, having a shining pearly lustre ; but at low tempera-
tures it became hard and brittle. It was fusible between 120°
and 130° Fahrenheit; when exposed to a heat of above 500°,
it boiled and was entirely volatilized, but I rather believe a
portion was decomposed, giving rise to the formation of a
highly combustible fluid; it was combustible like wax, burning
with a bright smoky flame. On the surface of boiling water
it floated like an oil, and was not sensibly altered, but a por-
tion was carried up in vapour with the steam ; when, how-
ever, the galactin was not perfectly dry, or contained any
moisture, it rendered the water turbid from the mechanical
suspension of small particles throughout it. It was not sa-
ponifiable by potassa or by ammonia ; when not dry, however,
it frothed up, and seemed to combine with a boiling solution
of potassa; on cooling, it separated unaltered. It was soluble

456 Mr. Horner's new Demonstration of an

in cold alcohol, more easily in cold aether, and still more so
in either of them when hot; from its alcoholic solution it was
precipitated in white flakes by water ; this was a mechanical
mixture of galactin and water. It dissolved in sulphuric acid,
and when heated caused its decomposition.

The action of nitric acid on galactin was very remarkable ;
at common temperatures it did not immediately act on it, but
when left for some days it converted it into an opake, yellow,
friable mass ; this same substance was obtained more rapidly
when the acid was heated, effervescence ensued, and on dilu-
tion, a pale yellow precipitate fell. This substance resembled
a resin : it was fusible, combustible, soluble in aether, brittle,
and friable; it had a resinous odour, and was insoluble in hot
or cold water : during this action no oxalic acid was formed.

Galactin resembles wax in being fusible, volatile, combus-
tible, and insoluble in water, but it differs in the following
effects of reagents.

Action of On wax On galactin.

Cold sulphuric acid none dissolves it.

Hot ditto combines with decomposed by.

Nitric acid forms oxalic acid forms no oxalic acid.

Alkalies saponify no action.

Cold alcohol no action dissolves it.

Cold aether no action dissolves it.

LXII. New Demonstration of an original Proposition in the
Theory of Numbers. By W. G. Horner, Esq.

To Richard Phillips, Esq., F.R.S., L. $ E.9 $c.

My dear Sir,

I WILL not trouble you with an array of corollaries and
practical deductions, for which I hope to find a fitting
place elsewhere, but trust that you will regard the succinct
statement which I send as not unsuitable to the purposes of
your Magazine. I am, yours very sincerely,

W. G. Horner.

" If c is a prime number, and N any number not divisible
by c, the quantity Nc_1 — 1 will be divisible by c, so that

1ST-1-!

will be an integer."

c

This theorem, which is due to Fermet, is justly described
by Legendre as " one of the most important in the theory of

original Proposition in the Theory of Numbers. 457

numbers." He assumes it as the basis upon which his own
theorems respecting prime numbers are founded, and to which,
of consequence, the disquisitions of Gauss are equally to be
referred.

Euler's demonstration, which has been generally adopted
by other writers, is exceedingly simple and convincing, but
does not appear capable of being extended to meet the case
of composite divisors, without a very complicated and operose
process. Such a process is sketched in the concluding para-
graph of Part IV. chap. ii. of Legendre's Theorie ; but the
writer does not appear to have actually gone through it, nor
am I aware that any one else has.

A different demonstration, not less simple, was given by
Mr. Ivory in Leybourn's Repository; and being engaged at
the time in a research, which caused the want of a more en-
larged theorem to be urgently felt, I was glad to perceive thai
the new demonstration was more tractable than Euler's, and
might easily be made to include the general case. The result
of my attempt is given in the Annals of Philosophy for Fe-
bruary 1826.

The mode of demonstration, however, is little less artificial
than that of Euler, and did not supply a ready transit to the
distinct cases which occur in its practical application. But by
closely observing the indications which arise in actual prac-
tice, I soon afterwards found myself in the track of a demon-
stration of the most satisfactory description ; simple, convin-
cing, and naturally adapting itself to all the requisite practical
uses. It is this which I now wish to submit to mathemati-
cians ; and I trust that the Theorem itself, which is here
proved, will not be regarded as a mere extension of Fermat's,
but recognised as the primordial idea from which his disco-
very was a fragment fortuitously detached.

Theorem. — If N, P, are prime to each other and c in-
dicates the number of integers less than P and prime to it,

Nc— 1 •

* i is an integer.

Ntt-R
Dem. 1. — Let us consider the general formula

P

an integer; where Ra is the remainder left after dividing

NMby P: — R is prime to P ; for had they a common factor,
it would divide IP+Ra, that is N"; and so P and N" would
have a common factor ; which is against the hypothesis
(A). Hence RM is an integer ^P, and prime to it.

Third Series. Vol. 1 1. No. 69. Nov. 1837. 3 N

458 Mr. Horner's new Demonstration, fyc.

2. As this class of integers is limited, it is obvious that in
assigning to u the successive values 0, 1, 2, 3, to an in-
definite extent, the same values of R will repeatedly occur.

N" — R NM+* — R
Assume, therefore, R , = R ; then " and t

' u+z u ■ p p

being integers, their difference p *~ ls a^so integra^

Therefore - is integral ; since P and NM are incommen-
surable.

S. We will suppose d to represent the least value of z, which
satisfies this condition. Then it will also represent the least
interval of recurrence of the same remainder. For if the equa-
tion R"=R , were possible with bZd, we should have

N" — R N"+6— R

2 " and !f integral ; and therefore their differ-

P P &

N"(N6 — 1) N*~ 1

ence ^-p- -; and consequently — p — integral, with

bz.d; which is against the hypothesis.

(B.) It follows from this that the series of remainders Rl9

R25 R31 (Ra = )l recur perpetually in the same order, and

are all distinct from each other.

4. If a=c9 the proof is complete ; for by (A) it cannot ex-
ceed e. But if aZ.C) let q be any one of the remaining c— a
integers, which are less than P and prime to it ; and let

" be integral. But * Z—l is also integral. Where-
fore their difference u " is integral; or ^Rm is =QW

rejecting the P's.

5. Now the same reasoning as was employed in Step (1),
will prove that Qw is of the class (A). But it is not found in
the series (B). For, imagine it to be =RJ;; then qRu=zR ;

whence * u is integral. From it deduct q times the in-

NM— R NM (Wu— o)
teger J, The remainder is * — p *£ integral ;

y^V — U

whence S is integral; or <?= &'_„ a term °*" s?r*es (B).

Obituary Notice of Mr. Horner. 459

Which is against the hypothesis (4).

6. As at step (3), it may be shown that Qm = Qu is im-
possible, ifb^a.

(C.) Hence the series of remainders Qp Q2, Q3,

(Qa = ) q9 recur perpetually in the same order, and are all

distinct from each other, and from the terms of series (B).

7. Should any term of (A) yet remain, a continuation of

c
this process (4) will exhaust them. For, that — is integral

may be ascertained by reflecting that every unanticipated as-
sumption, such as q, entails a> terms such as series (C), all un-
anticipated.

8. But since — -II- is integral, and ~ m is also integral,
_ £ is integral ; that is _ .. q.e.d.

#*# Since this paper was received we were pained to learn
that its distinguished author is no more. We have been
favoured by a mathematical friend with the following notice
of his decease and his character. " Mr. Horner died on the
21st of Sept. after a week of extreme suffering, arising from a
complication of asthma and ossification of the heart, aged
fifty-one. His health had been for many years in a very pre-
carious state, and his sufferings (as in this class of disorders
they almost always are) often very great ; yet his equanimity
and firmness of character were fully equal to cope with pain
and bodily decay; and his end was such as a Christian's should
be — calm, peaceful, happy.

" As a mathematician Mr. Horner was undoubtedly amongst
the first men of our time. His method of continuous approxi-
mation to the roots of equations of all kinds, but which has
hitherto been little applied except to algebraical equations, is
probably the most important invention with which algebra has
been enriched during the last two centuries. The Philoso-
phical Magazine contains a considerable number of his papers
on mathematical and physical subjects, which are of course
well known to its readers, and which, therefore, we need not
specify or eulogise. Some alterations in this paper were sent
off' only a few days before his lamented decease.

" Mr. Horner was not a mathematician only, he was a man
of the most refined taste in literature, both classical and ge-
neral. He has left behind him many papers on these sub-
jects, on biblical criticism, and on other subjects, as well as on

3 N 2

460 Rev. N. S. Heineken on the Galvanic Shock- Multiplier.

mathematics. His poetic compositions are full of taste and
feeling ; and his Latin compositions are remarkable for ele-
gance and purity. In this respect, indeed, he combined
qualities, powers and taste which are scarcely recorded to
have been coexistent with his high mathematical faculties, in
any other man."

LXIII. Description of the Galvanic Shock- Multiplier. By the

Rev. N. S. Heineken.*
HPHE drawing represents an apparatus for producing a
-■■ rapid succession of shocks when used with the galvanic
pile or battery, and may be called the Galvanic Shock-Multi-
plier. The idea was derived from the revolving armature of
the magnetic battery ; but I am not aware that anything of the
same kind has been applied to the ordinary galvanic battery.

Description.
A is a thin wheel of copper having four or more circular
indentations at equal distances
in its circumference. It is fasten-
ed by a nut at B to a spindle
which passes through the brass
tube C, and has at its other end
a pulley D. The tube is insu-
lated by means of the glass pil-
lar E F fixed into the wooden
support F G, and by this at-
tached to the base. H a wheel
by turning which the pulley D
and disc A revolve. I K two
brass arms attached by mount-
ings to glass tubes at L and M,
and by them insulated and fixed
also to C E. These two brass
arms hold the copper wires N O
by means of the screws P P. The wire N has its end formed
into a slight spring; so also has O. That at N touches the
copper disc A only where the circumference is entire ; that at
O always presses lightly on the face of the disc. The mode
of operation of the apparatus will be sufficiently obvious. If a
wire having a moist sponge be attached to one extremity while
the other is connected with one of the poles of a battery, and
the hand grasp the moist sponge, and if the other pole of the
battery be connected by a wire with N, the other hand grasping

* Communicated by the Author.

Mr. Sylvester on the Optical Theory of Crystals. 461

a second sponge, and connected with the wire O, a rapid suc-
cession of shocks will of course be experienced during the re-
volution of the disc A, in consequence of the interruptions
which are occasioned in the circuit by the indentations in its
circumference. The application of the instrument in various
experiments, particularly those on the dead body, will be
readily suggested.

I will not trespass further on your space than to state that
the figure is in size one third of that of the instrument, that
the copper disc and wires are amalgamated to ensure good
contact, and that by a little alteration the apparatus may be
employed for the rapid changing of the poles of a battery in
electro-magnetic operations.

Sidmouth, Sept. 27, 1837.

LXIV. Analytical Development of FresneVs Optical Theory of
Crystals. By J. J. Sylvester, Member of St. John's Col-
lege, Cambridge.

T^HE following is, I believe, the first successful attempt to
■*■ obtain the full development of FresnePs Theory of Crystals
by direct geometrical methods. Hitherto little has been done
beyond finding and investigating the properties of the wave
surface, a subject certainly curious and interesting, but not of
chief importance for ordinary practical purposes. Mr. Kel-
land, in a most valuable contribution to the Cambridge Philo-
sophical Transactions *,has incidentally obtained the difference
of the squares of the velocities of a plane front in terms of the
angles made by it with the optic axes. 1 have obtained each of
the velocities separately, and in a form precisely the same for
biaxal as for uniaxal crystals.

I have also assigned in my last proposition the place of the
lines of vibration in terms of the like quantities, and that in a
shape remarkably convenient for determining the plane of ^ po-
larization when the ray is given. For at first sight there ap-
pears to be some ambiguity in selecting which of the two lines
of vibration is to be chosen when the front is known. If (p) be
the perpendicular from the centre of the surface of elasticity
let fall upon the front, tt in the < es made by the front with
the optic planes, st eu the < es between its due line of vibration
and the optic axes, I have shown that

cos,, = /P-J*V«ni, cos .„ = */*!=£!. f«i»
s/ a3 — c* sin iu V a* — c* sin i,

so that all doubt is completely removed. The equation pre-
* See Lond. and Edinb. Phil. Mag., vol. x. p. 336.— Edit.

462 Mr. Sylvester's Analytical Development

paratory to obtaining the wave surface is found in prop. 6
by common algebra, without any use of the properties of
maxima and minima, and various other curious relations are
discussed.

Without the most careful attention to preserve pure sym-
metry, the expressions could never have been reduced to their
present simple forms.

Analytical reduction of FresneV s Optical Theory qfC?ystals.

Index of Contents :

In proposition l,a plane front within a crystal being given,
the two lines of vibration are investigated.

In proposition 2 it is shown that the product of the cosines
of the inclinations of one of the axes of elasticity to the two
lines of vibration, is to the same for either other axis of ela-
sticity in a constant ratio for the same crystal ; and the two
lines of vibration are proved to be perpendicular to each
other.

In proposition 3, a line of vibration being given, the front
to which it belongs is determined ; and it is proved that there
is only one such, and consequently any line of vibration has
but one other line conjugate to it.

In proposition 4, certain relations are instituted between
the positions of, and velocities due to, conjugate lines.

In proposition 5, the z_es made by the front with the planes
of elasticity are found in terms of the velocities only.

In proposition 6, the above is reversed.

In proposition 7, the position of the planes in which the two
velocities are equal (viz. the optic planes) is determined.

In proposition 8, the position of a front in respect to the
optic axes is expressed in terms of the velocities.

In proposition 9, the problem is reversed, and it is shown
that ifu v„ be the two normal velocities with which any front
can move perpendicular to itself, and i, \H the < es which it
makes with the optic planes,

then v* as a9 (sin '-^-— -* \ + c* /cos /j — )

»,;=0.(si„^)\cs(cos'4-'y.

In the 10th the <es made by a line of vibration with the
axes of elasticity is expressed in terms of the two velocities of
the front to which it belongs.

In the 1 1th proposition the velocity due to any line of vibra-

o/TresnePs Optical Theory of Crystals. 463

tion is expressed in terms of the <es which it makes with the
optic axes,

viz. v* — b2 = a2 — c% . cos e/ . cos e/t.

In the 12th proposition e, e/y are separately expressed in
terms of i, i„.

In the Appendix I have given the polar or rather radio-
angular equation to the wave surface, from which the celebrated
proposition of the ray flows as an immediate consequence.

Proposition 1.

Let Ix -f my -f n z = 0 . . . (a) be the = n to a given front
to determine the lines of vibration therein.

It is clear that if x/y/ z be any point in one of these lines, the
force acting on a particle placed there when resolved into the
plane must tend to the centre. Consequently the line of force
at x y z must meet the perpendicular drawn upon the front
from the origin. Now the = n to this perpendicular is

I m n v

And the forces acting at x y z are a2 x, W y, cq z parallel to
x y z, — so that the = n to the line of force is

X-g_Y-y_Z-«

a*x "7 b2y ~~ c*z ' l ;

f% X - a*x Y = (& - af) a: # (3.)
from (2) we obtain J c2zY - b2yZ = (> - b*) y z (4.)

La*a?Z - c2*X = (a9-c*)sa; (5.)

Hence (Z>3 — a*)xyn + (c2 - b2)yzl + (F-c^zxm

= biy<JZ-nX)+c'2z(mX- I Y) + a*x(n Y-m Z)
but by & z =ns (1) Z Z - n X = 0 m X-Z Y=0 it Y-ro Z =0

... (ja _ „•) JL + (c* - #) i. + (a2_ c«) J5. = o . (b)

Also we have nx + Ix + my = 0 , («.)

... (£* _ fl«) n* + (<J - £«) /2 + n / . (*2 - £* . i+6*-a».£-^

= a2 — c2 . ;»*

2

(^-^(-j) + ^7-{c2-62.Z2 + 6*-a2.n2-.a8-c2.w9}^

464 Mr. Sylvester's Analytical Development

. . . + b* - a2 = 0
And in like manner interchanging bty, m with r, *, n

+ c2 — tf2 = 0.
Hence if ( — — ) ( ^ """"^ ) De tne two systems of values

of i, Athene .JiZi.jfY ij-i)
^ a? \X ar, X V\X #„ X a?,,/

are the two lines of vibration required.

Proposition 2.
By last proposition it appears that

Z£* = c*~a* ...... ^ y

m§mm ft* — c2 • v •/

and^ = j^L£ w

%. y,y„ + z,z„ - g9-^3 _ _ j

#, #„ W- — c*

And .*. the two lines of vibration are perpendicular to each
other.

N.B. =ns (c) and (d) must not be overlooked.

Proposition 3.

A line of vibration is given (i. e. ^1 ~L are given ) and

the position of the front is to be determined.

Let Ix + my +'nz = Obe the front required,
then Ixt H- m yt + n n\ = 0,

and (62 - c2) — + (c2 -*j - + ^"=T2 . -,= 0.
Eliminating (w) we get

V 5 »i /

g^FresnePs Optical Theory of Crystals. 465

A % y,/

±__x, a2-b2 . y? - c2 — a2 . z*
' ™ m Vi ' b*^~? . z2 - a% - b2 • *?

*l a* • (** + y? +•*') - (gg** + ^g + c* **)

" y, " b* . (*« + y2 + */) - (««*« + Vy? + c> z*)
If now we make x,9 + yf + zf — \

*efjr b2yf + c*z? = v2

and

• '

m

-ft

a2 -
b2 -

»,2

and

in

like

manner

I
n

a2

' c2

-V2

,\ a*—vf xt . x + b2 — vj* . y, . y + c2 — v, z, . z — 0 is the
= * required.

Proposition 4.

— , — having each only one value, shows that only one

front corresponds to the given line of vibration. Let xu yn *~ vn
correspond to xt y{ zf vt for the conjugate line of vibration,
then the = n to the front may be expressed likewise by

so that

v* xu x + b2 - v2 .y,,y + c2 — v2 zu. z = o,

{p-vtfixi i&-vu*)yH (c2-V)V

Proposition 5.

To find co, cp, rj/, the < es made by the front with the planes
of elasticity in terms of vt vu.

By the last proposition
,cos .). - {a2-v2Tx* .

Now, by proposition (2), £2$ = J^2 = ~^-t

.'. (COS CO2)

(«• - tyQ (a2 - tyQ (c» - 62)

TAW Sm«. Vol. 1 1. No. 69. Not. 1837. 3 O

466 Mr. Sylvesters Analytical Development

' (a2 - &2) («2 - c2)
Similarly,

(cos*) - (F - «2) (62 - c2)
(cos*j - (c2 _ fl9) (fi9 _ £2) .

Proposition 6.
To find i?y v„ in terms of eo, <$>, v(/.
By the last proposition
(cos oo)2 a2

a*-v? " (a2 - 62) (a9 - c2) ~ V[

(cos4>)2__ #

& _ V/3 - (a2 _ £2) (a2 _ c«) %

(cos vl/)2 c*

c2 - v? - (a2 - 62) (a* - c8) *'" ; (c2 - a2) (c* - £2)

(cos co)2 (cos <$)2 (cos vj/)2 _
•'• a2 _ v 9 + j«— T^ + C2 _ ^2 - °>

Just in the same way

(cos eo)2 t (cos $)9 (cos \[/)2
62 - » 2 + c"^^

(«*-

- J*) (a2 -
1

-«f)

(*9-

- a2) (ft4 -

-e«)

1

2 ' 2.2 „ 2 "I* -o „ 2 — "•

so that v*9 v^ are the two roots of the = n

(cos a?)2 (cos $)2 (cos \|/)2 _
a2 — u2 + 6* - u2 + c2 — d2" —

Cor. — Hence the = n to the wave surface may be obtained
by making

(cos 00) x + (cos <p) y -f ( cos 4/) s = v,

or if we please to apply Prop. (5), we may make

/(^-«ft(a«-V) A2 - Q (fl» - Q

V (^-/32)(a2-c2) ' + V (62 - a2) (62 - c2) *y

^x/E^s3EEM,M^v9

g/TresnePs Optical Theory of Crystals. 467

or, if we please,

/(q«q»-l)(q»^ fp^TlHP-*)

V (a2 - 62) (a2 - c2) ' T V (£2 - a2) (6* - c2) y

• V (c* - a2) (<* - 62)

and eliminating by differentiation (w) and (0) we obtain

a9 #9 ft2 v2 c2 #2

a2-^2-^2**2) + P-aP + tf + x* + c»~**+y*+»9 = V

Proposition 7.

To find when », = vw.

By Prop. 4,

*y fa9 - «2) _ y.to'-fr) = *, fa* - *3)
*«(V-«") *>,/-**) <W-*) ' "

Hence when & = vit we have, generally speaking,

(«•)

*« y» */, *

Now ^ *»J, + y, y„ •+ *, «j| = 0

... j. a _j_ yj. _j_ ^ -2 woul(] s- o, which is absurd.
The only case therefore when v, can = vn is when one of
those terms of = n (0) becomes — : thus suppose 0y= b, then

we have — I = ' = — , and we can no longer infer — ' = -^.

Let now (eo, <$i \(/,) (co„ <ptl ^n) be the two systems of values
which w, $, \|/ assume when v, = u/y = &, then applying the
= n of Prop. (5) we have

cos ., = y ^r^ cos «„ = ^ ^— ^

cos $, = 0 cos $„ = 0

. /&» -c2 J / 62 - c2

so that (6) must correspond to the mean axis.

Proposition 8.

i, %H being the < es made by the front with the optic planes

to find tt iu in terms of vt vlt.

302

468 Mr. Sylvester on the Optical Theory of Crystals.

By analytical geometry :

cos \t = cos CO . cos cot + cos $ . cos <p, + cos \J/ . cos \|/,

" V (a2 - F) (a2 - c») * V a9 - c2

/fa2~- c9) ( y - c2) /c2-&*

V (c2 - a2) (c2 - 62) ' V c* - a2

• (P<«- a2) (V - a*) + • (p» - c2) (V - c2),
(a2 - c2)
and similarly

cos iyi = cos co . cos cou + cos $ . cos fyj -f cos \J/ . cos tyu

_ j/(g - fl2) (g,,8 - «2) - V{vf - c%) (vn* - c2)
a2 - c*
Proposition 9.
To find vt vu in terms of ct cir
By the last proposition

cos , cos i - W-^)Kg-^)(^-^K9-c2)
cos i, . cos ttl _ ^ __ 2

_ («4-c4) -«2-c*. P/9+ *„'
(a3 - c2)2

_ (a* -f c») - tTTQ
(a2 - c2

.*. v? + 2^ = a9 -f c5 — (a* — c2) cos *y cos iir

Again,

(sin »,)2 . (sin *„)2 = 1 — cos i/— cos ij + (cos »y)9 (cos iyi)2

fa2 - a2) (V - a2) + fa2 - c*) (V - c2)
- L * ' ~~ (a2 - c2)*

, («2 4- c2)2 - 2 (ag + c2) W + V) + fo ,9 + V)2
+ (fl* _ t*f

(a* - c2)2
.\ t>,2 — v; * = (a* — c9) sin i, . sin iu
but a,9 -f vt ? = (a9 -f c2) — («9 — c9) cos h cos ia

9 a2 -f c2 a2 — c2 . , x
•'• *>/* = — „ 5 cos ('/ + •/,)

Zoological Society. 469

9 fl2 + C9 «2 — c9 , N

^ * = cos 0 — » )

" — 2 2

Thus for uniaxal crystals where it -f » = 80
t;* = a2

u,/2 = a2 . (cos /)2 + c2 (sin »)2.
[To be continued.]

LXV. Proceedings of Learned Societies.

ZOOLOGICAL SOCIETY.

Dec. 13, A Paper was read by William Ogilby, Esq., with a view
1836.* <£*- 0f pointing out the characters to which the most im-
portance should be attached in establishing generic distinctions among
the Ruminantia.

Mr. Ogilby commences by observing that " It has been justly re-
marked by Professor Pallas, that if the generic characters of the Ru-
minantia were to be founded upon the modifications of dentition, in
accordance with the rule so generally applicable to other groups of
Mammals, the greater part of the order would necessarily be comprised
in a single genus ; since the number, form, and arrangement of the
teeth being the same in all, except the Camels and Llamas, these
organs consequently afford no grounds of definite or general distinc-
tion. Hence it is that naturalists have been obliged to resort to other
principles to regulate the distribution of ruminating animals ; and the
form, curvature, and direction of the horns, selected for this purpose
at a period when the extremely limited knowledge of species permitted
the practical application of such arbitrary and artificial characters
without any very glaring violation of natural affinities, still continue
to be the only rule adopted by zoologists in this department of Mam-
malogy. The illustrious Illiger forms a solitary but honourable ex-
ception ; he first introduced the consideration of the muzzle and la-
chrymal sinus into the definitions of the genera Ant Hope, Copra, and
Bos ; but his labours were disregarded by subsequent writers, or his
principles applied only to the subdivision of the genus Antilope. It
is obvious, however, that as the knowledge of new forms and spe-
cies became more and more extensive, the prevailing gratuitous rule
above mentioned, founded as it is upon purely arbitrary characters
which have no necessary relation to the habits and oeconomy, or even
to the general external form, of the animals themselves, would even-
tually involve in confusion and inconsistency the different groups
which were founded upon its application ; and such has long been

* The preceding papers read at this meeting have been noticed in the
present volume, p. 196.

470 Zoological Society: Mr. Ogilby's

its acknowledged effect. The genus Antilope, in particular, has be-
come a kind of zoological refuge for the destitute, and forms an in-
congruous assemblage of all the hollow-horned Ruminants, without
distinction of form or character, which the mere shape of the horns
excluded from the genera Bos, Ovis, and Copra ; it has thus come to
contain nearly four times as many species as all the rest of the hollow-
horned Ruminants together ; so diversified are its forms, and so in-
congruous its materials, that it presents not a single character which
will either apply to all its species, or suffice to differentiate it from
conterminous genera.

'* To meet this obvious evil, MM. Lichtenstein, De Blainville, Des-
marest, and Hamilton Smith have applied Illiger's principles to sub-
divide the artificial genus Antilope into something more nearly ap-
proaching to natural groups ; the reform thus effected, however, was
but partial in its operation ; the root of the evil still remained un-
touched, for none of these eminent zoologists appears to have been
sufficiently aware of the extremely arbitrary and artificial character
of the principal group itself, which they contented themselves with
breaking up into subgenera, nor of the actual importance and exten-
sive application of the characters which they employed for that pur-
pose. By mixing up these characters, moreover, with others of a
secondary and less important nature, the benefit which might have
been expected from their labours has been, in a great measure, neu-
tralized ; and even the subdivisions which they have introduced into
the so-called genus Antilope, are less definite and comprehensive than
they might otherwise have been made.

" The truth is, however, that the presence or absence of horns in
one or both sexes ; the substance and nature of these organs, whether
solid or concave, permanent or deciduary ; the form of the upper lip,
whether thin and attenuated as in the goat, or terminating in a broad
heavy naked muzzle as in the Ox ; and the existence of lachrymal
sinuses and interdigital pores, are the characters which really influ-
ence the habits and ceconomy of ruminating animals, and upon
which, consequently, their generic distinctions mainly depend. These,
with the assistance, in a very few instances, of such accessory cha-
racters as the superorbital and maxillary glands, the number of teats,
and the existence of inguinal pores, are sufficient in all cases to de-
fine and characterize the genera with the strictest reference to logical
precision and zoological simplicity. It is not my intention to discuss
the value of these characters, or to state the reasons which induced
me to adopt them in preference to those more generally employed in
this department of Mammalogy ; these will form the subject of a
future communication, and I shall content myself for the present
with observing, that the presence or absence of horns in the females
regulates, in a great measure, the social intercourse of the sexes ;
that upon the form of the lips and muzzle, the only organs of touch
and prehension among the Ruminantia, depend the nature of the food
and habitat, making the animal a grazer or a browser, as the case may
be ; and that the existence or nonexistence of interdigital glands,
the use of which appears to be to lubricate the hoofs, has a very ex-
tensive influence upon the geographical distribution of the species ;

Arrangements of the Ruminantia. 471

confining them to the rich savannah and the moist forest, or enabling
them to roam over the arid mountain, the parched karroo, and the
burning desert.

" Having thus briefly explained the necessity of reforming the
characters of the different groups of the Order Ruminantia, as they
are at present constituted, and the nature and value of the principles
which I propose to employ for that purpose, I shall at once proceed
to their practical application, confidently anticipating that their
employment will remove the most serious objections which exist
against the present distribution of the order, and place our knowledge
of these interesting animals, in point of scientific accuracy, precision,
and affinity, on a par with the more generally cultivated departments
of zoology.

Fam. I. Camelid.e.

Pedes subbisulci, subtus callosi, digitis apice solo distinctis ; un-
gulae succenturiata? nulla? ; cornua nulla ; dentes primores supra
duo, infra sex.
2 Genera.

1. Camelus, cujus characteres sunt : Digiii conjuncti, immobiles.
Rostrum chilomate instructum, labro fisso. Sinus lachrymales nulli.
Fossa interdigitales nulla?. Folliculi inguinales nulli. Mamma qua-
tuor.

2. Auchenia : Digiti disjuncti, mobiles. Rostrum chilomate in-
structum, labro fisso. Sinus lachrymales nulli. Fossce interdigitales
nulla?. Folliculi inguinales nulli. Mamma duse.

" The Camelida form what Mr. MacLeay would call an aberrant
group ; they differ essentially from other Ruminants in the structure
both of the organs of locomotion and of mastication, and their ge-
neric distinctions consequently depend upon characters which have
no application to the remaining groups of the order. On the other
hand, the principles of generic distribution which subsist among the
rest of the Ruminantia appear to furnish negative characters only
when applied to the Camelidce; but though necessarily expressed
negatively, the absence of lachrymal, inguinal, and interdigital sinuses
forms, in reality, positive and substantial characters, and as such, as
well as for the sake of uniformity, should be introduced into the de-
finition of these, as well as of other genera, in which they unavoid-
ably appear under a negative form.

Fam. II. Cervid^:.

Pedes bisulci ; cornua solida, plerumque decidua, in mare solo, aut
in utroque sexu ; dentes primores supra nulli, infra octo.
6 Genera.

1. Camelopardalis. Cornua in utroque sexu, perennia, simpli-
cia, cute obducta. Rhinaria nulla. Sinus lachrymales nulli. Fossce
interdigitales parvse. Folliculi inguinales nulli. Mamma quatuor.
Duo species sunt C. JEthiopicus et C. Capensis.

2. Tarandus. Cornua in utroque sexu, subpalmata, decidua.
Rhinaria nulla. Sinus lachrymales exigui. Fossa interdigitales parvae.
Folliculi inguinales nulli. Mamma quatuor. Typus est Tarandus Ran-
gifer (Cervus Tarandus).

4; 7 2 Zoological Society : Mr. Ogilby's

3. Alcks. Cornua in mare solo, palmata, decidua. Rhinaria
nulla. Sinus lachrymales exigui. Fossa interdigitales magnae. Fol-
liculi inguinales nulli. Mamma quatuor. Typus est Alces Machlis
(Cervus Alces).

4. Cervus. Cornua in mare solo, ramosa, decidua. Rhinaria
magna. Sinus lachrymales distincti, mobiles. Fossa interdigitales
magnae. Folliculi inguinales nulli. Mamma quatuor. Typi sunt
C. Elaphus et C. Saumer aut Hippelaphus, Cuv.

5. Caprea. Cornua in mare solo, subramosa, decidua. Rhinaria
distincta. Sinus lachrymales nulli. Fossa interdigitales magna1,. Fol-
liculi inguinales nulli. Mamma quatuor. Typus est C. Capreolus.

6. Prox. Cornua in mare solo, subramosa, decidua. Rhinaria
magna. Sinus lachrymales maximi, mobiles. Sinus duo supraorbi-
tals ad basin cornuum, magni, mobiles. Fossa interdigitales magnae.
Folliculi inguinales nulli. Mamma quatuor. Typus est Prox Mos-
chatus (Cervus Muntjac).

Fam. III. MoschidjE.

Pedes bisulci ; cornua nulla ; denies primores supra nulli, infra octo.
2 Genera.

1. Moschus. Rhinaria magna. Sinus lachrymales nulli. Fossa
interdigitales nullae. Folliculi inguinales nulli. Mamma quatuor.
Typus est Moschus Moschiferus.

2. Ixalus ? Rhinaria nulla. Sinus lachrymales exigui, distincti.
Fossa interdigitales nulla?. Folliculi inguinales exigui. Mamma dua?.
Typus est Ixalus Probaton, present vol. p. 124, or Proc. Zool. Soc,
Part IV. page 119.

"The genus Ixalus, founded upon the observation of a single spe-
cimen, may eventually prove to belong to a different family ; it differs
little, indeed, from the true Antelopes : but even supposing it to
be correctly placed among the Moschida, other forms are still want-
ing to fill up the chasms which evidently exist among the characters
of that group. Two are more especially indicated, and our know-
ledge of the laws of organic combination and of the constituent parts
of other groups, gives us every reason to believe in their actual
existence, and to anticipate their discovery. They will be character-
ized nearly as follows, and will probably be found, one in the tropical
forests of the Indian Archipelago, and the other on the elevated table
lands of Mexico or South America.

Hinnulus. Rhinaria magna. Sinus lachrymales distincti. Fossa
interdigitales nulla?. Folliculi inguinales nulli. Mamma quatuor.

Capreolus. Rhinaria nulla. Sinus lachrymales nulli. Fossa in-
terdigitales parvas ? Folliculi inguinales? Mamma duae.

" It may appear a bold, perhaps a presumptuous undertaking, thus
to predict the discovery of species, and define the characters of
genera, of whose actual existence we have no positive knowledge ;
but, as already remarked, all the analogies of nature, whether derived
from organic combination or from the constituent members of similar
groups, are in favour of the supposition ; and I may observe further,
that the recent discovery of the genus Ixalus, if indeed it eventually
prove to be a genus, of which I had long previously defined the

Arrangements of the Ruminantia. 473

characters, as I have here done for the presumed genera Hinnulus
and Capreolus, strengthens my belief in the actual existence of these
forms, and increases the probability of their future discovery.

Fam. IV. Capridje.
Pedes bisulci; cornua cava, persistentia ; rhinaria nulla; dentes
primores supra nulli, infra octo.
7 Genera.

1. Mazama. Cornua in mare solo. Sinus lachrymales nulli. Fossa
interdigitales distinct*. Folliculi inguinales nulli. Mamma quatuor.
Typus est M. Furcifer (Antilope Furcifer).

2. Madoqua. Cornua in mare solo. Sinus lachrymales distincti.
Fossa interdigitales distinct*. Folliculi inguinales nulli. Mamma
quatuor. Typus est M. Saltiana (Ant. Saltiana et Hemprichii).

3. Antilope. Cornua in mare solo. Sinus lachrymales distincti,
mobiles. Fossa interdigitales maxim*. Folliculi inguinales maximi.
Mamma du*. Typus est A. Cervicapra.

4. Gazella. Cornua in utroque sexu. Sinus lachrymales distincti,
mobiles. Fossa interdigitales maxim*. Folliculi inguinales maximi.
Mamma du*. Typus est Gazella Dorcas (Ant. Dorcas).

5. Ovis. Cornua in utroque sexu. Sinus lachrymales exigui, im-
mobiles. Fossa interdigitales parv*. Folliculi inguinales nulli. Mam*
ma du*. Typus est Ovis Aries.

6. Capra. Cornua in utroque sexu. Sinus lachrymales nulli.
Fossa interdigitales parv*. Folliculi inguinales nulli. Mamma du*.
Typus est Capra Hircus. Ad hoc genus pertinent Ovis Tragelaphus,
et Antilope Lanigera aut Americana, Auct.

7. Ovibos. Cornua in utroque sexu. Sinus lachrymales nulli.
Fossa interdigitales ? Folliculi inguinales nulli. Mamma quatuor.
Typus Ovibos Moschatus.

Fam. V. BovidjE.

Pedes bisulci ; cornua cava, persistentia ; rhinaria distincta, nuda ;
dentes primores supra nulli, infra octo.
9 Genera.

1. Tragulus. Cornua in utroque sexu. Glandula maxillares ob-
long*. Fossa interdigitales null*. Folliculi inguinales nulli. Mam-
ma quatuor. Typus est T. Pygmaus (Ant. Pygmaa).

2. Sylvicapra. Cornua in mare solo. Glandula maxillares ob-
long*. Fossa interdigitales parv*. Folliculi inguinales distincti.
Mamma quatuor. Typus est S. Mergens (Ant. Mergens).

3. Tragelaphus. Cornua in mare solo. Sinus lachrymales magni.
Fossa interdigitales distinct*. Folliculi inguinales nulli. Mamma
quatuor. Typus est T. Hippelaphus (Ant. Picta) ; the Neel-ghae, and
not the Saumer Deer of India, as I shall show elsewhere, is the ani-
mal described by Aristotle under the name of Hippelaphus.

4. Calliope. Cornua in mare solo. Sinus lachrymales nulli.
Fossa interdigitales null*. Folliculi inguinales distincti. Mamma
quatuor. Typus est Calliope Strepsiceros (Ant. Strepsiceros) . ,-

5. Kemas. Cornua in utroque sexu. Sinus lachrymales nulli.
Third Series. Vol. 11. No. 69. Nov. 1837. 3 P

474? British Association for the Advancement of Science,

Fossce interdigitales magnse. Folliculi inguinales nulli. Mammce qua-
tuor. Typus est Kemas Ghoral {Ant. Goral).

6. Capricornis. Cornua in utroque sexu. Sinus lachrymales
magni. Fossce interdigitales distinctse. Folliculi inguinales nulli.
Mammce quatuor. Typus est C. Thar {Ant. Thar, Hodg.).

7. Bubalus. Cornua in utroque sexu. Sinus lachrymales exigui,
distincti. Fossce interdigitales magnse. Folliculi inguinales nulli.
Mamma duse. Typus est Bubalus Mauritanicus {Ant. Bubalus).

8. Oryx. Cornua in utroque sexu. Sinus lachrymales nulli. Fossce
interdigitales magnse. Folliculi inguinales nulli. Mammce quatuor.
Species sunt 0. Capensis {Ant. Oryx), Leucoryx, Leucophcea, &c.

9. Bos. Cornua in utroque sexu. Sinus lachrymales nulli. Fossce
interdigitales nullse. Folliculi inguinales nulli. Mammce quatuor.
Typus est Bos Taurus.

" I have here confined myself strictly to generic characters ; the
synonyma and discrimination of species will form the subject of a
future monograph ; in the mean time, with the assistance of the Ar-
ticle Antelope in the Penny Cyclopaedia, or, with the proper cor-
rections of Col. Smith's Treatise on the Ruminants in the fourth
volume of Griffith's Translation of the ' Regne Animal,' the student
will have no difficulty in referring any particular species to its appro-
priate genus. He will thus be enabled to judge of the correctness or
incorrectness of the affinities here indicated, and consequently to form
a tolerable estimate of the value of the characters by which I propose
to distinguish the genera of ruminating animals ; and indeed it is
principally from the wish to excite the attention of zoologists to
more extensive observation than I myself possess, that I have been
induced to publish the present analysis of my own investigations in
this department of Mammalogy."

Mr. Gould exhibited numerous examples of the genus Strix (as
at present restricted), from numerous parts of the globe, including
three undescribed species from Australia, which he characterized as
follows, the characters being given in No. 48 of the Society's Pro-
ceedings.

Strix castanops. Long. tot. 18 unc; rostri, 2\; alee, 15; caudce,
7 ; tarsi, 3^. Hab. In Terra Van Diemen. This is the largest known
species of the restricted genus Strix, of which the common Barn Owl
is a typical example. Strix Cyclops. One of the most beautiful spe-
cies of the genus. Strix delicatulus. Long. tot. 14 unc; rostri, If;
alee, 11; caudce, 4; tarsi, *2\. Hab. In Nova Cambria Australi. This
species in some respects very closely resembles the common British
Owl, St.flammea ; but it has a longer bill, and is considerably smaller.

BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE!
MEETING AT LIVERPOOL.

Sept. 11. Mr. Whewell rapidly sketched the principle on which his
instrument registered the quantity of aerial current passing any place.
He had exhibited the instrument in an unfinished state at the Dublin
meeting, and in a more matured state of its existence at Bristol ; it

Anemometers of Messrs. Whewell and Osier. 475

had since received some valuable improvements, which were suggested
by the practical working of the machine. That he might not occupy
the time of the Section too long, it would suffice at present to say,
that in it a small set of wind-mill vanes, something like the ventilators
placed in our windows, were presented to the wind by a common
vane, let the direction of the wind blow how it might : the aerial
current as it passed set these vanes into rapid motion, and a train of
wheels and pinions reduced the motion, which was thence communi-
cated to a pencil traversing vertically, and pressing against an up-
right cylinder, which formed the support of the instrument, and that
10,000 revolutions of the fly only caused the pencil to descend the one
twentieth of an inch. The surface of the cylinder was japanned white,
and the pencil as the vane wavered kept tracing a thick irregular line,
like the shadings on the coast of a map : the middle of a line was
readily ascertained, and it gave the mean direction of the wind actually
exhibited before the eye by a diagram, while the length of the line
was proportional to the velocity of the wind, and the length of time
during which it blew in each direction j which therefore gave what
he called the integral effects of the wind, or the total amount of the
aerial current which had passed the place of observation in the di-
rection of each point of the compass during the interval which had
elapsed since the time of last recording the instrument. This, it was
well known, was a subject of much importance in meteorological
speculations, but has not been hitherto accomplished. It was in-
deed deemed of much consequence, to obtain even the mean direction
of the wind at a given place, and the celebrated Kamtz, in his Mete-
orologie, has made a collection of several results of this kind; but, in
the ordinary way of registering even the direction of the wind, which
is, by stating the length of time it blows from a certain point of the
compass, it is obvious that the velocity of the wind is altogether left
out of account, and therefore the high wind or storm of one day, is
placed on a par with the gentle breeze of the next, and therefore not
an attempt can be made to infer the total quantity, or what he had
ventured to term the integral effect of the wind. Mr. Whewell then
exhibited large diagrams, giving the results of the observations re-
corded at the Cambridge observatory, under the care of Professor
Challis, and at the house of the Cambridge Philosophical Society.
The similarity of the curves showed a general coincidence, but some
discrepancies were accounted for by the fact, that the dome of the
Equatorial instruments sheltered the anemometers placed at the ob-
servatory on the north side, while that placed upon the house of
the Philosophical Society was well situated for receiving the wind from
every quarter. Anemometers on this principle had been also erected
by Professor Forbes and Mr. Rankin, at Edinburgh, and by Mr.
Snow Harris and Mr. Southwood, at Plymouth ; but he was not at
present prepared to state the results of the observations made with
them, though he had little doubt they would be interesting and
useful.

The President of the Section supposed it would rather suit the
convenience of the Section to hear Mr. Osier give the description of

3 P 2

476 British Association for the Advancement of Science.

his anemometer and rain-gauge, before they proceeded to make obser-
vations on the communication of Mr. Whewell: accordingly,—

Mr. Osier, of Birmingham, read an account of a new Registering
Anemometer and Rain Gauge, now in use at the Philosophical Insti-
tution, at Birmingham, illustrated by diagrams, giving a condensed
view of the observations recorded during the first eight months of the
year 1837.

He observed that although the results obtained by this instrument
are essentially different from those produced by the anemometer ex-
hibited last year at Bristol, by Professor Whewell, he should have
hesitated to introduce the one now submitted to the Section, had he
not been kindly encouraged so to do by that gentleman himself. In
this instrument the direction of the wind is obtained by means of the
vane attached to the rod, or rather tube that carries it, and conse-
quently causes the latter to move with itself. At the lower extremity
of this tube is a small pinion working in a rack, which slides back-
wards and forwards as the wind moves the vane, and to this rack a
pencil is attached, which marks the direction of the wind on a paper
ruled with the cardinal points, and so adjusted as to progress at the
rate of one inch per hour by means of a clock. The force is at the
same time ascertained by a plate one foot square, placed at right
angles to the vane, supported by two light bars running on friction
rollers, and communicating with a spiral spring in such a way that
the plate cannot be affected by the wind's pressure, without constantly
acting on this spring, and communicating the quantum of its action
by a light wire, passing down the centre of the tube to another pencil
below which thus registers its degree of force. The rain is registered
at the same time by its weight acting on a balance, which moves in
proportion to the quantity falling, and has also a pencil attached to
it recording the result. The receiver is so arranged as to discharge
every quater of an inch that falls, when the pencil again stands at
zero.

Mr. Whewell spoke highly of the construction of this anemometer,
and he had no doubt but that a very slight modification of the mode
of registering its indications would cause it to answer every purpose
which he had lately described as desirable. In its present form,
however, it was the force of the aerial current which it indicated, not
the integral effect. He also highly commended the rain-gauge, and
the method of showing to the eye in one diagram so many important
^meteorological phaenomena. — Professor Lloyd stated, that there was
a very simple method of causing the anemometer of Mr. Osier to
give the integral effect of the wind, and that was to cut out the paper
covered by the tracings of the pencil indicating the force of the wind,
and to weigh it ; for it was easy to perceive, that since the ordinates
of the curved spaces covered by those tracings were proportional to
the force, and, therefore, the velocity of the wind, and the abscissae
to the time, the areas represented the integrals, or the total amount
of the aerial current.. — Mr. Ettrick asked, whether some other method
of supporting the cylinder which moved back and forward as the
force of the wind varied, rather than friction rollers, would not be

Prof. Powell on the Dispersion of Light. 477

desirable—such, for instance, as bridle rods, or other means known
to practical mechanics, and, he was sure, well known to Mr. Osier.
Mr. Osier replied, that many methods of supporting this part of the
apparatus had been tried and laid aside, as not answering ; among
the rest, bridle rods.

Professor Powell then made a communication ■ On the Dispersion
of Light.' The object of this communication is to state the progress
of the inquiry into the subject of dispersion since the last meeting of
the Association. On that occasion, the author laid before the Phy-
sical Section the results of his observations for determining the re-
fractive indices of the standard rays for 28 media. These have been
since published, with some preliminary remarks, as one of the series
of memoirs of the Oxford Ashmolean Society. They are to be con-
sidered only as first approximations, and it would be very desirable
to have many of them carefully repeated, as well as to extend the
inquiry to other bodies. The author regrets that he has been unable,
from particular circumstances, to carry on these researches during the
past summer, but intends to take the first opportunity ot resuming
them. In particular, he was kindly favoured by Mr. Brooke with a
specimen of some crystals of chromate of lead for examination, and
accordingly put them into the hands of Mr. Dollond, who warmly
entered into his views, and has used every endeavour to give them a
prismatic form, but, unfortunately hitherto without success. It is
only by such co-operation of those engaged in different departments
of science that inquiries like the present can be successfully carried
on, and the author is anxious to obtain specimens of any transparent
media, which are capable of prismatic examination, and especially
such as are of high dispersive power.

Meanwhile, he has been engaged in the comparison of observation
and theory, especially among the more highly-dispersive bodies which
he has examined. He has performed the calculations by the method
of Sir W. R. Hamilton, and has found that for those media whose
dispersion is not very great, the coincidences are sufficiently close j
but, on proceeding to the more highly-dispersive bodies, especially
oil of cassia, the discrepancies increase, and moreover preserve a
certain regularity of character, which shows that they are not mere
errors of observation : this would seem to warrant the expectation,
that a further development of the formula might still give success-
ful results. These investigations have been communicated to the
Royal Society, and will appear in the next volume of its Trans-
actions.

Since the period of this communication, however, the able and
profound memoir of Mr. Kelland has appeared in the Cambridge
Transactions*. This gentleman's theory is, in some measure a
simplification of Cauchy's; the resulting formula, for the dispersion,
though substantially the same, as developed in a different form, and
readily capable of being applied to numerical computation. In some
correspondence with Mr. Kelland, that gentleman favoured the au-

* See Lond. and Edinb. Phil. Mag., vol. x., p. 336.

478 Royal Geological Society of Cornwall.

thor with a computation for the case of oil of cassia, in which the
greatest discrepancies existed. By this method, those discrepancies
have been made entirely to disappear ; and thus the most extreme case
at present known is brought under the dominion of the formula of
dispersion. It is also to be observed, that Mr. Kelland's series is
not rapidly converging j the neglected terms, therefore, may, if taken
into account, give a still more accurate result. It will, therefore,
now become of yet more extreme interest, to find some means of ob-
taining data for the more highly dispersive substances, such as chro-
mate of lead, realgar, sulphur, &c. With regard to the theory, there
may be much still wanting to render it entirely satisfactory.
Its first principles have been discussed by several mathematicians,
but especially in some papers read by Professor Lloyd to the Royal
Irish Academy, embracing, in fact, the whole subject of the propa-
gation of light in uncrystallized media.

Sir D. Brewster observed, that some other method than that of
observing the fixed lines of Fraunhofer, must be resorted to, for sub-
stances of such imperfect crystalline forms as those examined in this
communication, — as, for instance, the chromate of lead. The method
he would recommend, would be, either to interpose nitrous gas or
plates of mica, so as to form a net-work j a given number of the
colours of the resulting rings being then counted, and attended to
in the various observations, would be much better than Fraunhofer's
lines, which, indeed, in this case, he contended, would be altogether
incapable of being accurately observed. — Athenaum, Sept. 16.

ROYAL GEOLOGICAL SOCIETY OF CORNWALL.

The anniversary meeting of this Society was held at Penzance on
Monday, Oct. 16th, and it was never more fully attended.

The President, Gilbert Davies, Esq., opened the business of the
Meeting by a brief and eloquent address, and presented to the So-
ciety his editon of Hals and Tonkins' Parochial History of Cornwall,
from which he read many extracts relating to the rocks, minerals,
and other products of the county.

The Secretary then read the Report of the Council, which, after
noticing the demise of his late Majesty, the accession of the Queen,
and the continued royal patronage and support of the Society, and
proposing an Address to Her Majesty, proceeds as follows: —

" The labours of the Society during the past year have princi-
pally had reference to the organic remains which have been found
in different parts of this county : for although their existence in one
or two insulated spots was well known, no suspicion was entertained
of their occurrence in so many localities, and in such abundance.

" This year has also witnessed the completion of an object which
was one of the chief desiderata at the institution of this Society.
The valuable researches of many of its members, and of Dr. Boase
in particular, had given us a good general outline of the Geology of
Cornwall, and accurate details of many parts of it; but the labours
of Mr. De la Beche, under the direction of the Board of Ordnance,
have at length brought to perfection a Geological Map of the County,

Royal Geological Society of Cornwall. 479

executed with the accuracy for which that eminent geologist is so
distinguished. This and a book of reference are now in a forward
state, and they are to appear early in the ensuing spring.

"Although the Society cannot claim this useful and important
work as its own labour, it does not the less heartily greet its ap-
pearance, and rejoice in its accomplishment.

" Mr. Henwood's Survey of the Mines is also completed, and the
various particulars of it which have been from time to time brought
before the Society, with Dr. Boase's Memoir on the Diluvium of
Cornwall, and other communications, will appear in a fifth volume
of Transactions, now about to be put to press, and which will be
published in the course of the next year.

"The Donations to the Museum have been of great value and
importance, particularly an extensive suite of the Silurian rocks of
Murchison, by Mrs. Stackhouse, Acton ; of organic remains of the
elephant, rhinoceros, and other mammalia from the Sub- Himalayan
mountains, by Lieut. Tremenheere, of the Bengal Engineers; and of
the organic remains from the slates of our own county, by Mr.
M'Lauchlan, of the Ordnance Survey ; by Mr. Peach, officer in the
Preventive Service, at Gorran; and by the Curator. For the recep-
tion of these and other donations, more accommodation is required,
aud the Council propose to obtain it by the enlargement of the pre-
sent cases, and the addition of a new one.

"It being thought that the annual publication of papers read, or
abstracts of them, would induce more extensive communications to
the Society, the Council have desired the secretary to take the re-
quisite steps ; and this will be done for all such as may be presented
in the ensuing year.

" They cannot close their Report without alluding to the loss
which the Society has sustained by the removal of Dr. Boase, who
for so many years discharged the duties of Secretary with so much
honour to himself and advantage to the Society."

The Treasurer then read his report, which snowed the finances of
the Society to be flourishing; 173/. remaining in hand, after defray-
ing all expences, exclusive of the present year's subscriptions.

Thefollovoing Papers have been read since the last Report : — On the
Utility of a School of Mines in Cornwall : — on the probable sources
of its revenue: — and on the plan of management and of instruction
in such an Establishment ; by Henry S. Boase, M.D., F.R.S.,
F.G.S., &c, Hon. Mem. of the Society. On the Change of Level of
the Land and of Sea, in Cornwall; by Joseph Came, Esq., F.R.S.,
F.G.S., M.R.I.A., Treasurer of the Society. Note on the Seivaliks
or N. W. Sub-Himalayan belt of Hills; by Capt. P. T. Cautley,
Bengal Artillery,F.G.S., &c, Corresponding Member of the Society.
On the Fossils which occur in some of the Slates near Gorran, and
Fowey; by C. W. Peach, Esq., Associate of the Society. On the
relations which exist between Elvan Courses and the central Gra-
nite; by Joseph Carne, Esq., F.R.S., &c, Treasurer. On the ef-
fects of a trap-dyke on the contiguous strata in a Colliery in Durham ;

480 Royal Geological Society of Cornwall.

and on the Temperature of the Cornish Mines ; * by Robert Were
Fox., Esq., Vice- President of the Society. An account of the Quan-
tity of Tin produced in Cornwall and Devon, in the year ending with
the Midsummer Quarter, 1837 ; by Joseph Came, Esq.,F.R.S., &c,
Treasurer. An account of the quantity of Copper produced in Great
Britain and Ireland, in the year ending the 30th June, 1837 ; by
Alfred Jenkin, Esq.

The following gentlemen have been elected in the present year: —

Ordinary Members. — Captain Rowland, Penzance; Capt. Davies,
Penzance; R. E. A. Townsend, Esq., of London; Major Robyns;
Richard Thomas, Esq., of Penzance; Dr. Willin, of Penzance; Lewis
Stephens, Esq., of Tregenua Castle ; and Nicholas Phillips, Esq., of
Penzance.

Honorary Members. — Henry S. Boase, M.D., F.R.S., F.G.S., &c;
L. Cordier, of Paris, member of the Academy of Sciences ; W. H.
Fitton, M.D., F.R.S., F.G.S.; and R. J. Griffith, Esq., F.G.S., Pres.
Geo. Soc. of Dublin.

Corresponding Members. — Capt. Proby T. Cautley, F.G.S., of the
Bengal Artillery ; E. W. Brayley, Jun., Esq., F.L.S., F.G.S., Libra-
rian to the London Institution ; Edward Moore, M.D., F.L.S., Se-
cretary of the Plymouth Institution; Henry M'Lauchlan, Esq.,
F.G.S. ; and Lieut. G. B. Tremenheere, Bengal Engineers.

Associates. — C. W. Peach, Esq., of Gorran; Samuel Martyn, Esq.,
of Lower St. Columb; Captains Absalom Francis, of Halkin, Flint;
Thomas Richards, of Huel Vor; and Thomas Treweeke, of Halse-
town.

Officers of Council for the ensuing year.

President.— Davies Gilbert, Esq., D.C.L., F.R.S., F.G.S. Vice-
Presidents. — Wm. Bolliho, Esq.; Mich. Williams, Esq.; Right Hon.
Sir R. Hussey Vivian, Bart., G.C.B., M.P., &c; and W.Tyringham
Praed, Esq. Secretary. — (pro tempore) and Curator. — W. J. Hen-
wood, F.G.S. Treasurer.— Joseph Came, Esq., F.R.S., F.G.S. &c.
Librarian. — Richard Hocking, Esq. Council. — B. P. Baker, Esq.;

D. B. Bedford, Esq.; Richard Davey, Esq., F.G.S. ; J.S. Enys, Esq.;
R. Were Fox, Esq.; Day Perry le Grice, Esq.; Richard Harvey, Esq.;
John B. Pentreath, Esq. ; C. W. Popham, Esq.; Rev. John Punnett ;

E. Hearle Rodd, Esq.; and Rev. Canon Rogers.

* A brief but animated discussion between the author and Mr.Henwood
followed the reading of this paper: the former insisting that water was the
medium of transporting heat in the earth; the latter inquiring why, then,
the lower and less permeable rock (granite) was at the same depth colder
than slate, and why the water occurring in the slate, if coming from below,
was not seen in the granite through which it must inevitably pass in its way
upward ?

4-81
LXVI. Notices respecting New Books.

UNDER the following head, which will be continued and ex-
tended in future Numbers, it is designed to give the titles, and
sometimes short notices, of important foreign works, and of the
most interesting papers which appear in foreign Journals and Trans-
actions, especially those of Germany, Sweden, Holland, and Russia,
as being probably least accessible to the generality of readers.
Some of our respected correspondents have expressed a wish for
such information ; and the diffusion of it may further the objects
which the publication of the Scientific Memoirs is designed to
promote, and may, perhaps, assist in making the best selection of
papers for the future parts of that work, should the sale of the Volume
already published encourage the Editor to continue it. — R. T.

Bibliographical Bulletin.

Skandinaviens FisJcar. (The Fishes of Scandinavia), by B. Fr. Fries
and C.U. Ekstrom. Part 1. 4-to. Stockholm, 1836.
It is a great pity that the authors, well known to zoologists, have not
employed a more general language, Latin or French, instead of the Swedish
with which the greater number of naturalists are unacquainted. The
drawings are well executed and coloured with the greatest care from living
specimens so that few can be found to equal them.

Neues System der Pflanzen-Physiologie. (A new System of Vegetable
Physiology), by F. J. F. Meyen. Berlin, 1837. 8vo.
The first volume treats in the first book on the organs of assimilation
and formation ; in the second, on the organs of respiration and secretion ;
and concludes with a comparison of the types according to which the ele-
mentary organs in the stems of Monocotyledons, Dicotyledons and Acoty-
ledons are arranged. The author not only gives the results of his own
labours but carefully relates those of other botanists. The second volume
is to appear next year.

Lehre von der Cohesion (Doctrine of Cohesion), by Prof. M. L.
Frankenheim. Breslau, 8vo.

This work is divided into several parts, containing " Elasticity of Gases,
Elasticity and Coherence of fluid and solid Bodies, and Crystallography," &c.

Poggendorff"s Annalen, 1837. No. 5.

Contents.— On the Nature and formation of Coral islands and of the
Coral banks in the Red Sea; by C. G. Ehrenberg. (This paper is highly
interesting.) — On the changes of specific gravity which Sea-water under-
goes from heat, by A. Erman. — Harris's Electrical experiments in rarefied
air, by Dr. Riess, (This is a repetition and full confirmation of Mr. Harris's
experiments, which are recorded in Phil. Transact, for 1 834). — On the places
of the Maxima and Minima of the wave-surface, according to the ob-
servations of Fresnel; by K. W. Knockenhauer. — Artificial formation of
twin crystals which exhibit without any previous polarization epopoptical
figures similar to those observed in Arragonite ; by J. Miiller. — Additional
notice respecting experiments on vinous fermentation and putrefaction;
by Th. Schwann. — Description of two new Lamps (for organic analysis and
glass-blowing); by H. Hess. — On the Fusibility of Iridium; by Bunsen. —

Third Series. Vol. 1 1. No. 69. Nov. 1837. 3 Q

482 Intelligence and Miscellaneous Articles.

■s

A new method of dissolving Iridium ; by L. R. Fellenberg. — On the deter-
mination of the expansion of crystallized bodies by Heat ; by E. Mitscherlich.
— Analysis of an antimony ore from Nasafjeld in Lapland ; by M. C. J.
Thaulow. (A notice of this will appear in the next Number of Phil. Mag.)

Wiegmann's Archiv, Part 3. Berlin. 1837.

Contents. — Description of two monstrous Echini, together with some
general remarks on Echinidce ; by Dr. Philippi. — On Gorgonia paradoxa ; by
the same. — Contributions to the history of the genera Campanularia and
Syncoryne\ by Lowen. — Ichthyological Appendices to the Fauna of Green-
land ; by Prof. Reinhard. — On the genera of Fossil Infusoria Xantkidium
and Peridinium; by C. G. Ehrenberg. — On Fossil Infusoria; by the same. —
Notice on the action of free Carbonic Acid on the nutriment of Vegetables;
by Dr. M. J. Schleiden. — Diagnoses of some new species of Shells; by
Anton.— Report on the Progress of Vegetable Physiology during the year
1836 ; by J. Meyen. (Translation now appearing in Phil. Mag.)

Neue Notizen von Froriep, vol. ii. contains ;

No. 9. Effects of Galvanism on animal ceconomy. — Climate of Scandi-
navia; by Forsell.— On the place which Dinotherium must occupy in the
natural classification of Mammalia.— No. 10. Appendices to the natural his-
tory of Man; by Prof. J. van der Hoeven. — No. 14. New experiments on
the action of the Torpedo ; by Santi Linari. — Experiments on the Voice;
by Bishop (from Phil. Mag.).— On Spermatozoa. — On the influence of
aqueous vapour on all periods of Vegetation.

Journal fur praktische Chemie, by O.L. Erdmann. Part 6. contains:
On the Silvering of Brass; by Dernen.— Sulphate of Zinc with 3| M. G.
of Water; by Anthon.— On the application of Metallic Sulphurets pre-
pared in the moist way to chemical analysis; by the same.— Simple me-
thods of determining Ammonia, both quantitative and qualitative, in chemi-
cal analysis ; by the same. — Analysis of a Mineral water which had sud-
denly changed; by E. von Bibra. — On the Reduction of the Sulphuret of
Arsenic. — Hints for the Improvement of the Quick Manufacture of Vinegar ;
by E. F. Anthon. — A new Method of preparing Iodic Acid; by Louis Thomp-
son (from Phil. Mag.). On the Purple-red Colour produced by chloride
of gold on animal fibre. On the aethereal Oil of Wine.— Enigmatical
Phenomenon of a Mutation of Colours ; by H. Ch. Creuzburg.

Comptes Rendus, No. 14. 1837. Oct. 2.

Contents. — On some fossil Teeth from Oran ; by Duvernoy. — On the
Geographical Distribution of Birds of Passage in South America; by
A. d'Orbigny. — RecentExperiments on the Torpedo; by Matteucci. — Sul-
phate of Nitrogen; by Soubeiran. — On the Erratic Blocks of the Jura; by
Agassiz. — Letter on the presence of Animalcules in various Secretions and
Excretions of diseased patients ; by Beauperthuy and Adet de Rouville.
(Worthy of notice.) No. 15. Oct. 9. — Note on the Development of the
Embryo in the cephalapodous Mollusca; by A. Duges.— Researches in
Animal Electricity; by Matteucci.— On some new Mammifera; byJourdan.

LXVII. Intelligence and Miscellaneous Articles.

SOLUBILITY OF ARSENIOUS ACID.

MR. Taylor, lecturer on chemistry at Guy's Hospital, has made
numerous experiments on this subject, to the detail of which,
as inserted in the following pages, he has prefaced the summary also
annexed of the results obtained by other chemists.

Mr. Taylor on the Solubility of Arsenious Acid. 483

" One thousand parts of temperate water dissolve, of their weight
of arsenious acid, according to —

Despretz, La Grange, Bucholz, Guibourt, Hahnemann,

STJ 2(7 3TI WU 30

Spielmann, Ure, Klaproth, Fischer.

" The results of some of these experimentalists were probably ob-
tained by boiling the water on arsenious acid, allowing the solution
to cool, and then estimating the quantity dissolved ; while those of
others were probably deduced from the actual digestion of the poison
in cold water. It is perhaps in this way that we may reconcile the
enormous difference between the statements of Despretz and Fischer j
the former making arsenic sixty times more soluble than the latter.

" One thousand parts of boiling water dissolve, of their weight of
arsenious acid, according to

Guibourt, Bucholz, Klaproth, Ure, La Grange, De la Metherie,

k TT tV • A iV fa

Vogel, Beaume, Navier, Nasse,

"sV "fa SO 200

* The differences in this table may perhaps be explained, by sup-
posing that a heat of 212° may have been applied for different periods
of time j as also that specimens of arsenious acid, probably varying
considerably in their degree of purity, may have been employed.

" It was the discovery of these very different results, respecting the
solubility of arsenic, by men of well-known authority as chemists, that
first induced me to endeavour to ascertain which statement was borne
out by experiment.

" In relation to specific gravity, I found that of a mass of arsenious
acid which had been kept four years, and was perfectly opaque — pre-
senting, when fractured, a slightly crystalline structure — to be 3*529.
Having procured a recently-prepared specimen, perfectly transparent,
but of a slightly-yellowish tinge, I tried its specific gravity, and found
it to be 3798.

" Arsenious acid, it may be remarked, is soluble in water, oils, and
alcohol. Water is its most common solvent : and it is, therefore, of
its solubility in this menstruum that I shall first proceed to speak.
The water employed in the experiments mentioned below, was the
common water of the Hospital, which is the Thames water, filtered.
It contains, comparatively, little foreign matter. A given measure of
this water weighed 7527 gr. ; while the same measure of recently-dis-
tilled water weighed 752 gr. Its specific gravity will therefore be
1 -00093. Distilled water was not employed in these experiments,
since I had a medico-legal object in view : in no case of criminal
poisoning is it likely that distilled water will be used by the suicide or
murderer. In the course of many experiments, however, there did
not appear to me to be the least appreciable difference in the solvent
power of water over arsenious acid, whether distilled, or common river-
water filtered, was employed.

" Exp. 1 . Twenty grains of opaque arsenious acid, reduced to a fine
powder, were placed in a clean glass vessel, and eight fluid ounces of

3 Q2

484? Intelligence and Miscellaneous Articles.

boiling water were poured on. A portion of the powder collected into
small lumps, which floated, and, even after violent agitation, adhered
to the sides of the vessel; while another portion sank to the bottom.
The vessel remained covered seventy-two hours • the contents being
frequently agitated, to ensure perfect contact and admixture. The
water was then carefully filtered, and the filter dried. The residuary
undissolved powder weighed 10*46 gr. Therefore,

20-1046=0-54 gr. dissolved by f Sviij. or (500x8) 4000gr. water;
and 4000-^954=419 } as also 9 54-j-4=2-385 gr.
Hence,

1000 parts water at 212°, dissolved 2-385 pts. or ^fr.

" Exp. 2. A similar experiment was performed; and the residuary
powder obtained on the filter weighed 9*27 gr. Therefore,

20— 9 27=10-73, dissolved by fg viij. or (500x8) 4000 gr. water;
and 4000—10-73=372; as also, 1 0-73-f- 4=2-6825 gr.
Hence,

1000 parts water at 212° dissolved 2-6825 gr. or -^.

" Twenty-five grains of each of these solutions, filtered, were now
evaporated to dryness, at a low temperature ; and '06 gr. were ob-
tained as the mean weight of the residue of several successive evapo-
rations of Exp. 1 . ; and '07 as the mean for Exp. 2. ; results which
come as near to the proportions above ascertained as could be well
expected, considering that distilled water was not employed.

M The mean of the Exps. 1 and 2 will be the following : 1000 gr.
of boiling water, allowed to cool, and remain 72 hours (with frequent
agitation), on 20 gr. arsenious acid, will dissolve 2*53 gr., or about
-r^-s- of their weight.

" Exp. 3. Two ounces of water were kept gently boiling for an
hour, the waste by evaporation being made up ; and while boiling,
finely powdered arsenious acid, in small quantities at a time, was gra-
dually added, from a previously weighed quantity. No further por-
tion was added until that which had been previously added was dis-
solved. The result was, that,

1000 gr. of water (fgij.) dissolved .... 315 gr. or ?V-
This solution was placed aside for 72 hours ; and at the end of that
time it was found to have deposited in brown octohedral crystals, 14*5
gr. ; and 31*5— 14*5=17 gr. Hence,

1000 grains water (f gij.) held dissolved, on perfect cooling, 17 grains, or^V
Twenty-five grains of the cold solution were slowly evaporated to dry-
ness ; and the mean of several evaporations gave *4 1 gr. as a residue,
which is a little below the proportion as above ascertained.

" Exp. 4. Two ounces of water were kept violently boiling for an
hour, the waste by evaporation being made up ; and arsenious acid
was gradually added from a weighed quantity, as before. It was then
found that

1000 gr. of water had dissolved . . . 463 or ,4.
From this solution there were deposited in crystals, after 72 hours,
21*6 gr. and 46*3—2 1-6=247 gr.

1 000 gr. water, held dissolved, on perfect cooling, 24-7 gr. or TV-

Mr. Taylor on the Solubility of Arse?iious Acid. 485

Twenty-five grains of the cold solution, evaporated, left *55 gr., rather
less than the proportion deduced from the weight of the undissolved
residue.

" Exp. 5. In this experiment four ounces of water were kept vio-
lently boiling for half an hour ; arsenious acid being added, as before,
from a weighed quantity. 89 gr. were dissolved. Hence,

1 000 gr. water dissolved (89-*- 2) . . . 44 5 gr. or about £?.
The mean of Exps. 3, 4, and 5, will be the following :

1000 gr. of boiling water dissolve .... 40*76 gr. or -yV*
The rapidity of boiling will make a considerable difference in the quan-
tity dissolved, as will be seen on comparing Exps. 3 and 4. Indeed,
water which boils violently will dissolve as much arsenic in half an
hour as water kept gently boiling will dissolve in an hour. All other
circumstances being equal, the length of time during which the boiling
continues will assuredly make a difference in the quantity of the poison
taken up.

" Exp. 6. Arsenious acid, in fine powder, was boiled for several
hours to saturation, in two separate quantities of water. These solu-
tions were, after filtration, kept apart j and allowed to stand for six
months in well-stoppered bottles. A very abundant crop of oetohe-
dral crystals, lining the whole interior of the bottle, was deposited in
each case. After this lapse of time, twenty-five grains of the filtered
solution (A) were evaporated to dryness $ and the solid residue weighed
*7 grain. Hence,

1000 gr. of the solution contained 40 x *7=28" gr. or &..
Twenty-five grains of (B) left, as a solid residue, *6 gr. Hence,

1000 gr. held dissolved 40 X *6=24 gr. or nearly ^.
The mean of these two experiments will be as follows :

1000 gr. of a saturated solution, after six months' standing, held
dissolved 26 gr. or -j-g.

" In closing these remarks on the solubility of arsenic in boiling
water, I shall subjoin the results of some experiments on the recently-
prepared, or transparent, arsenious acid : and I am the more desirous
of doing this, since the statements of Guibourt, relative to the trans-
parent being less soluble than the opaque variety, are not supported
by them. In a medico-legal point of view, the question of a differ-
ence of solubility in these varieties of arsenious acid is not, perhaps,
of much importance ; since the pure transparent arsenic is with dif-
ficulty obtainable, and is rarely sold by druggists.

'* Exp. 7. A perfectly transparent and recently-prepared mass of
arsenious acid was finely pulverized j and a weighed quantity of the
powder was gradually added to two fluid ounces of water, kept violently
boiling for an hour, the waste by evaporation being made up. Forty-
six grains were dissolved.

1000 gr. water dissolved .... 46 gr. or nearly -5V.

From this solution there were deposited in crystals, after 48 hours,
27-3 gr. and 46—27*3= 187.
1000 gr. water held dissolved, on perfect cooling .... 18*7 gr. or ^v.
" Exp. 8. In this experiment four ounces of water were kept boil-

486 Intelligence and Miscellaneous Articles.

ing for an hour, and pulverized transparent arsenic was gradually
added. There were dissolved 95*1 gr. Hence,

1000 gr. water dissolved (95- 1-*- 2) .... 47*55, or t^.
From this solution there were deposited, in crystals, after 48 hours,
68*3 gr. Hence, 95-1 -68-3=26 8—2= 134 gr.
1000 grains of water, held dissolved, on perfect cooling, 13*4 grains, or^.
The results of these experiments show, that there is certainly not al-
ways the difference in the degree of solubility of these two varieties of
arsenic, which M. Guibourt suspected ; and which, upon his author-
ity, is to be found stated in many chemical and medico-legal works.
The quantity dissolved, of either variety, under similar circumstances,
according to these experiments, may be regarded, for all practical
purposes, as the same.

'* In cases of criminal poisoning, it occasionally happens that cold or
temperate water is used as the solvent for this poison, and a witness
is expected to state the degree of its solvent powers. The considera-
tion of this, led to the performance of the following additional expe-
riments.

" Exp. 9. Eight fluid ounces of temperate water were poured upon
twenty grains of the pulverized opaque arsenic, in a clean glass vessel.
The powder immediately collected in lumps, which partly floated and
partly remained at the bottom of the vessel. A slight film of powder
formed by repulsion on the surface of the water. The vessel was
covered over, and allowed to stand 72 hours, having been first well
agitated. The liquid was filtered, and the filter carefully dried. The
residual undissolved powder weighed 1 6 gr. And20— 16=4. Hence,
1000 gr. water (f^ij.), dissolved .... 1 gr. or -r^Vir*

Twenty-five grains of the filtered solution, evaporated, left '03 gr. •
which is nearly equal to the proportion above determined from the
undissolved residue.

" Exp. 10. Another experiment was performed, which only differed
from the preceding in the circumstance of the vessel having been fre-
quently agitated. The undissolved powder left on the filter, after dry-
ing, weighed 1 1*5 gr., and 20— 1 1*5 =8"5 gr. Hence,

1000 gr. water (f^ij.), dissolved .... 8'5-r4=2125 or «}*.

Twenty-five grains of the filtered solution were evaporated ; and left
not quite -06 gr., a proportion rather larger than that above deduced.

" It follows, from these experiments, that very nearly the same quan-
tity of arsenious acid is taken up by hot water allowed to cool, and
cold water poured on this substance in powder ; provided the vessel
containing the cold water be frequently agitated. They also show
the necessity for a continued application of heat, in order that the
poison should be dissolved in any considerable quantity. It is a cu-
rious, and hitherto an unexplained fact, that water should retain so
much more of this poison, as from ten to twenty times the quantity,
when perfectly cooled from a boiling saturated solution, than it will
take up at common temperatures without heat. It would seem to
indicate, that heat must excite some permanently powerful affinity

M. Lassaigne on Stearic JEther and Stearate of Methylene. 487

between the particles of arsenious acid and water, which did not pre-
viously exist."

Note. It remains to be explained why 1000 grains of a saturated
and cold solution, as in Experiment 6, contained 26 grains of arsenious
acid, whereas by Experiment 7, it appears that an equal quantity of
a solution also saturated and cold contained only 18*7 grains. — R.P.

STEARIC iETHER AND STEARATE OF METHYLENE.

M. Lassaigne obtained the above-named compounds by treating
stearic acid with a mixture of alcohol and sulphuric acid, or by a mix-
ture of the same acid with pyroxilic spirit.

Stearic aether has the following properties : it is solid, white, and
semi-transparent like wax ; it is lighter than water; its odour is not
very marked, but is slightly ethereal j it is tasteless, and does not act
upon litmus paper. The fusibility of this compound is so great that
it melts when pressed between moderately warm fingers, or when rubbed
in the palm of the hand j it is insoluble in water, but soluble in alco-
hol, and more so when hot than cold. When treated with a hot so-
lution of potash, it gradually decomposes, and there are reproduced
stearic acid, which remains combined with the potash, and alcohol,
which is disengaged with the vapour of water. It appears from ana-
lysis that this aether consists of

Stearic acid 87*9 1

.-Ether 1209

100-
or an atom of stearic acid combined with one of aether.

The stearate of methylene, prepared by heating stearic acid with a
mixture of sulphuric acid and pyroxilic spirit, is solid, and lighter than
water ; it is a confusedly crystalline mass, which is yellowish and se-
mi-transparent; its smell is very slight. It softens between the fingers,
and soon fuses ; its melting point is about 90° Fahr. It does not act
upon litmus, is insoluble in water, and decomposed by hot alkaline
solutions. This compound, with respect to the relation existing be-
tween its elements, seems to approach the oxalate of methylene and
analogous compounds. — Unstitut; Aout, 1837.

METEOROLOGICAL OBSERVATIONS FOR SEPTEMBER 1837.

Chiswick. — Sept. 1. Cloudy: thunder showers. 2. Cloudy and fine.

3. Showery. 4. Cloudy: clear and cold at night. 5. Hazy: cloudy

and fine. 6. Foggy : very fine. 7. Fine. 8. Rain : sultry. 9, 1 0. Cloudy.
11. Fine. 12 — 14. Cloudy and fine. 15. Clear. 16—18 Overcast.

19, 20. Very fine. 21, 22. Foggy : very fine. 23, 24. Dry and windy.
25, 26. Clear and fine. 27, 28. Cloudy and fine. 29, 30. Foggy :

very fine.

Boston. — Sept. 1. Fine. 2. Fine : rain p.m. 3. Cloudy : rain a.m.

and p.m. 4. Cloudy. 5, 6. Fine. 7. Cloudy. " 8. Fine.

9. Cloudy : heavy rain p.m. 10. Fine. 1 1. Fine : rain p.m. 12. Fine.
13. Cloudy: rain early a.m. 14. Cloudy: rain a.m. 15. Fine: ram

P.M. 16. Cloudy: rain p.m. 17. Cloudy. 18. Cloudy: rain

early a.m. : rain a.m. 19—21. Cloudy. 22—24. Fine. 25. Fine :

rain a.m. 26. Fine. 27 — 29. Cloudy. 30. Fine.

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T II K

LONDON and EDINBURGH

PHILOSOPHICAL MAGAZINE

AND

JOURNAL OF SCIENCE.

[THIRD SERIES.]

DECEMBER 1837.

LXVIII. On the Action of Chromic Acid upon Silver, and its
Combinations with the Oxide of that Metal, By R. Wa-
zington, Esq.*

"IIlTHEN liquid sulphuric acid is added to a solution of the
7 bichromate of potass and a plate of silver immersed,
or the mixed solutions poured into a silver capsule, an imme-
diate chemical action takes place, and the whole surface of
the metal becomes covered with a scarlet-coloured precipitate,
which in a very short time assumes a crystalline structure,
and is changed to a dark crimson ; this salt is the bichromate of
silver, as will be demonstrated by analysis in a subsequent part
of this paper. The precipitate should be removed at intervals
to facilitate the progress of the action, as it would otherwise
form a coating over the surface of the silver and prevent the
acid from acting with its full energy. During this operation
the colour of the supernatant liquid becomes much deeper,
until the orange red tint of the original solution has become of
a dark mahogany hue, and it then passes gradually into a deep
green. This solution yields by evaporation one or two s uts
that will be hereafter described, and a large quantity of very
fine octohedral crystals of the double sulphate of the prot-
oxide of chromium and potass, or chrome alum.

Now to account for these phenomena, it must be evident
both from the nature of the materials employed, and also of
the compounds arising from their action, that the silver must
become oxidized (this being necessary before any combination
can take place between it and the chromic acid) at the ex-

* Communicated by the Author.
Third Series. Vol. 11. No. 70. Dec. 1837. 3 R

490 Mr. Warington on the Action of Chromic Acid upon

pense of the chromic acid of the bichromate of potass, and
that the chromic acid must therefore be divided into two parts,
the first of which, yielding oxygen to the metallic silver, forms
the oxide of that metal, which is directly seized by the se-
cond, or undecomposed part of the chromic acid, giving rise
to the crimson crystalline salt or bichromate of silver; while
at the same time the deoxidized chromic acid or protoxide of
chromium of the first part, enters into combination with the
sulphuric acid and the potass of the bichromate of potass, to
form the chrome alum; the sulphuric acid taking no part in the
decomposition, but acting merely as a necessary agent to in-
duce the stronger affinities, and to unite with the protoxide of
chromium and the potass as soon as liberated from their re-
spective combinations.

For the perfect success of this experiment care should be
taken that the plate or capsule of silver employed is rendered
perfectly clean, and free from any coating of sulphuret or chlo-
ride of that metal. I have usually, after rubbing the surface
with a little fine emery powder, washed it with solution of
ammonia before bringing it into contact with the mixed solu-
tion, and have always found the action to commence imme-
diately. The proportions that appear to afford the most com-
plete results are one proportion of the bichromate of potass,
or about 150 grains, dissolved in water, and three or four pro-
portions of liquid sulphuric acid, or from 150 to 200 grains
by weight, equal to from 76 to 102 grains by measure.

The bichromate of silver crystallizes in rhomboidal plates,
having frequently two of the angles opposed to each other
truncated; it has an acid reaction, is slightly soluble in water,
yielding a rich amber yellow solution, which deposits very
dark brown crystals by spontaneous evaporation ; these how-
ever are crimson by transmitted light, and when rubbed down
in a mortar give a crimson powder.

The bichromate of silver is also formed whenever an acid
salt of silver is precipitated by the bichromate of potass, and
even at times by the neutral chromate, as is the case with the
sulphate of silver ; and although the fact of a crystalline pre-
cipitate of chromate of silver being sometimes obtained is
mentioned in many of the best works on chemistry, yet the
composition, or a difference in composition from the brown-
red precipitate of chromate of silver as it usually occurs, is
never hinted at. In making this statement, however, I should
except the Traite des Essais par la voic scche of M. Berthier,
and also a short notice by Mr. Teschemacher in the Phil. Mag.
and Annals, N.S. vol. i. p. 34-5.

20 grains of the bichromate of silver obtained by the pro-

Silver, and its Combinations with the Oxide of that Metal, 491

cess given in the former part of this paper and reduced to a
fine powder, were acted upon by very dilute hydrochloric
acid and boiled ; this threw down chloride of silver, which
when well aggregated by the boiling was thrown upon a
double filter and carefully washed, and gave, after being dried
and heated to incipient fusion, 13*1 grains, equivalent to 10*5
grains of the oxide of silver.

To the filtered solution a small quantity of alcohol was
added, and the whole boiled until a perfect deoxidation of the
chromic acid had taken place ; the alcohol was then evaporated
off, and the protoxide of chromium precipitated by a solution
of caustic ammonia added in slight excess; this after being
well washed, dried, and heated to full redness, weighed 7*2
grains, which are equivalent to 9*36 grains of chromic acid.
We have therefore the following proportions for the compo-
sition of this salt, corresponding as closely as we can expect
with the theoretical constitution of the bichromate of silver.
By Experiment. By Theory. Atoms. AtomicWeight.
Chromic acid 9*36 9*455 2 104

Oxide of silver 10-59 10*545 1 116

19*95 20-000 220.

When the above salt is boiled in distilled water a part of
it is dissolved, and separates in beautiful micaceous crystals
of a very rich crimson colour as the solution cools, while at
the same time another part of the salt is resolved into chromic
acid and a very dark green crystalline chromate of silver,
crimson however by transmitted light, and yielding by tri-
turation a powder similar in colour to the precipitated chro-
mate. This after being well washed and dried was submitted
to exactly the same method of analysis as the bichromate of
silver, (as were also the two salts next mentioned,) and gave
from 2-1 grains.

By Experiment. By Theory. Atoms. Atomic Weight.
Chromic acid -646 '65 1 52

Oxide of silver 1*440 1-45 1 116

2-086 2-10 16S

The precipitated chromate, obtained by adding a solution
of the yellow chromate of potass to one of the nitrate of sil-
ver, yielded exactly the same results.

The bichromate of silver is readily soluble in ammonia,
affording a clear pale yellow solution, which by exposure to
the atmosphere has a dark green pellicle or crust formed on its
surface, having a metallic lustre, and being of a rich claret
colour by transmitted light, giving however the same kind of

3 R2

492 Mr. Lubbock on the Variation of the

red-brown powder by trituration, and having exactly the com-
position of the two preceding salts. After this green crust
has been separated, crystals of chromate of silver and am-
monia of a pale yellow colour form (this salt has been carefully
examined by Professor Mitscherlich), and lastly bichromate
or chromate of ammonia separates.

Should it be wished to obtain the double chromate of silver
and ammonia, care should be taken to exclude the air, as
the ammonia rapidly passes off and destroys the object in
view. I have found that when placed in a partial vacuum
over quicklime, an atmosphere of ammonia is formed around
the solution, while at the same time the lime is gradually
absorbing the watery vapour.

In a future communication I hope to consider the action of
chromic acid upon some of the other metallic bodies, as well
as to recite an examination of a variety of double chromates
formed during that action.

LXIX. On the Variation of the Arbitrary Constants in
Mechanical Problems, By J. W. Lubbock, Esq., F.R.S*

HPHE general theory of the variation of the arbitrary con-
-*■ stants in mechanical problems, with reference to the dif-
ferential coefficients of the disturbing function considered as
a function of those coefficients, as hitherto exposed, appears
susceptible of several simplifications.

Suppose the differential equations of any dynamical pro-
blem to be

d*x dV dR _
dt2 dx dx

, dx

X ~ dt

dt' dy dy

* dt

d2z dV dR_
dt2 dz dz

, dz
' ~~dt9

and that a, b, c, &c. are constants which enter into the accu-

rate integrals of the equations

d2x dV d*y dV
dt2 + dx = ' dt* + dy~

0,

d2z dV
d¥ + ~dz~ ~ a

This general theory of the variation of the arbitrary con-
stants in mechanical problems may be said to consist in the
following theorems ;

* Communicated by the Author.

Arbitrary Constants in Mechanical Problems. 493

I. -t — dt = (b9 a) db + (c9 a) dc-\-(eta) de + &c.

II. r/«= \b,a]^ dt + \c,a}^dt+\_e,a]~^ dt + &c.

L J do L J dc L J ac

with similar equations for the constants b, c, e, &c. (b, a),
(c,a)9 (e, a), &c. \b, a\ [c, a], [e, a], &c. being the same as
in the notation of M. Poisson, Memoir es de V Institute 1816.

III. That the quantities (&, a), (c, a), (e, a), &c. and also the
quantities [6, a], \_c, a], [e, a], &c. are constant.

The well-known proof which M. Poisson has given of the
expressions which constitute the Unci theorem appears as
simple and direct as can be desired. See the TheorieAna-
lytique du Systeme du Monde, torn. L p. 222. I shall begin by
proving the 1st theorem.

Considering R as a function of or, y, z, #',?/, z',

dR jA dR dx .' dR dy lx dR dz Jj

-dt = -v— -i—dt+ -j- ~-dt+ -f--r- dt
da da: da ay da dz da

dR dx'± dR dyf Jx dR dz' lA

+ -tj i—di + -~n i dt+ "37/ j- du
dr da dy da dz' da

But if, as in the planetary theory, &c, R does not contain

x, y\ d explicitly,

dR dR _ dR _

dxl dy1 " dzf

dR lt dR dx Tj dR dy Jt dR dz 7, ,■• „

— — dt = -5 -j- dt+-j -f- dt+-T-~ -?—dt (1.)

da dx da dy da dz da x '

The following equations result from the usual conditions,
... . dx dy dz . . .

namely, that the expressions ttt* ~7n~9 ~j7 contlnue inform

the same in disturbed as in the undisturbed motion. See the
Mecanique Anal., torn. i. p. 330.

dx , dx ./" dx j dx , Q •■ ,« \

-=— da + — rrdo+-r- dc + s— de + &c. = 0 (2.)

da do dc de v '

&dafQ;dHM&+Mde+kcSmO (3.)

da db dc de v '

dz j dz ,, dz j dz , i 0 ^ ..

-j— da+-Tirdb+-r—dc+ -j- d.e + 8cc. = 0 (4.)

da db dc de x '

Also,
rf^ _ dfa' ,, , rf^ , , dx1 dR '. .

494? Mr. Lubbock on the Variation of the

^-da + d£db+ &dc+*£ *< + **.= -*£** (6.)
da db dc de dy v '

dz' , dz* .. dz' dz dR

-i—da+ -n-db+—r~dc+-r- de + &c.= r- dt (7.)

da db dc de dz v

Multiplying (2) by ~, (3) by ^-, (4) by ~~ and

adding the equations so formed to equation 1, after having

substituted in (1.) the values of -T— , -^ — and —j— from
v ax ay dz

(5), (6) and (7), I obtain the equation

dR , __ ( dx dx' dx* dx dy dy' dy' dy

da \ da da da da da da da da

+

dz dz' dz' dz \ ,
da da da da f

C dx dx'
\~db lU

( dx

dx' dx dy di/ dy' dy
db da db da db da

diss dz' dz1 dz \ , .

db da ab da y

dx' dx' dx dy dy' dy' dy
~~da~ dc da dc da dc da

dz dz' dz' dz "\ r
dc da dc da J
+ &c.

= (b, a) db + (c9 a) dc 4- (e, a) de + &c. (I.)

which is Lagrange's theorem. Again,

dV _ dV_ dx d£dy_ dV dz
da ' dx da dy da dz da

dx' dx dy' dy dz dz

dt da dt da dt da

(8.)

Similarly
dV

f

dx1 dx

dy dy

dz dz

db

dt db

dt db

dt db

dt db dt db ^

differentiating (8) with regard to b and (9) with regard to a9
and subtracting one result from the other, M. Cauchy obtains
the equation

d (b» a) /T\

j. =0 (b, a) = constant.

a t

See Liouville's Journal, Oct. 1837, p. 407.

Arbitrary Constants in Mechanical Problems. 4-95

Finally, if in the equations

d a — [b, a] -TV- d t— [c, a] -7— */ £ -f &c. = 0,

the values of —rj- dt, —, — dt, &c. are substituted from the
db dc

equations which constitute the 1st theorem, viz.
— — dt = (a, b) da + {c,b)dc -f (c,b) de +&c.

— — dt = (a, c) d a + (b, c) d b + (e, c) d e + &c,

CL C

the resulting equation must be identically equal to zero; and
equating to zero separately the coefficients of da, db, de, &c.
in this equation, I obtain the equations

1 = [b, a~] (a, b) -f [c, a] {a, c) + [a, c] (a, e) + &c. (10.)

[c, a] (b, c) + [c, a] (b, e) + &c. = 0 (11.)

[b,a] (c,b) -f [c,a] {c,e) +&c. = 0 (12.)

These equations are given by M. Cauchy in Liouville's
Journal de Mathematiques, 1837, p. 409; but the proof which
M. Cauchy has there offered is in my opinion .by no means so
.simple as the foregoing. These equations serve to connect
the quantities [b, a], \c, a~], &c. with the quantities (b, a), (c, a),
&c, so that by elimination the one may be deduced from the
other, and they serve to show that these quantities \b,a~], [c,a~\,
&c. are also constant, and independent of the time.

The reasoning which is required to establish the principal
theorems I, II and III, is the same in the case of only one vari-
able x, and of one differential equation, with two arbitrary con-
stants a and b tf x dV dR

4- -1 = 0

df : dx T dx

as in the more general case of three variables x, y, z, with
six arbitrary constants.

I have written this short paper under the impression that
the proof here given of Lagrange's theorem (Theorem I.,
p. 4-94-,) and the proof given here of equations (10), (11), and
(12), have not been presented before; but these methods are
extremely simple that it is by no means unlikely that they
have occurred to others who may also have sought to bring
this important theory within a narrower compass and within
the reach of more elementary considerations than those
hitherto employed.

[ 496 ]

LXX. Remarks on M. Mossotti's Theory of Physics, suggest-
ed by Mr. Babbage's notice of the same. By Mr. Thomas
Exley, M.A.*

T^HERE is most certainly one theory of physics, and only
-*- one ; to determine this has always been the aim of philoso-
phers. Innumerable have been the theories proposed, and as
often have they been refuted, or at least rendered doubtful,
till Newton unfolded the laws of gravitation ; his doctrine has
stood every test, and cannot be overthrown : but his theory of
gravitation does not embrace molecular action. Many have at-
tempted the generalization without success; and this paper is
intended to show that even the theory lately proposed by
Mossottif, or any similar theory, which continues the direction
of the forces the same to the centres of atoms, cannot be true.
This so far clears the way for my own, which the more I ex-
amine the more I am convinced is the true one; which also it
is desirable to corroborate. Because my theory is in conformity
with received principles, with the single difference of a change
of direction of the force, near the centre, and because no phae-
nomenon can be found in contradiction to its doctrines, it has
everything in its favour which, previously to its adoption,
any theory can have. But since Mossotti's theory has excited
much attention, and he has endeavoured to support it bjr ma-
thematical reasonings, I have considered it incumbent on me
to investigate its merits, especially as it has been particularly
noticed by so great a name as Mr. Babbage.

While reading note A in Mr. Babbage's Ninth Bridgewater
Treatise, it was gratifying to observe, that a train of thoughts
had occupied my own mind, while writing my New Theory of
Physics eight years ago, very similar to that which runs
through the note mentioned.

Mr. Babbage has given a clear and concise statement of
Mossotti's theory, and several judicious observations on what a
physical theory ought to comprehend ; and as I wish to make
some remarks on that theory, with notices respecting my own,
I beg to present some corresponding sentences from that note
and my own treatise, as the reasons of such remarks; first
stating that Mossotti has, in behalf of his theory, introduced
some profound mathematical investigations: but we must be
aware that such abstruse processes are not to be regarded as

* Communicated by the Author.

t A notice of M. Mossotti's views will be found in Lond. & Edinb. Phil.
Mag , vol. x. p 320 ; and a translation of his entire paper in Scientific Me-
moirs, vol. i. p. 448. — Edit.

Mr. Exley on Mossotti's Theory of Physics, 497

completely conclusive, till established at least in some re-
markable particular cases, as is allowed on all hands, on ac-
count of the hypotheses, substitutions, and omissions of small
quantities in the progress of the reasonings.

The theory is this : M. Mossotti supposes " matter to con-
sist of two sorts, each of which repels its own particles, direct-
ly as the mass, and inversely as the squares of their distances,
while each attracts those of the other kind according to the
same law." Babbage, p. 164.

Mossotti supposes the forces to be directed towards central
solids, which he assumes to be small and spherical ; he also
considers one of the two sorts to be diffused through universal
space, and this sort he calls aether, its elements Mr. Babbage
calls atmospheric particles ; and the other sort, of which com-
mon bodies are formed, Mossotti calls molecules.

The two following principles comprehend my theory ; viz.
1st. Every atom of matter consists of an indefinite sphere of
force, which varies inversely as the square of the distance from
the centre ; and this force acts towards the centre, and is call-
ed attraction, at all distances, except in a small concentric
sphere, in which it acts from the centre, and is there called
repulsion. 2nd. The differences and distinctions of atoms
arise from differences in their absolute forces, and in the
radii of their spheres of repulsion.

According to this theory central solids are unnecessary. It
was observed by the venerable Dr. Dalton (August 23rd,
1836) in a discussion of the subject at the meeting of the
British Association in Bristol, that he could not give up the
idea of solid atoms : my reply was, the theory does not require
it, provided we may have the solids as small as we please ;
in that case they can do neither good nor harm. A very
learned and universally admired professor of Cambridge, who
honoured my paper with some judicious remarks, previously to
its being read on that occasion, objected that " it would be
impossible to identify such a repulsive force with the attractive
force, because the law of continuity would be violated." Now
I humbly conceive we do not in general determine the identity
of a force by its direction, but rather by the law of its action,
which in these principles is continuous. Why may not this
change be at once ? It must appear that all who admit alterna-
tions of attraction and repulsion, must admit such violation, if
it be one, of continuity ; for the change of direction is equally
so, whether it be from a finite to a finite, or from an infinitely
small attraction to an infinitely small repulsion.

It is manifest that this theory provides for an infinity of
sorts of matter, and that the centres of atoms can in no case
coincide. Various sorts of atoms according to the above prin-

ThirdScrics. Vol. 11. No. 70. Dec. 1837. 3.S

498 Mr. Exley's Remarks on M. Mossotti's Theory qf Physics,

ciples may be assumed, and calculations made to deduce the
phenomena a priori; but in order that such phenomena may
agree with those actually observed, we must be guided in such
assumptions by the indications of nature: on this ground I
have admitted three classes: 1st. Tenacious atoms, distin-
guished into sorts by moderate differences in their absolute
forces and spheres of repulsion. 2nd. Electrical atoms, being
such as have a much less absolute force, say a thousand times
less than the least powerful of the first class. 3rd. iEthereal
atoms, whose absolute forces may be several million times less
than those of the 2nd class, and like the first consisting of
several sorts. If we suppose a due quantity of each variety
present, it is manifest that the atoms of the first class will at-
tract to their spheres of repulsion dense atmospheres of electric
and aethereal atoms, whose centres will be found within the
spheres of repulsion of contiguous atoms : and such a body as
the earth will retain an atmosphere of such matter if present ex-
tending several hundred miles, giving rise to such repulsions
as are observed.

Mr. Babbage has presented Mossotti's theory under a mo-
dified form in note A : he says, " If matter be supposed to
consist of two sorts of particles, or rather centres of force, of
different orders of density, and if the particles of each sort re-
pel their own particles according to some given law, but at-
tract particles of the other kind according to another law,
then if we conceive only one particle of the denser kind to
exist, and an infinite number of the other kind, that single
particle will become the centre of a system surrounded by all
the others, which will form an atmosphere around it, denser
nearer the central body."

Mr. Babbage observes, 1st. That one particle of the denser
kind will form around it an atmosphere of the other kind,
when such are present. 2nd. That a stream of the atmospheric
particles being added will increase its magnitude, and produce
undulations, which will continue till it is increased to a certain
extent, when it will begin to radiate. 3rd. " If the whole space
in which such a central particle is placed, is itself full of atmo-
spheric particles, then their density will increase in approaching
the central body." 4th. " If a stream of such particles were
directed towards the centre, they might produce throughout
the atmosphere vibrations, which would be transmitted from
it in all directions." 5th. " If two such central particles, with
their atmospheres, exist at a distance from each other, they
will be drawn together by a force depending on the difference
between the mutual repulsions." Pages 164, 165, 166.

The following, extracted from my New Theory, nearly cor-
respond : 1st. The electric fluid and aethereal matter form at-

suggested by Mr. Babbage's notice of it.

mospheres about the tenacious atoms. Prop. 10. cor. 5 — 10.
2nd. The centres of two tenacious atoms being fixed near
each other, when sethereal matter is added to one of them, its
atmosphere will be increased to a certain degree, and then
transfers will begin to be made to the other, and vibrations will
be produced. Prop. 14. cor. 4?. 3rd. Two or more tenacious
atoms being put into a space containing a large collection of
aethereal atoms, will accumulate atmospheres. And when an at-
mosphere is increased, it will not only be more extended, but its
density at the same distance will be augmented. Prop. 10, 11,
and cor. 5. 4th. Vibrations will be produced in bodies perpen-
dicular to their surfaces, when ethereal matter is added. And
in the composition of bodies multitudes of sethereal particles will
be projected with great force, (will radiate,) and because of their
own minute force, they will move v/ith very great velocity, as
is known in caloric and light. Pages 18, 19, and 63. 5th. The
actions of the aethereal atoms, although in some cases tending to
preserve, will in many cases tend to separate the tenacious
atoms. Prop. 15. cor. 1.

From these quotations it will be seen that I have considered
my theory as possessing all the requisites above stated and
they may be fairly deduced from them ; but this cannot hold
in Mossotti's theory. For let a be the sum of the forces in
two molecules A and B, and let the effective quantity of matter
in the atmosphere of A be equivalent to a quantity of the same
matter placed at its centre, and the like of B's atmosphere ;
and let b represent the sum of these quantities of matter when
A and B are at the distance m, and p b when they are at the
distance n ; also at an unit's distance let the repulsion of A and
B with the atmospheres which they have at the distance m9
be d, and their attraction e ; then with their atmospheres at
the distance n, if the repulsion be qdoX the unit's distance,
the attraction will be q e, because the forces at a given distance
are as the quantities of matter ; hence

— (a+b) is the attraction, and —2 (a+b) is the repulsion, at the distance m

and

?2- (a+b) is the attraction, and l— (a+b) is the repulsion, at the distance n.

Hence at the distance m, the attraction is to the repulsion as
e to d, and at the distance ?i, it is in the same ratio From
this it follows that if at any distance the attraction is equal to
the repulsion, or if it be greater or less than the repulsion, it
will be so at all distances, and therefore Mossotti's theory can-
not be true.

3S2

500 Mr. Exley's Remarks on M. Mossotti's Theory of Physics,

Also from the assumption which Mossotti has introduced
into his calculations, viz. that the elasticity of the aether varies
as the square of its density, the insufficiency of his principles
may be inferred. For the density must be much greater near
the molecules than in free space, because the molecules
powerfully attract the aether, and retain very dense atmo-
spheres : hence also the density of the aether near a large body
of molecules must be much greater than in free space ; con-
sequently its elasticity in free space must be much less than
near the large body, being as the square of the density. But
by his first principles the elasticity in free space must be per-
fect, since all the atoms are within the sphere of each other's
repulsion, and no attraction exists among themselves, so that
whatever displacement is made by a force applied, the atoms
will restore themselves, when the disturbing force is removed,
by a force equal to that by which they were displaced : hence
the elasticity is both perfect and imperfect at the same time,
which is impossible.

It seems as if Mossotti had assumed the universality of his
aether to please the undulationists; but they have no reason
to thank him, because it would completely undo their system,
which is obliged to allow the hypothesis, that the elasticity of
the aethereal medium is more imperfect in bodies than in free
space.

Mr. Babbage further states that " the other conditions to
be satisfied are," 1st. " That the juxtaposition of such atoms
must in some circumstances form a solid body." 2nd. " In
other circumstances a fluid." 3rd. In other cases a gaseous
body—" The solid must possess cohesion, tenacity, malle-
ability, elasticity :" the other forms must possess capillarity,
and susceptibility of compression, without becoming solid, as
also elasticity, p. 166. He adds, 4th. The central atoms
must admit of a more intimate approach, so that their atmo-
spheres may unite, and form one atmosphere. (i Binary com-
pounds might then have atmospheres not quite spherical, thus
possessing polarity." 5th. " Combinations of three or more
atoms, as the central body of one atmosphere, might give great
variety of attractive forces." 6th . " Two or more central atoms
uniting, might either not be able to retain the same amount
of atmosphere, or they might possibly be able to possess a
larger quantity." p. 166. and 167.

Corresponding with these, it will be found in my treatise,
1st. That some bodies will have the solid form; prop. 19.
2nd. Others will have the liquid form ; p. 20. 3rd. And others
the gaseous form ; p. 21. See also pages 60, 93, 103 and 105.
4th. That if two tenacious atoms with their atmospheres be

suggested by Mr. Babbage's notice of it. 501

placed very near each other, in certain cases both will become
enveloped in one atmosphere, and these will have polarity ;
prop. 15. cor. 4. 5th. If three tenacious atoms with their at-
mospheres are placed sufficiently near, they become enveloped
in one atmosphere. Particles composed of three or more atoms
will possess polarity ; prop. 16, and cor. 4. 6th. It will be
found in the explanations of several phenomena, that the com-
binations of two or more atoms may retain more or less aethe-
real matter in their atmospheres than one of them separately;
p. 96 to 100, and 140 to 160.

These several requisites of a good theory are with perfect
ease derivable from my principles ; but some of them are in-
consistent with those of Mossotti, as is easily demonstrable.
It may be said that on the electrical hypothesis of one fluid, as
well as on that of two fluids, bodies will be repelled, or at-
tracted, or held in a state of equilibrium, according to the di-
stance ; but it should be recollected that these hypotheses
have the earth and its atmosphere as a foundation, or as a se-
parate existing matter, and on this ground may be convenient
as far as they go, although not physically true ; but Mossotti's
theory has no such support. If his conclusion from his ma-
thematical investigations were correct, viz. that all distant
molecules attract each other, we have shown they would al-
ways do so, and his theory could not be true ; but we reject
that conclusion, by proving that, according to his principles,
not one of the forms of solids, liquids, or gases could exist.

First conceive that the atoms have no solid centres, then a
molecule plunged into the aether would attract into its own
centre just so many centres of the aethereal atoms as by their
united forces would exactly equal the whole force of the mole-
cule ; therefore the attraction of the compound atom on any
distant atom of either kind would be equal to its repulsion on
the same distant atom : hence the result is neither attraction
nor repulsion. Next let the small central spherical solid be
restored, and the concentrated aether now symmetrically dis-
posed about the solid as an atmosphere ; this atmosphere will
have the same effect on any distant atom as when placed in
the centre (Newt. Prin. B. I. pr. 76.); but this atmosphere is
that which the molecule would acquire when plunged into the
aether, since, as is evident, its atmosphere would increase till
its repulsion on any distant atom is equal to its attraction, and
no more: therefore still its resultant action on any di-
stant atom of either kind is null, and the same is true of any
other molecule; hence, on these principles there could be
neither cohesion nor elasticity, and the forms of bodies, as
solids, liquids or gases could not exist.

502 Mr. Exley's Remarks on M. Mossotti's Theory of Physics,

Mr. Babbage, as above stated, has presented the theory in
a modified form, in which the repulsions are regulated by
some given law, and the attraction by some other given law.
First, let there be no central solids, and take two molecules
A and B, and let one of them, A, be plunged into the aether;
it will, as in the former case, attract the centres of aethereal
atoms into its centre, till just so many are concentrated as are
equal in force to the molecule at its centre: but since the law
of attraction is different from that of repulsion, the actions of
the compound atom, on any distant atom, will be different.
And now let the molecule B, with its concentrated aether, be
placed at a distance from A, and let the molecule A attract
the concentrated atoms of B with the force ft, and let the con-
centrated atoms of A repel the same with the force m ; there-
fore the attraction of the compound atom A on the concen-
trated atoms of B is n—m. Again, because of the equal forces
at the centre, we have the attraction of the concentrated atoms
of A on the molecule B equal to m ; and the repulsion of the
molecule A on that of B is n : therefore the attraction of the
compound atom A on the molecule B is m — n : consequently
the attraction of the compound atom A on the compound
atom B is n — m + m— w = 0, so that two distant atoms neither
attract nor repel. If very small solids be supposed to occupy
the centres, the same will follow; because whatever is the law
of force, the effect on atoms whose distance is great in com-
parison of the diameter of the body, will be the same as if
the atoms were collected in the centre of gravity of the
body (Math. Prin. of Mech. Phil.) ; hence the effect in this
case will be the same as before: therefore according to the
theory thus modified, whatever may be the given laws of force,
no action on distant atoms can result: the theory is therefore
erroneous.

Having thus shown that Mossotti's theory is not the true
one, it may be added, that I have frequently tried my own by
such tests as occurred: it is possible that prejudice may have
had some influence in preventing me from discovering my
own errors, if such there be, in the principles. It would to me
be a kindness if some philosopher would undertake to prove
any defects which he may conceive militate against my
theory : if he show it to be inadequate he should have my sin-
cere thanks, however unexpected and unpleasant it might be
to my views and feelings, as it would save me much expendi-
ture of time and thought, of which, besides property, much
has been devoted to this subject, with a view to the interests
of philosophy, without other emolument : so that should the
theory be proved insufficient it would conduce to my advan-

suggested by Mr. Babbage's notice of it. 503

tage and to that of others ; while, on the other hand, if it be
found that the interests of philosophy have been promoted by
my labours, it will yield me a gratification and pleasure
amply repaying my toils in the field of science.

Permit me to present, by way of conclusion, a brief view of
what I consider to be done, and may, as it seems to me, be
done, by this theory ; first observing that all which remains
in addition to its principles, in order to render every depart-
ment of natural philosophy a mathematical science, is to obtain
approximatively, 1st. A knowledge of the absolute forces of
at least tenacious atoms ; 2nd. The radii of the spheres of re-
pulsion ; 3rd. The quantities of each class and sort. The
first is in a tolerable degree made out in the atomic weights
of elements, which are obviously as the absolute forces, or
masses, since these weights depend simply on the force of the
earth's attraction at a given place. A rude approximation of
the two others may be attained from phaenomena, and the
more accurately as science proceeds. Respecting these three
particulars, the most likely assumptions may be admitted, and
from them calculations instituted, and when these are compared
with actual phaenomena, such alterations may be made, in the
constants assumed, as the results may indicate. It may here
be observed that every phenomenon of physical astronomy is
explicable on this theory, since as far as that elegant science
is concerned, it agrees precisely with that of Newton.

But what greatly raises my expectation in favour of the truth
of the theory is, that, 1st. The general properties of bodies
are derivable from it, as extension, divisibility, mobility, vis
inertiae, &c. 2nd. The laws of motion or of vis inertiae are
necessary consequences. 3rd. The principle, which as the re-
sult of experiment forms the foundation of hydrostatics and
pneumatics, viz. that pressure communicated to a mass of fluid
in equilibrium is equally transmitted through the whole, may
by it be easily proved. 4th. The three forms of bodies, as well
as cohesion, capillary attraction, and the attraction of floating
bodies, with elasticity, tenacity, &c, equally are the offsprings
of these principles. 5th. The polarity of particles in certain
circumstances, and consequently crystallization and chemical
affinity, in like manner result from the same views. 6th. The
same may be said of the important law of the diffusion of gases
and vapours, of Mariotte's law, definite proportions, the theory
of volumes, and the electrical condition of elements. 7th. The
leading phenomena of electricity, galvanism, magnetism,
electro-magnetism, and optics flow freely and clearly from the
same fountain. I am deeply interested in the wish that some
mathematical philosopher would take up the subject. Were I
thirty, instead of almost seventy years of age, I would enter

504- Prof. Kane on the Action of Ammonia

into a full investigation of this theory mathematically : but
now my age forbids ; it remains therefore only for me earnest-
ly to recommend these labours, which I am sure will yield
abundant fruit, to the consideration of the real lovers of
science.
Bristol, Sept. 29th. 1837. Thomas Exley.

LXXI. On the Action of Ammonia on the Protochloride and
Peroxide of Mercury. By Robert Kane, M.D., M.R.I.A.,
Sfc. fyc*

Of the Action of Ammonia on the Protochloride of Mercury,

§ 1. — Action of Liquid Ammonia up o?i Calomel.

HPHE decomposition resulting from the action of water of
ammonia upon the protochloride of mercury, does not ap-
pear to have attracted particular attention, as all writers who
speak at all upon the subject, mention ammonia, along with
potash and soda, as decomposing calomel into black oxide of
mercury. Hennell in particular, states expressly, that calomel
decomposed by excess of ammonia, yields a black powder
containing in 100 parts, 96 of mercury and four of oxygen.
I was therefore rather surprised when experiment showed
me that a reaction of a totally different nature takes place,
giving rise to a compound possessed of very remarkable pro-
perties.

When water of ammonia is poured on calomel, whether
sublimed or precipitated, the mass immediately becomes black,
and the appearance is not altered by boiling the mixture for
along time. While yet wet the powder remains almost black,
but it becomes much lighter on drying, so that when quite
dry it is of a dark-gray. This powder is not altered by ex-
posure to air, or to a moderate heat ; a portion of it was ex-
posed in a platinum crucible on a sand-bath for several hours
to a temperature of 180° Fahrenheit, without being altered in
weight or colour. When moistened it becomes nearly as dark
as when first generated, but it again loses its black colour on
being dried ; boiled with water it does not appear altered in
its composition. When this powder is heated in a tube
sealed at one end, it first gives a trace of water, with much
azote and ammonia; then there sublimes calomel mixed with
metallic mercury, the decomposition being accompanied with
that sort of effervescence which appears in the heating of so
many of the substances under examination.

* From the Trans. Roy. Irish Acad., vol. xvii. p. 441 ; being Sections If.
and III. of the author's "Researches on the Action of Ammonia upon the
Chlorides and Oxides of Mercury;" in continuation from p. 435 of our
last number.

on the Protochloride and Peroxide of Mercury. 505

For the examination of this body, an order of analysis si-
milar to that adopted for white precipitate was pursued.

A.— 148*15 grains of precipitated calomel were boiled for
some minutes with a great excess of water of ammonia, and
the whole thrown on a filter. The black powder thus ob-
tained weighed 141*92 grains corresponding to 95*79 grains
from 100 of calomel.

The liquor that had been filtered off was acidulated by
nitric acid and nitrate of silver added in excess ; the chloride
of silver precipitated was collected and dried: it weighed
44*44 grains corresponding to 30*0 from 100 of calomel; and
the 30*0 grains of chloride of silver containing 7*401. But
calomel consists in 100 parts of

Mercury 85*117

Chlorine 14*883

Therefore we have by this experiment, the black powder
composed of

Mercury 85*117 and 88*85

Chlorine 7*482 7*76

Other matters . . 3*191 3-39

95*790 100*00

No. 2. — 153*36 grains of calomel were boiled with water of
ammonia for a few minutes, and filtered. The dry dark-gray
powder weighed 146*71 grains, corresponding to 95*66 per
cent.

The liquor treated with nitrate of silver gave 44*03 of
chloride of silver, corresponding to 28*71 of chloride percent,
and which contains 7*08 of chlorine.
Thus we obtain,

Mercury .... 85*117 or 88*98
Chlorine .... 7*803 8*15

Other matters . 2*740 2*87

95*660 100*00

The mean of these experiments gives,

Mercury .... 88*91
Chlorine .... 7*95
Other matters . . 3*14

100*00

B. — As the above method necessarily throws the chlorine
and mercury estimate rather too high, the following experi-
ment was made, in which the necessary loss produces an op-
posite effect :

101*37 of the powder were boiled with strong muriatic acid,
Third Series. Vol. 1 1. No. 70. Dec. 1837. 3 T

506 Prof. Kane on (he Action of Ammonia

and an acid solution of protochloride of tin added. The re-
duction of the quicksilver took place readily, and large well-
formed globules appeared ; the metal collected and carefully
dried, weighed 89*39 grains, or 100 of the powder had given
88-18.

C. — 51*42 of the gray powder were dissolved in dilute
aqua regia, and a current of sulphuretted hydrogen in excess
passed through the liquor. It was found, that owing to free
chlorine, the sulphur precipitated invalidated the result. The
whole was therefore mixed with nitric acid, and boiled until
the sulphuret of mercury was completely decomposed ; the
liquor was then freed from the particles of pure sulphur and
evaporated until all free nitric acid and chlorine were com-
pletely dissipated. Being then treated by sulphuretted hy-
drogen, it yielded a sulphuret, pure and jet black, which col-
lected and dried, weighed 52*39 grains, consisting of

Sulphur 7-19 1 ,2

Mercury 45-20 J cz **

The 51-42 grains therefore contained 45-20 of mercury
or 100-00 - - - 87*90.

In this experiment so much ammonia was lost by the treat-
ment with nitric acid, that its quantity could not be deter-
mined.

D. — As in none of these former analyses had the ammonia
constituent been determined, the following experiments were
made for the purpose of ascertaining its precise quantity :

1st. 66*43 grains were boiled with an excess of solution of
iodide of potassium, and the flask being connected with a bent
tube dipping into dilute muriatic acid, the heat was kept up
until all the ammonia and about half the water had passed
over. The liquor was then evaporated to dryness, and yield-
ed a residue of 6*96 grs. of sal-ammoniac, consisting of
Muriatic acid . . . 4*73\

Ammonia 2-33J

or 100 of powder gives 3*36 of ammonia.

The action of potash on the gray powder liberates ammonia
likewise ; but it was found so difficult to obtain complete de-
composition that the method was abandoned. Another pro-
cess tried, consisted in repeatedly distilling strong muriatic
acid off the powder, in order to convert it into metallic mer-
cury, corrosive sublimate, and sal-ammoniac, and thus obtain
a quantitative result; but this method also was found of so im-
perfect action, that it could not be well applied.

Summing up the results of the analyses above recorded,
we have for 100 parts of the powder:

on the Protochloride and Peroxide of Mercury. 507

Process.

Mercury.

Chlorine. Ammonia

A

88-91

7*95

B

88-18

C

87-90

D

3-36.

Or the mean result is

Mercury . . .

88-33

Chlorine . . «

7*95

Ammonia . . .

3-36

Loss, &c. . .

0-36

hi 00-00

100-00

It is evident that we have here a body precisely correspond-
ing to white precipitate; the mercury, however, being in pro-
to-combination. Water of ammonia acting on calomel, abs-
tracts half the chlorine, which is replaced by a corresponding
quantity of ammonia in some form of combination. We can
accordingly construct two formulas corresponding to white
precipitate ; in the first, half the mercury being conserved as
protoxidized and combined with an atom of ammonia : in the
second, that half of the mercury being directly united to ami-
dogene. The former theory gives from the formula (Ch + Hg)
+ (Hg+NH3).

Mercury 87*00"

Chlorine 7*59

Oxygen 1-73

Ammonia 3*68_

and 100 of calomel should yield 97*84? of product; whilst the
second, from the formula (Ch + Hg) -f- (NH2+ Hg) gives,

Mercury 88-72]

Chlorine 7'74 M 00*00

Amidogene 3*54<J

and 100 of calomel should yield 95-95 of product, which is
almost precisely the quantity obtained in experiment.

We here find the evidence in favour of the existence of
amidogene in combination to be almost insuperable. I shall
nevertheless retain all through this paper the two methods of
expression, until by examining the compounds of the other
metals, the differences may become so much larger, as to com-
pletely prevent their falling within possible limits of error of
observation.

Of the Action of Ammonia upon Peroxide of Mercury.

The accurate examination of the action of ammonia upon

3 T2

508 Prof. Kane on the Action of Ammonia

peroxide of mercury is of very great importance, as the com-
pound resulting, the ammoniuret of mercury, is one of a very
remarkable class of bodies, viz. the fulminating compounds
containing ammonia; and in addition, the experiments of
Guibourt, the only chemist I believe who has made analyses
of it, would appear to demonstrate in it, a relation between
the number of atoms of ammonia and oxygen, which must in-
fluence the ammoniacal theories to a very great extent. These
circumstances made me trace out the properties of this body
with more exactness than should have been otherwise re-
quired.

I have not been able to prepare a substance possessing the
external characters of the ammoniuret of mercury described
by Fourcroy and Thenard. 1 have varied in every manner I
could imagine, the method of obtaining it; but, although I
got a substance constantly the same in its properties and com-
position, it differed much in appearance from that described
by the French chemists. They state, that by digesting liquid
ammonia on red oxide of mercury during eight or ten days,
the oxide gradually covers itself with a yellowish-white powder
which generally passes to a very fine white. I have never
obtained it of a pure white, but always with a tinge of yellow,
possessing an appearance and affording on analysis, results
always the same. The constancy of its properties justifies me,
I should think, in considering it as pure, notwithstanding its
not exactly agreeing with their result. Unfortunately they
did not publish any quantitative analysis of their product ; the
only one known to me is that in Guibourt's thesis.

In order to prepare ammoniuret of mercury, I precipitated
a solution of sublimate by potash, and the precipitate having
been well washed from all excess of alkali, was put into a bottle
of water of ammonia and left for some days ; its colour became
much lighter, but never completely white. Other portions of
recently precipitated peroxide were boiled in water of ammonia
for a few minutes, until the colour ceased to undergo any
change : the reaction was very much accelerated by heat.
These different portions of product had all the same colour,
and were indifferently, but without mixture, used in the fol-
lowing examination without any difference of properties be-
coming observable.

When this ammoniuret is heated, it gives off much ammonia
and azote; a considerable quantity of water collects in the
tube, and the matter remaining becomes dark-red, like per-
oxide; but if it be allowed to cool, it reassumes its whitish
colour, and is evidently still unaltered ammoniuret. The re-
action evidently does not consist in a separation of the ammo-

on the Protochloride and Peroxide of Mercury. 509

niuret into ammonia and peroxide ; but, from the commence-
ment to the termination, there are disengaged water, ammonia,
azote, oxygen and metallic mercury. The ammoniuret, like
many other mercurial compounds, is dark-red when hot, but
of a whitish colour when cold. When a quantity of the ammo-
niuret is suddenly thrown on ignited coals it explodes very
feebly, and far inferiorly to fulminating gold, with which its
discoverers have compared it : it dissolves readily in nitric or
muriatic acid.

To analyse this compound, processes of a simple nature
were sufficient.

A. — 72*07 grains of ammoniuret were dissolved in muriatic
acid, and the liquor having been diluted was decomposed by
sulphuretted hydrogen. The resulting sulphuret dried and
weighed, amounted to 70*08 grains, consisting of

Sulphur 9*61\

Mercury 60*47 J

The liquor and washings evaporated to dryness, gave sal-
ammoniac, 9*21 grains, consisting of

Muriatic acid 6*28

Ammonia 2*93

Hence, supposing the mercury to exist as peroxide, we have
as the result of the analysis :

Mercury 60*47

Oxygen 4*78

Ammonia 2*93 f

Water and loss 3*89 J

or in one hundred parts —

Mercury 83*90"

Oxygen 6*63

Ammonia 4*07

Water and loss 5*40

2. — The following analysis was made on a portion of am-
moniuret prepared at a different time and in another manner
than that used in the former experiment.

67*57 grains were dissolved in muriatic acid and decom-
posed by a stream of sulphuretted hydrogen. The precipi-
tated sulphuret weighed 65*37 grains, consisting of

Sulphur 8*96\ 7

Mercury 56*41 J 00 '

The liquor evaporated to dryness gave 8*15 grains of sal-
ammoniac, consisting of

Muriatic acid 5*54l

Ammonia 2*61J

72-07

510 Prof. Kane on the Action of Ammonia

we have therefore the result —

Mercury 56*41

Ammonia 2-61 ?

Water and loss . , . . 4*09

or in 100 parts —

Mercury 83*48

Oxygen 6*59

Ammonia 3*86

Water and loss .... 6*07

a result almost identical with the former.

B. — 52*22 grains were dissolved in muriatic acid and de-
composed by chloride of tin. There were obtained 43*74? of
mercury corresponding to 83*76 per cent.

C. — As the constancy of the amount of mercury and am-
monia in the preceding results, proved completely that the
loss did not arise from error, but probably from water pre-
sent, the following experiment was made to ascertain whether
water existed in such quantity : A small green glass retort was
blown, with a pretty long neck ; to it was attached a tube con-
taining potash ; and the ammoniuret in the retort having been
decomposed by a red heat, its gaseous elements were allowed
to escape ; the mercury condensed in the neck of the retort
and the water in the potash-tube ; the result, though not ab-
solutely true, is sufficiently accurate for the determination of
the point required.

Weight of retort and material 75*38

Weight of retort 63*00

Ammoniuret used 12*38 grains
Weight of retort and mercury-residue . 73*35
Weight of retort 63 00

Mercury remaining 10*35

Weight of potash-tube before 278*28

Weight of potash-tube after 278*95

Water absorbed . . 0*67

We thus obtain as results —

Mercury . . . 1035 . 83*62
Water ... *67 . 5*39
Gases and loss . 1*36 . 10*99

But the gases consist of oxygen and ammonia, the former

on the Protochloride and Peroxide of Mercury, 511

being such as to peroxidize the mercury ; and assuming the
remainder to be ammonia without loss, we have,

Mercury

• . •

8362"]

Oxygen

• • •

6-60

kl 00-00

Ammonia

■ . •

4-39

Water

• . •

5-39J

These results summed up, give — >

Process. Mercury.

Oxygen.

Ammonia. Water.

A, No. 1. 83-90

6'63

407 5*40

— No. 2. 83-48

659

3-86 6*07

B 83-76

6*60

C 83*62

6*60

4-39

5-39

)> 100-00

100-00

Giving a mean result of

Mercury 83-68

Oxygen 6 60

Ammonia 4*10

Water 5'62^

on abstracting the water, we have —

Mercury 88-67")

Oxygen 6*99 >

Ammonia 4*34j

The only analysis of this substance that I am aware of ha-
ving been published, is that of Guibourt, already quoted, and
he considers it to be a compound of oxide of mercury and am-
monia in such proportion that the hydrogen of the ammonia
could convert the oxygen of the oxide of mercury into water,
consequently his formula is the following (3 Hg + 2NH3) and
the per centage result :

Mercury 88'08l

Oxygen 6*95 1 100-00

Ammonia 4'97j

with which my analyses may be considered as completely
agreeing. In the abstracts of Guibourt's paper that I have
seen, there is not any notice taken of the water present ; but
yet its constant value shows it to be a chemical ingredient^ and
we have its atomic proportion, thus —

2Hg__405-6_83-68

or nearly

83-68

3H 27 5*57 "' 5-62

The compound (3 Hg + 2 NH3 f 4 H) gives us in per cent,
composition, the following :

Mercury 83*72"

Oxygen 6*60

Ammonia 4'72

Water 4-96^

A result agreeing very closely with that of experiment.

100

512 Mr. Connell on the Nature of Lampic Acid.

Admitting that the azotic element is engaged in the combi-
nation as amidogene, and not as ammonia, the above formula
converts itself into

(2 Hg + (2 NH2 + Hg) + 6 H)

a method of arrangement which we have already met with as
an element of the yellow powder, formed by water on white
precipitate.

LXXII. On the Nature of Lampic Acid, By Arthur
Connell, Esq., F.R.S.E*

I T is well known that Professor Daniell, to whom we are
-* indebted for a knowledge of the properties of this acid
liquid, ultimately came to the conclusion that it is acetic acid
containing some disoxygenating substance which bestows its
property of reducing metallic oxides.

A few years ago I had occasion to examine this acid, as
<well as that resulting from the action of potash on alcohol,
and that obtained by distilling a mixture of alcohol, peroxide
of manganese, and sulphuric acid, and I came to the conclu-
sion that they all contained formic acid besides acetic acid.
The grounds on which the existence of formic acid in them
was inferred, were that they all reduced the oxides and salts
of mercury and silver with effervescence, and that they all were
capable of yielding perfectly well characterised formates of
lead and of magnesiaf.

About the same time M. Leopold Gmelin came by indepen-
dent observation to the same conclusion as myself respecting
the acid from alcohol, oxide of manganese and sulphuric acid| ;
and as the manner in which I had examined the three liquids,
the results which I had obtained, and the conclusions which
I had drawn regarding them, were the same in all the three
cases, I could not avoid regarding M. Gmelin's experiments
as amounting to a verification of the view which I had given
regarding all the three acid liquids.

In a late memoir, however, on the products of the oxida-
tion of alcohol §, M. Liebig once more asserted the peculiar
nature of lampic acid by maintaining that it was " probable,
not to say certain," that lampic acid is identical with a pecu-
liar acid, which this distinguished chemist supposes is formed
by the action of oxide of silver on aldehyde, and to which he
has given the name of the aldehydic. M. Mitscherlich, in the

* Communicated by the Author.

t Edinb. New Phil. Journal, vol. xiv. p. 231.

j Poggend. Anna!., xxviii. 508.

§ Annates de Chim. et de Physique, lix. 289.

Mr. Connell on the Nature of Lampic Acid. 513

last edition of his valuable treatise on chemistry, has adopted
without comment this view of M. Liebig as to the identity of
the properties of these two acids*.

The object of my inquiry is not aldehydic acid. The che-
mical world will gladly receive further light respecting that
acid ; but I think it will not be difficult to show that it will not
be safe in the mean time to receive lampic acid as its repre-
sentative.

It would appear that M. Liebig did not make any experi-
ments himself on lampic acid. He however drew from the
experiments of Messrs. Daniellf and Phillips the following
conclusions, which led him to suppose the identity of the
two acids, and which it will be observed differ in several par-
ticulars from those which these able chemists had themselves
drawn.

" 1st. Lampic acid reduces the salts of mercury and silver
without effervescence.

" 2nd. During this reaction it is changed into acetic acid.

" 3rd. Its atomic weight is the same, or very nearly the
same, as that of acetic acid."

These conclusions shall be examined in their order, after
describing the mode of preparation of the acid liquid.

The acid examined in my former researches on this subject
was prepared by suspending a small piece of ignited spongy
platinum by a fine platinum wire, over aether covered by a
glass funnel, to condense the vapours formed. In the present
case I substituted a coil of fine platinum wire for the piece of
spongy platinum, but no difference was observed in the qua-
lities of the acid obtained. The sulphuric aether was con-
tained in a small evaporating basin which was placed in a
large one. The coil of fine platinum wire was then suspended
by a long wire of the same kind in a large inverted glass
funnel ; and after the coil had been ignited the funnel was
placed in the larger evaporating basin so as to bring the coil
a little way above the surface of the aether. An alembic was
then suspended a little way above the narrow extremity of the
funnel ; and the acid vapour formed was condensed princi-
pally in the funnel, from which it fell back into the large eva-
porating basin, and partly in the alembic head|. The small

* Lehrbuck, i. 159. 3te Auf.

t [The principal results originally obtained by Mr. Daniell were stated
in Phil. Mag., First Series, vol. liii. p. 64.— Edit.]

I When the funnel is large, as from five to six inches' diameter, it should
not be raised, so long as the operation continues, because an explosion is
apt to ensue from the too great access of air, although without injury to
the vessels. On the other hand, when it is smaller it is necessary to place
some thin fragments of glass below its edge, to admit air.

Third Series. Vol.11. No. 70. Dec. 1837. 3 U

514* Mr. Connell on the Nature o/Lampic Acid.

quantity of residual liquid in the smaller evaporating basin
was always thrown away as not consisting of condensed va-
pour. From 2 ounces of aether, which required about 2 J
hours for consumption, rather more than a dram of the con-
centrated acid liquid was usually obtained, and the vessels
were washed out with another dram of distilled water, which
was added to the acid liquid, in whic> state it was employed
in the experiments detailed.

It is unnecessary to say that the liquid thus obtained pos-
sesses powerful acid qualities, reddening vegetable colours
strongly and effervescing briskly with carbonates : and when
we talk of the nature of lampic acid, my understanding of
the expression is that we thereby mean the nature of the acid
thus contained ready formed in the liquid so procured. That
there are other products of an ethereal, oily, or resinous de-
scription contained in the liquid there is no doubt ; but these
are not acids ; and it will be unnecessary to have recourse to
the supposition that they produce or modify the reactions of
the acid which they accompany, if it can be shown that that
acid exerts in its own nature all the characteristic reactions
of the liquid. The examination of these accompanying pro-
ducts did not come within the scope of my inquiry either at
present or formerly.

I. To determine experimentally whether lampic acid re-
duces the salts of silver and mercury without effervescence, a
little of the acid was placed in a tube with solution of proto-
nitrate of mercury, whilst one end of a narrower tube was fitted
into the larger by means of a cork, and the other extremity
terminated in a small quantity of lime-water. On applying
heat to the mixture there was brisk effervescence, precipita-
tion of metallic mercury, and evolution of elastic fluid which
speedily made the lime-water very muddy; and on adding
an acid to the lime-water the muddiness disappeared with ef-
fervescence.

This experiment was repeated, substituting peroxide of
mercury for the protonitrate. Copious effervescence ensued
as before, and evolution of elastic fluid which made the lime-
water muddy; and there was at first on partial cooling a pre-
cipitation of white saline matter, and on the further applica-
tion of heat this disappeared with precipitation of metallic
mercury.

When solution of nitrate of silver was heated with lampic
acid until effervescence and precipitation of metallic silver as
a dark brown powder ensued, and the action was maintained
by the occasional application of heat, the lime-water into which
the evolved gas was conducted became very muddy as before.

Mr. Connell on the 'Nature of Lam pic Acid. 515

With oxide of silver and lampic acid there was, when hea*
was applied, the like effervescence and evolution of carbonic
acid, which made lime-water muddy ; and after the liquid had
been evaporated away on the sand-bath, the residue was me-
tallic silver.

In these circumstances we cannot hesitate to say that lampic
acid reduces the salts and oxides of mercury and silver with
effervescence and evolution of carbonic acid *.

This quality, it is unnecessary to state, is a property of
formic acid. It was also formerly shown that perfectly well
characterised formates of magnesia and of lead may be ob-

* Although it is quite true that Professor Daniell does not state on all
occasions that lampic acid reduces these salts with effervescence, yet it is
equally certain that he nowhere says that it reduces them without effer-
vescence; and M. Liebig appears to have overlooked one or two passages
which seem to prove sufficiently that Mr. Daniell was perfectly aware that
lampic acid reduces these salts with effervescence and evolution of carbonic
acid. After stating (Journ. lnstit.,\o\. vi. p. 323) that lampate of mercury
when heated was reduced with "violent effervescence," he adds, that wishing
to know " the nature of this decomposition of the metallic oxides,'* he
heated black oxide of manganese with lampic acid, and found that carbonic
acid was given off, which precipitated lime water ; an experiment which
I have made with the like result.

A circumstance was observed in the course of my experiments which is
connected with the existence of substances not of an acid nature in the
liquid, and which J shall merely notice for the use of any one who may wish
to make these substances the subject of a separate study. When pure lampic
acid is heated to from 150° to 160° Fahr. an evolution of permanently
elastic fluid commences, and if the heat is gradually increased as occasion
requires, a quantity of permanently elastic fluid is evolved, amounting to nine
or ten times the bulk of the liquid employed. When the gas so evolved
is collected over mercury and washed either with pure water or lime water,
about one sixth of it is absorbed, and the lime water does not become
muddy. The part absorbed appears merely to be vapour either of the
acid or of some aethereal product. The residual gas was found to be in-
flammable, and when analysed in the voltaic eudiometer proved to be
hydrogen nearly quite pure. Conformably with this result it was found
that when the gas evolved from a heated mixture of lampic acid and the
salts or oxides of mercury or silver was collected over mercury, about one
third only of its bulk, and sometimes somewhat less, was absorbed by lime-
water with precipitation of carbonate of lime; and the residue on analysis
proved to be hydrogen. On the other hand, if the acid was first heated
till permanently elastic fluid no longer was evolved, and then mixed with
protonitrate of mercury and again heated, the salt was reduced with effer-
vescence and evolution of carbonic acid without any mixture of inflam-
mable gas. In like manner if the acid was saturated with soda and eva-
porated to dryness, and the salt thus got was redissolved in water, and
mixed with protonitrate of mercury and heated, the salt of mercury was
reduced with evolution of carbonic acid without inflammable gas. The
origin of this hydrogen was not further investigated, because its presence
was evidently altogether unconnected with the properties of the acid con-
tained in the liquid ; these properties being the same whether the liquid
had been previously heated or not.

3 U 2

5 1 6 Mr. Connell on the Nature of Lampic Acid.

tained from the liquid by the proper steps. The salt of mag-
nesia is highly characteristic, and any one who will prepare
it from lampic acid in the manner formerly pointed out, and
compare it with crystallized formate of magnesia, will at once
see the identity. The properties of the salt of lead are also de-
cisive. When the acid liquid was treated in the cold with car-
bonate of lead and left some days, the sparingly soluble salt
of lead gradually precipitated from the liquid. This salt was
then dissolved in water by boiling, and the solution filtered
while hot. On cooling characteristic shining spicular crystals
of formate of lead precipitated. The whole salt produced
by saturating the acid with lead was then treated with alco-
hol at the temperature of 100° Fahr. to take up any acetate
of lead present ; and a portion of the residual salt was heated
with concentrated sulphuric acid. Carbonic acid was evolved
in abundance, and was recognised by its usual properties of
burning with a pale blue flame and being absorbed by heated
potassium.

Of the presence of formic acid in the lampic liquid not a
doubt could therefore exist. To show that it also contained
acetic acid, the alcohol with which the lampic salt had been
treated was examined, after a little saline matter which made
it slightly muddy had subsided and been separated by filtra-
tion, when the alcohol was found to contain dissolved a small
quantity of a salt of lead ; and as the presence of resinous
matter rendered it difficult to examine its properties, a newly
prepared portion of it was treated with diluted sulphuric
acid and distilled. The acid obtained was neutralized with
carbonate of soda, and the solution after being heated to boil-
ing mixed with a hot solution of protonitrate of mercury, when
a copious deposit of shining scales of acetate of mercury took
place, either immediately or on cooling, according to the state
of concentration of the liquid*.

Although the existence of acetic acid in lampic acid was
thus established, yet its quantity was small compared to that
of the formic acid. It was found that the proportion of ace-
tate of lead taken up by the alcohol to that of the undissolved
formate was about 1 to 5; and as the latter salt was much
more free from resinous matter than the former the real pro-
portion of acetic acid was apparently still less than this.

II. We are now in a condition to judge of the accuracy of
the conclusion that in reducing the salts of silver and mer-

• If a hot solution of formate cf soda is mixed in this way with a hot
solution of protonitrate of mercury, an immediate precipitation of metallic
mercury ensues with effervescence j and no white salt is deposited either
immediately or on cooling.

Mr. Conneli on the Nature of Lampic Acid. 517

cury lampic acid is changed into acetic acid. If lampic acid
consists of formic acid with a little acetic acid, it will not re-
quire any argument to show that in reducing metallic salts it
is not changed into the last of these acids. In concluding
that it was so changed, M. Liebig referred to an experiment
described by Mr. Daniell, that when it is heated with peroxide
of mercury, a shining micaceous salt is deposited on cooling,
which he considered to be acetate of. mercury. This experi-
ment I had repeatedly made, and described in my former no-
tice ; and my impression also then was that the precipitated
salt was entirely acetate of mercury; but the conclusion
which both Professor Daniell and myself had drawn from the
experiment was, not that lampic acid had been changed into
acetic acid, but that the acetic acid thus supposed to combine
with protoxide of mercury existed ready formed in the liquid.
From the researches which I have since made, I entertain
no doubt that the salt thus precipitated is to a great extent
formate of mercury. It undoubtedly contains in the form of
acetate all the acetic acid which is present in the liquid ; but
the fact which was formerly overlooked, is that pure formic
acid when heated with peroxide of mercury affords on cooling
a silvery micaceous salt much resembling acetate of mercury.
This fact is not new to chemists * ; and it was further verified
as follows. Crystallized formate of lead prepared with formic
acid obtained by Doebereiner's process from tartaric acid, was
heated with alcohol to take up any acetate of lead which might
by possibility have been present, and was then distilled with half
its weight of sulphuric acid diluted with an equal weight of
water. A portion of the formic acid thus obtained was gently
heated with peroxide of mercury; effervescence ensued, and
on cooling a micaceous shining mass like acetate of mercury
was deposited. When this mass was further strongly heated,
it was reduced to metallic mercury with effervescence. It
was formerly stated that when the white salt which precipi-
tates on cooling, after lampic acid has been moderately heated
with peroxide of mercury, is further strongly heated, it is in
like manner reduced to metallic mercury with effervescence.

To ascertain with still greater precision the nature of this
salt as produced from lampic acid, a portion of it was distilled
with sulphuric acid diluted with twice its bulk of water. The
distilled liquid had a distinct smell of formic acid, and when
heated with peroxide of mercury effervescence ensued, and a
white micaceous deposit was formed on cooling; the salt ex-
amined was therefore principally formate of mercury. Had

* See Gmelin's Handbuch, ii. 125. 3te Auf.

5 1 8 Mr. Connell oil the Nature of Lampic Acid.

it been entirely acetate of mercury, the acid obtained from it
would simply have dissolved the peroxide of mercury.

From all these considerations it is manifest that there are
no grounds for supposing that lampic acid when it reduces
the salts of silver or mercury is converted into acetic acid.

III. The last point relates to the atomic weight of this
acid.

The observations which follow on this subject will, perhaps,
appear to be superfluous to those who may be of opinion that
lampic acid has been shown by sufficiently decisive charac-
ters to consist of known acids. The apparent puzzle on this
point has arisen from the foreign substances contained in the
acid liquid disguising the result obtained, as will be suffi-
ciently evident from what follows. I made an analysis of
lampate of barytes, and at first obtained a result identical with
that of Professor Daniell. The salt was prepared by satura-
ting lampic acid with carbonate of barytes, and was once or
twice alternately dissolved in water and evaporated to dryness.
At each successive evaporation it emitted pungent vapours,
and continued a brownish and partially crystallized mass. It
was then reduced to powder and dried in vacuo over sulphuric
acid. 6*8 grains of the salt thus prepared were dissolved in
water and precipitated by sulphate of soda. The sulphate
of barytes after ignition weighed 6*25 grains, equivalent to
4*1017 of barytes. These data would give as the constituents
of the salt

Acid 2-6983 39*68

Barytes ... 4-1017 60*32

6-8 100*

and 629*4 as the atomic weight of lampic acid, that of acetic
acid being 643*19 and that of formic acid 465*35; but the
brown aspect of the salt was quite sufficient to show that it
was not in a state of purity ; the impurity of course having
the effect of increasing the apparent atomic weight of the
acid. Accordingly it was easy to separate from it a quantity
of brown resinous matter without altering its nature. A
quantity of the salt was kept on the sand-bath at the tempera-
ture of from 300° Fahr. to 320° Fahr. for three quarters of
an hour. By this treatment it became dark brown, and on
solution in water when cold, much dark brown resinous mat-
ter was deposited. The solution separated from this matter
was still coloured and was evaporated to dryness, and the
mass again kept at a similar temperature for several hours.
When again dissolved in water, more resinous matter sepa-
rated, and when again evaporated the mass was still brown.

Mr. Connell on the Nature of Lampic Acid. 519

It was then digested in alcohol for some time under the idea
that more of the resinous matter would be taken up ; but as
the alcohol had dissolved a little of the salt itself and had not
acquired a deep tint, it was evaporated to dryness and the re-
sidue returned to the original mass of the salt. The whole
was again dissolved in water, filtered from a fresh quantity of
resinous matter which separated on the application of heat,
and finally evaporated to dryness. The salt thus obtained,
and which still had a brown colour, was dried in vacuo over
sulphuric acid: 12-34- grains of it thus dried yielded 11*78
grains of sulphate of barytes, which would give the consti-
tuents of the salt as

Acid 4-609 37*36

Barytes 7*731 62*64«

12*34.0 100*

and the atomic weight of lampic acid as 570*7. Thus by the
separation of these successive portions of resinous matter the
apparent atomic weight of the acid had been reduced from
629*4- to 570*7 ; but it was evident that the salt still contained
impurity both from its own brown colour and from that of the
solution separated from the sulphate of barytes in the analysis ;
and it would have required a frequent repetition of the pro-
cess to have approached the true combining proportion of the
acid. This, however, the circumstances did not require
should be done, it being sufficient to show that the atomic
weight was not the same, nor nearly the same, as that of acetic
acid; for little doubt could then remain that the real combi-
ning proportion was that which belongs to the mixture of
known acids of which it is conceived that lampic acid has
been ascertained, by its ordinary reactions, to consist.

Care was taken to establish that the treatment had not
altered the nature of the barytic salt analysed. The soda salt
obtained in the latter analysis, and containing the acid which
had been previously combined with barytes, still reduced
protonitrate of mercury with effervescence and evolution of
carbonic acid on the application of heat ; and by an examina-
tion of the resinous matter which had separated, it was ascer-
tained-that not more than T|^ of the barytes contained in the
salt examined had been separated during the treatment to which
it had been subjected, so that only a very minute quantity of
the salt had been decomposed, if indeed the trace of barytes
separated had not previously been combined with the impurity
itself.

The conclusions to which all my experiments have led are
the following :

520 Mr. Fox on the Temperature of

1st. Lampic acid reduces the salts and oxides of mercury
and silver with effervescence and evolution of carbonic acid
gas ; and it possesses this character in its own nature, and
independently of any matters not of an acid nature by which
it may be accompanied.

2nd. It is obvious from this character, and from the ap-
pearance and properties of its salts, that lampic acid is prin-
cipally formic acid, but mixed with a small quantity of acetic
acid.

In the memoir alluded to, M. Liebig further states, that by
the action of potash on alcohol a small quantity of an organic
acid is produced, the salts of which reduce with the aid of
heat the salts of mercury and silver, without effervescence.
I have here only to repeat what I had previously stated after
a detailed examination of this acid, that according to my ex-
periments it reduces the salts of mercury with effervescence ;
and that this character and the appearance and properties of
its salts show that it is entirely analogous to lampic acid in its
nature. In other words it is formic acid mixed with a little
acetic acid.

In my examination of it, as in that of lampic acid, I was
formerly led to over estimate the proportion of acetic acid
contained in it, from supposing the salt deposited when it is
heated with peroxide of mercury to be acetate of mercury,
whereas I have now little doubt that it really is to a great ex-
tent formate of mercury. From this acid being produced only
in small quantity it is usually examined in a very dilute state,
and on this account the appearance of effervescence when heated
with the salts of mercury occasionally escapes observation.
It so happens that it was the previous examination of this
acid which led me to perceive the nature of lampic acid, as
afterwards experimentally ascertained.
Edinburgh, Sept. 22, 1837.

LXXIII. Substance of a Communication on the Temperature
of some Mines in Cornwall a?id Devonshire, made by Robert
Were Fox, to the Royal Geological Society of Cornwall at
their last Annual Meeting.*

T N the following table I have given the results of observa-
-* tions on the temperature of mines which I have reported
from time to time to the Cornwall Geological Society and
other societies ; and I have selected those experiments only
which were made at or near the deepest parts of the mines

* Communicated by the Author : see our hist Number, p. 480.

some Mines in Cornwall and Devonshire.

521

enumerated, and in which the bulbs of the thermometers
were either buried in the ground or plunged under water, and
into streams gushing into the mines.

References to the letters. — C. Coppermine; T.Tin mine;
L. Lead mine; S. Silver mine; K. "Killas;" G. Granite;
w. Water; r. Rock or ground.

Table.
Mines not exceeding 100 fathoms in depth from the surface.

Ore worked pnpt Depth in Bulb of
in Mines. aoc*- fathoms, thermom. in

Temp.

Date of Ob.

servation.

South HuelTowan... C. ... K.... 45 ... w. ...

60° ...

1822.

Huel Wellington C. ... K.\ Kti

Eastern end of level ... J aU — m '"

58 ...

1827.

Western do. do. ... K. 50 ... w. ...

57 ...

1827.

East Liscomb C. ... 82 ... w. ...

64 ...

1822.

Huel Unity Wood ...T.&C... K. 86 ... w. ...

64 ...

1822.

Huel Unity T.&C... K. 90 ... r. ...

66 ...

1820.

403

369

5 Mines, or 6 Stations : mean depth 67*1 ; mean temp. 61°«5.

Mean temp, of climate 50*

Excess 11-5= l°in35ft.

Mines from 101 to 200 fathoms in depth :

[. ... 120 w.
[. ... 120 w.

B ... 128 w.

Beer Alston ..L.&S. .

Huel Squire C

Chasewater T.&C. "I

Eastern end of deepest level J

Western end of do.

Huel Trumpet T. .

Huel Vor T. .

Tingtang C.

Treskerby C. .

Pol dice, bottom of a \ rp s n

shaft J 1"*u"

Do. do. another

Consolidated mines C. 1

Bottom of a shaft ) '

Do. of another do.

Huel Damsel C.

Huel Alfred \ Q

Eastern end of a level J *
Do. do. "I

Western end of a level J

K.
G.
K.
K.
G.

K.

G.
K.

w.
w.
w.
r.

128
128
139
140
140 w.

144 w.

144 w.

150 w.

150 w.
150 r.

155 w.

66o-5.
68

75

68
65

69

66 ,
76 ,

78 .

80 ,

76

80 ■
70 '.

70

155 w. 67

1822.
1820.

1827-

1827.
1822.
1819.
1820.
1819*

1822.

1822.

1822.

1822.
1820.

1827.
1827.

Carried over

2091

1074-5

* The mean temperature of the climate in a large proportion of the
mining districts of Cornwall and Devon is rather below 50° I believe.

Third Series. Vol. 11. No. 70. Dec. 1837. 3 X

522

Mr. Fox on the Temperature of

Rock.

Depth in

fathoms

Ore worked
in Mines.

Brought over

United Mines C. K. .. 170

Huel Friendship C 170

Bulb of
therm, in

2091

Poldice C.&T.

Ttngtang C. .

Cook>kitchen T.&C

United mines C. .

Huel Abraham C.

Stray Park

Eastern end of level

Western do.

K.
K.
G.
K.

}.

176

178
190
200
200

200
200

w.

Temp.

1074°-5
76
64-5
99

82
68

88

78

72
74

Date of Ob.

servation.

1819.
1822.
1830.
1830.
1815.
1820.
1815.

1827.
1827.

3775 1776
19 Mines, or 24 Stations : mean depth 157"3; mean temp. 74.

Mean temp, of climate .. .. 50 feet.

Excess 24°= Pin 393

If some of the foregoing results, which differ much from
the mean temperature, were omitted, the ratio, instead of 1°
in 39*3 feet, would be 1° in 43 feet, at least.

Mines from 201 to 300 fathoms in depth.

HuelVor T.

Levant ...T.&C.

Dolcoath T.&C.

Bottom of Shaft .,

Near the end of deepest"!

level, thermometer ? [

feet deep in rock, du- f

ring 19 months y j

Bottom of Shaft

Tresavean C. ,

Consolidated mines C. ,

K.

. 209 w. 79° .

. 1830.

G.

. J230 r. 80 .

. 1837.

G.

G.

G.
G.
K.

230

230

239
254

w.
r.

3 feet deep in the rock in a cross level I

and 24 fathoms from the lode J

• In the lode 3 feet deep

290
1972

5 Mines, or 8 Stations : mean depth . . 246*5
Mean temp, of climate

82

76

82
76

85-3

92

652-3

81-5
50

1815.

1822.

1819.
1837.

1837.

1837.

Excess.. . 31°-5 =l°in 47 ft.
or, omitting the last station, at 92° of temperature, the ratio would be 1°
in 48 feet.

If, instead of making the calculation from the surface down-
wards, it had been commenced at 10 or 15 fathoms under
it, where the temperature may be supposed to be nearly
constant, and coincident with the mean temperature of the
climate, it is evident that the diminishing ratio of the aug-
mentation of heat as the depth increased would be rendered
still* more remarkable. On the other hand, the vicinity of

some Mines in Cornwall and Devonshire, 523

metalliferous veins in most of the instances reported, may
have given a rather higher mean temperature than would
have been indicated by experiments confined to rocks at a di-
stance from " lodes." Upon the whole, however, I believe
that the results stated in the foregoing table are sufficiently
near the truth, to prove that the ratio in which the tempera-
ture augments in descending into the earth, is greater in
shallow mines than in deep ones. Moreover, 1 am persuaded
that we have no means at present within our reach to enable
us to arrive at satisfactory conclusions relative to the ratio in
which the temperature of the earth increases at much greater
depths than have yet been attained.

It clearly appears, from what has been stated, that the con-
ducting power of rocks is not the immediate cause of the
high temperature observed in mines ; but the facts are quite
consistent with the hypothesis, which I have long advocated, of
heat being transferred from greater or less depths towards the
surface, in consequence of the well known tendency of warm
water to ascend through cooler portions of that fluid *; and
the anomalous results obtained at equal depths in different
places, often contiguous to each other, are, I conceive, mainly
to be attributed to the greater or less facilities afforded by
the rocks and veins for the circulation of the water.

Note. — The experiments in Levant and Consolidated Mines
marked thus J in the table, were made by burying the bulbs
of long thermometers three feet deep in the rocks, and com-
pared with other thermometers near them buried only an
inch deep. Under these circumstances, the former indicated
about l°\ of temperature more than the latter, proving that
the high temperature was not due to extraneous causes, but
existed in the rock. Such results are, however, only to be
expected in the deepest parts of mines. Indeed, those ob-
tained in the upper levels of mines are generally unsatisfac-
tory and inconclusive, as it respects the native heat of the
earth at equal depths.

[The details of Mr. Fox's observations on the temperature of mines
made from 1815 to 1823, will be found in Mr. Brayley's "Account" of
observations and experiments on the subject in Phil. Mag. First Series
vol. Ixi. p. 348, Ixii. p. 38; and in Phil. Mag. and Annals, N.S., vol. ix.
p. 94, appears another paper by Mr. Fox. See also Phil. Mag., First Series,
vol. xxxiii. p. 320, lxvii. p. 302; and Lond. and Edinb. Phil. Mag. vol. v.
p. 446.— Edtt.]

* To this property of water, and its solvent power at great depths,
where the temperature is very high, 1 believe that many mineral deposits
in veins are to be referred. 1 have stated my views on this subject in the
Royal Cornwall Polytechnic Society's 4th Report, pp. 108 and 109, sold by
Trathan, Falmouth, and Simpkin and Marshall, Stationers' Court, London.

3X2

[ 524 ]

LXXIV. On an alleged Demonstration of Tresnel relative to
the Wave-suiface in the TJieory of Double Refraction, By
John Tovey, Esq,

To the Editors of the Philosophical Magazine and Journal,

Gentlemen,
I AM glad to find from Mr. Lubbock's paper in your last
-*■ Number, p. 417, that he is devoting a portion of his ma-
thematical talents to physical optics. His comparison of
Fresnel's ideas with those which have been since developed
by M. Cauchy and others, is, in the present state of the sci-
ence, of great importance. I hope he will continue these
investigations; and I beg that you will allow me, through the
medium of your Journal, to solicit his consideration of that
part of Fresnel's theory in which it is supposed to be proved
that when the axes of elasticity are taken for the coordinate
axes, the differential equations may be reduced to the form

~j = m *.{ <fr (r) + * (r) Ax*\ A %

Mr. Lubbock takes this point for granted, referring for a
proof of it to the remarks of Fresnel in the Mem, de Vlnstitut.
To these remarks I have no access ; but I conceive that they
can be no more than equivalent to the demonstration of C.J.
in your last volume, p. 24, which only proves, that if one mo-
lecule alone of the system be displaced, it is always possible so
to take the axes of the coordinates that the differential equa-
tions may be reduced to the form

^| = Af.«j{»(r)+*(r)4i'}.

Now this equation is inapplicable when the system is in a
state of undulation; and, therefore, unless it can be proved
that it may then be changed into the form made use of by
Mr. Lubbock, Fresnel's demonstration must be abandoned.

I am, Gentlemen, yours, &c.
Littlemoor, near Clitheroe, John Tovey.
Nov. 6, 1837.

LXXV. A Report of the Progress of Vegetable Physiology
during the Year 18.36. By J. Meyen, Professor of Botany
in the University of Berlin,*

[Continued from p. 446.]
On the Structure and Function of Spiral Tubes,
r I^HAT the spiral tubes in vegetables serve to conduct the
nutritive sap has once more been remarked by Link-j-, in

* From Wiegmann's Archiv fur Naturgcschichtc,\%3'] ', Part 3. Trans-
lated by Mr. Wm. Francis. f Phihs. Bot., p. 189.

Report of the Progress of Vegetable Physiology in 1836. 525

a very distinct manner, and a great number of new data which
he had already made known in earlier writings have been
treated more at large. In reply to those botanists who are
of opinion that the spiral tubes convey air, because they had
observed that air plainly proceeded from them, Link remarks,
that the intestinal canal of animals is also not always full, but
frequently contains air.

Gaudichaud * also has again confirmed a phenomenon,
which had previously been described by various travellers,
and which speaks very determinately for the sap conduction of
the spiral tubes. For if we cut one of these Liane plants
possessing great spiral tubes, and at a time when the sap is
ascending, a great quantity of sap flows out from the surfaces
of the section; that this sap does really proceed from the aper-
tures of the spiral tubes has been observed by myself, and also
by many other persons. Gaudichaud made his experiments on
Cissus hydrophora, a new species which grows in the environs
of Rio de Janeiro. A Liane stem of 15 — 18 lines in diameter
was cut right through ; the surfaces of the section were moist,
no water ran out, excepting a few drops which fell from the
upper surface. A small portion of from 15 to 18 inches was cut
off' from the basis of the upper end, and placed in a vertical di-
rection, and immediately clear water came out in great quan-
tity ; various sections from the lower end of the stem exhibited
the same phenomenon. The flowing out of the sap however
proceeded more slowly ; it just trickled down from both ends,
as soon as the severed portion of the end was held in a hori-
zontal direction. A portion of 15 inches long byfrom 14 to 15
in diameter was cut off from another stem of the same plant ;
this gave two ounces of water. From a second piece of the
same length from the upper end of the stem Gaudichaud ob-
tained rather less water; and this diminution in the flow of
water became the more considerable the further the severed
end was situated from the base of the stem. On the day fol-
lowing that on which the stem had been cut, the surface of
the section of the lower end, which was still standing in the
ground, exhibited no efflux of sap: the whole end from 5 to 6
inches below the surface of the section was dry. Gaudichaud
also takes this occasion to mention the causes of the ascent of
the sap in general ; he thinks it possible to divide the forces
which cause this phenomenon of vegetable life into external
and internal forces. To the external forces would belong
atmospheric pressure, heat, solar light, &c. The internal
forces would have to be subdivided into nutritive and secretive

* Observ. sur V Ascension de la Seve dans une Liane, et Description de cctte
nouvellc cspecc de Cissus. — Ann. des Scien. Nat.

526 Prof. Meyen's Report of the Progress of

forces : to the first would belong the reception of saps and of
gases, the combination of gases with one another, the meta-
morphosis of the gases into liquids, the change of fluids into
solid substances; to the latter, on the other hand, would be-
long the exhaling of gases, liquids, &c.

A memoir by Girou de Buzareingues* has attracted espe-
cial notice; it treats exclusively of the organs of the motion
of sap in plants. The results of this work are so at variance
with those of all other vegetable physiologists that we may-
perhaps expect a full refutation of them ; however, the re-
stricted limits of this report do not allow us to give more than
a general review of it. It will be very easy for all botanists who
have especially occupied themselves for many years with ve-
getable anatomy, to convince themselves that the observations
reported by Girou de Buzareingues on the organs of the motion
of sap do not all agree with nature. The observations it is true
were made with an excellent microscope of Amici; but we
must not however ascribe the faults which had crept into this
work to the instrument, for I, who am also in possession of a
similar instrument, see the objects quite otherwise than Girou
has described and figured them. The chief blame of the dis-
cordant results of these observations might be ascribed to
the mode of observation; for it appears that Girou always
pressed the objects between plates of glass, and observed them
in a pressed condition. We cannot sufficiently warn natu-
ralists against the application of such pressure in microsco-
pical observations.

Girou commences his memoir with the expression that the
sap in plants ascends from the roots to the leaves, and passes
from these again to the roots; that it moves from the axis to
the periphery, and from this to the axis ; and that there is a
gaseous fluid which accompanies this sap. For the effecting
of this motion of the sap the plants employ cells and vessels,
and these are intercellular vessels to and off-carrying vessels.
The intercellular passages (des conduits inter-utriculaires) are
separate vessels, which are said to cause the movement of the
fluids and gases in all directions (even an explanatory drawing
is given in fig. 16. pi. vii. !). To the adducent vessels belong
the simple vessels (des vaisseaux jmis), by which are probably
meant the fibrous cells and the tubes of the liber; and,
further, the spiral tubes or tracheae : to the red ucent vessels
belong, on the other hand, the false spiral tubes.

The fibre which forms the spiral tube is said to be hollow

* Mem. sur laDistribut'ion et 1e Mouvement dcs Fluides dans lex riantcs. —
Ann. dcs Scienc. Nat. 1836. i. p. 226—248.

Vegetable Physiology for the Year 1836. 527

and to convey sap ; it is further stated to be wound round a
delicate tube, and to be inclosed externally by a membrane,
under which is the fluid; while the inner tube round which
the spiral fibre runs is said to convey air only.

These are, properly speaking, the results of Girou's obser-
vations; he however in this memoir as well as in his preceding
ones never specifies the name of the plants on which he made
this or that observation, and on which the observation might
easily be repeated. He also never takes notice of the obser-
vations of other botanists. Towards the end of the paper Girou
{I. c. p. 245) comes to the conclusion, that a certain circula-
tion exists in plants ; the sap ascends by means of the inter-
cellular passages through the whole plant; it is conveyed by
the adducent vessels from the root to the leaves, where it
undergoes an elaboration, and it then passes into the vessels
which carry it off. The sap which is contained in the spiral
fibre of these vessels may descend to the root, and there in the
earth serve for the purpose of excretion ; but the other sap,
which runs between the two membranes of the downward
conveying vessels, is said to flow through the side apertures
into the intercellular passages, and there mix with the ascend-
ing sap. I am very sorry to say that I could convince my-
self of none of these positions !

We will examine more specially the position, that the
spiral fibre is hollow, for although we endeavoured many
years ago to show that this question was decided in a most
definite manner, yet many of the most learned phytotomists
have in these latter years contended for the presence of a ca-
vity in the spiral fibre ; not only Mirbel, but also Link in
his recent work. The latter considers it to be hollow, on ac-
count of some (as it appears) swollen places, as also from its
appearance at the points of ramification. Link*, however,
does not lay much stress on this opinion.

Mohl t has also argued against the presence of a cavity in
the spiral fibre which Mirbel had assigned to the fibre in the
ringed tubes of the Oleander; he says: " If the section passes
exactly through the axis of the vessel, and still better, if we
succeed in obtaining a thin disc-like diagonal section of the
spiral fibre, we can very plainly observe that the spiral fibre
consists of two layers, as it were of a central column and of
a sheath. There is therefore a difference between the spiral
fibre and the fibres of the dotted cells ; but there is also a
similarity, since it is probable that the central column is
the first-formed part of the fibre, and the sheath a later de-

* Elem. Philos. Bot., p. 159. f On Vegetable Substance, p. 29.

528 Prof. Meyen's Report of the Progress of

position on the same ; I however consider thus much

as certain, that the spiral fibre is not hollow." All that
is here said of the fibre of the spiral tubes I also assign
to the spiral fibres which are evident in the interior of the
common parenchymatous cells; for I consider these forma-
tions as identical. I have also in my recent work on vege-
table physiology* enumerated many other reasons which prove
in the most distinct manner that the spiral fibre is always
solid. At times it is thickened by a deposition of new layers
and exhibits at times an apparent membrification.

On Observations respecting the System of Circulation in
Vegetables,

It has been the lot of the doctrine of the peculiar system of
circulation in the more perfect plants in the course of the last
year again to sustain considerable attacks.

Linkf endeavours to demonstrate by observations that the
resinous ducts of the Conifera should be enumerated, in one
and the same class of formations, with the milk vessels of
the Eupho?-biacea? and Asclepiadea? ; although not exactly si-
milar to one another. In young germinating Conifers Link
observed near the resinous passages a peculiar membrane;
but he himself says that in the greater and older vessels of this
kind they seem to disappear. I have hitherto not been able
to convince myself of the presence of the peculiar membrane
of the resinous ducts, and even the drawings of diagonal sec-
tions which Link J has given to these resinous ducts exhibit
no trace of a peculiar epidermis. Much easier is it to ob-
serve the origin of these resinous ducts in the young shoots of
Conifera?; here at least we can say with certainty that these
resinous passages, even in their young state, possess no pecu-
liar membrane; nay, even the leaves of the Coniferce (par-
ticularly the leaves ofPinus sylvestris) exhibit a layer of pe-
culiar cells which form the resinous duct, but no distinct
simple membrane. In the paper quoted, Link advances the
opinion (p. ] 32) that the resinous sap which fills those re-
sinous ducts in the Conifers, appears to be in motion, for the
substance flows out in great quantity and for a long time when
a branch is cut off. It would certainly be a great acquisition
to vegetable physiology if we could more strictly prove this
opinion ; but this is scarcely possible, since the vegetable parts

[* See Bibliographical Bulletin, p. 481 of the present volume. — Edit.]

f Element. Phil. Bot., i. p. 196.

\ Anatomie (Vune Branche de Pinus Strobus. — Ann. des Scien.Nat., 1836.
i. p. 129. PI. iii. fig. 1. — Also in his Anat. Bot. Adbildungen, Tab. vii.
fig. 1 and 5.

Vegetable Physiology for the Year 18S6. 529

which contain such vessels are a great deal too thick to be
immediately observed without any dissecting. Such a motion
of the resin would place the receptacles nearer to the true
vital sap vessels; and I consider it as highly probable that
they are of an importance much greater than we have hitherto
dared to ascribe to them ; for the resinous ducts in the Conifer ce,
as well as the gummy ducts in the Cycadece, form a system,
of itself entire, and perhaps continuous through the whole
plant; and it is exactly in those plants where these resinous
ducts occur that the vital sap-vessels are wanting. A great
coincidence may also frequently be proved, between the saps
of the gummy passages and the vital sap-vessels of various
plants, in a chemical point of view.

Link remarks on the milk vessels of the Euphorbiacece and
Asclepiadece, that they stand singly in the stem, are straight
and simple, and appear ramified only in the young stems
where they run out towards the leaves ; they were also observed
in shrubby Euphorbia with spreading branches; sometimes
they keep on their course at some distance from the nerves.
Link further says that they terminate with an obtuse point;
they also exhibit no anastomoses, nay at times they appear to
have transverse partitions, but only false ones. These obser-
vations, it is true, do not exactly coincide with those which
I mentioned in the report for 1835, with a view to refute the
objections of Treviranus. I yet hope to succeed in giving to
many of them quite a different bearing. In no plant is it more
easy to observe than in the leaves ofHoya carnosa that the ra-
mified and very thick membranaceous vessels with obtuse ends
traverse the diachyma ; these vessels, however, are not milk-
sap vessels, but they are ramified cells of the liber, or fibrous
vessels of which hitherto no mention has been made in botanical
writings. A structure so highly remarkable belongs to the
fibrous vessels (fibrous cells) of the Asclepiadece and Apocynea,
of which mention has already been made. But nowhere is the
ramification and anastomosis of the vessels of the stem to be
observed more evidently and frequently than in the stem of
the old genus Sarcostemjna ; here we find the regular and
manifold anastomosing tissue of the milk vessels deposited
immediately before the layer of the cells of the liber, which
exhibit in every respect one and the same structure with those
ramified vessels in the leaves of the Hoya, with the exception
that ramification is wanting in them. These observations
evidently show in the most certain manner that Mirbel's state-
ment* that the cells of the liber in Nerium, where the ap-

* Vide our Year's Report for 1835.
Third Series. Vol. 1 1. No. 70. Dec. 1837. 3 Y

530 Prof. Meyen's Report of the Progress of

pearance is quite similar, are to be considered as milk ves-
sels, cannot be right. I have not yet been able to succeed
in observing in Ficus elastica the closed ends of* the milk
vessels, neither could I see partitions in these vessels; but
I have seen real anastomoses, even in Chclidonium majus
and in many others.

That the sap in the milk vessels moves had already been
previously confirmed by Link, and it has again been observed
by him ; and he most admirably remarks, that this motion is
neither effected by the contraction of the vessels, nor by the
motion of the molecules contained in the sap, since obser-
vation does not show it.

From various travellers* who have remained for some time in
Columbia, several notices have appeared, from which it is pro-
bable that in the districts in question there occur many other
kinds of trees which produce a milk similar to that of the cele-
brated Cow-tree f, respecting which von Humboldt has in the
accounts of his Travels (chap. xvi. and xxvi.) given us such
highly interesting communications.

Mornay has again diffused through the medium of the
journals very interesting notices on Euphorbia phosphor esc ens,
with the inflammable milk This shrub grows near St. Fran-
cisco in Alagoas in Brazil, in impenetrable thickets, covering,
perhaps, more than 1000 square feet. According to the
statement of the natives, it sets light to itself, throws out for
a long time an immense column of dense smoke, and finally
breaks out into bright flames %.

On the Secretory Organs of Vegetables,

L. Griesselich§ has with great propriety addressed some
admonitory hints to vegetable physiologists on the subject of
our defective knowledge relative to the structure and import-
ance of glands ; he also observes that even what De Candolle
has reported in his celebrated physiological works is unfor-
tunately not adapted for throwing any light on this subject.
He also cites various passages from those works which satis-
factorily prove this. Griesselich's statements respecting this
subject are, however, not founded, any more than De Can-
dolle's, upon personal observations with the compound micro-
scope ; if, therefore, there is nothing new in the memoir, yet
it has the merit of having directed attention to a subject so

» Loudon's Gardener's Magazine, 1836. No. 71, p. 100.

t [See Sir R. K. Porter's description of this remarkable tree in the present
volume of Phil. Mag., p. 452. — Edit.]

\ [Mr. Mornay's first notice of this plant will be found in Phil. Mag.,
First Series, vol. xlviii., p. 423. — Edit.]

§ On the Glands on the Leaves of the Labiataz, and on the odoriferous
constituent parts occurring in them.— Botanical Papers, part i. Carlsruhe,
1836. 8vo.

Vegetable Physiology for the Year 1836. 531

much neglected. The Royal Society of Sciences of Gottingenj
sensible also of the defective state of our knowledge of vege-
table glands, has chosen this subject for a prize question,
which I have endeavoured to answer*.

Griesselich names the oil-bearing glands which occur so
frequently in (not on) the substance of the leaves of the La-
biatte, pores; a term not particularly to be praised, as it might
cause a confusion of ideas, and, secondly, it must be placed
after those which we already possess. Together with Guet-
tard's denomination (glandcs vesiculates), the name, internal
glands, has been used by many phytotomists ; this is very pro-
per, and therefore should be retained, for this is the only kind
of compound glands which occur in the cellular tissue of
plants. Griesselich considers these inner glands as mere re-
ceptacles of a secreted substance, a view which is refuted by
the anatomical examination of them. What is said on the
occurrence of internal glands in Labiatce has already been
mentioned by Guettardf; nay, the latter has written much
more on this subject than will be found in the paper now be-
fore us ; unfortunately, however, Guettard's memoir has re-
mained almost unknown.

JLabiatcc cultivated in gardens contain, according to Griesse-
lich's observations, fewer internal glands than wild species ;
this however can only relate to a smaller production of the
secreted oils; the glands are present in as large a number.
Guettard had already remarked, that in many of these plants
we could observe such glands in dried specimens which in a
fresh state exhibited none.

Besides these internal glands, we find also external, but
simple glands, in the Labiata?, which I have mentioned in the
Gottingen prize essay.

On the Reception of Sap, the Secretion and Nutrition of
Vegetables.

Many very interesting experiments have been made on the
nutrition of vegetables; and it is to be hoped that we may
soon arrive at definite and generally received views on this
subject also. UngerJ for one, has given a very complete
enumeration and comparison of the experiments and views of
botanists and chemists who have treated on the reception and
the formation of the nutritive substance in vegetables. The
question, in fact, is, whether the vital principle of the plant is
of itself capable of forming the organic substances which serve

* Meyen, On the Secretory Organs of Plants. Berlin, 1837. 4to. With
9 tab. of microscopical drawings.

f Observations sur les Plantes. Paris, 1757- 2 vol. 8vo.

% Influence of the Soil on the Diffusion ofPlants. Vienna,! 836, p, 125,&c.:
[See our present Number, p. 564. — Edit.]

3 Y2

532 Prof. Meyen's Report of the Progress of

to nourish the plant ; or whether these nutritive substances are
taken up, at least in their elements, from without. Unger
(/. c. p. 136) finally arrives at the conclusion, " that the pro-
cess of vegetation is neither able to produce new elementary
substances out of the substances presented to it, nor even to
arrange those already present ; from this, however, it imme-
diately follows indirectly, that plants also must necessarily
take up their inorganic substances, such as carbon, hydrogen,
oxygen, and nitrogen, from the external world."

Jablonski * has once more endeavoured to prove by ac-
curate experiments, that the inorganic substances which plants
contain are received from without. In order to refute the
well known experiments of Schrader, which were to prove
from observations that the process of vegetation was able to
form alkalies, earths and metals, Jablonski performed similar
experiments, which afforded the following result. The flowers
of sulphur, which were also employed in these observations,
were purified before the experiments by digesting them in
muriatic acid, and it was proved by this operation that a
quantity of oxide of iron, silica and lime was mixed with the
flowers of sulphur ! In perfectly clean flowers of sulphur,
the seeds of various plants were sown, but they attained only
a very low state of development, even when they were watered
with water containing carbonic acid. The Dicotyledones de-
veloped slowly their cotyledons, but the plumula exhibited no
inclination to lengthen itself; and after from three to four
weeks, all the plants were dead.

Jablonski then made the same experiments with flowers of
sulphur purchased as pure from a druggist; these on being
burnt left behind 4 per cent, of a carbonaceous mass which
gave 1 J per cent, of ashes, of oxide of iron, lime and silica.
Cabbage seeds which were sown in these flowers of sulphur
soon germinated, and attained a height of 4 inches above the
sulphur, till at last they died between the 7th and 10th week,
without having increased within the three latter weeks in any
perceptible degree. This last experiment terminated exactly
in the same way as the experiments of Lassaignes, whose plants
of buckwheat in cleansed sulphur put forth in fifteen days
stems six centimetres high. Lassaignes at that time analysed
the plants thus sown, and found their ashes to have exactly the
same composition with a quantity of the seed equal to that
from which the plants had grown, f

• Contribution to the solution of the question, whether by the process
of vegetation bodies chemically indecomposable can be formed? — Wieg-
mann's Archiv, 1836, p. 206—212.

[f The entire series of researches on this subject recited above bears
importantly on that of Mr. Reade's paper on the solid materials of the
ashes of plants, in our last Number, p. 413,—Edit.]

Vegetable Physiology for the Year 1836. 533

Jablonski draws from his experiments the conclusion that
the plants continued to live only so long as the nutritive sub-
stances deposited in the albumen or in the cotyledons could
go through the chemical process necessary to vegetable life ;
as soon however as their combinations had arrived at a rela-
tive chemical neutrality, death was inevitable, and carbonic
acid and water did not appear to be adapted to the sustenance
of the new product from the organic substances.

From these observations we come immediately to those
which have been made on the reception of various substances
by the roots of plants. Mr. G. Towers* has once more made
some experiments in order to ascertain whether coloured fluids
can be taken up by the roots in their natural state ; but nei-
ther infusions of log-wood nor of Brazil wood were absorbed
by the plant, and this served to confirm the observations of
Link and other German botanists. Towers employed for
these experiments plants of balsam ; and soon after Ungerf
made similar experiments on Lemna minor, which he grew in
tincture of cochineal, with and without an addition of alum, and
in an infusion of log-wood, but he could never observe the
reception of the coloured fluid. The Bibliotheque Universelle
de Geneve% gave an extract from Towers' s experiments, and
complains that he had paid no attention to the labours of
preceding naturalists, who had proved that plants, even with
their roots in the natural state, did take up coloured fluids.
The observations of De Candolle, sen., are here mentioned,
according to which coloured liquids had penetrated through
the spongioles. However these imperfect notices of De
Candolle are contrary to a vast number of negative observa-
tions which I, among others, have performed yearly. But
already, long before the appearance of De Candolle' s Phy-
siology, H. Schultz of Berlin had made known that he had
observed coloured liquid imbibed by a Chara, The obser-
vation is related in a very detailed manner ; yet I have never
been successful in repeating it, although I have made similar
experiments with a great quantity of Chara. Setting aside
this single case observed by Schultz in Chara, we are able to
infer, from unexceptionable observations which we possess,
that the colouring substance in the coloured fluids is not finely
enough divided to pass through the cellular tissue of vege-
tables, and that hence it is not taken up by the plant when
uninjured. On the other hand, it has been proved by various

• Transact, of the Horticult. Soc. of London, Sec. Ser. vol. ii. Part I.
p. 41. — Bibliotheque Universelle de Geneve, No. 5, 1836. — Ann. de* Scien.
Nat., 1836, ii. p. 228.— Froriep's Notizen, No. 1078, Sept. 1836.

f Influence of Soil on Diff". of Plants, p. 149.

; Nouv. Ser. vol. i. Mai 1836-.

534 Prof. Meyen's Report of the Progress of

experiments that substances perfectly dissolved, as for instance
solutions of salts, even if they are the most deadly poisons,
pass through the cellular tissue of plants. Towers and Un-
ger have also performed various experiments as to this point;
the first watered balsams with a solution of iron in muriatic
acid, and although this had entered the plant, yet even after
sixteen days the plant had not at all suffered. It is well known
that Link had previously performed similar experiments with
prussiate of potash and sulphate of iron, ami obtained the
same results ; and Treviranus has, quite without reason,
called in question those results of Link's experiments ; for I
have also succeeded with many experiments of the same kind,
in obtaining similar results.

Towers placed also several balsams with the roots cut off in
the solution of iron, and found that they soon died in it, a re-
sult which was also well known from earlier experiments of
German botanists. Towers concludes from his experiments
that plants in their natural state can take up a substance
without injury, which under other circumstances causes death :
this conclusion is however too hasty, as Unger's more com-
plete experiments have demonstrated; these will be given
below.

Thos. And. Knight* endeavours to call in question the
opinion that the spongioles of the root are the organs which
imbibe the nutritive sap from the soil, and send it forward to
the other parts of the plant: they were too imperfectly or-
ganized. Knight says that he had shown that the nutritive
sap in trees ascends only through the young wood or alburnum,
and since the spongioles of the root possess no woody fibre, it
must evidently be other canals, &c. which take up the sap ;
besides, the young wood is formed very early, long before
the stem and branches are developed. He is convinced that
portions of alburnous fibre have been erroneously supposed
in the spongioles of the root. (The author here probably
alludes to the observations of De Candolle !) It is true we
are still in want of an accurate demonstration of the connec-
tion of the spongioles of the root with those elementary organs
which convey the sap taken up by them onwards; but that the
spongioles of the root, where they are present, take up the
nutritive sap in the same manner as the finest fibres of the
root, is a fact that can no longer be called in question.

Unger (1. c. p. 14-7) grew several plants of Lemna minor

* Upon the supposed absorbent powers of the cellular points, or spon-
gioles, of the roots of trees, and other plants. Trans, of the Horticult. Soc.
of London, Sec. Ser. vol. ii. p. 117, [or Lond. and Edinb. Phil. Mag., vol. x.
p. 488.1 I was obliged to make use of the French translation, the English
original not having yet arrived at Berlin.

Vegetable Physiology for the Year 1836. 535

in four ounces of water in which three grains of sugar of lead
were dissolved; so soon as on the eighth day they became paler,
and here the decoloration began from the root. From the
third day these plants were placed in pure water, but the poi-
soning was so complete that they began to die as early as the
fifth day. Repeated experiments showed that even within
twenty-four hours so considerable a quantity of the salt of lead
had been imbibed that sulphuret of ammonia indicated the
presence of the metal by the brown tint. It was thus proved
that in Lemna not only the little roots imbibe but also the
leaves, and indeed the under surface in as high a degree as
the upper one. This phenomenon is, however, as I think,
quite common, even in the most perfect terrestrial plants, in a
higher degree, however, in the imperfectly organized aquatic
plants, which consist solely of parenchyma, and in which this
has been demonstrated by various experiments. Unger thinks
rather that the foreign substances which are taken in pass
through the cellular partitions than that they mix with the
cellular sap; on the other hand, however, my own experi-
ments made on Lemna with salts of iron, as also on plants of
balsam and maize with prussiate of potash, show that the dis-
solved substance imbibed mingles with the cellular sap. But
if we act with reagents on such cells, the coloured substances
proceeding from the action are almost all precipitated upon
the partitions of the cells and on the molecules of the cellular
sap.

These experiments on the reception of dissolved foreign
matters through the cellular tissue were performed by Unger
chiefly in order to see whether a secretion of the imbibed sub-
stances again took place through the root. Various experi-
ments decidedly proved that the Lemna plants secreted nei-
ther the metallic salt nor the sulphuret of ammonia which
they had taken up, and I can state the same thing of the im-
bibed sulphate of iron and the prussiate of potash. Plants
of Lemna trisulca which were charged with one of these sub-
stances, and plants which had taken up the other, were placed
in a glass with clean water : they continued to grow for some
days, but exhibited no reaction in the water.

It is well known that the experiments of Macaire and Dau-
beny* went to prove such a secretion of the foreign substances
imbibed by means of the root, yet in all their experiments we
are left in uncertainty as to whether the roots were uninjured;
the contrary must even be supposed.

In all these experiments, especially when acrid substances
such as vitriol are given to the plant to imbibe, they suffer

[• A notice of Prof. Daubeny's experiments will be found in Lond. and
Edinb. Phil. Mag., vol. iv., p. 52.— Edit.]

536 Report of the Progress of Vegetable Physiology in 18S6.

very much ; if in the earth, the roots generally first die off',
and then sometimes little air-roots become developed on the
stem. This pha?nomenon seems to be very common when the
roots are in a suffering state, or if they cannot properly develop
themselves: thus Jablonski(/.c. p. 21 1 ) saw the stem of a cabbage
plant which grew in a very imperfect state in purified flowers
of sulphur, send forth several similar air-roots ; and I have
noticed it in balsams and in maize, &c. when the roots had
been destroyed in the earth by insects.

Dutrochet* has again published several observations on the
respiration of plants, which are of very high interest ; it is,
however, not every physiologist that might be inclined to agree
with the conclusions which Dutrochet has deduced from his
experiments. We will first give a general notice of the ob-
servations from which Dutrochet set out ; for he is of opinion
that the glands of the epidermis, as Amici is said to have de-
monstrated, tend to close their stomata as soon as they are
brought into contact with water. However, I have not been
able to confirm this alleged observation, and hence some
doubts may be had respecting the conclusions founded on it.
Dutrochet had previously published an observation to show
that the air in the air-receptacles of Nymphcea lutea were
richer in oxygen the nearer they were to the leaves ; whence
might be inferred that the oxygen was impelled from the
leaves through all the respiratory organs. On the other hand,
I will mention an observation which contradicts this ; for if
on a hot day we place a hardy specimen of Calla cethiopica
partly under water, and cut some of the petioles of the leaf off
just above the surface, we are able to observe that from the
influence of the solar light, a great quantity of air continually
flows from the divided air-receptacles ; but this air appears
also to be exceedingly abundant in oxygen, for ignited char-
coal shines much the brighter in it.

Dutrochet placed a severed leaf of a NympJuza under water
and observed how it disengaged oxygen, by the action of solar
light, only from the divided apertures of the air-ducts of the
petiole; he remarked the same circumstance in severed leaves
of Hydrocharis Morsus rance^ Potamogeton sericeum and My-
riophyllum spicatum. This latter plant lives entirely under
water, and possesses no stomata. But if we allow the leaves
of Nymphcea and Hydrocharis to float as in their natural state
on the surface of the water, the expiration of oxygen ceases
at the sected air-ducts of the stem. Does this disengagement
of gas cease if the ends of the divided leaf-stalk are bent up-
wards? If on the contrary severed leaves ot'Nym])hcea were

• Rechervhes sur la Respiration dcs Vegetaux. — Institut, 1836, p. 358.

Mr. Sylvester on the Optical Theory of Crystals, 537

exposed to the influence of the sun under water, the disengage-
ment of the oxygen from the divided air-ducts soon ceased ; it
began however anew if the leaves were again placed in their
natural position.

Dutrochet finally infers from his various experiments that
plants at night absorb the oxygen from the air, and that this
is only an auxiliary respiration, while the true process of re-
spiration of vegetables consists in the disengagement and dif-
fusion of the oxygen in the interior of the plant caused by the
solar light.

Morren*, who made several experiments in the botanical
garden at Louvaine on the respiration of plants, observed on
the 18th of May, during the great solar eclipse, that the re-
spiration of the green parts of plants, that is the expiration of
oxygen, entirely ceased at that time. We can observe some-
thing very similar to this on very warm summer days, when
for instance the respiration of oxygen is very considerable
from the action of solar light, and the sun all at once disap-
pears under dark clouds ; I have noticed several times how
soon the disengagement of gas bubbles diminished, and at
last ceased more or less completely.

[To be continued.]

LXXVI. Analytical Development of FresncVs Optical Theory
of Crystals. By J.J. Sylvester, Member of St. John's
College, Cambridge.

[Continued from p. 469.]
Cor. — Hence we may reduce the discovery of the two
fronts into which a plane front is refracted on entering a
crystal to the following trigonometrical problem,
p

Let a sphere be described
about any point in the line in
which the air front intersects
the plane of incedence. Let
the great 0e P I denote the
latter plane, I F the former,
O A, O C also great circles,
the planes of single velocity.
Suppose I G H to be one of
the refracted fronts inter-
secting O A, O C in G and H, then

(a* + cg) - (a*-&') cos(G + H) _ sin ( P I F)*

2 (vel. in air)* = (sinPIGH)2'

* Vlnstitut 18S6, p. 416.

Third Series. Vol. 11. No. 70. Dec. 1837. 3Z

538 Mr. Sylvester's Analytical Development

The double sign will give rise to two positions of the refracted
front 1 G H.

The propositions which follow are perhaps more curious
than immediately useful.

Proposition 10.

To determine the portion of a line of vibration in terms of the
two velocities of its corresponding front.

We have here to determine the quantities -^ — -' (of Prop. 1)

in terms of vn vll9 or on putting xf + yf + zf — 1, xlyl zt

are to be found in terms of vn vu

I m n

By Prop. (3.) *,: y,:z :: j^—^ : -^—^ : -pr^

and by Prop. (5.) I2 : m* : w2: : b2 - c2 . a2

c^__a2# 69 _ ^9 d ^_^s

^2 «2

7/9 ^2

a? — v

2 7,2 7, 2 ^»2 r

Let a, /3, y be the < es made by the given line of vibration
with the elastic axes, then

= (b2 - <?) (a2 - v2) (b2 - v2) (c2 - v2)
divided by

f (b2 - c2) (a2 - v2) {b2 - V,*) (c2 - v2)

+ (c2 - a2) {b2 - v2) (c2 - v2) (a2 - t;,2)
+ (a2 - 62) (c2 - v 2) (a2 - *>,*) {b2 - v2)

and therefore
__ (/32 _ c*) (g» - g|«) (ff - P|t) (c« - ^)
~~ K* ~ V) («" - ^) (b2-c*)(c*-a*)
(where it is to be observed that the reduction of the denomi-
nator is simply the effect of a vast heap of terms disappearing
under the influence of contact with the magic circuit a* — b2,

of Fresners Optical Theory of Crystals. 539

IP __ c*9 & _ a«9 a simpier instance of which was seen in pro-
position 5.)

In fact the coefficient of u4 . v2

= (b2 - c2) + (c2 - a2) + (a2 - b2)
= 0
that of v2 . v2 = (c2 + 62) . (c2 - 62)

+ (a2 + c2) . («2 - c2)

+ (62 + «2) . (b2 - a2)

= (C4 __ £4) + (a4 _ C4) + (£4 _ ^4)

= 0.
The term in which neither vt nor vn enters

= a2 b2 c2 {(b2 - c2) + (c2 - a2) + (a2 — 62)}

= 0.

The coefficient of

- v* = «2 . {¥ - £4) + b2. (c4 - a4) + c2 . (a4 - £4)
and that of

vf = tfc2. (c2 - £2) + c2a2.(a2 - c2) + a2£2. (£2 - a2)

each of which = (a9 - 62) . (b* - c2) . (c2 - a2)

Hence,

^cos a; - ^ _ ^2 . ^ __ ^ (fl2 _ ^ ,
in like manner (cos/3)2 = &c.

and (cos y)2 = — | ^ . Va &w~2 !r-

v ' v/5 — p/ (c2 — 62) ( c2 — a2)

Proposition 11.

cy sn being the < es between any line of vibration and the optic
axes, required the velocity due to that line in terms o(eteir
By analytical geometry,

cos s/ = cos x . cos $j + cos y . cos <k

cos ey; = cos « . cos 4>; — cos y . cos 4/i

.\ cos et . cos 6;/ = (cos a)2 (cos $;)2 — (cos y)9 (cos \^)2

v g - &* fa2 - i>, 2 . c2 - u,2 — c2 - t?,,2 . a2 - g

»,8-

I

(a2-

C)"

»,2-

- J2

(«2

-**)(<

0„a-

•o2)

•/-

(«*-

c2)2

=

6s-
a2-

}

3Z2

54-0 Mr. Sylvester's Analytical Development

Hence v2 = b2 — a1 — c* . cos st cos eIP

and in like manner, for the cotyugate line of vibration.

vt2 = b2 — (a2 — c2) cos ii| . cos e,/.

Proposition 12.
To find ey e/; in terms of *, »,,
(cos e,)* + (cos ej3

= 2 (cos a)2 . (cos $,)2 + (2 cos y)2 . (cos \J/y)2

but by Prop. (9)

v? = a2 (sin ^~y + c2 (cos ^L^)'

ft* = «? (sin -^yr) t c* (cos ^^T/

.-. (cos 6/)3 + (cos g« = ^.^ „-,,;. rin<//

multiplied by

2 {0W<((coS "+',)2(Sin^)2 + (coS^)2(-"7" )') }

(a2-C2)5

62 - vf

(a2 — c) sin it . sin

and we have seen that

b% - v?
cose, cos £// = -r=- -^

^{(sin.^ + fsini,,)*}

//A8 — **\ sin/, 4- sin i.,

\ COS 5, + COS £// = A / ( -a L \ . ,.,.,_.

' u V \«2 — c J - v sin i . sin »/y

/(ft2 — v?) sin i — sin <,,

cos i j - cos su = a / ^ ^ . . . . JL

V a2 - c* ^/sjn ; . si„ r

•(cos g/)=A/|^4. *A
V l «^ — C* sin »„ J

sin *,

V L«- — c

sin ij J*

o/Tresnel's Optical Theory of Crystals. 541

and in like manner

vt v„ for the sake of neatness are left unexpressed in terms of i{ in.
This is the simplest form by which the position of the lines
of vibration can be denoted.

Corollary.

From the last proposition it appears that
cos e, sin i

Hence we may construct geo-
metrically for the two planes of
polarization.

Let I K be the projections of
the two optic axes on a sphere, E
the projection of the normal to the
front, P the projection of one line
of vibration ; then

cosPK sin K E
cos PI sin I K

Draw F E G the 0e of which
P is the pole, meeting P K, P I
produced in G and F.

Then cos P K = sin K G, and cos P I = sin I F,
sin K G _ sinKE
sin F I sin I E

sin K G sin I F

sin K E " sin I E
sin K E G = sin I E F

•\ K E G = I E F or 180 - I E F. But P E F = P E G

.-. E P bisects either the <e I E K or the supplement to it.

These two portions of E P give the two planes of polariza-
tion. The construction is the same as that given in Mr. Airy's
tracts, and originally proposed, I believe, by Mr. Maccullagh.
[To be continued.]

[ 542 ]

LXXVII. Letter to Richard Taylor, Esq., one of the Editors
of the Loud, and Edinb. Philosophical Magazine, occasioned
by M. Melloni's paper on the Polarization of Heat in the
Annates cte Chimiejfor May 1837. By James D. Forbes,
Esq., Prof, of Nat. Phil, in the University of Edinburgh.
My dear Sir,
^VTOU may recollect last year at Bristol your having men-
-*- tioned to me your intention of translating a paper of M.
Melloni's in which my experiments on polarized heat were
referred to, and having wished to know whether I chose that
any remarks from me should accompany it in the " Scientific
Memoirs* ;" I replied that though I conceived that M. Melloni
had not dealt quite fairly by me or my experiments, yet such
was my abhorrence of scientific controversy that nothing short
of necessity should ever cause me to enter into it. I still re-
tain the same sentiments ; I still think that the opinion of
those whose opinion is alone worth having on such abstract
and unfamiliar points, will be decided by an examination of
the original memoirs in which the experiments are contained ;
to which memoirs I have given as extensive a circulation as I
conveniently could. In their hands I very willingly leave my
claim to the establishment of the chief facts of the polarization
of heat as far as yet known; and it happens, fortunately for
me, that the hostility with which my results were at first re-
ceived by those who have since taken the trouble to examine
and confirm them, prevents any, even the slightest, question
respecting priority in any part of the inquiry.

I have, however, more than once taken the liberty of using
your journal as a vehicle for combating any definite objection
urged to the accuracy of my experiments. This is all that I
mean to do in the present letter.

In the Annates de Chimie for May 1837 (but which has
only very recently appeared) M. Melloni states the results at
which he has arrived by the use of my methods of polarizing
heat, which he seems to have applied with great skill and with
his usual attention to minute accuracy. Whilst he amply con-
firms my results as to phenomena generally, he finds a marked
difference in the quantitative measures made on the amount of
heat from different sources polarized by a given pile of mica.
He endeavours to explain the difference in our results by
pointing out a source of error in mine. That this supposed
source of error has no recognisable existence, but is one of
those infinitesimal objections with which my experiments have
been from the first assailed, I shall now endeavour to show.
M. Melloni supposes that the secondary heat radiated from
* Scientific Memoirs, vol. i. p. 325.

Prof. Forbes on the Polarization of Heat. 54S

the mica plates to the thermal pile affects my results ; and
that as more dark heat than bright heat is absorbed by mica,
a greater share of the total effect is produced by this cause in
the first case than in the second. Since this secondary effect
is unchanged when the mica plates are perpendicular and
parallel, there appears to be less heat polarized in the first case
than in the second. In support of this opinion M. Melloni
quotes one of my earliest and rudest experiments, in which the
effect of absorbed beat was abundantly obvious, and which
could form no certain basis of quantitative deductions.

M. Melloni does not appear to have observed that in my
later quantitative experiments, (which he likewise quotes,) the
supposed cause of error was eliminated by observing the
dynamical effect, or the extreme arc of impulsion of the nee-
dle (a method which I borrowed from M. Melloni), and that
(the screen which was removed in order to let the heat act upon
the pile being between the source of heat and the mica plates,)
the mica plates were only absorbing heat during the few
seconds that the arc of impulsion was being observed. I have
adopted M. Melloni's mode of ascertaining the inefficiency
of the absorbed heat, (which is the same as I suggested at the
very commencement of my experiments, for the satisfaction of
those who on the very same grounds denied the polarization
of heat altogether,) and I find the effect of absorption to be
utterly inappreciable, whether for dark or bright heat.

It is clear that some other mode must be adopted to account
for the discrepancy of our results. From M. Melloni's known
accuracy and address in the use of the thermo-multiplier I
can hardly doubt the correctness of the results he has obtained.
I am also tolerably confident as to my own. Perhaps the
difference may lie in his having used more plates, and at greater
inclinations, to produce polarization ; which of course will
always tend to bring to uniformity of state rays of heat, how-
ever differently susceptible of polarization by a given plate at
a given angle, which is all the distinction I ever meant to draw
when I used for brevity the phrase " polarizable nature" of any
kind of heat.

Though I cannot help saying that it seems to me that those
who have attended to the memoirs hitherto published on this
subject will find almost nothing new either in methods or re-
sults in M. Melloni's very long memoir now alluded to, still
I feel very grateful to him for having, by delicate and judicious
arrangements of the apparatus, confirmed the resultsalready ob-
tained, on a scale which may adapt them for class experiments,
and which can leave no doubt respecting them, even on the
minds of those least accustomed to weigh physical evidence.

544- Prof. Schoenbein on the peculiar Voltaic

As I refer to my own papers as the only answer which I
mean to give to the other parts of M. Melloni's memoir, I
will add that \hefast appeared in the Edinb. Trans., vol. xiii.,
and Lond. and Edinb. Phil. Mag., vol. vi. ; the second (con-
taining the more accurate measures) in the Edinb. Trans., same
volume, but it has not been reprinted.

I am, my dear Sir, yours very faithfully,
Edinburgh, 15th Nov. 1837- James D. Forbes.

LXXVIII. On the peculiar Chemical Inactivity of Bismuth, with
reference to the researches of Dr. Andrews ; and on the action
qfSeawater on Iron, Sfc. By Professor Schcenbein.*

fT,HE short notice contained in the last number of the Bi-
-*- blioth. Univers. respecting Dr. Andrews's researches on
the action of nitric acid upon bismuth, f has induced me to make
some experiments on the same subject, and I now take the
liberty to give you a short account of the results obtained
from them. It certainly cannot be denied that there exists
some analogy between the peculiar condition of iron and that
of bismuth, but my impression at present is, that the cases are
similar, but not identical. This opinion is founded upon the
following facts : The chemical action of iron upon nitric acid,
as is now well known, can be entirely stopped by a variety of
ways, whilst according to my experiments it is impossible to
obtain such a result with bismuth. I voltaically associated this
metal with all the substances known to be capable of rendering
iron completely inactive, but by so doing I could never succeed
so far as to prevent bismuth from being chemically acted upon
by nitric acid. It is true, by putting in contact the metallic
body in question with platinum, the chemical action of nitric
acid, sp. gr. 1 '4-, may be reduced to such a low degree of in-
tensity that no visible disengagement of binoxide of nitrogen
takes place, and the piece of bismuth (immersed in nitric acid)
assumes a bright appearance.

But the oxidable metal being in this state is nevertheless
uninterruptedly attacked by the acid fluid, as may be easily
shown by having recourse to the galvanometer. There are
besides some other facts, which put the continuance of che-
mical action in the circumstances mentioned beyond any doubt.
L think I have first ascertained the remarkable fact, that iron
can be rendered thoroughly inactive, not only towards the
oxygen of nitric acid (of any degree of dilution), but also to

• Extracted from a Letter to Dr. Faraday, and communicated \>y him.
t See the present Number, p. 554. — Edit.

Inactivity of Bismuth and Iron. 545

the oxygen disengaged (by the action of a voltaic current) out of
aqueous solutions of any oxidized body or any oxyelectrolyte.
You know that such a state of iron is called forth by making*
this metal act the part of the positive electrode of a pile and
closing the circuit in a certain manner. Now if bismuth be
placed in these very same circumstances, it does not seem to
undergo any change whatever, for it is violently acted upon by
nitric acid (of sp. gr. 1-4) and unites with the oxygen resulting
from the electro-chemical decomposition of water or any other
oxyelectrolyte. It is particularly the last-mentioned difference
of bearing between the two metals which makes me suspect that
the peculiar condition of iron is not produced by the same
cause which occasions the inactivity of bismuth, that is to say,
that the latter effect is not brought about by a current passing
in a certain direction through bismuth. There is another fact
which seems to speak in favour of this opinion : according to
my experiments, peroxide of lead proves to be the most power-
ful of all substances which are capable of turning common iron
into its peculiar state. Peroxide of lead, in whatever manner I
tried to combine it with bismuth, did not appear to have any
action upon the metal, for this substance was dissolved by ni-
tric acid just in the same way as it was when put into the said
fluid without any voltaic association. Now it is to be asked,
in what manner does platinum weaken the chemical action of
nitric acid upon bismuth? Are we to believe that in the case
in question the former acts in a quite peculiar way, that it puts
into play an agency of a nature as yet unknown and entirely
different from current electricity ? I am certainly not much
inclined to draw any such inference from the fact alluded to,
but at the same time 1 must confess, that for the present, at
least, I am not able at all to account for the anomaly spoken
of. Before passing from the subject of the peculiar condition of
bismuth to another one, allow me to mention to you some more
phenomena which bear upon the same matter, and which have,
perhaps, not yet been observed by Mr. Andrews. After (by
the agency of platinum) the violent action of nitric acid (sp. gr.
1*4) upon bismuth has been changed into a slow one, and both
metals brought out of contact, bismuth loses its metallic lustre
and assumes a blackish appearance ; after a short time, how-
ever, the metal turns bright again by itself, and remains so
until it is touched a second time by platinum. As long as the
contact between both metals is maintained, certainly there
is no change of the surface of bismuth to be observed, but no
sooner have they ceased to touch each other than the bismuth
begins to blacken again ; it reassumes, however, after some
lapse of time, its former lustre. This change of surface can
Third Series. Vol. 1 1. No. 70. Dec. 1837." 4 A

546 Prof. Schoenbein on the Chemical Inactivity of Bismuth, fyc.

be effected as often as you like. I have ascertained that bis-
muth covered with the said blackish coating is more energe-
tically acted upon by nitric acid than it is when its surface ap-
pears to be bright. Now as platinum, by means of its contact
with bismuth, causes a very considerable diminution of the
energy of chemical action of the acid upon the latter metal,
and makes the black film always and instantaneously disap-
pear from it, the reproduction of this coating under the cir-
cumstances before mentioned is a fact very strange indeed, and
altogether anomalous. Another fact also worthy of being
stated is, that the black film can be produced either by moving
the bright bismuth about within the acid or by causing the acid
to be moved about the metal. I do not yet know what the
black substance consists of, but whatever it may be, its produc-
tion in the last-mentioned way is no doubt due to the removal
of some stratum surrounding the bright metal and protecting
the bismuth against the violent action of nitric acid. This
supposed stratum consists perhaps of a solution of nitrate of
bismuth mixed with some nitrous acid.

If bismuth being in its peculiar state or covered with theblack-
ish film be tightly [strictly ? J touched with a platinum wire within
nitric acid of sp. gr. 1*4, a gaseous substance will be disengaged
at the wire all the while contact is maintained between the
metals. Having not yet made the experiment on a scale large
enough to allow the collection of the gas, I do not know its
nature. I have stated however the fact to you, because the
development of a gaseous body under the circumstances al-
luded to must appear very odd, if we consider, that no gas
whatsoever is disengaged at the negative electrode when nitric
acid of some strength, for instance of sp. gr. 1*4, is sub-
jected to the action of the current of a pile. Now in the case
spoken of, the platinum wire does certainly act the part of
the negative electrode. As every circumstance connected with
the peculiar condition of readily oxidable metals appears to me
to be of some importance, I will not omit to mention the fact,
that inactive iron cannot be brought into contact with inactive
bismuth without being thrown into chemical action. Iron,
however voltaically associated with platinum, is proof to the
exciting influence of the passive bismuth, and capable of de-
stroying the often-mentioned black substance Justin the same
manner as platinum. Some few words more on the peculiar
state of bismuth and I have done with this subject, with which
I am afraid I have already occupied you too long. By im-
mersing that metal for a few seconds into nitrous acid it is
turned inactive, so that it can be put into nitric acid of sp. gr.
1*4 without being sensibly attacked by the latter.

Cobalt and Nickel incapable of being rendered, inactive. 54-7

The Biblioth. Univers. also alludes to a paper read at
Liverpool by Mr. Hartley, on the Preservation of Iron against
the action of sea water. The fact stated by that gentleman is
on account of its anomaly highly interesting, and seems to
enter into that class of electro-chemical phenomena which
have been the subject of my researches these last two years.
If you recollect a statement of mine made in a paper " On a
peculiar Action of Iron," &c.,* you will be aware that the re-
sult obtained from Mr. Hartley's experiments does not quite
agree with what I have found out to be a general fact. The
statement alluded to runs as follows: In solutions containing,
besides oxy electrolytes, others of a different nature, for instance,
hydracids, haloid salts, &c, no evolution of oxygen takes
place (at the iron being the positive electrode of the pile) in
whatever manner the circuit may be closed. Now if in Mr.
Hartley's voltaic arrangement brass is to iron (in an electrical
point of view) what platinum is to the latter or any other
readily oxidable metal, according to my experiments we
should suppose that iron, being voltaically associated with
brass, would be chemically acted upon by sea water, that is to
say, be oxidized and chloridized. You may easily ascertain
the correctness of my statement by plunging an iron wire
which is connected with the positive pole of a pile into an
aqueous solution of chloride of sodium, closing thereby the cir-
cuit. You will observe that the iron is not turned inactive, but
corroded, and effects are produced quite consonant to the well
known electro-chemical laws. I made a couple of days ago
some experiments with sea-water itself, and I found that iron
was attacked by it when a current passed from the metal into
the fluid. As you can easily imagine, the disagreement of
Mr. Hartley's observations with mine, makes me exceedingly
desirous of becoming acquainted as soon as possible with the
particulars of that gentleman's researches. I hope the next
number of the Philosophical Magazine will satisfy my curiosity
on this point.f

Last summer, during a short stay at Stuttgard, I made in the
laboratory of Professor Degen there, and in company with this
able chemist, some experiments upon cobalt and nickel, to as-
certain whether these metallic bodies are capable of being
rendered inactive. Having but a very small quantity of these
metals at our disposal, we were obliged to limit the number
of our experiments to a very few, and to execute them on

* Lond. and Edinb. Phil. Mag., vol. x. p. 267.

t We are not aware that any further statement of Mr. Hartley's results
has yet appeared : that given in page 554 of the present Number is sub-
stantially the same with the notice cited above.— Edit.

4 A2

548 Notices respecting New Booh.

a very small scale. The results obtained from them were,
however, such as to convince us, that the peculiar condition
cannot be excited either in cobalt or in nickel ; at least not
in the same way as it is done in iron. This fact seems to in-
dicate that the peculiar voltaic state of the latter metal has
nothing to do with its magnetic properties.

Believe me ever to be yours very truly,
To Dr. Faraday, fyc. fyc. C. T. Schcenbein.

LXXIX. Notices respecting New Books,

A Synopsis of the Family of Naiades. By Isaac Lea, Member of
the American Philosophical Society. Large 8vo. with 1 coloured
plate. Philadelphia, 1836.

In most families containing a great number of species the cha-
racters are generally found to shade so much into one another, that
it is often almost impossible to draw the line of distinction. Such
is the case with this interesting family of Mollusca, of which more
than 344 species are enumerated. The author divides the family
into two genera, Margarita and Jridina. The first he then sub-
divides into Unio, Margaritana, Dipsas, Anodonta, and Pleiodonr
according to the existence and situation of the teeth. These sub-
genera are again divided into Symphynote and Non-Symphynote.
Great attention has been paid to the Synonymy, which is enormous,
and attended with many difficulties; and even this alone would ren-
der the work of great importance to every Conchologist. The nu-
merous notes contribute not a little to its value, and evince the great
labour and sound judgement of the author.

Bibliographical Bulletin.
Einfluss des Bodens auf die Vertheil d. Gexv. (The influence of the

soil on the diffusion of Vegetables demonstrated in the vegetation

of the north-easterlv part of the Tyrol). By Prof. F. Unger, Vienna,

1836. Svo.

Our readers will already have seen this work noticed in Meyen's Report
on Vegetable Physiology, p. 445, &c, where an extract from it is given :
we, however, think it well worth while to direct attention to it, as it
contains results which will probably be of vast importance in the physiology
and geography of plants. The work is divided into three parts; geological,
meteorological, and botanical. The author first considers the chorography,
the situation, geological system, springs, nnd lakes in the neighbourhood of
Kitzbiihel. Then follows the petrography and geography of a great part of
the Tyrol, which on account of the minute details, is of great value to the
mineralogist. With the meteorological observations are given two tables on
the condition of the barometer and one on the temperature. The botani-
cal part is rich in comparisons of the vegetation with the localities, moun-
tain and valley, and especially with the geological formations and condi-
tions of temperature. Various new observations and experiments have been
made on the structure of plants, their nutritive organs, and the substances
which they take up. To these are added various maps, plates, and a cata-
logue of all the plants, cryptogamiaand phanerogamia, occurring there (1773

Notices respecting New Books. 5i9

species are enumerated, among which 818 cryptogamia). The work evinces
great care and labour in the author.

Ahbildungen neuer od. unvollstandig bekannter Amphibien (Figures
of new or imperfectly known Amphibia), sketched from living
specimens, and accompanied with text by Dr. H.Schlegel, Cura-
tor of the Museum of Leyden. Parti. Dusseldorf, 1837.
In no branch of natural history are figures more necessary than in Am-
phibiology, and those of the present work from their excellence, being drawn
and coloured after nature, merit approbation. Most of the numerous and
beautiful drawings, executed in India by order of the Dutch government, by
Reinwardt, Kuhl, van Hasselt, Boie, and Maclot, are to be given in this
work. Great attention will be paid to the anatomical details and natural
history of the serpents, a department hitherto rather neglected. The form
of the work is that of Temminck's Planches coloriees d'Oiseaux, which
it surpasses as to drawing and colouring, and it may be considered as com-
pleting the works of Lacep&de, Russel, Neuwied, Bell, Wiegmann, and
others. Each part contains ten plates, with text, at a moderate price.
Wiegmann's Archiv, Part 4. Berlin. 1837.

Contents.— A brief view of the history of the development of vegetable
organization in the Phanerogamiaj by Dr. M. J. Schleiden. (A transla-
tion of this interesting paper will shortly appear in this Journal).— On the
generation of Pteroptus Vespertilionis ; by Chr. L. Nitzsch. — A new genus
of water-serpents described by J. Tschudi. — Filaria? in the brain of the
foetus of a Lizard; by Prof. Rathke. — Contributions to the knowledge of
the Trilobitesy with especial regard to their definite number of Members ;
by A. Quenstedt. — On the genus Procyon\ by Prof. Wiegmann. — Fossil
quadrumana. — Ehrenberg's new discoveries respecting the Bacillaricc (See
p. 448 of our present volume). — Notice on the bite of the Moco (Cavia ru-
pestris, Neuw., Kerodon, F. Cuvier); by Prof. Wiegmann.— Report en the
progress of Zoology during 1836; by Prof. Wiegmann.
Poggendorff's Annalen, 1837. Nos. 6 and 7.

Contents.— On an apparatus for performing Volta's fundamental experi-
ments ; by T. Fechner. — On the expansion of dry air between 0° and 100°;
by F. Rudberg. — On the oxidation of metals in atmospheric air; by A. v.
BonsdorfK — On the calculation of the forms belonging to the tessular system
of crystals; by Fr. v. Kobell. — On the crystalline form of Phenakite; byjE.
Beyrich. — Description of a Mica-copper ; by F. Benecke. — Analysis of the
copper-mica ; by F. Borchers.— Proportional combination of the oxide of
silver and oxide of lead ; by F. Wohler. — On the formation of the oil of
bitter almonds ; by F. Wohler and J. Liebig.— Proposal for the adoption
of a new medicine instead of distilled laurel and bitter almonds water; by
F. Wohler and J. Liebig. — On Amy 'gdalic acid and some of its salts ; by F. L.
Winkler. — Composition and constitution ofAmygdalic acid; by J. Liebig. —
Method of preparing the bicarbonate of Potash ; by Wohler. — On the de-
composition of some of the aethereal oils extracted from various Cinna-
mons; by G. J. Mulder.— On Marcet's Xanthicoxide ; by Liebig and
Wohler. — Additional notices respecting Arsenic and its combinations; by
J. F. Simon. — Detection of quicksilver in the saliva voided after the use of
the mercurial salivation ; by L. Gmelin. — Solubility of mercurial vapour
in water ; by A. Wiggers. — On a new air-pump ; by N. Lowenthal. — In-
structions and tables for rendering easy the calculation of the specific gra-
vity of gases from observed facts; by Poggendorff.— Experiments on the
specific heat of gases and of the air at different pressures; by G. Suermann.
— On the specific gravity of sea-water collected at different periods at the
same places of the ocean; by J. Childer. — On the Knee press -, by T.

550 Notices respecting New Books.

Fechner. — Theory of the colours of thin plates; by Prof. Airy. — Two letters
to A. v. Humboldt ; by von Kreil : Observations on the magnetic devia-
tion, inclination, and horizontal intensity at Milan in the years 1836 and
18.37, with the description of a new Inclinatorium. — Meteorological ob-
servations made in 1836 at Baunsberg in East Prussia; by J. Feldt. —
Results of the meteorological observations made at Karlsruhe in 1834 and
1835; by D. Otto, Eisenlohr. — On the relative masses of existing siliceous
infusoria, and on a new infusorial conglomerate in the state of polirschiefer,
found at Jastraba in Hungary; by Ehrenberg.

Neue Notizen von Froriep, vol. ii.

Contents. — No. 18. No ciliary organs in the Spermatazoa of the Sala-
mander; by C. Th. Siebold.— No. 19. On the forces which regulate the
internal constitution of bodies ; by O. F. Mossotti, (For this remarkable pa-
per see Scientific Memoirs, vol. i. p. 448. L. & E. Phil. Mag., vol. x. p. 320.)
— On the phosphorescence of organic bodies. — No. 20. On the animalcules
in the sap of plants. — No. 22. Contributions to the physiology of Fishes.
— On the elevation of the ground in the neighbourhood of Naples, and the
origin of the island Julia in the neighbourhood of Sicily.
Flora oder allgem. Botanische Zeitung. No. 7, &c. 1837.

Contents. — Remarks on some Graminece; by Prof. Tausch. — Remarks
on Erysimum lanceolatum R. Brown ; E. ochroleucum De Candolle, rhceti-
cum De Can. and pumilum, Gaud.; by Guthnick. — On two North American
species of the genus Valerianella ; by R. J. Schuttleworth. — On Rhododen-
dron-y by Zuccarini. — On Rhododendron; by L. Reichenbach. — Observa-
tions on some Saliceoe. — Proceedings of the Royal Botanical Society of Re-
gensburg. (This work contains many other papers which we have not con-
sidered to be of particular interest, as they relate entirely to Germany,
such as the Floras of certain districts.)
Neues Jahr buck Jlir Miner alogie, &c; by Leonhard and Bronn,

1837.

Contents. — No. 2. Excursion into the department of Isere ; by Lortet. —
On the age and organic remains of the tertiary formation of the Mainz
basin; by Bronn. — No. 3. Geognostical and physical observations on the
volcanosof the high land of Quito; by A. v. Humboldt. — On the sub-fossil
remains of Puzzuoli near Naples, and on the island Ischia ; by Prof. A. Phil-
lipi.— Description of a new species of Nerina and a new fossil species of
Pecten ; by the same. — On the organic forms in the agate near Schlott-
witz ; by B. Cotta. — Notice on the genus Aptychus ; by Voltz.
Archiv der Pharmacie; by R. Brandes, vol. ix. Part I. 1837.

Contents. — A voltaic battery of easy construction, and some remarks on
Faraday's views on Electricity; by Dr. Geiseler. — Notice on Fusel oil; by
C. Stickel. —On the natural springs of carbonic gas near Meinberg, with
some general remarks on mineral waters ; by R. and W. Brandes. — Poison-
ing by prussic acid cured with carbonate of ammonia; by Dr. Geoghegan.
Zeitschriftfur Physik, &c. ; by Baumgartner and Holger. Parts II.

and HI. 1837.

Contents. — On the alkaline action of the mineral water of Pullna, of
some calcareous fossils, bicarbonate of lime, and more especially on the
mineral water of Prague; by Ad. Pleischl. — On the testing and division of
areometer scales ; by Aug. Neumann. — General view of the meteorological
relations in 1836. — Observations on two invariable reversion-pendulums;
by J. von Littrow. — On Legrand's observations on the oscillations which
the scales of mercurial thermometers undergo; by W. Gintl.

Studigeologi sulla Toscana ; by Savi.

British Association for the Advancement of Science. 551

Annates de Chimie et de Physique. June 1837.

Contents. — Action of sulphuric acid on oils; by E. Fremy. — On Oleic
acid and Elaidic acid ; by A. Laurent.— Note on the cause of the red co-
louring of the salt-water basins; by Payen. (The author attributes this
circumstance to the presence of a small crustacean known in England by
the name of brine-worm, Artemia satina? of Leach, but in a paper of Dunal
it is affirmed to be caused by the presence of some Alga?). — On the gases
contained in the blood, oxygen, nitrogen, and carbonic acid ; by G. Mag-
nus. (From this memoir it appears that not only does the venous blood
contain carbonic acid, oxygen, and nitrogen, but also the arterial blood,
and that relatively to carbonic acid the arterial blood contains much more
oxygen than the venous. This is a very interesting paper and will probably
find a place in one of our future numbers). — Action of sulphuric acid on
the hydruret of benzoyl; by A. Laurent. — Researches on the coercitive force
and the polarity of magnets without cohesion; by Dr. Haldat.

LXXX. Proceedings of Learned Societies.

BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE :
MEETING AT LIVERPOOL.

Section of Zoology and Botany, September 11. — Mr. Gray offered
some remarks on the supposed production of insects by the ex-
periments of Mr. Crosse, and referred to two experiments made
by Mr. Children in a munner perfectly identical with those of the
former. The solution of silica was obtained from Mr. Garden, of
Oxford Street, and in one experiment it was sealed up, whilst in
the other it was exposed to the air, but in neither case was there
any appearance of insects. The insects had been very indefinitely de-
scribed by Mr. Crosse, some as having six, and others eight legs. It
was no proof that they could not have been produced from the water
used in the experiment because it was boiled, as that would not be
sufficient to destroy the eggs of the insects deposited therein. — The
Rev. Mr. Hope remarked one peculiarity, that no one had given the in-
sects a specific name, and that they merely appeared to belong to the
commonest species of Acari. — The Chairman (Mr. W. S. Macleay)
mentioned the circumstance, that the seeds and germs of animals
and vegetables are earlier and more quickly developed in a current of
electricity, and that in all probability, these favourable circumstances
operated upon the eggs of the insects produced in question. It was
well known that seeds would retain their vitality for an indefinite
period of time, and there was no reason why any limit should be put
to the vitality of the eggs of animals. — Mr. Gray stated that prussic
acid had lately been used for the purpose of destroying insects at the
British Museum, particularly those infesting a mummy. Some of the
larva? of the common Musca having been put into the acid, remained
uninjured after two or three days exposure. — Professor Grahamj( Univ.
Edinb.) remarked, that other plants and animals might be keptfo^an
indefinite length of time, when the powers of life were either retained
or suspended. He also alluded to some curious experiments recently
made at Edinburgh, although first by Sir Astley Cooper in London,
with respect to the circulation of blood through the brains of particular
animals. If the circulation be suspended by pressure for half a mi-
nute, the animal becomes torpid, but after giving a few convulsive

552 British Association for the Advancement of Science.

sobs recovers ; whilst if it is suspended for a minute the animal irre-
coverably dies. — The Chairman observed that he had often dried to
powder the eggs of various insects, which having been put into water
were hatched.

Mr. Golding Bird referred to the observations of Mr. Gray, with
respect to the production of insects, as stated by Mr. Crosse in his
experiments, which he had repeated on a large scale, but without
any result, although he had continued them for some weeks, varying
them in every possible form. He also explained that such could
not have been produced from the silica, as this was precipitated from
the mixture of the alkaline solution of silica and muriatic acid, the
fluid passing through the filter being nothing but very dilute mu-
riatic acid.

Sept. 12. — The President observed that he was about to read
a letter upon a subject that had excited some interest in the scien-
tific world, on account of the difference between two eminent
naturalists, — Mr. Thompson and Professor Rathke, of Berlin. He
remarked, that at first sight it appeared strange, that animals ap-
parently so high in the scale of organization as the crabs and lobsters
should undergo the same changes in the course of their develop-
ment, as the class Insecta. Mr. Thompson had observed, that the
young of the barnacle shell were deposited by the parent in a free state,
and that they afterwards became fixed 5 and the same fact had been
pointed out to him by that zealous naturalist Mr. Darwin. It was
therefore not extraordinary Mr. Thompson should take the view he
did of the development of Crustacea. The letter he had on this sub-
jectwasfrom Capt.DuCane, of Southampton, who, from his contiguity
to the sea, had been led to investigate this subject. He had obtained
the ova of what he supposed to be the common prawn : after keep-
ing them in water a little time, they produced a number of minute dia-
phanous animals, altogether different from the full-grown prawn.
These ova were obtained from a ditch open to the influx of the sea,
but the water was only slightly brackish. Captain Ducane therefore
proposed to call this animal the " Ditch Prawn." The letter was ac-
companied by a drawing, exhibiting the various changes which the
Captain had observed to take place in these animals during the first
three days after their leaving the ova, none of his specimens living a
longer period.

The President observed, that the subject of the development of
Crustacea was a most interesting subject. He questioned whether
many of the received species of that class were anything more than
one animal in its several stages of development.

Dr.Richardson inquired if it might not be possible for Capt. Du Cane
to have mistaken some parasitic animals for the young of the prawn.
The Rev. F. W. Hope was inclined to think the animal alluded to be-
longed to the shrimp, and not to the prawn family. On the Norfolk
and Suffolk coast, the ditch shrimp was common. He believed crus-
taceous animals themselves were frequently parasitic. — The President
replied, that the ova obtained by Capt. Du Cane were too abundant
to be the produce of a parasitic animal, and the results too constant
to lead to such a supposition.

Mr. Gardner and Mr. Nevin on Vegetable Physiology. 553

Mr. Bowman read a paper from Mr. Gardner, * On the internal
structure of the wood of Palms.' The attention of Mr. Gardner, who
is residing in Brazil, was directed to this subject by the remarks made
by Professor Lindley, in his 'Introduction to Botany.' In order to
test the truth of the theory of Mohl, he made several experiments on
the palms in his district. He made a vertical section of a palm, four
inches in circumference, and, by doing this, he could trace very plain-
ly woody fibres proceeding from the base of the leaves to the centre
of the stem, at an angle of 18 degrees j they then turned downwards
and outwards to within a few lines of the external cortical part of the
stem, running parallel with its axis. The distance between these two
points was about two feet and a half. The fibres were traced quite
distinctly up into the centre of the leaf. In answer to the questions
proposed by Lindley in his work, the author stated : — 1. That the
wood of palms was always hard and compact outside, gradually get-
ting softer towards the centre, the fibres of the upper leaves not de-
scending to so great a depth as the lower. 2. The wood is much hard-
er at the bottom than any other part of the stem, the inhabitants of
tropical climates using only this part for economical purposes.

Professor Lindley observed, that this paper confirmed the views of
the structure both of endogens and exogens, which had been increa-
singly embraced by botanists. In the first place, the views of Mohl
on the structure of endogens were confirmed. There was, however,
a slight difference between Mr. Gardner and Professor Mohl ; the
latter having stated that the woody fibres of endogens terminated in
their cortical integument, whilst the former had traced them only
within a Yew lines of this point. In the next place, the paper confirm-
ed the theory of the formation of wood from the emanation of fibres
from the leaves. Whatever might be the difference between the ar-
rangement of the fibres of exogens and endogens, there could be no
doubt that their origin was the same. Mr. Gardner had referred, in
his paper, to the glandular disks on the woody fibre that were, at one
time, thought to characterize the order Coniferae. He would, how-
ever, draw the attention of the section to a fact that had lately been
discovered, and not hitherto published, that these glandular disks ex-
isted on all the woody fibres of plants that yielded resinous matter.
Brown first discovered them in the wood of Tasmania {Winter acece),
and Griffiths had since demonstrated them in Spherostema (Schizan~
drece).

Mr. Nevin detailed some experiments on vegetable physiology.
The experiments were performed on elms forty years of age, in Fe-
bruary, 1836.

1 . The stem of the tree was denuded, in a circle, of its cortical in-
tegument alone, leaving the alburnum beneath uninjured. On the
May following the denuded part was filled upbythe exudation of bark
and wood from the upper surface of the wound, and the tree had not
suffered in growth.

2. The bark and cambium were removed in the same manner. In
August 1837 this tree sickened, and there was no formation of wood
or bark in the wounded part. Two developments however, took place

Third Series. Vol. 1 1 . No. 70. Dec. 1837. * B

55^ British Association for the Advancement of Science.

one above the other, from below ; the former having the appearance
of roots, the latter were brunches with leaves.

3. The bark and two layers of alburnum were cut away. The tree
was at the time unhealthy ; it however put forth its leaves on that
and the ensuing spring, but shortly after died. No sap was observed
above or below the wounded part. Roots were developed from the
upper, and branches from the lower part of the section.

4. The bark and six layers of alburnum were taken off. The tree
became much less vigorous, but did not die, and otherwise presented
the same appearance as the last.

5. The bark and twelve layers of alburnum were stripped. The
consequences were again similar to the last two ; the alburnum above
and below the cut being dry, but an accidental cut that penetrated
into the heart-wood exuded sap.

6. This was a repetition of the experiment of Palisot de Beauvais,
by cutting away a circular ring of bark around a single branch. The
branch continued to grow, and roots sprouted from the under surface
of the isolated bark and branch.

7. In this the whole of the wood of the tree was cut away, except
four pillars, composed of bark and sap-wood. In this case, the sap
first appeared from above, descending by the pith, and then from the
heart-wood, the alburnum being dry. In this case the sap must have
passed up the alburnum, and horizontally through to the heart- wood.

Mr. Nevin inferred from these experiments — 1. That the life of
the tree does not depend on the liber or cambium. 2. A descent of
sap takes place before the developement of leaves. 3. That new mat-
ter arises from below j which had not previously been allowed. He
thought there were two distinct principles in the tree, — one, the as-
cending, or leaf principle ; the other, the descending or root principle.
Mr. Nevin had also performed some experiments on the conversion of
roots into branches, and came to the conclusion, that buds or branches
might be developed from any part of the root above its extreme end,
from which point it was impossible for buds to be developed.

Professor Lindley remarked that these experiments confirmed en-
tirely the theory of the structure of wood adopted by Du Petit Thouars.
He did not think that the existence of any new principle could be in-
ferred from the experiments. In the seventh experiment the hori-
zontal circulation of the sap was proved, and confirmed the accuracy
of Hall's experiment of cutting a tree nearly through on alternate
sides, when the sap still ascended.

Section of Chemistry and Mineralogy , Sept. 1 2. — Mr. Hartley read a
paper, 'On the Corroding of Iron by salt water.' The object of the
paper was to show that brass protects both bar and cast-iron in a very
perfect manner. The brass did not appear to have undergone any ac-
tion, which, as stated by the President, (Mr. Faraday,) is rather op-
posed to received notions of electro-chemical action.

Dr. Andrews next read a paper, • On some singular modifications
of the ordinary action of nitric acid on certain Metals.' Bismuth in
nitric acid of specific gravity 1*4, was rapidly acted upon, but this ac-
tion immediately ceased when the bar was touched by platinum. On

Dr. Andrews on the Chemical Inactivity of Bismuth. 555

removing the platinum from the liquor, the bismuth will sometimes
begin again to dissolve; at other times, its surface will become co-
vered with a black crust, which is soon removed by the acid -, but the
metal, though now exhibiting a beautifully-polished surface, is no
longer acted upon by the acid, or, at least, is dissolved only with ex-
treme slowness. Thus, a slip of metal, which, in its ordinary state
will require only a few seconds to complete its solution, will, when
thus slightly modified, resist for many hours the action of the same
acid.

Copper and tin present similar phenomena, but zinc, when treated
in the same way, has its oxidation and solution not arrested, but
merely retarded. Arsenic was found to present a singular anomaly
when heated in nitric acid so as to give rise to effervescence : the
contact of the platinum in the usual way did not produce any effect j
whereas, when an acidulous solution of silver is used, platinum exer-
cised its usual influence.

In the case of six metals, platinum checks the action of nitric acid,
and three of them appear to be brought into a permanently peculiar
state, opposed to chemical action. Platinum always separates any
film of oxide as its initial function ; but after its separation, it exer-
cises a polarizing action, for example, it brings the other metal into
a peculiar state, which enables it to resist chemical action.

On the conclusion of this paper, the President drew the attention
of the Section to the analogy between the facts detailed by Dr.
Andrews, and the preservation of iron by brass, as instanced in
the communication of Mr. Hartley. In both cases, according to the
known laws of electro-chemical action, effects, the very opposite of
what are observed, should present themselves. The bismuth, copper,
&c, should oxidize quickest when in contact with the platinum; and if,
as would seem demonstrated by Mr. Hartley, brass protects wrought
and cast-iron, the brass itself should be acted upon with increased
rapidity. The solution of these anomalies, he conceived to be quite
within the range of science in its present state, and he urged upon the
members of the Section the necessity of studying the phenomena in
question, as their explication would constitute a very valuable addition
the existing state of our electrical knowledge*.

Section of Geology and Geography, Sept. 1 2. — Mr. Horner exhi-
bited to the Section a drawing representing some of the Geological
phaenomena in the neighbourhood of Christiania, in Norway, and
read a letter from Mr. Lyell in explanation. This part of Europe
received some years ago an examination from M. von Buch, and the
results were at that time presented by him to the scientific world
in such a manner, as to excite much attention, and to stagger
many in their attachment to the Wernerian Theory, then very preva-
lent. Von Buch had discovered granite overlying fossiliferous strata
outstepping the bounds prescribed to it by Werner, so that his disci-
ples were obliged to invent a creation of it at a later date, to explain
the Norwegian phaenomena. Mr. Lyell has lately examined this in-
teresting locality, and has found the junction of the granite with the
* See Prof. Schcenbein's paper in the present number, p. 545.
4B2

556 British Association for the Advancement of Science.

fossiliferous rocks well determined ; also that it not only sends veins
into them, but that it actually in some degree overlaps them, the
strata rather turning up from it. The granite sometimes becomes sy-
enitic, passing into trap porphyry ; and it has altered the appearance
of the adjacent rocks, making them truly metamorphic. These fossi-
liferous rocks rest upon gneiss, and may be referred to the Silurian
system of Murchison. The granite in the same vicinity comes in con-
tact with the gneiss, which rock has frequently indications of having
been disturbed before the deposition on it of the Silurian rocks, and
it bears on its surface marks of scoring and abrasion. The posterior
formation of the granite is proved by its veins in the adjacent rocks,
and by the fragments of gneiss in the Silurian strata. The entire
phaenomena are of the highest interest, — they must have been origin-
ally submarine, as the disturbances would have been vastly greater,
had they not taken place under a pressure of perhaps some miles of
ocean in depth, and perhaps also with other strata upon them : the
gneiss, under such a pressure may have been only softened. Near
Christiania, many dykes, evidently of volcanic origin, also occur;
these are of syenite passing into greenstone, and are evidently fissures
filled with injected matter.

Section of Mechanical Science, Sept. 12. — Mr. Fairbairne then read
a report on the comparative strength and other properties of cast
iron, manufactured by the hot and cold blast respectively.

At a previous meeting of the Association, Mr. Hodgkinson read a
report on the comparative strength and other properties of iron ma-
nufactured by the hot and cold blast. — In the prosecution of inquiries
since made, it was conceived desirable to subject the metals operated
upon to more than one species of strain j to vary theirforms, and, by
a series of changes to elicit their peculiar as well as comparative pro-
perties. First, they have been drawn asunder by direct tension. Se-
condly, they have been crushed by direct compression, both in short and
long specimens, (the results of which will be given in a paper read sub-
sequently) j and, Thirdly, they have been subjected to fracture by
transverse strain, under various forms of section, and at various tem-
peratures. Ten bars of hot and cold blast iron were also loaded with
different weights from 1 121b to near the breaking point, and left for
many months to sustain the load, and to determine the length of time
necessary to effect the fracture. The bars thus loaded, are still (with
one exception) bearing the weight, having been suspended up-
wards of six months, and from what we can at present perceive, there
is every chance of a long and protracted experiment. In making the
experiment on transverse strain, a number of models of different sizes
and forms were prepared, and the irons, both hot and cold blast, were
run into the form of these models ; but as there is usually a slight de-
viation in the size of the castings from that of the model, the dimen-
sions of the bars were accurately measured at the place of fracture,
and the results reduced by calculation to what they would have been
if they had been cast the exact size of the model, assuming the strength
of rectangular beams to be as the breadth and the square of the depth,
and the ultimate deflection to be inversely as the depth, the length

Mr. Fairbairne on Hot and Cold Blast Cast Iron. 557

being constant. In comparing two irons, the greatest care was taken
to subject them as nearly as possible to the same treatment.

A series of experiments was also made to determine the strength
of hot and cold blast iron at various temperatures, from 32° (the free-
zing point) to the boiling point ; for this purpose a cast-iron trough
was employed, in which the bars to be broken were placed and covered
with snow or water (which was kept at the proper temperature by a jet
of steam) as the case required ; the weights were then gradually laid
on until fracture took place.

The strength of bars made red hot was also tried, and contrary to
expectation, they retained their tenacity and power to resist the load
to a considerable extent : the reduction of strength in a bar one inch
square, in a range of temperature from 32° to that of redness was ra-
ther more than one-sixth, the deflection being upwards of l£ inch in a
bar 2 feet 3 inches long.

RESULTS.

Carron iron, No. 2. (Scotch.)
Mean ratio of transverse strength, assuming the cold

blast iron at 1000 : 9799

Mean ratio of power to resist impact . . . 1000 : 1038*9

Whence in the transverse strength of Carron iron No. 2, using a
variety of forms of section, the strength of the cold blast is to that of
the hot blast, as 100 to 98, nearly.

Devon iron, No. 3.
Mean ratio of strength in sections of various forms (thir-
teen experiments) 1000 : 1409

Power to sustain impact 1 000 : 2742

This is an exceedingly hard iron with a singular appearance, the cen-
tre or more granulated parts of the fracture being surrounded with a
circle having the appearance of hardened steel.

Buffery, No. 1, Staffordshire iron, cold and hot blast.

Mean ratio of breaking weight 1000 : 925

Mean ratio of power to resist impact 1000 : 965

In the buffery iron, the hot blast manufacture is weaker whether we
view it in its transverse strength, or its power to resist impact.
Coed Talon, No. 2, North Welsh iron.

Mean ratio of strength in a number of experiments 1000 : 1014

Mean ratio of power to resist impact 1000 : 1219

Modulus of elasticity in lbs. for a bar of one inch square.

Cold blast | Jg^ooo } l4>313,500lbs.

Hot blast {j^g}l4,322,5001bs.

Elsecar cold blast, No. 1, against Melton hot blast, No. 1,
(Yorkshire iron.)

Mean ratio of strength . . 1000 : 809

Mean ratio of power to resist impact 1000 : 858

The modulus of elasticity in all the irons are computed j but only
given in a few cases in the results.

558 British Association for the Advancement of Science.

Relative strength of hot and cold blast iron to resist a transverse
strain at different degrees of temperature.
Cold blast 949-6 at 32°. Hot ditto 919-7, Mean.
Ratio of strength, 1,000 : 977*6.
Power to resist impact, 1,000 : 1,039.
Cold blast 7481 at 191°. Hot ditto 823-6.
In these experiments it appeared that the cold blast lost in strength
from 32° up to a blood-red perceptible in the dark, as 949'6 to 723'1 ;
whereas in the hot blast the strength is not so much impaired, being
as 917*7 at the freezing point, and 8297 when perceptibly red in the
dark.

In all former experiments on the transverse strain of cast iron it has
been assumed, that the elasticity remained perfect up to one-third the
breaking weight. In pursuing these experiments, discrepancies were
noticed, and results widely different to those generally received were
observed. It was found that one-seventh, and in some cases, one-
eighth the breaking weight was sufficient to produce a permanent set.
These facts induced an extended series of experiments, principally to
determine what load was necessary to effect a permanent set ; and,
if such weight, continued for an indefinite time, would break the bar.
It became a question of great importance to know, if a weight having
once impaired the elasticity, would or would not, if continued, increase
the deflection. The inquiry therefore, was — To what extent can cast
iron be loaded without endangering its security ? To solve this question
ten bars of hot and cold blast, differently loaded, were placed upon a
frame, to ascertain the amount of deflection at stated periods, and to
determine what was necessary to break the bars with their respective
loads.

Inches.
In the cold blast, with a load of 280 lbs., the de-
flexion increased in 103 days from 1*025 to 1*033

Hot blast, ditto from 1-173 to 1-197

Coldblast,withaload of 336 lbs., increased in 105

days from 1-344 to 1-366

Hot ditto, from 1-573 to 1627

Cold, with a load of 392 lbs., increased the deflec-
tion in 108 days, from 1-786 to 1-843

Hot, ditto from 1-891 to 1-966

Cold blast, with a load of 448 lbs., continued to increase in deflection
and ultimately broke, after sustaining the weight 35 days. All the
bars from the hot blast broke in the act of loading them with the
above weight, 4481b.

Mr. Fairbairne stated, that all the irons were made of the same ma-
terials, and under the same circumstances. The irons were of fifty
6orts.

Mr. Cottam inquired as to the elastic forces. Dr. Young and Mr.
Tredgold had found that the strength of the material would fail if
loaded beyond its elastic force : he wished to know whether the loads
had been more or less than 850 lbs. to the foot. Mr. Fairbairne stated
that some of the loads were more, some less, and that a weight of 280

Intelligence and Miscellaneous Articles. 559

'o

lbs. produced a permanent set of an inch square bar. The President
remarked that the calculation as to elastic forces was scarcely to be
confided in. Mr. Fairbairne in answer to another question, stated that
the hot blast iron was the more flexible and better capable of bearing
impact ; but that all the results of impact had been taken from calcu-
lations founded on cold blast iron. Mr. Fairbairne stated that the cry-
stalline appearance was finer in hot than in cold blast. There were
no experiments made on the loss by remelting, and none on wrought
iron, — all on cast iron. In reply to Mr. Cottam, he mentioned that
all the Scotch irons had no cinder j the composition of the others they
did not know. Great difficulty had been experienced on this point,
because the different manufacturers were unwilling to give information.
— Mr. Guest professed on his part the fullest readiness. — Some con-
versation took place with regard to the peculiarity of appearance in
the broken bars. The President remarked, that when a rectangular
bar of any substance is exposed either to fracture, or even to temporary
deflexion, a similar appearance was found : this was known from the ex-
periments on glass by polarized light. Mr. Fairbairne in assent, said the
crystals were always more compact in the edge than the centre. Mr.
Webster inquired whether the elastic weight was always less than one-
third of the breaking weight. Mr. Fairbairne said, always — and after-
wards replied to a question from Mr. Guest, that the Scotch hot blast
iron showed agreater comparative strength as compared with cold blast,
but that they had made no experiments on South Welsh iron. There
was a perceptible permanent set from 280 lbs,, the experiments being
of from five to ten minutes in duration, and it being possible to judge
the deflection to the 1000th part of an inch. — Mr. Webster said it had
been found that the first set was owing to the breaking of the first crust}
and that beyond the first permanent set up to the elastic limit, the de-
flexion increases exactly as the weight. Some further conversation
ensued, in which Mr. Smith and others took part, when Mr. Guest sug-
gested the propriety of further continuing these researches, to which
the President agreed, and suggested a recommendation to that effect
from the committee of the section to the General Committee. Athe-
naum, No. 516.

LXXXI. Intelligence and Miscellaneous Articles.

GASEOUS DIFFUSION.

THE following experimenthas recently been made in the laboratory
of Prof. Draper, of Hampden Sidney College, Virginia, and com-
municated to us by him $ it is a good illustration of the endosmosis of
gases, and is well adapted for a class-room experiment.

Take a two-ounce phial with a wide mouth, and having made a solu-
tion of soap in water of the consistency of a viscid lather, dip one of
the fingers into it, and pass it over the mouth of the phial j this will
leave a thin plane film stretched across it. Place over the phial thus
arranged a jar of protoxide of nitrogen, in the course of a few seconds
the horizontally of the film will be disturbed j it will become convex,
and at the end of a minute and a half or two minutes, it will form

560 Intelligence and Miscellaneous Articles.

the greater part of a sphere two inches in diameter, the colours of
which are brilliant.

The extreme rapidity with which gases pass through films of wa-
ter, has afforded in the hands of the same chemist a good method of
determining the condition of equilibrium and law of the transit of
gases. A series of papers communicated during the past and present
years to the American Journal of Medical Science, and Journal of the
Franklin Institute, contain a development of these laws. An illus-
tration from these researches will give an idea of their result.

In an atmosphere containing 190 measures of nitrogen gas, a soap
bubble was expanded containing 190 measures of protoxide of nitro-
gen. The bubble collapsed with great rapidity, and at the end of
three minutes its contents were found to be 35 measures, the atmo-
sphere around it being 34?1 measures. On analysis it was found that
the constitution of the gas within and without the bubble was iden-
tical, one half being the protoxide and the other half being nitrogen.

By thus measuring and analysing the contents of bubbles and the
atmospheres around them, the general law of equilibrium was proved
to be, that motion only ceased when the chemical composition on both
sides of the barrier had become alike.

CHLOROSULPHURETS OF LEAD, COPPER, BISMUTH, AND ZINC.

M. Reimsch, on passing sulphuretted hydrogen into a liquor con-
taining lead and acidulated with muriatic acid, obtained a blood-red
precipitate, which was collected on a filter, became of a red brown
colour, and when heated on charcoal with soda gave a globule of
lead. On leaving the precipitate a longer time in the liquor, and
adding more sulphuretted hydrogen, or on continuing a current of
this gas, the precipitate became black sulphuret. Free muriatic acid
appeared to be requisite to the production of the red-coloured preci-
pitate ; for a neutral solution of chloride of lead, or salts of lead with
excess of acid treated with sulphuretted hydrogen, always gave the
usual black precipitate. M. Reimsch satisfied himself that the pro-
duction of the red precipitate was always owing to nitric acid contain-
ed in the muriatic acid, and consequently to chlorine, and on using
muriatic acid free from nitric acid he obtained a yellow precipitate.
In order to produce the red precipitate, dissolve half a drachm of
neutral acetate of lead in seven ounces of cold distilled water ; add to
this solution, constantly agitating, seven drachms* of nitromuriatic
acid which has some days been prepared, by mixing two parts of con-
centrated muriatic acid with one part of concentrated nitric acid j
pass quickly through the solution a current of sulphuretted hydrogen,
which is to be discontinued as soon as the reddish yellow deposit has
become of a perfect cinnabar red. The yellow precipitate is obtained
by adding to the above-described solution of lead, seven drachms of
muriatic acid free from chlorine, taking care to agitate them well.
The following experiments show the nature of these precipitates.

The Red Precipitate. — If this be boiled in water, it passes from the
granular state to that of a bulky red-brown powder; this suffers no
further change, and may be dried at 100° Fahr. without altering its

M. Quevenne on Potygalic Acid. 561

colour. The filtered solution contains chloride of lead, and gives with
nitrate of silver a copious precipitate of chloride of silver.

It dissolves perfectly in nitric acid with the disengagement of ni-
trous acid, and the separation of a little sulphur. Nitrate of silver
added to this solution also gives a precipitate of chloride of silver.

If it be heated by the blow-pipe on charcoal, it fuses, and disen-
gages sulphurous acid. Part of the lead is quickly reduced, whilst the
chloride of lead is volatilized in a white smoke.

When the precipitate, separated from the chloride of lead by ebul-
lition, is heated in a glass tube, it becomes black, disengages sulphur
and sulphuretted hydrogen, and then fuses into a brown mass, which
crystallizes on cooling.

Yellow precipitate. — This behaves in the same way as the red j ex-
cept that when the chloride of lead is dissolved by boiling in water, it
is converted into black sulphuret of lead, which when heated in a
glass tube does not disengage either sulphur or sulphuretted hydro-
gen.

These results explain the difference which exists between these two
precipitates. As by the action of the chlorine or of the aqua regia
upon the sulphuretted hydrogen, hydrochloric acid is produced and sul-
phur set free, the latter combines with the sulphuret of lead, formed
at the same time, to produce sulphuretted sulphuret of lead, analo-
gous to that obtained by adding quintosulphuret of potassium to a so-
lution of lead, and this body combining with the chloride of lead,
gives the double compound of kermes colour, while the yellow preci-
pitate is merely a compound of sulphuret and chloride of lead, which
is decomposed by boiling in water.

According to the experiments of M. Reimsch, copper and bismuth
appear to form similar combinations. A solution or copper, acidified
with hydrochloric acid, gave with sulphuretted hydrogen a deep green
blue precipitate, which when washed with water till free from uncom-
bined muriatic acid, and dissolved in nitric acid, gave chloride of sil-
ver on adding the nitrate. The same effect takes place with precipi-
tated bismuth ; except that it cannot be obtained pure, on account of
the difficulty of washing it.

Zinc, which is generally admitted not to be precipitable from its
acid solutions by sulphuretted hydrogen, is however thrown down by
it from a solution of the chloride rather strongly acidified by hydro-
chloric acid. The precipitate obtained is a compound of sulphuret
and chloride of zinc. It dissolves in dilute sulphuric acid with a strong
disengagement of sulphuretted hydrogen ; but when subjected to ebul-
lition, the solution yields an abundant precipitate of chloride of silver
with the nitrate. — Journal de Pharmacie, Mai, 1837.

POLYGALIC ACID.

M. Quevenne prepares this substance by digesting powdered poly-
gala in alcohol of specific gravity 0*85 till it is exhausted. The greater
part of the spirit is to be distilled, and the syrupy residue is to be
treated with aether to remove the fatty matters. On standing, a pre-
cipitate is formed in the liquid ; this is 1o be separated bv the filter

Third Series. Vol. 1 1. No 70. Dec. 1837. 4 C

562 Intelligence and Miscellaneous Articles.

and mixed with water: to the turbid solution thus obtained, a little
alcohol is to be added ; this facilitates the formation of a whitish pre-
cipitate, which is impure polygalic acid. The liquor is to remain at
rest for several days in order that the precipitate may form perfectly ;
the supernatant liquor, which contains extractive matters and a little
polygalic acid, is to be poured off. The polygalic acid is to be allow-
ed "to drain on the filter, and while moist is to be dissolved with the
aid of heat in alcohol of specific gravity 0837. The solution is to be
Doiled with animal charcoal purified by hydrochloric acid, and by cool-
ing a fine white pulverulent precipitate is obtained, which is pure po-
lygalic acid.

The properties of this acid are, that its smell resembles that of
saponin, but is much weaker ; its taste is acrid, and it is hot in the
throat j in very small quantities it excites violent sneezing; it is so-
luble in water, the solution reddens litmus, and it froths much when
shaken ; when boiled with potash, the solution yields a gelatinous
precipitate on the addition of hydrochloric acid ; sulphuric acid pour-
ed into the solution when boiling also gives a gelatinous precipitate,
and a rose colour appears on the sides of the capsule j nitric acid
used in the same way does not yield a gelatinous precipitate, but on
cooling it gives a yellow one ; but neither acetic, citric, nor oxalic acid
produces any precipitate. Tincture of galls gives a dirty white pre-
cipitate. Polygalic acid when saturated with an alkali gives no pre-
cipitates with metallic salts, except the acetates of lead and the pro-
tonitrate of mercury.

The mean of these experiments gave as the composition of this

acid Hydrogen 7*529

Carbon 55-704

Oxygen 36767 100.

Journal de Phar made, June. 1837.

MODIFIED POLYGALIC ACID.

M. Quevenne'gives this name provisionally to the substance obtain-
ed by the action of certain acids upon polygalic acid.

In order to prepare it four parts of this acid were mixed with about
30 times its weight of concentrated hydrochloric acid. After 24 hours'
digestion, the gelatinous mass was diluted with water, and the whole
was thrown upon a filter, and washed with distilled water till it ceased
to act upon nitrate of silver. The precipitate thus washed and dried
was a grey friable mass ; it was boiled in alcohol of sp. gr. OS 1 7,
which gradually dissolved it, leaving a small quantity of gray powder
unacted upon. The filtered solution heated by a water-bath precipitated
some white flocks on cooling. If a sufficient quantity of water be
added, a gelatinous mass is precipitated, and the same effect is pro-
duced by the spontaneous evaporation of the spirit.

By evaporation to dryness the modified acid is obtained in yellowish
white, brittle, irregular fragments ; it has at first but little taste, but
soon becomes decidedly bitter ; when mixed with water it did not
swell in 24 hours. It is slightly soluble in water. The solution does
not redden litmus.

M. Gaudin on the artificial production of Rubies. 563

A portion of this acid was dissolved in alcohol of sp. gr. *915. This
solution had the following properties : it reddened litmus paper, and
precipitated the following salts; the proto-and persulphate of iron, ni-
trate of silver, acetate and subacetate of lead, the chlorides of barium,
lime, and platin urn , but not that of magnesium ; and sluphate of copper ;
the aqueous solution of tannin formed a light precipitate. The aqueous
solution of the acid precipitates the same salts. The solution exposed
to the air evaporated without giving any traces of crystallization.
Another spirituous solution of this acid, saturated with potash, left by
spontaneous evaporation a very bitter white mass, in which no trace
of crystallization could be observed.

Concentrated sulphuric acid causes this acid to impart a weak violet
tint to water.

This modified acid considerably resembles the oxalic acid of M. Fres-
ny, [differing only in two of its properties ; that of gelatinizing under
peculiar circumstances, and of giving a bitter compound with potash.
These differences are constant, by whatever mode the acid may have
been prepared. — Ibid.

ARTIFICIAL PRODUCTION OF RUBIES.

A few months since M. Gaudin presented to the Academy of
Sciences of Paris a note, in which he announced his having been able
to produce rubies in considerable quantities by a process of which he
has given merely a sketch.

In order to obtain these substances analogous to rubies, M. Gaudin
uses a platinum blowpipe of a single piece, formed of two hollow con-
centric cylinders, communicating by one of the extremities, one with
a reservoir of hydrogen, the other with a reservoir of oxygen j the
two other extremities are pierced with convergent openings, so as to
effect in a great degree the mixture of the gases.

It is well known that alumina is fusible with the oxygen and hy-
drogen blowpipe j but no one before M. Gaudin had endeavoured to
melt this earth into globules several millimetres in size. Having sub-
mitted a piece of potash alum to the action of his blowpipe, he ob-
tained a perfectly round and limpid globule The platinum tube being
perforated and melted at several places, he obtained after the cooling,
instead of a limpid spheroid, an opake elongated globule, and covered
internally with crystals, which may be referred to the cube or to the
rhombohedron. These crystals scratch- rock crystal, topaz, garnet, and
spinelle; with regard to hardness, therefore, they agree with the ordi-
nary ruby. They appear to be composed solely of alumina, the potash
volatilizing at the high temperature to which the alum is submitted.

Having obtained an apparatus stronger than the one first used, he
made an experiment with some ammoniacal alum mixed with from
4 to 5 thousandths of chromate of potash ; the whole being previously
calcined, he gave it the form of a spherical cup, in order to obtain a
maximum effect, by directing the flame to the concave part. In a few
moments the inner surface of this cup was covered with globules of a
beautiful ruby-red colour, slightly translucid, and some of which ex-
hibited the form and cleavage of the ruby.

M. Malaguti, who had occasion to analyse these globules, found

4C2

564- Intelligence and Miscellaneous Articles.

them to bo composed of 97 parts alumina, one of oxide of chrome,
and two parts of silica and lime ; which composition is analogous lo
that of the ruby. — Comptes Rendus, August, 1837, p. 325.

THEORY OF ORGANIC COMBINATIONS.

M. A. Laurent states that his theory of organic combinations had
given him the means of predicting beforehand, the existence of cer-
tain compounds which have since been obtained j and that he has
also been able, knowing the composition of a body, to arrive without
doubt at the process by means of which it may be obtained. In proof
of the latter, he cites the preparation of cenanthic acid, and that of
the aether of this acid*, which he had been able to predict without any
other data than the composition of the acid, and without any other
guide than the laws laid down in the theory which he had submitted
to the judgement of the Academy. — Comptes Rendus, August, 1837,
p. 212.

A NEW ORGANIC ACID.

M. Peligot has read to the Academy of Sciences some observationa
on cane sugar, and on a new acid derived from the action of alkalies
on sugar of starch.

It is well known that there exist two distinct varieties of sugar :
one of them is common sugar, extracted from the cane, beet-root, and
the maple ; the other occurs in grapes and diabetic urine, and is formed
when starch, lignin, or sugar of milk is treated with dilute sulphuric
acid. It is also known that, influenced by various circumstances, com-
mon sugar may be converted into sugar identical with that of starch.

Among the differences which exist between the two kinds of sugar,
one of the most prominent (says M. Peligot) is in my opinion that
which is observed when these bodies are put in contact with alkaline
bases.

Common sugar, when added to potash, lime, or barytes, combines
with these bases, and acts towards them the part of a true acidf : by
boiling a mixed solution of barytes and sugar, I obtained by direct
action a crystallized compound of these two bodies j the analysis of
saccharate of barytes, and other analogous salts, proves that the sugar
does not undergo any particular modification : on decomposing the
saccharates by weak acids, the sugar reappears with its usual properties.

The case is entirely different with sugar of starch j the alkalies effect
an essential alteration in it. On putting lime or barytes into a solu-
tion of this sugar, even cold, 1 observed that after a certain time these
bases had lost their alkaline properties, and were saturated with a
new and very powerful acid, which is formed by simple contact with
the sugar, and which immediately unites with the alkalies, and forms
perfectly neutral salts. This acid may be still more readily obtained
by putting dry sugar of starch, fused at 2 12°, in contact with crystal-
lized hydrate of barytes. Vivid reaction takes place almost immedi-
ately; the mixture swells, the temperature rises very much, and in a

* See Lond. and Edinb. Phil. Mag., vol. x. pp. 417, 418, 422.
f See the present volume, p. 152.

M. llegnault on Sulphonaphthalic Acid. 565

few seconds the sugar is transformed into acid. The barytic salt is
then dissolved in water, and the acid is precipitated by means of a
solution of subacetate of lead, to be gradually added, in order first to
separate a brown colouring matter which arises during the reaction,
at least when operating in contact with the air. The last precipitate
obtained is colourless, and contains the acid in the state of subsalt j
it may then be separated by the usual means.

Besides this acid, another non- volatile body is produced, which pos-
sesses the property of immediately reducing, when cold, the salts of
silver and of mercury.

The very easy formation of an acid, by the contact of sugar of starch
or of grapes, with bases (M. Peligot observes), shows how proper it
is to avoid the employment of too much lime in the purification of
the beet-root juice j for although lime does not alter the sugar, it
acts, when in excess, upon the sugar analogous to that of grapes, into
which common sugar is easily converted by the influence of heat, acid,
or fermentation. There are therefore two difficulties to be avoided;
these may be apprehended at the same time, — the intervention of
acids which decompose the sugar intended to be extracted, and the
effects of the alkalies which act upon the sugar of starch resulting from
this decomposition. — L'Institut, AoHtt 1837.

SULPHONAPHTHALIC ACID.

It was first observed by Mr. Faraday*, that when concentrated sul-
phuric acid was made to act upon naphthalin, two acids were pro-
duced, forming salts with barytes which were distinguished by their
different solubility. Mr. Faraday considers these acids as formed by
the direct combination of sulphuric acid with naphthalin j this was at
first admitted by all chemists. More lately, and since the researches
of M. Mitscherlich on the action of sulphuric acid upon benzon, it has
been suspected that the composition of sulphonaphthalic acid might
be analogous to that of sulphobenzic acid, especially as the analyses of
Mr. Faraday and MM. Liebig and Woehler did not agree well with their
theoretic formula.

M. Regnault has endeavoured to clear up this subject j he has se-
parately examined the action of common concentrated sulphuric acid,
and that of the anhydrous acid upon naphthalin: the following are some
of the results which he obtained. Sulphuric acid combined with one
atom of water formed only one acid compound, which is separable
from the excess of sulphuric acid by means of carbonate of barytes.
The sulphonaphthalate of barytes, obtained by the cooling of a hot
saturated solution, had the form of small crystalline tufts ; but, by
the spontaneous evaporation of a cold solution, it crystallizes in ag-
gregated small irregular tables. This salt, which had been dried at
356° Fahr., gave by analysis O0 H14. S* O5 BaO; that is to say,
common sulphuric acid produces on naphthalin the same reaction that
the anhydrous acid does upon benzon. Two atoms of the hydrogen
of the naphthalin remove one atom of oxygen from two atoms of sul-

* Mr. Faraday's paper on this subject will be found in Phil. Mag. First
Series, vol. Ixvii. p. 326.

566 Intelligence and Miscellaneous Articles.

phuric acid, and the hyposulphurie acid formed combines with the mo-
dified naphthalin.

The crystallized sulphonaphthalate of barytes contains an atom of
water, which it does not lose in vacuo j it is slightly soluble in water:
100 parts of water at 60° Fahr. dissolve 1*13 of this salt, and at 222°
Fahr. 4*76 parts.

M. Reguault has analysed several other sulphonaphthalates, the
composition of which indicated the same formula as the sulphonaph-
thalate of barytes. The oxide of lead forms with sulphonaphthalic
aoid a neutral salt and several subsalts ; the latter are obtained by
boiling massicot in the neutral solution of sulphonaphthalate j the
sulphonaphthalate of potash crystallizes in very brilliant spangles :
it contains one atom of water.

Free sulphonaphthalic acid is obtained by decomposing sulpho-
naphthalate of lead by means of sulphuretted hydrogen. This acid is
extremely soluble in water and in alcohol, and by evaporation it is ob-
tained in an irregular crystalline mass, and it is deliquescent in moist
air. Its taste is very sour, astringent, and metallic ; it readily fuses,
becomes black, and if the temperature is increased, the smell of
naphthalin begins to be perceptible; when more strongly heated it
swells and leaves a very brilliant and bulky coal. The acid dried in
vacuo contains three atoms of water of crystallization ■ it loses part of
this water by the action of heat, but it decomposes before it is entirely
dissipated.

Anhydrous sulphuric acid exerts a much more complicated action
upon naphthalin; there are formed two acids producing soluble salts
with barytes, and an insoluble matter. One of these acids is the com-
mon sulphonaphthalic acid ; the other is a peculiar acid, which is di-
stinguished from the first by the greater solubility of its salts. The
salts formed by this acid cannot be obtained in crystals ; they remain
in an amorphous mass after the evaporation of the water, and there is
no certainty as to their purity. Several analyses of the barytic salt,
purified by solution in pyroxylic spirit, indicated its composition to be
C14 H10. 2 SO3 BaOj but it does not appear how this is deducible
from naphthalin. The insoluble matter, produced at the same time as
the preceding acid, is a viscid mass, which appears to be a mixture of
several substances. It has not been minutely examined. M. Re-
gnault intends to continue his researches. — Ibid.

CONSERVATION OF LIVING PLANTS DURING LONG VOYAGES.

Extract from a letter from M. d'Eaubonne.

" Having constructed a case so that the air could not enter, by
carefully fixing several bands of linen on all the joints with a glue
not liable to alteration, 1 prepared," says M. d'Eaubonne, "with
potters' clay, cow dung, and water a somewhat liquid mortar, in
which I immersed the roots, having previously coated the stem j
this being done, I covered them with moss and placed them in the
case, filling the intervals carefully with straw, so that no friction
might take place from the pitching or rolling of the vessel. I closed
the case ; and, after having used the same precautions for the exte-
rior joints as for the inner ones, I had it placed in the hold of the ves-

Collection in the Rev. N. S. Heineken's paper. 567

sel which was to carry it to the isle of Mauritius. The vessel ar-
rived safe, the case was disembarked and opened before the customs,
and instead of dry and sapless wood as was expected to be found,
trees covered with leaves and flowers, much to our surprise were to
be seen. These trees were afterwards distributed among several in-
habitants of the colony." — Comptes Rendus, August, 1837, p. 260.

SHOOTING STARS.

M. Arago announces that an extraordinary appearance of shooting
stars took place in the night of the 10th to the 1 1th of last August.
His eldest son, who is no astronomer, and one of his friends, walking
in the garden of the Observatory, counted not less than 107 between
a quarter past 1 1 and a quarter past 12. From 12h 37m to 3h 26m at
the beginning of the twilight, MM. Bouvard and Laugier, astrono-
mical students, observed 184 of these meteors. The greater number
seemed to take a direction towards Taurus, as was to be expected
from the direction of the motion of translation of the earth. — Comptes
Rendus, August, 1837, p. 184-.

CORRECTION IN THE REV. N. S. HEINEKEN S PAPER ON THE
SHOCK-MULTIPLIER.

To the Editors of the Philosophical Magazine and Journal,
Gentlemen,
I shall feel obliged if you will have the goodness to make the
following correction in the paper relating to the " Shock Multi-
plier" inserted at page 460 of the last Number of the Philosophical
Magazine. The passage commences at the fifth line from the bot-
tom of the page, and should stand thus : " If a wire have a moist
sponge attached to one extremity while the other is connected with
one of the poles of a battery, and the hand grasp the moist sponge;
— and if the other pole'of the battery be connected by a wire with
N, the other hand grasping a second sponge connected with the
wire O, a rapid succession of shocks will, &c." I am, &c.

N. S. Heineken.

METEOROLOGICAL OBSERVATIONS FOR OCTOBER 1837.
Chiswick. — Oct. I. Overcast. 2. Slight rain. 3. Foggy. 4. Over-
cast: fine: clear and cold. 5. Foggy: clear. 6. Heavy rain: clear.

7. Foggy: very fine. 8. Overcast and fine. 9—14. Very fine. 1 5. Slight
fog: fine. 16. Overcast. 17. Foggy : overcast and fine. 18. Overcast.
19, 20. Foggy : very fine. 21. Foggy : overcast. 22. Rain. 23. Fine: rain.
24. Heavy : rain. 25. Clear. 26. Fine. 27. Cloudy : rain. 28. Fine :
rain. 29. Very clear : fine : overcast. 30. Rain. 31. Overcast and
fine : clear and cold at night.

Boston.— Oct. 1. Rain. 2. Fine. 3. Foggy : rain p.m. 4. Fine:
rain early a.m. 5. Fine. 6. Cloudy: rain early a.m. 7. Fine.

8. Cloudy: rain p.m. 9. Cloudy. 10. Fine. 11, 12. Cloudy.
13—15. Fine. 16, 17. Cloudy. 18, 19. Fine. 20. Fine: rain p.m.
21. Foggy. 22. Fine. 23. Cloudy. 24. Cloudy : rain p.m. 25. Cloudy:
rain a.m. 26. Fine: ice this morning : rain p.m. 27. Stormy : rain
early a.m. 28. Cloudy: rain a.m. 29. Fine: rain a.m. and p.m.
30. Rain : rain and stormy p.m. 31. Fine.

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INDEX to VOL. XI.

A CIDS: — acetic, 51 3; ampelic,406; an-
hydrous camphoric, 221 ; anhydrous sul-
phuric and sulphurous, 321, 566; arse-
nious, 482 ; camphovinic, 221 ; chromic,
489; formic, 399 ; fumaracid, 164; gal-
lic, 323; iodic, 219; lampic, 512; anew
organic, 564; nitric, 554; oxalhydric,
142; polygalic, 561; sulphonaphthalic,
565.

Aerial currents, on Mr. Whewell's in-
struments for registering, 474.

./Ethereal oils, preparation of, 159; ele-
mentary constituents of, 161.

Addams (R.) on the action of cold air in
maintaining heat, 446.

Africa, on the ring money of, 132.

Algaj, their mode of generation, 385.

Alkalies and metallic oxides, on the com-
binations of sugar with the, 152.

Alkalies, vegetable, on the action of iodine
upon the, 216.

America, North, on the ancient state
of, 201 ; observations on the western
coast of, 91.

Ammonia with anhydrous salts, on the
combinations of, 141.

Ampelicacid, 406.

An.pelin, on, 407.

Amvlum, experiments on, 442.

Anatifa vitrea, on its occurrence on the
Irish coast, 135.

Andrews (Dr.) on the action of nitric acid
on certain metals, 554.

Anemometer and rain gauge, on a new re-
gistering, 476.

Anhydrous camphoric acid, 221 ; sulphuric
and sulphurous acids, a combination of,
321.

Animal?, on the hereditary instinctive pro-
pensities of, 96 ; on the crystalline lenses
of, after death, 97.

Arago (M.) on shooting stars, 567.

Arsenious acid, solubility of, 482.

Ashes of plants, on structure in the, 13.

Astronomy: — aurora borealis, 194; on
shooting stars, 268, 567.

Atmosphere,on the constitution of the, 195;
on the carbonic acid in the, 225.

Atmospheric pressure, fluctuations of the
height of high water due to changes in
the, 195.

Aurora borealis, phenomena of, 194.

Babel and Babylon, on the distinction be-
tween, 68.

Third Series. Vol. 11. 4

D

Bacillaria?, doubtful nature of the, 387 ;
notice of new discoveries of Ehrenberg
respecting the, 448.

Baggy Point, on the raised beaches of, 117.

Baker (Lieut.) on the fossil jaw of a gi-
gantic quadrumanous animal, 33.

Banffshire, on some elevations of the coast
of, 209.

Barlow (P.) on the electro-magnetic con-
ducting power of wires, and on the ef-
ficiency of the galvanometer for deter-
mining the laws of its variation, 1.

Barlow (W. H.) on different modes of il-
luminating light-houses, 94.

Baryta and strontia, on the hydrates of,
301.

Barytes, carbomethylate of, 143.

Baryto-calcite, on the right rhombic, 45.

Becquerel (M.),on siliceous and calcareous
products, 403.

Beke (C. T.) on the extent of the Persian
Gulf, and on the distinction between
Babel and Babylon, 66 ; on the com-
plexion of the ancient Egyptians, 344.

Bennett (F. D.) on the anatomy of the
spermaceti whale, 1 96.

Bennett (G.) on a species of glaucus, 118.

Berberin, 338.

Bermuda, on the carbonic acid in the at-
mosphere of, 225 ; meteorological ob-
servations taken at, in 1836, 449.

Berzelius' (J. J.) reply to Dr. Hare's re-
marks on his chemical nomenclature,
179.

Binks (C.) on the phenomena and laws
of action of voltaic electricity, and on
the construction of voltaic batteries, 68.

Bismuth and iron, on the peculiar voltaic-
inactivity of, 544.

Bismuth, chlorosulphuret of, 560.

Bondsdorff ( Dr.) on the solubility of oxide
of lead in water, 221.

Bonomi (Mr.) on the ring money of Afri-
ca, 132.

Books, new, notices respecting, 481, 548.

Botanical alliances, origin of the, 247.

Botanical classification, on the present state
of, 48.

Botany : — on structure in the ashes of
plants, 13, 413; on botanical classifica-
tion, 48, 137 ; Anatifa vitrea, of the Irish
coast, 135; progress of phytochemistry

f" i reference to the physiology of plants,
56 ; origin of botanical alliances, 247 ;

570

1 N D E X.

progress of vegetable physiology, 381,
435, 524; botanical affinities of Oro-
banche, 409; composition of vegetable
membrane and fibre, 421 ; combination,
structure, and contents of the cells of
plants, 435; Bacillariae, 448 ; cow tree of
South America, 452 ; on the system of
circulation in vegetables, 528 ; milk ves-
sels of the Euphorbiaceae and Asclepia-
deae, 529 ; internal structure of the wood of
palms, 553 ; on the conservation of living
plants, 566.

Bowerbank (J. S.), account of a deposit
containing land-shells, at Gore Cliff,
Isle of Wight, 103.

Breccia and iodine, 216.

Breccia, hydriodate of, 216; iodate of,
217.

Brett (R. H.) on the bromo-cyanide and
chloro-cyanide of potassium and mer-
cury, 340.

Brewster (Sir D.) on the connection be-
tween the phaenomena of the absorption
of light and the colours of thin plates,
95 ; on the crystalline lenses of animals
after death, 97.

British Association, meeting at Liverpool,
396, 474, 551.

Bromhead (Sir E. F.) on the present
state of botanical classification, 48 ; re-
marks on his paper on botanical classifi-
cation, 137 ; on the origin of the bota-
nical alliances, 247.

Bromo-cyanide of potassium and mercury,
340.

Brooke (II. J.) on the identity of phacolite
and levyne with chabasie, 12; on mu-
rio-carbonate and muriate of lead, 175;
on the crystalline form of pyrosmalite,
261.

Buckland (Dr.) on the keuper sandstone
in the upper region of the new red sand-
stone formation, 106.

Bulletin, biographical, 481, 548.

Buzareingues, on the distribution and mo-
tion of the sap in plants, 526.

Caldcleugh (A.) on the elevation of the
strata on the coast of Chib", 98.

Camphoric aether, 221 ; acid, anhydrous,
221.

Camphovinic acid, 221.

Carbomethylate of barytes, 143.

Carbonate of lime, occurrence of, on saxi-
frage leaves, 445.

Carbonic acid in the atmosphere, on the,
226.

Carbovinate of potash, 320.

Carp, gigantic, 223.

Cautley (Capt.) on the remains of a qua-
drumanous animal found in the Sewaliks,
208 ; on a fossil monkey from the ter-
tiary strata of the Sewalik Hills, 393.

Cellular membrane, composition of, 440.

Chabasie, identity of phacolite and levyne
with, 12.

Chemical philosophy and nomenclature,

on certain points of, 176.
Chemistry and mineralogy, section of, 554.
Chili, on the elevation of the strata on the

coast of, 98, 100.
Chloro-cyanide of potassium and mercury,

342.
Chlorosulphurets of lead, copper, bismuth,

and zinc, 560.
Chorion, mode of origin of the, 93.
Chromic acid, its action upon silver, and

combinations with the oxide of silver,

489.
Cinchonia, iodate of, 217; elementary

composition of, 335.
Citric aether, analysis of, 139.
Clarke (Rev. W. B.) on the geology of

Suffolk, 106 ; on the geological structure

and phenomenon of the Cotentin, and of

the immediate vicinity of Cherbourg,

107.
Closteriae, mode of increase of, 386 ; form-
ation of the fruit in the, 388.
Cobalt and nickel incapable of being ren-
dered inactive, 547.
Codeia and iodine, 220.
Codeia and morphia, on a double salt of,

405.
Colours of thin plates, 95.
Colvin (Major) on the discovery of a head

of the Sivatherium, 208.
Combinations, organic, theory of, 564.
Condensing tube of Liebig, 57.
Connell (A.) on the analysis of gadolinite,

143; on the nature of lampic acid, 512.
Cooper (J. T. ) on the colouring matter of

the ruby glass, 137.
Copper, chlorosulphuret of, 560.
Cornwall, Royal Geological Society of,

478.
Cotentin, on the geological structure and

phaenomena of the northern part of the,

107.
Coumarine, composition of, 162.
Cow tree of South America, on the, 452,

530.
Crystalline reflexion and refraction, on the

laws of, 134.
Crystals, occurrence of, in plants, 443 ; on

the optical theory of, 461, 537.
Crustacea, on the development of, 552.
Cuba, on the geology of Holguin in, 17 ,

coral rock of, 31.
Cunningham (J.) on an improved mode of

constructing magnets, 196.
Cusconin, preparation of, 335.
Cutch, on the geology of, 107.
Cuvier (M. F.) on the Jerboas and Ger-

billas, 394.
Dalton (Dr. J.) on the constitution of the

atmosphere, 195; on the sulphurets of

lime, 195; notice relative to the theory

of the winds, 390.
Daniell (J. F.), further observations on

voltaic combinations, 89.

I N D E X.

571

Darwin (C), on proofs of recent elevation
on the coast of Chili, 100 ; on the depo-
sits containing Mammalia in the neigh-
bourhood of the Plata, 206 ; on areas of
elevation and subsidence in the Pacific
and Indian oceans, 307.
Dau ( Dr. Lui«i) on the practicability of a
north-west Arctic passage, 194; on the
velocity of the wind, 194.
Demouville on the diurnal variation of

the magnetic needle, 194.
Denmark, on some changes of level which

have taken place in, 309.
Detection of foreign matters diffused in

the atmosphere, on the, 56.
Devonshire, on the physical structure of,
311; on the subdivisions and geological
relations of its old stratified deposits,
315; Goniatites, 317.
Dew-point, on the deduction of the, from
the indications of the wet-bulb thermo-
meter, 54.
Diatomeae, doubtful nature of the, 389 ;
siliceous envelopes of the, 389 ; classifi-
cation of, 390
Diffusion, gaseous, 559.
Douglas ( Mr. ), observations on the western

coast of North America, 91.
Dove (H. W.), outlines of a general theory

of the winds, 227, 353.
Draper (Prof.) on gaseous diffusion, 559.
Dumas (M.) on carbovinate and potash,

320.
Duraod (H. M.) on the fossil jaw of a

gigantic quadrumanous animal, 33.
Dutrochet's experiments on the respiration

of plants, 536.
Earthquake in Syria, on the, 204.
Earth's surface, on the probable effect of
the transfer of pressure from one part to
another of the, 212; letter from Sir J.
F. W. Herschel in explanation of, 214.
Eaubonne (M. d') on the conservation of

living plants, 566.
Edwardsite, a new mineral, 402.
Egyptians, on the complexion of the, 344.
Electricity, on the conducting powers of
wires for, 192 ; researches into the cause
of voltaic, 274.
Electro-magnetic conducting powers of

wires, 1.
Emetine, preparation of, 165.
Emmet (Prof.) on the preparation of

formic acid, 399.
Emmett (Lieut. -Col.) on the carbonic

acid in the atmosphere, 225.
Entomology : — on the temperature of in-
sects, 189; on the supposed production
of insects, 551.
Entozoa, in the stomach of the tiger, 1 28.
Equations, new method of solving, 239.
Erdman (M.) on the oxalhydric acid of

M. Guerin, 142.
Euphorbiaceae and Asclepiadea?, milk ves-
sels of the, 520.

4

Europe, experiments made in, 254 ; on the
diurnal inequality wave on the coasts of,
195.

Exley (T.) on Mossotti's theory of physic*,
496.

Fairbairne (Mr.) on hot and cold blast
cast iron, 556.

Falconer (Dr.) on a fossil monkey from
the tertiary strata of the Sewalik hills,
393.

Farre (Dr.) on the structure of the higher
forms of Polypi, 189.

Forbes ( Prof. ) on terrestrial magnetic in-
tensity, 58, 166, 254, 363 ; on the mag-
netic dip, 370; on the polarization of
heat, 542.

Forchammer (G.) on some changes of
level which have taken place in Den-
mark, 309.

Formic acid, artificial preparation of, 399.

Fossil jaw of a gigantic quadrumanous
animal, on the, 33 ; fossil monkey, 393.

Fourier (M.) on an error in his " Ana-
lyse des Equations," 38.

Fox (R. W.) on the process by which mi-
neral veins have been filled, 203 ; on the
temperature of some mines in Cornwall
and Devonshire, 520.

Fresnel's optical theory of crystals, analy-
tical reduction of, 462.

Fritsche's experiments on the pollen, 165.

Fumar acid, composition of, 164.

Fyfe (Dr.) on the use of sulphate of cop-
per for exciting voltaic electricity, 145 ;
on the employment of iron in the con-
struction of voltaic batteries, 150.

Gadolinite, analysis of, 143.

Gahn's blowpipe, modification of, 58.

Gallic acid, formation of, 163 ; on, 323.

Galvanic shock-multiplier, on the, 460.

Galvanometer, its efficiency for determi-
ning the conducting power of wires, 8;
on a thermoscopic, 378.

Gardner (Mr.) on the internal structure of
the wood of palms, 553.

Gaudichaud on the circulation of the sap
in Cissus hydrophora, 525.

Gaudin (M.) on the artificial production
of rubies, 563.

Gay-Lussac (M.) on siliceous and calca-
reous products, 403.

Geological Society, 98, 201, 307, 390.

Geology : — fossil jaw of a gigantic qua-
drumanous animal, I ; geology of Hol-
guin in Cuba, 17 ; colouring matter of
the greensand formation, 36 ; mountain
of La Silla, 25 ; land-shell limestone of
La Silla, 26 ; caves of La Silla, 29 ; coral
rock of Cuba, 31 ; elevation of the strata
on the coast of Chili, 98, 100; a deposit
containing land-shells, at Gore Cliff,
103 ; a trap dyke in the Penrhyn slate
quarries, 103 ; the strata usually termed
plastic clay, 104 ; pcology of Suffolk,
106; keuper sandstone of the new red

D2

572

I N D E X.

sandstone formation, 106 ; geological
structure of the Cotentin and Cher-
bourg, 107 ; geology of Cutch, 107 ;
physical features of Suffolk, 111 ; on
Saunton Downend and Baggy Point,
1 17 ; occurrence of Anatifa vitreaon the
Irish coast, 1 35 ; ancient state of the
North American continent, 201 ; geology
of Smryna, 202; deposits containing
Mammalia, 206 ; remains of a quadru-
manous animal, 208 ; discovery of a head
of the Sivatherium, 208 ; on some ele-
vations of the coast of Banffshire, 209 ;
a tertiary deposit near Lixouri, 209 ;
geological character of the coast of Nor-
mandy, 210; a well at Beaumont green,
in Hereford, 215; affinity of fossil
scales of fish with those of the recent
Salmonidae, 300 ; an elevation and sub-
sidence in the Pacific and Indian oceans,
307; changes of level in Denmark, 309;
physical structure of Devonshire, 311 ;
upper formations of the new red system
in Gloucestershire, Worcestershire and
Warwickshire, 318; fossil monkey, 393 ;
phaenomena in Christiania, 555.

Gigantic animal, on the fossil jaw of a,
S3.

Gloucestershire, on the upper formations of
the new red system in, 318.

Gore Cliff, account of a deposit containing
land-shells at, 103.

Graham (Prof.) on the constitution of
salts, 397.

Grant (Capt.) on the geology of Cutch, 107.

Gray (Mr.) on the supposed production of
insects, 551.

Great ltunn, an account of the, 1 10.

Greatheed (S. S.) on a new method of sol-
ving equations of partial differentials,
239.

Griesselich on the glands in the leaves of
Labiatae, 530.

Hamilton (W. J.) on a tertiary deposit
near Lixouri in Cephalonia, 209.

Hare (Dr.) on certain points of chemical
philosophy and nomenclature, 176; the
grounds of his deviating from the lan-
guage and arrangement of Berzelius,
177 ; on ink devoid of free acid, 324 ;
on the congelation of water by hydric
aether, 325 ; on synthesis of ammonia,
326 ; on the rotatory multiplier, 327 ;
communication respecting nomenclature,
J. J. Berzelius's reply to, 179.

Hartley (Mr.) on the corroding of iron by
salt water, 554.

Heat, on the action of cold air in main-
taining, 407, 446 ; on the polarization
of, 543.

Height, experiments on terrestrial mag-
netic intensity, particularly with refer-
ence to the effect of, 166.

Heineken (Rev. N. S.) on the galvanic-
shock multiplier, 460; correction in his
paper, 567.

Hereford, on a well at Beaumont Green,
in, 215.

Herschel (Sir J. F. W.) on the probable
effect of the transfer of pressure from one
part to another of the earth's surface, 212;
on the peculiar voltaic condition of iron,
329.

Holguin, on the geoloty of, in Cuba, 17.

Hope (Dr.) on the colours of plants, 441 .

Horner (Mr.) on some geological phaeno-
mena in Christiania, in Norway, 555.

Horner (W. G. ), new demonstration of an
original proposition in the theory of num-
bers, 456; theorem of, 457 ; obituary
notice of, 459.

Hiinefeldonthe microscopical examination
of the coloured parts of vegetables. 442.

Hunton f L. ) on the combinations of sugar
with the alkalies and metallic oxides,
152.

Hydriodate of brucia, 216, 217 ; of quina,
218.

Hydrobromate of carbo-hydrogen (methy-
lene), 221.

Hydrogen, new carburets of, 404 ; carbu-
rets of, 405.

Hydrometeors, their connection with the
variations of the temperature and of the
barometer, 359.

Infinite series, formulae for the summation
of, 41.

Insects, on the temperature of, 189.

Iodate of brucia, 217 ; of cinchonia, 217 ;
of quina, 218.

Iodic acid and morphia, 219.

Iodide of mercury, native, 143.

Iodine and brucia, 216; and cinchonia,
217; and codeia, 220; and morphia,
218 ; and quina, 218.

Ipoh or Upas poison, on the, 193.

Iron, its conversion into plumbago, 321 ;
its corrosion by salt water, 554 ; on the
peculiar voltaic condition of, 329 ; on
the strength of hot and cold blast cast,
556 ; Carron, Devon, North Welsh,
Yorkshire, 557 ; elastic forces of, 558.

Isodynamic lines, on the direction of the,
258.

Ixalusprobaton, 124; Antilope Eurycerus,
125; Antilope Philantomba, 125 ; An-
tilope Sumatrensis, 126; Antilope pal-
mata, 126.

Jablonski on the chemical process of vege-
table life, 532.

Jerboas and Gerbillas, on the, 394.

Jones (Capt.) on a cast of money current
among the Africans, 132.

Jones (T. W.) on the first changes in the
ova of the mammifera in consequence of
impregnation, and the mode of origin of
the chorion, 93.

Kane (Dr. II.) on the powder formed by
the action of water on white precipitate,
428 ; on the action of ammonia on the
protochloride of mercury, 504.

Knight (T. A.)on the hereditary instinct-

INDEX.

d/3

ive propensities of animals, 96 ; on the
supposed absorbent powers of the spon-
gioles of the roots of trees, 534.

Knox (Rev. T.) on a new rain gauge, 260.

Kcene (M. ) on a double salt of codeia
and morphia, 405.

Lampic acid, nature of, 512 ; changed into
acetic acid, 513.

Landerer on emetine, 165.

La Silla, mountain of, 25 ; land-shell lime-
stone ol, 26 ; caves of, 29.

Lassaigne ( M.) on stearic aether and stea-
rate of methylene, 487.

Laurent (M.) on the theory of organic com-
binations, 564.

Lead, on murio-carbonate and muriate of,
175 ; chlorosulphuret of, 560.

Lichens, chemical basis of the peculiar co-
lour of, 338.

Liebig on the condensing tube, 57 ; on pi-
nic acid, 164.

Light, phamomena of the absorption of,
95 ; on the propagation of, in uncry-
stallized media, 132; on the dispersion of,
477 ; solar, effects of, on vegetation, 525,
zodiacal, 194.

Light-houses, on different modes of illu-
minating, 94.

Lime, on the sulphurets of, 195.

Lindley (Dr. J.) on the botanical affinities
of Orobanche, 409.

Link on the composition of cellular mem-
brane, 440.

Linseed oil, combustion of, 324.

Lixouri, on a tertiary deposit near, 209.

Lloyd (J. A.) on metereological deductions
made at Port Louis in 1833, 1834, and
1835, 97.

Lloyd ( Prof. ) on the propagation of light
in un crystallized media, 132.

Locke (Dr. J.) on a thermoscopic galvano-
meter, 378.

Lubbock (J. W. ) on the fluctuations of the
height of high-water due to changes in
the atmospheric pressure, 195; on the
variation of the arbitrary constants in
mechanical problems, 492 ; on the wave-
surface in the theory of double refraction,
417.

MacCullagh (Mr.) on the laws of crystal-
line reflexion and refraction, 134.

Magnetic dip, on the, 370 ; observations of,
with a three-inch circle, 372.

Magnetic intensity of the earth, 58, 66,
170, 254, 363.

Magnetism, variations in the needles, 166.

Magnets, on an improved mode of con-
structing, 196.

Malaguti (M. ), analysis of citric aether, 139.

Mammalia, extinct, in the deposits of the
neighbourhood of the Plata, 206.

Mammifera, on the first changes in the ova
of the, 93.

Marquart (J. C.) on the progress of phy-
tochemistry, 156, 333; on the colours
of plants, 441.

Mathematics, 41, 239, 302, 417, 456, 461,
492, 524, 537.

Mease (Dr.) on the dry rot of ships, 192.

Mercury, native iodide of, 143.

Metals, on the action of nitric acid on, 554.

Metanaphtalcne, new carburets of, 404.

Meteorological deductions made at Port
Louis in 1833, 18:34, and 1835, 97.

Meteorological observations, 143, 223, 327,
407, 487, 567; taken at Bermuda in
1836,449.

Meteorological Table:— for May, 144;
June, '224; July, 328; August, 408;
September, 48S ; October, 568.

Meyen (J.) on the progress of vegetable
physiology, 381,435, 524 ; on the struc-
ture of the glands on the leaves of the
Labia t a-, 531.

Mineral veins, on the process by which they
have been filled, 203.

Mineralogy :— crystallographical identity
of phacolite and the Irish bipyramidal
levyne with chabasie, 12; on murio-
carbonate and native muriate of lead,
175; on the crystalline form of pyro-
smalite,261 ; account of Edwardsite, 402.

Mines, in the Savana region, discovery and
progress of the, 22 ; on their tempera-
ture in Cornwall and Devonshire, 520.

Mitchell (Dr.) on a well at Beaumont
Green, Hereford, 215.

Mohl, on the symmetry of vegetables, 383 ;
on the validity of Ehrenbergs character
for distinguishing animals and vegeta-
bles, 387.

Moore (Mr.) on the earthquake in Syria,
204.

Mornay on the inflammable milk of Eu-
phorbia phosphorescens, 530.

Morphia and iodine, 218.

Morphia and iodic acid, 219.

Morren on the respiration of plants, 537.

Morris (J.) on the strata usually termed
plastic clay, 104.

Mulder (M.) on the preparation of sul-
p buret of carbon, 221.

Murchison (R. I.) on the physical struc-
ture of Devonshire, 311 ; on the upper
formations of the new red system, 318.

Murio-carbonate and native muriate of
lead, on, 175.

Murphy (Rev. R.) on an error of M.
Fourier in his •' Analyse des Equa-
tions," 38 ; on the roots of equations, 92.

Muscular fibre of animal and organic lite,
structure of, 194.

Myrmecobius, on certain differences exist-
ing between two specimens of, 200.

New books, notices respecting, 481, 548.

Newbold (Lieut.) on the lpoh or Upas
poison, 193.

Newport (G.) on the temperature of in-
sects, and its connexion with respiration
and circulation, 189.

Newton (Sir I.) on the manuscript of,
138.

574

INDEX.

Nickel and cobalt incapable of being ren-
dered inactive, 547.
Nitric acid, its action on certain metals,

554.
Noad (H. M.) on the hydrates of baryta

and strontia, 301.
Normandy, geological character of the

coast of, 210.
Numbers, theory of, new demonstration of

an original proposition in, 456.
Oceans, Pacific and Indian, areas of ele-
vation and subsidence in the, 307.
Ogilby (W.) on some hollow-horned Ru-
minants, 124; arrangements of the Ru-
minantia, 469.
Opium, chemical history of, 335.
Optical theory of crystals, Fresnel's analy-
tical reduction of, 462.
Organic acid, on a new, 564.
Orobanche, on the botanical affinities of,

409.
Osier (Mr.) on a new registering anemo-
meter and rain gauge, 476.
Owen (R.) description of two Entozoa in
the stomach of the tiger, 128; on the
cranium of the Toxodon platensis, 205.
Oxalhydric acid of M. Guerin,on the, 142.
Oxide of lead, on the solubility of, in wa-
ter, 221.
Palms, internal structure of the wood of,

553.
Parabola, on Prof. Wallace's property of

the, 302.
Paramorphia, discovery of, poisonous pro-
perties of, 335.
Peligot (M.) on carbovinate of potash,

320 ; on a new organic acid, 564.
Pelletier ( M.) on the action of iodine upon
the vegetable alkalies, 216 ; on the ele-
mentary composition of paramorphia,
335.
Penrhyn slate quarries, on a trap dyke in

the,' 10 3.
Perameles, on a new species of the genus,

198.
Peroxide of mercury, action of ammonia

on the, 504.
Persian gulf, on the extent of the, 66.
Phacolite and levyne, identity of with cha-

basie, 12.
riilorrizin, properties of, 337.
Physeter macrocephalus, 196.
Physics, on M. Mossotti s theory of, 496.
Physiology of plants, 156, 381, 435.
Phytochemistry, on the progress of, 333.
Plants, on structure in the ashes of, 13,
413; chemistry of, 156; siliceous contents
of, 339; on the symmetry, arrangement,
and characteristics of the nature of,
383 ; on the combination, structure, and
contents of the cells of, 435 ; action of
solar light on, 537 ; on the conservation
of, 566.
Plastic clay, on the strata usually termed,
104.

Plumbago, conversion of iron into, 321.

Poison, the Ipoh or Upas, used by the Ja-
coons, 193.

Polygalic acid, 561 ; modified, 562.

Polypi, on the structure of the higher forms
of, 189.

Port Louis, meteorological deductions
made at, 97.

Portlock (Capt.) on the occurrence of Ana-
tifa vitrea on the Irish coast, 135.

Potash, carbovinate of, 320.

Potassium and mercury, bromo-cyanide
and chloro-cyanide of, 340.

Powell (Prof.) on the dispersion of light,
477.

Pratt (S.) on the geological character of
the coast of Normandy, 210.

Precipitate, white, on the powder formed
by the action of water on, 428 ; products
of the action of alkalies in excess on, 433.

Prestwich (J. jun.) on some elevations of
the coast of Banffshire, 209.

Prideaux (J.) on the deduction of the
dew-point, 54.

Protochloride of mercury, action of am-
monia otrihe, 504.

Pyrosmalite, crystalline form of, 261.

Quassin, preparation of, in a pure state, 336.

Quetelet (M.) on shooting stars, 268 ; on
the height, motion, and nature of shoot-
ing stars, 270.

Quevenne (M.) on polygalic acid, 561 ;
on modified polygalic acid, 562.

Quinia and iodine, 218.

Quinia, hydriodate of, 218; iodate of,
218; elementary composition of, 335.

Rain gauge, new, 260, 476.

Raphides, composition of, 339.

Reade (Dr.) on a permanent soap-bubble,
375.

Reade (Rev. J. B.) on structure in the
ashes of plants, and their analogy to the
osseous system in animals, 13,413; on
the composition of vegetable membrane
and fibre, 42 J ; reply to the objections
of Professors Henslow and Lindley, 424.

Regnault (M.) on sulphonaphthalic acid,
565.

Reid (Mr.) on a new species of the genus
Perameles, 198.

Reimsch (M.) on chlorosulphurets of lead,
copper, bismuth, and zinc, 560.

Resins, chemical examination of, 158.

Respiration of plants, on, 537 ; of insects,
189.

Itetingle, new carburets of, 404.

Retinnapthe, new carburets of, 404.

Retinole, new carburets of, 404.

Ritchie (Prof.) on the conducting powers
of wires for electricity, 192 ; on the heat
in metallic and liquid conductors 193.
Rive (A. de la) researches into the cause

of voltaic electricity, 274.
Robiquet (M.) on gallic acid, 323.
Rose (M.) on the combinations of ammo-

INDEX.

575

nia with anhydrous salts, 141 ; on a
combination of the anhydrous sulphuric
and sulphurous acids, 321.

Roy (T.) on the ancient state of the North
American Continent, 201.

Royal Geological Society of Cornwall,
anniversary meeting of, 478.

Royal Irish Academy, 131.

Royal Society, 89, 189.

Rubies, artificial, 563.

Ruby glass, on the colouring matter of, 137.

Ruminantia, arrangements of the, 469 ;
Camelidae, 471 ; Cervidae, 471 ; Moschi-
dse, 472 ; Capridse, 473 ; Bovidae, 473.

Saccharates, baryta and strontia, 156; po-
tassa and soda, 156.

Salmonidse, on the affinity of fossil scales
of fish with those of the recent, 300.

Salsaparin, composition and properties of,
337.

Salts, on the constitution of, 397.

San Fernando, mine of, 22.

Sap, circulation of, in Cissus hydrophora,
525 ; distribution of, in plants, 526 ; ela-
boration of, 527.

Saunton Downend and Baggy Point, on the
raised beaches of, 117.

Schoenbein (Prof.) on the peculiar voltaic
inactivity of bismuth andiron, 544.

Schulke, on the composition of amylum,
422.

Sedgwick (Prof.) on the physical structure
of Devonshire, 311.

Seed-lac, production of, 156 ; composition
of, 157.

Scwalik hills, on a fossil monkey from the
tertiai y strata of the, 393 ; on the remains
of a quadrumanous animal found in the,
208.

Shepherd (Dr.) on Edwardsite, 402.

Ships, on the dry-rot of, 192.

Shock-multiplier, correction in Heineken's
paper on the, 567.

Shooting stars, on, 268.

Siliceous and calcareous products, 403.

Silver, action of chromic acid upon, 489.

Sivatherium, discovery of a head of the,
208.

Skey (F. C.) on the structure of the mus-
cular fibre of animal and organic life, 194.

Smyrna, on the geology of, 202.

Soap-bubble, on a permanent, 375.

Solanaceae, curious property of the alkalies
of the, 334.

Solly (E.) on the cow tree of South Ame-
rica, 452.

Sowerby (J. De C.) on his new genus,
Tropaeum, of fossil shells, 118.

Stars, shooting, 567.

Stearate of methylene, on, 487.

Stearic aether, on, 487.
Strickland (H. E.) on the geology of
Smyrna, 202 ; on the upper formations
of the new red system, 318.
Strix castanops, characterized, 474.

Strontia, on the hydratesof baryta and, 301.
Structure in the ashes of plants, 13.
Struve, on the siliceous contents of plants,

339.
Suffolk, on the geology of, 106 ; physical
features and geological structure of, 111.
Sulphate of copper, its use for exciting vol-
taic electricity, 145.
Sulphonaphthalic acid, 565.
Sulphuret of carbon, on the preparation of,

221.
Sulphurets of lime, on the, 195.
Sulphuric and sulphurous acids, anhydrous,

on a combination of, 321.
Sylvester (J. J.) on the optical theory of

crystals, 461, 537.
Sylvic acid, examination of, 164.
Syria, on the earthquake in, 204.
Taylor (Mr.) on the solubility of arsenious

acid, 482.
Taylor ( R. C.) on the geology of Holguin

in Cuba, and the mineral region on the

N.E. coast, 17.
Tea-plant, natural history of the country

where found, 390.
Temperature of insects, 189.
Terrestrial magnetic intensity, experiments

on, 58, 254.
Thermo-electric spark, on the, 398.
Thermo-electricity, on, 304.
Thomson (Dr. T.) on the right rhombic

baryto-calcite, 45.
Tides, researches on the, 1 95.
Tobin (Sir J.) on the cast-iron ring money

found on board the wreck of a vessel,

131.
Tovey (J.) on an alleged demonstration

of Fresnel relative to the wave-surface,

524.
Towers ( G. ) on the reception of coloured

fluids in plants, 533.
Toxodon platensis, on the cranium of the,

205.
Tropaeum, a new genus of fossil shells, 1 1 8.
Turner (Prof. E.) on the colouring mat-
ter of the greensand formation, 36.
Turpin on the occurrence of acicular cry-
stals in the tissue of the Aroideae, 444.
Unger on the occurrence of the carbonate

of lime on the leaves of Saxifraga?, 445 ;

on the reception of coloured fluids in

plants, 535.
Valentin on the structure of vegetable

membrane, 437 ; on the dots of spiral

tubes, 441.
Vegetable membrane and fibre, chemical

composition of, 421.
Vegetables, the system of circulation in,

528 ; on the secretory organs of, 530 ;

reception of sap, the secretion and nutri-
tion of, 531.
Viscin, production of, 157.
Voltaic batteries, on the construction of,

76 ; on the employment of iron in the
construction of, 150.

m

INDEX.

Voltaic combinations, observations on, 89.

Voltaic electricity, on tbe phenomena and
laws of action of, 68 ; on the use of sul-
phate of copper for exciting, 145; ex-
planation of the principles upon which
the chemical theory of, is founded, 274.

Voltaic pile, theory of the, 285 ; tensile
effects of, 288 ; dynamic effects of the,
290 ; circumstances which effect the
power of the, 291 ; results arrived at,
293, 294 ; results obtained by Brt*guet's
metallic helix, 298 ; summary of, 299.

Wartmann (JVI.) on the periodical meteors,
261.

Warwickshire, on the upper formations of
the new red system in, 318.

Waterhouse (G. R.) on certain differences
existing between two specimens of Myr-
mecobius, 200.

Watkins ( F.) on thermo-electricity, 304 ;
on the thermo-electric spark, 398.

"Wave-surface, on an alleged demonstration
of Fresnel relative to the, 524 ; in the
theory of double refraction, 417.

Wax, composition of various vegetable, 156.

Wazington (R.) on the action of chromic
acid upon silver, 489.

Well at Beaumoni Green, on a, 215.

Whewell (Rev. W.) on the diurnal inequa-
lity wave on the coasts of Europe, 1 95 ;
researches on the tides : eighth series,
195 ; on his instrument for registering
aerial currents, 474.

Wiegmann (M.) notice of Ehrenberg's
discoveries respecting the Bacillariae,448.

Williams (Rev. D.) on the raised beaches
of Saunton Downend and Baggy Point,
117.

Williamson (W. C.) on the affinity of fossil
scales of fish with those of the recent Sal-
monidas. 300.

Winckler on the products by distillation of
bitter almonds and the leaves of the com-
mon laurel, 160; on the preparation of
pure quassin, 336.

Wind, on the velocity of, 194.

Winds, outlines of a general theory of the,
227, 353 ; notice relative to the theory
of the, 390.

Wires, electro-magnetic, conducting power
of, 1 ; on the conducting powers of, 192.

Worcestershire, on the upper formations of
the new red system in, 318.

Wyatt (J.) on a trap-dyke in the Penrhyn
slate quarries, 103.

Young (J. R.), formula; for the summation
of infinite series, 41 ; on Prof. Wallace's
property of the parabola, 302.

Zinc, chloro-sulphuret of, 560.

Zoological Society, 1 18, 196, 394, 469.

Zoology : — on the first changes in the ova
of the Mammifera, 93 ; hereditary in-
stinctive propensities of animals, 96 ; on
a species of Glaucus, 118; on hollow-
horned Ruminants, 124; Ixalus proba-
ton, 124; Antilope Eurycerus, 125 ;
Antilope Sumatrensis, 1£6 ; Entozoa in
the stomach of the tiger, 1 28 ; structure
of the higher forms of Polypi, 189 ; ana-
tomy of the spermaceti whale, 1 96 ; Phy-
seter macrocephalus, 196 ; a new species
of the genus Perameles, 198 ; differences
existing between two specimens of Myr-
mecobius, 200 ; cranium of the Toxodon
platensis, 205 ; on the Gerboas and Jer-
billas, 394 ; arrangements of the Ru-
minantia, 469; Camelidse, 471; Cer-
vidse, 471; Moschidae, 472; Caprida?,
473 ; Bovidae, 473 ; Strix castanops,
474 ; development of Crustacea, 552.

END OF THE ELEVENTH VOLUME

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