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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. X.

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

JANUARY-JUNE, 1837.

LONDON:

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

SOLD BY LONGMAN, REES, ORME, BROWN, GREEN, AND LONGMAN J CADELL;

BALDWIN AND CRADOCK; SHERWOOD, GILBERT, AND PIPER; SIMI'KIN

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

LONDON : BY THOMAS CLARK, AND ADAM AND

CHARLES BLACK, EDINBURGH; SMITH AND SON,
GLASGOW ; HODGES AND m'aRTHUR, DUB-
LIN J AND G. W. M. REYNOLDS, PARIS.

The Conductors of the London and Edinburgh Philosophical Magazine
have to acknowlege the editorial assistance rendeied them by their friend
Mr. Edward William Brayley. F.L.S., F.G.S., Hon. Mem. S. Afric. Inst.,
Librarian to the London Institution.

CONTENTS OF VOL. X.

NUMBER LVIII.— JANUARY, 1837.

Page

Mr. Charlesworth's Observations on the Crag, and on the
Fallacies involved in the present System of Classification of
Tertiary Deposits 1

Mr. N. S. Heineken's Description of an Anchor found at
Seaton, Devonshire 10

Mr. F. W. Mullins on a Mode of obtaining increased Power
from Magneto-electric Machines ; in reply to the Rev. W.
Ritchie 12

Dr. Boase's Additional Remarks on Mr. Hopkins's *' Re-
searches in Physical Geology" 14

Prof. J. Thomson on the true and extended Interpretation of
Formulae in Spherical Trigonometry ^ 18

Demonstrations of certain Points in Fresnel's Theory of Double
Refraction, deduced from the Investigations of the Undula-
tory Theory which have recently appeared in this Journal 24?

Rev. R. Murphy on a new Theorem in Analysis 28

On the Property of the Parabola demonstrated by Mr. Lubbock
in the Phil. Mag. for August 32

Rev. H. Holditch'a Concise Demonstration of the Property of
the Parabola in the Phil, Mag. for August 35

Rev. P. Keith on the Classification of Vegetables 37

Mr. MacCullagh on the Laws of Crystalline Reflexion 42

Dr. R. J. Kane's Researches in Organic Chemistry, First Series.
— Contributions to the History of Pyroxylic Spirit and of its
derived Combinations 45

Dr. M. Hall on Professor Miiller's Account of the Reflex
Function of the Spinal Marrow 51

Rev. W. Ritchie's Reply to Mr. Rainey's Communication in
the Phil. Mag. for December 1836 57

Rev. W. Ritchie's Remarks on two of the Electric and Mag-
netic Communications in Phil. Mag. for December 1836 . . 60

Proceedings of the Royal Society 62

Geological Society 68

Linnaean Society 71

On the Construction of Oblique Bridges 74?

Observations on the Aurora Borealis 75

Process of making crystallized Sugar from Toddy, or the Juice
of the Cocoa-nut Palm, on the Island of Ceylon 77

Prof. Renwick on the Height of the Rocky Mountains of North
America 78

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 79

a 2

iv CONTENTS.

Page

NUMBER LIX.— FEBRUARY.

Mr. R. Taylor's Notice relative to the Publication of the Sci-
entific Memoirs 81

Mr. G. Bird's Experimental Researches on the Nature and

Properties of Albumen, &c 84?

Mr. A. Connell on the Action of Voltaic Electricity on Iodic

Acid 93

Mr. H. H. Brett on the Solubility of certain Metallic Oxides

and Salts in Muriate and Nitrate of Ammonia 95

Mr. J. Blackwall's Ciiaracters of a new Genus and some unde-

scribed Species of Araneidce 100

Rev. R. Murphy on the Composition of two Rectangular Forces

acting on a Point 105

Rev, P. Keith on the Classification of Vegetables 108

Dr. R. J. Kane's Researches in Organic Chemistry : First
Series. — Contributions to the History of Pyroxylic Spirit and

of its derived Combinations 116

Prof. J. R. Young's Investigation of Formulae for the Summa-
tion of certain Classes of Infinite Series 121

Dr. M. Hall on Prof. Miiller's Account of the Reflex Function

of the Spinal Marrow 124«

The Rev. J. W. MacGauley's Reply to Dr. Ritchie's Remarks 130
Prof. Schoenbein's Further Experiments on a peculiar Voltaic

Condition of Iron ; in a Letter to Mr. Faraday 133

Proceedings of the Geological Society 136

Royal Society 141

On the Reduction of Metals by Electricity 154?

On a simple Method of obtaining Spongy Platinum \5^

On the decolorizing Combinations of Chlorine 155

On the Action of anhydrous Sulphuric Acid on some Metallic

Chlorides 157

Artificial Formation of crystallized Iron Pyrites 158

On the Degree of Cold produced by solid Carbonic Acid. . . . 158

Mellitic Acid 159

Meteorological Observations 159

NUMBER LX.— MARCH.

Messrs. R. C. Taylor and T. G. Clemson's Notice of a Vein of
Bituminous Coal in the Vicinity of Havana, in the Island of
Cuba 161

Mr. C. Fox on Mr. Peter Nicholson's Rule for the Construction
of the Oblique Arch 167

Mr. Brooke on the Crystallographical Identity of certain
Minerals 17O

On the Results of Mr. Fox's Experiments on the Production
of Artificial Crystals by Voltaic Action 1

CONTENTS. ▼

Page
Prof. Schoenbein's Remarks on Faraday's Hypothesis with re-
gard to the Causes of the Neutrahty of Iron in Nitric Acid 172

Note from Professor Faraday on the preceding paper 175

Report by a Committee of the Royal Society (of Edinburgh)

regarding the New Dioptric Light of the Isle of May 176

Mr. L. Thompson's Remarks on Mr. Brett's Experiments on
the Solubility of Metallic Oxides and Salts in Muriate and

Nitrate of Ammonia 178

Mr. C. Riimker on the Solar Eclipse of May 15th, 1836 180

The Rev. W. Ritchie. LL.D. on a simple Mode of exhibiting
Newton's Rings, and a Mode of exhibiting the Fixed Lines

in the Spectrum 183

The Rev. J. B. Reade on a Method of producing Achromatic
Light in Solar and Oxy-hydrogen Microscopes, and on the
Effect of a Current of Air upon the Rays that occasion Heat 184
Dr. M. Hall on Prof. Miiller's Account of the Reflex Function

of the Spinal Marrow {concluded. ) 187

Mr. G. Rainey's Analysis of Dr. Ritchie's Paper in reply to his
last Communication concerning Magnetic Reaction, con-
tained in the Phil. Mag. for January 193

Prof. Forbes on the Results of Experiments made on the

Weight, Height, and Strength of above 800 Individuals .. 197
Mr. L. Horner on an Artificial Substance resembling Shell;
with Sir David Brewster's Account of an Examination of the

same 201

Proceedings of the Royal Society 210

■ Linnaean Society 223

Royal Astronomical Society 227

On the Symmetrizing Power of the Eye, by the Rev. J. G.

Mac Vicar 234-

Starch 235

On the Action of Sulphurous Acid on Steel 235

Analyses and Characters of Minerals, by M. Kudernatsch and

Count Schaftgotsch " 236

Mr. J. De C.Sowerby's Correction of an Error in Mr.Wetherell's

Paper, and Notice of Venus Morrisiif a new Fossil Shell . . 239
Meteorological Observations „ 239

NUMBER LXI.— APRIL.

Mr. J. Young's Account of a new Voltaic Battery, being a
Modification of the Construction recommended by Mr.
Faraday 241

Mr. W. De la Rue on the Effects of a Voltaic Battery charged
with Solution of Sulphate of Copper '. 244

M. J. CI. Marquart's Report of the Progress of Phytochemistry
in the year 1835, in reference to the Physiology of Plants. . 247

Dr. C. T. von Siebold, of Danzig, on a Double- bodied Intes-
tinal Worm, the Syngnmus trachealis 2.53

Vi CONTENTS.

Page
Prof. Forbes on the Muscular Effort required to ascend Planes

of different Inclinations 261

Mr. Heineken on the Aurora Borealis of February 18th, 1837,

as observed at Sidmouth, in Devonshire 265

Dr. Schcenbein's Experimental Researches on a peculiar Action

of Iron upon Solutions of some Metallic Salts 267

Mr. H. M. Noad on the peculiar Voltaic Condition of Iron . . 276
Mr. Brooke on the Intersection of Crystals belonging to dif-
ferent Minerals in a regular and constant manner 278

Mr. J. Taylor on Peroxide of Manganese containing Silver,

from Mexico 279

The Rev. W. Ritchie, LL.D. on the electric Spark and Shock

from a permanent Magnet 280

Mr. F. W. Mullins on the Development and Action of Elec-
tricity in Voltaic Combinations 281

New Books : — Solly on the Human Brain 286

Proceedings of the Zoological Society 287

., Geological Society 306

. Cambridge Philosophical Society 316

at the Meetings of the Royal Institution 317

Fossil Infusoria used for Food 318

Palaeontology: — Organic Forms of certain Minerals 318

Pyrophori of easy preparation 319

Notice of M. Mossotti's Mathematical Researches relative to

the Laws of Molecular Action 320

lodal 321

On the Oxibromides and some other Compounds of Tungsten 322

On Chloroform and Cyanoform 322

Analysis of Silk 323

Fossil Maize 323

Vegetation in a Solution of Arsenic 324?

Indigo 324

On some of the Properties of Per-iodic Acid 325

Mr. J. Watson's Experiment in Electricity 326

Voluntary Sounds of Insects 327

Meteorological Observations 327

NUMBER LXII.— MAY.

Dr. T. Clark on Cyanide of Potassium, an incidental Product
of the Process for making Cast Iron in Blast Furnaces .... 329

Mr. R. H. Brett's Further Experiments on the Solubility of
certain Metallic Oxides and Salts in Muriate and Nitrate of
Ammonia 333

Mr. Kelland on the Laws of Transmission of Light and Heat
in Uncrystallized Media 336

Mr. J. Barton on the Physical Causes of the principal Phaeno-
mena of Heat 342

CONTENTS. VU

Pace

Dr. Boase on the Composition and Origin of Porcelain

Earth 348

Mr. L. Thompson on Antimoniuretted Hydrogen, with some

Remarks on Mr. Marsh's Test for Arsenic 353

Mr. P. Cooper's Notice of a Theory of Molecular Action 355

Mr. G. Bird on the Action of Electricity on Albumen 357

M. Becquerel's Description and Use of an Electro-magnetic

Balance, and of a Battery with invariable Currents 358

Mr. H. F. Talbot's Experiment on the Interference of Light. . 364
Mr. Weaver on the Carboniferous Series of the States of

New York and Pennsylvania 365

Mr. Brooke on the Identity of two Minerals from Vesuvius

named Biotine and Anorthite, and on a new Variety of

Hemitrope Crystal of Quartz 368

Mr. J. T. Graves on the Rev. J. G. Mac Vicar's Experiment on

Vision 370

Prof. J. F. W. Johnstone on the Composition of the right

Rhombic Baryto-Calcite, the Bicalcareo-Carbonate of Baryta

of Dr. Thomson 373

Proceedings of the Royal Society 376

.- Royal Irish Academy 382

Geological Society 388

Prof. Wheatstone on the Thermo-electric Spark, &c 414

On the iEthereal Oil of Wine, by Liebig and Pelouze 417

(Enanthic 7Ether 418

Dr. R. D. Thomson on the Preparation of Boron 419

Experiments on Camphor 420

M. Lassaigne on a Compound of Albumen and Bichloride of

Mercury 420

CEnanthic Acid 422

Meteorological Observations 423

NUMBER LXIII.— JUNE.

Prof. Schoenbein's Experiments on the peculiar Voltaic Con-
dition of Iron as excited by Peroxide of Lead; in a Letter
to Mr. Faraday 425

Prof. Schoenbein's Further Experiments on the peculiar Vol-
taic Condition of Iron as excited by Peroxide of Lead .... 428

Dr. R. J. Kane on the Protochloride and Terchloride of Iodine 430

Dr. T. Andrews on the Thermo-electric Currents developed
between Metals and Fused Salts 433

Mr. Westwood's Descriptions of some new British Species of
Hymenopterous Insects 440

Mr. Alfred Essex on the Art of Painting in Enamel 442

Dr. G. O. Rees on the Hydrate of Magnesia 454

Vill CONTENTS.

Page
Replies by Mr. E. M. Clarke, the Rev. Professor Callan, and
Dr. Ritchie to certain Papers on Subjects of Electricity and
Magneto-electricity inserted in the preceding and present

volumes of the Philosophical Magazine 455

Proceedings of the Linnaean Society 464?

Geological Society 471

— — — Zoological Society 479

■ at the Evening Meetings of the Royal Institution 485

Cambridge Philosophical Society 485

— Royal Irish Academy 487

Mr. T. A. Knight upon the supposed Absorbent Powers of the
Cellular Points, or Spongioles, of the Roots of Trees and

other Plants 488

On the Action of Presence, by M. Pelouze 489

On Catalysis and the Action of Presence, by M. Berzelius . . 490

M. Leveill6 on the Hymenium of Fungi 492

On the Ascent of the Sap 494

Magnetic Observations of the Aurora of February 18th 494

On the Decomposition of Carbonate of Lime by Heat 496

M. Bussy on the Preparation of Iodine 498

M. Bussy on the Preparation of Bromine 499

M. Mulder on the Red and White Oxide of Phosphorus 499

Action of Iodine on the Vegetable Alkalis 50o

Meteorological Observations 503

PLATES.

I. A Plate illustrative of Mr. Brooke's Paper on the Crystallographical
Identity of certain Minerals; and also of M. von Siebold's Paper
on the Sj/ngamus trachealis.

II. A Plate illustrative of the Papers by Mr. J. Young and Mr. Warren
De La Rue on their respective New Voltaic Batteries.

III. A Plate illustrative of Mr. Brooke's Paper on the Identity of two
Minerals from Vesuvius named Biotine and Anorthite, &c.

ERRATA.
P. 165, 1. 26, for cake read coke.
279, 1. 5, /or Bavaria read Baveno.
394, 1. 18, /or sulphurets read sulphates.
417, 1- 21 from the bottom, and p. 418, 1. 11, /or Pelouse read

Pelouze.
419, 1. 19, for " the country," read " this country."
422, 1. 19 from the bottom, /or " as just described, read "as de-
scribed in p. 418."

THE

LONDON AND EDINBURGH
PHILOSOPHICAL MAGAZINE

AND

JOURNAL OF SCIENCE.

[THIRD SERIES.]

JANUARY 1837C

I. Observations on the Crag, and on the Fallacies involved
in the ^present System of Classification of Tertiary Deposits.
By Edward Charlesworth, Esq., F.G.S., S^c.^

1DID not venture to propose a separation of the marine
deposits above the London Clay in Suffolk, until I con-
sidered myself in possession of something more than merely
conjectural evidence to justify my division of these fossiliferous
strata. That the immense accumulation of testaceous reli-
quiae forming the Crag might in some places be seen to be
separated from the subjacent beds of clay by a deposit the
characters of which did not accord with the general aspect of
either of these formations, was a statement involving mere
personal observation, and which could therefore at any time
be readily refuted or confirmed. But that this coralliferous
stratum should be looked upon as holding an intermediate
place not only in geological position, but in age, when consi-
dered in relation to the beds above and beneath it, was sug-
gesting a notion which appeared to me so far admissible, that
its adoption or rejection would entirely depend upon the results
attending continued investigation. Anticipating the nature
of the objections which 1 thought might probably be urged
against my views, I endeavoured, in my first memoirf; to show
that there were strong grounds for believing that the apparent
agreement between the organic remains of the Coralline Crag

* Communicated by the Author.

t See Lond. and Edii^b. Phil. Mug. for August 1835 : vol. vii. p. 81.

Third Series. \^ol. 10. No. 58. J«?z. 1837. B

2 Mr. Charlesworth on the Crag^ and on ascertaining

and the superior beds, depended upon the abrasion or natural
degradation of one deposit during the formation of the other.
I then referred to the large proportion of Red Crag fossils
which M. Deshayes had identified with species now known to
inhabit the German Ocean (4-0 per cent.): consequently, if my
idea of the removal of the fossils from an older to a more recent
bed were disputed altogether, the number common to the two
crag series would at any rate indicate no nearer approxima-
tion of the periods during which these Testacca existed than
that established by M. Deshayes between those of the red crag
and the Mollusca of our present seas. Under these circum-
stances, it was certainly with some degree of surprise that
I found Mr. Lyell opposing the opinion 1 had advanced, upon
no other ground than that of this very occurrence of analogous
species in the two deposits*.

To say nothing of those Sicilian strata, which contain
ninety-five per cent, of existing species, it is palpably evident that
if a per centage of analogous forms, to the amount of thirty or
forty, place in one and the same geological period the races
of organized beings occurring in rocks naturally separated by
superposition and mineral character, by the same line of rea-
soning must the red crag, in common with all the other plio-
cene deposits, be looked upon, geologically speaking, as part
and parcel of the formations now going forward in the adja-
cent seas, although these very deposits have been referred to
a distinct epoch by Mr. Lyell from the very circumstance of
their containing 40 per cent, of existing species. Paradoxical
as it may appear, the facts which in one instance are made
use of to prove the wide interval which has elapsed between the
deposition of certain marine strata, are on another occasion
brought forward to establish diametrically opposite conditions.
Thus a division called older pliocene is made for those beds
which contain so few as 40 per cent, of species common to
that period and the present, while the red and coralline crag
must be identified, — because their fossils indicate just this same
degree of approximation to one another. I apprehend that
this is no other than a fair statement of the case, and that I
have not pushed analogy beyond reasonable limits ; for if we
admit, with Mr. Lyell, that the formations of the present day
constitute one link of the entire series, and originate in the

mtinued operation of those causes which have been in ac-
tivity, at least during the deposition of the supracrt-taceous

)cks, we are surely justified in drawing analogous inferences,
whether we are comparing the present deposits with the newer
members of tlie tertiary series or the individual members con-
stituting the tertiary group with one ^i;^gther.

* Lyell's Geology, 4tli edit., vol. iv. p. 87.

the relative Age of Tertiary Deposita, S

Such then was the condition of the inquiry up to the time
of a small series of shells from Ramsholt being placed by Mr.
Lyell in the hands of M.Deshayes, and the result attending his
examination of these fossils has been appealed to as one which
must necessarily prOve fatal to the views which I entertain
as to the relative antiquity of the coralline crag *. A fellow-
labourer in the field of geological research, presuming that all
other sources of evidence must yield to the deductions arising
from a concho-geological investigation, has been led, perhaps
rather too precipitately, to exclaim, " If such be the fact, there
is an end of the question between my opponent and myself."
I trust, however, that without subjecting myself to the impu-
tation of obstinately adhering to preconceived opinions, I shall
be able to show that this question is not to be decided by
quite so summary a proceeding. A critical examination into
the real merits of the per-centage test, as a general rule for
determining the comparative ages of tertiary deposits, will be
found to exhibit such extensive limits of error in its practical
application, that so far as the present inquiry is concerned, I am
confident that no impartial observer would feel justified in en-
deavouring to form a conclusion, either on one side or the other,
from the evidence which has yet been obtained from this source.

Before I proceed to discuss the value which should be at-
tached to certain numerical calculations, I must briefly digress
for the purpose of offering a few remarks upon the real nature
of the discussion now pending, and its abstract geological
importance.

There are doubtless some to whom it may appear a matter
of little or no moment, whether we speak of these inferior
beds as forming the lower part of the crag formation, so long
as that geological distinction is made, or whether we consider
them altogether as a distinct deposit. Here I would observe,
in passing, that there is no a priori reason whatever why
a distinct deposit should not be found between the beds called
crag and the London clay. In fact, if we adopt Mr. LyelFs
present classification of the British and Continental tertiary
series, such a discovery would seem to be in every respect a
desideratum, for the crag being placed in the pliocene period
and the London clay in the eocene, a dc posit of an inter-
mediate age would lessen the hiatus between these two forma-
tions. Now among some of the important results which have
arisen from the accumulated observations of geologists are
certain general deductions, involving points of a physiological
or general philosophical nature which possess an extreme
degree of interest, apart from any connexion with geology as a

See a paper by Mc^S^WoodwarJ in Lond. and Edinb. Phil. Mag.,
vol. viii. p. 139; ajj^^a^so Mr. Lycll's address to the Geological Society,
Ibid., p. ox?7.

B2

r i)y ivic*
auiL ajsc

4 Mr. Charlesworth oji the Crag, and on ascertaining

distinct science. Such are the changes of climate anterior to the
historic aera, the comparative duration of species, and the wide
geographical range which some extinct organisms enjoyed,
having apparently existed at the same period over an immense
extent of surface. These and numerous other inferences of
a similar kind often depend in a great measure upon the ac-
curacy with which we can refer individual beds or groups of
strata' to particular deposits, and trace these separate forma-
tions in widely remote localities, from observing the occurrence
of certain corresponding phaenomena. Philosophically speak-
ing, it is, perhaps, of most importance in the fossil iferous
rocks to make out the natural subdivisions (if such really
exist) of the two extremes of the series; and in arriving at any
generalizations analogically deduced from our present insight
into the laws of nature, those deposits offer the most legiti-
mate grounds for rational speculation which appear to have
originated during an aera that impinges upon the present.

The most novel feature in the organic remains of the crag,
considering the whole deposit as referrible to one period, is the
occurrence of so many recent mammiferous species in one
bed, and so large a series of extinct corals in the other. Now
if the coralline crag be older than the stratum in which these
mammalian remains are found, we have no longer this asso-
ciation of extinct forms in one class of the animal kingdom
with recent types belonging to a very different order. A geo-
logist desirous of instituting a comparison between these ter-
tiary deposits and those in other parts of Europe, might meet
with the equivalent of one only, assuming the red and coralline
crag to be distinct. It would then become a question of great
importance whether the organic remains included in the two
series ought to be considered collectively or not, in endeavour-
ing to establish an agreement with the fossils of supposed
corresponding strata in distant localities.

Passing to generalizations of a different character, I will
select one which I think illustrates in a particularly forcible
manner the importance of allowing full play to the present
investigation. The occurrence of some extinct mammiferous
quadrupeds in deposits containing exclusively or nearly so
recent Mollusca^ has led Mr.Lyell to attribute a longer dura-
tion of species to the latter. Applying this argument to the
fossils of the crag, we find conditions of another kind ; for the
forms which are most widely removed from existing types
occur among the corals, while the majority of the mammiferous
animals eitlier closely resemble such as are now living, or
can be identified with those which are imbedded in the al-
luvial or lacustrine depdsits above the crag. Hence we might
infer the short duration of the spe^gi|Bfe}' corals when com-
,.... I . :.u .!... ^'Jammalia, and con^tTS^tlv the still shorter

the relative Age of Tertiary Deposits. 5

period assigned to their existence if the comparison be drawn
between them and MoUusca. In this way erroneous inferences
with regard to the comparative duration of species, and other de-
ductions of an equally important nature, might originate 50/^/^
in an improper identification of the crag beds with one another.
I have made use of the above example as a means of showing
how desirable it is that there should, if possible, be a right
understanding as to the age of the coralline crag: but at the
same time 1 would observe that Mr. Lyeli's line of reasoning
is one which should be applied with the utmost caution ; for
though it may be quite true that the remains of the mammoth
have been found, as at Northcliff in Yorkshire, in conjunction
with recent species of Testacea^ yet before we can with justice
found any argument upon the fact of their occurrence in the
same deposit, it is absolutely requisite to show that association
is a tolerably conclusive proof of contemporaneous existence :
and having settled this point, (which is often no very easy mat-
ter, as will be seen in another part of this paper,) we must next
inquire whether there be evidence o^ anterior coexistence du-
ring periods of equal duration. The fossil elephant of York-
shire is found in the red crag, one of the older pliocene de-
posits ; but the recent species of MoUusca with which in one
case it was associated are not to be traced back to a period of
corresponding antiquity. The duration which we are war-
ranted in assigninor to these latter is the time which has

...
elapsed since the formation of the Yorkshire deposit, while

we can date the existence of the elephant from the deposition
of the red crag up to the period of its subsequent occurrence
in the above-mentioned locality.

So far then as the progress of geology is concerned, I think
ample reasons exist for prosecuting an inquiry into the rela-
tive ages of these tertiary beds; but the attainment of that ob-
ject through the medium of numerical calculations involves
the application of principles, the adaptation of which to the prac-
tical purposes of the geologist is an operation complicated in
its nature, and which may also be often fallacious in its results.

Mr. Lyeli's views upon this subject are so well known and
have been so generally received, that without entering upon
any detail respecting them, I may at once proceed to discuss
the considerations which have led me to distrust the value
the per-centage test in those instances where we require some
thing more than a general approximation towards accurate
conclusions*.

* Some of the following facts and observations were drawn up as a con-
tinuation of a paper on this subject which appeared in the Supplement to
the Phil. Mag. for June 1836. The delay in the publication has arisen
from my wisiiing to lay them before the late^j^ting of the British Associa-
tion at Brifatol.

6 Mr. Charlesworth on the Cragy and on ascertaining

When Professor Agassiz was on a late visit to this country,
I was particidarly anxious that that distinguished naturalist
should have an opportunity of examining the ichthyological re-
mains of the crag. With this view I endeavoured to obtain as
extensive a series of these fossils as possible, and in the course
of the summer of 1835 I collected several thousand bones, in-
cluding vertebrae, teeth, and portions of palates, &c. A se-
lection from these was submitted to the inspection of M. Agassiz
just before he quitted England, and the result of his examina-
tion was, that among them he could detect no recent species,
and that there were some belonging even to genera extremely
remote from any with which he was acquainted. This was a
result which 1 was not prepared to anticipate, as the crag had
been classed by M. Deshayes among the pliocene deposits, in
consequence of the large proportion of its shells which he had
identified with recent species. On a subsequent occasion, how-
ever, when M. Agassiz had an opportunity of seeing my entire
collection of crag fossils, after expressing great delight and
astonishment at the novel structures exhibited by the corals, he
mentioned to me his opinion that all the Testacea which he
had seen from that formation were extinct. I cannot ven-
ture to say what amount of reliance should in this instance
be placed on the opinion of Professor Agassiz, but certainly
his zoological attainments are by no means confined to that
particular department of scientific inquiry in which he has
deservedly gained such extensive reputation. The obser-
vation thus casually made to me by him was shortly after-
wards most unexpectedly confirmed by Dr. Beck of Copen-
hagen, who appears to have enjoyed very extensive facilities
for the study of recent and fossil conchology. Dr. Beck com-
municated to me his opinion of the incorrectness of M. Des-
hayes' calculation before he had examined my collection, the
inspection of which did not occasion any alteration in his views,
as may be seen by Mr.Lyell's anniversary address*.

If we now turn to our own country we shall find a most re-
markable discordance upon this subject in the opinions of
British naturalists, although the balance is certainly not in fa-
vour of M. Deshayes. Mr. George B. Sowerby informs me that
he has had many opportunities of comparing the crag shells
ith recent specimens, and that he has only found two or three
Is which may perhaps be identified with living species.

^Vofessor Phillips's Guide to Geology, we find him

piftcmg'tlie crag in the miocene division, probably estimating
the proportion of extinct species at about seventy or eighty
per cent. I \\qq{\ not here dwell upon Professor Phillips's ge-
neral accuracy of observation and long familiar acquaintance
* bee ]>ond. and Edinb. Phil. Mag., vol. viii. p. 327.

the relative Age of Tertiai'y Deposits, 7

with organic remains. I may however mention that there is
a large series of crag shells in the museum at York, from the
examination of which I believe his opinion has been formed.
In justice to M. Deshayes, I must now observe that there are
several individuals to whose judgement I should be disposed to
pay considerable deference, who think that in giving 40 per
cent, he has considerably underrated the proportion of recent
species, and that more than half, or perhaps three fourths of
the crag shells can undoubtedly be identified with species now
inhabiting the German Ocean.

The Rev. Dr. Fleming, in a letter to Dr. Mitchell, F.G.S., of
London, in alluding to this subject, observes, *' Many of the crag
species are deep-water species, but I would fearlessly say they
are of British origin, and I make the remark, having been an
observer and collector of British shells for more than a quarter
of a century.'*

In the annual address delivered by the President to the
Fellows of the Geological Society, Mr. Lyell particularly ad-
verts to the discordance of opinion between two such eminent
naturalists as Dr. Beck and M. Deshayes, and suggests that it
may probably be attributed to their difference of opinion as to
the amount of variation necessary to constitute a distinct spe-
cies. Thus, for instance. Dr. Beck would look upon those six
or eight forms which M. Deshayes includes under the name of
LiUcina divaricata as six or eight distinct speciesof the genus Lu-
cina, while M. Deshayes would consider them as varieties only.
Now this explanation is only admissible upon the assumption
that M. Deshayes allows the existence of as much difference be-
tween the craoj fossils and what he now regards as their living
analogues as there is between the six or eight varieties of the
Lucina divaricata. This is an important consideration; for if
M. Deshayes should assert the identification to be complete
between the crag fossils and living shells, it is evident that the ex-
planation offered affords no solution whatever of the difficulty.

From these facts the following inference may, I think, be
fairly drawn : that if a series of tertiary fossils be placed before
the most eminent conchologists in different countries, for the
purpose of ascertaining from the pef-centage of extinct species
what position in a geological series the formation should hold
from which these fossils have been obtained, that position
might be decided to be, eocene in Denmark, Tw/ocd^w^ in England,
and pliocene in France ; and had we fifty intermediate grada-
tions it is very possible that no two conchologists would refer
the deposit in question to the same position.

Greatly as the discordance of these results is to be lamented,
as retarding the progress of geology, it must mainly be attri-
buted to the present imperfect condition of conchological sci-

A

6 Mr. Charlesworth on the Crag, and on ascertaining

ence, and not be supposed to invalidate the general course of
induction pursued by Mr. Lyell. Nevertheless it must be ad-
mitted that the practical application of the principle advocated
by this eminent geologist in the classification of the supracre-
taceous rocks will be extremely limited in operation ; for even
if we suppose that conchologists universally admit the sound-
ness of the principles upon which the present system of chro-
nological arrangement is founded, they cannot equally make
use of it as a means of obtaining numerical relations of affinity,
since the characters thought by one to constitute a distinction
of species are by another looked upon as mere modifications
of form.

Now, if we entirely throw aside all reference to a per-cent'
age of species, and could substitute in its place a scale of de-
grees,— still taking the existing forms as a standard to which
the fossil ones are to be referred, but determining the amount
of approximation by the totality of the characters which each
series exhibits, — we might then, perhaps, justly anticipate
an agreement in the conclusions arrived at by different con-
chologists as to the relative age which should be assigned to
any one fossiliferous deposit of the tertiary group ; provided,
of course, that there be no difference in their respective quali-
fications for conducting the necessary examination*.

Although Dr. Beck asserts that the Testacea of the crag
have no existing analogues, thereby necessarily placing that
formation in the eocene division of Mr. Lyell, yet as he ad-
mits a very considerable degree of resemblance in many of
these fossils to species now living in the German Ocean, I ap-
prehend that from that circumstance he would refer this de-
posit to a much more recent geological aera than the London
clay. If I am right in this conjecture, it follows as a neces-
sary consequence that there are two modes by which we esti-
mate the degrees of affinity between fossils of separate de-
posits, or between fossil and recent species, one being the
per-centage test, and the other that which must of necessity be
employed by Dr. Beck were he to infer the greater antiquity
of the organic remains of the London clay when compared with
those of the crag.

Now it can be clearly proved that one of these modes is
sometimes fallacious, as there are tertiary deposits to which
if both tests be applied results completely at variance with

ich other will be evolved. Thus many of the forms occur-

tng in the coralline crag are so unlike recent types, that if our

estima^of its comparative age were taken from the totality of

* I am proceeding here upon the supposition that there is an uniform
approximation to existing species, shown by the fossils of different deposits,
correspondin^to their respective antiquity.

igio th

the relative Age of Tertiary Deposits. 9

the characters which its fossils, considered collectively, present,
it would appear much older than the superjacent tertiary
beds, but if the numerical test be made use of, the apparent
age of both these deposits would be equal. Some remarks by
Professor Phillips which have appeared in the Encyclopcedia
Metropolitana, and which were probably written bef()re 1 had
described the conditions under which the organic remains of
the crag are deposited, bear very strongly upon the above
statement. The passage is as follows ; " Upon comparing
them [that is, the crag fossils,] with recent kinds, we are pre-
sented with very curious and striking results. There are se-
veral of the crag shells so exceedingly similar to recent shells
of the German Ocean that it is impossible to distinguish them.
Turbo littoreus retains its colour, many others are with dif-
ficulty separated by minute discrimination ; but some, as the
corals of Orford^ Pecten Princeps, Terebratula iJalei, and
others^ are evidently unlike anything now existing in the Ger-
man Ocean, and indeed not now to be paralleled in any part of
the world" — Encyc. Metrop., Geology, p. 674.

Now the Corals, Pecten and Terebratida, spoken of by Pro-
fessor Phillips as so utterly unlike anything now existing, are
fossils of the lower or coralline crag. The Turbo littoreus re-
taining even its colour, so far as my own experience has gone,
occurs only in that bed where we meet with existing species
of Mammifera, and the more recent origin of which I have
from the first endeavoured to establish.

From what 1 have advanced it will be seen that I am dis-
posed to regard the source of error now under consideration
as involved in the application of the per-centage test, and if
the history of the crag be ever thoroughly worked out,
I think this view will be confirmed. The fallacy probably
consists in supposing that by number we can obtain a true
expression of relations of affinity, when being totally ignorant
of the characters which constitute species, we have really no-
thing upon which to found our numerical calculations.

I pass on from the consideration of this rather intricate
question to another stage of the inquiry; and here for the sake
of argument I must assume that there is a general agreement
among conchologists as to the characters upon which specific
distinctions are founded, and also that the true method of ob-
taining relations of affinity is the one which has been adopted
by Mr. Lyell and M. Deshayes.

[To be continued.]

Third Series. Vol.10. No. 58. Jan, 1837.

[ 10 ]

II. Description of an Anchor found at Seaton, Devonshire.
By Mr, N. S. Heineken.

To the Editors of the Philosophical Magazine and Journal,

Gentle iviEN,

THHE anchor from which the accompanying drawings were
*■ taken, was found at Seaton, Devon, on the 25th of August
1836, nearly opposite to an opening on the coast called the
Chan, and at a distance of about 500 fathoms from the shore.
At this spot an obstacle had always occasioned damage to the
seins of the fishermen, although for a considerable distance
around this place the bottom was perfectly plain : many
attempts had been made to ascertain the nature of the hin-
derance to fishing ; but in vain until the time above stated,
when ropes having been attached to the subject of this com-
munication, it was, by the efforts of thirty or forty persons
drawn ashore, very much, as may be supposed, to their amaze-
ment. I am told by my informant that the depth of the sea
where it was found is about 15 fathoms, and that the oldest
inhabitant does not remember that vessels have anchored
within a quarter of a mile from the spot. From the peculiarity
of its form the anchor would appear to be either of consider-
able antiquity, or of foreign make. The naval men who have
inspected it, say, that the shank is from 16 to 18 inches longer
in proportion to the arms than in anchors of the present time,
and the shank also appears to have been square.

It is completely encrusted by a thick covering of sand,
nearly approaching in hardness to sandstone, in which are
imbedded rounded beach pebbles, shells of various kinds,
Serpularia:, Balani, &c.

Description of the Figures.
Fig. 1, is a front view of the anchor, showing at o, Z>, and d^
masses of hard marl, by which it was attached to the ground.

Fig. 2, is a view of the other side, taken rather obhquely, in
order to show the form of the fluke at c.
The dimensions are as follows :
Fig. 1, length of shank from a to h, 4 feet 6 inches.
Distance between the points of the flukes r, d, 2 feet 6
inches.

Thickness of marl at a 7i inches.

Diameter ditto 8 inches.

Jhickness of marl at b 1{ inches.

imeter ditto 7 inches,

b across fluke at c 8 inches.

.Description of an Anchor found at Seaton, Devonshire. 1 1

Width across fluke at </, 7 inches.

Dimensions at e, 2^ inches by 2^ inches.

Ditto aty; 5 inches by 5 inches.

Weight of the whole from 150 to 200 lbs.

If the date of the anchor, from its unusual make, could be
nearly ascertained, it would probably be interesting as indica-
ting the period required for the formation of the incrustation
(puddingstone?) around it in the peculiar situation in which
it was found.

Fig. 1,

Fig. 2.

It may be remarked, that Leland observes that forinerly
Seaton was a place of considerable commercial importance,
though in his time it was a mere fishing-town. It has also
been stated that it had once three harbours. Some anti-
quaries have supposed it to have been the Moridunum of
Antoninus, and in 937 it was the landing-place of the Danish
princes. Now, whether the aforesaid anchor belonged to the
Romans, or the Danes, or is of a more modern date, I leav
to antiquaries to determine from its make, or geologists
its coating, I have done my endeavour to introduce i
curiosity to their notice ; and if coveted, it may, I doubt not$

12 Mr. Mull ins 07t MagJieto-electrical Mac/u?ies,

adorn their museums, by proper application to its present
owner, W. Champ, a fisherman residing at Seaton.

The sketches, 1 may observe, were taken with the camera
ucida, and are therefore, I trust, tolerably faithful.
With respect, I am, yours, &c.

Sidmouth, Nov. 8, 1836. N. S. Heineken.

II L 0?i a Mode of obtaining increased Power from Magneto^
elecb'ic Machijies ; i?i Reply to the Rev. W. Ritchie, LL.D,
By Fred. W. Mullins, Esq., M.P., F.S.S.,M.R.L, ^c*

I

DID not receive the September and October Numbers of
the Lond. and Edinb. Philosophical Magazine, till the
commencement of the present month (November), and in con-
sequence was not previously aware that Dr. Ritchie had made
any observations in relation to my remarks on magneto-elec-
tric machines in page 120 of the August Number. I now hasten
to correct some misapprehensions which it appears that gen-
tleman has fallen into with respect to my statements in the
paper alluded to.

Dr. Ritchie seems to think that I approve of bar magnets for
magneto-electric machines in preference to horseshoe ones : in
this respect he greatly mistakes me ; for I distinctly stated that it
was before trial I believed the former to be superior to the
latter; but that " ^^r trial" it appeared to me that the
power oiall such instruments was very imperfectly developed ;
which impression led to the inquiry and subsequent discovery
already mentioned : so far from dissenting from Dr. Ritchie's
opinion as to bar magnets, I fully concur with him in be-
lieving that of two bars of equal size tempered to the same
colour, and magnetized equally, one of which is divided into
two equal portions, and the other bent into the horseshoe
form, the latter will exhibit the greater power: so far we
agree ; but if Dr. Ritchie means to assert that the power of
the latter will exceed that of the former, after the addition of
the magnetized arcs, then he must permit me to say, that I
consider him to be decidedly in error, and feel myself, after
further experiments, fully justified in adhering to my former
opinion of the great superiority of bar magnets with magnetic
arcs for magneto-electric instruments, I quite agree with
Dr. Ritchie, that " facts are stubborn things to get rid of"
oubtedly they are much to be preferred to arguments

ounded on the imperfectly developed principles of a science

* Communicated by the Autlior.

in reply to the Rev. Prof. Ritchie. 13

•as yet in its infancy; looking to facts therefore, I hope before
long to have an opportunity of convincing Dr. Ritchie of the
correctness of my results as already stated. I cannot well
collect from his details of the second experiment, that Dr.
Ritchie magnetized the connecting arc as well as the bars : for
he says, " cut a bar into three portions ; bend one into an arc,
and magnetize the two parts." If he left, as I assume, the third
part, or the arc, unmagnetized, it will be quite apparent that the
unmagnetic arc will not give the power described by me:
hence his error. The arc and the bars should be magnetized
to saturation, and applied as I have before stated, namely, one
to the opposing poles of the front bars, the other to those of
the hack\ for if placed upon the intervening bars while the
first-named are unconnected^ the effect is not nearly so great.

Dr. Ritchie again mistakes me, when he understands me
to assume, that connecting- pieces less than the dimensions
given, would produce the same increase of power; my re-
marks were made in relation to the size of the arcs described,
as compared with larger ones, and went to show that there was
a limit to the increase of power, in as much as augmented power
did not accompany enlargement of the arcs, and this is the
fact; but it does not at all follow, that because this is the case,
smaller arcs than those described would prove as efficacious ;
for it is easy to conceive that the arcs should contain a certain
amount of aggregated particles magnetically combined with
the electric element, in order to produce the maximum in-
crease of power in the bars ; but that beyond that amount no
increase of the particles could augment the power obtained,
without a proportional augmentation of the bars, or more
strictly of the magneto-electrized particles of the bars.

I am quite free to acknowledge that I did not express my-
self upon this point in terms as precise as I could wish, but a
little consideration would, lam certain, have shown Dr. Ritchie
that I merely meant to signify that sis^e beyond a certain limit
previously defined, did not augment the fower jptoduced.

As I mean to write more in detail upon these matters as
soon as I shall have obtained the results of a course of ex-
periments in which I have been for some time engaged, I
will not go further into this interesting subject at present.

Beaufort-House, Nov. 4, 1836. Fred. W. Mullins.

[ 1* ]

IV. Additional Remarks on Mr. Hopkins^s " Researches in
Physical Geology,'' By Henry S. Boase, M.D., cJ-c, Se^
cretary to the Royal Geological Society of Cornwall,*

TT was with great pleasure that I read Mr. Hopkins's reply
-^ to my former remarks, because a discussion conducted in
a proper spirit cannot fail to elicit truth, and may be the means
of stimulating geologists to investigate more carefully the im-
portant question under consideration.

The point at issue between us is, as Mr. Hopkins has justly
remarked, "whether the jointed structure of disturbed masses
has been in great measure superinduced previously or subse-
quently to their elevation." Two other topics have been dwelt
on in his reply,— the nature of the elevatory force, and the
origin of veins, — both very interesting, but not, I conceive, so
easily determined by observation^ as the question more imme-
diately under discussion.

Mr. Hopkins asserts, " that it is totally inadmissible to
assume the earth's crust to have become jointed, before the
action of the dislocating force upon it." I, on the other hand,
contend that solid rocks not only existed previously to their
having experienced elevatory movements, but also that such
rocks must necessarily have had 2i jointed structure. This is,
1 think, a fair and plain statement of the case sub judice, di-
vested of all its collateral intricacies: now then for the evi-
dence.

As regards the structure of rocks, how does the matter
stand at the present day? If we examine any formation from
the oldest non-fossiliferous strata to the newest of the tertiary
deposits, or indeed to the recent sandstones of the modern or
diluvial epoch, the evidence is invariably the same : all de-
monstrate that solid rocks, whether they have or have not
been subject to movements, possess a concretional structure,
being intersected by lines or joints which divide them into de-
terminate masses. And not only so, but granitic and trap-
pean rocks, and even lavas, all, when solidified, are similarly
circumstanced. Nor can this excite any wonder, since a con-
trary state of things would not be in accordance with the laws
of nature, — it being a fundamental maxim in physics, that the
particles of solids are united together by attraction of cohe-
sion, which has a tendency to arrange bodies in definite forms.
If we did not know the fact, would it not have been a legiti-
mate inference that solid mineral masses might be found to
a concretional structure? But in as much as all
solid rocks, whether igneous or aqueous, disturbed or

* Communicated by the Author.

Dr. Boase in reply to Mr. Hopkins. 15

in their original position, in mass or insulated between loose
earthy beds, — in as much, I say, as all these exhibit joints or
lines of structure, I think that I am justified in regarding
this condition as a species of crystallization, — the inseparable
consequence of the particles of an originally unconsolidated
mass liaving been completely subjected to the operation of
cohesive attraction.

If Mr. Hopkins's hypothesis requires it to be otherwise, it
is incumbent on him to adduce facts in support of his opinion.
Perhaps, he will not dispute this position, but content himself
with maintaining that the rocks, when elevated, were not in a
solid state. I shall, however, have no difficulty in establish-
ing the contrary ; for there is ample evidence of rocks, before
dislocation and elevation, having been solidified.

But, says Mr. Hopkins, "in my investigation it is unneces-
sary to suppose any but the lowest degree of solidification in
the elevated mass ; and therefore it is^ manifestly quite inad-
missible to assume that it could not be dislocated by an eleva-
tory force before its jointed structure had become sufficiently
developed to determine the directions of dislocation." I do
not assume that an unconsolidated mass cannot have been
elevated or depressed ; because it is evident, that recent se-
dimentary deposits must be acted on, according to the move-
ments of the older solid rocks on which they repose ; but I do
assert that rocks over extensive regions in every part of the
globe, (and only one instance would suffice for the argument,)
when thus acted on, were not in the lowest, nor in any inter-
mediate degree of the process of induration, but were per-
fectly consolidated.

For instance, various series of rocks, including those of
more than one epoch, have accumulated, during the lapse of
ages, from the comminuted debris, angular and water-worn
fragments of older rocks, in the hollows of which they have
been deposited; these derivative rocks now exhibit faults,
veins, and other indications which Mr. Hopkins ascribes to
elevatory movements. Now it is of no consequence whether
these upper derivative rocks were solid or not ; but it is evi-
dent that the parent fundamental rocks must have been per-
fectly solid or they could not have furnished the pebbles, which
very commonly consist of quartzose and other siliceous sub-
stances, not only belonging to older sedimentary formations
but also to igneous rocks which cannot be supposed to have
been reduced to a state of detritus by aqueous action until
they were actually so/zW. It may also be remarked, that it i
generally admitted that movements, such as have taken pi
in former days, are now and will be hereafter in operation:

1 6 Dr. Boase's Additional Remarlcs on

there can be no doubt then that all future dislocations must
aflect a basis of solid rocks possessing lines of structure, and
therefore would be subject to the modifying circumstances
which Mr. Hopkins is desirous of evading.

In opposition to this statement, can Mr. Hopkins adduce
any evidence in support of his conjecture, that various degrees
of solidification existed in all the rocks subjected to elevatory
movements? If not, the convenience alone of his hypothesis
ought not to be admitted as a sufficient argument ; and my
deduction from facts cannot be considered as satisfactorily
answered by treating it as ^' a priori reasoning founded on what
we are alto^jether ignorant of."

In order to illustrate the subject more fully, let us direct
our attention to the principal movements which Cornwall is
supposed to have undergone. These appear to be referrible
to four periods, marked by —

1st. The protrusion of the granite through the stratified
rocks, tilting them up at various angles, and injecting granite
in the form of veins into the adjacent fissures.

2nd. The formation of porphyritic dykes or elvan-courses
which traverse both the granite and the slate.

3rd. The production of metalliferous veins, intersecting the
granite, slate, and elvans ; and,

41 h. The introduction of another system of veins, traversing
all the preceding formations, locally termed cross-courses.

1. What was the condition of the stratified rocks, when
the first and most remote movement occurred ? Could it
have been at the lowest degree of solidification, or indeed, at
any degree short of absolute solidity? I think not. 1st, Be-
cause, admitting that process to have been " the gradual work
of lengthened periods of time," we have a very sufficient limit
in the countless ages which must have elapsed between the
deposition of the non-fossiliferous strata of Cornwall and
the formation of the carboniferous or the saliferous group,
whichever may be determined to mark the period when the
granite was protruded. 2ndly, Because the nature of the de-
tritus derived from the older strata, and contained in the con-
glomerates formed before the elevation of the granite, indicate
that the parent rocks must have been in a solid state. And
lastly, because the sharp angular portions of slate, included
within the granite veins, demonstrate that they could not have
been forcibly detached from rocks only partially solid. Thus
^then we see that even iii limine Mr. Hopkins has great diffi-

Ities to contend with, in refusing to admit the perfect solidity
^oftlic inferior disturbed strata; and these must necessarily
be ii^^ased at each successive step. But before advancing

iQ^aseu

Mr. Hopkins's " Researches in Physical Geology'^ 17

we must allow the melted granite to cool, and the supposed
belt of altered slate to assume its new or superinduced lines
of structure. This being accomplished, then follows the —

2nd. Movement, as denoted by the formation of fissures, in
which the dykes of elvan now occur, and which run con-
tinuously through both granite and slate. We have seen
that the latter rock was already solid, and there can be little
doubt that the granite was also in a similar state ; for very
highly inclined fissures, twenty to fifty feet in width, could
scarcely have been maintained in an ignited mass, possessed
of any degree of viscidity ; because, if in any state short of
solidity, the incumbent pressure would cause the mobile
mass to sink into and obliterate such fissures.

3. The movement which gave origin to the metalliferous
veins seems also to have operated on solid rocks, since they
cut through granite, slate, and elvan which must have been
previously in a state to furnish considerable quantities of an-
gular portions of all these rocks with which the veins abound :
independently of the fact that this movement was subsequent
to former dislocations which, it has been shown, occurred in
rocks already solidified.

4. The movement, indicated by the cross-courses also
containing detached portions of rocks, must likewise have
been effected in a solid mass. It is superfluous to make any
further remark on this head ; but I will here observe, that
Mr. Hopkins has fallen into an error in stating that cross-
courses are universally recognised to be of irregular width, as
compared with the " bearing " veins. The fact is, that both
systems are exceedingly irregular in this respect ; but if any
rule obtains, it is the reverse of Mr. Hopkins's statement.
Some importance appears to have been attached to this differ-
ence in width, but I cannot detect the nature of its bearing-

From these facts* it appears, that in Cornwall the rocks

* In discussing this subject I have endeavoured to keep the argument
as simple as possible, and therefore have not dwelt on the phaenomena of
veins. But as a specimen how the difficulty of Mr. Hopkins's position in-
creases when applied to some only of the details, I may observe that two
parallel systemsof veins frequently occur inclined towards, and intersecting
each other, at great angles ; whilst they aie both traversed by a third
system or cross-courses. All these veins are parallel to, and partially
identical with three systems of joints or lines of structure, dividing the mass
into concretions which are generally of a rhomboidal form. Here, then,
(without complicating the matter still further with joints and veins, which
in Cornwall, and probably in other countries, traverse the quadrilateral
concretions diagonally,) we have systems of veins crossing each other at
acute angles, a condition which Mr. Hopkins has stated cannot have been
produced by the elevatory or other extraneous forces, as these, he says,
"could only tend to produce systems of fissures crossing each other at
right angles."
' Third Series. Vol. 10. No. 58. Jaji. 1837. D

i

A

18 Prof. J. Thomson on the true and extended

were solid previously to their elevatory movements; and that
they also possessed lines of structure is more than probable,
since the fragments contained in the granite veins, in the el-
vans, and in the two systems of mineral veins, exhibit the
same concretional forms as those into which the corresponding
rocks are now divided by weathering or mechanical action.

Thus I have endeavoured to substantiate my former state-
ment, that the elevatory force could not have acted on a solid
mass without the interference of lines of structure ; a circum-
stance which would produce, according to Mr. Hopkins, such
considerable modifications in the resulting phsenomena, that
"to a mass thus constituted these [his physical] investigations
must not be considered as generally applicable."

When I commenced this reply, it was my intention to have
offered a few remarks on Mr. Hopkins's lengthened comments
on the hypothesis which I have advocated concerning the
origin of mineral veins in primary districts; but as it is im-
material, in the present case, whether the veins, granite, and
slate are or are not all contemporaneous, I think it best not
to have our attention diverted from the point at issue, which
must be determined by facts, and not by the gratuitous postu-
lata of either hypothesis.

I cannot, however, conclude without again acknowledg-
ing the great obligation geologists are under to Mr. Hopkins
for his interesting investigations; and, though differing from
him on some points, I am not insensible to the great advantages
which must accrue to geology in controlling wild specula-
tions by the application of the rigid laws of physical science.

Penzance, Nov. 8, 1836.

V. On the true and extended Interpretation of Formultje in
Spherical Trigonometry, By James Thomson, LL.D.^

Professor of Mathematics in the University of Glasgow.*

l.Xl^HILE the rules and theorems given in the modern
^^ books on trigonometry, in reference to spherical tri-
angles, are sufficient for all practical purposes, yet there are
some peculiarities and some curious relations of such triangles,
which have either been overlooked in all the works with which
I am acquainted, or have been merely glanced at in casual or
passing remarks ; and hence, as may be expected, some parts
of the theory are still imperfectly developed. I shall proceedf

* Communicated by the Author.

t The formula; quoted in this paper will be found in my Elements of
Plane and Spherical Trigonometry, and in most of the modern treatises on

the Subject.

Interpretation of Formulce in Spherical Trigonometry. 19

to give some instances of this kind, and shall commence with
the formula

» cosfl —cos h cose

cos A. — _ -. a

sin 0 sm c
which enables us to solve the problem in which the three sides
are given, to find the angles. Now, since, if Q be any arc or
angle, cos Q = cos (2 tt — Q), it is plain, that if A' denote
one value of the angle A, there will be another value 2 tt — A',
unless it can be shown that this value is excluded for some
reason not indicated by the foregoing formula. Let the
former of these be less than two right angles ; then, if the
latter, which we may denote by A'', be admissible, it will be
greater than two right angles *. In like manner the corre-
sponding formulae would give two expressions, B' and B"
(= Stt -B'), for B; and two, C'and C"(= 2 7r-C0, for C.
Now the first of these. A', B', C, regarded ^s being each less
than two right angles, are those which are universally, and,
in a practical point of view, correctly employed. On consi-
deration, however, we shall find that the latter values are just
as admissible as the former. When a great circle is described
through two points on the surface of a sphere which are not
the extremities of a diameter, the points may be regarded as
hen\g joined by either of the arcs into which they divide the
circle : it is usual, however, to consider the smaller arc as the
one which joins them. Now, if we take on a spherical surface
three points which are not on the same great circle, and join
them in the way last mentioned, by three arcs, a, b, c, we shall
obviously divide the entire surface into two parts, each bounded
by three arcs of three great circles, and therefore each of them
a spherical triangle. The smaller of these is that which is
usually alone considered, and its angles are A', B', C\ The
greater has for angles A", B'', C; and, having a, b, c as sides,
it answers the conditions of the problem just as well as the
smaller triangle. The angles of the greater triangle are evi-
dently each greater than two right angles.

* It is scarcely necessary to state, that there is no impropriety in re-
garding an angle as greater than two right angles. If we suppose one
radius of a circle to be fixed, and another to revolve from a state of coin-
cidence with it, the motion of the latter will make continual additions to
the quantity of angular space described ; and the angle made by the lines,
commencing from nothing, may be regarded as increasing so as to obtain
any magnitude we please. If the line revolve in one direction, the angle
may be regarded as positive ; if in the other, negative. It is plain also, that
if any angle Q has been described, the relative positions of the lines will
be the same again after the description, once or oftener, of four right
angles in either direction; or, as it may be expressed, the relative positions
of the lines will be the same, when the angle which they make is Q, as
when it Q + 2 nx, n being a whole number.

D2

20 Prof. J. Thomson on the true and extended

2. What has been thus established aflPords an explanation
of the double sign + , before the expressions for the sine and
cosine of half any angle of a spherical triangle. Thus, in the
formula

si„.A=+ /^i"(^-^)sin(.-c)
^ ~~ t^J sm 0 sin c

if we denote the value of ^ A corresponding to the sign +,
by ^ A', we shall have the other, corresponding to — , equa
to — ^ A'; whence the values of A are A' and —A'; or, by
adding 2 tt to the latter, according to the preceding note, the
values will be A'and2 7r— A'. We see, therefore, that the
positive value of sin ^ A gives the value of | A in the less of
the two triangles bounded by a, /;, r; and the negative value
that of I A in the greater*.

3. In like manner, in the formula

^ —V sm o sm c

the positive and negative values will give respectively ^ A
equal to | A' and tt — ^ A'; and consequently A equal X,o A!
and 2 tt — A', as before: and, in a similar manner, we may ex-
plain the double sign in the formulae

'sin (5—-^) sin(5~c)

tanJA=±Y/-

sin s sin {s—a)

, . . 2 \^ s\n s sm I s—a) sm is— b) ^m is— c)

and sin A = H ^^^ — ^, — ^ ^^ -'

— sin 0 sin c

4. By considering in a similar manner any of the formulae
which determine the sides bv means of the angles, we shall
arrive at other results which do not seem to have been hitherto
observed. Thus, from the formula

cos A + cos B cos C

cos a = ; :^r—. — ^ ,

sm B sin C

and the corresponding ones for cos h and cos c, we see that
when the three angles are given, each of the sides has two
values of the forms a' and ^v—a, h' and 2 7r — 6', c and
2^— c'. The values a\b\c\ each less than a semicircle,

* The same conclusions might be derived from the formula for sin ^ A,
taken, not with both its signs, but with either. For, since sin Q =: sin (^ — Q),
we should have for the value of \ A, corresponding to the positive sign,
either ^ A' or -jr — ^ A' ; and consequently A equal to A' or 2 Tr—PJy as
'ore; while the negative value will give — ^A' and — cr-f ^A'j by doubling
[ch, and adding to each 2 t, we get 2 tt— A' and A', as before. The
also be done by means of the formula for cos \ A.

Interpretation of For mules in Spherical Trigonometry, 21

are those which alone are recognised by writers on trigo-
nometry. With regard to the others, they are evidently
the remaining arcs of the great circles of which a\ b\ c
are parts, and they are therefore each greater than a semi-
circle. In fact, if the triangles be described, whose sides are
a', h\ c\ and whose angular points are A, B, C, so that A
and B are joined by c\ A and C by U, and B and C by a' ;
then 2'K—c is the other arc joining A and B; 2^ — 8' the
other arc joining A and C, &c. These larger arcs, being the
continuations of a', b\ c\ will evidently form with each other
angles which are vertically opposite, and therefore equal, to
those made by «', b\ c'. They will therefore answer to the
conditions of the problem, since they are arcs of great circles
making with each other angles equal to the given angles.

5. It ought to be remarked that a'\ U\ c" do not form on
the surface of the sphere, a triangle in the ordinary sense
of the term : they do not form a space nsihiclithey hound isoith-
out intersectiiig it. The truth is, however, that in both plane
and spherical trigonometry, so far as the computation of sides
and angles alone is concerned, we have nothing to do with the
surface of the triangle, or with any surface whatever; the
lengths of lines and their relative positions being the sole sub-
ject of consideration. Thus, when the three sides of a sphe-
rical triangle are given, to find the angles, the problem is
simply this: Given three points on the surface of a sphere^ to

find the angles made by the great circles passing through them.
So likewise, when the three angles of a spherical triangle are
given, to find the sides, the problem, without reference to a
triangle, is simply, to fnd three points on the surface of the
sphere^ such that the arcs joining them may make with each other
angles equal to given angles : and it is easy to see that other
problems may be expressed in a similar way ; and that the
same views, as well as some others in this paper, may also be
extended to plane triangles.

6. The problem in which two sides of a spherical triangle,
and the contained angle are given, to compute the remaining
angles and the third side, may also be viewed in a similar
light. Thus, the third side is found by means of the for-
mula

cos a — cos A sin 6 sin c + cos b cos c ;

and it is plain, that a will have two values of the forms a' and
(fl"=)2 7r— a'. The smaller is that which is recognised by
the writers on trigonometry as the third side ; while the other
is the remaining arc of the great circle of which a' is one part.
This will be illustrated by taking on a common globe a point

M

2* Prof. J. Thomson on the true and extended

above the horizon, and drawing from it two arc?, b and c, of
great circles to the horizon. Then, if we regard these two,
and the angle which they form, as given, we shall have one
triangle, which will answer the conditions of the problem,
bounded by 6 and c, and the less arc of the horizon joining
their extremities ; while with the greater or remaining arc of
the horizon they will form another triangle, which will an-
swer equally. The latter triangle is evidently composed of
the former, together with the hemisphere below the horizon.
7. The remaining angles will be found by the formulae

^ „ cot bsmc — cos A cos c
cot B =

and cot C =

sin A
cot c sin 6 — cos A cos b

sin A

From these, since cot Q = cot (tt-}- Q), we shall have values
for B and C of the forms B', C\ and tt + B', tt-^-O, which
evidently correspond to the triangles above mentioned.

8. When a side a, and the adjacent angles B and C, are

given, the remaining sides may be found by means of the

formulae

, cot B sin C + cos C cos a
cot b =

and cot c =

sm a

cot C sin B + cos B cos a

sin a

These give values for b and c, of the forms b\ d, and it-\-b\
ttH- c/; the first of which are the values adopted in the books
on trigonometry. The meaning of the others will appear if
we enunciate the problem thus: Two great circles being
drawn through B and C, the extremities of a given arc a of
a great circle, and making with it given angles ; it is required
to find the distances between the points B and C and the two
points of intersection of these circles. These circles will in-
tersect in a point A ; and if they be continued through that
point each to a distance equal to tt, they will again intersect
in a point A". C A and B A are evidently the arcs i'and (/;
while C A A" and BAA" are respectively tt + ^' and %'\-d.
The third angle comes out, as it ought, of the forms A' and
2 ST — A', the former being the angle at A, and the other the
one at A".

9. The case in which there are given a side and the opposite
angle, and either another side or another angle, to resolve the
triangle, may be treated in a similar manner; but neither
case presents any difficulty, and they exhibit nothing remark-

%

Interpretation of Formults in Spherical Trigonometry, 23

able in addition to what has been pointed out in the other
cases.

10. I shall conclude with some remarks which naturally
arise from what has been already said.

(1.) Dr. Simson and others define a spherical triangle as
being " a figure upon the surface of a sphere comprehended
by three arcs of three great circles, each of which is less than
a semicircle" The words in italics should be omitted. Ana-
lysis, as we have seen above, detects the error, and shows that
a side may be of any magnitude not exceeding a complete
circle. An author, as the writers on trigonometry have done,
may properly confine his attention to triangles having each of
their sides less than a semicircle, but he ought not to state
that there can be no others.

(2.) The proposition is not true, in which it is asserted,
that " the three sides of a spherical triangle are together less
than a circle." For a triangle understood in the ordinary
meaning, (as bounded by three arcs of great circles, without be-
ing intersected by them,) the limit is ^lijo circles, instead of one.
To illustrate this familiarly, let us take two points, A and B,
on the horizon of a globe, very near each other, and a third
C, nearly diametrically opposite to them, but above the hori-
zon ; then draw the smaller of the arcs joining A C and B C.
By these two arcs, and by the greater arc of the horizon, the
sphere will be divided into two triangles, each having one side
almost a circle, and each of the others nearly a semicircle.

(3.) Neither is the proposition true, in which it is asserted,
that " any two sides of a spherical triangle taken together, are
greater than the third side." It is easy to see, by taking one
of the sides almost a circle, and the others small, that one
side may exceed the sum of the other two in any ratio what-
ever.

(4.) The assertion is likewise erroneous, that " the sum of
the three angles of a spherical triangle cannot be less than
two right angles, nor greater than six." The true limits are two
right a?igles and ten right angles. To illustrate this, let the
surface of a sphere be divided into two triangles having ex-
tremely small sides. Then, the angles of the smaller triangle
being A, B, C, those of the other will be 2 tt— A, 2 ?r— B, and
2 TT— C. The sum of the former will be 7r4- E, where E may
be as small as we please; while, by adding the others, we
find for their sum 6 7r — (A + B + C), or 6 7r— -tt— E, or finally,
5 TT— E; that is, ten right angles wanting E.

(5.) The area of a spherical triangle may be of any magni-
tude between zero and the surface of the sphere.

(6.) The same principles explain some things regarding the

24 Demonstrations of certain Points in

spherical excess, which seem to have been hitherto over-
looked. Thus, E being the spherical excess, the known
formula

. ,^ v^ sin s sin (s— «) sin (5 — ^;) sin (5— c)
sm in* — + ; -, — -J -.

— 2 cos h a cos ^ b cos ^ c

gives for ^ E, on account of the double sign +, or of the two
values belonging to sin ^ E, or — sin \ E, two values, of the
form \ E' and 2;r— |E', and, consequently, for E the two
E' and 4 7r — E'. Now, the less of these, suppose E', answers
to the smaller of the two triangles formed by a, b, c, and the
other to the greater. For the excess in the former is
A + B + C— -tt; while in the latter, it is S^r— (A + B + C), or
57r— (tt + E'), or, finally, I-tt— E'.
(7.) In like manner, the formula

1 + cos a + cos b + cos c

cot i E = + o,/ ♦ • , X • / /^ • / \f

— ^V sm 5 sm [s—a) sm {s—b) sm [s—c)

gives for \ E, on account of the double sign, values of the
form \ E', and 2 tt— i E'. So likewise, from Lhuillier's formula

tan iE = + >/tan |^ 5 tan \ {s—a) tan i [s — b) tan \ {s — c\

taking the value of tan \ E first positive and then negative,
we find for \ E values of the form \ E^ and t:—\ E'; whence
E will be of the forms E' and 4 tt — E', as before.

,. \ -n 1 r 1 , -r. cot 1 fl coti6+cosC

(8.) From the formula cot ^ E = ^ ^^ ,

^ ' ^ sm C

which gives the excess when two sides and the contained angle
are the data, we find |^ E to be of the forms \ E'and 7r + | E';
whence the forms of E will be E' and 2 tt + E^ This answers
exactly to the two triangles mentioned in No. 6 ; since the
excess E' in the smaller is A + B-l-C— tt, and in the larger
A + TT + B + T + C— TT, or, by contraction, 2 tt + A + B + C — tt,
which is the same as 2 tt + E'.

Glasgow College, Oct. 21, 1836.

VI. Demonstrations of certain points in Fresnel's Theory of
Double Refraction^ deduced from the Investigations of the
LJyidulatory Theory isohich have recently appeared in this
Journal. By A Correspondent.

To the Editors of the Philosophical Magazine and Journal,

Gentlemen,

¥ DO not know whether the following results are sufficiently

■*• original to authorize an expectation that you will be able

to afford them a place in your Journal, as, at the most, they

Fresnel's Theory of Double Refraction, 26

are but demonstrations, in perhaps a somewhat new form, of
one or two points of Fresnel's Theory of Double Refractions.
Such as they are, however, I submit them to your notice, as
obvious and satisfactory deductions from the vahial)le papers
on the undulatory theory which have recently appeared in your
periodical.

On reference to Mr. Tovey's communication in the January
number, 1836, (vol. viii. p. 8,) it will be seen that

If wi, Wi, 7??2, &c. be the molecules of an elastic medium,

ar, y, 2, the coordinates of rest of tw,

X -\-hpy -^k^,z ^-l^ ofm^

&c

y^ = Vhf + kf + If, &C. = &C.,

and if, the system being disturbed, the displacements of m at
the time / be z/, x;, w || the coordinate axes, those of m^
u + ^fU, V -i- ^fV, w + dfW, &c., then the accelerating forces
on m in consequence of the disturbance will be

^m {<pr .^u + {h^u -\- kdv + nw)/l^lfr} || ^,

^m {^r,'8v -{■ (hdu + k^v -\- Idw) k^r} \\y,

Sm{(pr,^w-]-{h^u + khv + n'w)l^i;r} \\ z,

f r f^T f r

where 4> r =^-—i 4/ r = "^— ^ — "^-j, the action of a molecule

771 on another at the distance r from it in the direction of their
distance being m f r, and the sign f extending to all the
molecules within the sphere of m's action.
Now at the beginning of the motion we have

d,u = ^^u= &c. = — M,

8^ v = §2 w = &c. = — t;,

S^tt) = §2^ = &C. = — -KJ,

m„ mg, &c. not having yet been disturbed ; and . • .
initial force \\x = Au -\- Hv + Gw = p

{A cos a + Hcos^ + Gcosy},

\\^ ^iUu + Bv -\- Fw = p

(Acosa+Bcos/3 + Fcosy}, UA,)

\\z=:Gu + Fv-i-Cw = p

{ G COS a + F cos /3 + C cos y I

where p is the whole displacement of the molecule, making
4r s a, /3, y with the axes, and

Third Series. Vol.10. No. 58. Jan, 1837. E

2fi Dcnnonstrations of cert am Points in

B= -fm((^r +yt«^J/r), G = - ^mht^r,

being quantities depending only on the nature of the medium,
and not at all on the quantities p, a, jS, y, though in the same
medium they may vary with the position of m. Hence if R
be the whole force on w, developed by its displacement p, and
X, fj., V the Its its direction makes with the axes, we have
R =z p k, where

K« = ( A^ + G^ + H2) cos"- « + (B2 + F^ + H*) cos« ^,
4- (C2+ F^ +■ G^) cos^y + 2 H (A + B) cos a cos A
H- 2 G ( A + C) cos a cos y + 2 F ( B + C) cos /3 cos y,

and K cos X = A cos a + H cos /3 + G cos y,
K cos jx = H cos a 4- B cos /3 + F cos y^
K cos V = G cos a + F cos |3 + C cos y.

Generally, therefore, the whole force on m a displacement,
but does not act in the direction of the displacement. More-
over, from the linear form of the equations (A) it appears that
we must obtain the same values for the component initial
forces on tw, and therefore the same whole initial force, both
in magnitude and direction, whether we suppose the whole
displacement p communicated at once to m, or the component
displacements w, v, w separately communicated, and take the
sums of the separate forces which would be thus produced.

Suppose now there be a direction of displacement, such that
the whole force developed on m acts in the direction of the
displacement, i. e. that A = a, [jI' = ^9 " = y? then our three
preceding equations assume the well-known form of the equa-
tions which occur in the investigation of the principal axes of
a body, and the cubic resulting from the elimination of cos X,
cos [X,, cos V, will be

(K-A) (K-B)(K-C) -F2(K- A) - G2(K~B)
- H^(K - C) = 2FGH.

The results, therefore, will be similar in the two cases, i,e,
there will always be three, and generally only three, such di-
rections.

Suppose we have determined one of these, take it for
axis of z; then, since a displacement in direction of this axis
produces a force also in that direction, it follows from (A) that
F = G = 0, and that for this axis K = C. Suppose also that
the plane of x z passes through another of the axes, then to
determine its position we have the equations

FresneFs Theory of Double Refraction. 27

A cos a = K cos a,
H cos a = 0,
C cos y = K cos y.

Hence if K does not again = C, we have y = — , and . • .

« 5= 0, H = 0, and K for this axis = A ; if, however, K again
= C, which cannot happen, as appears from considering the
first of these equations, unless A = C y, and therefore a re-
mains indeterminate, H vanishes, and K = C = A. If, then,
A and C are unequal, this second axis is X ** the first ; but
if A = C, any axis in a certain plane passing through the first
possesses the required property ; and in either case the value
of K for this axis is A ; similarly with respect to B and C.
Giving then the name of axes of elasticity to a set of three rec-
tangular axes, through a molecule possessing the property un-
der consideration, it follows (since the same inferences which
have resulted from supposing the axis of z determined as
above would have been deduced from the same supposition
with respect to the axes of a: and ?/,) that there is at least one
set of such axes through every molecule of a medium. Take
these then as axes of coordinates ; then if A, B, C are unequal
there can be but one set ; if any two of A, B, C, e.g. A, B, are
equal, there are an infinite number of sets, having one axis,
that of 3, common to each ; if A, B, C are all equal, any set
of rectangular axes through m are axes of elasticity.

Retaining the axes of elasticity as coordinate axes, we have
F = G = H = 0 ; and the initial forces put in play on m by
separate displacements w, v, w respectively || axes of ar, j/, z
will be A M, B t;, C wj respectively, and will act in the direction
of the displacements; and.*, the whole initial force put in
play on w by a displacement p, making *:s a, /3, y with the
axes, will be the resultant of the three, p A cos a, p B cos /3,
p C cos y, and will . • .

= p K = p VK^ cos^ a + B^ cos2/3 + C2 cos2 y,

in a direction making fe s X, /a, y with the axes, such that

K cos A = A cos a, K cos jtt r= B cos /3, K cos v = C cos y,

and therefore not generally coincident with the direction of
displacement.

It follows also from a comparison of some of the chief pro-
perties of the principal axes of rotation, that

1. The resolved part in the direction of an axis, inclined at

E5^

28 The Rev. R. Murphy o?i a fiew Theorem in Analysis,

"^fes a, ^, y to the axes of elasticity, of the force put in play
on w by a displacement p || it

= p {Acos^a + Bcos^/S +Ccos^y}:

2. The sum of such resolved forces in the directions of any
three rectangular axes is constant

= p{A+B + C}:

3. The force produced by a displacement in the direction
of one of the axes of elasticity is the greatest, and in that of
another the least that can be produced in any one direction
by the same displacement in that direction.

I am, Gentlemen, yours, &c.

St. John's College, Cambridge, C. J.

Aug. 24, 1836.

VII, On a new Theorem in Analysis, By the
Rev. Robert Murphy, M.A.

T APLACF^ first gave a very simple and elegant demon-
■^^ stration of the theorem generally known as Lagrange's,
by taking the partial differential coefficients of u relative to x
and a, from the equation y =■ a + x (^ (y), where ti =y {y) ;
and the simplicity of the process depends on the manner in
which X enters this equation, namely, as a multiplier of a
function of i/,

I have considered a more general equation where x enters
the function in any manner, viz. y = a + <^'(j7, y) and u =zf(y),
and have obtained the following theorem :

When X is changed into x + h, in this equation y and
consequently u are also changed ; let the latter become U,
and let 4> (jt + ^, y) — <^ (^jj/) = A 4> for abridgement; the re-
lation between U and u will then be

da da \^ 1.2 da\

^ da^\\,2,S ' daj^^'''

In proving this we shall use 4> as a contraction of <p {x,y),
and any accented symbol will be used to express the partial

differential coefficient relative to a: ; thus instead of ^^^'^'

ax

we shall simply write 4>'.

Now differentiating the proposed equation y =r a + ^ rela-

Jative to x and a, we get

The Rev. R. Murphy on a new Theorem in Analysis, 29

dy .r,d<t> dy
dx-"^ -^ dy' dx

d y __ d<p dy
d a dy ' da"*

from which we easily obtain

dx ^ • da'

and since m =/ {y\ therefore

du _d u dy du _^du
dx'~dy' dx"* da^dy'

dy
da'

whence du , du

dx'' ^ * da

{' '

CO

Thus far the process is exactly similar to Laplace's, but since
<^' in the present case is not a function of y only, the remain-
der of the investigation becomes essentially different from his.
I put

d"u „ du f/ /n du\ d^ frt du\ _

and now proceed to find the value of the general symbol P„ „,
which is a function both of x and y.

Before differentiating this equation relative to x let it be
observed that

d' P^.n _ p/ d.Vm^n d^

dx -'^"'."■^ dy • dx

_ p/ , ^^»Pm,» ., d y

and also that

da

d du _ d du _^ d / ,du\
dx'da^'da'dx d a\ da)

by equation (1.); from both of which it follows that

(3.)

SO The Rev. R. Murphy on a new Theorem in Analysis.

= ^--- dra'^d^[^-'-''^d-a)'

Applying this formula to differentiate equation (2,) relative
to j:, we get

d'*+^u _ p, du d_ / jy, du\
d^' ~ '""da ■*■ 6/« V ''" dJ

But if we write w + 1 for n in the formula (2.), we also have

d^'u p du d /p du\ cP / du\

d^^ = ^hn+i . ^+ J^l^2.«+i^ j + 5^4^^. »+^ da)

+ &C.,

which compared with the preceding expression shows the
following law for the formation of the functions F„ „, viz.

Pm,n-|-1 = P'»«,n + 4^'- P»n-l,n .... (4.)

And since P;„.i is known, (for Pj ^ = <$>', P2 j = 0, Ps^i
= 0, &c.,) we can thus form successively the quantities P^ 'gj
P^ 3, &c., and the general law of these quantities may be
thus found.

Put

1.2.3 ... m P.,„ = (rP -A^.^ (r-^r^'^^ + B^^^ (r-r-^

-C^^^(<^--f'"^+&c.
Hence

1.2.3 ...,» F„..= (W"^"-A„Mr-r'^"

_A„4.'(r-')"'

_A.*'(r-r"' + 2B„<f$'(r-^r"'

Also

1.2.3 ... m 4^' P^_,, „ = m (^' (<^-if ^"^ - m A^_, ^ <^' (<^'»-^)"^"^

+ 7«B^_,<^2<j>'(r-'r''^ + &c.

The Rev. R. Murphy on a fiew Theorem in Analysis. 31

And by equation (4.) the sum of these expressions must be
equal to 1.2.3 ... m P,„,„+i, that is,

From whence we have
Am = m,2Bm = m A^_i or B^ = -^-^ ^

3 C^ = m B„,.i or C^ = — ^ -^-^^~ ' &c. ;

and therefore

1.2.3 ... m p„.„ = (^-r-^ - ;;2 <^ {r-'r""^

which series terminates at the m^^ term, since (^""-""p"^ = 0.

If we put 1, 2, 3, &c. successively for w in this formula, and
substitute in the expression (2), stopping at P„^ „, we should

c?" u
have -7—^ explicitly obtained ; but there is no necessity for

this.

Again, since A (p = ^ (jr + ^, y) — 4> (jr, y), therefore

(A p)"^ = {^ (ar 4- /?,y)r -rn<p{x, y) {^ {x + A,y)}*»-^

+ !^l!!^) {^ (^^ ^) }2 ^^ (.^ + ^, ^) p-2 ^ &c.

Each term in this series may be expanded according to powers
of h by Taylor's theorem ; and if we take the coefficient of

h* . h^

in each term, the coefficient of -z-rr^- in (A (p)"*

x»z,o ... n l.J.o ... n

is exactly the same as the series (5.).

By this comparison we find that P^^ „ is the coefficient of

h"* . , . n iA(p)'"

rTTiy in the expansion of —-^ — .

1.2.3,,. n ^ 1.2.3 „.m

Recur now to the series (2.), and we get

d" n . h*

-j—„ = the coefficient of ^tttt: in the series following, viz.

^ da^ da\ 1.2 rfflj ^ rfa* L 1.2.3 rfaj ^

32 On the Property of the Parabola

But by Taylor's theorem the same quantity is tlie coefficient

h*
of ,-A a > in the expansion for U — w, we therefore find

the theorem announced at the commencement, viz.

da^ L 1*2.3 da]

We have not space here to point out the applications of
this general theorem, and shall therefore close this paper with
two remarks.

First, if (p [x, y) be of the form x (p (y\ then A <|> = ^ 45 y ;
we have then

?,{(..f.^:}acc.;

h^ ^

1.2.3 d.

and if we suppose jc = 0, then y = a^ and U is then the
value ofy(y) determined from the equation yz= a + h<p {y):
we thus fall on Lagrange's theorem.

Secondly, that if the proposed equation were

^ = F {« + <p (JT, 2/)} and M =/(j/),

the fundamental equation (1.) would remain the same, and
therefore this theorem admits of the same extension that
Laplace gave to Lagrange's. R. M.

VI n. On the Property of the Parabola demonstrated by Mr.
Lubbock in the Phil. Mag, for August, By A Corre-
spondent.

To the Editors of the Philosophical Magazine and Journal.

Gentlemen,

1 N the last [August] Number of your Journal there is a de-
■*- monstration by Mr. Lubbock of a very beautiful property
of the parabola. Mr. L. does not seem to be aware that this
problem, which he ascribes to the French, is in fact due to
Prof. Wallace of Edinburgh, who before the end of the last
century communicated it to Mr. Leybourne, by whom it was
published as a prize question. Not having the book at pre-
sent, I cannot tell in which volume of the Repository it is to

demonstrated by Mr. Lubbock in Phil, Mag. for August, 33

be found, but, if I recollect rightly, there is more than one
solution of it. The most simple way of considering the ques-
tion is undoubtedly by geometry, as the following demonstra-
tion will testify ._

Let A P, A Q, B C be
the three tangents intersect-
ing in ABC. Draw the
diameter F S T, meeting
A Q and A P in S and T.
Join FP, FQ. Then, by
a known property of the pa-
rabola, PFX = 2PTF,
QFX = 2QSF. Also
BAC = PTF + QSF.
Therefore PFQ=2BAC.
Q Again, join F B, F C, F R.
By a property of the para-
bola P F B = B F R and
Q F C = C F R. There-
X fore the salient angle P F Q

= 2 B F C, and all the angles round F or 4 right angles
= 2 (B A C + B F C), or B A C + B F C = 2 right angles,
and therefore a circle can be described round A B C F.

But if an analytical proof of the theorem be required, the
following, by Mr. Greatheed, of Trinity College, deserves
attention from its elegance and brevity.

Let the curve be referred to one of the tangents and the
diameter through the point of contact : then its equation is
y2 = 4< Wi .r ; and the equations to the two other tangents,
whose points of contact are x^ y^ x<^ y,^^ are

y yi = 2 7»i (cT + jTi), ^^2= 2 m, (07 + 0:2).
These tangents will cut the axis of y at distances -^,
and the coordinates of their point of intersection are

Ml.
2

y^ +^2
4. m, ' 2

y\y<i

If t be the angle between the axes, the equation to a circle is

x'^ -\- 2 xy cos ^ -^ y'^ + ax + by + c = 0.
When ;r = 0, ^- + 6j/ + c = 0.

. Therefore

But the roots of this must be ■^,

ThirdSeries, Vol. 10. No. 58. Jan. 1837.

F

34 On the Property of the Parabola

In order that the circle may pass through the tliird poin
we must have

or —^ + (yi + ya) c^^sfl + « + wij = 0, which determines a.
4 W'tj

Hence the equation to the circle is
x« + 2 ^3/ cosfl + / - (^-^ + (yi + y<,) cos5 + m,)

we get

When it cuts the parameter x — m^. Substituting which
t

y^+ (27»'cosfi-^-^jj/-7Wj(y,4-y2)cosa = 0;

the roots of which are obviously — 2 m, cos 5, and ^^—~^.

The first of these shows that it passes through the focus.

We thus see that by the use of oblique coordinates the pro-
blem is simplified in the most remarkable manner, and there
is no necessity for employing the troublesome method of find-
ing the focus, which Mr. Lubbock's solution requires.

As in some degree connected with this subject, I would call
your attention to two properties of the conic sections, which
seem scarcely, if at all, known, and are yet deserving of atten-
tion. The first is due to Keil, and furnishes an easy method
of finding the centre of curvature of a conic section.

Fig. 2.

Let A F N be the axis ; F the focus ; P N a normal meet-
ing the axis in N ; N Q a perpendicular to the normal meet-

demo7istrated by Mr. Lubbock in Phil. Mag. for August. 35

ing the chord through the focus in Q ; Q O perpendicular to
P Q and meeting the normal in O: then O is the centre of
curvature.

The other theorem I found in some manuscripts of the same
period, but it was probably never published. It is as follows :
If a sphere be described round the vertex of a cone as cen-
tre, the latera recta of all sections of the cone made by planes
touching the sphere will be constant, and equal to the radius
of the sphere multiplied by the tangent of half the vertical an-
gle of the cone. I will not add the proofs of these theorems,
as they are attended with no difficulty.

The insertion of this notice will much oblige yours, &c.,

Trinity College, Cambridge. G.

IX. Concise Demonstration of the Property ^f the Parabola
in the Phil, Mag. for August, By the Rev. Hamnett
HoLDiTCH, Fellow of Caius College, Cambridge.

To the Editors of the Philosophical Magazine and Journal,

Gentlemen,

TN the last [August] Number of your Magazine is an elabo-
■■■ rate and ingenious demonstration of the theorem thus stated
by M. Poncelet, " Un triangle etant circonscrit a une parabole,
si on lui circonscrit a son tour une circonference de cercle,
elle passera necessairement par le foyer meme de la courbe."
I venture to propose for insertion the following very short de-
monstration of this theorem : Let (^t'l 3/i)j (^23/2)5 (•^'.sj/a) ^^
the points of the parabola to which the tangents are drawn ;
(X12 Y12) the point where the tangents to the points i^x-^y^
{x^ 1/2) "^^^^ 5 ^h^" ^^ y^ — ^ ^^ ^^ ^^^ equation to the parabola,
the equation to the tangent at the first point is

23/3/1 = Ix + Ixy .-. 2 Y123/1 = /X12 + Ix^

and 2 Yj2J/2 = /X,2 + /.r^;
and we have therefore

X -y^y^ and Y '-yi±2b

A.J2 — — ^ ana 1 12 — ^

Let x'^^y^-\'ax-\-hy-\-c=^0 be the equation to the
circle passing through the three points,

.-. X^2 + Y^2 + « X12 + 6 Y12 + C = 0

and X^23 + Y^ga + « X23 + 6 Y23 + c = 0 ;
F2

36 The Rev. H. Holditch on a Property of the Parabola.

and subtracting the latter from the former, and dividing by
Yij— Y23, we have

-— «r X12--X2S xr , Y I « ^12 ~ ^23 I 7, _0'

19 + A23. ^ -^ - + I12+ J^23 + ^' V _ V + ^ — ^>

*12 — ^23 •*^12 ^23

but Y.,-Y,=3^^ and ^,,-X^^.y-^MirJ^,

• • Y — __ Y " ^/ ' ^^ *^ r • 3^1 + 3^3'

"' anrY,+ Y, =?^i+-^|l±i^:
and therefore

12

yi -^3/3'^r2 ^ .Vi + 23/2 + 3/3 ^ ?_^2 ^. ^ = 0.

And similarly

y^-^yx'^ y\ , .^2 + 23/3+ 3/1 . ^ «y3 . ;: _ „

ana o- ^, ^ »

and substituting these values in the equation X^jg + Y^
+ a Xj2 + b Y12 + c = 0, we have

„_y^y<l +^1.^3 + .^2^3

To find where the circle cuts the axis make ?/ = 0 ;
r , x^ -\- a X ■\- c — % or

\ / 4? / * 4 '

- (X,,+ X,3 f X,3 + 4).^ -f?^- -^ X^^3 + X,3,^^^^

or ^^ — X12 + X23 + X13J . ^or — — j=0;

.♦. 0 = x — X12 + X23 + Xi3 and 0 = .r — — ,

and the latter factor shows that the circle passes through the
focus of the parabola.

August, 13, 1836.

or

«.2

[ 37 ]

X. On the Classification of Vegetables, By the .
Rev. Patrick Keith, F,L.S,*

/CLASSIFICATION may be defined to be the arranging
^^ of the productions of nature in a system, so as either to
show the mutual relation which the several subjects or groups
of subjects bear to one another in the scale of being, or merely
to facilitate our ascertaining of the names which have been im-
posed upon them by their discoverers or others. In the for-
mer case the classification is natural, and is exemplified, as
far as regards plants, in the arrangements of Jussieu. In the
latter case the classification is artificial, and is exemphfied, as
far as regards plants, in the arrangements of Linnaeus. After
all, this distinction, as M. Raspail well observes tj is more
trenchant in expression than in reality, as every good classifi-
cation will have something in it both of the one quality and
of the other.

Linnaeus, as every one knows, founded his classes chiefly
upon the number of the stamens, and his orders upon the
number of the styles. But as distinctions arising from num-
ber merely are of themselves entirely artificial, so is the sy-
stem that is founded upon them. They do not necessarily give
any indication of natural groups, and yet it is singular enough
that this artificial system has brought together several tribes
of plants that are perfectly natural, as the Grasses, the Papilio-
naceae, the Cruciferae. Still the study of it gives the disciple
but little knowledge of a plant beyond the name. He counts
his stamens and pistils, and becomes a perfect master of classes
and orders ; but of the interior and more recondite parts and
properties, whether of stem or of flower, by which different
genera are allied and connected together, that is, of the natu-
ral affinities of plants, he knows nothing. Yet this, asLinnagus
himself admitted, is the grand end and aim of all botanical
investigation. " Methodus naturalis, hinc, ultimus Jinis Bota-
7iices est et erit J." If he had ^xxtfuit into his maxim it would
still have been equally true, for all inventors of systems, even
from the earliest times, have had an eye to a natural me-
thod. The very division of plants into herbs, shrubs, and
trees, the oldest and most popular of all, as well as the most
humble in its pretensions, is founded upon a presumed or ap-
parent affinity between the subjects of its different groups.
This division is at least as ancient as the age of Theophrastus,
if not, rather, as ancient as that of Moses, who speaks of grass,
herb, and tree as comprehending and exhausting the whole of

* Communicated by the Author.

t Chim. Organ., p. 84. \ Phil. Bot., p. 137.

58 The Rev. P. Keith on the Classification of Vegetables,

the vegetable kingdom. In later times, — that is, after the pe-
riod of the decline of learning, and interval of the dark ages, —
when science began to revive and the seeds of sound investi-
gation to take root, botanists began also to introduce into
their lovely study the principles of sound arrangement. Caesal-
pinus, Ray, and Tournefort may be named as individuals who
contributed much towards the introduction of a natural system,
although they were not fortunate enough to stumble upon the
true foundation on which alone it can be made to rest. Lin-
naeus himself lent his able aid, and in his Fragments of a Na-
tural Method exhibited to the botanical world the proofs of
his qualification for the task. There is no saying how far he
might have proceeded in the prosecution of his plan, if it had
not been that he was so much occupied in the perfecting of his
artificial method, — a mere stepping-stone to his natural me-
thod,— that he could not find time for the perfecting of both.
But by thus showing his disciples an easy and royal road to
learning, he unfortunately, and without thinking of it, adopted
the very means of preventing the student from entering upon,
or following up, the intricate and uninviting path that leads by
slow degrees to the elevated station from which he may discern
the beauties, and appreciate the value, of a natural arrange-
ment.

Yet this laborious and uninviting task was at last under-
taken, and prosecuted with a success beyond all that could
have been expected. The principal part of the achievement
is usually ascribed to M. Bernard de Jussieu, and a subordi-
nate part to his nephew, M. A. Laurent de Jussieu, who is
represented as being merely the editor of the writings of his
uncle. This erroneous notion seems to have been taken up
hastily by the contemporary botanists of this country, and
handed down from one to another without much inquiry, till
at last it attracted the notice of M. Adrien de Jussieu, as oc-
curing in the Introduction to the Flora Indica of Messrs.
Wight and Arnott, and called forth a statement that settles
the respective claims of the uncle and nephew, and corrects
the error that had become too prevalent with regard to them.
(Annales des Sci. Nat,, Nov. 1834.)

From this we learn that the uncle suggested indeed some
of the grand outlines of the Genera Plantarum, but gave no
filling up. He adopted the germination of the seed and the
relative disposition of the sexual organs as the only true ground
of all systematic arrangement. He formed families, but not
classes, and left, in short, nothing in writing but the manu-
script catalogues of the garden of Trianon. He died in 1777.

But the Genera Plantarum secundum Or dines Naturales dis-

The Rev. P. Keith on the Classification of Vegetables. 39

posita, as published in 1789, is something more than a mere
catalogue, and M. A. Laurent de Jussieu is something more
than its mere editor : he is, in fact, its author. He could not
have been the editor of the writings of one who wrote nothing.
He could not have gathered all that was necessary to the com-
position of the Genera Plantarum from a few occasional con-
versations with his uncle. He could not have produced that
chef-d'oeuvre of botanical and logical arrangement without years
of close and previous study. Besides, many facts necessary
to its final completion were not even known at the time of his
uncle's death. Hence we see why the work was not ready for
publication before 1 789. Hence we see what portion of it is
to be ascribed to the uncle and what to the nephew ; and we
must beware of detracting from the merits of the one for the
purpose of enhancing the merits of the other.

In this profound and elaborate work the subjects of the ve-
getable kingdom are distributed into three grand groups, Aco-
tyledonous, Monocotyledonous, and Dicotyledonous plants.
The sections are founded on the peculiarities of the corolla,
and the classes on the insertion of the stamens. Still the ad-
vocates of the sexual system say that the method of Linnaeus
is not more artificial than that of Jussieu, whom they accuse
of founding his sections merely on number, as Linnaeus founds
his classes and orders *. But it should be recollected that it
is under very different circumstances. Linnaeus selects a single
species of organ, — the stamens — and all plants furnished with
the same number of stamens are thrust into the same class
without reserve, let their natural affinities be what they will.
Indeed, natural affinities are not so much as looked for. Thus
you have the Asperifoliae and the Umbelliferae, the Bugloss
and the Bulbocastanum, associated in the same class, without
any connecting link, apparent or presumptive, beyond that of
their having the same number of stamens; and thus you are
under the necessity of separating the single genus Anthoxan-
thum from the natural family of the Grasses, because it happens
to have but two stamens to its flower instead of three, which
the rest of the grasses have. In the class Dodecandria the
stamens should be twelve, but by special allowance they may
be from eleven to nineteen. The orders exhibit the same in-
congruities. In Diandria Monogynia, you have Enchanter's
Nightshade and Common Ash placed side by side ; and in Pen-
tandria Digynia, you have Cuscuta and Ulmus. The styles of
Icosandria Pentagynia are by special privilege also allowed to
be from two to five. Yet these incongruities are not to be se-

• Roscoe on Arrangements, Linn. Trans., vol. xl. [or Phil. Mag. and
Annals, N.S., vol. vii. — Edit.]

40 The Rev. P. Keith on the Classification of Vegetables,

verely censured, seeing that the sexual system is actually and
professedly artificial.

But in the system of Jussieu several important traits of affi-
nity are already determined before the class is fixed. All
plants composing the classes of the first grand group are al-
ready connected by the link of their being cotyledonous, that
is, by a character founded on the structure of the embryo, and
its mode of growth. All plants composing the classes of the
Dicotyledons and Monocotyledons are further connected by
their being respectively exogenous or endogenous, accordingly
as they belong to the former or to the latter division, that is,
by a character founded on the structure of the stem and its
mode of growth. These characters are evidently and essen-
tially natural. The Dicotyledons are subdivided into minor
groups, upon the ground pf their being furnished with a calyx
and corolla, or with a calyx only, a character found to be of
the greatest importance in bringing together natural orders,
though not infallible ; and the subdivisions are distributed into
sections, upon the ground of their being polypetalous, mono-
petalous, apetalous, or anomalous. If these last characters
are not absolutely natural, they are at least absolutely neces-
sary to give facility to the investigations of the student, and
are to be admitted till better characters are discovered ; and
if you say that they are founded on number merely, it is not
exactly so. It is upon structure rather than upon number,
a character of more value. For the distinction lies between a
corolla, the petals of which are free, and a corolla, the petals
of which are united, or it depends upon the absence of a co-
rolla altogether.

Lastly, from the several sections, the classes themselves,
which are fifteen in number, derive their immediate origin, upon
the principle of the insertion of the stamens, as being hypogy-
nous, perigynous, or epigynous, characters evidently affinial*,
and very available to Linnaeus in the circumscription of hisl2th,
13th, and 20th classes; for how. without their aid, could he
have brought together so many plants connected by natural affi-
nities where his styles and stamens might not have been easily
counted? Number is no doubt the work of nature, as well as
other characters, but it is found to be liable to great mutabi-
lity, by an abortion, or by an undue multiplication of parts,
and is consequently not to be depended upon in the circum-
scribing of orders or of genera. It is but a fallacious mark
at the best, if taken by itself; for although the genera belong-
ing to a natural order may have all the same number of styles
and stamens, yet all plants having the same number of styles
and stamens do not belong to the same natural order. Hence

• [See Lond. and Edinb. Phil. Mag., vol. v. p. 206, note.— Edit.]

The Rev. P. Keith 07i the Classification of Vegetables. 4V

it is not from any single trait of resemblance that natural or-
ders are to be determined, but from the sum of the affinities
discoverable in the number, form, structure, and position of the
several organs composing the stem, leaf, flower, fruit, or seed,
the organs last developed being regarded as the most important.
Such is the sure foundation on which the system of Jussieu
is built; but still its merits were not at first duly appreciated,
whether in France or in other countries. The eclat which the
name of Linnaeus jjave to the sexual system was such that no
system standing in opposition to it was likely to succeed. Its
novelty, its facility, its beauty, were attractions that could not
be resisted. Hence Jussieu had man}' prejudices to encounter,
and a host of adversaries to discomfit, before he could divest
the natural system of the dreaded difficulties which the study
of it seemed to involve, and to present it to the botanical stu-
dent in a fair and favourable light. Yet, ii^ spite of all ob-
stacles, its superiority to every other system forced itself at last
upon the notice of botanists, and began to make converts even
from among the disciples of Linnaeus. In France, the late JVi.
Richard, the Chevalier Aubert du Petit Thouars, M. Mirbel,
and the elite of the French school were amons the first to
enrol themselves under the standard of Jussieu; m Germany,
Kunth, Von Martius ; and in Switzerland, M. DeCandolle.
But the botanist whom we regard as having distinguished
himself the most conspicuously in the elucidating and perfect-
ing the system of Jussieu, is our celebrated countryman and
fellow- Li nnaean Dr. Robert Brown, as may be seen by con-
sulting liis Prodromus Florce Nova Hollaridics, or his papers
published in the Linnaean Transactions, particularly that on
the Proteaceae of Jussieu, and on the organs and mode of fe-
cundation in theOrchideae and Asclepiadese; together with that
on the genus Rafflesia, followed by a paper read at a meeting
of the Society, June 17, 1834, in which he completes his ^c-
count of Rafflesia Arnoldi, VLnd creates a new order, which he
denominates Rafflesiaceae*; all discovering a profundity of re-
search, an acuteness of discrimination, and a peculiarity of tact
in seizing the essential character that connects or disunites the
subjects of his investigation, which, without his assuming any-
thing of bold or of arrogant pretension, have elevated him to
a rank beyond that of all his competitors, and established his
claim to the compliment that was formerly paid to Linnaeus,
namely, that of his being emphatically, and in the estimation
of botanists themselves, Botanicorum facile princepsf. We

* [An abstract of Dr. Brown's paper was given in Lond. and Edinb. Phil.
Mag , vol. V. p. 70. — Kdit.]

t Arnott, Encyc. Brit.y art. Bot.
Third Series. Vol. 10. No. 58. Jan. 1837. G

42 Mr. MacCuUagh o?i the Laws of Crystalline Befcxion,

cannot on this occasion pass by without notice Mr. Professor
Don, of Kin<);'s College, London, whom we regard as occu-
pying a very elevated station among the botanists of this coun-,
try, and second only to Dr. Brown in the number of valuable
contributions with which he has enriched the Transactions of
the Linnjean Society, all tending to advance and to illustrate
the system of Jussieu.

[To be continued.]

XL Qn the La-ws of Crystalline Beflexion. By James Mac-
Cull a gh. Fellow of Trinity College^ Duhlin*

TN a Number of PoggendorfiT's Annalen (No. 6, for J836,)
^ which reached Dublin late in November, there are some re-
marks by M. Seebeck on a paper of mine which appeared in the
last February Number of this Journal, (vol. viii. p. 103). That
paper contains a general theory of reflexion at the surfaces of
crystallized media ; and M. Seebeck, in comparing the results
with his own experiments, has fully confirmed some of my
formulae, while he has shown that others are defective. I have
therefore been obliged to revise my theory, and I have ascer-
tained that it was vitiated by the introduction of a certain re-
lation among the quantities denominated pressures, which,
foUowinfT the example of M. Cauchy, I had supposed to be
concerned in the problem. This relation I had observed to
hold in the case of singly refracting media, and I concluded,
without any other reason, that it would hold good generally.
But though it led to the correct formula for the polarizing
angles in different azimuths, it was nevertheless arbitrary and
unfounded; and therefore it is now banished entirely from
the investigation, the place which it occupied being supplied by
the natural and simple law of the preservation of vis viva^ while
everything else remains as before. 1 hope the imperfection
of my first essay will be excused, when it is considered that
the erroneous proposition bears but a small proportion to the
whole theory, and moreover, that the general problem, which
I undertook to re;Solve, is one that has not been attempted by
any other person, although the want of a solution has long
been felt. The difficulties which we have to deal with, in en-
tering upon this problem, are not mere mathematical difficul-
ties, but difficulties arising from the want of first principles ;
and, in physical questions of this kind, where we must, at the
outset, have recourse to conjecture, in order to supply the very
principles of our reasoning, it can hardly be expected that the
whole truth should be divined at once. I think, however,

* Communicated bv the Autlior.

Mr. MacCulIagh on the Laisos of Crystalline Rijlcjcion. 43

that I have now obtained a true mechanical theory ; and if
so, it will help to decide, not only the question immediately
before us, but also the other much-disputed, though more
elementary, questions concerning the density of the aether in
tlifferent media, and the direction of the vibrations in polarized
light. In fact, a particular supposition respecting each of the
latter (juestions is included in my theory, the several prin-
ciples of which, making the single alteration that has been
mentioned, I shall here enumerate :

1 . The density of the aether is the same in all media.

2. The vibrations of plane-polarized light are parallel to the
plane of polarization.

3. The vis viva is preserved.

4. The vibrations are equivalent at the common surface of
two media.

To these may be added the definition of the polarizing
angle of a crystal; namely, the angle of incidence ^t which
the plane of polarization of the reflected ray becomes inde-
pendent of the plane of polarization of the incident ray. At
the polarizing angle, the former plane does not, in general,
coincide with the plane of reflexion, but makes with it a small
angle which may be called the deviation. >

It is curious that, about a year and a half ago, I employed
these four principles, precisely as I have now enumerated
them, in deducing Fresnel's well-known laws of reflexion for
ordinary media ; but I did not then apply the law of vis viva
to crystals, because my mind was preoccupied by the notion
that there existed some relation among the pressures. This
notion I had taken up from reading a little paper, by M.
Cauchy, in the Bulletin des Sciences Mathematiques for July
1830; and by combining such a relation with the three con-
ditions afforded by my own law of equivalent vibrations^ I
had actually obtained, for the polarizing angles in different
azimuths, a foruiula (that marked (5.) in my former paper,)
which I found to agree very well with Sir David Brewster's
experiments, and which M. Seebeck has found to agree still
better with his own.

The formula for the polarizing angle is obtained by equa-
ting two values of the deviation ; and it is remarkable that the
very same formula comes out in my present theory, although
the values of the deviation are entirely different. Referring,
for brevity, to the notation* of my former paper, I find, for
the case of a uniaxal crystal,

tan /3 = cos (2*4- 4>) tan 6, (at.)

* Erratum in former paper, vol. viii. p. 106, line 2 from bottom, for

-^ -|- 0 read ~ B.

G2

'H- Mr. MacCullagh on the Laws ()f Crystalline Reflexion.

r' /• . /\ * fl/ . / « 7o.sin\l;'cos\|;'sin^i ,, .

-tau^ =cos(^ + ?)cotan(l +(a'-i')^^,-^._^ ^._^,^ (J.)

These equations (a.) and {b.) are to be substituted for
equations (2.) and (3.), which are the equations that M. See-
beck found to be at variance with his experiments.

By means of formula (5.), e(|uation (a.) becomes

/3 = -g- sin 2 gr sin {p-<^), (c.)

from which the deviation in any azimuth may be readily cal-
culated. The azimuth (as M. Seebeck reckons it) begins
when, 5 = 0, and p is then positive. This formula (c.) perfectly
represents the experiments of M. Seebeck on Iceland spar.
The corresponding expressions for biaxal crystals may be
easily deduced, and will be given in a paper which I am pre-
paring to lay before the Royal Irish Academy.

At the time of my last communication 1 was not aware that
the case in which the plane of incidence is a principal section
of the crystal (or the azimuth = 0,) had been solved by
M. Seebeck, and that formula (T.)? which I regarded as my
own, had been obtained by him long before.

It remains to say a word respecting the new principle of
equivalent vibrations, the most important, perhaps, of all, as
it is certainly the simplest that can be imagined. If we con-
ceive an ajthereal molecule situated at the common surface of
two media, it would seem that its motion ought to be the same,
whether we regard the molecule as belonging to the first me-
dium or to the second. Now the incident and reflected vibra-
tions are superposed in the first medium, and the refracted
vibrations in the second ; and therefore we may infer (when
the phase is not changed by reflexion or refraction), that if the
incident and reflected vibrations be compounded, like farces
acting at a point, their residtant will be the same, both in length
and direction, as the resultant of' the refracted vibrations simi-
larly compounded. This is the law of equivalent vibrations,
and it gives, at once, three equations. A fourth e(juation is
aftbrded by Fresnel's law of the vis viva ; and thus we have
the four conditions necessary for a general solution of the
problem. From the principle of equivalent vibrations, as we
have stated it, it follows that the vibrations resolved parallel
to the separating surface are e(juivalent in the two media; and
in fact, this part of the general principle was assumed by
Fresnel ; but the other part, namely, that the vibrations per-
pendicular to the separating surface are equivalent, was not
assumed by him, nor is it by any means true in his theory.
It appears then that three conditions only are afforded by the

Dr. Kane on Pyroxylic Spirit. 45

hypotheses which Fresnel successfully employed in solving ths
problem of reflexion from ordinary media. These hypotheses,
therefore, are not sufficient when a})plied to ciystals ; except,
indeed, in the case before alluded to, where the azimuth = 0,
which l)as been solved by M. Seebeck. It should be observed,
that though the reasons which I have assigned for the prin-
ciple of equivalent vibrations are extremely simple, yet it was
not by such simple reasoning that I was led to it originally.
Trinity College, Dublin, Dec. 13, 1836.

XII. Researches in Organic Chemistnj, — First Series, Contri-
butions to the History of Pyroxylic Spirit and of its derived
Combiiiations. By Robert J. Kane, M.Z)., M.RJ.A,*

'\/i Y residence in Giessen during the summer of the present
•^^■'- year [1836] allowed me to continue under the guidance of
Professor Liebig the examination of pyroxylic spirit^ and the
compounds obtained from it, which I had commenced prior to
my becoming acquainted with the results of Dumas and Peligot,
and of which a portion was presented to the British Associa-
tion assembled in Dublin during August 1835t.

As sent into commerce pyroxylic spirk is contaminated by
the presence of a volatile oily material, from which it is ex-
tremely difficult to obtain it free. Dumas states that the
impurities are completely separated by distillation with fresh-
burned lime, a process which in my hands at least has never
perfectly succeeded. The pyroxylic spirit thus obtained is al-
ways rendered milky by admixture with water, and conse-
quently unfit for accurate examination. Caustic potash and
sulphuric acid were found equally unsuccessful in removing
this impurity, from which, however, the pyroxylic spirit is ob-
tained free by the following simple process.

Chloride of calcium being dissolved in pyroxylic spiritin con-
siderable quantity, so much heat is evolved that the liquid if
in considerable mass rises to its boiling point, and on cooling
there is deposited a compound of pyroxylic spirit with chlo-
ride of calcium in large brilliant six-sided tables, like those of
acetate of zinc. This compound requires for its decomposi-
tion a temperature much higher than that of boiling water.
If therefore, the rough pyroxylic spirit be saturated with
chloride of calcium and distilled, the excess of spirit and the
oil come over, and are collected as long as by temperature
of a water-bath the distillation conthiues. When this has

* Communicated by the Author.

f [An abstract of Dr. Kane's paper presented to the British Association,
will be found in Lond. & Edinb. Phil. Mag., vol. vii. p. 397, and a notice
of the results obtained by MM. Dumas and Peligot at p. 427 of the same
volume, of which see also p. 395. — Bdix.]

46 Dr. Kane*s Contributions to the Histortj

ceased, a quantity of water is to be introduced into the retort
equal in volume to that of the pyroxylic spirit employed. 1 he
water rephicing the spirit in the combination with chloride of
calcium, the latter fluid is set free and distils, perfectly free
from oil, but mixed with water, from which it can readily be se-
parated by one or two distillations over recently ignited lime.
The substance thus obtained was employed in the following
experiments:

The boihng point atO'74-4' met. barom. press, was 60° cent.

Analysed with the apparatus of Liebig 0*765 gramme of
material gave

Wat^ - 0-853

Carbonic acid 1 •04'2

From whcHce follows the composition :

Carbon... = 37*66 Dumas's theory gives 2 car. = 37*97
Hydrogen 12*39 8 hyd. 12-40

Oxygen... 49*95 2 oxy. 49*63

100- 100*

By the following experiment the specific gravity of the va-
pour was determined by the method devised by Dumas :

Excess of weight of balloon filled with air ) 0-049

over that of the same filled with vapour J & -

Volume of balloon = 269*5 centim. cubic.

Residual air 12*5 cub. cent.

Temperature of vapour 97*75 cent.

Temperature of air 17*0 cent.

Barometer = 0*744 metre.

From these data follow :

Weiijht of a litre of vapour at 1 , . -„„

. /. ^ A /A -^ r = 1*4563 fframme.

temp. 0 cent, and pressure 0- , 6 J °

Density of vapour (air = 1) 1*1210

The theoretical density is 1*1105

The density found by Dumas ... 11200

The results of Dumas and Peligot may, therefore, be consi-
dered as completely established.

The formation of the first hydrate of methylene (the me-
thylene aether) is the most important fact in the whole of
Dumas's researches, as upon the idea of its basic reaction rests
the similarity of the methylene with the alcohol series. The
mode of analysis used by the French chemists consisted in
the detonation of the gas with oxygen : in the repetition of the
experiment I substituted a process in which the relation be-
tween the (juantities was expressed by weight, a method less
liable to error than that of measure.

The gaseous rtiethylic aither was dissolved in water, which

ofPyroxylic Spiril, and of its derived Combinations, 47

was obtained quite free from atmosphoric air by having been
boiled for a long time, and then allowed to cool in closely
stoppered vessels. A quantity of this solution was placed in a
small retort, with which was connected a long tube containing
fragments of chloride of calcium, to the other extremity of
which was attached a tube containing black oxide of coj)})er,
and standing in connexion with the ordinary apparatus of
Liebig for absorbing the products of the combustion. The
tube with oxide of copper liaving been carried to a dull red
heat, the retort was warmed until it began to give out pretty
copiously the gaseous methylic aLther, which streaming over
the red hot oxide of copper gave water and carbonic acid.
The process was continued until there were obtained :

Water generated by the combustion = 1'286 gramme.

Carbonic acid 2*071

giving ^

Hydrogen 1411 1000 rr., 1000 6H

^ -^ , ^ ~ •=. = . 1 heory = — p_

Carbon 5726 4058 ^ 4083 2 C •

The ratio of the carbon and hydrogen is the same as in al-
cohol, and as given by Dumas and Peligot; and as the atomic
weight has been accurately determined by the analysis of the
sulpho-methylates by Dumas and by myself, the basis of the
methylene series is put beyond the possibility of doubt.

I have considered this confirmation of Dumas's view of
the methylene alcohol and aether sufficiently important to be
brought forward, and shall now pass to the examination of
some results to which the French chemists did not attend.

Of the Compowid of Chloride of Calcium with Pyroxylic
Spirit. — This body, to which allusion has been already made,
crystallizes readily in large six-sided tables (rhomboidal): ex-
posed to the air it rapidly deliquesces, absorbing water, and
pyroxylic spirit becoming free, but over sulphuric acid the
crystals can be obtained completely dry. The analysis was
made simply by rapidly weighing a portion in a platinum
crucible, heating it gradually until all pyroxylic spirit was
driven off, and then fusing and weighing the residual chloride
of calcium. The result was as follows :

Pyroxylic spirit... = 3*168 : 53*3, or 2 atoms = 5^'5QS

Chloride of calcium 2*776 : 46*7, or 1 atom 46*435

Grammes 5*944 100*0 100*000

It therefore corresponds to the alcoholates [alcoates] ex-
amined by Graham*.

Of the Oil which accompatiies Pyroxylic Spirit. — In the

* [Mr. Giiham's paper on the Alcoates was reprinted in Phil. Mag. and
Annals, vol. iv. p. 265.— Edit.]

48 Dr. Kane's Contrihutio7is to the Histm'y

rectification of the difFerent quantities of p\'roxylic spirit used
in the foregoing and subsequent experiments, 1 had an op-
portunity of collecting a certain quantity of that oil, to the
presence of which I have had already occasion to allude. The
quantity, although very small, allowed the determination of
some of its most remarkable characters and of its composi-
tion.

This oil is colourless when first procured ; by exposure to
the air and to hght it becomes coloured. Its odour is aromatic
and resinous. Although, as we have seen, readily passing over
in vapour with pyroxylic spirit at the temperature given by
a water-bath, yet alone its boiling-point is very high. The
quantity in my possession was, however, too small to allow of
my determining it exactly. This oil is very light; it floats not
only on water, but on every mixture of pyroxylic spirit and
water by which it is not dissolved. The oil, having been
purified from spirit by distillation, and from water by contact
with chloride of calcium, gave the following analytical results:

From 0*388 material were obtained,

Water = 0-377

Carbonic acid = 1'176;
from whence follows the composition :

Carbon = 83*78 or, 20 atoms carb. = 84*18
Hydrogen 10 79 30 atoms hyd. 10*32

Oxygen 5*4'3 1 atom oxy. 5*50

100*00 100-00

A second analysis was made a few days afterwards with the

same oil, but which had in the interim become coloured by

the action of the air.
0*335 material gave

Water 0*316

Carbonic acid 0*991 ;

from whence follows :

Carbon = 81*73 or, 20 atoms carb.

= 81-93

Hydrogen 10*33 30 atoms hyd.

10*05

Oxygen 7*94' 1| atom oxy.

8*02

100*00 100*00

It thus appears that in the interim the oil had absorbed
half an atom of oxygen from the air.

The formula (C20 H^q O) is the same with that obtained
by Fremy for resinain, from which body this oil is distin-
guished by its physical properties. The two substances are
isomeric, but as none of the combinations have been examined
for either, nothing can be said as to the relation between their
atomic weights. This oil absorbs chlorine with considerable

of Pyroxylic Spirit, and of its derived Combinations, 49

rapidity, there is mucli heat disengaged, and a large quantity of
muriatic acid gas formed, together with a dark brown heavy
liquid, the detailed examination of which was prevented by
the smallness of the quantity of oil in my possession.

Action of Chlorine on Pyroxylic Spirit, — In the memoir of
Dumas and Peligot these distinguished chemists touch upon
the action of chlorine on pyroxylic spirit but slightly ; and
I have found in my experiments a remarkable deviation from
their account, so far at least as the accompanying phaenomena
are concerned.

In order to examine the nature of this reaction I employed
in the first instance the apparatus used by Professor Liebig
in the formation of chloral, but was obliged to abandon its
use from the great violence of the action that ensued. Every
bubble of dry chlorine that came into contact with the pyr-
oxylic spirit produced an explosion, with flame^ the deposition
of carbon, and separation of muriatic acid ; and if a few bubbles
passed through the spirit without being absorbed and mixed
with the vapour in the upper portion of the apparatus, a still
more violent explosion took place, which generally drove the
mass back into the vessel containing the sulphuric acid by
which the chlorine had been dried. As light could not be
completely excluded from acting on this apparatus, the fol-
lowing arrangement was substituted for it. The retort, in
which chlorine was disengaged, was connected by a bent
tube with a three-necked bottle containing sulphuric acid.
In the second neck of this bottle was inserted a safety-tube
dipping into the acid, and from the third issued a bent tube
which passed through one opening of a two-necked balloon,
and dipped into the pyroxylic spirit contained in it. With
the second neck was connected the refrigerating apparatus of
Liebig, which delivered the condensed fluid into a second
two-necked globe, from which a tube conducted the disengaged
muriatic acid gas to a solution of potash, in order to prevent
the inconvenience of its escaping into the atmospheric air.

The balloon containing the pyroxylic spirit having been
carefully covered with thick paper so as almost perfectly to
exclude the light, the stream of dry chlorine was absorbed
completely and much muriatic acid generated. After some
time the action becomes less intense, and the balloon requires
to be warmed to favour the escape of the muriatic acid formed.
At the end of the reaction there are found in the balloon two
li(juids of different densities, one light, watery, and intensely
acid, the other extremely dense, and generally coloured by
carbon deposited in the ex})losions, a few of which are almost
unavoidable. This heavy liquor possesses the following pro-

TJfird Series, Vol. 10. No. 58. Jan, 1837. H

50 Dr. Kane on Pyroxylic Spirit.

perties : it appears to be nearly as dense as sulphuric acid, tastes
sour, reddens litmus-paper, probably IVom adhering muriatic
acid, and had a very high boiling-point; with water it came
over very readily, but alone it generally left a dark-coloured
residue in the retort, and muriatic acid was set free.

Its composition was determined in the following manner :
analysed with oxide of copper,

(No. 1.) 1-113 gramme material gave

Water = 0-185

Carbonic acid = 0890 ;
(No. 2.) 0*992 grannne material gave

Water ..= 0*162

Carbonic acid = 0*787 :
from whence results per cent.

No. 1. No. 2.

Carbon = 21-75 21-94-

Hydrogen... = 1*73 I'Sl.

In these two analyses there came over with the current of
carbonic acid gas and watery vapour a small quantity of sub-
chloride of copper, which depositing itself with the water, ren-
ders the hydrogen estimate much too high. As in analyses of
this kind this source of error is almost unavoidable, two ana-
lyses were made with oxide of lead, which, though producing
but an imperfect combustion of the carbon, gave a result for
hydrogen which I consider as nearly true. Thus with oxide
of lead,

(No. 3.) 1*430 material gave 0*172 water, whence results
rs^ of hydrogen per cent ;

(No. 4.) 1*136 material gave 0*143 water, whence results
1*39 of hydrogen per cent.

To determine the chlorine, the vapour of the body was de-
composed by ignited lime ; the mass of lime dissolved in di-
luted nitric acid, and the chlorine precipitated by nitrate of
silver : in this way,

(No. 5.) 0-892'^of material gave 2*416 chloride of silver, or
66*82 of chlorine per cent. ;

(No. 6.) 0-544 of material gave 1*452 chloride of silver, or
66*0 per cent, of chlorine.

These results are representetl with tolerable accuracy by the
formula,

6 atoms carbon = 458*622 2280

6 chlorine = 1327*950 66*17

4 hydrogen = 24959 1*24

2 oxygen = 200' 000 9*89

2011*531 100*10.

On the Reflex Function of the Spinal Marro%\ .51

This formula I do not bring forward as absolutely fixed, but
as rendered extremely probable by the analyses detailed above,
and by the reactions which are observed in the decomposition
of this body by bases, a subject to which I shall recur in an-
other series of these researches.

[To be continued.]

XIII. On Professor Miiller's Account of the Reflex Func-
tion of the Spinal Marrow*. Communicated by Marshall
Hall, M,D., F.R.S,, S^c.

^INCE the publication of my Memoir on the Reflex Func-
^ tion of the Medulla Oblongata and Medulla Spinalis, in-
serted in the Transactions of the Royal Society for 1833, I
have been greatly gratified to find that Prof Mialier, the justly
celebrated physiologist of Berlin, had been led, entirely inde-
pendently of me, into the same path of investigation, — to
nearly similar results, — and even to the adoption of the same
designation f for the special function of the spinal marrow
which is the subject of my inquiries.

Prof Miiller states, as will appear from the paragraph of
which, by the kindness of Mr. Paget, I am enabled to send a
translation, that the first part of his Handbuch, containing
the principles of the reflex function, was published in the
spring of 1833, the very year in which my paper was published
in the Philosophical Transactions];. 1 had, however, read a
short account of the same principle of action in the spinal mar-
row, to the Zoological Society, the year previously, viz. 1832,
which was published in the " Proceedings of the Committee,"
and referred to in theLond.&Edinb. Phil. Mag., vol.ii. p.477;
so that the question of priority of publication is decidedly in
my favour. At the same time, the almost perfect coincidence
in our observations and experiments, and in our conclusions
from them, is at once most remarkable and satisfactory. The
name of Prof. Miiller will not fail to give importance to the in-
quiry ; and, for my part, I recall to mind, with pleasure, the
remark of Sir Humphry Davy, that " we may generally dis-
cover how our labours will be appreciated eventually, from
the opinion of contemporary foreigners, who being unbiassed
by circumstances of personality, will reduce every object to
its just proportions and value."

* Handbuch der Physiologic.

t Prof. Miiller goes further. He says — "The spinal marrow has the pro-
perty of reflecting sensorial impressions made upon the sentient nerves, to
the motor nerves. // is a rejlector,'^ &c. (Opus cit., p. 789.)

t [A notice of the reading of Dr. Hall's paper before the Royal Society
was given in Lond. & Edinb. Phil. Mag., vol. iii. p. 460. — Edit,]

H2

52 Prof. Muller and Dr. M. Hall

*' Of the Reflexion in the Motions after Perceptions.

" The observations which are brought forward in this Chap-
ter are new, and denote a remarkable progress in our science.
They relate to phoenomena of the so-named sympathetic mo-
tions after perceptions, which were formerly very liberally sup-
posed to be exercised by the sympathetic nerve, though it may
be clearly proved that they take place quite independently of
it. As the phasnomena belonging to this class are uncommonly
numerous, and include a great part of the phaenomena which
were formerly without any proof attributed to the sympathetic
nerve, the use of the sympathetic nerve in the explanation of
nervous sympathies seems constantly to diminish. How much
this part of physiology has altered, is clearly seen, by com-
paring the explanation of a great part of the nervous sympa-
thies which the admirable Tiedemann investigated in the year
1S25*. The explanations of the sympathies by means of the
sympathetic nerve, in fact, explain everything and yet nothing.
Thus, as this work will fully show, the most evident and fre-
quent sympathies between the uterus and mammae, the paro-
tid and testes, the larynx and testes, are quite inaccessible to
these explanations. We will not positively say that the sym-
pathetic nerve does not take a part in any of the sympathetic
phaenomena, but we do altogether deny that the sympathetic
nerve participates in all the so-called sympathetic phaenomena,
which will be examined in this chapter, and we think it very
probable that the sympathetic nerve is generally unconnected
with the greatest part of those sympathies, in which motions
take place after perceptions, or perceptions after other percep-
tions, or motions after motions. The explanation of sympa-
thies by nervous connexions had been already made very ques-
tionable by the microscopic anatomy of their primitive fila-
ments. For how could this explanation be received, when at
present, though we know of connexions of the fasciculi of the
nerves, we are acquainted with no union of their primitive
filaments? A mere nervous connexion, therefore, without any
ganglion on the part, cannot of itself in the present state of
the science explain any sympathy.

" The phaenomena now to be examined were observed at
nearly the same time by Dr. Marshall Hall and myself. As
the greatest part of the ' Nervenphysik/ as here given, was
completely prepared several years since, so also this Chapter
on the reflected motions after perceptions, was written down
almost exactly as here given several years ago. That this

• Zeitschrift fiir Physiologic, i.

* " The system of the respiratory nerves maybe thrown into morbid action,
producing convulsive motions, by local stimuli in all parts which are pro-
vided with mucous membranes. Stimuli applied to the mucous membrane
of the nose, produce sneezing ; in the pharynx, oesophagus, stomach, or in-
testines they produce the concurrence of the respiratory motions, in vomiting;
while powerful stimuli in the rectum, urinary bladder, or uterus, produce a
concurrence of respiratory motions in the involuntary discharge of faeces or
urine, or the expulsion of the foetus. Stimuli of the mucous membrane of
the larynx, trachea, and lungs, nay, even a stimuhis exciting a tickling in
the Eustachian tube, produce cough.

" All these involuntary motions, cough, vomiting, spasmodic involuntary
discharge of faeces, the forced passage of urine, are produced with the assis-
tance of the respiratory motions. The local stimulus here acts from the
inner membrane of the viscus, on the branches of the sympathetic ramifying
therein, and in the stomach, pharynx, trachea, and lungs, on the branches of
the vagus which they receive, or in the nose on the nasal branch of the tri-
geminus, and is reflected to the source of the respiratory motions in the me-
dulla oblongata and to the spinal marrow, from which proceed the groups of
respiratory motions that produce vomiting, cough, sneezing, &c. Stimuli
of the nasal branches of the trigeminus produce sneezing, even when se-
condary ; for instance, when the stimulus of the sun's light acts first on the
optic nerves, the latter act on the brain, and the brain causes a secondary
excitement of the nasal nerves and coincidently of the respiratory nerves.
I, like many other persons, sneeze as soon as I see bright sunlight. Sti-
mulus of the vagus alone in the larynx, trachea, and lungs excites cough,
that of the pharyngeal branches of the vagus and glossopharyngeal in the
pharynx, or of the vagus in the stomach, excites vomiting. We will now go
through the several groups of these sympathetic respiratory motions.

" All the several respiratory motions may be produced in an isolated man-
ner, and sometimes are united in groups, such as do not regularly occur in
respiration.

" The contraction of the diaphragm, united with the motions of respira-
tion, takes place, voluntarily or involuntarily, in the forcible expulsion of a
body from parts of the abdominal cavity ; e. g. voluntarily in the expulsion
of fceces and of urine, involuntarily in vomiting, parturition, involuntary ex-
pulsion of faeces after their too long retention, and in the involuntary dis-
charge of urine long retained. The pharynx, stomach, rectum, urinary blad-
der, and uterus, all stand by means of their nerves in such connexion with the
cerebral and spinal nerves, that a violent stimulus applied to any one of them,
excites contraction not merely in it, but also in the abdominal muscles and
diaphragm, to the expulsion of the irritating matter upwards or downwards.
This effect takes place by reflexion to the brain of the stimulus of the branches
of the vagus in the pharynx and stomach, — to the sympathetic system and
to the brain and spinal marrow, from the sympathetic twigs of the stomach,
— and by the reflexion to the spinal marrow of the stimulus of the partly
sympathetic and partly sacral nerves in the rectum, uterus, and urinary
bladder. In all these motions for the expulsion of a part upwards or down-
wards, the glottis is for a long time closed.

" For the explanation of the production of vomiting, an observation of
mine is very instructive, viz. that if we open the cavity of the abdomen in
a rabbit, and having exposed the splanchnic nerve on the left side (near the

5't Prof. Miiller and Dr. M. Hall

of the reflected motions after perceptions, from observations
which will be here further detailed. It is remarkable that

inner side of the renal capsule) tear it with a needle, contraction of the
abdominal muscles often takes place. I have not seen this in the dog.

** In cough, the stimulus of the vagus, in the larynx, trachea, and lungs is
propagated to the medulla oblongata. The medulla oblongata thereupon
excites contraction of the glottis, with spasmodic expiratory motions of the
thoracic and abdominal muscles, by which at each expiratory action, the
j)reviously closed glottis is somewhat opened and a loud tone produced.
The diaphragm has nothing to do with the cough, except that sometimes a
deep inspiration is made before coughing. According to Krimer^ and Bra-
chet, after division of the vagus on both sides of the neck of an animal,
cough can no longer be excited by violent stimuli of the internal surface of
the trachea. It certainly, however, may, according to Krimer, after division
of the sympathetic nerve in the neck.

" We have the power of closing the entrance into the larynx, not merely
by the closure of the glottis, but even in the fauces from the nasal and oral
canals. Dzondi discovered that this takes place by the approximation of the
posterior arches of the palate, which lie almost hke two curtains approach-
ing each other from the sides, and by the apposition of the posterior part of the
tongue against this inclined plane. This motion always precedes sneezing.

" Sneezing is a violent sudden contraction of the expiratory muscles, after
the air-passages anteriorly have been previously closed. This closure changes
at the momentof the violent expiration into a sudden opening of the oral and
nasal canals together, or of the latter alone. Sneezing has nothing whatever
to do with the diaphragm, which so many ancient and modern authors have
supposed to take a part in it. The widely spreading nervous sympathies
appear quite unnecessary in the explanation of sneezing. In the false suppo-
sition that sneezing is effected by the diaphragm, it was thought that the
stimulus of the nasal nerves was propagated to the deep twig of the Vidian,
and to the sympathetic, and from thence to the cervical and the phrenic
nerves. Even Arnold still speaks of this. Now as the expirat'ory muscles
(with previous closure of the mouth and nose) produce the act of sneezing,
and not the diaphragm, the simplest view is to regard the medulla oblongata
itself as the medium between the nasal branches of the trigeminus, the ex-
piratory muscles, and the muscles of the velum palati, after the analogy
of the sympathetic motion of the iris by the stimulus of light. For in this
case, as may be clearly shown, the stimulus of light acts neither imme-
diately on the ciliary nerves, nor from the retina to the ciliary nerves.
Tlie arteria centralis is indeed, according to Tiedemann's discovery, accom-
panied by a fine twig from the ciliary ganglion. But this twig is distributed
on the arteria centralis retinae, and is in no proved connexion with the re-
tina. In complete paralysis of the retina, light in general no longer pro-
duces contraction of the iris, though still through the healthy eye it does
produce a contraction of the iris of the diseased one. (There are however
exceptions to this rule, which Tiedemannhas collected in his Zeitschriftfur
Physiologie.) The motion of the iris therefore probably results from a re-
flexion of the stimulus of the retina to the brain, from the brain back to the
oculo-motor nerve, and the ciliary ganglion. The sympathies of a great
part of the nerves with a local stimulus through the medium of the brain
and spinal marrow, are very well shown in the phaenomena following the
narcotization of an animal, in which a slight touch on the skin produces ge-
neral tetanic spasms." — pp. 333 — 335.

* Untersuchungen uber den Husten.

oti the Beflex Function of the Spinal Marrow, 55

the same ideas, with the same instances and observations
on narcotized animals, were propounded in the same year by
JDr. Marshall Hall, in the Philosophical Transactions of 1833.
Although these ideas were formed by us independently of each
other, yet the great correspondence in the observations and
explanations is not difficult to account for, if one considers,
that the physiology of the nerves has attained a condition, such
that in pursuing the subject the most remote observers may
at the same time be led to similar new observations and ex-
planations. I shall in the following pages first communicate
my own observations, as they were originally formed, and
shall then compare them with the results of the English phy-
sician and physiologist.

"When perceptions, which are produced by external stimuli
on sensitive nerves, produce motions in other parts, this never
takes place by a reciprocal action of the sensitive and motor
filaments of the nerves, but by the sensorial excitement acting
on the brain and spinal marrow, and from these back to the
motor filaments. This extremely important principle in phy-
siology and pathology requires a strong proof, which may be
very clearly attained empirically, and then explains a number
of physiological and pathological phenomena.

" I shall first prove that the motor and sensitive filaments of
a nerve, after the connexion of their two roots, do not enter into
any connexion with one another, but run separately to their
respective parts, and that therefore, even in cases where the
nervous sympathy is not in play, the sensitive and motor fila-
ments of a nerve have no reciprocal action whatever.

" The proof of this position may be shown clearl}' in the fol-
lowing manner: If a compound nerve be stimulated (after
being divided,) at its central portion, severe pain is produced,
and the animal may express this pain by motions of flight,
crying, &c. ; but the muscular nerves connected with the sti-
mulated portion are not excited to action. No twitchings
take place in the muscles which receive nerves from the divi-
ded trunk.

" It may also be proved in the following way : As the three
nerves destined for the posterior extremity of the frog form a
plexus, which again gives off two nerves, so, if one of the lat-
ter nerves be divided and isolated from all its connexions
with the muscles, and then the central portion be mechani-
cally stimulated, the injury produces a centripetal excitement
of the sensitive fibres of this nerve ; but the other nerves,
proceeding from the same plexus, do not, when the isolated
nerve is injured, excite any twitchings in their muscles.
That moreover, the general twitchings that ensue on any

56 On the Reflex Function of the Spinal Marrow.

Touch, in narcotized frogs and other animals, are only pro-
duced through the medium of the spinal marrow and brain,
may be decisively proved ; for if a limb be cut off' from a
narcotized frog, touching it (the limb) will not produce
twitchings in it. These experiments are still more instruc-
tive in the lizard.

"The spotted lizard retains for a long time after division of
the spinal marrow, the so-named sensitive power in all parts
below the section ; or, if this cannot be called sensitive power,
the capability of propagating sensitive impressions to the spinal
marrow, and of re-acting by twitchings. Even the end of
the tail has still perception ; nay, this power is as much ele-
vated by the division of the spinal marrow, as in frogs which
have been previously narcotized : if a portion of its trunk
after being cut off' be only very lightly touched, it always
contracts, and this continues for hours. But this interesting
phaenomenon is only shown when the spinal marrow is still con-
tained in the separated piece, and not in whole limbs separated
from the trunk and not containing any spinal marrow. These
interesting facts I observed several years ago, 1830, when with
Herr Jorclan 1 was investigating the poison of the cutaneous
glands in the spotted lizard. It results from this that the ge-
neral twitchings which take place in animals on touching par-
ticular parts, do not result Irom communication of sensorial
and motor nervous filaments, but that the spinal marrow is
the connecting medium between the sensorial-centripetal and
the motor-centrifugal excitement.

*' The phaenomenon of general twitchings after local percep-
tions is therefore also independent of the sympathetic nerve,
and is induced by an irritation of the spinal marrow, by which
every purely local sensorial-centripetal excitement propagates
itself to the whole spinal marrow and brain, and from thence
of necessity excites all motor fibres. But this irritable con-
dition is excited by the following causes :

" 1. In many animals by the mere division and injury of
the spinal marrow. Thus tortoises move after the head is cut
off*, whenever they are touched; and young birds move on
being touched immediately after decapitation, as do also all
parts of the cut-off* trunk in the lizard.

'* 2. Further, the spinal marrow is irritated to this degree
in the first stage of narcotic poisoning in frogs, as well as in
mammalia, which move after poisoning with nux vomica,
whenever they are touched. This stage of excitable debility
in narcotization almost always precedes the stage of paralytic
debility.

" 3. Other causes also, which debilitate the brain and spinal

Dr. Ritchie's Rcplij to Mr. Uainey. 57

marrow by stimulation, produce the same phaenomenon. In
men with excitable debihty of the nervous system any unfore-
seen sensation, sound, touch, or mechanical shock produces a
general start. So also in men who, by stimulation of the ge-
nitals, and thereby of the spinal marrow, or by other causes,
have acquired an excitable debility of the spinal marrow.
We may here cast a glance at the nature of nervous irrita-
tion. All nervous stimuli may induce in succession three con-
ditions. First, excitement, in which the powers appear still
uninjured. Second, in proportion as the excitement is re-
peated, excitable debility. Third, atonic debility.

" 4. A local violent excitation of a sensitive nerve, may by
the violence of the centripetal excitation of the brain and spi-
nal marrow, induce twitchings and tremblings, as after a se-
vere local burn, in tooth-drawing, &c.

" 5. Local stimulations of the nerves by linflammation or
tumours, often also produce general spasms, or even epi-
lepsy.

"6. The irritation of the spinal marrow, originating from
local sensorial excitement, may in violent injuries be so great,
that the movements are constant, and continue even without
touching. This irritation of the spinal marrow resulting from
severe local nervous injuries, is the tetanus traumaticus.
Every severe irritation of the spinal marrow generally is teta-
nus, whether produced by narcotic poisoning or locally and
indirectly. I have here shown how the production of tetanus
traumaticus is to be explained by simple empirically deter-
mined facts.

" 7. The severe irritation of the sympathetic nerves of the
intestinal canal also excites by acting back on the central
parts general spasms ; and thus the cramps in sporadic cholera,
as well as the convulsions in the diseases of the viscera in
chiklren, are to be explained.

[To be continued.]

XIV. Reply to Mr. Rainey's Communication in the Phil. Mag.
for December 1836. By the i?^u. William Ritchie, LL.D.^
F.R.S., Professor of Natural Philosophy in the Royal Insti^
tution of Great Britain and in the University of London.

To the Editors of the Philosophical Magazine and Journal.

Gentlemen,

TT is not with any wish of having the last word in the discus-
sion of the principles at issue between Mr. Rainey and myself,

but simply with a desire of establishing scientific truth on a
Third Series. Vol.10. No. 58. Jaw. 1837. I

58

Dr. Ritchie's Bephj to Mr. llaiiiey's

firm basis, tliat I again trouble you with the following re-
marks.

Ist. Mr. IJainey's first false position is, that " there is no
known limit at which soft iron ceases to allow of further in-
duction by an increase of the inducing power," and he also
takes for granted, that a magnet having doiible the power will
induce on the same armature twice the effect. The following
experiments must convince every person that the lifter or ar-
mature has a limit to its capability of receiving magnetism, and
that its capability of receiving new increments diminishes ra-
pidly as the inducing power increases.

Roll a covered wire about
the half of an electro-magnet
from A to B. Do the same
with an equal wire from C to
D. Connect the first helix
with an elementary battery,
and ascertain the lifting
power of the magnet. Con-
nect the other helix with an
equal battery, and instead of
the lifting power being dou-
bled, acccording to the principle assumed by Mr. Rainey, its
power may not be increased a third or fourth, or even a tenth,
if the battery be a powerful one.

2nd. The second false principle which Mr. Rainey assumes
is, that the lifter, by its reaction, can induce a higher state of
magnetism in the inducing magnet than what it naturally pos-
sesses. The experiment from which he deduces this novel
principle by no means warrants the conclusion. The experi-
ment every person who knows anything of the subject, knows
to be correct; the reasoning by which the conclusion is de-
duced must be as easily seen to be fallacious. The experiment
is, that a soft steel electro- magnet receives more powerful j>^r-
manent magnetism when a piece of soft iron is across its poles
than it does when the poles are not united. Mr. R. concludes
that " as the induction from the galvanic current was the same
in each stage of this experiment, the increase of permanent
magnetism would appear to depend upon the reaction of the
keeper, which, by the converse of Dr. Ritchie's reasoning, must
then possess a higher state of magnetism than the magnet to
which it is applied." Here again Mr. Rainey takes for granted
that the induction from the galvanic current is the same in the
steel magnet, whether it form a closed circuit, as it does when
its poles are connected by soft iron, or an interrupted circuit,
when the poles are not connected. Now every person who

Communication in the Phil. Mag. for December 1836. 59

has magnetized a closed circuit knows that this is not the case.
The following experiment will set this point at rest : take a
bar of steel, A B, and bend

another of the same size and ' ' > i >

length into a square. Mag- ^
netize the straight bar by draw-
ing it lengthwise over one of
the poles of a magnet ; move
the same pole the same num-
ber of times round the square ; ,

break the bar into four equal parts and the square at the corners,
and the bar C D will be stronger than either portion of the
straight bar. I formerly stated, and again repeat the affirma-
tion, that if Mr. Rainey's explanation be admitted, it v;ill
completely overthrow the Newtonian law c^f the perfect equa-
lity of action and reaction. '* I had always considered," con-
tinues Mr. Rainey, " that law as applicable only to mechanical
forces, and not extending in the least to those physical phasno-
mena, the acting cause of which is altogether unknown.
Suppose a number of pieces of steel, properly tempered, and
for convenience made into the form of the common horseshoe
magnet, and one of them magnetized to saturation ; now, by this
one let all the others be magnetized, and afterwards let them
be put together, and the process of magnetizing be performed
repeatedly upon each of the rest, and it will be found that each
magnet possesses nearly, if not quite as much magnetism as the
one employed in the first instance, that is, as the prime motor
itself. This fact can scarcely be doubted, although it is at va-
riance with the Newtonian law of the perfect equality of action
and reaction as applied to mechanical forces, as no force can
be supposed capable of generating, under the same circum-
stances, a force greater than itself" It is but too obvious from
this quotation that Mr. Rainey has not read the Principia
with any degree of attention, as he has entirely mistaken the
meaning of the law in question. The acting cause of universal
attraction is as much unknown as that of any other physical
phaenomena, yet the law holds as much in this case as in the
case of a man pulling a boat against a stream. The second part
of the preceding paragraph is exceedingly unfortunate as an il-
lustration of a fact at variance with the Newtonian law. No-
thing could be more conclusive in its favour. The following
illustration would be equally applicable : suppose a number of
pieces of wood placed at the mouth of a river, and suppose
they are of such a size, that a man, after fixing a rope to one of
them, is just able to pull it a mile against the stream and fix it
to a tree growing by the side of the river ; and suppose that he

12

60 Dr. Ritchie's RcmarJcs oil the Papers

attain pulls another to the same place and secures it in like
manner, and so on till he has secured the whole raft, and it
will be found that if there be a hundred logs of wood, it will
require the strength of a hundred men to prevent their float-
ing down the stream. This fact can scarcely be doubted, al-
though it is at variance with the Newtonian law, as no force can
be supposed capable of generating, under the same circum-
stances, a force greater than itself.

This communication will, I trust, end a controversy from
which little more scientific truth can be elicited.

XV, Remarks o?i two of the Elect7'ic and Magnetic Commu-
nications in the last Number of the PhiL Mag. ihjthe. Rev.
William Ritchie, LL,D., F.R,S., Professor of Natural
Philosophy/ in the Royal Institution of Great Britain and in
the University of London,*

f\^ no branch of science have there been so 7na7uj writers
^^ and so few readers as on that of electricity and magnet-
ism. This is fully illustrated by all the papers on that subject
in the last Number of the Phil. Mag. (vol. ix. pp. 4-52,469, 472.)
The few remarks which I made on Mr. MacGauley's paper,
read at the last meeting of the British Association, were re-
garded by him as bitter and uncalled-for, though those remarks
related only to want of originality of his communication, as the
facts had all appeared in print before that period. His last
paper in the Phil. Mag. I consider exactly in the same predica-
ment. If papers of this kind pass without animadversion, their
authors will, at least by the uninitiated, be regarded as the real
discoverers of the facts and reasonings contained in them. I
feel that in undertaking; the refutation of alleged claims I am
undertaking an unpleasant and invidious task. Justice demands
it at the hands of some one, and the person best able to do it
is mainly concerned ; he has perhaps wisely left it to others.

The first position claimed by Mr. MacGauley will be found
in a paper of mine in the Phil. Mag. for last June, vol. viii. page
458. His second position is contained in Dr. Faraday's papers
on the length of the coil influencing the spark, and the mutual ac-
tion of the spires of the helices. Mr. MacGauley in his third
position arrives at the strange conclusion that "magnetism with-
in a helix proportionably injures its effect." Dr. Faraday has
clearly shown that it is only magnetism in motion that induces
electricity. If the soft iron be within a coil which has magnetism
induced on it, at the same time that the coil has voltaic elec-
tricity induced on it, and if the temporary magnet in returning
* Communicated bv the Author.

of The Rev. J.W. MacGauley and The Rev. N.J. Callan. 61

to its neutral state tend to induce electricity on the coil in the
same direction with the returning current in the coil, the effecf:
will be increased; on the contrary, diminished, which seems to
be the case which presented itself to Mr. MacGauley's obser-
vation. His fourth position has been known so long that I
scarcely know its discoverer. 8ir H. Davy knew it well, and
endeavoured to investigate the law of diminution in the effect
of the battery depending on the length of the wire connecting
its poles. The only thing new in this paper is the statement
of a fact which is not correct. It is said that if two persons put
their hands in salt water, and if they are placed in the electric
circuit, eac/i receives a more powerful shock than when only
one person was placed in the circuit. That this is not the case
every one who possesses a magneto-electric machine may easily
satisfy himself. (

The paper in page 472, by the Rev. N. T. Callan, is equally
destitute of originality. Tlie battery which he describes has
been known for a long time. 1 had one exactly the same,
made by Mr. Newman six or seven years ago, and frequently
used at my public lectures in the Royal Institution. The au-
thor talks of the "enormous quantity of electricity circulated
by this battery." The quantity is simply, as I have shown in
the Philosophical Transactions, directly as the surface, and
when used as a compound battery, as the square root of the
number of plates. The author speaks of a shock as if it were
a quantity, and institutes a comparison between the size of the
shock and the number of plates. " When two pair of plates
were used the shock appeared to be doubled ; with three vol-
taic circles it appeared to be trebled." This, 1 believe, is the
first attempt to bring sensations under the power o^ analysis.
It is needless to dwell on this paper. The only thing new in
it is the affirmation that an " electro-magnet, when its magnet-
ism is induced by a compound battery of 200 small pairs of
plates, will have a greater power of inducing magnetism at a
distance than any permanent magnet." The very looseness
of this statement is a proof of its fallacy. Does the author
mean to say that a small electro-magnet when connected with
a battery of 200 pairs of plates induces more magnetism on soft
iron at a distance than ani/ permanent magnet? Though he
says so he cannot seriously mean what he says. His meaning
then must be this, that if an electro- horseshoe-magnet have the
same lifting power with a permanent one when the keeper is in
contact with it, it will lift a small piece of soft iron at n greater
distance than the electro magnet. That this is not the case every
person may satisfy himself by the sin^plest experiment. I have
shown it to be so in the Phil. Mag. for last August, (vol. ix.

62 Royal Society.

p. 81,) which the author seems to have glanced at but not
read. In that paper 1 stated that *' the attraction of an elec-
tro-magnet for pieces of soft iron at a distance was much less
than that of a permanent magnet of equal lifting power. This
peculiar property rendered the electro-magnet not well suited
for magnetic induction at a distance; and hence after a few
unsuccessful trials to substitute it for the permanent magnet in
my apparatus for continued rotation, it was long since aban-
doned." It was abandoned for this reason, not because it failed
in producing rotation, but simply because it did not do it so
well as a permanent magnet. The author in question gives the
following version of my statement : " Dr. Ritchie says that the
use of the electro-magnet in the apparatus for continued rota-
tion was long since abandoned, because it was incapable of in-
ducing magnetism in an iron bar at a distance." It is painful to
be forced to notice papers of this kind with which the journals
are constantly filled. It may appear to some that my asser-
tions are too broad. I appeal for the truth of them to every
person acquainted with the present state of the science.

XVI. Proceedings of hearned Societies,

ROYAL SOCIETY.

[Continued from vol. ix. p. 537-]

June 16. 12. " A Comparison of the late Imperial Standard Troy
{Continued.) -^^ Pound Weight with a Platina copy of the
same, and with other Standards of authority." Communicated by
Professor Schumacher, in a Letter to Francis Daily, Esq., V.P. and
Treas. of the Society.

Professor Schumacher being desirous of procuring an accurate
copy of the English Imperial Standard Troy pound weight, for the
purpose of comparison with the Danish weights, applied to Capt.
Kater, requesting him to cause such copy to be made j which was
accordingly done. It was made of brass by Bate j but the result
of the weighings not being satisfactory to Professor Schumacher,
he desired to have a second copy forwarded to him. As these two
copies did not agree in their results, the first was returned to Capt.
Kater with a request that he would repeat the weighings. The re-
sult confirmed Professor Schumacher's suspicions : and as it was
not thought proper that, in an affair of so much importance as the
comparison of the standard weights of two nations, any source of
discordance should exist, or even be suspected, (the preceding ex-
periments having been made with a copy of the Imperial standard
weight) the Danish Government sent over Capt. Nehus (of the
Royal Danish Engineers) to this country for the express purpose of
making comparisons with the original standard, in the possession
jof the Clerk of the House of Coujmons.

Imperial Standard Troy Fotmd. 63

The weighings took place in the Apartments of this Society, and
were partly made with Ramsden's balance, belonging to the Society.
Besides the first brass weight above mentioned, there was another
brass weight made by Robinson, a platina weight made by Gary,
the brass pound weight belonging to the Royal Mint, and the
platina pound weight belonging to this Society. These were all
subjected to a most rigid and accurate series of weighings by Capt.
Nehus, in which every precaution was taken to insure the most
correct results. It would be impossible here to follow Capt. Nehus
through all his details : but it may be sufficient now to state that
upwards of 600 comparisons were made with the English Imperial
standard, all of which are apparently very accordant ; but, on ac-
count of a singular circumstance connected with the ori^/nrt/ stand-
ard, do not possess that degree of precision, nor afford that satis-
faction which ought to attach to an affair of so much importance.
For, it appears that not only the specific gravity of the original
standard had never been ascertained, but that we are even ignorant
of the kind of metal of which it was composed : some persons main-
taining that it was of brass, others of copper, and others of bell-
metal. And, as the original was totally destroyed in the late fire
which consumed the two Houses of Parliament, we cannot now
supply this omission. It is well known that the specific gravity of
brass may vary from 7*5 to 8'5 ; so that a difference of at least ^ of
a grain might arise from this circumstance alone ; setting aside a
number of other particulars that require minute attention, and
which do not seem to have been attended to in former experiments
of this kind. In fact, as Professor Schumacher remarks, though
we have thus five different pounds in excellent preservation, and com-
pared with the lost standard, with the greatest care and the best
instruments, though the number of these comparisons exceeds 600,
yet there still remains an uncertainty as to its real weight; and this
solely on account of its specific gravity and expansion not being
known. And, he adds, that it is to be hoped that no pound will in
future be declared a legal standard unless these elements (the know-
ledge of which is indispensable even for a single comparison with a
good balance) are previously determined with the greatest possible
precision.

Besides the account of these numerous weighings, which are
stated in detail, Professor Schumacher has given various formulae
and tables which will be found of great use and application in any
future experiments of a like kind that may be undertaken.

13. " On the Application of a New Principle in the Construction
of Voltaic Batteries, by means of which an equally powerful current
may be sustained for any period required j with a description of a
sustaining battery recently exhibited at the Royal Institution." By
Frederick W. Mullins, Esq., M.P., F.S.S. Communicated by
N. A. Vigors, Esq., F.R.S.*

The method resorted to by the Author for obtaining a continu-
ous voltaic current of equal intensity, is the same in principle as

• See Lond. and Edinb. Phil. Mag., vol. ix . pp. 121, 283.

61* Royal Society,

the one employed by Professor Daniell, and described by him in
his paper recently presented to the Royal Society, and published
in the Philosophical Transactions ; namely, the interposition of a
thin membrane between the two metals in the voltaic circuit, so as
to allow of the separation of the different fluids applied respectively
to each metal : the fluid in contact with the zinc being a mixture
of diluted sulphuric and nitric acids ; and that in contact with the
copper being a solution of sulphate of copper. The author re-
serves for a future paper the details of the results he has obtained,
with regard to the relations between the intensity of effect, and the
extent and disposition of the metallic surfaces : but states that he
has obtained powerful electric action by bringing the membrane
into contact with the zinc; the latter having no acid applied to it,
and the only fluid employed being the solution of sulphate of cop-
per.

14. Anonymous Essay, entitled "Scoperta della Causa Fisica del
Moto." Presented to the Royal Society, with a view to obtaining
one of the Royal Medals for 1836.

The Author commences by an historical review of the opinions
of almost every philosopher, both ancient and modern, who has
treated of the subject of motion, from Pythagoras to Le Sage: and
proceeds to state his own ideas relating to the cause of motion,
founded on the hypothesis that the ultimate atoms ol" all matter
have a pyramidal figure.

15. " An Experimental Inquiry into the Modes of Warming and
Ventilating Apartments." By Andrew Ore, M.D., F.R.S.

The Author, having been consulted by the Directors of the
Customs Fund of Life Assurance, on the mode of ventilating the
Long Room in the Custom House, and deeming the subject one of
great public interest, was induced to lay the result of his observa-
tions and experimental inquiries before the Royal Society. In this
room, about two hundred persons are busily engaged in transacting
the business of the Institution. All these persons are found to
suffer more or less from ailments of the same general character, the
leading symptoms of which are a sense of fulness and tension in the
head, flushing of the face, throbbing of the temples, giddiness, and
occasional confusion of ideas, depriving them of the power of dis-
charging their duties, in which important and frequently intricate
calcuhitions are required to be gone through. These symptoms of
determination of blood to the head are generally accompanied by
coldness and languid circulation in the feet and legs, and by a feeble,
and frequent, as well as quick and irritable pulse. On examining
the air of the room by appropriate instruments, the author notices
more especially three circumstances in which it differs from the ex-
ternal air: first, its temperature, which is maintained with great
uniformity within a range of 62° to 64°; secondly, its extreme dry-
ness, which, on one occasion, measured by Daniell's hygrometer,
was 70 per cent. : and thirdly, its negatively electrical state, as in-
dicated by the condensing gold-leaf electrometer. In all these
qualities the air respired by the inmates of the room bears a close
resemblance to the pestilential blasts of wind which, having passed

Dr. Ure 07i iVarming a7id Ve.ntilating. B5

rapidly over the scorching deserts of Arabia and Africa, constitute
the Simoom of those regions, and are well known by their injurious
effects on animal and vegetable life. To these noxious qualities is
superadded, as in the air of all rooms heated through the medium
of cast-iron pipes or stoves, an offensive smell, arising partly from
the partial combustion of animal and vegetable matters always
floating in the atmosphere of a town, and perhaps also from minute
impregnations of carbon, sulphur, phosphorus, or even arsenic, de-
rived from the metal itself. The Author expresses his surprise that
in the recent report of the Parliamentary Committee on the subject
of ventilation, no reference is made to the methods employed for
that object in factories, although they afford the best models for imi-
tation, being the results of innumerable experiments made on a
magnificent scale, with all the lights of science, and all the resources
of the ablest engineers. He proceeds to describe these methods ;
and is then led to investigate the comparative efficiency, with a
view to ventilation, of a draught of air resultiiig from a fire and
chimney, and that produced by the rotation of a fan -ventilator.
He shows that a given quantity of coal employed to impart motion
to the latter, by means of a steam-engine, produces a ventilating
effect 38 times greater than can be obtained by the consumption of
the same fuel in the ordinary mode of chimney ventilation. Accord-^
ingly, he strongly advises the adoption of the former in preference
to the latter : and inveighs against the stove-doctors of the present
day, who, on pretence of economy and convenience, recommend
the slow combustion of a large body of coke, by means of a slow
circulation of air ; under which circumstances, it is well known to
chemists that much carbonic oxide, a gas highly pernicious to all
who respire it, is generated ; accompanied, at the same time, by a
comparatively small evolution of heat. In order to obtain the
maximum quantity of heat from a given mass of fuel, its combus-
tion, he observes, should be very vivid, and the evolved caloric
should be diffused over the largest possible surface of conducting
materials ; a principle which has been judiciously applied in several
French factories. It has been proved that work-people employed
in calico-drying rooms, heated according to the plan here repro-
bated, become wan, emaciated, and diseased ; while in rooms in
which the air is more highly heated by means of steam-pipes, they
preserve their health and florid complexion.

16. *' An Experimental Inquiry into the Relative Merits of Mag-
netic Electrical Machines and Voltaic Batteries, as Implements of
Philosophical Research." By William Sturgeon, Esq., Lecturer
on Natural and Experimental Philosophy at the Honourable East
India Company's Military Academy at Addiscombe. Communicated
by P. M. Roget, M.D., Sec. R.S.

The first part of this paper is occupied by a description of two
forms of constructing the magnetic electrical machine, which the
author has adopted ; and the second, with the particulars of some
experiments made with a view to determine the respective powers
of these machines as com pared, with the common voltaic battery.
In the first form of the instrument, a reel, round the periphery of

Third Series. Vol.10. No. 58. Jr/??. 1837. K

66 Royal Society,

which 200 feet of copper wire, one 20th of an inch in diameter and
covered witli stout sewing-silk, are coiled, is made to revolve on a
spindle, placed in the axis of a system of horse-shoe niagnets, so as
to remain within the branches of the latter during its whole revolu-
tion. The electric currents produced in the copper wire by mag-
netic induction, while the coil is moved at right angles to the plane
of the magnets, are conducted by means of four semicircular me-
tallic flanges attached to the spindle, into cisterns of mercury, the
one being positive, and the other negative ; and which consequently
act as the two poles of the battery. In the second form of the ap-
paratus, a piece of soft iron, of which the ends are bent into the
shape of two arms, and which is surrounded with a coil of 300 feet
of copper wire, is made to revolve in front of the poles of a horse-
shoe magnet ; its axis of motion coinciding with that of the magnet;
and the electrical currents determined in the wire by this rotation,
being collected in the same manner as in the former instrument.

Tlie author next details several series of experiments which he
made for the purpose of ascertaining the relation observable be-
tween different velocities of rotation in these instruments and the
corresponding effects : first, with regard to the deflection of a mag-
netic galvanometer ; secondly, with regard to chemical decompo-
sitions; thirdly, with regard to the production of sparks; and lastly,
with regard to the intensity of the shock communicated to the hu-
man body. He compares the effects produced by the magnetic
electrical battery, first, when the coil consisted of one continuous
length of wire ; secondly, when the coil was doubled upon itself so
as to constitute two sets of conductors of half the length of the
former ; thirdly, when, upon being again doubled, it composed four
conductors of one quarter of the length of the first ; and lastly, when,
on being doubled a third time, the electric current was made to pass
through eight wires, each one eighth of the original length of the
single wire. It was found that by thus multiplying the channels of
conduction, although both the magnetic and the luminous effects
continue to be produced with scarcely any sensible difference of
intensity, the power of effecting chemical decompositions becomes
more and more impaired, and the physiological influence is weak-
ened in a still more remarkable degree. In the four-stranded coil, in-
deed, no shock whatever could beproduced, however rapidly the in-
strument was made to revolve. The author endeavours to account for
these variations of effect by the- diminution of velocity in the elec-
tric current, its quantity remaining unaltered, consequent on its
division into several streams by the multiplied channels offered to
its progress. He also tried the effects of conjoining the magnetic
electrical machine with ordinary voltaic combinations ; sometimes
acting in cooperation, and at other times in opposition to one an-
other; and notices the corresponding results, which were sufficiently
accordant with theory.

17. ♦' Welt Mechanik." By M, Kropalschek.

The object which the author has in view, in this paper, is to over-
turn the theory of universal gravitation, as regulating the planetary
motions. The memoir is divided into two parts ; in the first, he dis-

Roi/al Society. 67

putes the accuracy of Kepler's law respecting the description of
equal areas in equal times, and endeavours to confute the funda-
mental doctrines of astronomy relating to the elliptical orbit of the
earth, the difference between solar and mean time, and the whole
theory of the motions of the moon and the planets. In the second
part, the author enters into a detailed exposition of his own views
of the mechanism of the heavens ; and devotes 215 closely written
pages to the development of a perfectly new hypothesis, which he
advances, founded on a supposed variation of the progressive mo-
tion of the planets, in an orbit perfectly circular, and by which he
thinks he can explain all the phaenomena they present to observa-
tion.

] 8. ** Plan et Esai d'un nouveau Catalogue Sideral, avec une repre-
sentation graphique, et une loi de simple et reguliere distribution
des etoiles autour du Pole, qui pourra fournir plusieurs avantages a
J'Astronomie pratique." By Professor Joseph Bianchi, Superinten-
dent of the Observatory at Modena. I

The Author proposes the construction of a new sidereal catalogue,
accompanied with a graphic representation of all the stars visible
within the field of view at each observation, by means of the meri-
dian transit of the most conspicuous stars across the field of a tele-
scope of four inches aperture, attached to a three-feet circle. He
directs this telescope to any elevation of the heavens that happens
to be clear j and bringing any conspicuous star to the horizontal
wire, he watches its transit over the two first vertical threads; then,
suddenly intercepting the light, makes a diagram of all the stars in
the field down to the 12th magnitude ; and this he performs with suf-
ficient expedition to enable him, on restoring the light, to observe
the transit of his principal star over the fourth and fifth threads.
The author has appended to the description of his method explana-
tory drawings, displaying 600 fields, of which the principal star in
each has its right ascension and declination determined. He subjoins
some remarks on the rate of clocks, as influencing the observations
on the upper, lower, and opposite passages ; and proposes a plan
for a systam of symbols expressive of the relative magnitude of the
stars recorded in his catalogue.

The author further states as one of the most important results of
his researches the probable existence of a general and curious law
of position in the stars, namely, that they are distributed in pairs ;
each star having a corresponding one in the opposite meridian, very
nearly o'i the same declination and magnitude ; a coincidence which
he considers as extremely favourable to the execution of his project
for the accurate determination of the position in the heavens of every
star.

19. "On the Composition and Decomposition of Mineral Waters"
By the Rev. George Cooke, LL.B. Commnnicated by J. G. Chil-
dren, Esq., Sec, K.S.

20. " inquiries concerning the Elementary Laws of Electricity,"
Part II. By William Snow Harris, Esq., F.R.S.

21. **A New Theory of the Constitution and Mode of Propagation
'_. K2

68 Geological Society,

of Waves on the Surface of Fluids." By H. J. Dyar, Esq. Com-
municated by Edward Turner, M.D., F.R.S.

The Society adjourned over the long vacation, to meet again on
the 17th of November.

aEOLOGICAL SOCIETY.

Nov. 2, 1836. — A paper was read, entitled ** A general sketch of
the Geologv of the western part of Asia Minor," by Hugh Edwin
Strickland, Esq., F.G.S.

This memoir embodies the observations made by the author during
a winter's residence at Smyrna, a tour into the valleys of the Meander
and Cayster, and a journey from Constantinople up the river Rhyn-
dacus into Phrygia, and thence down the valley of the Hermus to
Smyrna. In the latter excursion he was accompanied by Mr. Hamil-
ton, one of the Secretaries of this Society, to whom he acknowledges
himself indebted for a zealous cooperation.

The country, thus viiiited, is thickly beset with mountains, some
of which are arranged in five parallel chains having, on a great scale,
nearly an east and west bearing, but the remainder are variously
grouped and without any particular direction. Four of these parallel
chains bound the valleys of the Hermus, the Cayster, and the Mean-
der ; and the fifth, commencing with Mount Ida, extends eastward
to the Mysian Olympus, and probably is continued in the Bithynian
Olympus. With respect to the theories which have been advanced
relative to the direction of a range being a mark of its comparative
antiquity, the author says that the whole of the mountains of this part
of Asia Minor, whether parallel or not, appear to have been elevated
at nearly the same geological epoch.

The formations of which the country is composed, Mr. Strickland
arranges in the following chronological order, but he states that
further researches may require it to be modified : 1. Granitic rocks ;
2. Schistose and metamorphic rocks ; 3. Greenstone ; 4. Silutian
rocks; 5. Hippurite limestone j 6. Tertiary lacustrine limestone-
7. Tertiary marine formations ; 8. Trachytic and trap rocks 3 9. Mo-
dern volcanic rocks; and 10. Modern aqueous deposits.

1 . Granitic rocks were not observed in situ, but on the authority
of iM. Fontanier, M. Texier, and other travellers, the loftiest part of
Ida, the Mysian Olympus, the range of the Bithynian Olympus,
Mount Dindymus, the top of Mount Tmolus, and Mount Latmus are
granitic.

2. Schistose and metamorphic rocks. — This class of formations, con-
stituting nearly all the mountain chains, consists principally of mica-
schist associated irregularly with beds of marble and quartz rock,
and is supposed by the author to be altered clays, earthy limestones,
and sandstones. The marble is very generally distributed, but the
chief points mentioned in the paper are the quarries in the island of
Proconnesus, from which the name of Marmora was given to the
neighbouring sea, Broussa, Ephesus, the north and west sides of
Mount Olympus, and the valley of the Cayster. The colour is white,
gray, or striped, and thin seams of mica often traverse the blocks,
giving them a tendency to split into slabs. The quartz rock is in-

Mr. H. E. Strickland on the Geology of Asia Mitior. 69

terstratified with the slate, into which it frequently pT^.^es. The strike
of the beds commonly coincides with that of the mountain range, but
the amount and direction of the dip is said to vary greatly.

3. Greenstone. — It is with some hesitation that the author gives a
distinct place to this rock, as he conceives that it may be of the age
of the trachytes. He observed it between Kesterlek and A(lrian6s,
associated, though not clearly, with the mica slate j and near the
village of Eshen he noticed a vein of greenstone traversing a tertiary
rock, and therefore believes that the extensive greenstone formation
around that village may be tertiary.

4. Silurian rocks. — A formation of schist and limestone containing
many fossils resembling in general character those of the Silurian
rocks, was observed on both shores of the Bosphorus north of Con-
stantinople. Mr. Strickland stated that the formation would be de-
scribed in a separate memoir.

5. Hippurite limestone and schist.— TKx^ term is employed by the
author to designate the vast series of limestones, Which covers a great
area in the South of Europe, and represents in Asia Minor the whole
of the secondary formations. On the south side of Lake Apollonia
the deposit consists of compact, yellowish, lithographic stone, iden-
tical with that of Greece j at Mount Tartali, on the east of Smyrna,
of compact, gray limestone, abounding with large Hippurites, and of
greenish schistose sandstone like some of the Italian macignos; on
the eastern part of Mount Sipylus, above Magnesia, as well as in the
peninsula of Carabornou, and in the island of Scio, it also consists
of gray compact limestone ; and at Mount Corax, west of Smyrna,
of schistose marls and sandstone apparently devoid of fossils.

In addition to these localities, Mr. Strickland says, that on the
south side of the Hermus, between Ghi^diz and Hushak, he and
Mr. Hamilton observed a series of beds consisting chiefly of mica-
ceous sandstone finely laminated, and containing occasionally beds
of rolled pebbles and soft white limestone ; and though the deposit
is unlike any other in Asia Minor, yet he is inclined to class it with
the Hippurite limestone.

6. Tertiary lacustrine limestone. — In the part of Asia Minor de-
scribed in this paper, every large valley, with the exception of the
Cayster, contains remains of extensive lacustrine deposits, forming
occasionally rounded hills several hundred feet high; but they are
totally wanting in the narrow ravines. They consist generally of
horizontal beds of calcareous marl, sandstone, and white limestone,
which is often identical in composition with English chalk, inclosing
layers and nodules of flint; but sometimes approaching in character
to the Italian scaglia. Near the skirts of the deposits the marls and
limestones gradually become sandy and gravelly, resembling in some
instances a shingle beach. The fossils noticed in these beds belong
to shells of the genera Unio, Cyclas, Lymnsea, Planorbis, Paludina,
and Helix, and to leaves of dicotyledonous plants.

As far as the author's observations extended, these testaceous re-
mains resemble more the existing freshwater shells of the North of
Europe than those now inhabiting Asia Minor. Thus the genus Cy-
clas, common in the North of Europe, was not noticed by him in Asia

70 Geological Society.

Minor except in a fossil state ; and the genus Melano|)sis, abundant
in every stream in the country, was not found in the tertiary strata.
The author then gives a detailed account of each lacustrine deposit,
designating it by the name of the valley in which it occurs, or the
principal town in its vicinity. He terms them the basins of Mou-
dania, Doondar, Harmanjik, Taushanli, Gozuljah, Azani, Ghi^diz,
Hushak, Sardis, Smyrna, and the lower vale of the Meander.

7. Tertiary marine formations. — Accumulations assigned to this
class, are stated to occur on the coast of the Troad, both banks of the
Dardanelles, and in the southern part of Tenedos, but they were not
examined by the author.

8. Trachytic and trap rocks. — Patches of these rocks are scattered
abundantly over Asia Minor, and are commonly associated with the
lacustrine deposits, which in some cases appear to be older, in others
younger, than the igneous rocks. The following are the points at
which they were observed by Mr. Strickland and Mr. Hamilton in the
journey from Constantinople to Smyrna: Both sides of the Bospho-
rus, a few miles north of Constantinople ; the promontory of Boz-
bornou, north of the gulf of Moudania ; Hammamli near Kirmasteu
on the Rhyndacus ; between Debrent and Taushanli, where volcanic
matter is intermixed with a lacustrine sandstone ; the vicinity of
Ghi^diz, where a basaltic mass has sent forth a coulee of columnar
amygdaloid, which is 10 feet thick, and rests upon beds of sand and
gravel inclosing pebbles of trachyte ; Gunay ; the hills west of Kobek j
about 8 miles from Adala, on the road to Koola j the western side of
Mount Sipylus; and the hills immediately above Smyrna.

9. Modern volcanic rocks. — These were observed by the author only
in the Catacecaumene, and are termed by him modern, with reference
to geological epochs and not to historical events. He refers them to
two ages, marked by the different degree of preservation of the cones of
scoria and by the appearance of the streams of lava which have flowed
from them. The older cones, 30 in number, are low and flat ; their
craters have either disappeared or are marked by a small depression,
and they are covered almost invariably with vineyards producing the
Catacecaumene wine. The streams of lava connected with them are
also level on the surface and covered with turf. To the north of the
Hermus the author observed many isolated hills of lacustrine lime-
stone, capped by beds of lava or basalt, which he considers may have
flowed from these older cones.

The newer volcanos, of which there are only three, must have
been extinct for at least 3000 years ; yet their craters are perfectly
defined, and their streams of lava are black, rugged, and barren.
One of these craters, visited by the author, is called Karadewit or
the Black Inkstand, and is about 1^ mile north of Koola. It is a vast
mound of reddish scoriae and ashes, has a small crater on the north
side, and an immense sea of black lava containing olivine and augite
has flowed from its base.

As an additional proof of the comparatively great antiquity of these
modern volcanic eruptions, Mr. Strickland describes the effects of a
stream of lava at Adala, a town in the north-east extremity of the
plain of Sardis. The Hermus enters this plain from the Catacecaii-

Lin nee an Society. 7t '■

raene through a narrow gorge between hills of mica schist. A coul6e,
probably derived from the most western of the three newest cones,
has flowed through this gorge and expanded over the plain at Adala.
The Hermus, thus impeded in its course, appears to have flown over
the lava, the surface of which is smooth and bears a stratum of peb-
bles. In course of time the river has worn a channel between the
mica slate and the lava to the depth of 80 feet, completely cutting
through the coulee ; yet so compact is the lava which has escaped the
action of the stream of water, that it exhibits not the slightest tendency
to decomposition.

The author then points out the strong resemblance between the
structure of the Catacecaumene and the volcanic district of Central
France. In each country are extensive lacustrine formations, cones
of scoriae of different ages, coulees, sometimes forming plateaux on
the summits of isolated hills, at others continuous streams, and thick
beds of lava worn through by the action of running water.

10, Modern aqueous deposits. — Under this head a description is
given of the travertine deposited by hot springs between the foot of
Mount Olympus and Broussa, forming an accumulation 2 miles in
length, and at the latter locality half a mile in breadth and 100 feet
high. The water has a temperature of 184° of Fahrenheit, but at
present there are no springs except those at the foot of Mount Olym-
pus.

A description was next given of the changes which have been pro-
duced by sedimentary matter deposited near the mouths of the rivers.
Thus the island of Lade, once the scene of a sea-fi^ht between the
Persians and the lonians, is now a hill in the midst of a plain j the
Latmic Gulf is changed into an inland lake j the once flourishing
town of Miletus, losing its hiirbour, is become a heap of ruins ; the
port of Ephesus is converted into a stagnant pool ; and the delta of
the Hermus threatens in a few centuries to destroy the harbour of the
prosperous city of Smyrna.

The memoir concluded with the description of a recent lacustrine
deposit in the valley of the Rhyndacus above Kirmasteu, which appears
to have been for the greater part removed by the action of that river,
only detached platforms, 50 or 60 feet high, being left on the sides
of the valley.

LINN-ffiAN SOCIETY.

Nov, 1, 1836.— Specimens of the Spartina glabra, a grass new to
the British Flora, were presented by Dr. Bromfield, by whom it was
discovered during the past summer on the muddy banks of the river at
Southampton, growing in great abundance intermixed with the S.
stricta. The species had been previously found only in North America.
It is now in such plenty in the Southampton station that, if really in-
troduced by ballast or other means, it must have been long since
naturalized.

A paper was read, entitled, Observations on the Esula major
Germanica of Lobel. Bv Edward Forster, Esq., Treas. and V.P L S..
F.R.S.,&c. * *

Lobel in his Stirpium Historia, published in 1576, and Johnson

72 TJnncean Society.

in his Mercurius Botanicus, published in 1634, record a species of
Euphorbia^ as growing near Bath, which Mr. Forster has satisfac-
torily proved to be the same with the plant published in the " Sup-
plement to English Botany" under the name oi'pilosa. It is also re-
corded by Merrett in his Pinax, and in the Indiculus Plantarum
Dubianim, inserted by Dillenius at the end of his edition of Ray's
Synopsis. The station as given by those authors answers pretty
nearly to the locality in which the plant is now found. Mr. Forster
regards the E palustris and pilosa as forming but one species ; the
circumstance of the leaves being either glabrous or hairy he consi-
ders as alone insufficient to constitute a specific difterence.

A paper by Mr. Robert H. Schomburgk was also read, On the tree
from which the Indians of the Oroonoko prepare the famous poison
called Wooraly or Ourary. The tree proves to be an undescribed ^^e-
c'lesof St rychnos, and it is worthy of remark thatDr.von Martins found
that the Indians of the Amazon prepare a similar poison from a
nearly related species of the same genus. The mode of preparing
the poison appears to be confined to the Macoosies of Pirarira,
and the Warpeshanas of the Conocon mountains situated near the
equator, where the plant grows wild. The following are the name
and character of the species:

Strychnos toxifera, Schomb.

S. foliis ovato-lanceolatis acuminatis 3 — 5-nerviis utrinque ramulis-
' que ferrugineo-tomentosis, bacca polysperma.

Nov. 15. — A singular specimen of an Orchideous plant was pre-
sented from Mr. Schomburgk, bearing on the same spike flowers of
Myanthus barbatus and Monachanthus viridis of Lindley, which ap-
pear to be nothing more than conditions of the same species, arising
from sexual differences in the flowers. The spike has five flowers of
Monachanthus, and two of Myanthus barbatus. The former remain
in their normal position, but the latter are resupinate. The same
plant produced a second scape with all the flowers of Myanthus
barbatus. In a letter which accompanied the interesting specimen
above mentioned, Mr. Schomburgk mentions a second instance of
the same kind which came under his notice, and that a vigorous
plant which bore at one time flowers of Monachanthus viridis, had,
two months previously to his writing his letter, produced a scape with
flowers of Catasetum tridentatum, which he regards as a third condi-
tion of the same species. He states that he has never observed
Catasetum tridentatum bear seed, but the flowers of Monachanthus
viridis abundantly. This last would seem to be the hermaphrodite
plant, Myanthus barbatus the female, and Catasetum tridentatum
the male. These facts throw an entirely new light on the struc-
ture and oeconomy of this remarkable family of plants.

A letter from Mr. Nicholson, addressed to the Secretary, was read,
giving an accountof a young Haw^nch {Coccothraustes europcea ) ]ust
fledged, but unable to' fly, having been picked up off the ground in
a wood at LuUingstone in Kent, in the month of June last. Its cries

Linncean Society, 1%

on being taken brought the two parent birds to its assistance, and
they continued to fly round in circles, uttering piercing cries, for a
considerable time. The bird is usually a spring visitant, and but
very rarely continues throughout the sunniier, and breeds in this
country. Neither Latham nor Montagu mentions an instance of
its continuing and breeding with us.

Read also a description of the Pithecia leucocephala of Geoffroy
St. Hilaire, the Saki and Yarke of Buffon. By Robert H. Schomburgk.

This monkey belongs to the Plaii/rrhirii, a tribe which comprises
all the American forms, with the exception of the genera Jacchus
and Midas (the Marmzeit monkeys). The adult male is of a shin-
ing black, except the face, and the female is of a brown colour. It
is a native of the interior of British Guiana, about a day's journey
from the banks of the Rupununy, where they were observed by
Mr. Schomburgk in considerable numbers.

Dec. 6. — Flowering specimens of the sea-side grape (Coccoloba
puhescens) were exhibited from the Botanic Garden at Cambridge.

A. B. Lambert, Esq., V.P., exhibited specimens of two sorts of
the Peruvian grain called Quinoa, from his garden at Boyton House,
Wilts, one of which, the dark-coloured kind, he regards as a distinct
species, for which he proposed the nan^e oi' Chenopodium altissimum.
The stenjs exhibited to the meeting were upwards ol 12 feet in height.

Mr. Ward, F.L.S., exhibited specimens of two remarkable para-
sitic plants, one the Aphyieia Hydnora^ from the Cape of Good
Hope, and related to tlie gigantic Rqfflesia of the Indian Islands;
the other Cynomorium coccineum from the vicinity of Mount Sinai,
where it is eaten by the natives. This last is also found in Malta,
Sicily, and Barbary, where, however, the plant is extremely local.

Read, a notice by Mr, Lambert, on the culture of the Quinoa
in Upper Peru, where, on the high plains, at an elevation of
13,000 feet above the level of the sea, scarcely any other grain is
cultivated ; but since the introduction of corn from Europe, the
cultivation of the Quinoa has greatly diminished in Lower Peru
and in Chili.

Read also. Descriptions of two species of the natural order Co"
niferse. By Professor Don, Libr. L.S.

One of these is the Pinus brutiay a native of Brutium or Calabria,
and nearly related to the maritime pine of Greece j the other is the
Araucaria Cunningham ii, from the east coast of New Holland, ob-
served by Banks and Solanderin tiie first voyage of Cook, and since
by Brown in the voyage of Flinders, and by Mr. Cunningham in
that of Capt. King, and in the land expedition of Oxley to the river
Brisbane. We subjoin the characters of these two species.

PiNUS BRUTiA, Ten.
P. foliis geminis praelongis tenuissimis undulatis, strobilis sessilibus
conglomeratis ovatis laevibus : squamis apice truncatis planius-
culis umbilicatis.
Distinguished from P. maritima and halepensis by its very long
wavy leaves, and by its shorter, sessile, clustered cones, with the
scales de})ressed and slightly concave at their apex.
Third Series. Vol. 10. No. 58. Jan. 1837. L

74 Intelligence and Miscellaneoiis Articles..

Araucaria Cunninghamii. Art.
A. decandra; foliis arboris junioris verticaliter compressis spinu-
loso-mucronatis rectis ; adultioris lanceolatis acutis imbricatis,
strobilis ovatis : squamis apice acuniinatis recurvatis margine
niembranaceo-alatis replicatis.
On tlie east coast of New Holland the geographical range of this
species extends from the 14th to the 30th degree of latitude. In the
young state no two plants can be more distinct than this and
A. excelsa, but in the adult state they approach so near that it is
difficult to draw the line of distinction between them.

XVII. Intelligence and Miscellaneous Articles,

ON THE CONSTRUCTION OF OBLIQUE BRIDGES.

The following letter on this subject is extracted from the Newcastle
Journal of November 19th, 1836.

To Peter Nicholson, Esq.
Sir, — IN reference to a lecture stated in the public prints to have
-1 been delivered by Charles Fox, at the Royal Institution, a
few months ago, on what he termed his " new mode of constructing the
Oblique Arch" and stating that "formerly the stones were cut by no
general rule, but merely fitted to their particular place ;" and further,
in regard to what has been published by his desire in the ** Philo-
sophical Magazine" of April last, and, by ** his permission", in
** Loudon's Architectural Magazine" of June last, — I think it an act
of justice to you, and I believe that every person who is acquainted
with the valuable instructions which you have frequently, during a
long course of years, produced for the advancement of science, will
concur in the propriety of setting the public right as to whom the
merit is due, for a proper and certain rule for the construction of the
oblique arch. I therefore deem it right to state, that in your book on
" Masonry and Stone Cutting," published in 1828, there is an elabo-
rate illustration for the working of the spiral or itvist upon the stones;
and the explanation is so clear that Mr. James Hogg, operative ma-
son, residing in Brandling Place, Newcastle, has certi^ed t\\B.t, in
1834, he built an oblique arch entirely from the instructions which
are given in your book ; and so certain did I feel of the practicability of
your rule, that I have adopted it upon the river Coquet, at Felton,
the chord of the arch being 33 feet, and the angle of obliquity 19°,
and in which case the stones were cut, or dressed previously to the erec-
tion of the centre. Having received your approval of the arch as
being in accordance with your design, I think there can be no doubt
that your claim to the rule tor the proper formation of the stones is prior
to that of Mr. Fox ; and I have yet to learn that any rule exists by
which the oblique arch can be so truly built as the one which you
have published. I am not aware, although I have endeavoured to
learn, — and shall be glad, for the sake of the profession of which I have
the honour to be a member, to discover the contrary, — that any of the
oblique arches which have been erected upon any of the public or
private works in the North of England, except those above mentioned,
are constructed upon any general principle j and it is very remarkable,
however much it is to be regretted, that up to the present time there

Intelligence and Miscellaneous Articles. 75

does not appear to have been any proper drawing prepared, nor the
necessary practical instructions given for the certain construction of
the oblique bridges, which have been built upon a very extensive pub-
lic work since 1832 ; but that the contractors were suffered to exer-
cise their own judgement in the erection of them ; and in one case
(decidedly the most important one of the whole,) the entire manage-
ment was, it appears^ left to one of the operative masons in the em-
ploy of the contractor for the building of the bridge. I have been
particular in relating these circumstances, in order to show how little
attention has been ))aid to the proper construction of oblique bridges
hitherto, ivliich require the greatest care, notwithstanding your valuable
work on the subject, as well also to suggest the probability that Mr.
Fox was aware of the want of a general and proper rule in the cases
alluded to, and hence his mistaken notion that " formerly,** that is,
previously to his lecture a few months ago, ** the stones were cut by
no general rule, but merely fitted to their particular place."

I sincerely hope that the inquiry which has be^n set on foot, with
a view to prove that a sure rule for the spiral formation of the stones
has existed for several years, will lead to some advantage, and I am
informed that already, that is, since the commencement of the in-
quiry, the executive engineer of a very extensive public railroad has
very prudently applied to a competent person for a defnite develop,
ment of your principle^ so that m future he may possess a safe guide ;
thus verifying the adage, ** better late than never."

It is too clear that at the present time there is a sort of mania for
oblique bridges. That in many cases, though not so frequently as
they occur, they are indispensable upon railroad lines, but for
turnpike roads, where the rate of travelling rarely reaches 1 I miles
an hour, and considering the absence of lateral friction, now that our
roads are no longer ** gridironed," and the little risk, comparatively;
of departing from the proper course, so great an inconvenience in
railroads, though strikingly disregarded in various situations^ I am
firmly of opinion, after an attentive observation of the practical work-
ing of the best rule, that it is very injudicious to adopt them, except
in cases of absolute necessity. The fact too, that your opinion fully
coincides with the one represented in the Encyclopedia Britannica,
article " Stone Masonry," viz. *Hhat oblique bridges should be avoided
whenever it is possible" is, I submit, a very strong proof of their in-
feriority. I am. Sir, very respectfully.

Your obedient servant,

Hknry Welch,
Surveyor of the County Bridges of Northumberland.
Elswick Villa, Newcastle, Nov. 17, 1 836.

Mr. Fox's paper alluded to above appeared in Lond. and Edinb.
Phil. Mag., vol. viii. p. 299.

OBSERVATIONS ON THE AURORA BOREALIS.

1. Aurora visible at Dublin on Thursday, 29th September, 1836.

The 29th of September last was a cloudy and showery day, but the

L2

76 Inteltigence and Miscellaneous Articles.

sky partially cleared before sunset, and though large patches of rain
cloud hung about, the sun set with a clear red horizon.

The evening was cold ; stars visible j the wind gentle, N. or N.byW.

At 6^ 40"^ a broad diffused light appeared in the northern hemi-
sphere J it gradually became more intense, and at 7^ had lowered its
upper and raised its under edges, and assumed the form of a well-de-
fined arch or segment of a circle. The apparent altitude of the upper
edge was about 30°, and the breadth about 8° or 10°. The eastern
wing bore about N.N.E., and the western about S.E.E., both resting
on the horizon.

The light of the arch was white, and the stars were visible through
it ; there were no clouds in its neighbourhood, nor any waves or al-
terations in the intensity of its light, nor any black band.

At a few minutes past 7 a lofty vertical column of yellowish white
light shot upwards from the horizon, at its eastern side, to the zenith,
where it was lost. Its edges were perfectly straight and exactly de-
fined, particularly the western. It soon became faint from below, and
the upper part resolved itself into a cloudy mass of deep red light, re-
markable for depth and brilliancy of colour, being equal to that of the
richest red stained glass. In a few seconds a similar column rose
about 60° in altitude on the western side, and almost at once became
a broad cloud of rich rosy light, so bright as to appear like the reflec-
tion of a near and great conflagration. Through this, white vertical
streamers several times shot. Towards the zenith the stars appeared
red through it.

The arch now began to depress itself, and the light gradually faded,
first of the two cloudy columns, and of these the eastern first, and
afterwards the arch itself. By 8^ lO'" it had all disappeared and the
night become overcast. By 11^ it had become so clouded that no
stars were visible. There was no other meteor seen.

The altitudes and bearings given are to be considered merely as
approximations, as from the shortness of duration of the aurora and
other circumstances I was enabled to make no instrumental observa-
tions, and my reason for communicating results having such little
pretensions to exactness is to draw attention to the recurrence of red
auroras at this early season, one having been observed at Ryde, as
noticed in the last Number of the Phil. Mag., and another, but of a less
important character, having been visible to night (October 5), at
7^ So"™. It would appear not unimportant to observe the colour of
the sky at sunset, at all times when possible, in connexion with the
colour of auroras, as this might afford some indication how far the
colour was due to atmospheric interference, and possibly give some
indirect clue in solving the question of the altitude of the region of
auroral phaenomena. Robekt Mallet.

Dublin, October, 6, 1836.

2. Aurora observed at Dublin, October 1 1, 1836.

This aurora was different to three others seen this season and the
many observed last winter. Captain Back, in his Journal, describes
and figures one which very much resembled that seen last evening.

Intelligence and Miscellaneous Articles. 77

which was like to the tail of a vast comet. I cannot say when it began,
but I noticed it very strong and distinct on going out of doors ex-
actly at 8 o'clock from Gardiner's Row ; it then appeared to be alto-
gether S. of the zenith. It appeared to begin about 15° S.E. of the
Pleiades, and passing them at about 10° of distance, and thence ex-
tending about 90° N.W. From our zenith its diffused western end
may have been from 30° to 40°. At this place there was a cirro-
stratus cloud, which appeared towards the close of the aurora, about
12 minutes after 8, also to be illuminated. This aurora was appa-
rently narrower at its eastern termination than its west ; it was also
arched ; it had a sensible motion of about 1° per minute S. At 5
minutes past 8 its edges presented that peculiar blackness which has
been noticed by different persons in the Canadian aurora, supposed
to arise from the formation of sensible vapour. This aurora was of
that kind which Capt. Back and Mr. Farquharson, and others, have
noticed as arising from the tops of mountains in masses of cloud. If
some of your correspondents in the south of the city would commu-
nicate their observations, we might, perhaps, be able to trace the lo-
cality of its eastern terminus, and determine its height. Recent ob-
servations lead us to trace the course of aurorae to previous and di-
stant thunder storms. There were appearances of a thunder storm
towards the N.W. yesterday in the afternoon, and at 20 minutes to 5
1 distinctly perceived the reflection of a flash of lightning when
walking in Eccles street. — Oct. 12. E.G. {Saunders's Netos- Letter,
Thursday, Oct. 13,1836.

3. Aurora of October 11 , as observed at Leominster.
To the Editors of the Philosophical Magazine and Journal.

I take leave to send you the following notice of a splendid
and (as it appeared to me) a highly interesting electrical phaeno-
menon, seen here last Tuesday night, the 1 1 th of October, about a
quarter before nine j thinking, as it was visible only for a few mi-
nutes, you might, perhaps, consider it worth inserting in your Jour-
nal. The sky was clear at the time, except on the eastern and
western horizon, where it was obscured by clouds to the height of
about 40°. A broad stream of light, of a pale yellow colour, stretched
across the heavens, passing through the zenith, connecting, like an
immense bridge, the banks of clouds in the east and west. It first
appeared as a band of light streaming in a direct line from the masses
of clouds in the west ; it quickly assumed a waving appearance, form-
ing a variety of graceful curves through nearly the whole extent ; this
lasted about ten minutes, when it became fainter at the eastern end,
and gradually faded away towards the west. In a hw minutes more
it disappeared altogether. — Wm.Gilks.

Leominster, Oct. 1 3. 1 836.

PROCESS OF MAKING CRYSTALLIZED SUGAR FROM TODDY, OR
THE JUICE OF THE COCOA-NUT PALM, ON THE ISLAND OF
CEYLON.

The following notice on this subject was communicated by Lieut.-

78 Jntellis^ence and Miscellaneous Articles,

'b

Colonel Colebrook, Royal Artillery, M.R.A.S., to the Royal Asiatic
Society, and appears in No. Vi. of that Society's Journal.

**The toddy is collected in vessels perfectly clean, into each of which
a small quantity of the al, or banyan-tree, is put to retard fermenta-
tion and correct astringencies. Before the liquor begins to ferment,
it is strained through a clean cloth, and boiled in a pan of brass, or
other metal, until the impurities rise to the surface, when they are
carefully skimmed off. When the liquor has lost its watery colour
and become a little reddish, it is poured into another pan, and boiled
over a strong fire, the scum being again taken off as it accumulates.
The fire is then gradually diminished, until a while scum appears on
the surface and increases to a froth. The liquor then becomes ad-
hesive, and of a consistency to be removed from the fire, which is
ascertained by allowing a little of it to cool, and by drawing it into a
thread between the finger and thumb. If the thread does not break
when drawn to about an inch in length, the syrup is removed from
the fire, poured into another vessel, and left to cool till it is little
more than lukewarm. A little crystallized jagri, or coarse sugar-
candy, is then mixed with it, and the whole is poured into a fresh
vessel, having an aperture and stopple in the bottom, so accommo-
dated as to allow the uncrystallized part to ooze out. Crystallization
is completed in about a week, when the stopple is removed to allow
the remaining fluid to escape, and at the end of another week the
crystallized sugar is taken and placed near a fire in a goni, or sack.
The expense of manufacture is about one penny and one-eighth per
pounds exclusive of the cost of vessels."

PROFESSOR RENWICK ON THE HEIGHT OF THE ROCKY MOUN-
TAINS OF NORTH AMERICA.

We extract the following observations respecting the altitude of
these mountains, hitherto so much underrated, from the Appendix to
Mr. Washington Irving's *' Astoria, or Enterprize beyond the Rocky
Mountains," just published, hoping to draw further attention to the
subject both in Europe and in America.

** Various estimates have been made of the height of the Rocky
Mountains, but it is doubtful whether any have as yet done justice to
their real altitude, which promises to place them only second to the
highest mountains of the known world. Their height has been di-
minished to the eye by the great elevation of the plains from which
they rise. They consist, according to Long, of ridges, knobs, and
peaks, variously disposed. The more elevated parts are covered with
perpetual snows^ which contribute to give them a luminous and, at a
great distance, even a brilliant appearance j whence they derived,
among some of the first discoverers, the name of the Shining Moun-
tains.

" James's Peak has generally been cited as the highest of the
chain ; and its elevation above the common level has been ascer-
tained, by a trigonometrical measurement, to be about eight thou-
sand five hundred feet. Mr. Long, however, judged, from the po-
sition of the snow near the summits of other peaks and ridges at no

Intelligence and Miscellaneous Articles. 79

great distance from it, that they were much higher. Having heard
Professor Kenwick, of New York, express an opinion of the alti-
tude of these mountains far beyond what had usually been ascribed
to them, we applied to him for the authority on which he grounded
his observation, and here subjoin his reply :

"* Columbia College, New York, Feb. 23, 1836.

" * Dear Sir, — In cotr.pliance with your request, 1 have to com-
municate some facts in relation to the heights of the Rocky Moun-
tains, and the sources whence I obtained the information.

" * In conversation with Simon MacGillivray, Esq., a partner of
the North-west Company, he stated to me his impression, that the
mountains in the vicinity of the route pursued by the traders of that
company were nearly as high as the Himalayas. He had himself
crossed by this route, seen the snowy summits of the peaks, and
experienced a degree of cold which required a spirit thermometer
to indicate it. His authority lor the estimate of the heights was a
gentleman who had been employed for several y^ars as surveyor of
that compa^3^ This conversation occurred about sixteen years
since.

" * A year or two afterwards, 1 had the pleasure of dining at
Major Delaheld's, with Mr. Thompson, the gentleman referred to
by Mr. MacGillivray. I inquired of him in relation to the circum-
stances mentioned by Mr. MacGillivray, and he stated that, by the
joint means of the barometer and trigonometric measurement, he
had ascertained the height of one of the peaks to be about twenty-
five thousand feet, and there were others of nearly the same height
in the vicinity. I am, dear Sir, yours truly,

" *To W. Irving, Esq. James Ren wick.' "

METEOROLOGICAL OBSERVATIONS FOR NOVEMBER 1836.

Chiswick. — Nov. 1, Frosty: cold and wet: cloudy. 2. Hazy: drizzly.
3. Cloudy; fine : rain at night. 4. Overcast : rain. 5. Cloudy. 6, 7. Frosty.

8. Sharp frost : clear : frosty with fog at night. 9. Overcast : rain.
10. Cloudy : fine. 1 1. Heavy rain : cloudy and fine. 1 2. Foggy. IS. Rain :
fine : rain at night. 14. Clear and fine. 1 5. Clear and frosty : cloudy.
16. Fine. 17. Overcast : very fine : stormy with rain at night. 18. Fine.
19. Slight frost : rain : stormy showers. 20. Clear. 21. Foggy: drizzly.

22. Foggy : rain. 23. Dense clouds : boisterous : clear at night. 24. Clear
and cold. 25. Frosty : hazy : rain. 26. Foggy : rain. 27. Cloudy.
28, 29. iioisterous with rain. 30. Fine : rain.

[The barometer on the 8th, at 8 a.m., was 30*083, and had risen at an
average of '028 per hour during the night; consequently would he about
30 inches at the time when that along with Mr. Green, in his balloon
ascent, was at 20 inches, or — ^ of the whole atmospheric pressure near the
level ot the sea. — R, Thompson.]

Boston. — Nov. 1 — 3. Cloudy. 4. Fine. 5. Cloudy. 6 — 8. Fine.

9. Cloudy : rain early a.m. 10. Fine : rain early a.m. : rain p.m. 1 1. Cloudy.
12. Foggy. 13. Rain : rain p.m. 14 — 16.Fine: r«in p.m. 17. Cloudy:
rain p.m. 18. Fine: rain p.m. 19. Rain : rain p.m. 20 — 22. Fine -. rain p.m.

23. Stormy : rain early a.m. 24. Fine. 25. Cloudy. 26. Cloudy : rain
early a.m.: rain p.m. 27, 28. Cloudy; rain early a.m. : rain p.m. 29. Rain :
rain early a.m.: rain p.m. 30. Fine: hurricane with rain a.m.

Nov. 28th, about one o'clock p.m., during a heavy thunder storm, Boston
church steeple was struck by lightning, which did considerable damage to
one of the pinnacles, and one of the vanes fell to the ground.

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THE

LONDON AND EDINBURGH
PHILOSOPHICAL MAGAZINE

AND

JOURNAL OF SCIENCE.

♦

[THIRD SERIES.]

FEBRUARY 1837.

(

XVIII. Notice relative to the Publication of the Scientific
Memoirs. By Richard Taylor.

I AVAIL myself of the opportunity which the Philosophical
Magazine affords me, to announce the publication of the
Third Part of the subsidiary work in which I have lately en-
gaged, the Scientific Memoirs, and to appeal for support
and assistance to all those who may be satisfied of the utility
and necessity of such an instrument for furthering the pro-
gress of scientific pursuits in this country, by giving readier
access to the labours of foreign philosophers.

The views with which the work was undertaken were thus
stated in the Advertisement prefixed to the First Part :

" In order to bespeak the favour of the public to this new undertaking,
I shall merely state that the want of such a work has been suggested to
me, during a long connexion with journals of science, by my experience of
the difficulty of giving to the English reader, within the necessary limits
of those works, a sufficient view of the state and progress of the sciences
in other countries. Short abstracts are given, and now and then entire
translations of important memoirs; but original communications, and the
scientific proceedings of our own country, now occupy so great a space in
our journals as to make it impossible to do justice to the researches of
foreigners. Many, indeed, are the valuable memoirs in which these are
recorded, which have furnished subjects for investigation and discussion
among the most distinguished of our countrymen, but which in their en-
tire form have never appeared in English, and can be referred to only in
a small number of public libraries.

*' Projects for supplying this deficiency have been entertained at various
times both by societies and individuals : the scientific journals, also, which
have successively existed have been looked to with this view. But experi-
ence seems to have proved that a regular and full supply of such matter
is not consistent with their plan or limits ; and a considerable increase
of their bulk and cost might reduce the number of purchasers, and
l^hird Series. Vol. 10.- No. 59. Feb.lS^I, M

82 Mr. R. Taylor 071 the Publication

lessen the support which in this country is ah-eady scarcely sufficient to
keep them in existence. I have thought it better therefore to try the ex-
periment of a separate work devoted entirely to the publication of the
more important memoirs and communications, translated from foreign
transactions and journals, to appear at intervals sufficiently distant to
avoid the disadvantage of haste in the execution, and yet frequent enough
to keep pace with the progress of discovery and the wants of the student.

" My present intention is, that the quarterly parts should form an an-
nual volume, which may possess a permanent value, as a depository of
those memoirs in which philosophers of other countries have fully deve-
loped and carefully recorded their views and their discoveries. With re-
gard to the class or arrangement of subjects, I have thought it best not to
confine myself at the outset within any fixed plan of selection ; but to en-
deavour from time to time, with the advice and assistance of men of sci-
ence in our own country, to make it subsidiary to their pursuits, and il-
lustrative of the objects of inquiry which most engage their attention.

" I have been greatly encouraged by the opinions which have been ex-
pressed to me as to the probable usefulness of a work of this kind, as well
as by the valuable suggestions and assistance with which I have been
favoured ; and, should the patronage of the public be sufficient to enable
me to persevere, I may have the satisfaction of making my occupations
conducive to the interests of science."

How far the execution of the design may have hitherto
been generally satisfactory I know not. The approbation and
patronage of many distinguished persons of the highest sci-
entific eminence greatly encourage me to persevere j but,
as yet, the number of purchasers has not been nearly suffi-
cient to defray the cost of publication. I do not hesitate,
therefore, to make an appeal to all who may participate in
the wish for the continuance of the work, trusting that
they will lend their active aid in promoting its success. With
a demand sufficient to cover the expenses, I should determine
to proceed, being more than ever convinced of the need of
such a work, and having made various arrangements for its
improvement.

The following are the Memoirs contained in the First and
Second Part :

M. Melloni, On the Free Transmission of Radiant Heat through different
Solid and Liquid Bodies ;

New Researches relative to the Immediate Transmission of Radiant
Heat through different Solid and Liquid Bodies ; and.

Memoir on the Polarization of Heat. (From the Jnnales de Chimie et
de Physique.)

Prof. H. W. Dove, Experiments on the Circular Polarization of Light ; and,
Description of an Apparatus for exhibiting the Phsenomena of the
Rectilinear, Elliptic andCircular Polarization of Light. (From Poggen-
dorff's Annalen der Physik und Chemip.)

M. NoBiLi, A Memoir on Colours in general, and particularly on a new
Chromatic Scale deduced from Metal lochromy for Scientific and Prac-
tical Purposes. (From the Bihliothhque Universelle des Sciences, &c.)

M. PoissoN, On the Mathematical Theory of Heat. (From the Annales
de Chimie et de Physique.)

M. Savart, Researches on the Elasticity of Bodies which crystallize
regularly. (From the Annales de Chimie et de Physique.)

of the Scientific Memoirs. 83

Prof. LowiG, Experiments on the Essential Oil of the Spircea Ulmaria,
or Meadow Sweet. (From Poggendorff's Annalen.)

Baron Walckenaer, Researches relative to the Insects known to the An-
cients and Moderns by which the Vine is infested, and on the Means
of preventing their Ravages. (From the Annales de la SocUte Entomo-
logique de France.)

Dr. Carus, The Kingdoms of Nature, their Life and Affinity. (From
the Zeitschrift fiir Natur und Heilkunde.)

J. A. Balard, Researches concerning the Nature of the Bleaching Com-
pounds of Chlorine. (From the Annales de Chimie et de Physique.)

E. Lenz, On the Laws of the Conducting Powers of Wires of different
Lengths and Diameters for Electricity. (From the Memoirs of the
Academy of Sciences of St. Petersburg.)

Among the^e it will be seen that the entire series of Mel-
loni's important investigations are now first given to the
English public. In order to render the work useful and in-
teresting, I have been advised to give a preference to subjects
which engage immediate attention in this country. Of this
kind are the labours of M. Becquerel upon the artificial pro-
duction of crystallized minerals by means of voltaic action.
The communications of Mr. Fox and Mr. Crosse at the late
meeting of the British Association at Bristol have excited
much interest upon this subject^ at the time and subsequently.
(See pp. 228 and 537 of o^^i* preceding volume.) What had
been done by Becquerel with regard to it appears^ however,
to have been unknown both to those gentlemen and a great
part of their auditors, the only accounts of his experiments
that had appeared in this country being our short notice in
1830, (Philosophical Magazine and Annals, vol. xii. p. 226,)
and that in Mr. Whewell's Report on Mineralogy. In pre-
paring for publication M. BecquereFs paper I have beei\, fa-
voured with the valuable assistance of Mr. Brooke and Mr.
Golding Bird : and for the highly important Memoir by
Mossotti I am indebted to Prof. Faraday, who kindly com-
municated to me a copy which he had just received from the
author. These occupy a portion of the Third Part; together
with the two entire Memoirs of Ehrenberg on his discoveries
of Fossil Infiisoina, which are just now engaging much of
the attention of naturalists. Two additional papers by Melloni
are now given, in one of which he describes his mode of se-
parating the rays of light from those of heat. The insertion
of Von Wrede's Memoir on the absorption of light was oblig-
ingly suggested to me by Professor Powell.

List of the Memoirs contained in Part III., just published :

M. Clapeyron, On the Motive Power of Heat. (From the Journal de

VEcole Royale Poly technique.)
Dr. BuRMEisTER, On the Sound produced by Insects in Flying. (From

Poggendorff's Aniialen.)
M- Melloni, On the Reflection of Radiant Heat; and.

On the Theory of the Identity of the Agents which produce Light and
Radiant Heat. (From the Annates de Chimie et de Physique.)

M2

84 Mr. Goldhig BircFs Ea:pen menial Researches

M. BioT, On the Constitution of the higher Regions of the Earth's At-
mosphere. (From the Comptes ReJidus des Heanccs de VJcadimie des
Sciences.)

Prof. Ehrenberg, On Fossil Infusoria. — The two Memoirs entire, with
an Engraving of the Figures. (From PoggendorfF's Annalen.)

M. Becquerel, On the artificial production of Crystallized Minerals by
Voltaic action.

Prof. H. Rose, On a New Combination of Anhydrous Sulphuric and Sul-
phurous Acids. (From Poggendorff's Annalen.)

M. MossoTTi, On the Forces which regulate the Internal Constitution of
Bodies. (A Memoir published separately; containing the views re-
specting the identity of origin of gravitation, the attraction of aggre-
gation, and electrical attraction, involving the discovery of the physical
cause of gravitation, which were explained, from this Memoir, by Mr.
Faraday at the first evening meeting of the Royal Institution for the
present season, January 20, 1837.)

M. Pelouze, On certain Combinations of a new Acid, formed of Azote,
Sulphur, and Oxygen. (From the Annales de Chimie et de Physique,)

Baron von Wrede, On the Absorption of Light, according to the Theory
of Undulations. (From PoggendorfF's Annalen.)

My connexions and my profession may afford me, perhaps,
advantages for carrying on the work with a less amount of
support than would be requisite if it were in other hands.
I cannot, however, be expected to incur a considerable loss ;
and I look with confidence to those who approve my attempt
to give me their active aid. If they wish the work to be con-
tinued, they will, I trust, exert themselves to increase the
number of purchasers, which at present is far below what is
absolutely necessary.

I have only to add, that the attention requisite for conduct-
ing this work I shall be happy to give, if its circulation can
be so far extended as barely to pay the cost ; and, though
necessarily it can hardly be of a popular character, this is
not a greater degree of success than may be hoped for, in this
country and its dependencies. Richard Taylor.

XIX. Experimental liesearchcs ofi the Nature and Pro-
perties of Albumen, SfC. By Golding Bird, Esq., F.L.S.,
F.G.S., Lecturer on Experimental Philosophy at Gui/s Ho-
spital,

[Continued fi'oni vol. ix. p. 115, and concluded.]

N the former part of this communication I pointed out the
solubility of albumen after its coagulation by alcohol, &c.,
in water saturated with carbonic acid, as well as the curious
fact of that acid decomposing the alkaline albuminates, causing
the separation and consequent precipitation of the albumen in
an insoluble form, capable of being redissolved by an excess
of the acid. I also mentioned some circumstances connected
with the action of coagulated albumen on the carbonates oi

I

on the Nature and Properties of Albumen^ Sfc,

IT x_ ,.'. ti * ..r :.

^5

soda, and I now propose to continue the account of my investi-
gations in tiiis interesting department of organic cliemistry.

9. From the result of the experiments ah'eady detailed
(7.)j it appeared probable that albumen after its coagulation
by alcohol was capable of partly decomposing the carbonate
and bicarbonate of soda. An interesting inquiry instantly sug-
gested itself as to whether the fluid albumen possessed a si-
milar property. To ascertain how far this was actually the case,
I mixed fresh serum of human blood, freed from fat (l.)? vvith
an equal bulk of a cold solution of carbonate of soda* of
spec. grav. r030. On the addition of the first portion of the
alkaline carbonate, the serum became slightly turbid, which
condition, however, ceased on agitation ; the mixture was then
placed in a flask furnished with a tube bent twice at right
angles and dipping into lime-water; heat was then applied to
the flask and continued until the mixture nearly attained the
boiling-point, when it suddenly swelled up so as nearly to
reach the mouth of the vessel, a torrent of bubbles at the same
instant escaping through the lime-water, which became quite
milky : the lime-water was then removed, and a vessel full of
diluted tincture of litmus substituted; the gas continuing to be
evolved, quickly converted the blue colour of the litmus to
red. This experiment proves most satisfactorily the evolu-
lution of carbonic acid gas by the action of albumen on car-
bonate of soda; and as neither the solution of the alkaline car-
bonate nor of the albumen separately evolved carbonic acid, it
follows as a necessary consequence that the albumen had been
a sufficiently energetic electro-negative element to expel part
of the carbonic acid from the soda and unite with the alkali
thus set free, forming an albuminate of soda. The contents of
the flask were quite transparent after the experiment, and ex-
erted a strong alkaline reaction on turmeric. I may observe
that, after repeating this experiment several times, I constantly
found the evolution of the carbonic acid to occur only when
the mixture had attained the boiling-point, and then to take
place suddenly, and almost immediately cease.

10. Finding that albumen was able to expel par/ of the car-
bonic acid from the carbonate of soda, I attempted, by using
a considerable excess of albumen, to decompose entirely a
small portion of the carbonate ; but in this 1 failed altogether,
the albumen (like some other weakly electro-negative bodies)
having never, under any circumstances which have yet fallen
under my notice, been sufficiently energetic to expel all the
carbonic acid from any given portion of the alkaline carbonate.

11. When the sesquicarbonate or the bicarbonate was

* This solution had been previously boiled for some minutes to decom-
pose any bicarbonate of soda that might have accidentally been present.

86 Mr. Golding BircPs Experiinental Researches

substituted for the neutral carbonate of soda, in the above
experiments, a much more considerable evolution of the acid
gas occurred, as might indeed have been expected a priori.

12. I next repeated the experiment (10. )> substituting for
the carbonate of soda a (previously well-boiled) solution of
carbonate of potash of nearly the same specific gravity, the
bent tube with which the flask was furnished dipping into
lime-water; but not the slightest opacity occurred, even after
the ebullition had been kept up so long as to cause a partial
decomposition of the albumen, evinced by the mixture assum-
ing a deep-brown colour. From the result of this experi-
ment I think it may be fairly deduced, that although albumen
is capable of partly decomposing the carbonate of soda, yet
that it is by no means sufficiently energetic to exert a similar
action on the carbonate of potash.

13. The result of the last experiment tends to throw a
considerable degree of obscurity over the nature of the sol-
vent action exerted by carbonate of potash or albumen, for
that it does exert such an action there can be no doubt, as it
prevents the coagulation of albumen by heat ; for while, in
the case of the solution of albumen in carbonate of soda, we
have sufficient data to prove that part of the carbonic acid
is expelled, and an alkaline albuminate formed ; yet we are
unable to apply a similar explanation to the solution of albu-
men in carbonate of potash, in consequence of our want of
evidence of its possessing sufficient energy to exert even a
partial decomposing action on the latter salt : we have there-
fore only the alternative of supposing that it either forms a
ternary combination with the carbonate of potash, or that it
exists merely dissolved in the alkaline salt without (strictly
speaking) chemical combination.

Action of Electric Currents of different Intensities on Albumen
in its free or combined State.

14. Upon no subject connected with the products of orga-
nization has more discrepancy existed than upon the results
of electric currents on albumen ; one author stating that it is
deposited from its solution at the negative; another, at the
positive electrode; while others, as Raspail {Nouv. Syst. de
Chim. Organ.\ declare that it is coagulated equally at both
electrodes; all, however, agreeing in the excessive delicacy
of an electric current as a test for detecting its presence when
all other means fail. But after investigating this subject with
considerable care, using different intensities of electric action,
solutions of albumen of different degrees of concentration, and
(what I found to be of considerable importance, as influencing
the results,) electrodes of different metals, I feel myself justi-
fied in stating, that the action of electric currents on albumen

on the Nature and Properties of Alhnmen^ Sfc. 87

is constant, and by no means so capricious as has been ima-
gined.

15. Mr. Brande was, I believe, the first who applied electro-
chemical action to the detection of albumen (Phil. Trans.
1809 ; p. 373) ; and from the results of his experiments it ap-
pears, that when a solution of albumen (of white of egir) was
submitted to the action of a battery of 120 four-inch double
plates excited by dilute nitro-muriatic acid, rapid coagulation
took place at the negative, whilst only a thin film of albu-
men appeared at the positive electrode : the same results oc-
cured when a battery of 24- four-inch plates, " highly charged,"
was substituted for the larger one, provided the wires forming
the electrodes were not more than half an inch distant from
each other; for when they were separated to eight inches,
or a smaller battery used, the albumen appeared only at the
positive electrode. When albumen of pus was substituted for
the white of egg, Mr. Brande found coagulation to take place
at both electrodes; but the size of the battery used in this
experiment is not mentioned. Albuminate of soda (procured
by boiling white of egg in water), when submitted to the action
of a battery of 60 four-inch plates, deposited albumen co-
piously at the negative electrode. From the results of his
experiments Mr. Brande appears to have been induced to be-
lieve that albumen, free or combined, always coagulated with
a strong electric current at the negative, and with a weak
current at the positive electrode.

16. To obviate any error that might arise from the heat
evolved by the passage of electric currents of considerable
tension, I determined to employ small plates (2^ inches
square) excited only by weak brine ; these plates were ar-
ranged in separate jars, precisely on the principle of the cou-
ronne des tasscs. Thirty pairs of zinc and copper plates thus
arranged and excited, developed a current sufficiently ener-
getic to decompose water and saline solutions with rapidity,
and communicate a disagreeable shock extending beyond the
wrists ; but failed to heat perceptibly a piece of platina wire
(tito^ of an inch in diameter) sufficiently fine to be readily
ignited by a single voltaic pair presenting 4 square inches of
surface, excited by dilute sulphuric acid.

17. I first examined the action of an electric current on
fluid albumen in as uncombined a state as it can readily be
obtained : for this purpose some dilute and prepared serum of
blood (1.) was placed in a glass cup, and by means of platinum
wires connected with the battery of 30 pairs, excited (as in all
the following experiments unless otherwise expressed) by
weak brine ; in a few minutes a considerable cloudy deposit
occurred in the proximity of the positive electrode, hut mthout

88 Mr. Golding Binrs Experimental Researches

adhering to it. To determine with more accuracy at which
electrode the albumen was really deposited, the experiment
was repeated, with tiw cups containing a solution of albumen,
connected with each other either by means of moistened cot-
ton or asbestos, or, what appears to me to be much more con-
venient, by a glass tube bent twice at right angles and ter-
minating in capillary orifices, filled with water containing just
enough common salt to conduct the current with sufficient
readiness to ensure the success of the experiment. In this form
of the experiment copious coagulation of albumen soon ap-
peared in the positive cup, whilst the fluid in the negative cup
retained its limpidity. On examining the contents of the cups
after the electric action had been continued for six hours, the
fluid in the positive cup was found to be very acid, contained
in diffusion much coagulated albumen, and smelt powerfully of
chlorine, whilst the contents of the negative cup were limpid
and alkaline, and not coagulated by heat; the addition of acetic
or nitric acid, ho vv ever, caused a copious precipitation of albu-
men. The rationale of this result is very simple: the chloride
of sodium (from which it is nearly, if not quite impossible to
free liquid albumen) had been decomposed; chlorine and, from
the subsequent decomposition of the water, hydrochloric acid
appearing in the positive, whilst the soda had been conveyed
to the negative cup, where under electric action it had com-
bined with the albumen, forming an albuminate of soda.

1 8. The last-described experiment was repeated, but with
only 6 pairs of the same plates (16.), similarly excited by weak
brine, and with platinum electrodes : gas was feebly evolved
from both wires, and in about half an hour the contents of the
positive cup were found to be acid, turbid (from the deposi-
tion of albumen), and smelling strongly of chlorine; whilst the
fluid in the negative cup was alkaline, limpid, and contained al-
buminate of soda in solution ; results precisely identical with
those obtained when the larger battery was employed (l?.)*
When copper wires were substituted for platinum in connect-
ing the cups of albumen to the little battery, a singular and
marked difference resulted ; the positive wire became tarnished
from the formation of an oxide, and was almost instantly co-
vered with a film of albumen, which increased so rapidly that
in a few minutes a piece of copper wire 0-02 inch thick be-
came as thick as a crow-quill from the rapid coagulation of
albumen *which adhered strongly to it : this albumen was green,
and contained a considerable quantity of oxide of copper;
affording in its physical and chemical characters a marked
and important difference from that obtained when platinum
electrodes were substituted for copper.

19. Some of the solution of albumen was placed as before

on the Nature and Properties of Albumen, S^c, 89

(17.) "1 two cups, connected by filaments of moistened cotton,
and placed, by means of platinum wires, in communication
with the battery of 30 pairs (16.) in the positive cup, which
I shall call A : a considerable deposit of albumen had appeared,
the contents being acid and smelling of chlorine, whilst the
contents of the negative cup, B, were limpid and alkaline. The
connexion with the battery was now reversed, so that B be-
came the positive, and A the negative cup. In a quarter of
an hour the contents of A were found to be alkaline and
limpid, the albumen that had been deposited having been taken
up, whilst the fluid in B had in its turn become turbid (from,
the coagulation of albumen) acid, and had acquired an odour
of chlorine. The rationale of this interesting experiment is too
obvious to require any explanation.

20. The above experiments having been repeated many
times, and always with the same results, we may safely de-
duce from them the inference, that whenever albumen is
coagulated under electric agency, an acid (hydrochloric ?)
mixed with chlorine is always set free at the positive, whilst
an alkali (soda?) as constantly appears at the negative elec-
trode. Mr. Brande {Op. sup. cit., p. 315 el seq.) arrived at
nearly similar results, differing, however, in this, that he found
the coagulation of albumen to take place almost constantly at
the negative electrode ; on which circumstance, at the sugges-
tion of the late Sir Humphry (then Mr.) Davy, he founded a
theory of the coagulation of albumen. According to Mr. Brande
albumen owes its solubility in water solely to the presence of
soda ; and that in consequence of the separation of this alkali
at the negative electrode, the albumen is there deposited in
an insoluble form. Several and important objections might
be urged against this hypothesis, and amongst others, that
the proportion of soda existing combined with albumen in
white of egg or serous fluids is really so minute that it can
by no means be considered as the solvent body ; moreover, the
albumen of egg or serum coagulates, as is well known, by
heat, which is not the case with the same substance when com-
bined with soda ; added to which, the fact of albumen being
precipitated at the positive electrode by a very weak electric
power, is at once, I conceive, sufficient to demonstrate the un-
tenable nature of the position assumed by Mr. Brande ia
1809, and adopted by later authors.

21. In offering an explanation of the coagulation of un-
combined albumen by electric currents of weak tension, I am
far from presuming that it is altogether unobjectionable ; but
still I think that it explains the circumstance of its coagula-

Third Series, Vol. 10. No. 59. Feb. 1837. N

90 Mr. Golding Bird's Experimental llesearcfics

tion in a manner more consistent with known facts than any
other I have yet met with.

22. I conceive it will be granted by every one at all ac-
quainted with the true nature of electro-chemical decomposi-
tion, that a solution oF albumen free from the minutest trace
of saline or other admixture, would not be affected by a cur-
rent of electricity (premising that all sources of error arising
from the evolution of heat are avoided) of any degree of ten-
sion insufficient for its disintegration and resolution into its
ultimate atoms ; for, like sulphuric acid, soda, or other ions^,
when wicombined it can have no possible tendency to pass to
either electrode ; but when combined with an alkali, and
playing the part of an electro-negative or acid body, and be-
coming an anion, we should expect it to pass to the positive
electrode [aiiode) ; or when acting as a base, becoming a cat-
ion, to pass to the negative electrode [cathode). How then
does an electric current effect the coagulation of albumen ?
Not at all, I believe, by a primary action upon it, but solely
by secondary effects, and in the following manner. Fluid al-
bumen can never be obtained perfectly free from chlorides,
for common salt always exists intimately mixed with it; and
even if this could be entirely removed, still, as Raspail has
shown [Nouv. Syst. de Chim» Org., p. 195), the hydrochlorateof
ammonia is always present. Then on submitting fluid and as
far as we can obtain it, uncombined albumen to voltaic action
(by means of platinum electrodes), the saline matter present
is decomposed, and this consisting chiefly of chlorides of the
alkaline metals, the chlorine' passes to the positive, the bases
to the negative electrodes. As soon as the chlorine is set free
in the positive cup (when two are used, or in the proximity
of the positive electrode when one cup only is employed,) it
precipitates the albumen, a very minute pordon of chlorinef
being sufficient to precipitate a considerable quantity of albu-
men ; whilst the bases in the negative cup combine with the
albumen ; so that at the termination of every experiment of this
kind, chlorine (as indicated by the odour), hydrochloric acid,

• It may not be altogether irrelevant to remind those who may happen
to be not very conversant with the researches of Faraday, that by an ion is
understood a body not itself composed of other ions, and having, when un-
combined, no tendency to pass to either electrode, being quite indifferent
to the passage of the current. Thus iodine, sulphuric acid, chlorine, acetic
acid, soda, ammonia, &c. are ions. [See Lond. and Edinb. Phil. Mag., vol. v.
p. 164.— Edit.]

f Chlorine is undoubtedly the most delicate chemical reagent for the
detection of albumen that we possess, and I may remark that to its pre-
tence nitro-hydrochloric acid owes its value as a test for albumen (5.).

vn I he Nature and Properties of Albumen, S^x. 91

nnd coagulated albumen will be found in the positive, and the
albuminates of soda and ammonia in the negative cup.

But if the communication is made with the battery by
means of copper instead of platinum electrodes, a slight modi-
fication becomes necessary, for another agent comes into play
in assihiting the coagulation of albumen : I refer to the metal
forming the electrodes ; for on completing the connection with
the battery the positive vvii*e oxidizes, and the oxide of copper
in the nascent (?) state combines with the albumen, forming an
insoluble albuminate of copper, which coagulates round the
wire; and thus having two causes operating instead of one
(attraction of the oxide of copper for albumen as well as the
effect of the chlorine), we find the precipitation of albumen to
take place far more speedily and in much larger quantity when
copper is used instead of platinum to connect the albuminous
solution with the battery; and acting on this principle, when-
ever I have merely the detection of albumen in view, I am ac-
customed to use electrodes of clean copper v\'ire, connected with
a little battery of 5 or 6 pairs of plates (18.) excited only by
weak brine, which I find to be amply sufficient for the pur-
pose. But whatever may be the intensity of the electric cur-
rents, or whatever the metal forming the electrodes, we have a
sufficient number of facts to believe that free albumen is never
precipitated by the electric current itself^ but by its effects in
setting free chlorine, or determining the formation of an oxide
for which albumen has considerable affinity.

23. It may now be asked, why in Mr. Brande's experi-
ments (Phil. Trans, siip. citat.) the coagulation of albumen?
took place as constantly at the negative, as in mine at the po-
sitive electrode. To this question a ready solution may be af-
forded, when we recollect that in Mr. Brande's experiments
the batteries employed were large, and excited by strong acids,
whereby the electric currents developed were in a state of
considerable tension ; in consequence of which, the albumen,,
rendered insoluble by the presence of chlorine at the positive
electrode, was mechanically conveyed by the current of positive
electricity towards the negative side of the battery. That the
passage of electricity is capable of exciting currents in liquid
conductors of apparenlhj considerable mechanical intensity
the expel iments of Sir John Herschel (Phil. Trans. 1821-,
p. 162,) are more than sufficient to demonstrate; whilst the
fact of such currents being sufficiently energetic to transfer
minutely divided solids from the positive tovvart^s the negative
electrode, even when in separate tubes, has been proved by
M. Becquerel, (Traite de V Electricite, tom. iii. p. 102,) wha
observed finely divided clay to be actually driven by the

N2

92 On the Mature and Properties of Albumen ^ Sfc.

mechanical power of sncli currents, excited in liquid con-
ductors by the passage of electricity, out of the positive tube ;
and hence by diminishing ihe tension of the electricity deve-
loped (as in my experiments), such transfers may be pre-
vented and the coagulated albumen constantly collected in
the positive cup.

24. I was next desirous to examine the effects of electric
currents on an alkaline albuminate. In this combination the
albumen acts as a tolerably energetic electro-negative element,
and might consequently be expected to be coagulated at the
positive electrode. To determine this, some albuminate of
soda was prepared as perfectly neutral as possible (2.), diluted
with water, and placed in two glass cups communicating by a
bent tube filled with the same fluid ; the cups were connected
with the battery ofSO pairs of plates (16.) by means of platinum
wires: a copious and rapid coagulation ensued in the positive
cup as was expected. In this case the deposition of albumen
can very fairly be attributed to the action of the electric cur-
rent ; for being combined with a cation (soda) it must neces-
sarily act as an a?iiofi, and hence like all anions be deposited
at the positive electrode {anode), A very weak current, as
that afforded by 5 or 6 pairs of plates, is sufficient to produce
this effect. When copper wire is substituted for platina in
the formation of the electrodes, the decomposition takes place
with equal rapidity, the albumen being deposited round the
positive wire in the form of fine almost diaphanous tubes
(more resembling organized membrane than anything else),
which drop from the wire almost as soon as formed, and are
nearly, if not quite free from copper ; affording a striking con-
trast to the irregular, massive, green, precipitation of albumen
ad/ie7'i?ig to the copper electrode when uncombined albumen
is the subject of experiment.

25. Electrolytic action did not yield equally satisfactory re-
sults when combinations of albumen with acids were employed,
for the evolution of chlorine (which it is next to impossible to
avoid) almost always caused the precipitation of albumen in
the positive cup ; and although I sometimes succeeded in caus-
ing the albumen to coagulate in the negative cup, yet it was
never sufliciently constant to authorize any opinion on the
basic nature of albumen. Subsequently, however, I succeeded
in obtaining more satisfactory results, by avoiding the influence
of chlorine on albumen in the positive cup : for this purpose
I took two glass cups connected by filaments of cotton moist-
ened with brine, and filled one v;ith water (containing just
enough common salt to render it sufficiently conducting), which
1 connected by a platinum wire with the positive, the other

On the ActioJi of Voltaic Electricity on Iodic Acid, 93

with acetate of albumen, which was connected in a similar
manner to the negative side of the battery of 30 pairs* {16.).
In an hour a considerable cloud of albumen had appeared in
the negative cup; the fluid in the positive was, of course, acid :
to this an excess of caustic soda was added, and the whole
evaporated to dryness: on the addition of sulphuric acid to
the dry residue, an odour of acetic acid was evolved. This
proves, I conceive, that albumen may play the part of an
electro-negative body ; for whatever objections may be urged
against my deductions from this experiment, no one, 1 pre-
sume, would imagine acetic acid to be conveyed to the posi-
tive cup, unless it was combined as an anio?t with some basic
body, which in this case could be nothing but albumen. I must
confess, however, that albumen forms much more perfect com-
binations with bases than with acids, and appears to be more
allied to the electro-negative than to the electro-positive bodies,
in this respect bearing to the other products of organization
a similar relation to that of silica to the inorganic bodies.
44, Seymour-street, Euston-square.

XX. On the Action of Voltaic Electricity on Iodic Acid, By
Arthur Connell, Esq.^ F.R.S.E.

To the Editors of the Philosophical Magazine and Journal,

Gentlemen,
TN your Number for May 1836, (vol. viii. p. 401) I observe
^ a passage in a paper by Mr. E. Solly stating that iodic
acid which had been freed from water by keeping it in fusion
for a short time, during which one half of it was decomposed
by the heat, was found to conduct electricity extremely well
whilst in its fused state, but that as the points of fusion and
decomposition of this substance by heat are the same, it was
impossible to ascertain whether it was decomposed by the
electric current or not, although the ebullition was thought
to be thus increased; and further, that a solution of iodic acid
is an electric conductor, iodine appearing at the negative
pole.

From the bearing of these experiments on several interest-
ing points of electro-chemistry, particularly on the supposed
connection between atomic constitution and susceptibility of
voltaic decomposition, I do not feel inclined to concede to
any one the priority in making and in publishing them, al-

* I find 12 pairs of plates to be quite sufficient for the success of this
experiment, providing that a longer time (4 or 5 hours} is allowed.

9l< Mr. Connell on eledrolyzing Iodic Acid.

ihou^^li of course always extremely liappy to find the results
obtained by others coincide with my own. In a memoir
*' Oil the action of voltaic electricity on alcohol, aether, and
aqueous substances," read to the Royal Society of Edinburgh
in April 183.5, and printed and distributed in May of that
year amongst various individuals and societies in London
and elsewhere, several principles of voltaic decomposition
were examined, and amongst others the supposed general
law, that electrolytes are composed of a like number of atoms
of their constituent elements; and I ventured to state my
doubts as to the universality of the application of that law;
and as one argument in support of these doubts, 1 quoted the
very experiment above set forth on fused iodic acid. After
showing (printed Mem., p. 24.) by means of the volta-elec-
trometer that iodic acid in solution is not directly decom-
posed by voltaic agency, but that oxygen is liberated at the
positive pole in the same definite proportion as from the elec-
tric decomposition of water by the same current, whilst iodine
separates at the negative pole in virtue of the secondary ac-
tion of nascent hydrogen, 1 observed, p. 26, that it was doubt-
ful whether " iodic acid, although it resists decomposition in
solution, may not give way in the dry and fused state." After-
wards, p. 35, comes the experiment itself on the fused acid
in the following words: "1 made some experiments on dty
and fused iodic acid, which, from the slight aflinity of its
constituents, I thought likely to throw light on the subject*
A difficulty, however, presented itself, arising from the cir-
cumstance that when completely freed from water its points
of fusion and decomposition are extremely near one another.
I Ueed it from water by keeping it in a fused state in a tube
for a considerable time after a portion of the acid was decom-
posed, and until water was no longer evolved. The residue
was dry and hard, and was immediately transferred to a long
and bent narrow tube ; where platinum wires connected with
the two ends of a battery of .50 pairs of 2-inch plates were
brought into contact with it, the before-mentioned galvano-
meter being also introduced into the circuit. The iodic acid
was then heated to fusion by a spirit-lamp, when immediately
a considerable, and even permanent deflection of the needle
took place. Although it was thus quite manifest that a cur-
rent passed, it was impossible for me to say with certainty
tliat the acid was decomposed by the voltaic agency, because
the heat applied was itself sufficient to cause decomposition
and volatilization of iodine on both sides."

Although I still think that this experiment ought to be
viewed with the caution expressed in the above passage, I do

Solvent Action of Muriate and Nitrate of Aminotiia, 95

not feel less inclined now, than when I made and published
it, to regard it as unfavourable to the exi^tence of the sup-
posed general law. The differences between this experiment
and that of Dr. Faraday on fused periodide of mercury, are,
that in the latter the conduction is stated to be feeble, and no
signs of decomposition are visible ; whilst in the former the
conduction is so marked as to impress the mind with the idea
that decomposition by the electric current is going forward.
The signs of decomposition are obvious, although undoubt-
edly in part at least due to heat ; and the relative number
of the constituent atoms of the substance acted upon are much
more unequal. Various other considerations are hostile to
the general law referred to, some of which are stated in the
above memoir*.

In the hope that you may find a corner for the preceding
observations, I remain, Gentlemen,

Your very faithful Servant,
Edinburgh, Nov. 28, 1836. Arthur Connell.

XXI. On the Solubility of certain Metallic Oxides and Salts
in Muriate and Nitrate of Ammonia, By R. H. Brett,
Esq., F.L.S4

TJpROM a notice contained in the Supplement to the Decem-
■- ber Number of the Philosophical Magazine, (vol. ix. p. 540),
of some experiments of M. Vogel on the solubility of the earthy
carbonates in muriate of ammonia, corroborated by some expe-
riments on that subject performed by Mr. J. D. Smith, I have
been induced to extend the inquiry, for the purpose of ascer-
taining whether the same salt, as well as the nitrate of ammo-
nia, exerted any solvent action over certain earthy and alkaline
salts, which are either insoluble or very sparingly soluble in
water, and how far this solvent power extended to the metallic
oxides (more ordinarily met with) and their salts insoluble in
water. The following are the results :

Salts of Lime. — 1. The carbonate and phosphate readily
dissolve in cold solutions of the muriate of ammonia as well
as the nitrate, the earthy salts being recently precipitated.

* The volume of the Edinburgh Transactions to which the above me-
moir belongs has only now come out, but besides the above-mentioned
distribution of the printed memoir, the Society's abstract of the paper re-
ferred to was published a year and a half ago, and in it the experiment on
fused iodic acid is particularly described. A different abstract appeared in
Professor Jameson's Journal (July 1835), in which the other topics of the
paper were treated at greater length, whilst those above referred to were
for the sake of brevity omitted.

t Communicated by the Author.

96 Mr. Brett on the Solubility of certain Metallic Oxides

2. The recently precipitated sulphate dissolves even in the
cold, less speedily, however, and perhaps less completely than
the carbonate or phosphate.

3. The borate and tartrate dissolve even in the cold.

4. The oxalate does not appear to dissolve either in the
hot or cold solution.

The nitrate of ammonia acts much in the same way as the
muriate, and a portion of these calcareous salts is retained in
the solution of the ammoniacal salts, even after the fluid has
been at rest for some time.

Barytic Salts. — 1. The carbonate, phosphate, and oxalate
undergo solution in a cold solution of muriate of ammonia.

2. The sulphate does not dissolve.

5. The borate and tartrate undergo solution in the cold
salt. A solution of nitrate of ammonia appears to dissolve less
of the phosphate of baryta than the muriate of ammonia: it
acts much in the same way towards the other barytic salts.

Strontian Salts. — 1. The carbonate and phosphate are easily
dissolved in a cold solution of muriate of ammonia.

2. The oxalate dissolves in a hot solution of the ammonia-
cal salt.

3. The sulphate does not undergo solution.

4. The borate and tartrate readily dissolve.

The solution of nitrate of ammonia appears to exert a
greater solvent action over the oxalate of strontia than the
muriate of ammonia does; in other respects it does not differ
from the latter salt.

Magnesi an Salts. — 1. The phosphate of magnesia and am-
moniaco-magnesian phosphate dissolve in a hot solution of
muriate of ammonia.

2. The carbonate and tartrate dissolve in a solution of
muriate of ammonia.

The nitrate of ammonia appears to exert a less energetic
solvent action than the muriate.

Salts of Lead. — 1. Carbonate of lead is dissolved in muriate
of ammonia, especially when the solution of the ammoniacal
salt is heated : when the carbonate is in small quantity it is
dissolved without heat.

2. The oxide of the same metal is also dissolved, but it re-
quires a longer continuance of the heal.

3. The sulphate when in small quantity is dissolved with-
out heat.

4. The oxalate is dissolved, especially in the warm ammo-
niacal salt.

5. The tartrate and phosphate are dissolved in the cold so-
lution.

071(1 Salts in Muriate and Nitrate of Ammonia. 97

6. The ferro-cyanate and chromate are not dissolved.

7. The iodide is dissolved even in the cold.

Salts of Zinc. — 1. The carbonate is dissolved even in a cold
solution of nuiriate of ammonia.

2. The phosphate undergoes solution in the hot salt, as
does also the oxide.

3. The oxalate is soluble in a hot solution of muriate of
ammonia.

4. The ferro-cyanate of zinc does not appear to dissolve.
The nitrate of ammonia is a somewhat less perfect solvent

than the muriate.

Per-salts of Mercury. — 1. The oxide is dissolved by a so-
lution of muriate of ammonia, especially when heat is applied.

2. The triple salt produced by adding ammonia to a per-
salt of mercury is dissolved in the hot solution of the an mo-
niacat salt.

3. The carbonate is dissolved by a hot solution of muriate
of ammonia.

4. The phosphate and oxalate are dissolved in the cold so-
lution of the ammoniacal salt.

5. The period ide is speedily dissolved in a lukewarm so-
la tion of muriate of ammonia.

6. The chromate is dissolved in the warm solution.

The nitrate of ammonia acts in the same way as the muriate.
Proto-salts of Mercury. — 1. The sub-proto-nitrate does not
appear to undergo solution.

2. The black oxide undergoes solution.

3. The chloride, iodide, carbonate, phosphate, and tartrate
dissolve in hot or warm muriate of ammonia, less completely,
however, than the persalts.

Nitrate of ammonia is not so good a solvent as the muriate.

Proto-salts of Iron. — 1. Neither the oxide, carbonate, phos-
phate, nor prussiate seems to undergo solution in muriate of
ammonia or in the nitrate.

Per-salts of Iron. — 1. The peroxide and its salts are si-
milarly situated with the protosalts.

Salts of Antimony. — 1. The protoxide dissolves in a cold
solution of muriate of ammonia.

2. The carbonate dissolves in the hot solution.

3. The prussiate does not appear to suffer solution. The
nitrate of ammonia acts in the same way as the muriate.

Salts of Silver. — 1. Chloride of silver readily tlissolvcs in hot
muriate of ammonia, from which solution muriatic acid does
not throw it down.

2. The carbonate undergoes solution in the hot salt.

3. The phosphate and oxalate undergo solution.
Third Series. Vol. 10. No. 59. Feb. 1837. O

98 Mr. Brett an the Solnhililt/ of certain Metallic Oxides

4. The prussiate does not appear to undergo solution.

Nitrate of ammonia acts as a veiy imperfect solvent of the
above salts.

VrotO' salts of Tin. — 1. The oxide appears to be only spar-
ingly soluble in the hot as well as cold solution of muriate of
ammonia.

2. The phosphate and prussiate do not appear to dissolve.

3. The oxalate dissolves readily in a warm solution of mu-
riate of ammonia.

The nitrate of ammonia appears to exert a solvent action
only on the oxalate.

Fey- salts of Tin. — 1. Do not appear to undergo solution
readily, if at all, either in the muriate or nitrate of ammonia.

Salts of Bismuth. — 1. The oxide and carbonate undergo
solution in muriate of ammonia.

2. The phosphate and subnitrate readily dissolve.

The nitrate of ammonia exerts no appreciable solvent ac-
tion over the above bismuthic salts.

Per-salts of Copper. — 1. The oxide dissolves, as does also
the carbonate, forming a fine deep-blue-coloured solution ; if,
however, the latter be acid, or heat be applied, a green-co-
loured solution of the chloride or subchloride is formed.

2. The phosphate, oxalate, and prussiate do not dissolve.

Nitrate of ammonia does not dissolve the last three salts; it
dissolves, however, the oxide and carbonate.

Salts of Manganese, — 1. The oxide readily dissolves even
in a cold solution of muriate of ammonia; not so the car-
bonate. When the solution of the oxide is heated it is not
precipitated.

2. The phosphate is dissolved in the cold salt, but throws
down a portion.

3. The prussiate is not dissolved.

The nitrate of ammonia dissolves the oxide in the cold, not
so the carbonate. The phosphate is partially dissolved ; heat
however, causing it to come down again.

Salts of Cobalt. — 1. The oxide is dissolved, even in a cold
solution of muriate of ammonia, forming a pink solution; if,
however the blue and hydra ted oxide of cobalt be heated pre-
viously to the addition of muriate of ammonia, so as partially
to convert it into a brown colour, the ammoniacal salt does
not dissolve the brown portion of oxide.

2. The carbonate is dissolved even in the cold.

3. The phosphate undergoes a less perfect solution, and the
prussiate does not dissolve.

If prussiate of potash, which produces a green precipitate
in salts of cobalt, be added to a solution of such salts in mu-

and Salts in Muriate and Nitrate of Ammonia, 99

riate of ammonia, a yellowish brown- coloured precipitate en-
sues. The nitrate of ammonia acts much in the same way
as the muriate.

Salts of Cadmium.— \, The oxide and carbonate dissolve
in a cold solution of muriate of ammonia.

2. The phosphate and oxalate also dissolve in tlie cold fluid.

'6. The prussiate does not undergo solution.

The nitrate of ammonia is a less perfect solvent of the salts
of cadmium than the muriate.

Salts of Platinum.-^\, The triple compound, chloride of
platinum and potassium, is soluble in muriate of ammonia, as
is also the chloride of platinum and ammonia.

None of the sulphurets of the preceding metals undergo so-
Jution in muriate or nitrate of ammonia. In all the experi-
ments the ammoniacal salts were added to the recently preci-
pitated oxides and salts. The solution of phosphate of lime
in muriate of ammonia may, hov^'ever, be nearly if not entirely
precipitated by an excess of caustic ammonia: if, on the con-
trary-, only a small quantity of the caustic alkali be added,
although a slight precipitate v^'ill take place and the fluid be
slightly alkaline, still when filtered it will be found to contain
lime by the addition of oxalate of ammonia. In the analysis,
therefore, of a solution in muriatic acid supposed to contain
phosphate and carbonate of lime, if sufficient ammonia be not
added over and above that which is necessary to render the
fluid somewhat alkaline, the filtered solution will be precipi-
tated by oxalate of ammonia, and might lead to the supposition
that carbonate of lime was present: if even an excess of ammo-
nia had been employed and the fluid heated, the same source of
fallacy would exist, because the excess of ammonia would have
been driven off, and the resulting fluid would contain phos-
phate of lime in solution; the same applies to the phosphate
of baryta and strontia, also to the phosphate of magnesia.

The salts of lead which are soluble in muriate of ammonia,
are precipitated from that solution by an excess of caustic am-
monia : hence in precipitating solutions of lead by sulphuric
or oxalic acid, where an ammoniacal salt exists, care should be
taken that the fluid be strongly alkaline, so as to counteract
the solvent power of the ammoniacal salt; the presence of
lead in such solutions would, however, be readily detected by
sulphuretted hydrogen or hydro-sulphuret of ammonia. The
fact of the oxides of iron not being soluble in muriate of am-
monia might afford a means of separating them from several
other metallic oxides with which they are frequently united,
more particularly the peroxide: by this means the latter might
be separated from lead, mercury, antimonv, zinc, bibniuth^

02

100 Mr. Black Willi on a new Genus and

copper, nianpraiiese. In certain cases, however, tliis would not
be convenient unless the quantity of the above metals was in-
considerable. The oxides of manganese and cobalt, from their
ready solubility, might easily be thus separated from iron.

R. H. Brktt.

XXII. Characters of a new Germs and some undescribed Species
tj/'AraneidoB. Bi/ John Blackwall, Esq., F.L.S., t^c*

Tribe, Inequitelje, Latreille.
Genus, Deletrijc.

EYES six in nuniber, unequal in size, aggregated in pairs on the anterior
I part of the cej)halothorax'; two pairs are phiced laterally, their an-
terior eyes being the largest, and their posterior ones the sujaliest of the
six; the third pair is intermediate, the eyes which constitute it being oval,
and contiguous ; the entire group f^rms two triangles united by the apices
composed of the oval-shaped eyes.

MaxilUe enlarged at the base, externally, where the palpi are inserted,
and slightly so at the extremity ; inclined towards the lip.

Jjip short, triangular, and pointed.

Legs long, and moderately robust; the fourth pair is the longest, then
the first, which a little exceeds the second in length, the third pair is
the shortest. Tarsi triarticulate, the terminal joint being very short and
slender.

Deletrix exilis.

This minute spider has the cephalothorax oval, glossy, convex, pointed
before, abruptly sloping behind. Mandibles slender, conical, vertical.
Pectus broad, heart-shaped, convex, provided with some scattered hairs.
These parts, with the n)axillas and lip, are pale red. Legs supplied with
liairs, and with two rows of spines on the inferior surface of the tibiae and
tarsi, directed down the joints, those on the first and second pairs being the
inost conspicuous ; they are of a pale yellowish brown colour, the thighs
liaving a tinge of red. The palpi resemble the legs in colour, and are
abundantly supplied with long hairs, particularly at the extremity. Tarsi
triarticulate ; the terminal joint, which is very short and slender, has two
curved, pectinated claws at its extremity, and a small brush beneath then).
Abdomen oval, thinly covered with hair, projecting over the base of the ce-
f)halothorax ; its colour is yellowish brown, wi(h a band extending along
each side of the medial line on the upper part, some irregular, oblique stripes
on the sides, and a longitudinal band occupying the middle of the under
part, of a browner hue. Plates of the spiracles pale yellow. Spinning mani-
niulai prominent, and of a pale yellowish white colour.

Length, from the anterior part of the cephalothorax to the extremity of
the abdomen, -rV^h of an inch ; length of the cephalothorax ;,'^; breadth
■^r ; breadth of the abdomen 3V; length of a posterior leg-^V; length of
a leg of the third pair -tt.

All the specimens of this spider which I have captured were females,
Hiid were discovered under stones and blocks of wood, at Crumpsall Hall, in
September, 1836. Being ignorant of the oeconoujy of the species, I have
placed it, i)rovisionally, in the tribe hiequitdce, as it bears a close resem-
bbmce to the spiders belonging to the genus Sci/todes in the structure of
the mouth.

• Communicated by the Author.

some undescribed Species o/'Araneidse. 101

Genus, Theridion, Walckenaer.

Theridionformosum .

Cephalothorax oval, convex, glossy, with a large indentation in the
medial line of the posterior region; its colour is yellowish brown tinged
with green, a broad black band extending along the n)iddle, and a fine
line of the same hue occurring on the margins. Mandibles conical, verti-
cal, armed with a few teeth on the inner surface, near the extremity.
Maxillaj inclined towards the lip, obliquely truncated at the extremity, on
the outer side. These parts are of a reddish brown colour, the lip, which
is nearly semicircular, being black at the base. Pectus heart-shaped, with
small prominences on the sides, opposite the legs; it is yellowish brown in
the middle, and has broad, black, lateral margins, which n)eet at the point.
Legs long, provided with hairs, of a yellowish brown colour, with reddish
brown bands; the firbt pair is the longest, then the fourth, which is a very
little longer than the second, the third pair being the shortest. Each tarsus
is terminated by three claws ; the two superior ones are curved and pec-
tinated, and the inferior one is inflected near its base. The palpi resemble
the legs in colour, and have a curved, pectinated claw at the extremity.
Eyes nearly equal in size ; four, which are intermediate, form a square,
the other four are disposed in pairs on the sides of the square, the eyes
constituting each pair being placed on a small eminence, and contiguous.
Abdomen oval, convex above, projecting greatly over the base of the ce-
phalothorax, thinly covered with hair; along the' middle of the upper |)art
extends a broad, dentated, dark red-brown band, bordered anteriorly with
I)ale yellow ; the colour of the sides is a lighter shade of red-brown ; the
under part is yellow, with a tinge of green, a broad, longitudinal, dark red-
brown band occupying the medial line. A small, pale, curved, prominent
process is connected with the sexual organs. Plates of the spiracles yellow.

licngth, from the anterior part of ihc cephalothorax to the extremity of
the abdomen, ^th of an inch; length of the cephalothorax -rV 5 breadth
^'-r; breadth of the abdomen tVj length of an anterior leg-g-V; length of
a leg of the third pair J.

The male is rather smaller than the female, which it closely resembles in
colour ; the absolute length of its legs, however, is greater, an anterior one
measuring ^ths of an inch ; their relative length also is different, the se-
cond pair being longer than the fourth. The third and fourth joints of
the palpi are short; the latter, which is the stronger, projects an acute
apophysis from the lower extremity, underneath, and has a protuberance
on the outer side, from which proceed several long bristles; the fifth joint
is of an oblong oval shape, convex and hairy externally, concave within,
comprising the palpal organs ; they are moderately developed, compli-
cated in structure, having an obtuse projecting process in contact with the
protuberance on the outer side of the fourth joint, and two fine spines at
the lower extremity, one of which is curved into a circular form ; their co-
lour is dark reddish brown. The terminal joints of the palpi have their
convex sides directed towards each other.

I discovered this spider on rails and gates, at Oakland, in June, 1836.
The structure of its snare is similar to that of the snares of the other
species of Theridia.

Tribe ^ Orbitel^, Latreille.

Genus, Epeira^ Walckenaer.

Ejpcira niibila,

Cephalothorax of the male inversely heart shaped, convex, glossy, with
a large indentation in the medial line of the [jostcrior region ; its colour

102 Mr. Black wall on a new Genus and

is yellowish brown, with a broad band of brownish black, whose margins
are the darkest, extenJing along the middle. Mandibles conical and ver-
tical. The maxillaR incline towards the lip, which is semicircular, and
appear to be somewhat pointed, being obliquely truncated at the extre-
mity. These parts are of a pale reddish brown colour. Pectus heart-
shaped, of a yellowish brown hue. Eyes nearly equal in size; four, which
are intermediate, form a square, the two anterior ones being placed on a
projection of the ceplialothorax ; the other four are disposed in pairs
on the sides of the square, the eyes constituting each pair being contiguous,
and placed on a tubercle. Legs moderately robust, clad with hair, of a yel-
lowish brown colour ; the first pair is the longest, then the second, the third
pair being the shortest. The two superior tarsal claws are curved, and
pectinated, and the inferior one is inflected near its base. The palpi re-
semble the legs in colotir, with the exception of the terminal joint, which
is dark brown; the third and fourth joints are short, and strong, the latter
being most pronunent on the outer side ; the fifth is oval, convex, and
hairy externally, concave within, coniprising the palpal organs, which are
highly developed, and are provided, on the outer side, with a strong spine
ciu'ved into a circular form, and terminating in an obtuse projection at
their lower extremity ; they are of a dark red-brown colour. The ter-
minal joints of the p.ilpi have their convex sides directed towards each
other. Abdomen oval, convex above, thinly covered with hair, projecting
over tlie base of the cephalotliorax ; the upper part is brownish black ;
the sides and under part are pale yellow, the former being almost white at
their anterior part, near the ceplialothorax. The plates of the spiracles
are yellow, and eacli is surrounded by an irregular black line.

Length, from the anterior part of the cephalothorax to the extremity of
the abdomen, ^^th of an inch; length of the cephalothorax -jVJ breadth
aV ; breadth of the abdomen Vt i length of an anterior Isg^; length of
a leg of the third pair Vs .

I discovered males of this species on rails and gates, at Oakland, in June,
1836.

Tribe, LATKRiGRADiE, Latfeille.
Genus, Philodromiis^ Walckenaer.

Philodromus variatus.

Ceplialothorax broad, convex, hairy, inversely heart-shaped, with a mi-
nute indentation in the medial line of the posterior region; sides dark-
brown mingled with yellow-brown, a broad band of the latter hue extend-
ing along the middle. Mandibles moderately strong, conical, vertical,
armed with one or two small teeth on the inner surface, of a reddish
brown colour. Maxillae yellowish brown, gibbous underneath, at the base,
inclined towards the lip, which is triangular, rounded at the tip, and of a
dark-brown colour, being palest at the apex. Pectus heart-shaped, thinly
covered with whitish hairs, of a yellowish brown colour, with reddish
brown lateral margins. Legs long, slender, provided with hairs and sessile
spines, of a pale reddish brown hue, which is deepest at the joints; the
second pair is consideral)ly the longest, then the first, the third pair being
slightly longer than the fourth. Each tarsus is terminated by two curved,
pectinated claws, beneath which is a small brush. The palj)i resemble the
legs in colour, and have a curved, pectinated claw at their extremity. Eyes
disposed in two transverse, curved rows, in the form of a crescent, on the
anterior part of the cephalothorax; the anterior row is much the shorter,
and the lateral eyes of the posterior row, which are seated on a small emi-
uence, are the largest of the eight. Abdomen oval, hairy, convex above.

some undescribed Species of ArawMss. lOS

projecting a little over the base of the cephalothorax ; its colour is yellow-
brown, mingled with red-brown, and very dark brown ; a band of the latter
hue extends from the anterior part, along the middle, nearly half its length ;
this band is comprised between two parallel bands of pale yellow-brown,
and on each side of it are two sunken spots of very dark brown, forming,
together, a small quadrangle ; about the middle, several oblique, very dark
brown patches occur, behind which is a curved, transverse line of the same
tint; a black streak passes upwards from each spinning mammula of the
superior pair, the space between them being of a glossy yellow-brown co-
lour ; the sides are red-brown blended with brownish black ; the under
part is yellowish white faintly tinged with dull green, a large, longitudinal
band of very dark brown occupying the middle. The plates of the spi-
racles are dull yellow.

Length, from the anterior part of the cephalothorax to the extremity of
the abdomen, ^th of an inch; length of the cephalothorax -rV; breadth
tV; breadth of the abdomen^; length of a leg of the second pair -^;
length of a leg of the fourth pair ■^.

J found the female of this species on rails, at Oakland, in August, 1836.

Philodromus mistus.
Cephalothorax broad, convex, hairy, inversely heart-shaped, with a mi-
nute indentation in the medial line of the posterior region ; it is of a yel-
lowish brown colour, having a broad, longitudinal, dark brown band on
each side, and narrow, pale yellowish white margins. Mandibles mode-
rately strong, conical, vertical, armed with one or two very small teeth on
the inner surface. Maxillae powerful, enlarged externally, where the palpi
are inserted, very gibbous underneath, at the base, and greatly inclined
towards the lip, which they encompass. These organs are of a yellowish
brown colour, with the exception of the lip, which is triangular, rounded
at the tip, and dark brown at the base, the apex only being yellowish
brown. Pectus heart-shaped, thinly covered with whitish hairs, of a yel-
lowish brown colour, freckled with minute, blackish spots, which are densest
on the sides. Legs long, slender, provided with hairs and sessile spines,
of a pale yellowish brown colour, interspersed with minute blackish spots,
which are scarcely perceptible without the aid of a magnifier; the second

{)air is considerably the longest, then the first, the third pair being slightly
onger than the fourth. Each tarsus is terminated by two curved, deeply
pectinated claws, beneath which is a small brush. The palpi resemble the
legs in colour, and have a curved, pectinated claw at their extremity. Eyes
disposed in two transverse curved rows, in the form of a crescent, on the
anterior part of the cephalothorax; the anterior row is much the shorter,
and the lateral eyes of the posterior row, which are seated on a small emi-
nence, are the largest of the eight. Abdomen oval, hairy, convex above,
projecting a little over the base of the cephalothorax ; the upper part is of
a pale yellowish brown colour, mottled with reddish brown, an obscure ob-
long oval band of the latter hue extending from the anterior extremity,
along the middle, nearly half its length; it is surrounded by an irregular
band of dark reddish brown, from which some imperfectly defined streaks
pass obliquely upwards, particularly in the posterior region ; the sides and
under part are dull yellow-white, minutely spotted with reddish brown,
three longitudinal bands of red-brown extending along the middle, and
meeting in a point near the spinners. Sexual organs of a very dark red-
dish brown colour. Plates of the spiracles dull yellow, or yellowish brown.

Length, from the anterior part of the cephalothorax to the extremity of
the abdomen, ^j^^ths of an inch ; length of the cephalothorax tV; breadth
tV ; breadth of the abdomen ^ ; length of a leg of the second pair \ ;
length of a leg of the fourth pair ^.

104 Mr. Blackwall o?i imdescrihcd Araneidae.

The male is smaller than the female, but the absolute length of its legs
is greiiter, a leg of the second pair measuring ,Vths of an inch; their rela-
tive length, however, is the same. C'ephalothorax dark brown, with a broad
band of a paler hue extending along the middle, and narrow, yellowish
white margins. Mandibles, maxillae, lip, pectus, legs, and palpi, of a deep
brown colour, the fifth joint of the palpi, and the base of the lip being
much the darkest, and the mandibles having a tinge of red. Abdomen of
a very dark l>rown colour, approaching to black on the upper part, freckled
with white, the oblong oval extending along the middle of the anterior part
being imperfectly defined by an obscure border of whitish hairs ; under
part very dark brown, approaching to black, the sides being of a paler
brown. Plates of the spiracles dark brown. The third and fourth joints of
the palpi are short, the latter projecting three apophyses from its anterior
extremity; one, on the under side, is short, strong, and furnished with
two pointed prominences ; the second, which is longer, and acute, is situ-
ated on the outer side ; and the third, which is very small, occurs in front :
the fifth joint is somewhat oval, being prominent on the outer side ; it is
convex and hairy externally, concave within, comprising the palpal organs,
which are highly developed, not very complicated in structure, with a fine
spine on the inner side, curved outwards round their lower extremity ; they
are of a very dark reddish brown colour. The hairs on the cephalothorax
and abdomen of very old males reflect brilliant hues of green and purple
when viewed in a strong light.

I found specimens of this spider, which appears to belong to the section
VigilaricB of M. Walckenaer, on gates and rails, at Oakland, in June 1836;
in which month the female deposits between sixty and seventy spherical
eggs of a pale yellow colour, not agglutinated together, in a cocoon of
white silk of a slight texture, and lenticular form, whose greatest diameter
measures about -f^ths of an inch. The cluster of eggs is subglobose, mea-
suring^ of an inch in diameter.

Tribe, C.t.grad;e, \LatreiIle.
(jrenus, L,ycosa, J

Li/cosa leucophaa.

This fine species has the cephalothorax large, thickly covered with hair,
inversely heart-shaped, depressed on the sides, and in the posterior region ;
its colour is greenish brown, the carina being the darkest, and immediately
below each lateral pair of eyes are two imperfectly defined, yellowish white
spots. Mandibles powerful, conical, vertical, armed with teeth on the
inner surface, clad with grayish hairs in front, and denstly fringed with
pale red ones near the extremity, on the inner side. Maxillae strong,
straight, enlarged and somewhat rounded at the extremity, which Is fringed
with pale red hairs on the inner side. Lip nearly quadrate, being rather
broader at the base than the apex. These paits are of a very dark brown
colour, the maxillae being paler at their extremities. Pectus heart-shaped,
dark brown, covered with hoary hairs. Legs robust, abundantly provided with
hairs and sessile spines ; they are yellowish brown, with spots and bands
of dark brown. The palpi resemble the legs in colour, and are furnished
with a slightly curved claw at the extremity. Each tarsus is terminated
by two curved, pectinated claws. Eyes eight in number, unequal in size ;
four, which are minute, form a row in front, the two exterior ones being
the smallest of the eight ; the other four are placed on the sides of the
anterior part of the cephalothorax, and form nearly a square, the anterior
pair being the largest of all. Abdomen oval, convex above, projecting
over the base of the cephalothorax; it i? rather broader at the posterior

The Rev. R. Murphy on Rectangular Forces 105

than the anterior extremity, and is thickly clail with hair; its colour is
grayish brown, with a faint tinge oi' olive, a broad, obscure, dentated band
of a lighter hue, which terminates in three points, extending from the
anterior part, along the middle, nearly one half its length, and a series
of pale, transverse, curved lines, somewhat enlarged at their extremities,
and diminishing in length as they approach the spinners, occupying the
space between the ternn'nation of the band and the extremity of the abdo-
men : the underside is of a yellow brown colour.

Length, from the anterior part of the cephalothorax to the extremity of
the abdomen, ^ths of an inch ; length of the cephalothorax ^V; breadth
4i^; breadth of the abdomen, -^l; length of a posterior leg 1 inch; length
of a leg of the third pair |ths.

The male resembles the female, but is rather ligliter-coloured, and more
distinctly marked. Though somewhat less, its legs are longer, a posterior
one measuring 1 inch and 1*^. The fourth joint of the palpi is a little
longer than the third ; the fifth is of an oblong oval form, and is thinly
covered with dull brown hair ; underneath, at the upper extremity, is a
sniall aperture containing the palpal organs, which are neither highly de-
veloped, nor complicated in structure, and are of a dark red-brown co-
lour.

I discovered males, females, and young of this species in May, 1836,
among water-worn stones and fragments of rock, on the banks of the river
Llugwy, near Capel Curig, Caernarvonshire.

Crumpsall Hall, Nov. 9, 1836.

XXIII. On the Composition of two Rectangular Forces acting
on a Point, By the Rev. R. Murphy, M.A,*^

T ET two forces, X, Y, act upon a point, which we may sup-
-" pose the origin of coordinates, and let their directions be
those of the axes of x and y respectively.

If the forces X, Y be doubled, trebled, &c., the resultant
would then be the sum of the resultants of two or three, &c.
systems of forces similar to X and Y; that is, it would be ac-
cordingly doubled, trebled, &c., in magnitude, without any
change of direction.

Now as X and Y may be regarded as the multiples of very

Y

small forces, it follows that the ratio -^ remaining constant,

the ratio -^ (R being the resultant) and the inclination of R

to the axis of x will also remain invariable.

The equation to the line in which Uie resultant acts is there-
fore

^=/(x)--^ • • • • ('•)

the form of the function^ being at present unknown.

* Communicated by the Author.
ThirdSeries. Vol. 10. No. 59. Feb. 1837. P

106 The Rev. R. Murphy (5« tJie Composition of

Suppose now two equal arbitrary forces, Z and — Z, to be
applied at the origin in opposite directions, and perpendicular
to the plane of X and Y: it is clear that the resultant will not
be influenced by this couple.

Taking the axis of ;: in the direction of Z, the forces
X, Y, Z, — Z may be compounded, the first and third together,
giving a resultant which acts in the direction expressed by
the equations

% =J^(^j . :r and y = 0 ;
and then the second and fourth, which furnish the equations

"-^=v/ ("y) '^ ^"^^ ^ " ^'

Let the plane of these two right lines be expressed by
% =^ ax •\-b2/, and putting successively 3/ = 0 x = 0, we find

./(4) '-/(I)

The actual resultant must be at once in this plane and in
that of Xi y; its equation is therefore 0 = a x + by or

1/ =z — ~ . X, which, compared with equation (1.), gives

orif ^=-<. Y = # f{a)xf{^)=f{<x§),

whatever may be a and /3 ; and it is exceedingly easy to show
that this equation requiresy (a) to be of the form a*": thus
the equation to the resultant is

y = (x)"- ^ • • • • (2.)

it remains to find n.

Let d be the angle which the resultant of X and Y makes
with the axis of x, and ^ that which the resultant of X — Y
and X + Y makes with the same, the former force X — Y
being in the direction of .r, and X + Y in that of y ; the
equation to this resultant is

y = \x^zy) • ^ • • • (^0

two Rectangular Forces acting on a Point. 1 07

The latter system of forces may be split into two, namely*
first X and Y, which give a resultant R inclined to the axis
of a; at an angle d, and, secondly, — Y and X, the former in
the direction of the negative axis of x, and the latter in the
direction of the positive axis of ^; this system, being perfectly
similar to the first, will give the same resultant in magnitude
inclined to the axis of y at an angle d, and therefore to the

positive axis of x at an angle -^ + 5.

These two equal resultants, therefore, include a right angle,
which their resultant, that is, the resultant of the proposed
system, bisects ; hence

'^ X b 1 . ^ 1 + tan

<^ = -— + fl and tan A = , -4-

4? ^ 1 — tan

and putting for tan 0 tan 5 their values deduced from the
equations (2.), (3.)> we have, whatever may be X or Y,

X + Y\" X" + ¥»

/X+_Yy _ X" + Y"

which evidently requires that n •=. \\ thus the direction of the
resultant is completely known.

With respect to the magnitude, we have seen that -^ re-
mains invariable at the same time with 5, which determines
the direction of the resultant.

Now X may be regarded as the resultant of a force II' in
the tlirection of R, and p iu a direction perpendicular to R.

R' and X have the same inclination as X and R, therefore

R'_ X
X ■" R •

p and X have the same inclination as Y and R, therefore

A- Y
X"" R*

The com]X)nents of X are therefore R' = -rr

X Y

p = -ir-

Similarly Y may be decomposed into R" in the same direction
as R' and R, and p' in a direction perpendicular to R and op-
posite to the direction of p.

P2

108 The Ilev. P. Kcilh on the Classificativn of Vci;ctuhlc$.

ll

llcncc 11"=^.'

,= -X.x

t

Conipouiulin^^ now tlie four Inices f, p\ R', K", llie first two
destroy each other, llie hitler two give a siun ; that is,

11 = R' H- R" = ,; or R« = X^ + Y^

Y

Having proved tliat ^ = tan (3) and IV = X" + Y^ we

easily obtain X = Rcosfl, Y = 11 sin 6, wliich contain the
j)rincipies of the composition and decomposition of any forces
acting on a plane npon one point.
2, Bate;nan's Buililings, Soho, Dec. 23, 1836.

XXIV. On the Classification of Vegetables,
By the Rev. Patrick Kkith, 1\L,S,
[Continued from p. 42, and concluded.]

ZITHERS have innovated upon Jussieu's nomenclature and
^^general plan of arrangement, but it may be doubted whe-
ther they have in this respect improved the system. We will
specify only two examples.

I. M. DeCandolle, Professor of Botany at Geneva, an
acute and skilful systematist, exhibits the first examplt of in-
novation. In his Theorie Elemeutaire and ProdromiiSy he
substitutes the term Exogenas in place of Dicotyledons, and
the term Endogenic in the place of Monocotyledons and Aco-
tyledons; but we can see no advantage that is gained by the
substitution. MM. Desfontainesand Daubenton had already
shown that Dicotyledonous plants are exogenous, and Mono-
cotyledonous plants endogenous, and Jussieu was well enough
aware of the fact. The new terms, we admit, were not yet
imposed ; but if exogenous and endogenous are respectively
identical in their extent, with Dicotyledonous plants on the one
hand and with Monocotyledonous plants on the other, whence
could the advantage of the substitution come? And if you ex-
tend the meaning of endogenous so as to make it include Aco-
tyledonous plants also, we (juestion the legitimacy of the ex-
tension, and contend that their endogeneity is not at all of the
same character with that of the Monocotyledons. Besides,
the change of term.** leaves the affair of method precisely where
it was, while it has the effect of keeping Jussieu and his di-

The Rev. P. Keith on the Cla$sificatio7i of Vegetables, 109

visions too much in the background, as well as of giving room
for the remark that the principles of the system are departed
from. It is enough if the novel terms are introduced to the
aid and illustration of the terms of Jussieu, but not to their
entire exclusion. Neither do the names imposed upon the
minor divisions seem to us to be any improvement. In what
respect is thalamiflora^ better than hypopetalae; or calyciflorae
than peripetalae or epipetalae? If neither one set of terms
nor the other is imposed in strict conformity to the anatomical
structure of flowers, why exclude one term tliat-is faulty
merely to make room for the introduction of another term
that is faulty also? It may be true that the stamens and corolla
have always the same insertion ; it may be true that, in strict-
ness of anatomical speech, their real insertion is always on the
torus^ but as botanical writers seem satisfied to describe them
by their apparent insertion, we are of opinion that, unless some
very obvious atl vantage were to follow from it, the nomencla-
ture and tlivisions of Jussieu ought not to be disturbed. Fi-
nally, the division of Acotyledonous plants into Cryptogamai
and Cellulares does not seem to us to be a sufficiently scien-
tific distribution of the group, because the Cellulares are still,
in fact, Cryptogamous, as well as the Cryptogamai themselves.
But his Dichlamydeae and Monochlamydeae, and Achlamydea^,
we regard as improvements, as affording a convenient ground
of subdivision, and imposing names upon distinctions involved,
though not designated by individual terms in the arrange-
ments of Jussieu.

II. A learned Professor of Botany among ourselves, of high
talent and rej)utation, exhibits the second example of innova-
tion. In his Introduction to the Natural System of Botany he
sets out with'dividing vegetables into two grand groups, which
he calls classes, the Vasculares and the Cellulares, or flower-
ing and flowerless plants. The terms vascular and cellular
stand sufficiently in opposition to one another to form the
ground of a legitimate division; but the feature upon which
they rest is not more important than that of cotyledons, or the
want of them, and gives them, consequently, no apparent claim
to supersede the terms of Jussieu. Besides, the terms era-
ployed by the Professor are, perhaps, not altogether so cor-
rectly descriptive of their respective groups as those employed
by Jussieu. The former are of the same extent with cotyle-
donous plants, and the latter are presumed to be of the same
extent with acotyledonous })lants. But it is very well known that
this is not the fact, as will appear from the following subdivi-
sions into which the Cellulares are distributed by the Pro-
fessor himself. 1st, The Vasculares are subdivided into the

110 The Rev. P. Keith on the Classification of Vegetables.

Exogenseand Endogenaeof M. DeCandoUe, — terms which are
substituted in place of the Dicotjledones and Monocotyle-
dones of Jussieu, though we confess that we cannot see the
utility of the substitution. The Exogenae are next divided into
Angiospermae and Gymnosperniae. The former seems to be
of a dimension too unwieldy, as containing the polypetalous,
apetalous, and diclinous plants of Jussieu, in no less than 165
orders, together with the monopetalae, in 61 orders more;
while the latter seems to be of a dimension too small, as con-
taining only 2 orders, making it nearly the same thing in prac-
tice as if they were all angiospermous still ; so that the pecu-
liarities which the subdivision involves, though important in
themselves, and founded undoubtedly in nature, do not seem
to us to be of any great utility as forming the ground of a
systematic arrangement, — at least, without having the larger
subdivisions subdivided again, into a sufficient number of
groups still smaller. The two main divisions of the Exogenae
are called tribes, and yet the orders belonging to them are
called tribes also. If this is a fault it is one that admits of an
easy remedy, which, we think, the term family would furnish.
The Endogenae are subdivided into petaloideas with minor
groups, and glumaceae, a subdivision which presents to our no-
lice nothing exceptionable. 2nd, The Cellulares are subdi-
vided into Filicoide.T., Muscoideae, and Aphyllae, which might
be a good enough division of the class provided it went by the
name of Acotyledonous. But as the Cellulares are presumed
to have no vascular system, we do not see how they can be
legitimately made to include the Filicoideae, the very diagnosis
of which is that they are ** flowerless plants, with a stem,
having a vascular system and distinct leaves*." The Vasculares
are the flowering plants, the Cellulares are the flowerless
plants. The antithesis is good in flict, but it can scarcely be
said to be good in expression. Flowering and flowerless are
not so happily opposed to one another as powerful and power-
less are, that is, the participle and the adjective, owing to their
grammatical peculiarities, do not form a neat or laudable con-
trast. We admit that this want of systematic symmetry is but
a mere trifle after all, though it ought not to have occurred in
the work in question. To evade the objection arising from the
vascularity of many of the Cellulares, it has been said that
they are furnished merely with ducts, but not with spiral
tubes. This may be all quite true, yet what are ducts but
vessels ?

W« do not pretend to give advice to these able and emi-
nent botanits, knowing that nothing short of the experience
♦ Introduction to Nat, System, p. 310.

The Rev. P. Keith on the Classificatio7i of Vegetables, 1 1 1

of the most profound adept is sufficient to qualify or to entitle
any one to do so; neither do we expect from oiw speculative
demonstrations a result subversive of their practical arrange-
ments. We merely claim the privilege of expressing and re-
cording our sentiments, and of stating what seems to us to be
exceptionable in the above novel method ; or, at the least, not
calculated to facilitate the study of the natural system, or to
improve the method of Jussieu, which stands in need of no
violent innovations to give it in appearance the preeminence
which it possesses in reality. It requires merely a drawing
out of the resources which it has within itself, or the addition
of such supplementary distinctions as the progress of botanical
knowledge may have rendered necessary. In defence of in-
novations, it has been said that the system, though altered, is
still but the system of Jussieu after all. True; for as there is
but one system that is natural, and that sj'stem Jussieu's, bo-
tanists cannot conjure up a new one at their pleasure. "Other
foundation can no man lay than that is laid," — though]he may
disguise the old one, and build upon it a totally different struc-
ture, like Thunberg and Withering in their artificial arrange-
ments. They counted stamens and pistils as did their great
master Linn^us, but they mutilated his system and substituted
one of their own in its room.

But although we do not approve of the change of nomen-
clature, or of the innovations upon system introduced, whether
by M. DeCandolle or by Dr. Lindley, yet we are very far
from wishing to depreciate the merit of their respective works ;
— works exhibiting such abundant proofs of extensive research,
of accurate discrimination, and of just and logical deduction
in the tracing of natural affinities, as will enable their respec-
tive authors to maintain that high station in the scale of bota-
nical eminence which they had previously reached, and will
doubtless secure to them a lasting reputation. If there should
be a difficulty in unlocking Dr. Lindley*s orders, even with
the help of his analytical key, it is to be recollected that Dr.
Lindley has never once attempted to disguise or to palliate
difficulties, but rather to impress upon the mind of his reader
the absolute necessity of unremitted exertion.

Nil sine niagno
Vita labore dedit mortalibus. — Horace y Sat. 9, Lrb, I.

His Introduction may not be adapted to the desultory ap-
plication of the sciolist or trifler, but it will be found to be a
very valuable present to the patient and indefatigable student
who is content to encounter difficulties, and willing to obtain
knowledge at the expense of labour.

If we were called upon to say how it is at all practicable to

, 12 The Rev. P. Keith on the Classification of Vegetables,

adapt the system of Jussieu to the present state of botanical
knowledge without innovating upon its principles, in external
appearance at least, our reply would be, that availing ourselves
of whatever we may find in the works of the above-mentioned
authors, or of others, calculated to illustrate the character of
the groups, or to give perspicuity to the arrangements of
Jussieu, and retaining not merely the foundation but the iden-
tical structure which he reared upon it, we would venture to
add to it a trifle more of extension, or of filling up, in the style
and manner, as much as may be, of the original edifice, that
the masterly traits of the hand of the founder may never be
lost sight of. It will be seen that this adaptation can descend
no lower than to the distribution of classes. The orders and
their arrangement will be continually changing as long as there
shall remain new plants to be collected or new affinities to be
discovered, but we do not see the necessity of any violent al-
teration in the circumscribing of the larger groups. All that
we regard as necessary is comprised in the following tabular
sketch, giving, as we fancy, a neatness of outline to the higher
divisions of the system, by the formal introduction of a very
few distinctions that were either implied in it from the begin-
ning or rendered necessary by the progress of analytical re-
search.

Vegetables,

Giioupl. COTYLEDONOUS PLANTS.— Vascular with
spiral tubes ; — phaenoganious, — bisexual, — angiosper-
mous.
Divis. I. Dicotyledons. — Growth
ferential.

Subd. I. Dichlamijtiece. — Floral envelope double, — a calyx
and corolla.
Sect. I. Polijpctalous,
Class I. Hypopetalae.
II. Peripetalae.
III. Epipetala?.
Sect. II. Monopetalous.
Class IV. Hypocorolla?.
V. Pericorollae.
VI. Epicorolla}.

1. Synanlheras.

2. Corisantherae.

Stibd, 11. MonocJdamydecc. — Floral envelope single,— a
perianth or presumed calyx.
Sect. I. Apetalous.

Class VII. Hypostamineae.

The Rev. P. Keith on the Classification of Vegetables, 113

VIII. Peristamineae.
IX. Epihtamineae.
Sect. 11. Anovialous.
Class X. Diclines.

1. Angiospermae.

2. Gymnosperniae.

Divis. II. Monocotyledons. — Growth endogenous,— cen-
tral. Floral envelope a perianth, often in two rows ;
sepaloid, petaloid, or glumaceous.
Class XI. Monohypogynae.
XII. Monoperigynae.
XIII. Monoepigynae.
Group II. ACOTYLEDONOUS PLANTS. — Cellular,
or, if vascular, without spiral tubes? — Cryptogamous.
Class XIV. Ductulosae. — Cellular, with interspersed
ducts, — seminiferous.
XV. Eductulosse.— Wholly cellular; — gem-
miferous.
Thus the whole of the vegetable kingdom is divided into
two grand groups, without any sacrifice of the technical lan-
guage of Jussieu. For although his system does not actually
exhibit a division into Cotyledonous and Acotyledonous plants,
yet it evidently and essentially involves that distinction.
Hence the introduction of the former term is only the com-
pleting of the contrast which was already implied in the use of
the latter. We have thought it right to put the group de-
signated by the positive term first, because the student cannot
be supposed to know well what is meant by an acotyledonous
plant till he has already found out what is meant by a cotyle-
donous one ; and although the term acotyledonous is negative
in its composition, yet the character which it points out to the
learner is positive, namely, that of the want or absence of co-
tyledons; so that the division is legitimate in whatever aspect
you survey it. But we do not rest content merely with a correct
antithesis. We avail ourselves of all the lights, old and new,
that have been thrown upon either group. In the former we
recognise its vascular, its phaenogamous, its bisexual, and its an-
giospermous characters; and in the latter, its cellular, but par-
tially vascular and cryptogamous characters. We accept them
as auxiliaries illustrative of the respective groups, but we do
not discard the old terms of Jussieu merely that we may use
them as synonyms to new ones of our own.

The first grand group Jussieu distributed into two divi-
sions, dicotyledonous and monocotyledonous — divisions that
are well contrasted and cannot be improved. All that we add
Third Series, Vol. 10. No. 59. Feb. 1837. Q

Hi The Rev. P. Keith on the Classification of Vegetables. .

is merely their exogenous and endogenous characters re-
spectively.

The division of the Dicotyledons we subdivide into Dichla-
mydeae and Monochlamydea^, terms invented by DeCandolle,
but not introducing any new princi[)le that was not already to
be found in the system, and in full and actual operation. For
although the terms were not there, the things signified by them
were there, and were made available to the purposes of ar-
rangement, though not designated by individual names. The
former term is equivalent to the double envelope of calyx and
corolla, and the latter to the single envelope or perianth. They
are all exogenous.

The division of the Monocotyledons J ussieu did not subdi-
vide into any minor groups, and neither do we. We notice
merely the leading peculiarities of the perianth. They are all
endogenous.

In the whole of the above divisions, or subdivisions, the
classes are uniformly founded on the mode of the insertion of
the stamens, as being hypogynous, perigynous, or epigynous.
For although a novice might fancy that the principle of ar-
rangement changes with the change of termination in the
names that have been imposed upon the classes, yet the more
experienced botanist knows that the origin of the stamens and
corolla is uniformly and universally the same, and that what-
ever is predicable of the one in that respect, is predicable also
of the other; and although the introduction of these distinc-
tions, at least in the circumscribing of classes, has been de-
nounced as being wholly and essentially artificial, as well as
utterly and absolutely extravagant, on the score of its exhi-
biting a want of due oeconomy in the husbanding of resources,
and an improvident expenditure of botanical ammunition that
might have been rendered available in the construction of
orders and of genera *, yet this want of due ceconomy is alto-
gether imaginary. There is an abundance of characters re-
maining for the constructing of orders and of genera, as result-
ing from other and important peculiarities discoverable in the
form, structure, or position of the stamens, pistils, ovary and
ovula, fruit, seed, embryo, or from additional and similar pecu-
liarities discoverable in other parts of the flower or plant.
Hence the distinctions founded on the mode of insertion, in-
stead of being an objection to the method of Jussieu, are only
a proof of its excellence, in the facility which they give to in-
vestigation and in their applicability to the whole of the grand
group of cotyledonous plants, whether dicotyledonous or mo-

* Roscoe on Arrangements, Linn.'I'rans., vol. xi. part I. [Or Phil. Mag.
and Annab, N. S., vol. vii.]

The Rev. P, Keith Ofi the Classijication of Vegetables. 115

nocotyledonoiis, dichlamydeoiis or monochlamydeous, polype"
talous, nionopetalous, or apetalous; so that by retaining the
terms and divisions of Jussieu, we are, as it were, always in
company with him, or meeting with him at every turn. Hence
also the plan of procedure and the inquiries to be made by the
student are always the same in all the divisions of the group.
Is the plant cotyledonous or acotyledonous ; is it dicotyledo-
nous or monocotyledonous ; is its floral envelope single or dou-
ble ; is the flower polypetalous, monopetalous, apetalous, or
anomalous; are the stamens hypogynous, perigynous, or epi-
gynous ? This analysis brings him down to the several classes
of the first grand group, which, from their number, are pre-
vented from being surcharged with too many tribes or families.
When botanists are prepared to introduce classes founded
upon the principle suggested by Dr. Brown in his Botany of
Congo and of Terra Australis, that is, the })rinciple of com-
bining into an a^jgregate group, to be called a class, such orders
as are very closely allied, not merely by a single trait, but by
the sum of their affinities, enabling us to dispense with the use
of empirical characters entirely, then it will be time enough
to discard the classes of Jussieu. The objections to which
they are liable apply with equal force to the divisions by which
they have been superseded in the works of the above systema-
tists; all of them being clogged with anomalies that will puz-
zle the learner and impede him in his career, let him embrace
what system he will.

The second grand group Jussieu did not divide into any
minor groups, but introduced merely as a single class. Yet
there is an evident demand for such a division, both from the
number of species which the group contains and from the
peculiarities of structure which several of its tribes display.
We adopt a division founded upon anatomical principles, and
indicated by features sufficiently obvious, as well as designated
by terms which, though novel, are peculiarly appropriate,
namely, the Ductulosa;, or cellular plants with ducts, but with-
out spiral tubes, as it is said ; and the Eductulosce, or plants
wholly cellular; the former propagated, perhaps, by seeds,
the latter by gems or sporules. The above terms appear to
liavebeen originally introduced by Mr. Arnott, of Edinburgh,
and seem to us to be quite unexceptionable *. The groups
which they designate we would erect into classes, the number
being still 15; for though we have thus split one of Jussieu's
classes into two, for reasons that to us seem valid, we have else-
where run two of his classes into one — the Epicorollae synan-
theree, and Epicorollae corisantherae, lor reasons that seem
• Encyc. Brit., art. Botany.
Q2

1 16 Dr, Kane's Contributions to the History

equally valid, by reducing the peculiarities to sections. Be-
yond this our remarks do not extend. It is the part of the
experienced and practical botanist to reduce classes to orders,
or to suborders, it' necessary, and to construct their diagnosis ;
or rather, perhaps, by reversing the process and advancing in
the line of ascent, to reduce orders or suborders to classes;
and to the experienced and practical botanist we are content
to commit the task. P. Keith.

Charing, Kent, Feb. 15, 1835.

XXV. Researches in Organic Chemistrij. — First Series. Con-
tributions to the History of Pyroxytic Spirit and of its derived
Combinatiotis, By Robert J. Kane, M,D,^ M.R.LA.

[Continued from p. 51, and concluded.]

Of the Products of the Oxidation of Pyroxytic Spirit by Sul-
phttric Acid and Black Oxide of Manganese.

"1^7"HEN sulphuric acid, black oxide of manganese, and py-
^^ roxylic spirit are brought into contact, the action which
ensues is very violent, and there is so much effervescence that
unless the retort be taken very large in proportion to the
quantity of materials used there is great danger of its boiling
over. By previously diluting the sulphuric acid with water,
allowing the mixture to cool before adding thereto the black
oxide of manganese and sulphuric acid, this can be to a great
extent avoided, and the quantity of product is also by this
means considerably increased.

The proportions found most advantageous were two ounces
of pyroxylic spirit, three of sulphuric acid and three of water,
and two of black oxide of manfjanese. The mani^anese and
pyroxylic spirit having been first put into the retort and after-
vi^ards the diluted and cold sulphuric acid added, the whole
is to be very gently heated in a water-bath, and as soon as the
mass commences to froth, the fire should be withdrawn, in or-
der to prevent the temperature of the water from rising too
high, in which case the mixture is liable to boil over. Once
commenced, the distillation goes on almost of itself; as the
ebullition moderates the temperature can be again raised, and
the distillation continued as long as any fluid comes over, by
the water-bath. If the water- be then replaced by a sand-bath
and the receiver changed, a liquor can be obtained which is a
dilute formic acid.

The product obtained by distillation in the water-bath is
very heterogeneous; it must be rectified in the water-bath. It
begins to boil under 40° centigrade, and the boiling point gra-

ofPyroxylic Sjnrify and of iU derived Combinations, 117

dually rises to 70° or 80° centigrade. The liquors of different
boiling points must be separated. In the first portions are
found some aldehyd, but principally a new and peculiar fluid,
to w hicli the name formal can be applied, from considerations
which shall hereafter be brought forward. The latter portions,
which boil from 60° to 70°, consist of Dumas's pyroxylic spirit,
together with small quantities of a fluid identical with that py-
roxylic spirit originally analysed by Liebig, and to which I
shall again recur.

The formal, obtained pure by rectification over chloride of
calcium, is colourless, and of a penetrating but aromatic odour ;
it mixes with water in every proportion, from which it is sepa-
rated by the addition of chloride of calcium ; the separation is
however by no means perfect. Pure formal boils at 38° cen-
tigrade. Subjected to analysis,
(No. 1.) 0*502 material gave

Water = 0*428
Carbonic acid = 0*833,
(No. 2.) 0-528 material gave

Water = 0*441
Carbonic acid = 0*875 ;
from whence follows.

No. 1. No. 2.

Carbon = 45*87 45*82

Hydrogen = 9*47 9*28

Oxygen = 44*66 4490

100- 00 100 00

with which agrees the formula

4 atoms carbon = 305*89 45*77

10 hydrogen 62*39 9*34

3 oxygen 300*00 44 89

668*28 100*00

To confirm this analysis by the density of the vapour the
following experiments were made :

(No. 1.) Weight of balloon with air = 37*244 grammes.

vapour = 37*520

Excess = 0*276 grammes.
Volume of balloon = 266*5 cub. cent.

Residual air 2*5 cub. cent.

Temperature of air 16*8 cent.

Temperature of vapour 97*75 cent.
Barometer 0*750 metre.

From whence results,

1 1 8 Dr. Kane's Contributions to the History

Weight of a litre of vapour at zero cen-1 ,, , ^^
.•1 I ^ »,^ . 1 ?"= .^'126 eram.

ti</rade and 0-76 met. bar. press J "

Specific gravity of vapour 4'*4065 —

(No. 2.) Weight'of balloon with air 49-64-5

Weight of balloon with vapour 46*938

Excess =0*293 gram.

Residual air =0

Temperature of air 21^ cent.

vapour 98 cent.

Barometer 0*75 metre.

Result: Weight of a litre 3*1279 gram.

Specific gravity 2*408 —

The theoretical density is

4 volumes gaseous carbon = 3*3712

10 hydrogen 0*6880

3 oxygen 3*3078

3 -f- 7*3670 = 2*4556
It is curious that the variation from theory in these deter-
minations lies in the opposite direction from what is usual,
and the complete coincidence of the two experiments proves
that the deviation results not from manipulation but from the
nature of the fluid itself. The simultaneous though trivial
excess in carbon induces me to attribute botli to the presence
of a trace of aldehyd, from the last portions of which, owing
to the great volatility of the formal, the latter can scarcely be
obtained free.

The empirical formula of this body C4 H^q O3 allows of
many methods of considering its real nature. The first that
naturally occurs is that it was a higher degree of oxidation of
aether, a tritoxide of ethyle A E . O^; but although sensible of
the importance of this view, with respect to the alcohol and
methylene series, and generally to the theory of organic radi-
cals, I am of opinion that the balance of probability inclines in
favour of a different arrangement.

When this fluid is brought into contact with potash or ba-
ryta, Dumas's pyroxylic spirit is formed, and formate of potash;
to illustrate this action we have only to consider that the com-
position of this fluid is C4 H^q O3, or

3 atoms methylene asther = Cg Hjg O3
I atom formic acid = Cg Hg O3

Cg H20 Og

Dumas and Peligot had already proved formic acid to be
the product of the highest degree of oxidation of pyroxylic

of Fyroxylk Spirit^ and of its derived Covibinations, 1 1 9

spirit, bearing the same relation to the methylene that acetic
acid bears to the alcohol series. In fact, the fluid under exa-
mination is the acetai of the methylene series, and is formed
under perfectly similar circumstances; the pyroxylic spirit is
by the sul{)huric acid converted into methylene aether, and
i atoms methylene aether = Cg H24 O4
lose 4 atoms of hydrogen — H^
and gain 2 atoms of oxygen + Oj

Cg H^o Og
an atom of the hence-denominated formal.
As acetai can likewise be considered as being

1 atom aether C4 Hjq ^ \ p u n
1 atom aldehyd C4 H^ O^j ^8 "is ^8»
so Can formal be considered as consisting of

1 atom methylene aether Cg Hg O ^ p tt /-j
I atom methylene aldehyd C^ H4 i\J ^^ "10 '-'a-
To these considerations I shall have occasion to advert here-
after.

Of the Pijroxylic Spiiit analysed by Liebig. — The composi-
tion of formal standing so closely in connexion with the result
obtained by Professor Liebig in his analysis of pyroxylic
spirit, rendered a further examination of this fluid highly in-
teresting, and the more so as Dumas, in the memoir on the
methylene combinations, expresses his inability to account for
the difference between their results, which, as was to be ex-
pected, resulted from the two chemists having examined two
completely distinct bodies.

For the purpose of a new analysis. Professor Liebig was kind
enough to put into my hands a small quantity of his original
pyroxylic spirit which had remained in his cabinet of prepara-
tions. It was purified from some water and a brownish colouring
matter, by rectification over chloride of calcium, and possessed
the boiling point and other properties which that celebrated
chemist had assigned to it. On analysis, 0'470 of material gave
Water = 0-477

Carbonic acid = 0*933,
from whence results the composition
Carbon = 51'-88 ")
Hydrogen = 11-27 > lOO'OO.
Oxygen = 33*85 J
Liebig*s former result was 1 Theory gives

Carbon =54'-75|
Hydrogen =10-75 [lOO
Oxygen sSl-'SoJ

4 atoms Carbon a 53-831
10 — Hydrogen a 10-97 [10000
2 — Oxgen a 35-20 J

120 Dr. Kane on Pyroxylic Spirit and its Combinations,

The result allows no other interpretation, although the sub-
stance was evidently impure, and unfortunately the quantity
remained too small to allow of the necessary operations for ob-
taining it quite pure. Under such circumstances an accurate
determination of the density of the vapour could not be ex-
pected ; nevertheless, the following experiment was made:

Weight of the balloon with air = 46*372 gram.

vapour 46*505 —

Volume of the balloon 285*6 cub. cent.

Residual air vS*0 ■■

Temperature of the air 19*6° c.

. vapour 97*6 c.

Barometer 0*74<8 metre.

Weight of a litre of va}K)ur 2-3674' gram.

Specific gravity ...(air=l) 1'824' —

The theoretical com}iositioii gives

4 volumes of gaseous carbon = 3*3712

10 hydrogen 0*6880

2 oxygen 2*2052

3 -T- 6-2644 = 2*0881.
The difference between the calculated and experimental re-
sult is here considerable, but yet not so considerable as to cast
any doubt on the real composition of the substance.

This fluid presents, in connexion with that previously de-
scribed, some interesting relations. It is evident that both may
be considered as degrees of oxidation of the same radical
ethyle A E = C4 Hjo; but a still moie remarkable connexion
results from considering Liebig's pyroxylic spirit as

3 atoms of methylene aether = Cg HjgO./l p tt ci

1 atom of methylene aldehydene Cc, H^ 6 J^^ "20 ^^'
In this point of view it resembles formal, the formic acid of
the latter being replaced by a lower degree of oxidation of the
same radical, by, in fact, the aldehydene of the methylene se-
ries, formed by the subtraction of four atonjs of oxygen from
methyl ic aether.

I shall return to the liistory of the methylene aldeiiyd in
another paper.

The properties and composition of the bodies just described,
as well as those of the chloral of Liebig, the chloroform and
their congeners, point out the existence of a series which may
now be tabulated, although some of its members are as yet
known only in a state of combination. I shall therefore con-
clude this abstract by a resume of these compounds in the form
they appear naturally to assume.

Hypothetic radical. Formyl C^ H, = Fo.

Formula fo7' the Summation of Infinite Series. 121
Oxide of formyl = Cg H^ O = Fo O

\ C2H4O2 FoO + H,0

Hydrated oxide
Methylene aldehyd

Formic acid Cg Hg O3 Fo O3

Chloroform C^U^C\q Fo Clg

Bromoform Cg Hg Brg Fo Bg

Formal C4H10O3 3 Mtl. O + Fo O3

EL'b5ri;r;;;;7i:"i;} ^^^^-^^ sMti.o+Foo

Chloral and water ... C4 H2 Og CIg + H^ O
giving chloroform ... Cg Hg Clg + formic acid Cg Hg O3.
By the action of water and the chlorine body from pyroxy-
lic spirit, that is, from Cg H4 Og Clg + Hg O, there should re-
sult deutochloride of formyl, C3 H3 Clg, and formous acid,
C3 H3 O3; but I am not yet satisfied of the Composition of the
bodies so formed.

XXVI. Investigation of Formulce for the Summation of certain
- Classes of Infinite Series, By J. R. Young, Esq.^ Professor
of Mathematics in Belfast College,^

T^HE general formulae established in the present paper are,
-■- I believe, new ; and as they are extensively applicable,
and involve but a very moderate amount of numerical labour,
they may, perhaps, be found useful on many occasions. The
investigation, which is very simple, is as follows :
Since any series of fractions of the form

1 .... (A.)

n [ri + p){n + 2p ... {n + mp) ' ' ' ' ^ '^

is equal to — , the difference between a series of the form
^ m p

n(n+p)... [n + {m-- }) p] ^ '^

and another of the form

(n +p) (71 + 2^) ... {n + mp) • • • • V •>'
it follows that a series of the form A^ will be equal to ^ o»

2
the sum of two series of the forms B^ and C^ minus — o — oj a se-

m^ p^

ries of the form B C. Now it is obvious that the two series
whose general terms are B' and C% will, together, be equal

• Communicated by the Author.
27iird Series, Vol. 10. No. 59. Feb, 1837. R

122 Prof. Young*s Investigation of FormulcB for

to twice the series whose general term is B^, minus the leading
term in the other series ; both series being, of course, regarded
as commencing at the same value of n. If this value be unit,
then, calling the series whose general term is B^, S', and that
whose general term is A*, S, we shall evidently have

S --1-/28' ^ \

2
minus — g—j, the series whose general term is

1

(D.)

}

w (w + 'pf (ti + 2pf.,. [w + (w — l)pY(n + mp)
But it is evident, from the original relation

A = — (B - C),
that the fraction D is equal to

_L/ I

mp\n{n-{- pY {n + 2;?)^.. [?i + (m — l);;]^

1

{n + pY {n + 2pf.,» [// + (m — 1) pY (n + mp)

so that the entire series, whose several terms are generally re-
presented by D, will be equal to , the difference between

two series whose corresponding terms are generally expressed
by the two fractions within the brackets. If, however, we re-
gard the latter of these series, that is, the subtractive series, to
originate at the immediately preceding term, instead of at the
term where it actually begins, and then perform the subtrac-
tion, we must add to the result the leading term previously in-
troduced ; that is, supposing the leading term in each series to
have w = 1, we must add the fraction

12 (1 + pY (1 + 2pY ... LI + {m- l)pr

Now the result of the subtraction spoken of is readily seen to
be — (w — l)pS' ; and consequently, by introducing the above
correction, the true difference between the two series will be
expressed by

- \(rn-l)p S- 12(1 +p)m + 2_p)^.. [1 +(m-l)p]}-
It follows, therefore, that the value of the series S must be

the Summation of certain Classes of Infinite Seriei, 1 5^3

2
equal to the expression marked (l.)> together with —3-— 3> the

expression just deduced, that is,

Q — ^ ^ — 2 0/ 3 mp^ 2p + 2

(a.)

12(1 +jt>)*... [1 + (m- 1)^
By this general formula any infinite series qf the form
1

S =

12(1 -^ pf{\ +2pf
1

+ (l +pf{\+2pf{\ +3i;)2... +^^\

(^.1

may be readily summoned, provided only that we previously
know the summation of the series S', whose terms differ
from those of S by the absence of the final factor in the deno-
minator of each. Knowing, therefore, the value of the series

l^"^ (TT7p+(i +2pf "^ (T+T^^"^ ' • ^''^

we may, by successive applications of the formula (at.), pro-
ceed, through all the intermediate summations, up to the sum-
mation of (6.); and in those cases in which the value of (c.) is
unknown, and its approximate summation required,we may ad-
vantageously commence by first summing a few terms of the
more rapid series (^.), and then, by means of the formula (ff.),
gradually descend till we arrive at the proposed form S'= (c).
If in the formula (a.) we assume p = 1, we have

g^j^r2(2^-i)s,_ 3_-i

7»* \ m 1^ . 2*... wi^j V /

and if j> = 2,

When m =zO the sum of the series in each of these cases is
known to be

R2

124 Prof. Miiller ami Dr. Marshall Hall

hence by the first formula we have, when

_ 5^^_197_ 1 1 .

7W - 3, fe - ^^ 216 ~ P.S^S^^'^'^ 2^3^4^5^ "^ '

and so on to any extent.

From the second formula we get, when

m = ] , S = - - ^ = ^-3:3 + 3^^ + &c.

- o Q _ ^ '^^ J- - 1 _L 1 . . ^

7« _ z, » _ — 9 - 12 ^ 32 , 5. + 3^5^72 -^ ^c.

7W - 3, b - ^^^^g 4050" 12.32.52.7' "^ 32.52.72.92 ^ *
and so on as far as we please *.
By means of the general relation

A = — (B - C),

a variety of other series may be summed with great ease, all
those, for instance, investigated by Mr. Phillips, with the aid
of definite integrals, in the Philosophical Magazine for 1832,
vol. xi. A single example of the mode of proceeding will be
sufficient.

[To be continued.]

XXVII. On Professor Muller's Account of the Refex Func-
tion of the Spinal Marrow. Communicated by Marshall
Hall, M.D., RR.S., 8^c,

[Continued from p. 57.]
"T^HE previous considerations however lead us only to the
-■- determination of the fact, that, wherever general twitch-
ings originate from local sensation, this takes place by no other

• A valuable paper upon the summation of this class of infinite series, by
Mr.Woolhouse, may be seen in the Appendix to the Ladies* Diary for 1836,
mid another upon the same subject, by Mr. Rutherford, in the Diary for 1 837.

on the Reflex Fwiction of the Spinal Marrow, 1^5

connexion of sensorial and motor fibres than through the spi-
nal chord. In very many cases, however, after local excita-
tion of the nerves, there ensue not general, but local twitch-
ings, which, however, must also be constantly explained by
the spinal marrow being considered as the connecting link
between the sensorial and motor fibres. The cases which
may be arranged here, are the following :

" 1. The simplest is the case, in which the local sensorial
stimulation, propagated to the spinal marrow or brain, excites
merely local movements, and these in the parts lying in the
neighbourhood, whose motor fibres proceed from the spinal
marrow near the sensorial. To these belong the spasms and
tremblings of the limbs which are severely burnt, &c. Cer-
tain very excitable parts of the organism, as the iris, con-
tract extremely easily, when only slight stimuli excite other
sensorial nerves, and the excitement of the latter is propagated
to the brain, and from it through the oculo-motor nerve to the
short root of the ciliary ganglion, the ciliary nerves, and the
iris. It has long been known that the iris is not excitable by
light, and that light acts on^it only through the medium of the
optic nerve and the brain; this results from the experiments
of Lambert, Fontana, and Caldani. Rays of light passing
through a small cone of paper, or through a small hole in a
piece of paper, and thus transmitted through the pupil, and
falling on the retina, immediately induce motion in the iris,
but have no power when they fall on the iris itself. The iris
of an amaurotic eye moreover is immoveable, as long as the
sound eye is closed, but contracts when the light excites the
optic nerve of the latter. The exceptions in which the optic
nerve of the amaurotic eye still retains mobility*, may easily
depend on an incomplete amaurosis, or if only one eye was
amaurotic, the cause of the motion of the iris in the amaurotic
eye was the open state of the sound eye. The mobility or im-
mobility of the iris of an amaurotic eye can and is only to be
investigated when the healthy one is closed. Every observa-
tion in which this precaution has not been taken is valueless;
Van Deen has therefore deceived himself in his otherwise very
valuable workf, when having in a rabbit cut away one hemi-
sphere of the brain, and the optic nerve of the same side, he
saw the iris contract on the application of alight, and therefore
concluded, that the optic nerve had no influence on the iris.
For as Van Deen brought the light before both eyes {ante
oculos), the same result would follow as when the iris of an
amaurotic eye is moved by the influence of light on the sound

* Sec Tiedemann in his Zeitschrlft, i. p. 252.

t De Differentia et Nexu inter Nervos Vitce animalis et organicie.

126 Prof. Miiller and Dr. Marshall Hall

one. Tiedemanii's interesting discovery that the arteria cen-
tralis retinas is accompanied by a fine twig from the ciliary
ganglion, cannot in this case explain anything. For all vessels
are accompanied by nerves; but this twig is distributed with
the arteria centralis, and is in no proved connexion with the
retina. This reflex action from the brain to the iris takes
place through the oculo-motor nerve, which according to
Mayors experiments at every stimulus excites a contraction of
the iris*. We know from the same author that the cerebral
end of the divided optic nerve, when stimulated, still induces
contraction. Thus, in the contraction of the iris there is pre-
sented a kind of "Statik" of the excitement between centri-
petal-sensorial and centrifugal-motor action through the me-
dium of the brain. Other nerves also may alter this equili-
brium, as the sensorial branches of the trigeminus, for cold
water thrown into the nose produces contraction of the iris.
To these more simple instances of reflected excitement be-
longs also the winking of the eyelids from long impression
of light, or from a loud sound (what has the optic nerve to
do with the auditory?), or from a' threatening impression on
the sight.

" Further, to these belong the contraction of all the muscles
of the perinaeum, the sphincter ani, levator ani, bulbo-caverno-
sus, and ischio-cavernosus in the emission of semen, in conse-
quence of the irritation of the sensitive nerves of the penis ;
in these cases the spinal marrow is the connecting link be-
tween the sensations and motions. Exposed muscles, whose
motor nerves are themselves coincidently stimulated in the
stimulation of the muscles, do not require these centripetal and
centrifugal actions to excite contractions. But the muscles
which are covered by sensitive membranes, and do not them-
selves lie exposed to stimuli, must receive the stimulus to mo-
tion through the sensorial excitement of their sensitive co-
vering, the centripetal action of these sensorial nerves, and the
centrifugal motor excitement from the brain. Thus the con-
tractions of the glottis and air-passages induced by irrespi-
rable acid gases, cannot result immediately from the excite-
ment of these passages, but from the centripetal-sensorial and
centrifugal-motor excitement. Brachet has very fully proved
this. For if the nervus vagus on both sides of an animal be
divided, an exciting chemical substance introduced into the
trachea ceases to act as a stimulus to cough. The cough
from stimulus in the air-passages is induced only by sensorial
centripetal, and centrifugal motor excitement. It is the same
with the contraction of the sphincter ani and sphincter vesicae
* Magendie's Journal de Physiologie, iii. 348.

071 the Beflex Function of the Spinal Marram, 127

urinarise. These muscles cannot themselves be excited to con-
tract by the stimulus of the excrement and urine, but these
substances act on the sensitive nerves of the mucous mem-
brane, and excite the spinal marrow, which, constantly charged
with motor nervous power, acts back on these muscles ; there-
fore after injury of the spinal marrow the contraction of these
muscles ceases.

"2. The second case is, where the sensorial excitement
being quite local, the reflex acting excitement from the brain
is more diffused, as shown already in the phsRUomena which
accompany cough, in which not only the nervi vagi, but the
spinal nerves supplying the thoracic and abdominal muscles,
act in coincidence. It is the same with a number of spasmo-
dic respiratory motions, sneezing, hiccup, vomiting, &c., all of
which are produced by stimuli of the sensitive nerves of the
system of mucous membranes of the respiratory organs and
intestinal canal, which stimuli are reflected to the brain, and
thence put in action the source of the respiratory motions in
the medulla oblongata. I have already in p. 333* mentioned
the remarkable peculiarity, that the system* of respiratory
nerves may be put in action by local stimuli applied to all
mucous membranes. For all the motions, cough, sneezing, vo-
miting, spasmodic involuntary discharge of faeces, involuntary
forcible passage of urine, arise from violent irritation of the
mucous memljranes of the fauces, oesophagus, stomach, in-
testines, and respiratory apparatus. Sneezing has been ex-
plained as a spasmodic affection of the diaphragm; Tiedemannf
and Arnold J still speak thus of it: however, it has probably
nothing to do with the diaphragm, for it is a violent expiration,
and the diaphragm is no expiratory muscle, but the contrary.
Under the incorrect supposition that sneezing resulted from
the diaphragm, the stimulus of the nasal nerves was consi-
dered to be propagated to the spheno-palatine ganglion, the
Vidian nerve, the sympathetic, the cervical nerves, the phre-
nic, the accessorius Willisii, and the facial §. The highly
talented Tiedemann endeavours also to prove that sneezing
does not result from a reflected stimulus from the brain, and
supports himself on the fact, that a man has still sneezed
from snuff, without any sense of smell. Why should he not,
seeing that when the nerves of smell are deficient, the nerves
of common sensation in the nose, the nasal nerves, have still
as in healthy men the perception of tickling? But by minute
anatomy the explanation of a sympathy can still only be

♦ See note p. 53. t Zeitschrifi, i. 278.

J Der Kopftheil det Vegetal, Nervensystem, p. 181,
i Tiedemann, I. c, p. 278.

128 Prof. Miiller and Dr. Marshall Hall

attained through the sympathetic nerve. Yet how can sneez-
ing be explained by a connexion of nerves, by v^^hich every-
thing and yet indeed nothing can be explained ? We may
explain anything by it, because the sympathetic is connected
with almost all nerves; and yet nothing can be explained
by it, because there is not the most remote reason why a
stimulus of this nerve of the nose should produce sneezing
and not many other motions, as, for instance, an increased
motion of the intestinal canal. Nothing can be explained by
it, because in no connexion of the sympathetic with another
nerve is there an actual union of their filaments. In sneezing,
for instance, there is a violent contraction of all the muscles of
respiration ; all the primitive filaments of the intercostal nerves
therefore, which produce contraction of the thoracic and ab-
dominal muscles, must therein be irritated. But how could all
these filaments be irritated from the sympathetic nerve, which
adds to each of these nerves a fasciculus of filaments, that, far
from uniting its primitive filaments with all the primitive fila-
ments of a spinal nerve, only receives them with the latter from
the spinal marrow? Now since primitive filaments cannot im-
part anything to others lying near them, especially in a motor
root without a ganglion, so in this case the sympathetic affec-
tion of all the primitive filaments of an intercostal nerve by the
sympathetic nerve is a perfect impossibility. All these sympa-
thies of sneezing, coughing, vomiting, are done away with, as
soon as we know of the reflex function of the spinal marrow
and brain, which we have before proved ; and no further diffi-
culty lies in the way of the explanation, as soon as one pro-
ceeds from the fact, that all respiratory nerves, the facial, vagus,
accessorius, phrenic, and the other spinal respiratory nerves of
the trunk, by their origin from the medulla oblongata, or their
dependence on it, may be easily excited to convulsive motions
in muscles, by all stimuli, which are conducted from the sen-
sitive nerves of the mucous membranes to the spinal marrow
or the medulla oblongata.

" On every violent stimulus in the intestines, the urinary
bladder, and the uterus, contraction of the diaphragm and the
abdominal muscles easily ensues, lessening the cavity of the
abdomen ; and its contents are forced upwards when con-
tained in the stomach (vomiting), or downwards through the
rectum or urinary apparatus, or through the genitals as in
parturition. The forcible expulsion of faeces is the same
phaenomenon in the lower part of the intestinal canal as vomit-
ing is in the upper. The forcible expulsion of urine presents
the same motions in mental passions; parturition calls into
action the same muscles as produce expulsion upwards in vo-

on the Reflex Fimction of the Sphial Marrow. 129

miting; the parturition too which takes place even after death,
just like the firm apphcation of tlie pharynx round a finger
introduced into it in a beheaded young animal, shows us, of
what important influence, and how intimately connected V^ith
life, this power of the spinal marrow is, of being excited to
motorial discharges by local excitations of its sensitive (or
perceptive) nerves. In many of the stimulations belonging to
this class, in vomiting, &c., the sympathetic nerve may indeed
take some part, but it is nothing more than that of reflecting,
like all other sensitive nerves, the stimulation to the sensorium.
But that it may have this actitm may be shown by an experi-
ment on rabbits; for instance, by tearing the splanchnic nerve
in the abdomen, I have observed frequent twitchings of the
abdominal muscles, and have repeatedly seen the same phaeno-
menon in other rabbits, though the same experiments did not
succeed with me in dogs. *

"3. In the cases mentioned under 2, the reflected motion is-
the motion following on perception, and diffiised through a
large series of nerves, the respiratory nerves, and it arises
most easily from stimulation of the mucous membranes; but
in greater stimulation the difflision of the reflected motions
may be still greater, and affect nearly all the nerves of the
trunk, when the irritable condition of the spinal marrow is
extensive. Among these cases are to be reckoned those of
sporadic cholera, (I do not mention Asiatic cholera because
of the obscurity of that disease,) in which, when severe, spasms
may take place even in the trunk.

" 4. In the reflected motions which arise from violent per-
ceptions of the cutaneous nerves, and not those of the mucous
membranes, the group of respiratory motions is not brought
into associated action, but there more usually occur spasms of
the muscles of all the nerves of the trunk without spasmodic
respiratory motions. The highest degree of this is the epi-
leptic spasm from local nervous affections and the tetanus
traumaticus from injury of a nerve.

"If the first demonstration of the phaenomena of reflection in
the first part of this manual * which appeared in the spring of
1833, and which I have here enlarged with reference to the
observations of Van Deen, be compared with Dr. Marshall
Hall's demonstration, a remarkable correspondence is found
in the ideas and instances.

[To be continued.]

* See note, p. 53.

Third Series, Vol. 10. No. 59. Feb. 1837. S

[ ISO ]

XXVIII. Reply to Dr. Ritchie's Remarks. By the Rev,
J. W. MacGaulev.

To the Editors of the Philosophical Magazitie and Journal.

Gentlemen,

"VT'OU will oblige me by inserting in your next Number the
-^ following reply to Dr. Ritchie's " Remarks" on my paper,
given in your Journal for last month.

I may agree with Dr. Ritchie, that there have been many
writers and few readers on electricity and magnetism ; but
this seems to be a favourite position of his, if we may judge
from the continual effort he makes, as is well known, to prove
that almost every writer on the subject has neglected to read at
least his experiments; I also admit that the person best able to
come forward on the present occasion, has msely left it to
others ; and I am greatly mistaken if maturer reflection shall
not induce him to believe that he also had done msely in
imitating such an example. I did characterize his remarks
at Bristol, on the paper which I then read, as hitter and un-
called for, because they were intended to deprive me of a
claim to originality, and because, like the present, they were
unfounded in fact, and irrelevant to the purpose. Should
any of the expressions I use appear harsh or uncourteous.
Dr. Ritchie will easily pardon me if he recall to his remem-
brance some of those he himself has not hesitated to adopt.
Your readers are told that my first position, — " The spark and
shock obtained from an electro-magnet, on breaking battery
communication, are not the spark and shock of the battery,
nor of the electro-magnet, but most probably the electricity in-
duced on the wire of the helix by the electricity of the bat-
tery, or, if it be true that a current passes along the wire,
the electricity intercepted in its passage from the copper to
the zinc," — is to be found in a paper of his contained in your
Number for last June. Though I presume he has placed
me in his catalogue of those who write, but do not read, I
happen to be very familiar with the few documents he is
able to quote. On looking again to the paper he mentions,
what do I find ? An account of what he deems an improvement
of ^/5 — although many are found who deeni the contrary — on
the magneto-electric machine, and a theory which he builds on
its results ; but not one word as to whether the spark and shock
of an ^Z^c/ro-magnet are derived from the battery or magnet,
or any other given source, which is just the thing, and the
only thing, my first position contemplates. Besides, in his paper

The Rev. J. W. MacGaule/s Reply to Dr. Ritchie. 131

he speaks of a magneto-electric machine^ an apparatus long in
use, and which requires a permanent magnet, but no battery ;
I, in my paper, of an electro-galvanic helix, a species of elec-
trical machine which requires a battery but no permanent
magnet: he, of an arrangement whose expense must be consi-
derable, and whose power can never be great; I, of one easily
obtained, and of almost unlimited energy. If he maintains
that he has anticipated me in his inquiries on the subject, then
they are most unfortunate, since their results are perfectly at
variance with the truth. I shall quote his own words : " It
is a well-known fact, that we receive a more powerful shock
when electricity is being induced on a body, than when the
induced electricity is returning to its natural state." Now it
so happens that in the apparatus I describe in my paper, no
shock is obtained when the electricity is being induced^ a most
powerful one when it is returning to its natural state. So much
for Dr. Ritchie's claim to my first position.

He tella us my second position — " The spark and shock do
not depend, except within certain limits, on the size of the
battery," — is found in Dr. Faraday's papers, " On the length
of the coil influencing the sparks 1 presume he arrives at this
conclusion by the same process of reasoning as that by which
he inferred my first position to be one of his discoveries. But
first, in treating of the spark, Dr. Faraday would not neces-
sarily have included the shock, since they are known to be in-
fluenced by very different laws; and secondly, in these cele-
brated papers the inquiry is about the spark from the se-
condar^ current, obtained not from an electro- but a permanent
magnet, and without the agency of a galvanic battery, which
my second position supposes.

He says that in my third position I assert, that " mag-
netism within a helix proportionably injures its effect." He
quotes, indeed, words which I have used, but he gives an}'-
thing rather than the principle I aftirm, simply because the
context is suppressed. Why, if 1 take an isolated expression
of his, I can make his talk very egregious nonsense. The
assertion I do make is this, and I repeat it, — that if the iron
of an electro-magnet retain, from the nature of its material,
the presence of a keeper, or any other cause, the magnetism
induced upon it, the shock and spark will be proportionably
diminished, because the magnetism of the bar, by its induc-
tive action on the helix, would prevent the perfect restoration
to equilibrium of the electricity disturbed in the helix, by
giving to the bar in a greater or less degree the nature of a
permanent magnet, from which, by means of a helix coiled

S2

132 The Rev. J. W. MacGaule^^'s Reply to Dr. Ritchie.

around it, neither shock nor spark can be obtained, — will any
one deny this except Dr. Ritchie? I believe not.

He tells us my fourth position — "The real power of the bat-
tery is not increased, but diminished by the electro-magnetic,
or rather electro-galvanic helix," — was known long since,
and that Sir Humphry Davy was well acquainted with it. Sir
Humphry Davy knew that the shorter the wire connecting the
poles of an ordinary galvanic battery the better the effect, but
that the great power we may obtain by means of the long "doire
of the helix and a battery is not the increased poxver of the
battery, as others of high celebrity long after his time have
supposed, is what he neither contemplated nor examined. My
paper does not consider the simple wire connecting the poles,
or an ordinary battery, but the peculiar and seemingly ano-
malous action of a peculiar arrangement of wire in great
length, and possessing very peculiar properties.

Dr. Ritchie concludes by saying, " that the only thing nexxi
in my paper is 2ifact which is not correct, of which any one
who possesses a magneto-electric machine may easily satisfy
himself." In the name of common sense, what induces Dr.
Ritchie to talk of a magneto- electric machine on this occa-
sion ! This mistake seems to have run through his mind
the whole time he was criticizing and so severely condemning
me, and what is worse, to have been uncorrected for many
months: not a word about such a machine, nor a single ex-
periment made with it, is found in my entire papers. I make
experiments with one apparatus, he tries the same experiments
with a very different and inappropriate apparatus ; and then,
forsooth, because his results are different from mine, he most
kindly remarks that my only new fact is a false one. Is not
this hitter'^. — is it not uncalled for'^. The circumstance he
denies was noticed by several when I experimented in the
Theatre of the Royal Dublin Society, and from whatever
cause it may have arisen, was undoubtedly worthy of attention.
I trust that when Dr. Ritchie next honours me with " re-
marks," if they are not ushered in by a more kindly prelude,
they will at least be substantiated by facts, and sustained by
more conclusive reasoning.

Your obedient Servant,
79, Marlbro'. street, Dublin, JaMES WiLLlAM MacGaulEY.

January 9, 1837.

[ 133 ]

XXIX. FiiriJier Experiments on wpeculiar Voltaic Condition
of Iron, Bj/ Professor SciiOY.iiBFAN of Bale; in a Letter to
Mr. Faraday.

Dear Sir,

SOME weeks ago I had an opportunity to send you a paper
" On a peculiar action of Iron upon some Salts," which
I hope will by this time have reached you. Having since
observed some new facts regarding the transference of the
active and inactive state of iron from wire to wire, facts which
I think to be of some importance to electro-chemical science,
I take the liberty to communicate them to you by writing.

First Fact, — A and B p

represent vessels contain-
ing nitric acid, sp. gr. 1*35,
and C P D a platina wire
connecting them. If the
oxidized end E, of an
iron wire E F, be put into A, and F afterwards into B, F be-
comes active, though a current passes from F through the acid
into D (the usual condition for calling forth the peculiar state).
Second Fact, — If C P D be a wire of a metal, which is acted
upon by the acid in A and B, — for instance, silver, copper,
iron, brass, &c., — the end F of the iron wire will turn inactive
on its being plunged into B, after the immersion of the ox-
idized end E in A. The same effect takes place if the middle
part of the connecting wire P consists of platina, and the
ends C and D of silver, copper, &c.

Third Fact. — If C P D be an iron wire, its end D inactive,
C active, and the end E (not oxidized) first plunged into A,
and F afterwards into B, F becomes inactive, that is to say, as-
sumes the state of D. The inactive iron end D may be re-
placed by platina, and the active one C by any metal, which
is acted upon by the acid in A, without causing a change
of result by so doing.

Fourth Fact, — If everything be precisely as in the forego-
ing case, but E oxidized and first put into A, F becomes like-
wise inactive on its being afterwards immersed in B.

Fifth Fact. — If C P D be an iron wire, the end D inactive,
(made so not by heating, but by immersing it in strong
nitric acid,) and the end F put into B, and E afterwards into
A, not only E, but also D turns active. Whatever may be
the number of wires similar to C P D, all their inactive ends
in B turn active under the circumstances mentioned, though
these wires do not touch each other at any point.

13'Jf Professor Schoeuhe'm^s/uriher Experiments

Sixth Fact, — If the four electrodes of two piles (each con-
sisting of about half a dozen of pairs of zinc and copper) be
introduced into two vessels containing common nitric acid, in
such a manner that the positive electrode of one pile and the
negative one of the other dip into the same vessel, and the
oxidized end of an iron wire be plunged into any of the ves-
sels, and its ordinary end afterwards into the other one, the
latter becomes inactive, just in the same way as if the two vessels
were connected by a copper wire. But to obtain this result
it is requisite to bend up the second, that is to say, the or-
dinary end, thus ~Xy previously to immersion.

Now, why does F in the first case not become inactive by the
current produced by its being plunged into B? It seems to
be an indispensable condition for calHng forth the inactive state
in iron, that at the moment of its being immersed into the acid,
a current of a certain energy should be passing through it. The
current produced by the part of the metal immersed, is of
sufficient strength w^hen both ends of the iron wire plunge
into the acid contained in only one (small) vessel ; but when
this same current has to pass through the acid of two vessels,
and besides to enter and issue into and from the connecting
platina wire, its strength is diminished below the degree ne-
cessary for producing the effect in question. But if this way
of accounting for the fact be correct, it may be asked, how it
comes, that with a connecting wire whose ends are attacked
by the acid of the vessels, different results are obtained? It
is obvious, that in the second case, two currents moving in
opposite directions and originating in C and D are established,
as soon as the iron wire E F has connected the vessels A and
B. Besides these currents, a third one is produced by the
immersion of F in B. But this current having to move the
same way which the current in the first case must pass, why
is its effect different from what that of the latter is ? Now
it seems to me, that if two currents of opposite directions cir-
culate through our circuit of the second case, they remove in
some way or other the obstacles which the third current
(in itself of weak power) would have to overcome, if it were
moving alone through the circuit; or in other words, if two
opposite currents cross the nitric acid, its conducting power
for a third current is increased. In the third case, there are
likewise two opposite currents established, as soon as F dips
into B; one produced by C, the other by E ; and there is again
a current excited by F, which must be considered as the cause
of the peculiar state of this end. It is only to be wondered at
why D, when having been made inactive by immersion in
strong nitric acid, or by the help of platina, is not rendered

on a peculiar Voltaic Condition of Iron, 135

active by the current produced by F; for, the same rea-
sons why F turns inactive, should throw D into action. But
from many facts it appears, that a much stronger current is
required to change the inactive state into the active one,
than that required to render an ordinary wire inactive. The
fourtli fact will be accounted for, if we consider that in this
case a current passes from C to F, which added to that pro-
duced by F itself, becomes strong enough to call forth the
inactive state in F, though it is still too weak to render D
active; and probably only so on account of the absence of
two other opposite currents. As to the fifth case, E becomes
active, because in the moment of its immersion there are no
two opposite currents put into circulation ; the current pro-
duced by E is therefore too weak to excite in E the peculiar
state; and there are besides the two currents of C and F,
which would more than neutralize the current of E. Now the
current originated by F being continuous, and besides power-
ful, compared to that excited by an iron wire becoming in-
active, would of itself throw D into action, but its energy is
still increased by the two opposite currents produced at C
and E. About the sixth fact I say nothing, as its connexion
with the foregoing ones is sufficiently clear.

I allow that the inference I have drawn from the facts stated
is rather hazardous, and in apparent contradiction to the gene-
rally established principle, that two equal but opposite cur-
rents annihilate each other, and that the circuit through
which such currents move, is exactly in the same state as if
no currents were passing through it. But 1 think that with-
out adopting my view of the subject, the facts spoken of re-
main quite unaccountable. Whatever cause, however, they
depend upon, in my opinion they deserve to be closely searched
into, as their minute investigation will, no doubt, lead to inter-
esting results.

The last Number of the Bibliotheque Universelle contained
a paper of mine on the relation of iron to oxygen, which
happens to be full of most unhappy misprints. They will, no
doubt, be corrected in the forthcoming Number. I am very
anxious to know your opinion about the contents of the said
paper.

Begging your pardon for having repeatedly intruded upon
you a badly written letter, I take the liberty of calling myself,

Yours very truly.

Bale, Dec. 26, 1836. ScHOENBElN.

[ 136 ]
XXX. Proceedings of Learned Societies,

GEOLOGICAL SOCIETY.

Nov. 16, A Paper was first read " On indications of changes in

1836. -^ the relative level of Sea and Land in the West of
Scotland," by James Smith, Esq., of Jordan Hill, F.G.S.

In the West of Scotland are two superficial deposits. The lowest,
in some districts called " Till," consists of stifFunstratified clay, con-
fusedly mixed with boulders. It rarely contains organic remains, but
stags' horns, tusks, and bones of the elephant have been found in it
in the bed of the Union Canal at Kilmarnock, and remains of the
elephant associated with marine shells at Kilmaurs in Ayrshire.

The upper deposit is composed of finely laminated clay, overlaid
by sand and gravel; and marine remains of existing species occur
in every part of it, but most abundantly in the clay. It has been
traced by Mr. Smith, on both sides of the Clyde from Glasgow to
Roseneath and Greenock, at points varying from 30 to 40 feet above
the level of the sea. He has also observed sea- worn terraces on each
side of the Clyde below Dumbarton and between Cloch Light-house
and Largs.

The following are the principal localities, mentioned in the paper,
at which the clay bed has been examined.

A brickyard atGlasgow, 30 feet above high-water mark, where the
author found the remains of six species of recent marine shells of
common occurrence on the adjacent coasts of Scotland ; also a branch
of an elm and an oak-tree with its roots. The canal from Glasgow
to Paisley and Johnstown was excavated in the clay at the height of
40 feet above the sea, and numerous remains of 26 species of existing
marine testacea were found in it. In a pond lately dug at Paisley,
a bed of clay was exposed, to which a violet colour had been given
by decomposed muscles, in a manner similar to that described by
Mr. Lyell in his memoir on change of level on the coast of Sweden*.
In the brick and tile works around Paisley, and in the adjoining
parishes, recent shells are abundant. Near Renfrew, cockles are so
numerous, that a farm and hill, are called Cockle Farm and Cockle
Hill. At Johnstown, which is about 8 miles from the sea and at a
point about 40 feet above its level, in making a well, there were
found bones of fishes and sea-fowls, fragments of sea-weeds, crabs'
claws, and numerous layers of shells imbedded in sand and clay,
which rested on a deposit of'' till " more than 70 feet thick. Besides
these localities, recent shells have been noticed at Helensburgh, also
near Loch Lomond, at Dalmuir, and the shores of the Firth of Forth.

Withrespectto the origin of these deposits, Mr. Smith isof opinion,
that the lower or *' till " resulted from the violent though transitory
action of a body of water; but that the upper was gradually deposited
at the bottom of a sea of sufficient depth to protect it from the agita-
tion of waves, and that it was raised to its present level by a process

♦ Phil. Trans., 1835, pp. 5, 7. [An abstract of Mr. Lyell's memoir ap-
peared in Lond. and Edinb. Phil. Mag., vol. vi. p. 297.]

Geological Societi). \ 37

analogous to that described by Mr. Lyell as now taking place on the
shores of tlie Baltic*.

Of the period when the change was effected, Mr. Smith offers no
conjecture ; but he states that it must have been anterior to the oc-
cupation of Britain by the Romans, because the terminations of their
wail on the shores of the Forth and the Clyde were constructed with
reference to the present level of the sea. He also adds, that on the
banks of the Firth of Clyde there are vitrified forts andtumuli to which
the same observation applies; and that no human remains or works
of art have been found in the clay.

At his first examination, the author concluded, judging from the
sea-worn terraces which skirt the coasts, that the change of level
could not exceed 40 feet, but he has since observed the clay at the
height of 50 feet J and Mr. Buchanan of Arden has found oyster-
shells near Loch Lomond 70 feet above the sea. Mr. Smith, how-
ever, believes that at the period when the clay was accumulated and
the terraces formed, the relative level of sea and land was stationary,
and that, if we may judge from the comparative dimensions of the
ancient terraces with those now forming, the period during which the
level was thus stationary must have greatly exceeded 2000 years.

The important question, if the Fauna and Flora of the period when
this deposit was accumulated were identical with those of the present
epoch, Mr. Smith says it would be premature now to determine. A
very great proportion of the species of shells, amounting in all to about
70, abound in the present seas; and it is worthy of remark that Astarie
Ga;e«5w, which is common in the clay at Helensburgh, is found in
great numbers in the Gare Loch ; on the other hand, some of the
species have become very rare, if not extinct with reference to the
coast of Scotland.

In alluding to the geological position of the upper deposit, the
author says, that it must be placed among the newer pliocene 3 and
as it belongs to one of the first steps in the descending series, every
circumstance connected with it should be carefully observed and re-
corded, that researches into the more ancient formations may be con-
ducted with greater success.

A paper was afterwards read ** On the distribution of Organic
Remains in the Oolitic formations on the coast of Yorkshire," by
W. C. Williamson, Esq., Curator of the Natural History Society of
Manchester, and communicated by the President.

In a former paperf Mr. Williamson gave detailed sections of the
lias in the Yorkshire coast, with a view to determine how far its fossils
might be useful in recognising the different beds of the formation at
other localities. The paper read at this meeting was prepared with
the same intent, and gave detailed accounts of the fossils of the (1)
inferior oolite, (2) the lower shale and sandstone, and the (3) Great
or Bath oolite.

1 . The point selected by Mr. Williamson as affording the best section

* Phil. Trans., 1835, p. I.
t Lend, and Edinb. Phil. Mag., vol. v. p. 222.
Third Series. Vol. 10. No. 59. Feb, 1837. T

If? 8 Geological Society.

of the inferior oolite on the Yorkshire coast is Blue Wick ; and the
following is the succession of the strata which it presents in ascend-
ing order :

Feet.

1 . Thick beds of dark grey finely grained sandstone . . 20

2. Irregular beds of yellow sandstone '20

3. Hard ironshot sandstone containing small pebbles. . I J

4. Irregular beds of yellow sandstone, in some parts

ironshot, and inclosing layers of pebbles 30

5. Hard ironstone, many fossils 4

6. Hard ironstone, no fossils 8

The beds No. 1. contain, in their lower part, argillaceous nodules
resembling those of the Alum shale, and inclose great numbers of
Ammonites striatuluSj Lingula Beanii, Orbicula reflexa, and, in less
abundance, an Avicula, resembling^. ccAiwo^a, and Terebratula bidens^
Above this nodular bed no fossils have been noticed till within 1 0 feet
of the top of No. 1, where anotlier layer of similar concretions occurs,
inclosing portions of an Astacus resembling in some respects Astacus
rosiratus, and a species agreeing with one found in the Cornbrash.
A little nearer the top of No. 1. is a thin seam containing great
numbers of Vermetus compressus, which is found also in the coralline
oolite of Yorkshire.

The division No. 2. presents throughout its whole thickness small
fragments of dicotyledonous wood with an undescribed Belemnite j
and towards the top are found, though rarely, Mya litterula, and still
higher two species of Ammonites apparently new.

The bed No. 3. contains the same Belemnite as No. 2, but is
characterized by great abundance of Terebratula iriUneata,

No. 4. is destitute of fossils, except near its junction with the over-
lying bed, where it contains the Belemnite and Avicula of Nos. 1.
and 2.

The bed No. 5, though not more than 2 feet thick, incloses the
greater part of the fossils of the inferior oolite of the Yorkshire coast,
and the following is a list of the species given by Mr. Williamson, as
occurring chiefly in the middle and lower portions of the bed :

Trochus graniclatus, T, bisertus, T. pyramidalis. Solarium calix, Nerita
costata. Turbo Icsvigatus, T. funiciilatus, Rostellaria compositUy Natica ad-
ductay N. tumiduluy Terebi^a vetusta, Acteon humeralis, Auricula Sedgviciy
Ostrea Marshiiy O. solitaria, Pecten virguliferus, P. abjectus, Trigonia angu-
latOy T. costata, T. striata, T. gibbosa, Avicula Braambui-iensis, Astarti' ete-
gans, A. minima^ Modiola pulchra, M. cuneatay Mytilus sublcevisy Cardifa
similis, Nucula axiniformisy Isocardia concentricay Cardium incertum, Phola-
domya ovalis, Unio abductuSy Gastrochcsna tortuosa.

The upper part of the stratum is characterized by Turrilella muri-
cata, T. quadrivittata, T. humifusa, T. cingenda (Phillips) in great
abundance, Melania HeddingtonensiSy Terebratula obsoleta, and Ca-
ryophyllia convexa.

In No. 6, the highest stratum of the inferior oolite^ no fossils have
been noticed by Mr. Williamson.

2. Immediately above the inferior oolite lies the lower sandstoneand

Geological Society, 13$

shale, an important formation on account of the absence of marine
remains and the presence of terrestrial plants. With the exception
of a similar series of beds above the great oolite/this formation is the
most irregular in its subdivisions of any on the Yorkshire coast. The
only point at which the upper and middledivisions of theseriesare fully
developed are the cliffs between Cloughton Wyke and Blue Wick ;
the remainder of the coast exhibiting only the lower divisions. The
following is the succession of the beds in ascending : p^^^

1. Black carbonaceous shale, no vegetable remains . . 10

2. Hard, pale, gritty sandstone, containing at its junc-

tion with No. 1. great abundance of a new species
of Calamites, also fronds of Zamia gigas, and a
remarkable fossil apparently connected with the
fructification of aCycas 20

3. Shale 10

4. Gritty sandstone 20

5. Softish sandstone containing fine specimens of Equi-

seium columnare^ all in a vertical position with their
roots downwards 8

6. Soft black shale 3

7. Sandstones and shales 1 70

8. Dark shaly sandstone 8

9. Hard grey sandstone 6

1 0. Black shale 2

1 1 . Laminated sandstone containing great abundance of

various species of beautiful ferns, Cycadean plants,
and Equiseii, also towards the lower part three
seams of soft jet 6

The following are the species enumerated by Mr. Williamson : — Equisc-
turn later ale y Liijco'podiles Williaynsonis, L.falcatus, Thuites expa7i.stiSy Sphe-
nopteris longifoliay S. hymenophylloideSy Pecopteris ligafa, P. curtata, P. Whit-
biensis, P. Williamsonis, Ptcrophyllum pectinoides, P. minus, O topic ris acu-
minata, Ci/clopteris digitatUy TcBniopteris vittata, Solenites Murrayana.

Feet.
12. Sandstones and shales containing no well-preserved
plants, but about 90 feet from the top a bed of coal

1 foot thick 170

The plants of this system differ from those of the upper sandstone
and shale by the abundance of Pterophyllum minus, Otopteris acumi-
nata, Sphenopteris hymenophylloides, and the deeply lobed CycLopteris
digilata, and is characterized by Pterophyllum pectinoides, Equisetum
laterale, Lycopodytes falcatus, and by a singular frond supposed to
belong to a Cycadean plant. With respect to the vertical Equiseti in
bed 5, Mr. Williamson is of opinion that they did not grow where
they are found, but were transported, not, perhaps, from a great
distance j and that their perpendicular position is owing to the roots
of this description of plants being specifically iieavierthan the stem.
3. The Great or Bath oolite varies very little in its characters or fos-
sils, except for 8 or 9 feet from the top, where, according io Mr.

T2

140 Geological Socielj/.

Williamson's observations, it presents two forms very different both
in structure and organic remains. The localities referred to in the
memoir for the general structure of the formation are Cloughton and
White Nab, and for the u}3per beds Cay ton and Gristhorpe Bays.

Section of the general structure of the Great Oolite.

Feet.

1. T\\e lowest beds consist of a very hard blue lime-

stone, sometimes oolitic and destitute of fossils,
except in the upper part, where the stone is softer,
and where the author has found Osirea edulina,
Amphidesma decurtatumy Mya calceiformis, a large
undescribed Ammonites, and at the junction with
the next bed Belcmnites compressus, B. Aalensis,
Melania Heddingtonensis, Amphidesma decurtatumy
Serpulae, and long tuberculated spines of a Ci-
daris, but no portion of the Cidaris itself. ... 14 to 20

2. Hard blue fine-grained oolite, sometimes ironshot,

and apparently devoid of organic remains 6

3. Soft or hard bluish clay, tinged, at some localities,

with iron. It contains at least 1 1 species of fossil
shells,which are most abundant at Cloughton Wyke,
and some species which occur there have not been
noticed at any other point. This bed also contains
the remains of a Saurian, which the author is in-
duced to consider a new species of Plesiosaurus. . 2
The shells given by Mr. Williamson are, Rostellaria co7nposita, Acteon
glaher, Terehra vetusia, Phasianella cincta, Trochus, Avicula Braamhurien-
sis, Gervillia acuta, Cucidlea cancellata, Astarte Jiiinima, Cardila similis,
Pholadomya acuticostata.

4. Nodular ironstone, sometimes inclosing fragments of

Ammonites Blagdeni 6 to 12 in.

5. Clay containing Avicula Braamhuriensis, Amphidesma

decurtatum, and a Gervilia 1ft.

6. The top strata consisting of layers of nodular iron-

stone and argillaceous oolite 3

The lower part of this bed is characterized by the presence of Perna
quadrata, and the upper by numerous remains of the following shells:
Melania Heddingtonensis, Ammonites Blagdeni, Terehratula spinosa, Gjy-
phcBa nana, Ostrea Marshii, Pecten lens, Plaaiostoma interstinctum (c)*, Avi-
cula Braamburiensis (c), A. echinata{c) ? Gervilia acuta (c), Trigonia cos-
tata, T. clavellala, Astarte minima (c), Corbula deprcssa, Pinna cuneata,
Pentacrinites vulgaris, Cidaris vagans.

The author then describes the upper beds of the Great Oolite at
the two extremities of Cayton Bay, and at low water at the south
side of Carnelian Bay.

Top. Irony nodules, without organic remains 1 ft.

Extremely hard ironshot rock, composed almost wholly
of fragments of fossils, viz. Millepora straminea, pa-
pillae of a Cidaris, innumerable small spines, probably

• (c) The species thus distinguished are found in the greatest abundance.

Hoj/al Socictij, 141

of Cidaris vagans, murlcated spines, and joints of a
Penlacrinites 8 ft.

This bed Mr. Williamson appears to consider peculiar to the lo-
calities mentioned, not having observed it elsewhere.

He afterwards describes the upper beds of the Great Oolite at the
south point of Cay ton Bay. Immediately above the nodular iron-
stone bed is a very thick series of sandstones and shales surmounted
by a seam of argillaceous oolite, containing Av'icula Braamburiensist
and similar to that which forms the top of the Great oolite at White
Nab (No. 6. of the section), with the exception that the nodular iron-
stone is wanting. This system of sandstone and shale, considered
by Mr. Phillips to belong to the upper marl and sandstone, is, in Mr.
Williamson's opinion, a distinct and merely local deposit included
in the superior division of the Great oolite. It contains most of the
fossil plants assigned by Mr. Piiillips to the upper marl and sandstone,
and several which are new and peculiar to it. Aii ascending sectional
list is given of this deposit, commencing with the 1 foot bed of irony
nodules, and passing through 35 feet of alternations of shale, with
ferruginous and other sandstones, ends in the seam of argillaceous
oolite, which is said to be overlaid by the upper sandstones and shales.
One of the beds of shale contains a vast number of plants, amounting
to above 40 species. The following list is given by Mr. Williamson :

Pecopteris lobifolia, P. insignis, P. nnJans, P. polypodioides, P.projnnqua,
P. Williamsonis, P. acuti folia, P. obtusifolia, P. denfata, P. exilisy P. cce-
spiiosa, Neuropteris recentior, N. Hgata, N. arguta, Sphenopteris stipata,
S. Williamsonis, Cyclopteris digitata, Glossopieris Phillipsii, Tcsniopieris
vittatu, T. major, Solenites Murrayana, Lycopodites Williamsonis, Sphtsridia
paradoxa, Pterophyllum comptum, P. Pecten, P. minus, Otojiteris cuneata,
0. Beanii, Ctenis falcata, JDictyophyllum rugosum, Cycadites tenuicaulis.

Two shells are occasionally found in these beds, and are considered
by the author to be allied to the genus Anodon.

In conclusion, Mr. Williamson says, that the characteristic shells
of the Great oolite are few, as they bear a general resemblance to
those of the cornbrash and inferior oolite.

ROYAL SOCIETY.

Address of His Royal Highness the President^ delivered at the
Anniversarif Meeting, Nov, 30, 1836.
Gentlemen,
I APPEAR before you, after an absence of two years from this
chair, under circumstances which deeply affect my feelings. I have
been secluded, during nearly the whole of that period, from the
active business of life and of society, by the slow but sure ap-
proaches of almost total blindness ; by preparations for a most de-
licate and, to me, most important operation, and by the precautions
which were necessary to accomplish my recovery, after it had been
most skilfully and successfully performed. In resuming now, there-
fore, my public duties in this place, I feel sensibly the novelty of
my situation, as if I were entering, by the blessing of God, upon a
new tenure of existence, which, whilst it offers to my view many

142 Ttoyal Society,

prospects of happiness, imposes upon me likewise heavy responsi-
bilities ; and I can only express my fervent hope and prayer, that
the same merciful Providence which has vouchsafed, through his
api^ointed means, to restore me to sight, may enable me, like a
willing and humble-minded scholar, to apply the lessons taught me
by the experience of my past life, to the just and useful regulation
of that portion of my course which I may be still permitted to run.

It is my first and most pleasing duty, Gentlemen, to thank you
for your congratulations upon my recovery, which have been con-
veyed to me in terms most grateful to my feelings. I have on many
occasions experienced both your kindness and forbearance, and I
deeply regret that circumstances should so frequently have com-
pelled me to appeal to them: but at no moment could the expression
of your good-will be more welcome to me than at the present, when I
am enabled to reappear amongst you, upon being again entrusted
with the possession of that blessing, the value of which I have learnt
to appreciate more fully by my experience of its privation.

Could 1 have foreseen, when the progress of my malady first
removed me from public life, the length of time which was to
elapse before its termination, even in case 1 could have felt assured
that it would end as fortunately as it has for me, I would not
have ventured to trespass, so long as I have done, upon your in-
dulgence, but would at once have retired from the proud situa-
tion of your President ; for though I could rely with perfect confi-
dence upon the cordial cooperation of the members of the Council,
and should have felt satisfied that they would not allow the real in-
terests of the Society to suffer from my absence, yet I could not
have continued altogether free from alarm, lest its dignity should
be lowered in public estimation, were its affairs long allowed to be
conducted with an incomplete establishment ; or the becoming au-
thority of this Chair should be lessened by frequent changes in its
occupation, particularly on great and public occasions. I was always
led to believe that the disease under which I laboured would have
been sufficiently advanced to justify an operation much sooner than
eventually proved to be the case, and I was therefore induced to
hope that my absence from the Society would not have been pro-
longed for such a period as to be productive either of reasonable
complamt, or of serious inconvenience. When, however, the day of
your last Anniversary approached, and that hope had proved
delusive, I felt it my duty to resign my trust, however reluctant
to sever myself from a body with which I am so honourably
connected ; and I only consented to continue in its occupation,
when kindly pressed to do so by the members of the Council,
under the conviction that the time for performing the operation
w as so near at hand, that its success or failure would speedily decide
whether I should be capable of again taking an active part in
our concerns, or be compelled to terminate my official connexion
with you for ever. I thank God that I am now enabled, in person
to express my heartfelt gratitude for your kindness to me on all occa-
sions, and especially on the present ; and I beg you to feel assured

Anniversary Address of the President. 14S

that the remembrance of your sympathy with my affliction whilst it
continued, and of your warm congratulations upon my ha])py re-
covery, will ever tend to cement more closely the ties of affection
and friendship which subsist between me and the Fellows of the
Royal Society.

My necessary absence from my duties amongst you will prevent
my entering in much detail upon the ordinary transactions of the
Council, and of our weekly meetings durinq- the last year ; for a parti-
cular statement of which i must refer to the Report of the Council,
which will be read to you by one of your Secretaries, Dr. Roget.
There are only two topics connected with them to which I feel my-
self particularly called upon to allude.

The fii*st is the publication of the classed catalogue of our library ;
the second relates to the discussions which have been attempted to
be raised upon the Minutes of your proceedings on the ordinary
days of your assembling during the last year.

It is well known to you, Gentlemen, that, after the transfer
of the Arundelian MSS. to the British Museum, and the great
additions which your library received from purchases and ex-
changes of books, necessarily consequent upon that transaction, Mr.
Panizzi was employed by the Council to draw up a classed cata-
logue of its contents. Such a compilation it was considered would
be of great value, not merely to the Fellows of the Society but to
men of science generally, by making known to them the treasures
of a library singularly rich and complete in journals, and works on
mathematical, physical, astronomical, and anatomical science, and
by presenting them in such a form that persons engaged in works
of research, or in any specific subject of scientific inquirj'^, might be
made at once acquainted with nearly all the sources from whence
they could derive information. This catalogue is now printed, or
more correctly speaking, composed^ and is undergoing such a revi-
sion from different Members of the Council, who have kindly un-
dertaken this task, as is calculated to make it as correct and complete
as the circumstances of the case will allow it to be. I have reason
to hope that this work will be shortly placed in the hands of the
Fellows, and that the example which it will present of what may be
accomplished by the exertions of a learned body wi^h very limited
funds at its command, will not be without its influence in hastening
the completion of a similar w ork with respect to our great national
library, upon a scale proportionate to its importance, and worthy of a
great and wealthy people, amongst whom literature, science, and
the arts are duly cultivated and pursued.

The discussions that have at different times during the last year
been raised upon the Minutes of your proceedings, constitute the
second subject which I wish especially to notice.

I am quite sure. Gentlemen, that you will agree with me in think-
ing, that no one circumstance has contributed so effectually to main-
tain the dignity of the Royal Society, as the prohibition of per-
sonal debate in the transaction of its ordinary business ; and if
I wished for any additional confirmation of this opinion, I would

144 Moj/al Societl/.

appeal to the very serious amount of irritation which it produced
amongst you in the course of the last year, though originating in
the most trivial causes. It was chiefly with a view to avoid incon-
veniences of this kind, and to provide an outlet for the proper ex-
pression of opinion, when any just occasion of complaint might
exist, or any extraordinary circumstance occur, and to terminate
disputes whenever unfortunately they might arise, that the Council,
at the last revision of our statutes, passed a by-law, as they were
fully authorized to do, which makes it imperative upon the President
and Council to call an extraordinary meeting of its Members, upon
the due presentation of a requisition for that purpose, signed by at
least six Fellows, and setting forth, in specific terms, the objects for
which it was required to be summoned, provided those objects be
not inconsistent with the charter and statutes of the Society. Such
extraordinary meetings being strictly domestic, and confined to the
Fellows of the Society only, appear to me not merely to offer a suf-
ficient security against any great mismanagement of the affairs of
the establishment, but likewise to protect your ordinary meetings
from those irregular and somewhat tumultuary discussions on mat-
ters of business, or personal conduct, which might otherwise be in
danger of arising.

I believe that many persons have expressed a wish that the regula-
tions of this Society should be so far relaxed as to allow, in conformity
with the practice of some other similar establishments, discussions
upon the papers, and those papers only, which are read before us ; I
confess, for my own part, that I am not at present prepared to accede
to this recommendation. A practice which has been sanctioned by
the usage of more than a century and a half, and found to be produc-
tive of scientific results unrivalled for their extent and value, should
not be abandoned by us without the most mature consideration ; and
though I am the last person to recommend a slavish submission to
the dictates or to the customs of antiquity, which may be unsuited
either to the altered circumstances of modern times, or incapable of
defence upon other and independent grounds, yet a reverence is
justly due both to maxims and observances which have been sanc-
tioned by high authorities, or connected with great and important
public benefits. It may be quite true that such discussions would
tend materially to increase the personal interest which is taken, by
many of our members, in our proceedings ; but when we consider
the abstract and abstruse nature of many of the papers which come
before us, and which no single reading can make perfectly intel-
ligible, even to the best-instructed hearer, as well as the vast variety
of subjects which they comprehend, I think we may fairly infer
that such discussions would rarely add much to the stock of facts
or of reasonings which they contain, or that their influence would be
materially felt in the publications of your Transactions, which have
always formed, and which ought always to form, the great object of
the foundation of this Society, and the only means by which its cha-
racter and influence can continue to be maintained unimpaired
throughout the civilized world. When we likewise take into further

Anniversary Address of the President, 145

consideration the irregularities and personalities to which such de-
bates would on some occasions give rise, unless very strictly li-
mited and very authoritatively controlled, as well as the indirect
influence which the premature expression of opinions upon the con-
tents and merits of individual papers might exercise upon the deci-
sion of the Council in selecting them for publication, you will be
disposed to agree with me, I trust, in thinking that such an experi-
ment would be at least dangerous to the peace, as it very possibly
might prove ultimately injurious to the scientific character, of the
Royal Society.

But let me not be misunderstood : the success that has attended
this practice in the institution which has contributed so powerfully
to the rapid advance of a highly popular science, might appear to
offer a practical refutation of such grounds of alarm as those which I
have ventured to suggest ; but the cases of the two Societies are
extremely different. The science of geology is eminently a science
of observation, where facts, collected from all quarters of the globe,
and accurately recorded, possess a value which is in many cases
independent of the theoretical inferences that may be deduced from
them : it is a science which disdains not the aid of the humblest
labourers who can widen the range of its observations ; it is a sci-
ence also in which both facts and theories can be communicated
more accurately and more rapidly by a graphic and vivid oral de-
scription, aided by an immediate reference to maps, drawings and
specimens, than by the most elaborate and laborious written descrip-
tions ; it is a science which can only be learnt by being seen, and
which can only be seen through ten thousand eyes. In all these,
and in many other important particulars, it differs from the majority
of those sciences which most commonly come under the notice of
the Royal Society; and the many circumstances which not only jus-
tify, but in some degree render necessary, the discussions upon the
papers read, or the facts communicated to the Geological Society,
would almost entirely cease to apply if extended to us. And when
we further consider the varied knowledge and accomplishments, the
lively wit and rare eloquence of many of those distinguished men
who usually take part in those debates, and who are themselves the
highest authorities in the very science which on such occasions they
are called upon to illustrate and to teach, we should be disposed
rather to regard them as lectures delivered by great masters to pu-
pils who come to learn, than as the discourses of philosophers,
amongst each other, upon the more abstract and less attractive de-
partments of human knowledge.

And now. Gentlemen, before I conclude this portion of my address,
there remains but one other point which I think it my duty to notice.
A trust of great importance, imposed on the President of the Royal
Society by the will of the last Earl of Bridgewater, the most onerous
and responsible duties of which devolved upon my worthy friend and
predecessor Mr. Davies Gilbert, is at length terminated, by the ap-
pearance, which has been long and anxiously expected, of the eighth
Treatise of the series. It would ill become me to speak of the mode

Third Series. Vol. 10. No. 59. Feb. 1837. U

146 Boyal Society.

in which that important duty was discharged by him, or of the prin-
ciples which guided himself and his distinguished assessors, in the se-
lection either of subjects or of the authors ; but a list which is headed
by the name of Whewell and closed by that of Buckland, can hardly
be considered as an unworthy representation of the science and lite-
rature of this country.

Amongst the losses sustained by the Society during the last year,
will be found many names of persons distinguished for their services
both in literature and in science ; and if we might be allowed to form
a judgement from the very great proportion of these eminent men
whose ages have approached the extreme limits of human life, we
might conclude with great confidence that the most severe studies
and the most trying climates, if pursued with temperance or guarded
against with care, are not unfavourable either to health or longe-
Tity. The list which has been placed in my hands contains the names
of twenty-one Fellows and two Foreign Members, and I greatly re-
gret that the notice which I am enabled to take of some of the most
distinguished of their number should be necessarily so slight and im-
perfect.

Mr. Pond succeeded Dr. Maskelyne as Astronomer Royal in 1810,
and retired from that important situation, under the pressure of many
infirmities, in the autumn of last year : he was formerly a member of
Trinity College, Cambridge, where he was a pupil of Professor Lax,
whose name appears also in the list of deaths which has been just
read to you. After leaving the University, he travelled in many
parts of the East, and particularly in Egypt, partly urged by the
spirit of adventure which is natural to youth and partly with a view
of making astronomical observations in climates more pure and more
regular than our own. After his return home in 1800, he settled at
Westbury, in Somersetshire, and devoted himself, amidst other pur-
suits, chiefly to astronomy, making use of a circular instrument of 2J
feet diameter, which had been constructed and divided by Troughton
with more than ordinary care. With this instrument he observed
by a peculiar method, the declinations of some of the principal fixed
stars, which were communicated to the Royal Society in 1806 ; and
it afterwards enabled him to establish the fact of a change of form
in the great quadrants at Greenwich, a discovery of great importance,
inasmuch as it not only led to the substitution of circular instru-
ments for them in our national observatory, but subsequently like-
wise to his own appointment as Astronomer Royal.

After Mr. Pond's establishment at Greenwich, he communicated
to the Royal Society from time to time, not merely the general re-
sults of his labours, but likewise his views of the theory of astrono-
mical observations and of the grounds of judging of their relative
accuracy : his system was to observe differences of declination and
right ascension, making every star a point of departure for the rest,
and considering the pole as a point in the heavens whose position
was capable of a determination, equally, and not more accurate than
that of any given star. To such a view of the theory of observation,
circular instruments were particularly adapted, and there is no reason

Anniversary Addness of the President. 147

to doubt that the relative catalogues of the stars which were formed
by Mr. Pond were more accurate and complete than those of any
preceding or cotemporary observer. Such a result, however, might
have been reasonably expected from the great powers and resources
of the establishment over which he presided and which he had him-
self been the chief means of calling into action.

The method which was adopted by Mr. Pond to determine the
limits of the annual parallax of certain fixed stars by means of fixed
telescopes of great focal length, was singularly ingenious and com-
plete. The existence and amount of such a parallax had been asserted
and assigned by Dr. Brinkley, in a Lyrae, a Aquilae, and a Cygni ;
but this opinion, although most ingeniously and even obstinately vin-
dicated and maintained by him, was, in the judgement of most other
astronomers, most decisively negatived by Mr. Pond, who showed
that the parallax of those fixed stars, supposing its amount to be
sensible, was confined within the limits of the errors of the most deli-
cate and perfect observations which have been hitherto made. There
is no great question in astronomy, the present position and limits of
which are more satisfactorily settled.

Mr. Pond was remarkable for his skill and delicacy in the mani-
pulation of his instruments, and no man was more capable of form-
ing a correct judgement of their capacities and powers, and of the
nature and ex,tent of the errors to which they were liable : he was in
the habit of placing great reliance on the results of a great num-
ber of observations, when no apparent or assignable cause existed for
giving a determinate sign or character to the errors of individual ob-
servations : this confidence, however, was founded on his great know-
ledge of the theory of observation, and was fully justified by a com-
parison both of his own results with each other, and with those of
other observers.

Mr. Pond was a man of gentle and amiable character, and singu-
larly candid and unprejudiced. His health for many years before his
death was greatly deranged, but he continued to struggle against the
progress of his infirmities, and, from a conscientious feeling, he never
abandoned the active duties of superintending the observatory, though
hardly able to sustain them. He died in August last, at Lee, in Kent^
and was buried in the tomb of his great predecessor Halley *.

Mr. Pond, though a great practical astronomer and a man of un-
commonly clear intellect and correct judgement, was deficient in one
very considerable qualification for the station which he filled, — I mean,

[• Various papers by Mr. Pond or relating to his observations and views
in Astronomy have appeared in the Philosophical Magazine. His paper
On Changes in the Declination of certain Fixed Stars, was reprinted from
the Phil. Trans, for 1823, in Phil. Mag., First Series, vol. Ixii. p. 175 ; the
subject is noticed also at pp. 391, 453, 454, and 466, of the same volume, in
which likewise will be found, at p. 292, Mr. P. 's memoir Oji the Parallax
of X LyrcB. In vol.lxvi. p. 33, appeared a translation of a paper by M.
Besscl respecting the former subject ; and a discussion relative to the ac-
curacy of -the Greenwich Observations will be found in vol. Ixiv. p. 367,
451, and vol. Ixvi. p. 292.— Edit.]

U2

1 48 Royal Society.

an acquaintance with the higher branches of Analysis, and their ap-
plication to Physical Astronomy. His successor, Gentlemen, is well
known to you, and needs no eulogium of mine ; but I cannot omit
the opportunity which is now offered to me of congratulating the
friends of astronomy and of science on the appointment of a gen-
tleman to this most important office, who is second to none in this
country in his great attainments in almost every department of accu-
rate science, in his indefatigable and systematic industry, in his high
sense of public duty, and in his profound knowledge both of physical
and of practical astronomy.

The names which I shall next bring before your notice are those
of three men, venerable alike for their great age and public services,
and who must always be regarded as entitled to hold a distinguished
place amongst that illustrious body of great men, who have been pro-
duced or brought forward by the important trusts, the varied employ-
ments, and, let me add likewise, the great rewards of our Indian empire ;
I mean Sir Charles Wilkins, Mr. Marsden, and Captain Horsburgh.

Sir Charles Wilkins went to India in 1770, and was the first
Englishman who thoroughly mastered the difficulties of the Sanscrit
language, of the classical works in which he published several
translations, and smoothed the obstacles to its attainment by a noble
grammar, which he composed for the especial benefit of the
students of the East India college at Hayleybury, of which he was
the oriental visitor and examiner from the period of its first esta-
blishment. He formed with his own hand the matrices of the first
Bengali and Persian types which were used in Bengal, and he was
the chief agent, in conjunction with Sir William Jones, in the esta-
blishment of the Asiatic Society of Calcutta, whose labours have
contributed so greatly to the advancement of our knowledge of the
languages and general condition of the provinces of our Eastern
empire. It is now more than fifty years since he returned to this
country, in possession of a competent fortune and vigorous health,
which he continued to enjoy, in conjunction with every social and
domestic comfort, with hardly any interruption, to the day of his
death. Sir Charles Wilkins was appointed, in 1 800, Librarian of the
great collection of Oriental MSS., which are preserved in the India
iHouse ; and this Society is indebted to him for the catalogue and
description of the Sanscrit and other Oriental MSS., which were
presented to it by Sir William and Lady Jones.

Sir Charles Wilkins w£is the father-in-law of Mr. Marsden,
though nearly his cotemporary in age. They went to the East about
the same time, and whilst one devoted himself to the study of the
languages and literature of the ancient and modern inhabitants of
continental India, the other availed himself of his position on the great
island of Sumatra and the Malayan peninsula, to gain a thorough ac-
quaintance with the present condition and past history of that activeand
adventurous race, whose character has been so deeply and so generally
impressed upon the languages and customs of nearly all the tribes who
inhabit the innumerable islands of the Indian Archipelago and of the
Pacific Ocean. His account of Sumatra, which appeared soon after his

Anniversay-y Address of the President, 149

return from the East, may be considered as a model for all monographs
of the history, languages, customs, and statistics of a particular
nation. He subseqifently published a Malay dictionary of great autho-
rity and value ; and in many separate memoirs, one of which appeared
the year before his death, he traced with great learning and research
the general characters and analogies of the East Insular and Poly-
nesian languages, and proposed an alphabet for their uniform and
intelligible transcription. Mr. Marsden was the author of four papers
in our Transactions on some remarkable natural phaenomena in the
island of Sumatra, on the Mahometan sera of the Hejira, and on the
chronological periods of the Hindoos ; the two last of which show a
very extensive acquaintance with Arabian and Hindoo literature. He
published very elaborate catalogues of his fine collections of voca-
bularies and grammars, and also of his oriental coins ; the first of
which he presented in his life-time to King's College, London, and
the second to the British Museum. Mr. Marsden returned to En-
gland from the East at an early age, and was Secretary to the Ad-
miralty during the most eventful period of the late war. He con-
tinued to enjoy to an extreme old age, extraordinary vigour both
of mind and body, equally respected and beloved for his great learn-
ing and very varied acquirements, for his independent and disin-
terested character, and for his many social and domestic virtues.

Captain James Horsburgh entered the sea service of the East India
Company at a very early age, and in a very humble capacity, and
raised himself by his perseverance, good conduct, and strong natural
talents to the command of a ship, in which he was employed, for a
considerable time, in a hydrographical survey of many of the coasts
and islands of the Indian and Chinese seas. It was soon after his
return to Europe in 1805, that he communicated to this Society,
through Mr. Cavendish, his very remarkable observations of the
equatropical motions of the mercury in the barometer when at sea* ;
and contributed along with Captain Flinders, both by these observa-
tions and by other directions which he subsequently published, to
make more fully known the importance of barometrical observations
at sea, as affording indications of great or sudden atmospheric
changes. Captain Horsburgh was soon afterwards appointed Hydro-
grapher to the East India Company, with the usual judgement^ and
discrimination of the Directors of that Body, in the selection and
rewarding of their officers ; and it was in this capacity that he pub-
lished not merely a great number of charts, but also " the East India
Sailing Directory," the result of the unremitting labour of many
years, and founded partly upon his own observations, and partly
upon a very accurate examination and reduction of the vast hy-
drographical records which are in the possession of the East India
Company ; forming altogether one of the most valuable contributions
that was ever made by the labours of one man to the interests of
navigation. Captain Horsburgh was the author of other works con-
nected with his favourite science, and he continued to devote him-

[* Capt. Horsburgh 's paper here referred to was reprinted in Phil. Mag.,
First Series, vol. xxiii, p. 289. — Edit.]

150 Royal Society.

self, until within a few days of his death, with almost unexampled
industry, to those pursuits which had formed, throughout his whole
life, the means by which he sought to benefit his countiymen and
mankind.

Mr. William Blane was the author of a paper in our Transac-
tions, written fifty years ago, on the production and preparation of
Borax, which is brought from Jumlat in Thibet, over the Himalaya
mountains into Hindostan.

Dr. David Hosack, of New York, was the author of a paper in
our Transactions, published in the year 1794. It related to the ex-
planation of the power which is possessed by the eye of adapting
itself to different distances, which he attributed to the action of the
external muscles of the eye, and not to the dilatation and contraction
of the iris, nor to the muscularity of the crystalline lens, by which its
convexity could be increased or diminished, a doctrine which had
been promulgated in a paper by Dr. Thomas Young, in the preced-
ing year. This subject is one of great interest, and has been very
frequently agitated ; and though an illustrious foreigner, M. Arago,
has recently defended the theory of Dr. Young with great ingenuity
and warmth, yet physiologists and anatomists are by no means agreed
on the adoption of this or any other single explanation.

Mr. John Bell was Senior Wrangler at Cambridge in 1786, and
a Fellow of Trinity College. Though labouring under physical dis-
advantages of no ordinary kind, and such as were apparently the
most adverse to success in the public exercise of his profession as a
lawyer, yet he conquered every difficulty and reached the highest
eminence by his great acuteness and strength of mind, his extensive
legal knowledge, and, not a little, likewise, by his sturdy integrity and
love of truth, which he respected, — a rare virtue — , even in advocating
the claims of a client. Mr. Bell, with an uncommon exercise of
philosophy, retired from the active duties of his profession, whilst in
the receipt of a splendid income from it, on the first warnings of
the approaches of the infirmities of old age. He was a man of great
liberality and kindness of heart, and remarkable for the steadiness
of his attachment to a large circle of professional and other friends.

The Rev. William Lax, formerly Fellow of Trinity College, and
Lowndes's Professor of Astronomy and Geometry in the University
of Cambridge, was Senior Wrangler in the year preceding Mr. Bell,
and throughout life one of his most intimate friends : he contributed
two papers to our Transactions; one in 1796, on a subject of no
great importance, and the other in 1809, on the method of ex-
amining the divisions of astronomical instruments, in the same vo-
lume which contained papers on similar subjects by Mr. Cavendish
and Mr. Troughton. The method proposed by Mr. Lax, though
very ingenious, requires great labour and time, and is inferior in
accuracy and efficiency to that which was adopted by Mr. Troughton
for tabulating the errors of the primary divisions of circular instru-
ments. Professor Lax was the author of Tables to be used with the
Nautical Almanack, and he had built a small observatory at his re-
sidence in Hertfordshire, where he occupied himself for the last

Atifiiversary Address of the President. 151

thirty years of his life with studies and pursuits connected with the
advancement of astronomy.

Sir John Sinclair devoted nearly the whole of a very long and
laborious life to pursuits and inquiries connected with the improve-
ment of agriculture and the general benefit of his countrymen. He
was a very voluminous author ; and though different opinions may
be entertained of the merit and usefulness of some of his later pro-
ductions, the Statistical Account of Scotland which he originated,
and arranged, will be a durable monument to his memory, pre-
senting as it does a more complete and comprehensive record of the
state of that kingdom at the period when it was compiled, than is
to be found in the literature of any other country.

Dr. John Gillies, venerable alike for his great age and his amiable
character, was the successor of Dr. Robertson, as the king's histo-
riographer for Scotland: he was the author of a History of Greece
and of the World from the conquests of Alexander to the age of
Augustus, and he translated some of the Greek orators, the ethical,
political and rhetorical treatises of Aristotle, upon whose specu-
lative works generally he wrote a very enlarged commentary. He
was a pleasing and popular writer, though not very profoundly ac-
quainted with the great advances which have been made of late
years in Germany and elsewhere in our knowledge of archaeology
and historical criticism.

Sir William Gell was well known as a topographical antiquary,
and published works of great interest and research, some of them
very splendidly embellished, on Pompeii, and on the modern, as
illustrating the ancient topography of Troy, Ithaca, the Pelopon-
nesus, Attica and Rome. He was a very accomplished artist and a
man of great liveliness of conversation, and of very attractive man-
ners. Sir William Gell was formerly Fellow of Emanuel College,
Cambridge, and was attached, for some time, in the quality of Vice-
chamberlain, to the late Queen Caroline. He spent the later years
of his life, a victim to the gout and other infirmities, at Naples, in
the neighbourhood of those remarkable ruins which he had so care-
fully and so beautifully illustrated, and which continued to supply
him, from day to day, with fresh objects of interesting inquiry.

Dr. Warren, though one of the most distinguished physicians in
this metropolis, contributed very little, by his writings, to medical or
general literature : he was considered to be an accomplished classical
scholar, and a man of very extensive acquirements : he was a
strenuous vindicator of the character and independence of his pro-
fession, and though his manners were somewhat abrupt, and some-
times apparently uncourteous, yet he was a man of very warm
affections, and greatly beloved and respected by a large body of
friends.

Those to whom Dr. William Elford Leach was known in his happier
days, when in the full enjoyment of health and reason, can best ap-
preciate the great loss which the natural sciences and our national
museum sustained by that melancholy visitation, which, like the
hand of death, terminated his scientific labours. His enthusiastic

152 Royal Society,

devotion to his favourite studies, his great knowledge of details,
combined with no inconsiderable talents for classification, were
eminently calculated to raise him to the very highest eminence as an
original and philosophical naturalist. Though his career of research
and discovery was prematurely cut short, yet we are chiefly indebted
to him for the fii-st introduction into this country of the natural
system of arrangement in conchology and entomology, and for the
adoption of those more general and philosophical views of those
sciences which originated with LatreilU) and Cuvier. Dr. Leach was
the author of a paper in our Transactions on the genus Ocythoe,
to prove that it is a parasitical inhabitant of the Argonaut. He wrote
several memoirs in the Linnaean Transactions ; an excellent treatise
on British Malacostraca : and he also contributed largely to the
Zoological Miscellany, to Brewster's Encyclopaedia and to the French
Dictionnaire des Sciences Naturelles, He died of an attack of
cholera on the 25th of August last, at the Palazzo St. Sebastiano, in
the province of Tortona in Italy.

The last name which occurs in the melancholy list of our departed
compatriot associates, is that of Dr. William Henry, to whom the
science of chemistry generally, and of gaseous chemistry in parti-
cular, is under great obligations. He was the author of nine papers
in our Transactions, many of them of great merit* ; and his System of
Chemistry is one of the best written and beet arranged compen-
diums of that important and extensive science, which has been pub-
lished of late years, whether in our own language or in any other.
The Memoirs of the Manchester Society are chiefly indebted to
him, in conjunction with Dr. Dalton, for the high character which
they have so long maintained. Dr. Henry, like Dr. Wollaston, made
the results of science, obtained by the most original and diffi-
cult researches, the foundation of a splendid fortune, and few persons
have contributed more effectually, by their discoveries and exertions
to the promotion of those arts and manufactures which form the
foundation of the prosperity of a great commercial nation.

The names of the Foreign members whom the Society has lost
during the last year are, Andre Marie Ampere and Antoine-
Laurent de Jussieu, both of them members of the Academic des
Sciences de France.

Mons. Ampere was born at Lyons in 1775, and made his first
appearance in the scientific world in a short work which showed con-

[* Of tiiese nine papers by Dr. Henry in the Philosophical Tr<an suctions,
seven have been given entire in the Philosophical Magazine, together with
an abstract of another. Dr. H.'s Account of Experiments to decovipose
Muriatic Acid, will be found in Phil. Mag., First Series, vol. vii. p. 211 ; an
abstract of his paper on the Absoi-ption of Gases by Water, (from the pen,
we believe, of Sir H. Davy,) in vol. xvi. p. 89 ; his Description of an Appa-
ratus for analysing Inflammahle Gases, with Experiments on the Gas from
Coal, in vol. xxxii. p. 277 ; Experiments on Ammonia, in vol. xxxiv. p. 3G9 ;
Analysis of British and Foreign Salt, in vol. xxxvi. p. lOG ; Additional Ex-
periments on Muriatic Acid, in vol. xl. p. 337 ; On the aeriform compounds
of Charcoal and Hydrogen, in vol. Iviii. p. 90 ; and On the action of finely
divided Platinum on Gaseous Mixtures, in vol.lxv. p.2G9. — Edit.]

Annhnsanj Address of the President, 153

siderablc command of analysis, entitled Considerations sur la Theorie
Mathematique du Jeu-, in which the question of the safety of habitual
and indefinite play, either against a single person of greater fortune,
or indifferently against any number of persons, even when the game
is perfectly fair and equal, is discussed and solved, and its result ex-
hibited in a form full of warning to those by whom gaming is pur-
sued as an occupation, in which success or failure is considered as
the gift of fortune, and not the inevitable result of calculation.
M. Ampere was subsequently appointed Professor of the Poly-
technic School, and published memoirs on the integration of
partial differential equations, and on other subjects, which show
a profound knowledge of some of the most refined and difficult
artifices of analysis: to him likewise we are indebted for mcs
nioirs on the Mathematical Theories of Electro-magnetic Cur-
rents, which are remarkable for the skill and ingenuity with which
the powers of analysis are brought to beai^ on subjects apparently
the most remote from their operation. His inquiry into the equa-
tion of Fresnel's wave surface is more remarkable as an example
of resolute perseverance than of success, and his last work, on the
Philosophy of the Sciences, showed him to be much less happj'"
in his metaphysical, than in his physical and analytical speculations.
M. Ampere was a man of great simplicity of character, and his ex-
traordinary fits of absence of mind w^ere not unfrequently made the
subject of much innocent amusement. He took no part in the cabals
and jealousies which too frequently disturb the peace of the world
of science, and he was universally respected and beloved for his
great integrity and the kindness of his affections.

Antoine-Laurent de Jussieu, a name singularly illustrious in the
annals of botanical science, was born at Lyons in 1748. He was
nephew to the great Bernard de Jussieu, under whose auspices he was
first introduced into the scientific world of Paris, and appointed, at a
very early age, demonstrator of botany in the Jardin du Roi. After
this appointment, though originally destined for the profession of
medicine, he devoted himself almost exclusively to the study of
botany, more especially with a view to the establishment and de-
velopement of the natural system of arrangement, a very bold and
successful approximation to which had been effected by his uncle in
the distribution of the plants in the Garden of the Trianon.* He
succeeded his uncle as administrator of the Jardin desPlantes in 1779,
and published two memoirs of great originality and importance on
the relative value of characters in the distinction of the genera and
orders of plants. In tlie year 1789 he published his great and truly
classical work entitled Genera Plantarum secundum Ordines na-
turales disposita, which caused a total revolution in the science of
botany. To the modification and extension of the views contained in

* This arrangement, made in 1759, is given by his nephew at ihe conclusion of

his introduction to his great work, published in 1789 : though extremely imperfect
and in many respects erroneous, it was founded upon just principles, and was in
almost every respect superior to those which had been proposed by Linna-us and
by Tournefort. [See our last number, p. 3S. — Edit.]

Third Series. Vol. 10 No. 59. Feb. 1837. X

IBIe InfelU^ence and Miscellaneous Artides.

that work, rendered necessary by new ol>servations and by tlie vast
accession of new genera and orders, brouglit from the tropics.
South America, Australia, and elsewhere, he devoted the remainder
of his life. His later memoirs, many of which are of great value, ane
chiefly contained in the Amiales, and sul>sequently in the Memoires
du Musetmi d Histoire Naturelle. M. de Jussieu was a man of very
simple manners and amiable character, of a social and aflectioiiate tem-
per, and a perfect stranger to scientific jealousies and intrigues. He
attained to an extreme old ago, and had the happiness of witnessing
the almost universal adoption of that system of botanical arrange-
lUfcnt, tlie estaWishment of which had formed the great object of the
laboui-s of his life.

M,

XXXI. Intelligence and Miscellaneous Articles,

€>N THE REDUCTION OF METALS BY ELECTRICITY.

BECQUEREL, on presenting some electro-chemical appa-
• ratus to the Academic Royale des Sciences of Paris, by the
aid of which he bad been able to effect the immediate reduction of sil-
ver, lead and copper,stated that, without the intervention of mercury,
by constructing an electro-chemical apparatus with iron, a saturated
solution of common salt, and an ore of silver, properly prepared, he
had extracted from the latter the silver which it contained, under the
form of crystals. The minerals on which the experiments were
made were the ores raised in Columbia and the ore of Allemont.
The same method has also been successfully employed to extract
from the copper pyrites of Chessy, near Lyons, the silver which
it contains, without affecting the copper. It is only from the ar-
gentiferous galenas that it is difficult to extract the silver. When
a mineral like that of Aliemont contains many metals, as lead,
copper, &c., each of these metals is separately reduced and at dif-
ferent times, so that the separation is easily effected. From this it
results that the ores of lead and copper may be treated in the same
manner as those of silver, but with much less facility, because of the
different degrees of oxidation which they acquire, and the com-
pounds which they form during roasting. M. Becquerel is at pre-
sent occupied with further researches on the extraction of metals,
but deeme.l it proper, for the interests of science, to make known
to the Academy the principle by means of which he had been able
to extract some metals, particularly silver, from their respective
ores.-^Vlustitiity Mars 2, 1836.

ON A SIMPLE METHOD OF OBTAINING SPONGY PLATINA.

To obtain spongy platina, M. Dobereiner fuses crude platina with
twice its weight of zinc, and treats the alloys, when powdered, first
with dilute sulphuric acid, and then with nitric acid also diluted, to
oxidize and dissolve all the zinc, which, contrary to theory, takes
place but slowly, even with heat : there is thus obtained an insolu-
ble greyish black residue of finely divided but impure platina, which,

latclligcnce and Mi scellaneoiis Articles, 13-5

wlien properly purified by a solution of potash and water, acts like
spongy platina, and possesses such remarkable oxidizing properties,
that ic not only converts formic acid into carbonic acid, and alcohol
into acetic acid, but even the osmium which it contains into osmic
acid. This latter is soon formed when the powder of platina is dried,
and may be separatelj^ obtained by distilling the platina with a little
water. It is immediately reduced by alcohol, and consequently is
not obtained amongst the products of the oxidation of this liquid.

This method, recommended thirty years sir^ce by Descotils, is
an excellent one for the preparation of platina in a state of minute
division, and is chiefly applicable in working large masses of native
platina like tiiose of the Oural, and also for the preparation of the
jjpongy platina employed for absorbing oxygen and for the juoduc-
tion of acetic acid. — jQur. de Pharnmcie, July 1836.

-ON THE DECOLORIZING COMBINATIONS OF CHLORINE.

M. Martens, in a former memoir on this subject already published,
offered experiments and arguments which tended to show tliat the
decolorizing chlorides ought to be regarded as feeble comi)iniitions
of chlorine and basic oxides. Sonie short time after this M. Balard,
of Montpellier, again raised a doubt on the question, and by his
discovery of hypochloroiis acid and of decolorizing hypochlorites,
appeared to have proved that the opinion M. Martens had advo-
cated was incorrect ; that is to say, according to M. Balard, these
bleaching compounds ought to be considered as mixtures of hypo-
chlorites and chlorides, agreeably to the hypothesis of Berzelius.
Returning to this first memoir and comparing the propjTties of
hypochlorites with the decolorizing chlorides, M. Martens has ar-
rived Ht results which, in his opinion, do not permit us to confound
the two compounds, and which serve to confirm the former view
of their composition as chlorides of oxides. We now proceed to
the principal facts contained in the present memoir, and which
the author considers he has established by his experiments.

1st. The binoxide of chlorine of some chemists must be consi-
dered as an acid under the name of chlorous acid : it forms com-
pounds with the compound alkaline oxides (oxides alcalins com-
poses (alkalis ?)), which may be called chlorites, and which are de-
composed by almost all the acids, with effervescence and disen-
gagement of chlorous acid.

2nd. The chlorites may be obtained in the solid state by evapo-
ration, without decomposing, taking care that they have excess of
base, or, rather, that they possess an alkaline action. When they
are saturated so as to indicate neutrality with litmus paper, their
solutions, when they are concentrated or evaporated, are decom-
posed into chlorates and chlorides, like the chlorides of oxides,
with the difference of affording in proportion much more chlorate
than the latter.

3rd. The chlorites possess an extremely powerful decolorizing and
oxidizing action, like the chlorides of oxides and the hypochlorites
of M, baJard. Thpse which are not saturated with chlorous acid

X2

156 Litelligence and Miscdhmeons Articles,

do not destroy colour, except by tlie intervention of an acid, but
the others decolorize instantly, like free chlorine.

4th. The chlorites, even when mixed with metallic chlorides,
possess all the characteristic properties which distinguish them from
the decolorizing chlorides of oxides ; and, amongst others, that of
the disengagement of chlorous acid, on the addition of acids, instead
of chlorine, which, under these circumstances, is evolved from the
chlorides of oxides.

5th. The chlorites are analogous to the hypochlorites of M.
Balard as regards their decolorizing and oxidizing power, but are
much more stable.

6th. Although the hypochlorites, mixed with metallic chlorides,
disengage only chlorine by the addition of acids, as M. Balard has
rightly observed, and are in this respect analogous to the decolor-
izing chlorides of oxides, it need not necessarily be inferred that
their chemical constitution is the same, since hypochlorous acid
itself, acting on a metallic chloride, evolves only chlorine. We may,
moreover, compare this phjenomenon to that of many other ana-
logous chemical actions, and, amongst others, to the fact stated
long since by Gay-Lussac, that a mixture of iodate and iodide of
potas^sium, when acted on by even the weakest acids, disengages
iodine ; that also which is presented to us by a mixture of chlorate
and chloride of potassium, whic h readily decomposes with the si-
multaneous evolution of chlorous acid and chlorine, by the ac-
tion of acids so much diluted that they had no action on either of
the compounds of the mixture taken separately. All these actions
may be easily represented and explained by atoniic formulae,

7th. By dii'tilling the chlorides of soda and potash supersaturated
with chlorine, hypochlorous acid is produced, the residue being a
neutral metallic chloride. This is a new and simple method of ob-
taining this acid, which has hitherto only been obtained by the ac-
tion of certain insoluble metallic oxides on chlorine with the inter-
vention of water.

8lh. Red oxide of mercury does not present so many advantages
for the preparation of hypochlorous acid, because it may form an
insoluble oxichloride, which renders the chloride of oxide of mer-
cury, though easy to obtain, unstable, and readily causes its con-
version into hypochlorous acid and an insoluble oxichloride j so
that this chloride of an oxide may give rise to hypochlorous acid
without heing supersaturated with chlorine.

9th. The dec(^lorizing chlorides of potash and soda, when they
have excess of base, may be evaporated without decomposing, and
even heated to 212° Fahr., without losing their decolorizing power,
which is not the case with the hypochlorites, and indicates a differ-
ent composition.

10th. The production of hypochlorous add, by the distillation of
the chlorides of potash and soda, supersaturated with chlorine with-
out an alkaline residue, can be but little understood by the hypo-
thesis that these decolorizing chlorides consist of hypochlorites
mixed with metallic chlorides, although it may be easily deduced

Intelligence and Miscellaneous Articles, 157

from the composition originally assigned to the chlorides of oxitles.
— LV;w//M Juillet 13, 1836.

ON THE ACTION OF ANHYDROUS SULPHURIC ACID ON SOME
METALLIC CHLORIDES.

M. Rose, in the course of his memoir, notices the researches of
L. Gmelin, which have shown tliat anhydrous sulphuric acid decom-
poses common salt in a very <lifterent manner to what the hydrated
acid does, for although the first converts it into sulphate of soda
like the second, yet in the first case the sodium is oxidized at the
expense of the sulphuric acid, and during the decomposition sul-
phurous acid is disengaged along with chlorine. M.L. Gmelin, and
after him MM. Sertiirner and Dobereiner, made all their experi-
ments by directingthe vapour ofanhydrous sulphuric acid upon heated
common salt. The result is, however, very different when the va-
))our of the anhydrous acid is passed over chloride of sodium finely
powdered and placed in a vessel which is kept cool by a freezing
mixture. In this case the acid vapour is rapidly absorbed by the
metallic chloride without deconiposing it. The whole is converted
into a transparent mass, which is at firfct soft, but hardens by de-
grees; it emits no fumes, not affording the slightest traces of hy-
drochloric acid, of chlorine, nor of sulphurous acid. This ma^s,
which is composed of anhydrous sulphuric acid and chloride of
sodium, deconiposes when heated, and is converted into sulj)hate of
soda, with the disengagement of chlorine and sulphurous acid g;is.

The chloride of potassium and hydrochlorate of ammonia act in
the same manner with the vapour of anhydrous sulphuric acid as
common salt, except that the ammoniacal salt absorbs it with ever*
greater rapidity than the other two. U we heat the compound
formed by the salammoniac and the anhydrous acid, hydrochloric
acid gas is at first disengaged, and afterwards the phaenomena occur
which accompany the sublimation of sulphate of ammonia.

If these compounds of anhydrous sulphuric acid and a chloride^
are moistened with a few drops of water, abundance of hydrochloric
acid gas is immediately disengaged, and when also they are exposed
to a damp atmosphere they immediately begin to decompose, with
the evolution of tho same gas.

All the metallic chlorides do not equally unite with anhydrous
sulphuric acid ; thus, it cannot be combined with the chlorides of
barium and copper in their anhydrous state. On the contrary, an-
hydrous sulphuric acid unites with some equally anhydrous salts ;.
a.nongst others, with the nitrate, and even, although slowly and with
difficulty, with tiie sulphate of pota»>h. The most important of these
compounds is that of anhydrous acid, with sulphate of ammonia,
likewise anhydrous, which is always simultaneously formed in the
preparation of these latter salts*, and which prevents us obtaining
them pure and in quantity. — Jour, de C/iimie Mcdicale, Oct., I8'i(i*.

* So in the French.

158 Intelligence and Miscillancotts Articles,

ARTIFICIAL FORMATION OF CRYSTALLIZED IRON PYRITES.

This process of M. Wohler consists in slowly heating in a glass
flask, or other convenient vessel, peroxide of iron, sulphur, and hy-
drochlorate of ammonia, intimately nnxed, until all the ammoniacal
salt is sublimed, suffering the mass to cool slowly, and afterwards
washing with water ; there will be found at the bottom of the vessel
heavy octohedra and tetrahedra, of a yellow colour, which are iden-
tical with the conimon crystallized pyrites. The larger the mai^s of
the materials employed, the larger and more perfect are the crystals
obtaine<l. — Jour, de Pharmacie, Oct., 1836.

ON THE DEGREE OF COLD PRODUCED BY SOLID CARBONIC

ACID.

M. Thilorier has invented an apparatus of a very simple con-
struction, (which, however, we regret to say, is not described,) by
which raas'Cs of from two to three hundred grains of solid carbonic
acid can be quickly and oecononiically obtained.

The acid obtained by this apparatus resembles compact snow. In
his former experiment on the degree of cold produced by this sub-
stance, the author directed a jet of liquid carbonic acid on the bulb
of a thermometer, &c., but the facility with which the solid acid is
now obtained in abundance has allowed M. Thilorier to use a pre-
ferable method of manipulation. The bulb of a thermometer was
placed in the midst of a small portion of solid carbonic acid, and at
the expiration of about two minutes the thermometrical index be-
came stationary, having sunk to — 162° Falir. A few drops of aether
or alcohol poured on the solid acid do not indicate any appreciable
alteration o^ temperature. The aether forms a half liquid mixture
of about the consistence of melting snow ; but the alcohol, uniting
with the solid acid, congeals, forming a hard, brilliant and semi-
transparent ice. This congelation of anhydrous alcohol does not
occur unlej^s it is mixed with the acid, for when the alcohol is
poured into a silver tube, and this plunged into solid carbonic acid,
no change is produced.

The mixture of alcohol and solid carbonic acid begins to melt at
— 153° Fahr., and, commencing at this point, the temperature docs
not vary ; thus affording at this extremity of the thermometric scale
a point as invariably fixed as that indicated by melting ice.

When 1.30 or 180 grains of mercury are placed on a small and
concave portion of solid carbonic acid, it solidifies in the course of
a iew seconds, and continues so as long as any solid carbonic acid
remains, that is, fur 20 or 30 minutes, when the weight of the acid is
about 110 grains.

Although the addition of aether or alcohol does not increase the
degree of cold, yet it enables the solid acid to moisten, and to ad-
here more closely to, the surfaces of bodies, thus greatly increasing
its refrigerating power. A portion of carbonic acid, on the addition
of a fQw drops of alcohol or aether, will solidify from 15 to 20 times
its weight of mercury, thus affording an easy and elegant method, far
superior to any ycl used; for ihc solidification of mercury.

Meteorological Observations, 159

The specific gravity of liquid carbonic acid is so variable tbat,
from 32*^ to 86° Fahr., it runs through the scale of density from
water to the aethers. Its dilatibility, the pressure and weight of its
vapour, are four times greater than that of atmospheric air; its ca-
pillarity, and particularly its compressibility, are a tlrousand times
greater than that of water. From these.faCts the author has been led
to a uniform and constant law, by which he connects phsenomena
which at first sight seem to be quite independent of each other, —
V Institute Oct. 5, 1836.

MELLITIC ACID.

MM. Liebig and Pelouze, in endeavouring to determine the com-
position of mellitic acid, made some experiments on the salt it
forms with oxide of silver, which have led them to think that this
acid should be considered as a hydracid, their experiments confirm-
ing in this respect the views of M. Dulong on oxalic acid.

Mellitate of silver dried in vacuo over sulphuric acid contains hy-
drogen, which it does not lose at a temperature below 356° Fahr. j
it is then expelled as water, and the salt changes its colour. This
is the case with no other salt of silver, as they are all anhydrous.
In this case the formation of water seems to be owing to the reduc-
tion of the oxide, and not to a simple volatilization of water existing
in the salt. According to known analyses, mellitic acid contains 3
equivalents of oxygen. MM. Liebig and Pelouze, however, sup-
pose it contains 4 of oxygen and also 1 of hydrogen ; that this hy-
drogen enters into the constitution of all the raellitates, except mel-
litate of silver, which has been heated to 356°, regarding this last
salt as a compound of metallic silver with the radicle of the hy-
dracid— Vlnstitut, Oct. 5, 1836.

METEOROLOGICAL OBSERVATIONS FOR DECEMBER 1836.

Chistvick, — Dec. 1, Foggy. 2. Rain : stormy. 3. Rain. 4. Overcast :
rain at night. 5. Overcast : clear. 6. Cloudy and fine. 7. Stormy showers.
8. Showery: clear with lightning at night. 9. Cloudy and cold. 10. Clear
and frosty : slightly overcast. 1 1. Slight fog: rain. 12. Rain : stormy at
night. 13, 14. Cloudy and cold. 15, 16. Fine. 17. Slight frost ; over-
cast. 18, 19. Fine. 20 — 22. Foggy. 23. Cloudy. 24. Clear and cold.
25 — 27. Snowing and stormy. 28. Overcast. 29. Snowing. 30. Hazy :
snowing : cloudy and cold. 31. Hazy : cloudy and cold.

The heavy snow storm, which, at London, commenced on the 25th, is
perhaps the most remarkable of any recorded at the same period of the
season. It appears to have been general, not only over Britain, but also
over a great part of Europe. A fall of snow is mentioned as having been
experienced at Bilboa in Spain, on the night of the 24th. — R. Thompson.

Boston.— Dec. 1. Fine. 2. Cloudy. 3, 4. Fine. 5. Rain. 6. Fine.
7, 8. Fine : ruin early a.m. 9— 1 1 . Fine. 1 2. Cloudy : rain a.m.

13 — 15. Fine. 16. Fine: rain early a.m. 17. Fine. 18, l9. Cloudy.
20 — 23. Fine. 24. Cloudy : snow r.M. 25. Fine : snow a.m. and p.m.

26. Snow. 27. Cloudy. 28. Snow. 29. Cloudy. 30. Snow. 31. Cloudy:
melted snow.

N.B. The 24th, 25th and 26th an immense fall of snow, which was
drifted in some places ten feet deep. The mail twenty hours behind the
usual time. — S. Veall.

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THE

LONDON AND EDINBURGH

PHILOSOPHICAL MAGAZINE

AND

JOURNAL OF SCIENCE.

♦ '

[THIRD SERIES.]

MARCH 1837.

T'

XXXII. Notice of a Vein of Bituminous Coal in the Vicinity
of Havana^ in the Island of Cuba. By Richard Cowling
Taylor, Esq,^ F. G.S., and Thomas G. Clemson, Esq,^

'HE substance of the following article was recently read
to the American Philosophical Society, and its authors
are desirous of extending a knowledge of its details by means
of the Philosophical Magazine.

The bituminous coal mine of Casualidad is situated about
three leagues east of the city of Havana, and on a main road
(CaminaReal) leading to the city of Guanabacoa, from which
place it is distant six miles, and from the sea, at a place of
embarcation, only two miles.

From Guanabacoa eastward, the surface of the country is
undulating, and partakes of those characters which are so
marked elsewhere in this island, where the serpentines and the
euphotides are the predominant rocks. In leaving Regla, on
the south side of the bay of Havana, the euphotides, — which
Baron von Humboldt has described here, and which we
found also to exist with similar characters in the district of
Holguin, and for many miles throughout the long chain of
barren savanas which stretch along the north-eastern portion
of the island, and contain fine veins of copper, — are here evi-
dentlv the most prevailing rocks. They occupy a breadth of
about two leagues, within which area the city of Guanabacoa
and the adjacent petroleum springs are situated.

When within half a mile of the coal vein in question, a

* Communicated by the Authors.
Third Series. Vol. 10. No. 60. March 1837. Y

162 Messrs. R. C. Taylor a7ul T. G. Clemson on

fragile, dirty-gray- coloured, argillaceous rock succeeds to the
serpentine and alternates with the euphotides.

Towards Giinnabacon, and indeed throughout a large por-
tion of the island of Cuba, the prevailing course or strike of
the rocks is about east and west; but in the vicinity of the
coal we unexpectedly found that the direction changed to
north and south.

The coal vein of Casualidad is visible at opposite extremities
of an excavation thirty feet deep, of a quadrangular form,
descending on one side by steps cut in the soft rock or clay
which bounds the coal on either side. This soft rock is fra-
gile, incoherent, distorted, of a yellowish green colour, like
the prevailing euphotides, of which it is a variety. A few
feet to the eastward of the vein there occurs a hard blue sili-
ceous rock, containing small cavities that are partially filled
with a leek-green mineral which we conceive to be a variety of
serpentine.

In close connection with the above, a beautiful diorite oc-
curs, the base of which is petrosiliceous, tinged with green,
which colour is caused by a mixture of serpentine. This
rock is very hard, and has a highly crystalline stiucture. It
crops out at several points

The siliceous rock, the diorites, and the euphotides alter-
nate the one with the other. The two first mentioned are in
much less proportion than is the third, which is by far the
most predominant rock of the country.

All these are highly inclined, and frequently are vertical ;
their direction, as before stated, being north and south, in the
neighbourhood of the mine.

Appearance of the Coal Vein. — The vein commences or
crops out immediately under the thin alluvial soil of the sur-
face, and follows an irregular, but nearly perpendicular direc-
tion downwards, so far as it has been traced, and as shown in
fig. 1.

It is visible to the depth of full thirty feet; but the bottom
of the excavation being covered with mud, which had been
washed in during the rainy season, we could not readily define
the breadth of the vein there ; but it was stated by the over-
seer to be nine feet thick. From even this small opening
many tons of pure coal had been extracted, and were deposited
in a large building adjacent.

On the north side of the excavation the vein is solid ; having
a thickness gradually increasing to four feet at the depth of
twenty feet. The coal lies in parallel horizontal layers, of
from one to four inches in thickness, across the vein. Some-
times these layers appear to have their horizontal position par-

a Vein of Bituminous Coal in the Island of Cuba. 163

tially disturbed, particularly near the outer edges, in which
case they were slightly curved. Where an accidental derange-
ment of the vein has taken place, this curving up of the outer
edges or extremities of the planes of stratified bituminous
matter is particularly observable. Near the walls of the vein*
the laminee of the coal for a few inches in depth are deflected,
as if they had been pressed by the sides or walls. Here the
structure becomes bacillary, and the coal on the slightest
effort divides into irregular polyhedrons. The surface of this
coal, when detached from the walls, instead of being smooth
or covered with any kind of bituminous shale, is rough, and
presents a bacillo-fibrous appearance, similar to the structure
observed in arragonites and other fibrous minerals. Two oc
three small branches oxjilons are seen passing from the main
vein at about the depth of twenty feet, occupying small fissures
in the surrounding rock. These branches all rise towards the
surface, but at different angles.

Fig. 1.

Section of the Coal Vein to the depth of 30 feet at the Mine of Casua-
Jiclad, in the Island of Cuba, 10 miles east of Havana.

4 Feet.

On the south side of the opening the coal, in rising towards
the outcrop, parts oflf'into two separate veins, longitudinally,
for an uncertain space ; and is apparently more disseminated
through this rock than on the north side.

With regard, therefore, to the mine of Casualidad, we have
Y2

164 Messrs. R. C. Taylor mid T. G. Clemson on

here, in the strictest sense of the term, a coal vein, unlike
any we have before witnessed in any part of the world. It is
distinguished from the ordinary deposits of coal, in as much
as those occur in distinctly stratified beds, and almost inva-
riably exhibit abundant traces of organic remains, for the most
part of vegetable origin ; whereas we have before us a geo-
logical phaenomenon of no common occurrence, yet whose
origin seems sufficiently intelligible. It was evidently, ori-
ginally, an irregular open fissure, terminating upwards in a
wedge-like form ; having various branches, all of which have
been subsequently filled with carbonaceous matter, as if in-
jected from below, and that not by slow degrees or by an in-
finite succession of depositions, but suddenly and at once.

This coal is wholly unaccompanied by traces of vegetable
remains, or by those beds of bituminous or other shales which
almost invariably envelop, cover, or accompany ordinary coal
seams, whether in secondary or transition formations. The
layers or transverse seams of which we have spoken appear
to maintain a horizontal position, that is to say, at right angles
to the vein, and when otherwise, the result is accidental, or
produced by an after cause. This fact, together with the
bacillo-fibrous structure observed, where the coal is in contact
with the walls, are among the reasons which lead us to lean
towards the supposition that the fissure was charged or filled
at once, and that these characteristics are the result of the
carbonaceous matter having passed to a more solid state in its
present position.

It would be rash to pronounce an opinion on the presumed
extent of this deposit, or to speculate on the probable magni-
tude of the vein, below the point at which it is visible at the
depth to which we have had access. But if the vein continue
to enlarge downwards, in the same proportion as it has aug-
mented in the first thirty feet, or even if it holds the present
breadth of nine feet, the quantity of this mineral must be very
great, and will prove a highly acceptable discovery, so near
the precincts of a great and flourishing city, so convenient to
the Embarcadero on the sea-coast, and in the midst of a di-
strict from which nearly all the timber for fuel has been long
since removed.

Qiiality, — This coal is unusually, light, its specific gravity
being commonly not more than 1'142. Two experiments upon
heavier specimens, (for the density is by no means uniform,)
gave 1189 and 1-197.

It is perfectly jet black ; having a resplendent lustre, which
is much greater in one direction, or under one aspect, than in
the other; and it divides into parallel layers in the mass. The

a Vein of BLuminous Coal in the Islafid ofCitha, 165

surfaces of the divisions or partiiifrs of the coal are brilliantly
shining. Its cross fracture is rough, and has a glimmering
pitchy appearance.

We have now to advert to an external character which is
very common, and which, in fact, is of constant and universal
occurrence in this combustible; a feature which distinguishes it
from all other coals which have come to our knowledge in
any (juarter of the globe. Its horizontal fracture or surface is
marked, as shown in figure 2, by numerous concentric, or,
more properly speaking, excentric rings of various sizes, from
a twentieth part of an inch to a foot in diameter. They are
perfectly regular and uniform in shape, smooth, shining, con-
choidal, resembling the impressions made by a seal in black
wax, or when first seen, appear like the casts of the flat valves
of some shells. i

This coal is exceedingly Fig. 2.

friable, breaking into small Form of thelmpressions on the laminae
fragments under the ham-
mer. Its powder is brown,
and when pressed under the
pestle, takes a polish, like
certain resinous substances.
It burns with much flame
and a great deal of smoke ;
melts, and gives a light vo-
luminous cake, which, when
incinerated, leaves compara-
tively a small proportion of
cinders or ashes.

The following analysis,
which was made by one of us,
gave per cent, as follows :

Volatile matter (gas, &c.) 63*00

Carbon \ 34-97

Ashes and cinder 2*03

of the Coal of Casualidad.

100-
The foregoing examination of this bituminous coal (for we
see no reason to separate it from combustibles of that class)
fixes definitively the respective proportions of its component
parts ; consequently it determines the applications to which
that combustible would be the best adapted. Its quality of
burning with a long licking flame gives it obvious advantages
for evaporating, heating surfaces, &c., over man}' descriptions
of fuel which contain a smaller quantity of volatile matter.
For the generation of steam power, for boiling or concen-

166 On a Veiii of Bi tutu i nous Coal in the Island of Cuba,

trating the juice of the sugar-cane, or for the inanufacture
of gas, this coal is singiilarJy well adapted. As it contains no
sulphuret of iron, the gas manufactured would be free from,
that very deleterious portion or admixture, which is so diffi-
cult to separate from those gases usually manullictured from
bituminous coals containing sulphur. It might also be em-
ployed with advantage in manufacturing lamp-black [Noir de
Jumee) .

Quantity. — As we have no knowledge of coal being ever
before found in formations similar to those in which the mine
of Casualidad occurs, no opportunity is afforded us of reason-
ing from analogy, and from the experience derived from the
exploration and working of similar deposits. It will there-
fore be admitted, that whatever observations we might be in-
duced to hazard concerning the extent of carbonaceous mat-
ter existing here, they would necessarily be founded more or
less upon conjecture.

The outcrop of this singular vein was accidentally disco-
vered where the public road winds down the point of a small
ridge, and was worn down sufficiently deep to expose the
coal and attract attention.

In whatever way we may account for the origin of this re-
markable coal deposit, in a rock of this age, we must be led
to view it, in some measure, in connection with the petroleimi
which is found in the rocks of this region. We observed it
in a liquid form, filling cavities or cells in veins and masses of
chalcedony, a few yards only from the coal vein; and whilst
breaking with the hamnier fragments of euphotide, serpentine,
and various rocks in this vicinity, during a hot day, we per-
ceived a strong odour of pitch or tar, arising after every blow.

The petroleum springs which rise from fissures in the ser-
pentine at Guanabacoa, two leagues distant westward, have
been known for two centuries.

Round a great portion of the Bay of Havana, asphalt is
still collected at low water, under the name oi Chapapote^ and
is employed in the manner of tar, for paying vessels. As this
substance is remarkable for yielding a dense column of black
smoke, when ignited, it has frequently and at various times
been had recourse to for the purpose of making signals along
the neighbouring coast of the island. It is matter of history,
that Havana was originally called by the discoverers and early
occupiers of this part of Cuba by the name of Carine, be-
cause there they careened their ships and pitched them with
the natural tar they found washed on the shores of this beau-
tiful bay.

The position which we have described in the foregoing

Mr. C. Fox on tJie Construction of the Oblique Arch, 167

notice, is not the only one in the island of Cuba where this
remarkable variety of coal exists. Nearly contemporaneously
with the discovery of the coal of Casualidad, it has been ob-
served about midway between the cities of Matansas and
Havana, not far from the sea-coast. If this be not a pro-
longation, at the distance of six leagues, of that we have
here described, it is an additional evidence of the great pre-
valence of bituminous matter in the serpentine and eupho-
tides of Cuba. The vein at this position has not yet been
worked, nor have mining operations been arranged at either
position. Some barrels of the coal from near Matansas have
been lately received at Philadelphia as specimens.

We are not aware that any other of the West India islands
contain coal in sufficient quantity to be worked. In Jamaica,
it appears, on the authority of Mr. De la Beche, coal exists
in veins of an inch or two in thickness, occurring stratified
with the usual coal-measures and carboniferous rocks; but
these veins are too insignificant to be worth mining.

Of the geology of St. Domingo we know very little, and
shall probably remain ignorant for a long time to come.

It were an interesting fact, if it be as we conceive, that this
is the first discovery within the tropics, in this part of the
globe, of workable veins of remarkably pure coal.

Philadelphia, Dec. 20, 1836.

XXXIII. On Mr. Peter Nicholson's Rule for the Construction
of the Oblique Arch, By Charles Fox, Esq.

To the Editors of the Philosophical Magazine and Journal,

Gentlemen,

TT AVING seen in your last Number (p. 75) a letter extracted
^ -* from the Newcastle Journal, addressed by Mr. Henry
Welch to Peter Nicholson, Esq., in which he states " the
propriety of setting the public right as to whom the merit is
due, for a proper and certain rule for the construction of the
oblique arch," and subsequently says, " I think that there can
be no doubt, that your claim to the rule for the proper forma-
tion of the stones is prior to that of Mr. Fox, and I have
yet to learn that any rule exists by which the oblique arch
can be so truly built as the one which you have published ;"
I feel, therefore, bound in justice to myself, briefly to notice
it, and also because the principle laid down in my former
paper (vide vol. viii. of this Magazine, p. Si99) does not ap-

168 Mr. C. Fox on the Construction of the Oblique Arch.

pear to have been clearly understood by the writer of the letter
in question.

The two points to be determined are, whether my rule is
identical with Mr. Nicholson's; and if not, which is the better
of the two.

That they are not identical I hope will be evident from the
following facts ; and which is the better of the two must be
left to the judgement of your readers.

No one would for a moment hesitate to acknowledge the
obligations which practical men are under to that highly ta-
lented individual Mr. Peter Nicholson ; but on referring to
his Treatise on Masonry and Stone-cutting (plate 17), it
will at once appear that the intrado is the only surface de-
veloped, and the approximate line being laid down upon it,
all the courses are drawn at right angles to that line ; the
courses therefore are drawn with reference to the intrado
only. Now my plan is to make use of neither intrado nor ex-
trado for this purpose, but to lay down all the courses upon
a supposed intermediate surface: the two plans are therefore
not identical.

Now the reasons why I conceive my plan to possess ad-
vantages superior to Mr. Nicholson's are these. On referring
to vol. viii. of this Magazine, Plate III. fig. 6, it will be seen
that the angles of the courses, as shown in the developed in-
trado and extrado, differ very considerably, even more than
16^: it will therefore be obvious, that if the angle of the in-
trado is adopted for the rule (as by Mr. Nicholson) then the
angle of the extrado will be wrong ; and again, if the angle
of the extrado were adopted for the rule, then the angle of the
intrado would be incorrect; for in either case the thrust
would not be in the direction of the abutment, which in every
arch is an essential point.

Now to use my own words (vol. viii. p. 302), " It is evident
from fig. 7, that if spiral planes are considered as composed
of spiral lines, placed at various distances from the centre of
the cylinder, each of these lines will form a different angle
with the axis; and therefore, as an arch has always some thick-
ness, that although we have the inner edge of the spiral plane
placed at right angles to the thrust, yet every other portion
is gradually departing from a right angle, and is exerting its
force in an improper direction : thus an arch of this descrip-
tion can never exert its thrust in the direction of the bridge,
but is endeavouring to push the abutments obliquely."

" To get the thrust strictly correct I have supposed the
arch to be cut into two rings of equal thickness (see fig. 8),

M r. G. Fox on the Construction of the Oblique Arch, 169

and having considered the external ring as removed, have
proceeded to develop the outside surface of the remaining
one : this I shall hereafter speak of as the intermediate de-
velopment, as it is the development of a surface midway be-
tween the extrados and soffit or intrados.

" Upon this intermediate development I place the approxi-
mate line, and then draw all the courses square to it, by
which means we obtain a line in the centre of each stone ex-
erting its force in the true direction, as in proportion as the
one half of this bed exerts its force in an oblique direction
on the one hand, the other half acts in the opposite direction,
and is therefore always producing a balance of effect, which
resolves the various forces into one exerting all its power in
the true direction, which is the object to be obtained."

It will be seen that in all the elevation^ of oblique arches
given by Mr. Nicholson, the bed-joints in the face are straight
lines^ whereas by my rule they are necessarily curves (see
fig. 5 of the plate illustrating my paper.)

In corroboration of my statement that "many practical
men have experienced considerable difficulty in the construc-
tion of skew bridges," Mr. Welch has furnished several in-
stances; and the fact which he adduces, that "the executive
engineer of a very extensive public railroad has very prudently
applied to a competent person for a definite development of your
(Mr. Nicholson's) ^nVic/p/^," is really admitting that that prin-
ciple is not developed with sufficient clearness for practical
men in Mr. Nicholson's Treatise. Mr. Welch also seems
aware of some latent defect in Mr. Nicholson's rule, for he
says, " I am firmly of opinion, after an attentive observation
of the practical worJcing of the best'* (meaning of course Mr.
Nicholson's) " rule, that it is very injudicious to adopt them,"
(oblique arches,) "except in cases of absolute necessity;" and
so giving it to be understood that oblique arches built on
Mr. Nicholson's principle are not so substantial as square
ones. Mr. Welch will find it difficult to point out any such
want of stability in arches built on my principle.

Every one will be ready to admit that oblique arches should
be avoided, from being more expensive, and not equal in appear-
ance; but that they are not inferior from any fault in their
*^ practical working,'' my own practical working has established.

I trust that what has been brought forward shows that
Mr. Nicholson's rule and mine are not alike, and therefore
that he has no " prior" " claim" to mine ; and that my rule
possesses advantages not to be found in his.

I am. Gentlemen, your obedient servant,

Park Village East, London, Jan. 19, 1837. CllARLES Fox.

Third Series. Vol.10. No. 60. March \837. Z

[ no ]

XX XIV. Oti the CvystallograpJiical Identity of certain
Minei-als. By H. J. Brooke, Esq., FJi.S., <St.*
[With Figures : Plate I.]
L CffZeagonite, Gismofidin, Abrazite, Aricite, and Phillipsite,

nPHE figures 1 to 4, Plate I., will explain the crystalline
-■• relations of these differently named minerals. Fig. 1.
is the form of Phillipsite, the crystals being composed of
two or four simple crystals arranged in a manner analogous
to those of Harmatome ; I am not, however, aware that any
crystals have yet been found which exhibit this structure as
distinctly as in Harmatome.

The line a b, fig. 1, is in most crystals slightly raised above
the surface, marking the lines of junction of the twin crystals ;
but in some crystals it is scarcely perceptible, and I have
found the inclination of d d', fig. 2, on crystals with bright
faces, differing so little from 90° as to induce my assuming that
as the true angle. On one specimen in my possession there
are both opake and transparent crystals resembling fig. 1,
proving that opacity is not a distinguishing character of this
variety of Zeagonite.

Fig. 2 exhibits the first step in the passage of fig. 1 into
figs. 3 and 4. I have several instances of two crystals, or
bunches of crystals, crossing atright angles and producing the
rudiment of the octahedron, fig. 3, the faces of this octa-
hedron being so marked in all the crystals I have seen as to
indicate its compound structure. I have observed three mi-
nute crystals crossed as in fig. 2, on a specimen in the British
Museum explanatory of the crossed octahedron, fig. 4, for a
very distinct specimen of which I am indebted to the liberality
of Mr. Heuland.

It thus appears that there is no other difference between the
crystals of Phillipsite and the other varieties of Zeagonite than
in the greater or less complexity of crystalline composition.

II. Of Mtirckisonite, Moonstone, and the iridescent Felspar
from Fredricksvarn, Norway,

These have the same cleavages, the same angular measure-
ments; and the play of light is observable in the same di-
reotion on the pa»'ticular cleavage plane, by which Mr. Levy
distinguished the Devonshire Murchisonite from common fel-
spar.

The three varieties may therefore now be classed together
as Murchisonite f.

* Communicated by the Author.

t Mr. Levy's original paper upon Murchisonite will he; found in Phil.
Mag. and Annals, N.S. vol. i. p. 448. —Edit.

Zond.t£dml.I7ul.Maft. irJhum. T^i.JO.Fl.l.

[ ivi ]

XXXV. On the Results of Mr, Fox's Expemnents on the Pro-
dudion of artificial Crystals by Voltaic Action,

"11/^ E have alluded in page 83 of the last Number of this
^^ Journal, in reference to a paper by M. Becquerel in
the Third Part of the " Scientific Memoirs," to the commu-
nications of Mr. Fox and Mr. Crosse at the Bristol meeting
of the British Association relative to the production of artifi-
cial crystals by voltaic action. We are now enabled, by the
kindness of Mr. Fox in sending specimens of the altered
ores for examination, to give a more exact account of the re-
sults of his experiments than we could otherwise have done.

Mr. Fox's own statement is as follows : " The experiment
referred to was performed in the following manner : — An
earthenware trough was divided by a partition of moistened
clay into two cells, into one of which was put a piece of the
yellow sulphuret of copper, the cell being filled with a solution
of the sulphate of copper, and into the other a piece of zinc,
and the cell filled with water, either pure or slightly acidu-
lated by sulphuric acid. The zinc was then connected with
the copper ore by means of a copper wire passing over the
wall of clay. This simple voltaic arrangement soon rendered
the surface of the copper ore highly iridescent, then purple,
and in the course of a few days gray, the gray crust being
covered with metallic copper, deposited in brilliant crystals,
and with a slightly greenish soluble salt. This crust resembled
gray sulphuret of copper, and increased in thickness after the
operation had been continued several weeks."

The crust on the specimens received from Mr. Fox was
thin, and the quantity so small that an exact analysis of it
could not be made. But the result of the examination to which
it was subjected approached so nearly to that of the Cornish
sulphuret as to warrant the conclusion of its being the same
chemical compound. The soluble salt was found to be a sul-
phate of copper and iron, which accounts for the iron that
the yellow copper ore had lost during its conversion into sul-
phuret.

Mr. Fox considers that, assuming the gray crust to be sul-
phuret of copper, as it turns out to be, these results explain
why metallic copper occurs in our mines in contact with gray
and black copper ore, and not with the yellow sulphuret of
that metal ; and likewise why the former is generally found
nearer the surface than the latter, and also near cross courses
and in situations where it is most exposed to the action of

Z2

172 Prof. Schoenbeiii*s Uemarks on Faraday's Hypothesis

water, the expelled ferruginous matter being indicated by.
the ^^ gossan." This usually consists of quartz, as well as iron-
ochre, 8cc., and it abounds in copper veins, but not in those
of tin.

XXXVI. Remarks on Faraday's Hypothesis with regard to
the Causes of the Neutrality of Iron in Nitric Acid. By Pro-
fessor SCHCENBEIN.*

¥N the July Number of the Philosophical Magazine for
■■- 1836, Mr. P^araday has set forth an equally simple and in-
genious hypothesis on the cause of the passive condition as-
sumed by iron in common nitric acid under certain circum-
stances. This distinguished philosopher supposes that the
peculiar action of this metal is caused, first, by a thin layer
of oxide which is formed round the iron wire under these cir-
cumstances ; and, secondly, by the property of this oxide to
be insoluble in nitric acid of a certain degree of concentration.
According to Faraday, therefore, the real cause of the inac-
tivity of the iron would be purely mechanical ; that is, the in-
activity of the iron would originate in the fact, that the metallic
iron and nitric acid do not come into actual contact. In the
same way Faraday seems also to explain the fact which I have
observed, that when a complete circuit of the electric current
is formed, oxygen gas is evolved at the positive iron wire. As
probably his paper on the subject in question will find a place
in this [Poggendorff's] journal, I do not consider it as necessary
to enter into a more detailed account of the hypothesis of which
we are speaking, for the purpose of subsequently referring to
it, and I proceed, therefore, at once to bring forward the facts
which appear to stand in opposition to those of Faraday. I
must first remark, that the surface of an iron wire which has
been made passive by repeated immersions in nitric acid of
1*35 (see my last paperf ) exhibits a much cleaner and brighter
metallic surface than a wire which has been cleaned in any
other manner, and therefore not the slightest trace of a coat-
ing of oxide can be observed by the eye. I will, however,
not lay much stress upon this circumstance, although I think
it deserves some consideration. In one of my former treatises
I have mentioned the fact, that iron wire, in whatever way it
has been made passive towards common nitric acid, acts like
common iron in considerably diluted acid, whilst an iron wire

• From Poggendorff's Annalen der Thysik und Chemie^ vol. xxxix. p. 137-
t Prof. Schoenbein's paper here referred to appears to correspond with

his first paper on the subject in Lond. and Edinb. PhiK Mag. vol. ix. p. 53.

—Edit.

on the Causes of the Neutrality of Iron in Nitric Acid, 173

acting as the positive pole, shows the most absolute chemical
indifference to nitric acid of all strengths. This fact appears
to me to speak strongly against the truth of the English phi-
losopher's hypothesis ; for if we assume for an instant that at
the moment of immersion of the positive iron wire in the di-
luted nitric acid, (in consequence of the decomposition of
water thus caused,) a thin layer of this questionable oxide is
formed upon it, and that in this circumstance the evolution
of the oxj'gen gas originates, we cannot conceive how the
oxide so formed can remain for one instant in dilute acid
without being dissolved in it, viz. in an acid so diluted that,
according to Faraday, the oxide cannot remain any longer
indifferent. In other words, if the chemical indifference of
the iron to the nitric acid were materially influenced by the
degree of dilution of the latter, the iron under the above-
mentioned circumstances would remain active, a nitrate of iron
would be formed, and no evolution of oxygen from the metal
would take place. Experience, however, shows that exactly
the reverse of what one might have expected, according to
the above-mentioned hypothesis, takes place. Faraday, to be
sure, mentions that iron in nitric acid (the strength oi which,
however, is not given,) is dissolved even when it acts as the
positive pole in it. According to my experiments, of which
I may assert that they were conducted with the greatest pos-
sible care and accuracy, no trace of this metal is dissolved
under the circumstances stated in nitric acid which is several
times diluted with water. 1 kept an iron wire, which was
united to the positive pole of a cmironne des tasses of 15 jars,
for many hours in such an acid without being afterwards able
to distinguish the smallest trace of iron in it. If however
to such an experiment acid of common strength, as, for in-
stance, of 1*35, is added, the result is somewhat different; in
this case it contains, after some time, always a little oxide of
iron. According to my conviction this is not formed in the
acid, but a nitrate of iron is produced on that part of the wire
which reaches above the acid, by the acid vapours continually
rising, which nitrate is then conducted down into the acid
by capillary action. A more important fact, to which I must
draw attention, is the circumstance that the iron wire which
dips into the diluted acid and is indifferent to it, is acted upon as
soon as the electric current ceases to pass through it. U, for
example, we allow the iron wire to remain in the acid to be
examined, and interrupt the current anywhere, the wire im-
mediately appears surrounded by heavy yellowish brown
striae, which are a nitrate of iron. From these facts it ap-

1 7* Oh the Causes of ike Neutrality of Iron in Nitric Acid.

pears, that ihe most important cause of the chemical indiffer-
ence of tlie iron to the nitric acid is neither owing to its being
surrounded by a thin pellicle of oxide, nor to a certain quan-
tity of water in the acid, but directly to the electrical current
in "whatever manner it acts. Moreover, it is clear, that if the
indifference of the positive iron wire depended upon a thin
coat of oxide which surrounds it, the same wire ought to re-
main passive when it is separated from the pole, and put into
common nitric acid, which however is not the case. The
fact that the positive iron wire is acted upon similarly in other
dilute acids as in nitric acid is rather unfavourable to Faraday's
hypothesis. It is well known that iron becomes quite passive
by being merely once dipped into fuming nitric acid : how
then is the pellicle formed in this case? I suppose only by
the decomposition of the nitric acid, because nothing else is
possible. I doubt however very strongly whether this takes
place ; but if it does not take place, it is very difficult to ascer-
tain in what manner the iron does become oxidized. I must,
however, remark that the galvanometer during the dipping of
the iron in highly concentrated nitric acid indicates a weak
electric current, but it appears to me that this does not prove
the oxidation of the metal. To the above remarks I must
add one more, which 1 think is not unimportant as regards
this subject. In my last paper 1 spoke of an action of an
acid of 1 35 upon the iron which took place by starts, and
I showed that it was occasioned by the metal becoming
active and passive. Faraday would explain this appearance
by the supposition that at one instant a pellicle of oxide is
formed round the wire which protects it from the action of
the nitric acid, but that in the next the pellicle is dissolved
in the acid, and would expose by that means the clean me-
tallic surface of the wire to the acid fluid. But this man-
ner of explaining it contains a contradiction in itself; because
it first makes out the pellicle to be insoluble in nitric acid,
and then to be soluble ; it cannot therefore be correct. More-
over, one might put the unanswerable question, why iron by
frequent immersions in common nitric acid is rendered j)as-
sive; therefore, why an oxide is formed which in the first
place enters into combination with the acid, but afterwards
remains in the same acid an insoluble oxide? All the reasons
above given decide me to suppose that Faraday's views con-
cerning the passive state of the iron do not explain it satis-
factorily.

Bale, October 2, 1836.

[ 175 ]

Note from Professor Faraday to Mr, Richard Taylor on the
preceding Paper.

Dear Sir,

¥ AM mucli obliged to you for a sight of M. Schoenbein's
* paper, the experiments and observations in which are ex-
cellent. The cause of the phaenomena he has so well distin-
guished is indeed exceedingly difficult to be distinguished
at present, and I was in hopes that the doubt on my mind
when I ventured the view referred to would be evident from
my words, " My strong impression is," &c.* Moreover,
M. Schoenbein, and also M. Alb. Mousson in an attempt
which he has made to explain the cause t, have not given
my view clearly. I have said, that my impression is, that
the surface of the metal is oxidized, or else that the supe?-^
Jicial particles of the metal are in such relation to the oxygen
of the electrolyte as to be equivalent to an oxidation J; mean-
ing by that, not an actual oxidation, but a relation Hke that of
the particles of amalgamated zinc to the oxygen of the water
in dilute sulphuric acid before the electric current which
tends to be formed is established. (See Experimental Re-
searches, Eighth Series, par. 949.)

The state seems to me to be one of a very delicate equili-
brium of forces, though of course that condition of things
which can produce it can also retain it; and this notion seems
to be confirmed by the intermitting action originally mentioned
by Herschel. I quite agree with M. Schoenbein's conclusion,
" that Faraday's views concerning the passive state of the
iron do not explain it satisfactorily," and I only regret that
the other views which have been put forth are, as far as I
can perceive, not more satisfactory. For instance, that by
M. Mousson leaves out of view the capital and leading fad, that
apiece of iron in the peculiar state may remain for six months
(as I know by experiment) in nitric acid of sp. gr. 1*35 with-
out being in the least affected, although no platina or primary
metal is in contact wiih it.

I was somewhat struck the other day, whilst readii.g in your
useful ' Scientific Memoirs' M. Nobili's paper on a new chro-
matic scale, on finding that he accounts for the colours of his
thin plates by assuming films of oxygen and acid || ; which he
considers asadhering permanently to thesurfaces of the platina,
iron, and steel plates which he used in his experiments, without

* Lond. and Edinb. Phil. Mag., vol ix. July 1836, p. 61.
t Lihliotheqite Universetlc dc Geneve^ Sept. 1 836, p. 1 65.
X Lond. and Edinb. Phil. Mag., vol. ix. July 1836, p. 61.
jl Scient. Mem , Part 1. p. 108

1 76 Report on the New Dioptric Light of the Isle of Mai/,

however being in combination, chemically, with the metal.
This is going much further in the idea of association without
combination than I have done. 1 merely mention the fact for
the purpose of directing M. Schoenbein's attention to the con-
dition of the iron and steel plates in Nol)iii's experiments.
My own impression at present is, that Nobili's thin plates
consisted of peroxide of lead formed at the positive electrode
in the solution of acetate of lead used ; and that it is just pos-
sible some of the differences between his tints and those of
Newton may depend upon, and some of his conclusions be
affected by, the circumstance that peroxide of lead has a power-
ful specific action on light, and is even in moderately thin
plates deeply coloured.

I trust that M. Schoenbein's perseverance will very shortly
produce that reward it so well merits, the true explication of
the cause of the peculiar state of iron.

I am, my dear Sir, very truly yonrs,

Royal Institution, Jan. 21, 1837. M. Faraday.

T

XXXVII. Report hy a Committee of the Royal Society (of
Edinburgh) regarding the New Dioptric Light of the Isle
of May,*
HE Committee of the Royal Society appointed to co-
operate with the Commissioners for Northern Lights, met
at Dunbar, on Wednesday, 2Gth October 1836. Present,
Right Hon. Lord Greenock, V.P.R.S.E.; Mr. Robison,
Sec. R.S.E.; Dr. Traill, Dr. Christison, Professor Forbes.
Present also, Mr. Alan Stevenson, on the part of the Com-
missioners.

The Committee were requested to compare the new fixed
dioptric light on the Isle of May, thirteen miles distant, with
the old catoptric light, placed on a temporary erection near
it. From the first point of observation, near the town of
Dunbar, the Committee were unanimous in pronouncing the
great superiority of effect of the new light, which appeared
brighter than the old one in the ratio of not less thaii 4 or 5
to 1. But upon changing the position of the point of obser-
vation to the eastward, the difference became less marked, and
at a distance (from the first station) of about one and a half
miles was scarcely appreciable, though the new light appeared
whiter and somewhat better defined. The reason of this
prodigious inequality of the old light in different azimuths,

* Communicated to the Committee of Northern Lights, 28th Octoher
1826, and to the Lond. and Edinb. Phil. Mag., by Prof. Forbes.

lleport on the New Dioptric Light of the Isle of May, 177

Mr. Alan Stevenson, the assistant-engineer, explained to be,
that since the divergence of the reflected beam is produced
by placing the lamp a little out of the focus of the mirror, the
central pencil of reflected light is much less scattered than the
lateral pencils, which in an azimuth [azimuths] exactly inter-
mediate between the axes of two adjacent reflectors is [are]
very feeble indeed. The evening of the 26th was neither re-
markably clear, nor remarkably the reverse, and the members
of the Committee were satisfied that a slight increase of haze
would have rendered the old light wholly invisible at the
town of Dunbar, which appears to be placed (in the present
temporary position of the reflecting system) in the line of least
illumination.

The number of mirrors in the old system being twenty-
four*, and the divergence given to the reflected light 15°, a
certain portion of light is thrown all round the horizon, but
the intensity in different directions varies (as has been said)
prodigiously. The divergence of 15° in a vertical plane also
taking place as a necessary consequence of this method of ex-
panding the reflected beam, by unfocusing the lamp, pro-
duces a useless and most injurious expenditure of light in di-
rections in which it can never be seen. On the other hand,
the dioptric system of hoops, besides the great advantage ob-
tained by substituting refraction for reflection (from the less
loss of light) rigorously fulfils the requisite geometrical con-
dition of spreading a plane of light, exhausting the whole
available light of the lamp, of precisely equal intensity in all
directions. This has never been attempted by any combina-
tion of reflectors.

The distance of the Isle of May from Dunbar being thirteen
miles, the range of one mirror on the old system extending
through about 15°, would not differ much from a linear di-
stance of three miles in a direction perpendicular to a line
joining Dunbar and the May. The space between maximum
and minimum light would therefore be about a mile and a
half. The space walked over must have nearly included a
complete series of the variations of the light. Assuming the
average light of the mirrors at half that of the dioptric light
(which certainly does not seem too much), we have a supe-
riority of two to one in favour of the latter at a distance oi
thirteen miles. These are to be considered, however, but as
rude ocular estimations.

• It appears that at the Isle of May there are only twenty-two reflectors
of a larger size, the divergence being proportionally increased in order to
complete the circumference. (Initialed) J. D. F.

Third Sef'ies. Vol. 10. No. 60. March 1837. 2 A

178 Mr. Thompson on the Soluhilitfj of

But it is not to be inferred that the ratio of the intensities
of the two systems will remain the same at all distances.
Were the refracted light in one plane (instead of having a
vertical divergence of 6°), and were the reflected light com-
prised within a cone uniformly illuminated (which is not the
case), the light from the first would vary inversely as the di-
stance, from the second inversely as the square of the sum of
the distance and a constant which depends upon the diver-
gence; but neither of these conditions being fulfilled, the re-
spective illuminations must vary with the distance according
to two other distinct laws, each much more complicated. It
is clear, therefore, that the comparison made at one given di-
stance will not apply to any other given distance. But still
the effect of distance in modifying intensity, may be much
more accurately estimated in the case of the prismatic than of
the reflecting arrangement.

The following conclusions seem to be warranted :

1. That, at a distance of thirteen miles, the mean effect of
the new light is very much superior to the mean effect of the
old light (perhaps in the ratio of two to one).

2. That at all distances the new light has a prodigious su-
periority to the old, from the equality of its effects in all azi-
muths.

3. That the new light fulfils rigorously the conditions re-
quired for the distribution of light to the greatest advantage.

4. That at distances much exceeding thirteen miles, the
new light must still be a very effective one, though to what
extent the Committee have not observed. The light is under-
stood to be still a good one, when seen from Edinburgh at a
distance of about thirty miles.

XXXVIII. Remarks on Mr. Brett's Experiments on the Solu-
bility of Metallic Oxides and Salts in Muriate and 'Nitrate
of Ammonia. By L. Thompson, Fjsq^.^ Member of the lloyal
College of Surgeons,

To the Editors of the Philosophical Magazine and Journah

Gentlemen,
T OBSERVE a serious omission in the laborious experi-
-■• ments of your correspondent, Mr. Brett, on the solubility
of metallic oxides and salts in muriate and nitrate of am-
monia, inserted in your last Number, p. 95, which, if uncor-
rected, is likely to produce an erroneous opinion as to the

Metallic Ojoides and Salts in Muriate of Ammonia, 179

cause by which such solution is effected. From the general
tenor of the paper it is evident that Mr. Brett supposes, that
when a metallic oxide or salt is dissolved in a solution of mu-
riate or nitrate of ammonia, no decomposition takes place, and
that the metallic oxide or salt is merely, as he expresses it, "dis-
solved by the muriate or nitrate of ammonia." This, however,
is by no means a correct view of the case ; for on repeating a
few of the experiments proposed by Mr. Brett, I find that
when a solution of muriate of ammonia is boiled with any of
the under-mentioned metallic oxides or salts, viz.

Protoxide of mercury, peroxide of mercury, red oxide of

mercury by nitric acid, protoxide of lead, protocarbo-

nate of lead, oxide of zinc, carbonate of zinc, peroxide

of copper, and subnitrate of bismuth,

a very free evolution of ammonia takes place, and a metallic

chloride is formed, which combines, in some instances, with

part of the muriate of ammonia, forming a triple salt. The

theory of this process is too simple to require an explanation.

I have not performed any other of Mr. Brett's experiments,
but deem the hvf I have thus briefly detailed, sufficient data
from which to infer that decomposition occurs in almost every
instance ; for although it may be difficult to prove that phos^
phate of ammonia and muriate of lime are formed when phos-
phate of lime is dissolved in muriate of ammonia, yet analogy
favours such an opinion. The inefficacy of nitrate of am-
monia when contrasted with the muriate may be ascribed to
the trifling affinity existing between nitric acid and the metallic
oxides when compared with the attraction of their metals for
chlorine.

I have no doubt that on a repetition of his experiments
Mr. Brett will find ample reasons for changing his present
idea, for when large quantities, as two drachms, are operated
on at once, no better test than the nose is requisite for deter-
mining the presence of the ammonia evolved.

I am. Gentlemen, yours, &c.

Roebuck Place, Great Dover Road, Lewis Thompson,

Feb. 6, 1837. M.R.C.S.

Errata in Vol, ix. — In the heading of my paper, p. 442,
for " lodous Acid^^ read " Iodic Acid ;" and in the same page,
line 19, for "2^ atoms or 295 grains of recentlif precipitated
oxide of silver" read " 5 atoms or 590 grains", &c.

Dec. 20, 1836.

2 A 2

[ 180 ]

XXXIX. On tJie Solar Eclipse of May 1 5th, 1836.
Bj/ C. RUMKER, Esq,

2\) the Editors of the Philosophical Magazine aiid Journal,
Gentlemen,
TN the calculation of this eclipse, the following method has
^ been adopted : Suppose <^ to denote the geocentric latitude,
T the apparent time from noon, t the north polar distance of
the sun, tt the difference of horizontal parallaxes reduced for
the spheroidical figure of the earth, X parallax in longitude, /3
moon's apparent latitude — sun's latitude.

3600''

H =

([ 's relat. hor. mot. in M

P f Noon in Green. 15 May 75° 53' 40''-6 R sun*s \ semidia-

^ tor mean | Mj^j^jg^t 15 May 76 3 21 -0 ^ moon's J meter.

S = K—r + g, D = R — r — §, where r is to betaken out of the
following table to be entered with h cotan <p cos t = tan m . ,

cos <p sin T = sm n ,

sin (5— 7»)
tan 71

= cotan r,

sin n
sin r

= cos h

TT COS h cos (|u, + v) = A, TT cos h sin (ju^ + v) = parallax in lat.

(v^(S^-f3^) + x)H = dr.

The upper sign of v is to be used in the forenoon, the lower
in the afternoon. When the sun is in the descending signs
180°— jx is to be used in lieu of jtt.

Table of Diminution of the i

)W

i^s Semidiameter,

hO

9

§7

§|"9

o 1 o ' o
1011 12

1 .

o I o 1 o
13|14,15

C-5 ^O CO

I%.°7

o 1 o i o
181920

o
21

o 1 o o o

22232425

0 1 0 1 0 1 0 1 0 0
26|27 28^29 30^31

0
32

0
33

r"

i

lO 00 o ,o

S'S'2

gfi

§i"'s

CO

<0 00

10

i

00

g

oco'o

CJ 10 00

9 9* !■?*

S
t-

00

—
00

2*

•"•

-r'^'r

C< |C< CO

CO CO CO

t

■it "^jib

to

■"h

<o

"

0

«

t^ r^ t--

r^

i>

00

h° 134

35|36

o I o I o I o I o

373839,40,41

o o o ! o o
42 43,44 45'46

0000
47|48 49,50

0000
5l|52 53 54

o ' o o I o I o

55,56 57i58 59

o o I o
606162

— CO
00 icr>

do ,6d

O '<N

6 !6

C< 00 Ut F^ '00

CO to lr^jO^|-^
6 |6 6 6 '^

rM CO

00 'CO

Tf,<M t-'t-. ro

uo :o "^ 00 (N
CI ht kp (p op

o ''^ a>
lo'oo o
9^,9 i'?'
6j coico

I measured at Hamburgh at the time of the greatest obscu-
ration, the distance between the sun's and moon's south limbs,
y 5T'*25, whence the apparent distance of centres is found
63"-9, and the apparent difference of latitude 64''-0, instead
of which the Nautical Almanac gives 70''*6. Hence it follows
that a correction of — 6''*6 must be applied to the latitude

Mr. Rumker on the Solar Eclipse of May 15, 1836. 181

given in the Nautical Almanac, which is further corroborated
by the observations made at Copenhagen, Koenigsberg, &c.

In comparing the observations made at places situated on
the borders of the Annulus, with the computation according
to the elements of the Nautical Almanac, I find a better ac-
cord by assuming for latitude correction — 7'''63, and for
correction of the sun's semidiameter -^\"*5y and for correction
of the moon's semidiameter +0''*5.

These corrections have been previously applied in the fol-
lowing calculations. B means beginning ; BA, beginning of
annulus; EA, end of annulus; E, end,-d. (0+ ([ ), difference
of sum or difference of semidiameters ; d /3, of latitude ; d tt,
of parallax.

Places and
Observers.

Mean Time of
Observation.

c»jiL^:L. <• (oi o d/. d.

Altona.
Schumacher.

h m s
B 2 43 50-75
E 5 21 •23-15

2 46 51-02 +21776+0-1137+11131
2 46 52-3 -2-1810+0-1523+1-5385

Apenrade.
Haussen.

B 2 40 368
BA 4 0 4-8
EA 4 4 23-8

2 45 14-37 +2-1842-I-0-2045+ 1-0263
2 44 52-2 +2-2260-1- 0-4730-1- 1-1672
2 44 52-8 -2-1834-0-1912+1-5387

Berlin.
Encke.

B 3 2 43-8
E 5 37 31-9

3 0 41-3 +2-1751 + 0142741-2394
3 0 45-1 -2-1820+0-1670 + 1-5782

Bern.
Treschel.

B 2 37 8-6
E 5 16 48-26

2 37 17-63 +2-1962-0-2997+ 1-3277
2 36 43-36 -2-2468+0-5608+1-5060

Bremen.
Cluver.

B 2 38 7-0
E 5 16 56-9

2 42 13-38 +2-1760+0-0787+1-1087
2 42 14-8 -2-1850+0-1998+0-8576

Bremerhaven.
Thulesius.

B 2 37 27-0
E 5 15 270

2 41 58-7 +2-1783+0-1264+1-0751
2 41 24-17 -21821 +0-1678+1-5286

Brussels.
Quetelet.

B 2 16 0-5
E 4 59 47-3

2 24 35-66 +2-1750-0-0300+1-0779
2 24 33-9 -2-2058+0-3635+ 1-4712

Copenhagen.
Petersen.

B 2 55 52-8
BA 4 15 53-2
E 5 29 32-9

2 57 28-93 +2-1876+0-2378+1-0605

2 57 13-8 +1-4532

2 57 110 -2-1757+00121+1-5802

Gera.
Engelhard
and Metz.

E 5 33 43

2 55 23-9 -2-1926+0-2724+ 1-5600

Greenwich.
Airy.

Halifax.
VVaterhouse.

E 4 39 12-32

2 7 4-62 -2-2067+0-3693+1-4070

E 4 27 70

1 58 43-9 -2-1914+0-2624+1-384

Hamburg.
Peters.

B 2 44 7-4

E 5 21 30-5

2 47 5-7 +2-1776+0-1135+1-1101
2 46 59-5 -2-1810+0-1526+1-5442

Hamburg,
llumker.

B 2 44 2-2
E 5 21 40-5

2 47 0-54 +2-1776+0-1135+1-1101
2 47 8-89 -2-1810+0-1526+1-5390

182 Mr. Runiker on the Solar Eclipse of May 15, 1836.

Places and
Observers.

Mean Time of
Observation.

Ecliptic
Conjunction.

d(0±([) d/3 d*

Hanover.
Lahmcyer.

h m s
2 43 4904
5 21 48-73

2 46 6-69 +2-2 139 4- 0-4 152 -I- 0-98 11
2 45 56-43 +2-1866+0-2182-I- 1-5304

Jona.
Schrcen.

5 31 35-0

2 53 28-45 -2-1942+0-2845+1-5501

London,

Fleet -street
W. Siinms.

B 1 51 13-0
E 4 38 47-0

2 6 59-43 +2-1750+0-0450+0-9154
2 6 47-2 -2-2066+0-3685+1-4115

Louvain.
Crahay.

Makerston.

Sir'lTiomas

Brisbane.

B
E

2 17 37-3
5 0 52-6

B

B^
EA
E

1 36 51-2
3 1 4-2

3 5 11-6

4 23 0-6

2 25 47-55
2 25 33-6

+2-1748-0-0289+0-8620
- 2-2049+0-3580+ 1 -4748

157 17-2 4 2-1967+0-3111+0-6287

1 57 191 +2-2710+0-6532+0-8621

1 57 5-5 -2-1870-0-2284+1-7380

1 57 4-0 -2-1 809+0-1515+ 1-3888

Neumiihfen.
Zahrtmann.

2 43 54-4
5 21 20-6

2 46 54-4
2 46 49-9

+2-1775+0-1128+]
-2-1810+0-1530+]

-1103
•5475

Neu Strelitz.

Lorenz and

Becker.

3 0 28-0
3 54 58-

Rostock.
Karsten.

Shooter'sHill.
Simms and
Gilby.

B 2 54 43-1

BA 4 14 197

EA 4 17 58-2

E 5 29 58-2

1 51 52-1
4 39 20-1

2 59 31-5
2 59 17-7

+2-1764+0-0879+ 1-1987
-2-1799+0-1367+1-5722

2 55 318 +2-1788+0-1349+1-1418

2 55 39-6 +2-4635- 11568+21523

2 55 35-3 -2-6073+ 1-4378+0-7263

2 55 28-0 -2-1401+0-0997+1-5704

7 26-46
7 26-7

+2-1750+00402+0-9229
-2-2080 -1-0-3768+1-4150

Stettin.
Dancke.

Stralsund.
Steinort.

Strassburg.
Herrens-
scheider.

Tondern.
Petersen.

Wurzburg.
Schroen.

B

E

3 7 51-7
5 41 16-3

B

BA
EA
E

2 59 44-2
4 18 7-0

4 22 26-6

5 33 49-2

5 21-0
5 21-9

+2-1782+0-1256 + 1-2064
-2-1782+0-1061 + 1-5925

3 0 3-34 +2-1803-0-1576+ 1-3025

2 59 24-9 +21891 -0-2469+1-6207

2 59 28-2 -2-2254+0-4705+ 1-2856

2 59 25-8 -2-1785+0-1111+1-5605

B 2 36 25-14 2 38 1-37 +2-1830-0-1911 + 1-2692
E 5 16 4495 2 37 486 -2-2232+0-4575+1-5100

B 2 37 151

BA 3 57 26-88

EA 4 1 48-1

E 5 14 51-12

B 2 47 4-0

2 42 34-9 +21839+0-2009+1-0156

2 42 34-68 +2-1793+0-1357+1-2584

2 42 342 -2-1797+0-1421 + 1-3404

24231-3 -2-1775+0-0903+1-4744

2 46 54-4 +2-1773-0-1071 + 1-2704

Vienna.
Litlrow and
Ilallasckka.

E 5 34 37-1

3 12 31-85 -2-2050+0-35904 1-5910

Zeitz.

E 5 32 40

2 54 37-6 -2-1911+0-2602+1-5598

Ofi Ncwloii's llings and the Fixed Lines of the Spectrum. 183

N.B. Should it be in your power to procure me any ob-
servations made of this eclipse in England or America, you
would greatly oblige thereby

Your obedient Servant,

Hamburg, Oct. 5, 1836. C. RuMKER.

XL. A simple Mode of exhibiting Newtoji^s Bings, and a
Mode of exhibiting the Fixed Lines in the Spectrum, By
the Rev. W. Ritchie, LL,D.,RR.S., Professor of Natural
Philosophy in University College^ and in the Royal Institu-
tion of Great Britain,*

1. T^O exhibit Newton's rings a lens of a long focal di-
-*- stance is generally considered necessary, which is both
expensive and difficult to obtain. In a lecture which I de-
livered nearly two years ago in the Royal Institution, 1 showed
a very simple mode of performing the experiment, which, I
have no doubt, will be acceptable to many of your readers.
Take two circular pieces of thin plate glass (Dutch plate)
about six or eight inches diameter.

Gild a ring of one of the plates about a quarter of an inch
broad from the circumference of the circle with gold-leaf,
place the plates over each other, and by means of a rectan-
gular frame of iron or brass and a screw, bring the plates to
touch in the centre. Let a b
represent the glass plates, B C
the rectangular frame, S a
screw, and A a projecting point, b

By means of the screw the
plates will be brought to touch
in the middle, whilst they are
separated at the circumference

by a single gold-leaf. When this is held so that light from
the sky or a lamp falls obliquely on the plates so as to be re-
flected by the under plate to the eye, the rings will present
themselves in circles round the dark spot in the centre.

2. Procure a prism of good flint glass, having one of its
angles containing 70 or 80 degrees. Place two thin slips of
metal with smooth edges in an opening in a window-shutter,
through which the white light of the clouds is admitted. View
i\{\sfilm of light through the large angle of the prism kept
close to the eye, and the principal fixed lines as well as many
of the others will be distinctly visible. If a bottle containing
nitrous gas be placed opposite the opening, the lines will be-
come more strongly marked and more numerous. With one

* Communicated by the Author.

s

184« The Rev. J. B. Reade on 'producing Achromatic Light

of my finest prisms this spectrum appears like a piece of
striped cloth.

I

XLI. Oil a Method of producing Achromatic Light in Solar
and Oxy-hydrogen Microscopes, and on the Effect of a Cur-
rent of Air upon the Rays that occasion Heat, By the Rev,
J. B. Reade, ill. y^.*

T will no doubt be admitted, that the experiments of Mel-
loni on radiant heat and light have not only given us much
insight into the nature of these two agents, but have also
tended to solve the important problem which had been raised
as to their identity. Henceforward, therefore, any new facts
can occupy but a secondary place, and, however interesting
in themselves, their real value must depend on their conform-
ing to a theory which has already been independently proved.

The received theory is, that the luminous and calorific rays
are two essentially distinct modifications which the aethereal
fluid suffers in its mode of existence, and that they may be
easily separated the one from the other by transmitting the
sethereal fluid through screens of different substances.

Melloni, in his experiments, has employed a variety of ra-
diating sources, and received the rays on screens of coloured
and uncoloured glass, liquids, and crystallized bodies. The
tables with which he has furnished us of both solid and liquid
bodies, exhibit the common thickness of the screens employed,
and besides the substance, the indications of the thermomulti-
plier, and the number of rays transmitted as compared with
the whole radiation. The effect produced appears to vary
with nearly every variation of the substance, and it is only
with sulphate of copper, and a peculiar species of green glass
coloured by means of oxide of copper, that no calorific action
is perceptible.

In following out Melloni's idea of the separation of the ca-
lorific and colorific raysf, I have sought in my own experi-
ments to attain this object by modes sufficiently effective in
themselves, and, at the same time, admitting of such easy ap-
plication to the solar and oxy-hydrogen microscopes, that
achromatic object-glasses, and objects mounted in balsam, may
be used without risk or danger.

That method which I have found to be very successful, and
attended with the least possible amount of trouble, consists, as
I have stated in a paper communicated to the Royal Society,
in a certain position of the condensing lens and the field-glass
of the solar microscope, by which a difference of at least 50°

* Communicated by the Author.

[f A translation of Melloni' s paper on this subject will be found in
Scientific Memoirs, Part III. p. 388.— EniT.]

in Solar and Oxyhydrogen Microscopes. 185

of temperature is indicated by the thermometer at the foci of
these two lenses. It appears, however, upon trial, that the
crossing of the rays between the lenses so materially affects
the illuminating power, ^hen a terrestrial source of light is
used, that the applicability of this arrangement to the oxy-
hydrogen microscope becomes extremely questionable. I have
therefore proposed two new methods, which appear both to
improve the light and to remove all injurious heat.

The light is improved by a combination of different lenses.
After the rays proceeding from a column of lime have been
rendered parallel, they are received on what may be properly
termed the condensing lens of the instrument. A very deep
double concave lens is then placed within the focus now ob-
tained, so that the condensed emergent pencil is of small dia-
meter, parallel, and nearly achromatic. We then proceed as
usual with the field-glass and the object-glass. With this
arrangement only have I been able to see, with entire satis-
faction, the longitudinal and cross lines on those scales of
butterflies' wings which are received as test objects-, and this
distinctness evidently arises from effecting, by means of the
concave lens, an almost entire removal of the blue rays,
which in any other adjustment of lenses occupy the middle
of the illuminated disc.

The heat is also partially removed by this combination of
lenses ; for, as calorific rays, like luminous rays, are suscep-
tible of refraction, it will follow from the different positions of
the principal foci of light and heat in the axis of the conden-
sing lens, that when the concave lens renders the colorific rays
parallel, the calorific rays will, in this case, diverge. But to
procure a practically efficient removal of the heat, I have pro-
posed to transmit the rays through a current of air. That
such a method should not have occurred to Melloni cannot
but be a matter of surprise, though perhaps, indeed, it may
seem somewhat unphilosophical to blow with a pair of com-
mon bellows upon the rays of the sun, under the expectation
of putting out the heat. But, be this as it may, the effect is most
decisive ; for, as it will presently appear, this useful household
instrument, like the traveller in the fable, blo'ws both hot a7id
cold.

After the idea of using the bellows had suggested itself to
my mind, I took the first opportunity which occurred of
placing a delicate thermometer in the focus of the condensing
lens of my solar microscope. By directing a current of air
upon it, the calorific energy of the solar beam was suddenly
diminished, and, after a few blasts, the thermometer indicated
about 60° of temperature only. It is quite evident that no-

Third Series. Vol. 10. No. 60. March 1837. 2 B

186 The Rev. J. B. Reade on the Oxyhydrogen Microscope,

thing would be easier than to direct a continued current upon
a thin screen of ghiss placed just behind the object in the mi-
croscope, by which means the uniform and low temperature
thus steadily maintained would ensure perfect safety even for
the most delicate animalcules.

Under the impression that some change would be indicated
by the thermometer if a current of air were impinged upon
it when it indicated the ordinary atmospheric temperature, I
directed against the bulb about thirty blasts with the bellows.
I confess I was not prepared to find, after just witnessing the
rapid fall of the mercury, that a decidedly opposite effect woukl
be produced. The mercury, however, now rose in different
thermometers, placed both in the house and also in the open
air, between five and seven degrees. In each experiment the
bellows, before they were used, had acquired the temperature
of the surrounding air, and the first four or five blasts pro-
duced at least one third of the whole elevation. We have,
therefore, before us these two facts, that a current of common
air is a powerful absorbent of the rays that occasion heat ; and
that in the blast of bellows by which this current is main-
tained there are equal and opposite forces tending to produce
equilibrium. These two forces consist in a refrigerating and
a calorific current, which have each a separate existence. The
former is effective if the mercury be artificially raised, and the
latter if it indicate the temperature of the air. In the first
case the calorific principle in the solar ray is imparted to the
current of air and absorbed ; and in the second, the calorific
principle in the current of air is imparted to the thermometer
and retained. And hence it must be admitted, however it may
appear to contradict our sensations, that the blast of a pair of
bellows is at least 5° warmer than the air they receive. To ac-
count for this fact it is only necessary to refer to the general
law established by Clapeyron, whose memoir on the motive
power of heat has found a place in Part I. of Mr. Taylor's new
and very valuable quarterly publication entitled " Scientific
Memoirs." The law at which Clapeyron has arrived, and
which is applicable to all the substances of nature, solid, li-
quid *, or gaseous, is, that if the pressure supported by differ-
ent bodies, taken at the same temperature, be augmented by
a small quantity, quantities of heat will be disengaged from
them, which will be proportional to their dilatability by heat.
But it is beside my purpose to enter further into this subject.
I have already accomplished the object I had in view by show-
ing that the free passage of a current of air absorbs the calo-

* The impact of a current of water on a thcnnometer produces an ef-
fect similar to the impact of a current of air.

On the Reflex Fund ion of the Spinal Marrow. 187

rific ra^'s, and thattlic introduction of a concave lens tends to
achromatize and improve the light. Our solar and oxy-hy-
drogen microscopes, therefore, instead of being used for pur-
poses of amusement only, and limited to the exhibition of ob-
jects which are not affected easily by heat, may henceforward
be employed for purposes of scientific ijivestigation, and there-
by assume the more important rank of valuable philosophical
instruments.

Peckham, Feb. 10,1837.

XLII. On Professor Muller's Account of the Reflex Func-
tion of the Spinal Marrow. Communicated by Marshall
Hall, M.D., F.R.S., 8fc. (

[Continued from p. 129, and concluded.]

"T^R. MARSHALL HALL distinguishes four kinds of
^-^ muscular contraction: 1st, The voluntary, which appears
todepend on the brain; 2nd, The respiratory*, which appears to
depend on the medulla oblongata; 3rd, The involuntary, which
depends on the nerves and muscles, and requires the immediate
application of stimuli to the muscles provided with nerves, or
lo their nerves ; and 4th, The reflecting, which continues, in
part, after the voluntary and respiratory have ceased, and is
connected with the medulla spinalis. It ceases after removal of
the spinal marrow, though irritability does not diminish. In
this fourth the motor stimulus does not originate in a central part
of the nervous system, but at some distance from the centre ;
it is neither voluntary nor direct in its course, but rather ex-
cited by peculiar stimuli, which act, not immediately on the
muscular fibres and motor nerves, but on membranous ex-
pansions, from which the stimulus is conducted to the medulla
spinalis. Dr. Marshall Hall illustrates the importance of this
reflecting function of the medulla oblongata and spinal marrow
by some instances. The prehension of food is a voluntary act,
and cannot be performed after removal of the brain ; the pas-
sage of the morsels of food over the glottis and through the
pharynx depends on the reflex function, and still continues
after the brain is removed. Although, for instance, the
muscles whicli are active in this case, may also act voluntarily,
yet the presence of the morsel in the pharynx produces a se-
ries of violent motions, which have been described above
(p. 479.), and which arise from the stimulus of the morsel

• I am now of opinion that respiration itself is a part of the reflex or ex-
cito-motory function, and dependent upon appropriate excitor nerves. —
M. H.

2B2

188 Prof. MuJIer and Dv. Marshall Half

acting on the sensitive mucous membrane, and this per-
ception exciting the medulla oblongata to discharge in the
motor nerves. Dr. Marshall Hall regards the further act
of deglutition in the oesophagus as the effect of the stimulus
acting immediately on the muscular fibres of the oesophagus,
and the result of the irritability of the latter, which may ap-
pear very doubtful*. Even in beheaded young animals -we
may, however, as already shown, observe the reflected mo-
torial excitement still following mechanical stimulation of the
pharynx. Dr. Marshall Hall next shows the permanent in-
fluence of this function in the sphincters. The sphincter ani
remains closed in a tortoise after decapitation, so long as the
lower part of the spinal marrow is uninjured, but instantly
becomes flaccid and opens, when the spinal marrow is re-
moved.

" Dr. Marshall Hall divided the spinal marrow in a live Co-
hiber natrix between the 2nd and 3rd vertebrae. The motions
ceased at once, and when the animal was not stimulated it re-
mained quiet. But if it were stimulated, it continued moving for
a long time ; for at every altering position new parts ot" its
surface came in contact with the ground : gradually it again
became quiet, but the slightest touch again renewed the mo-
tion.

>" Dr. Marshall Hall shows very beautifully the relation of
the voluntary, respiratory, and reflected motions, when he en-
deavours to prove, that the reflected motions which take place
after loss of the brain are not dependent on true sensation^
but only on the centripetal nervous actions which take place
in sensations. Sensation, will, motion, are the three links
of the chain, when a motion is induced by pain; but if the
middle link be destroyed, the connexion between the first
and second with the consciousness ceases. We believe also
that the reflected motions on stimuli of the skin, which take
place after the removal of the brain, do not contain any proof
that the stimulus excited true sensation in the spinal mar-
row ; it is rather the centripetal conduction of the nervous
principle which commonly takes place in sensations, but which
here is no longer sensation, because it is no longer con-
ducted to the brain, the organ of consciousness. During
healtli also numerous reflected motions result from stimuli of
the skin, which do not come as true sensations to the con-

* There may certainly be considerable doubt respecting the action of the
cesophagus — a doubt which nothing but careful experiment can solve. But
1 think I have proof that the cardia closes and opens upon the principle of
the reflex function, as well as the pharynx, and that it is under the influence
of the internal excito-motoryf or pneumogastric nerve. — M. H.

on the Rejlejc Function of the Spinal Marrow, 189

sciousness, but still may excite violent impressions on the
spinal marrow ; as, for instance, the permanent contraction of
the sphincters from the stimulus of the excrement and of the
urine. But Dr. Marshall Hall goes too far, when he sup-
poses that in health every motion on true sensation is induced
by the will, and that all excitations of sensitive parts in the
reflected motions are without sensation. For the reflected
motions of sneezing, coughing, and many others follow actual
sensations*.

" The reflected motions, and the involuntary not reflected
motions are not to be confounded with one another. If the
rima glottidis of an animal be touched, says \^i\ Marshall
Hall, a contraction takes place ; the same, when the heart is
touched. By removal of the brain no alteration ensues ; but
if the medulla oblongata be removed, the contractions of the
larynx on stimuli cease, while those of the heart continue. The
action of stimuli on the heart is an immediate one dependent on
its irritability; a stimulus applied to the larynx must, on the
contrary, be propagated to the medulla oblongata, and the con-
traction results indirectly from it. In a snake after the removal
of the head a motion of the larynx ensued ; it was drawn down-
wards and closed, as soon as Dr. Marshall Hall touched a spot
within the teeth of the lower jaw or the nasal apertures. After
removal of the medulla oblongata this ceased. Lastly, he men-
tions as belonging to the reflex function, the winking of
the eyelids when they are touched; the peculiar action on the
respiration by tickling, or when cold water is thrown into the
face; sneezing from stimuli of the nasal mucous membrane;
cough; vomiting from stimuli of the larynx or pharynx; te-
nesmus from stimulation of the rectum ; and strangury from
that of the bladder. We see that the spasms in diseases may
have very different sources. There are, for instance, spas-
modic affections which have their seat in the motor nerves
themselves, and others which have their cause in the brain
and spinal marrow ; but there are also reflected spasms, whose
cause lies in stimulation of sensitive nerves, as those which often
take place after intestinal stimulation, in dentition, odontalgia,
and painful nervous affections from organic and inorganic
lesions generally.

" The phenomena which we have now described, first from
our own observations and then from those of Dr. Marshall
Hall, have all this in common with one another, that the spinal

* These and other acts of the excito-motory system are attended by sen-
sation, but are not the less independent of it ; some are entirely without it.
— M. H.

190 Prof. Mliiler and Dr. Marsliall Hall

marrow is the connecting link between a sensoiial and a mo-
torial motion of the nervous principle, though still the course
which the conduction in the reflected motions from the sen-
sitive to the motor nerves in the spinal marrow takes may be
more definitely pointetl out. The most common kind of re-
flected motion is, that the muscles of a limb, in which violent
sensations have been excited, may be moved, as in the burning
of the skin twitchings take place in the burned limb ; or as in
the commencement of the narcotization of an animal, on the
sensitive stimulus of the skin the muscles of the stimulated
limb are most easily moved ; or as the morsels of food produce
the reflected motion of the apparatus for swallowing; or as the
particle in the conjunctiva exciting merely sensation, produces
the reflected closure of the eyelids; or as, lastly, the stimulus
of the urine and excrement act indirectly on the motion of the
sphincters. As soon therefore as the sensitive- motion has
reached the spinal marrow, it does not pass over the whole
spinal marrow, but most easily to those motor nerves which
have their origin nearest to the stimulated sensitive nerves ; or
in other words, the easiest way for the current or vibration is
from the posterior root of a nerve or some of its primitive fila-
ments to its anterior root, or to the anterior roots of several
adjacent nerves. We see, then, that the nervous principle in
these currents or vibrations takes the shortest way, acting from
sensitive fibres through the medulla spinalis on motor fibres;
just as electricity takes the shortest way from one pole to
the other. More correctly expressed, and translated into
physiological language, this means, that in violent excitation
of the motor property of the spinal marrow through a sen-
sitive nerVe, that part only of the spinal marrow is first ex-
cited, and then excites movements, which gives origin to the
sensitive nerve ; and that the excitation of other parts of the
spinal marrow, and the motor nerves arising therefrom, decreases
in proportion as they are more removed from the spot excited
by the sensitive nerve. The same holds also of the cerebral
nerves, whose reflected phenomena appear to remain still
almost quite unknown to Dr. Marshall Hall*. The great
nerves of the senses are especially prone to cause reflected
motions of the motor cerebral nerves, and especially the op-
tic and auditory; they produce in vivid light and on loud
sound a reflected excitation of the facial nerve, and thereby
closure or winking of the eyelids. The optic nerve again
easily produces the reflected excitation of the oculo-motor
nerve in motion of the iris, and on looking at bright light it in-

* 1 am still of opinion tliat the reflex function is confined to the medulla
oblongata and spinalis, exclusively of the brain. — M. H.

on the Reflex Function of the Spinal Marrow, 191

duces a reflected affection of the facial and other nerves in
sneezing. But the great sensitive nerve of the anterior part
t)f the head and the face, the great portion of the trigeminus,
may excite the oculo-motor and facial through the medium of
the brain ; thus contraction of the iris takes place when cold
water is thrown into the nose, and from tickling in the nose
sneezing takes place, as well as the action of the facial nerve in
theexcitementofthe facial muscles which is connected with it. In
sliort, we see, that of the motor cerebral nerves, the part of the
oculo-motor nerve which goes to the ciliary ganglion and
thence to the iris, and the facial nerve, may most easily be ex-
cited by reflexion, and that the impressions either of sight, or
touch, or hearing maybe the exciting causes: therefore between
the origins of the optic, trigeminus, and auditory nerves, and
the points of origin of the motor nerves in the brain, there
must be a facility of conduction pre-established by primitive
formation. Those sensitive and motor nerves, whose mutual
action is effected through the brain and spinal marrow, pre-
sent a kind of balance with those central parts, one altering
the other, as the ascent of one scale induces the descent of the
other, or as the falling of a fluid in one leg of a bent tube pro-
duces the ascent in the other, till they are permanently at an
equilibrium. If a sensitive nerve is not usually in a state to
produce a reflected motion, yet on any violent impression on
sensation it becomes so, and the brain and spinal marrow then
reflect the currents or vibrations received from the sensitive
nerves, into those motor nerves, to which the conduction from
the sensitive fibres through the fibres of the brain and spinal
marrow is most easy.

"Another very common path of conduction from the sensi-
tive to the motor nerves through the medium of the spinal
marrow and medulla oblongata, is that seen in the excitation of
the mucous membranes aiid the secondary affection of the re-
spiratory muscles in vomiting, evacuation of faeces, parturition,
the coughing, sneezing, &c. Next to the above-mentioned law,
that nerves of allied origins, or of not very remote origins, are
peculiarly prone to the phenomena of reflexion, the most fre-
quently acting law of the "Nervenstatik" is the reflexion now
mentioned. Therefore, i?i the medulla oblongata and spinal
7narro'w, between the sensitive nerves of the mucous membranes
(the trigeminus in the nose; the vagus in the trachea,- lungs,
pharynx, oesophagus, stomach ; the sympathetic in the intes-
tinal canal and uterus; branches of the sacral plexus and sym-
pathetic in the urinary bladder and rectum ;) and the motor
respiratory nerves (facial, accessory, and spinal nerves), there
must be pre-formed easy means (or a conduction; while, on

192 On the Reflex Function of the Spinal Marrow,

the contrary, the spinal nerves going to the extremities are
excluded from this harmony.

" But if a certain irritation of the spinal chord and brain be
induced by narcotism or other causes, then every perception
may produce a discharge of the spinal marrow to all the
motor nerves, even to those which are affected with the great-
est difficulty, viz. the motor nerves of the extremities." (pp. 688
-—701.)

Such is the account of this subject given by Prof. Mliller.
I may be allowed to repeat that I have perused this unpreju-
diced and independent testimony to the importance of my in-
vestigations with unmingled satisfaction.

Before I dismiss the subject, I must add that my views are
somewhat different from those of Prof. Miiller :

1. I view the reflex function as the distinct and peculiar or
proper function of the medulla spinalis, equally independent
of the brain, the sympathetic, and of the anastomoses and the
mere origins of nerves ;

2. I regard this function as residing in the medulla, as the
axis of a distinct system of excitor and motor, and excito-mo-
t07-y nerves ;

3. I consider this function and its system of nerves as pre-
siding over the orifices and the exits or sphincters of the ani-
mal frame, and over ingestion and egestion ;

4. The brain is the central organ of sensation and voli-
tion, the organ of mental relation with the external world ;
the spinal marrow, on the contrary, is the central organ of
excito-motory phenomena, and o^ i\\e physical appropriation of
certain external objects ;

5. Respiration even is a part of this peculiar function : it is
excited on ordinary, and on extraordinary occasions, through
appropriate excitor nerves, especially the pneumo-gastric,
but also the fifth and spinal nerves;

6. Volition may modify the acts of the reflex function, and
these acts may be attended by sensation ; but this function is,
otherwise, independent both of volition and sensation, of
their organ the brain, and of the mind or soul;

7. The passions^ in an especial manner, demonstrate them-
selves through the medium of the true spinal marrow ; and thus
pain may induce surprise or fear, and appear to occasion an

excito-motory act ;

8. The brain sleeps', but the spinal marrow never sleeps;

9. Finally, the excito-motory system of nerves are the pe-
culiar seat of action of certain diseases, and of certain causes and
remedies of disease.

These and other propositions I ani about to illustrate in a

Mr. Rainey's Analysis 9/ Dr. Ritchie's Hephj. 193

series of papers preparing for the Royal Society. That they
involve a principle in physiology at once extensive and novel,
will not, I think, be now denied.

1 may add that in some of the Invertehrata, the necessity for
the nerves being intervertebral not existing, the excito-motory
system of nerves, with their axis, may be as distinct in their
anatomy as they are in their functions. This question I am
about to subject to the test of experiment.

14, Manchester Square,
November 25, 1836.

XLIII. An Analysis of Dr. Ritchie's Paper, in reply to Mr.
Rainey's last Commiinicatio7i concerning Magnetic Reaction,
contained in the Philosophical Magazin^ for January, By
G. Rainey, M.KC.S.'"

T^HAT Dr. Ritchie is in error will be clear from the fol-
-■- lowing facts. The expression most frequently employed
to explain the action of a magnet upon its keeper is, that the
magnet induces on the contiguous ends of the armature op-
posite states of magnetism, and that in consequence of this
dissimilarity these oppositely magnetized extremities attract
one another, evidently inferring that attraction follows as a
consequence of induction. If a piece of soft iron be applied
to magnets of different magnetic intensities, the adhesion would
most undoubtedly be the greatest between the soft iron and
the strongest magnet; and if any other magnet still stronger
were applied to the same keeper, this increase would be mani-
fested by a still more forcible attraction of this keeper by the
magnet; and so on, without any known limit : consequently, as
attraction is the effect of induction, the induction may be in-
ferred to have no known limit, and the position to be true.

Dr. Ritchie says, " he, Mr. Rainey, also takes for granted,
that a magnet having double the power will induce in the same
armature twice the effect." I am not conscious of ever having
made such an assertion.

Dr. Ritchie, to refute my first position and the one incor-
rectly attributed to me, has invented the following experiment:
'* Roll a covered wire about the half of an electro-magnet
A B. Do the same with an equal wire from C to D. Connect
the first helix with an elementary battery, and ascertain the
lifting power of the magnet. Connect the other helix with an
equal battery, and instead of the lifting power being doubled,
according to the principle assumed by Mr. Rainey, its power

• Communicated by the Author.
Third Series, Vol. 10. No. GO. March 1837. 2 C

19'k Mr. Rainey's Analysis ofDr, Ritchie's Reply,

may notbe increased a third or a fourth, or even a tenth, if the
battei-y be a powerful one." — See Phil. Mag., January, p. b9>.

From this experiment Dr. Ritchie not only endeavours to
convince every person of the absurdity of my views, but so
deeply is he impressed with the correctness of its indications
that conclusions are deduced from it even with arithmetical
precision.

Dr. Ritchie must know that if a bar of iron be under the
influence of a galvanic current, the magnetism will accu-
mulate in those parts of the bar nearest to the extremities
of the wire, and that the part of the bar opposite the middle
of the coil will be magnetically inactive; consequently when
one leg was magnetized it would have two poles, and that pole
adjacent to the inactive leg of the magnet would induce in it
also polarity ; consequently there would be two magnets in-
stead of one. If the two coils were in action at the same time,
each leg would be a separate magnet, and the magnetical con-
dition of the intermediate curved part would depend upon the
directions of the coils, and it might be a magnet also; conse-
quently there would be three magnets together, the power of
each being very uncertain. How far an experiment like this
is calculated to furnish scientific truth, 1 must leave to the
decision of your readers.

I now come to what Dr. Ritchie designates the second false
principle. This is first called an assumption, and afterwards
a deduction. This part of the subject relates to the reaction
of the keeper upon the magnet. It was the subject of my first
short paper, but has been discussed more fully in the subse-
quent ones.

The following experiments are directly connected with
magnetic reaction, and are, I think, illustrative of tlie exist-
ence of such a property. Take two keepers of the same form.
I>et tiie one consist entirely of soft iron, and the ends of the
other be made of iron, but the intermediate part of brass, as

in the annexed diagram i rz;/«i^S- — i ; apply these keepers

separately to the extremities of a hard single horseshoe mag-
net well magnetized, and it will be found that the iron one
holds, as nearly as can be estimated, double the weight of the
iron and brass one. It will be perceived that the interrupted
keeper will have its attractive force dej^endent entirely upon
the induction of the poles of the magnet, and that the weight
sustained will be a correct measure of the sum of the attraction
of the poles, whilst the uninterrupted keeper will have its at-
traction doubled by the induction which takes place in con-
sequence of the action of one end of the keeper upon the

on the Phanomena of Magnetic Reaction. 195

other. On extending this experiment to compound magnets,
I was at first surprised to find that the attraction of the or-
dinary keeper exceeded that of the interrupted one by con-
siderably more than double. These keepers were applied to
two compound magnets, the one having three plates, and the
other five, of about the same size. The interrupted keeper was
attracted nearly the same by each, but the common one was
held much more firmly by the magnet having the greater
number of plates. This brought to my recollection a fact
which liad often appeared very surprising, and for which I
could find no explanation. After taking to pieces a compound
horseshoe magnet consisting of eight blades, and of consider-
able sustaining power, 1 found that the quantity of magnetism
in each blade was very trifling, and apparendy for too little to
account for the attractive power of the entire magnet. These
magnets were each remagnetized to saturation, but the same re-
duction in their power took place on replacing them with their
similar poles in contact. They were made of very soft steel,
and after having their extremities hardened they lost much
less by the contact of their similar ends: this improvement was
not so perceptible on the application of the keeper to the whole
magnet as to the individual parts. The explanation of these
facts appears to be as follows : When magnets are placed with
their similar poles in contact, they lose a considerable quantity
of their magnetic influence. The absolute amount of loss will
depend upon the temper of the steel; the harder it is the less
it will lose : and also upon the number of magnets ; the more
there are the less will each magnet retain. Now, if the inter-
rupted keeper be applied to a compound magnet, it will be
attracted only with a force equal to the quantity of residual
magnetism, which being very small the attraction will be com-
paratively feeble, though probably a correct measure of the
absolute strength of the magnet. When the common keeper is
applied, it will be obvious, from the double source of induction
by which it is influenced, that its state of magnetism will exceed
that of the weakened magnet, and by reacting upon it increase
its power. The magnet having thus acquired an addition of
magnetism will now react more forcibly upon the keeper, and
the keeper in its turn upon the magnet, and so on, until the
resistance from the contact of the similar poles, and the na-
ture of the steel, cease to allow of any further induction from
this source. The softness of the steel and the number of magnets
being circumstances which favour the reaction of the keeper
upon the magnet, are facts corroborative of the probability of
this explanation, and show that the force with which the com-
mon keeper is attracted by a magnet is a fallacious indication

2C2

196 Mr. Rainey's Analysis ofDr, Ritchie's Reply.

of its real power. A practical inference may be drawn from
these experiments, namehv that little advantage is gained by
the association of magnets, unless their hardness be such as
to prevent the dissipation of so large a portion of their mag-
netism in consequence of the contact of their similar poles.
Dr. Ritchie says that I have taken for granted that the action
of a galvanic current upon a steel magnet is the same, whether
its poles are connected by an armature or not. Certainly so far
as the identity refers to the nature of the eflect produced,
there can be no occasion to entertain any doubt. The usual
results of a galvanic current, such as polarity, &c., are precisely
the same in each case, varying only in degree. It is the ex-
planation of the difference in the quantity of effect of the gal-
vanic current upon the steel when the poles are connected,
and when separated, which forms the subject of discussion in
n)y paper, and which has been attributed to the reaction of
the keeper; therefore, so far from having adopted this as an
axiom, I have endeavoured to deduce it as a consequence.

The last experiment which Dr. Ritchie adduces, p. 59, which
is to set the matter at rest, is a very singular one. " Take a bar
of steel, and bend another of the same size and length into
a square; magnetize the straight bar by drawing it lengthwise
over one of the poles of a magnet ; move the same pole the
same number of times round the square; break the bar into
four equal parts, and the square at the corners, and the bar
C D will be stronger than either [any is meant) portion of the
straight bar." It will be obvious upon a little reflection, that
in the process of magnetizing a closed circuit, of any form
whatever, one part of the steel composing the circuit will act
as a keeper to the other, and consequently that the bar thus
magnetized is under the same circumstances as a horseshoe
magnet would be when magnetized with a piece of iron in
contact with its poles. Hence we see that Dr. Ritchie's square
was under circumstances much more favourable for securing
its full complement of magnetism than the bar was; therefore it
is not to be deemed a matter of wonder that it was found to be
so much stronger. The most curious part of this experiment
is the laborious task of cutting each into four exactly equal
parts; why, if Dr. Ritchie had found that the bar which had
been bent was stronger than the straight one, surely he
might have inferred that the parts of which the bent bar was
made up would be stronger than those corresponding to
them in the straight bar, and that the most troublesome part
of the experiment might have been dispensed with. It is also
equally strange why Dr. Ritchie should have chosen an exact
^(juare as the form necessary for the closed circuit. Does not

Prof. Forbes on the Physical Development of Man, 197

Dr. Ritchie know that tlie figure into which the bar might
be bent would have nothing at all to do with the disposition
of the nia<;netism throunli the metal? Of whatever form the
bar might be, the instant the continuity was destroyed the
magnetism would accumulate at the most remote extremities
of the bar, leaving the centre inactive or neutral if the bar
had been properly magnetized, and of the same form and den-
sity the neutral point would be exactly in the middle ; the
figure of a square having no influence whatever in making it
otherwise.

As I am obliged to abridge my remarks as much as possible,
I sliall conclude my paper with this experiment, leaving your
readers to judge of tlie merits or demerits of this discussion.

XLI V. On the Results of Experiments made on the Weight,
Height, and Strength of above 800 Individuals. By James
D.Forbes, Esq., F.li.SS. L. <$' E., Professor of Natural
Philosophy in the University of Edinburgh.'^

T^HE interesting and remarkable experiments published by
M. Quetelet, of Brussels, on various points of physical
development in man, under a variety of circumstances, as to
climate, station, age and sex, induced me to take the oppor-
tunity which my professional position presented of obtaining
the measure of physical development as to the weight, height
and strength of natives of Scotland between the ages of I4j
and 25, students in our University.

In the prosecution of this plan separate lists were kept
of persons not born in Scotland, and of these, the English and
Irish lists have likewise been subjected to calculation. Though
of these the numbers are comparatively small, the results pre-
sent some pretty decisive characters. These experiments were
continued during two winters (1834-5, 1835-6) : every expe-
riment was made by myself and noted down by myself. The
weights were ascertained by Marriotts spring balance, which
was verified from time to time and found to have undergone
no change in its elasticity. The weight of clothes is in-
cludedf . The heights are in English inches, shoes included.
For the measure of strength, Regnier's dynamometer was
employed, and these experiments were somewhat less satis-
factory than the others. The error of the instrument had

• Read to the Royal Society of Edinburgh : and communicated by the
Author.

t According to Quetelet, this amounts to x'sth of the weight.

198 Prof. Forbes*s Experiments on the Weight,

been ascertained before the commencement of the experiments,
anil was fonnd to be pretty constant throughout the scale.
But after the experiments were finished this was by no means
the case, the error having become variable owing to the inter-
fering action of a small spring employed to bring the index to
zero. As this, however, only aftects the absolute results (or,
at least, its relative influence is trifling), I have contented my-
self with applying an interpolated correction deduced from
the mean of the errors before and after, which cannot differ
much from the truth. But the instrumental errors are not
the only ones to be contended with. To avoid errors in the
use of the dynamometer requires vigilant superintendence on
the part of the observer; and as the first pull is generally
(though not always) greater than the second or third, this
also must be allowed for. I have invariably repeated the ex-
periment three times, and often much more frequently. When
extraordinary cases have occurred I have taken the precaution
of observing at distinct intervals of time.

In ascertaining the mean results the following method has
been adopted: the natives of each country were separated,
and each class divided, according to age, into twelve sets, from
14? to 25, the greatest number being of the age of 18 years.
The mean weight, height and strength for each year was com-
puted, and the result projected upon ruled paper. Curves
were drawn through the points thus projected, in such a way
as to represent most satisfactorily the whole observations.
These curves, with the determining points, are now exhibited
to the Society. It is proper to add that the ages registered
being the ages at last birthday, the weight, &c., registered is
not that due to the age noted, but at a mean to an age half a
year later. Thus all the persons who were 20 last birthday
are between the ages of 20 and 21, or 20^ at a mean. This
has been attended to in making the projections.

Besides the English, Scotch and Irish curves, I have exhi-
bited those of the Belgian development, from M. Quetelet's
experiments, reduced to English measures. The thickness
of the shoes not being included in these experiments, half
an inch (perhaps too little) has been added to make them
comparable with the others. It is important to add that M.
Quetelet's experiments here quoted, as well as my own, were
made upon persons in the higher ranks of life, in both cases,
in fact, upon persons having the benefit of academical instruc-
tion.

The number of persons examined by me in the two winters
before stated was thus divided : Scotchmen, 523 ; Englishmen,
178; Irishmen, 72; from the Colonies, &c. 56', total, 82y.

Height and Strength of above 800 Individuals, 199

I was careful to obtain a fair average of persons of all degrees
of height and strength, in which respect the Scotch average is
more unexceptionable than the others. There is always a ten-
dency in such cases to get too high a development, because
diminutive persons are the least likely voluntarily to come for-
ward. An example of this is found in the mean height ob-
tained by M. Quetelet, from a register of 80 individuals at
Cambridge between the ages of 18 and 23, giving a mean of
69*6 inches instead 68'7 as my experiments indicate.

The numerical results derived from the graphical process
before described are given at the close of the paper, and seem
to warrant the following conclusions :

1. That in respect of weight, height, and strength there is
a general coincidence in the form of the curves with those of
M. Quetelet.

2. The British curves seem to have more curvature for the
earlier years (14« to 17)j or the progress to maturity is then
more rapid, and somewhat slower afterwards. If we may de-
pend upon the English curves, this is more strikingly the case
in natives of that country than of Scodand, at least in point of
weight and strength.

3. The tables incontestibly prove the superior development
of natives of this country over the Belgians. The difference
is greatest in strength (one fifth of the whole) and least in
weight.

4. In comparing natives of England, Scotland, and Ireland
more doubt arises, owing to the difference in the number of
experiments; those for Ireland are confessedly most im-
perfect. Yet I conceive that the coincident results in the
three tables entitle us to conclude that the Irish are more de-
veloped than the Scotch at a given age, and the English less.
Some qualification is, however, due, in consequence of the re-
mark (2.); for in the earlier years (14 — 17) it would even ap-
pear that the English so far get the start of the Scotch, as not
onl}' relatively but also absolutely to surpass them (in strength
and weight) ; but between 17 and 19 they lose this advantage.
I am disposed to think that this appearance of a result is not
accidental.

5. The maximum height seems scarcely to be attained even
at the age of 25. This agrees with M. Quetelet's observations.
Both strength and weight are rapidly increasing at that age.

6. In the given period of life (14 — 26) all the developments
continue to increase; and all move slowly from the com-
mencement to the end of that period. Hence the curves are
convex upwards. [This is not the case below the age of 14,
for weight and strength. Quetelet. J

SOO Prof. Forbes on the Fhysical Development of Man.

Tables.
Weights in Pounds (including clothes).

Age.

English.

Scotch.

Irish.

Belgians.

15

114-5

112

102

16

127

125-5

129

117-5

17

133-5

133-5

136

127

18

138

139

141-5

134

19

141

143

145-5

139-5

20

144

146-5

148

143

21

146

148-5

151

145-5

22

147-5

150

153

147

23

149

151

154

148-5

24

150

152

155

149-5

25

151

152-5

155

150

Heights in inches. Full dimensions (with shoes),

Age.

English.

Scotch.

Irish.

Belgians.

15

64-4

64-7

61-8

16

m-5

66-8

....

64-2

17

67-5

67-9

....

661

18

68-1

68-5

68-7

67-2

19

68-5

68-9

69-4

67-7

20

68-7

69-1

69-8

67-9

21

68-8

69-2

70-0

68-0

22

68-9

69-2

70-1

68-1

23

68-9

69-3

70-2

68-2

24

68-9

69-3

70-2

68-2

25

68-9

69-3

70-2

68-3

Sti

ength in

Pounds.

Age.

English.

Scotch.

Irish.

Belgians.

15

280

204

16

336

314

....

236

17

352

340

369

260

18

364

360

389

280

19

378

378

404

296

20

385

392

416

310

21

392

402

423

322

22

397

410

427

330

23

401

417

430

335

24

402

421

431

337

25

403

423

432

339

[ 201 ]

XLV. On an Artificial Substance resembling Shell, Bj/
Leonard Horner, Esq.y F,R,SS. LomL and Edinb. With
an Account of an Examination of the same. By Sir D win
Brewster, LL,D., RR.S., ^c*

'll/'HILE I was, some time ago, officially inspecting the cot-
^^ ton-factory of Messrs. J. Finlay and Co., at Catrine, in
the county of Ayr, on going over the bleaching-establishment
attached to it, I was struck with an unusual appearance of a
part of the machinery, which, at a distance, looked as if it were
made of brass. On a closer examination, I found that it was
a large circular wooden box coated with an incrustation of a
brown compact substance, having a highly polished surface,
a metallic lustre, in some places beautifully iridescent, and
when broken exhibiting a foliated texture f. This resemblance
in structure and pearl}' lustre to some species of shells, such
as the Meleagrina, Malleus^ Avicula, Ostrea^ Pinna, and others,
induced me to examine the substance more closelj', conceiving
that it might possibly throvv some light on the formation of
shell.

The part of the machinery on which I observed the incrus-
tation is called a Dashwheel, and consists of a circular box,
about seven feet in diameter and three feet in width, revolving
upon a horizontal axis, and having its interior divided into four
compartments, into each of which there is a circular opening
on one side. The purpose of this wheel is to wash or rinse
the cloth in pure water, after it has been boiled or steeped in
the bleaching-liquors. It makes twenty-two revolutions in a
minute, which is found to be the proper degree of speed, in
order that the cloth may be tossed about and dashed against
the sides as the wheel turns ; a greater velocity causing it to
keep at the circumference without shifting its position.

1 was told that the incrustation was a deposit of carbonate
of lime, and the source of the lime was mentioned. But
whence the brown colour, and the metallic nacreous lustre?
If the substance were analogous to shell, it ought to contain
animal matter ; and whence could that be derived ? It was
necessary to trace the operations from the beginning.

The cotton cloth is brought to the bleach-field in the state
in which it is taken from the weaver's loom. The first process
is to steep it in water for several hours, after which it is im-
mersed in cream of lime. This is made in the following man-
ner ; fresh-burned lime is slaked and passed through a fine

• From the Philo«opliical Transactions for 1836, p. 49.
t Specimens arc deposited at the British Museum.
Third Series. Vol. 10. No. 60. March 1837. 2 D

202^ Mr. Horner and Sir David Brewster on

sieve, and added to water in the proportion of 38 lbs. of dry
lime to 1000 lbs. of cloth. The cloth is boiled in this liquor from
four to six hours, the lime acting as an alkali; and it is used
only from being consitlerably cheaper than potash or soda.
After this boiling, the cloth is taken to the dash-wheel to be
thoroughly cleared of the lime, which is effected by its being
tossed about for ten minutes in clear water in the interior of
one of the compartments into which the wheel is divided.
Here, then, is the source of the calcareous matter of the in-
crustation ; and we have the lime dissolved or suspended in
the water in a state of extremely minute division, and from
which it is deposited, most probably, by a partial evaporation.
It is difficult to say whether the deposit takes place while the
wheel is revolving, by the water being broken into a kind of
spray, and so presenting a greater surface for evaporation, or
during the night, when the wheel is still : some of the proper-
ties, to be afterwards described, render the latter supposition
the most probable. But in whatever way it takes place, the
operation is an exceedingly gradual one ; for the wheel had
been in constant use for ten years, and the coating in the inte-
rior did not exceed one tenth of an inch in thickness. It had
been in operation about two years before any perceptible depo-
sit showed itself in the inside ; but it had not been going half a
year before an incrustation began to be formed on the outside
of the wheel. I remarked that the deposit was in greatest
quantity around the orifice where the cloth is put in and taken
out. llie deposit in the interior, and which coated the whole
surface of the compartment, was of a darker brown colour,
and was as smooth and splendent as a lining of highly polished
bronze would have been. The high polish is no doubt partly
produced by friction ; and I observed that it was highest on
that part of the outside nearest the opening.

So far we have calcareous^ but no animal, matter; but in
going a little further back in the history of the process to which
the cotton had been subjected, before it came to the bleach-
field, I discovered that animal matter might be contained in
the incrustation. I learned that the cloth had been woven
in power-looms ; and on making inquiry as to the composition
of the dressing or paste used to smooth and stiffen the warp be-
fore it is put into the loom, I was told that in the factory from
whence the cloth had come, it is the practice to mix glue with
the wheaten flour, generally in equal proportions by weight.

We have thus lime and gelatine, the same materials which
are employed by the molluscous animal in the formation of its
covering, and apparently in the same degree of minute divi-
sion as that in which they are exuded from its mantle.

a?i artificial Suhstajice resemhliiig Shell, 203

Chemical examination of the Substance.

1 . The external deposit, — Exposed to the flame of a wax
candle, it blackens, and gives out the usual smell of burning
animal matter, the thin laminae of which it is composed sepa-
rating and curling up like films of horn ; appearances similar
to those exhibited by membranous shells when heated. When
the flame is urged by the blowpipe, the laminae separate still
more, and are changed into an extremely light and brittle
enamel, pure white, and having a pearly lustre. A fragment
moistened on the back of the hand gives a sensation of heat, as
quicklime does when so treated. The substance, when thrown
into dilute muriatic acid, is entirely dissolved; the fluid is
tinged yellow, and the effervescence produces a froth, like beer.
When the acid is very much diluted, and a portion of the sub-
stance is suspended in it, the solution takes place gradually,
minute flocculi of animal matter being separated, and floating
in the fluid.

2. The internal deposit, — This is separable into extremely
thin laminae, and these, when in small fragments, are hardly
distinguishable from scales of brown mica, showing also the
most beautiful play of colours. The action of heat produces
the same effect as on the external deposit, except that the sepa-
rated laminae are thinner. The action of muriatic acid is the
same, but the yellow tinge is deeper, and the froth is more
permanent, indicating a larger proportion of animal matter than
in the other. The nacreous lustre is also much more conspi-
cuous in this.

Mr. Gray, in his paper on the Structure of the Shells of
Molluscous Animals, observes that the pearly or iridescent
lustre appears to be confined to shells of the concretionary
structure, which when broken exhibit a nearly uniform texture,
but separate when heated into numerous thicker or thinner
laminae ; and he adverts to the observation of Mr. Hatchett,
that when they are digested in weak muriatic acid, the lime is
dissolved, leaving a great number of thin plates of animal mat-
ter, which retain the original shape of the shell. He adds,
'' This variety of structure is found to constitute the whole
shell of the Anomice and Placuncc^ and to form the inner coat of
those shells which have pearly insides, as the Turbines, Ha-
liotides, Uniones, &c., as well as the laminar portion of the
Pinnce and Mother-of-pearl shells *,"

Besides the laminated structure, there is, in the case of the

* Phil. Trans., 1833, p. 794. [An abstract of Mr. Gray's paper here re-
ferred to will be found in Lond. and Edinb. Phil. Mag., vol. iii. p. Ab2.
Mr. Hatchett's paper was reprinted entire in Phil. Mag., First Series, voJ, vi-
p, 31. —Edit.]

2 D 2

204 Mr. Horner and Sir David Brewster on

Pinna and some other shells, a prismatic crystalline arrange-
ment of the particles perpendicular to, and passing uninter-
ruptedly through, the laminae ; but I have not discovered such
an arrangement in any portion of the incrustation, even when
examined by the microscope.

1 felt very desirous that this singular deposit should be ex-
amined by Sir David Brewster; the more especially as he had
long since directed his attention to the peculiar structure of
mother-of-pearl *. On showing him the specimens in my pos-
session he observed, that it was one of the most remarkable
artificial productions he had seen; and he readily undertook
to examine it carefully. He shortly afterwards sent me the
particulars of that examination, which had afforded some cu-
rious and interesting results. Having subsequently visited
Catrine, I procured more perfect specimens ; and I sent these
to Sir David Brewster, in order to ascertain whether they
might not afford something new, in addition to the results he
had obtained from the fragments he had formerly examined.
They did so, and I now subjoin the very interesting account
which Sir David has given me of the properties he has disco-
vered in this new substance.

My dear Sir, Belville, Jan. 1st, 1836.

In the communication which I had the pleasure of address-
ing to you on the 20th of January, 1835, I gave a brief ac-
count of the observations I had made on the highly interesting
substance which you had put into my hands ; but as the spe-
cimens which you sent me a few days ago are so much supe-
rior to those with which I made my former experiments, and
have led me to some new and I think rather extraordinary re-
sults, I shall include in the present letter all my former obser-
vations.

The substance in question does not resemble in its general
aspect any natural or artificial production which I have seen.
It is, generally speaking, brown where the surface is not iri-
descent, and in very thin plates : it is almost perfectly transpa-
rent, with a slight yellowish brown tinge like plates of glue or
lac of the same thickness. The laminae of which it is com-
posed are sometimes separated by vacant spaces, at other times
slightly coherent, but generally adhering to each other with a
force greater than that of the laminae of sulphate of lime or
mica, and less than those of calcareous spar. When the ad-
hering plates are separated, the separated surfaces are some-
times colourless, especially when these surfaces are corrugated
or uneven ; but they are almost always covered with an iri-
descent film of the most brilliant, and, generally, uniform tint,
• Phil. Trans., 1814.

an artificial Substance rese7nbling Shell, 205

which exhibits all the variety of colours displayed by thin
plates or polarizing laminae.

The substance is of intermediate hardness between calca-
reous spar and sulphate of lime. It scratches the latter easily,
and is not scratched by mother of-pearl. Its specific gravity
is shown in the following Table, which indicates its relation to
analogous substances.

Calcareous spar 2*72

Oriental pearls 2*6S

New substance 2*44?

Mother-of-pearl ,.,, „. 2-19

Oyster-shell 2*02.

The new substance has the property of r^racting light
doubly, like most crystallized bodies; and, a^ in agate, mother-
of-pearl, &c., one of the two images is perfectly distinct, while
the other contains a considerable portion of nebulous light,
varying with the thickness of the plate and the inclination of
the retracted ray. It has one axis of double refraction, like
calcareous spar, which is negative, as in that mineral, and, like
it also, it gives a beautiful system of coloured rings by polar-
ized light. The double refraction of the substance is very
considerable, though greatly less than that of calcareous spar.
A plate, one seventy-fifth of an inch thick, makes the first red
ring of the system eight inches in diameter at a distance of
twenty-six inches from the eye. The substance belongs to
the rhombohedral system, and, as in the Chaux carbonatee
basee of Hauy, the axis of the rhombohedron, or that of double
refraction, is perpendicular to the surface of the thin plates.
As mother-of-pearl has two axes of double refraction like ara-
gonite, this new substance may be considered as having the
same optical relation to calcareous spar that mother-of-pearl
has to aragonite.

When we look through a plate of this substance perpendi-
cularly to its surface, or along the axis of double refraction,
the flame of a candle is seen encircled with a nebulous haze
like a halo. By the slightest inclination of the plate in any
azimuth whatever, three elongated and curved nebulous images
are seen, as in fig. 1., the central one, A A, having a distinct
image, D, of the candle in the middle of it, and the other two,
B B and C C, being equidistant from A A. These elongated
images are parallel and concave towards the end of the plate
nearest the eye. In the direction of the axis of double re-
fraction, when all the nebulous light is in one mass, the di-
stinct image, D, is redder than in any other direction ; and
by slightly inclining the plate the red light disappears, and the

206

Mr. Horner and Sir David Brewster on

distinct image becomes brighter and whiter. All the three
images, A A, B B, and C C, are

united into a mass round D, at

a perpendicular incidence, but W[

they separate upon inclining the

plate, and their distance increases

with the inclination.

If we examine the nature of

the light of which these images

are composed, we shall find that

the nebulous images, A A, B B,

are wholly polarized in a plane

passing through the direction of

their length, while C C and the

greater part of D are polarized

in an opposite plane. As the

thickness of the plate increases,

more and more of the distinct

image, D, is polarized in the same

plane, as in mother-of-pearl*,

till at a certain thickness the

whole of it is thus polarized.

In this case all the doubly re-
fracted light which forms the ne-
bulous image, A A, and the

bright one, D, consists of two

oppositely polarized pencils, the one forming the nebulous and
the other the distinct image.

In investigating the cause of these phaenomena, we must take
as our guide the analogous facts presented by certain compo-
site crystals of calcareous spar. Having long ago described this
class of phaenomena very fully f , I shall only state at present
the general fact. Let A B C D, fig. 2., be a section of a rhomb
of calcareous spar

having its axis per- Fig. 2.

pendicular to the faces A,

A B, C D, and let E F
be another crystal, or
vein of the same sub-
stance crossing it ac- c
cording to the law of
crystallographic composition. If we now look at a candle
through this compound crystal, it will appear single in the di-
rection of the axis of A B C D ; but if we incline the plate in

♦See Phil. Trans., 1814.

t Ibid., 1815. Edinburgh Encyclopaedia, art. Optics.

an artificial Substance resembling Shell, 207

a plane passing through A B, T* q

we shall see two images together, °'

as at A and D, fig. 3., and otlier b^ A^fto ©c
two, namely, one at B and the ^ ^^ ^

other at C. These images, B, C, separate by the inclination
of the plate exactly like those in fig. 1., and all the four. A, B, C,
and D, have the same absolute and relative polarization as the
four analogous images seen through the new substance, with
this difference only, that none of them are nebulous.

If we conceive the "ii'icr, 4,

vein E F to consist,
as in fig. 4., of a great
number of small cry-
stals, fir, b, c, di &c. in
place of one, the very
same effects will be
produced.

When we look through the new substance, the multiplica-
tion of images takes place in "whatever azimnth we incline the
plate, the elongated images being always perpendicular to the
azimuth of inclination. Hence it follows, that these images
are produced by numbers of minute crystals lying in or near the
azimuth in which the plate is inclined ; and that these crystals
have their axes all inclined to that of the plate which contains
them, at the same angle as the vein E F, figg. 2 and 4, is in-
clined to the axis of the rhombohedron of Iceland spar. But
the remarkable result of these observations is, that in place of
one set of crystals, or sometimes three sets, which occur in cal-
careous spar in three different azimuths, we have here an infi-
nite numbei' of them lying in every possible azimuth, and these
so small in their dimensions that they cannot be recognised by
the most powerful microscopes, except as dark specks disse-
minated through the general mass ; and yet they indicate by
their action on light, not only their existence, but the position
of their axes, and their doubly refracting and polarizing struc-
ture, as unequivocally as if we could handle them, and cle'we
them, and place them upon the goniometer.

It may now be asked why the images are nebulous, and not
distinct as in calcareous spar. The reason is, that the sub-
stance is imperfectly crystallized like the agate, mother-of-
pearl and other bodies in which the doubly refracting force
separates the incident light into two oppositely polarized pen-
cils, which are not perfectly equal and similar, but which dif-
fer from each other, sometimes in the intensity of their light,
sometimes in the distinctness of the image, sometimes in the
nature or brightness of the colour, and sometimes in more

208 Mr. Horner and Sir David Brewster on

than one of these characters. But tliough the new substance
resembles the crystals above mentioned in giving dissimilar
pencils of doubly refracted light, it stands unique among all
bodies with which I am acquainted in possessing the extra-
ordinary system of composite crystallization, in which an in-
finite number of crystals are disseminated equally in every
possible azimuth through a larger crystalline plate, having
their axes all inclined at the same angle to that of the larger
plate, and producing similar phaenomena in every direction,
and through every portion of the plate; or we may describe
this remarkable structure by saying that the minute elementary
crystals form the surfaces of an infinite number of cones whose
axes pass perpendicularly through every point of the larger
plate*.

The iridescent phsenomena exhibited by the new substance
are extremely interesting, and I have been at much pains to
examine them in a great number of specimens. The plates
into which the substance is divisible have been formed in suc-
cession, and certain intervals of time have elapsed between their
formation. In general every two contiguous laminae are sepa-
rated by a thin iridescent film, varying from the three to the
fifty millionth part of an inch in thickness, and producing all
the various colours of thin plates which correspond to inter-
mediate thicknesses. Between some of the laminae no such film
exists, probably in consequence of the interval of time between
their formation being too short; and between others the film
has been formed of unequal thickness, as happens in the oxi-
dations upon steel when they are formed upon or around
hard parts of the metal caWed pins by the workmen.

There can be no doubt that these iridescent films are
formed when the dash-wheel is at rest during the night, and
that when no film exists between two laminae, an interval too
short for its formation (arising perhaps from the stopping of
the work during the day,) has elapsed during the drying or
induration of the one lamina and the deposition of the other."

That these iridescent films are not thin films of the sub-
stance itself, may be inferred from the fact that light is reflected
from their surfaces when they firmly adhere to the laminae
which inclose them. If, for example, we remove or raise up
from a piece of mica a thin film which gives a bright green
tint, and press it again into optical contact with the surface
from which it was separated, it will then cease to exhibit any

* A rude idea of this structure is given by the beautiful cones, or rather
pyramids of microscopic crystals of titanium which I have somewhere de-
scribed as existing within the pyramids of many crystals of amethyst from
the Brazils.

an artificial Substance resembling Shell. 20^

colour, because no light is reflected from its posterior surface;
but if we press it into optical contact with another surface
which has a different refractive power, its green colour will
still be exhibited. It is owing to this cause that the colours
of the oxidations on steel are so distinctly visible^ and that the
analogous oxidations are seen upon glass even before the film
has begun to separate into coloured scales.

The iridescent films in the new substance possess another
source of interest, in so far as they promise to throw a new
light on the origin of the incommunicable colours of mother-
of-pearl, which arise from the interior structure of the shell,
and which cannot therefore be communicated to wax. These
colours have frequently occupied my attention since the year
1814, when I described the phaenomena of the colours com-
municable to wax*; but though I have devloted much time to
the inquiry, I never could obtain a single result worthy of be-
ing communicated to the public. I took plates of mother-of-
pearl that exhibited different bright colours through different
parts of their surface, and by getting the mother-of-pearl
ground away in different places by the seal-engraver's wheel,
I endeavoured to discover the thicknesses atVhich the colours
were produced, and the cause of the capricious variation of
tints which arose from every inclination of the plate: but all
my experiments were fruitless, and I abandoned the subject
as beyond my reach. The phaenomena, however, presented
by the new substance seem to me to disclose the secret of
which I was in quest. The layers of mother-of-pearl are de-
posited in succession like those which are formed upon the
dash-wheel ; and there can be no doubt that the animal whose
mucous secretions form the shell that incloses it, rests occa-
sionally from its toils, and affords a sufficient interval for the
formation of an iridescent film upon the surface of the plate
of shell which it daily deposits. Owing to the firm adhesion
of the successive layers of the shell, we cannot, as in the more
imperfectly formed new substance, separate each stratum in
order to see the iridescent film upon their surfaces ; but we
can easily determine what phaenomena would be produced if
the layers of the new substance were as transparent as those
of mother-of-pearl. If this were the case, we should see,
both by reflected and transmitted light, the combined colours
of all the iridescent films in the plate. When these films
are numerous and flat, and of various thicknesses, the union
of all their colours would form a pearly whiteness by re-
flected light, and when films of a particular colour predomi-

» Philosophical Transactions, 1814.
Third Series. Vol. 10. No. 60. March 1837. 2 E

no Roi/al Society\

nate, both the reflected and the transmitted light would ex-
hibit that prevailing colour : but if their surfaces are undu-
lated as in mother-of-pearl, from the form of the shell and
other causes, — if the iridescent films vary in thickness, and
consequently in colour, — if they are wanting in some parts of
the shell, and abound in others, — and if films of equal thick-
nesses occur in several laminpe in succession, and films of
other thicknesses in other laminae, which must necessarily
take place from the varying and remitting action of the animal
agent, then we shall have the very structure which is necessary
for the production of the incommunicable colours of mother-
of-pearl.

I have no doubt that this is the true cause of the phaeno-
mena which had so long perplexed me; and the results which
I formerly obtained, though I could then attach no meaning
to them, are in perfect unison with the preceding views. In
order, however, to obtain something like an experimental
confirmation of this opinion, I have examined \k\e.fracture of
a mother-of-pearl shell where the laminae have been all de-
posited with considerable regularity, and where their over-
lying edges are exhibited, and I find distinct and positive
proofs of the existence of iridescent films, sometimes green,
and sometimes red in several successive strata.
I am, my dear Sir,

Ever most truly yours,

J3. Brewster*
To Leonard Horner^ Esq.

XLVI. Proceedings of Learned Societies,

ROYAL SOCIETY.

Nov. 17, *' r> ESEARCHES in the Integral Calculus." Part II
1836. ~" JlV By Henry Fox Talbot, Esq., F.R.S.
Having explained, in the first part of his paper, a general method
of finding the sums of integrals, the author proposes, in the second
place, to apply this method to discover the properties of different
transcendents, beginning with those of the simplest nature. With
this view, he first shows its application to the arcs of the circle and
the conic sections j and demonstrates the possibility of finding three
arcs, such that, neglecting their signs, the sum of two of them shall
be equal to the third, though not superposable in any part : an
equality which has been hitherto deemed impossible in the ellipse
and hyperbola, without the addition of some algebraic quantity.

November 24, 1836. — " Investigation of New Series for the Rec-
tification of the Circle." By James Thomson, LL.D., Professor of
Mathematics in the University of Glasgow. Communicated by
Francis Baily, Esq., V.P. and Treasurer R.S.

Roj/al Society. 211

The author obtains formulae by which the ratio of the circum-
ference of a circle to its diameter may be computed with much
greater facility and expedition than by any of the ordinary methods.

A paper was also in part read, entitled, " Inquiries respecting the
Constitution of Salts. Of Oxalates, Nitrates, Phosphates, Sulphates,
and Chlorides." By Thomas Graham, Esq., F.R.S.Ed., Professor of
Chemistry in the Andersonian University of Glasgow, &c. &c. Com-
municated hy Richard Phillips, Esq., F.R.S.

A Report upon a Letter addressed by M. le Baron de Humboldt to
His Royal Highness the President of the Royal Society, and com-
municated by His Royal Highness to the Council, was also read.

Nov. 30, 1836. Anniversary Proceedings. Having inserted the Ad-
dress of H. R. H. the President in our last number, p. 141, we now
complete our report of these proceedings.

Extracts from the Report of the Proceedings of the Council si?ice the
last Anniversary .

The Council, on the 3rd of March, adopted a Report, submitted
to them by the Committee whom they had appointed for considering
the communications from the Treasury and Excise Office, on the
subject of the construction of instruments and tables for ascertaining
the strength of spirits, in reference to the charge of duty thereon, and
ordered it to be transmitted to the Lords Commissioners of His
Majesty's Treasury ; who in acknowledging its receipt, were pleased
to express " their best thanks to H. R. H. the President, and to the
Society, for the obliging manner in which they had met the wishes
of the Board, and to the Committee for the attention they gave to
the subject, and for the valuable Report with which they had fur-
nished that Board."

The Council, conformably with the recommendation of the Do-
nation Fund Committee, have granted £50 from that fund to Pro-
fessor Wheatstone, in aid of the experimental inquiry which he is
prosecuting on the measure of the velocity of Electricity when pass-
ing along a conducting wire.

A letter from Baron Von Humboldt, addressed to H. R. H. the
President, relating to a proposal for the cooperation of the Royal So-
ciety in carrying on an extensive series of magnetical observations,
in various parts of the earth, having been communicated by H. R. H.
to the Council, it was referred to the Astronomer Royal and to
S. H. Christie, Esq., for their opinion thereupon. The Report of
these Gentlemen was ordered to be read to the Society and printed
in its proceedings j and a Committee has been appointed to consider
of the best means of carrying into effect the measures recommended in
that Report*.

Mr. Monk Mason having, in a letter addressed to H. R. H. the
President, offered the Great Vauxhall Balloon for the use of the So-
ciety, a Committee was appointed to take this proposition into con-
sideration and to report thereupon to the Council.

* A Translation of M. de Humboldt's letter will be found in our lait
volume, p. 42. — Edit.

2 E2

212 lioi/al Society,

The Council have awarded a Copley Medal to Baron Berzelius for
his application of the Doctrine of Definite Proportions in Deter-
mining the Constitution of Minerals. To the labours of this distin-
guished chemist^ science is indebted for many of the facts by which the
Laws of Definite Union were established. As early as 1807, soon after
Dalton and Gay-Lussac had made known their views on this vital
branch of modern chemistry, Berzelius commenced an elaborate ex-
amination on the proportions in which the elements of compound
bodies are united, beginning with the salts, and subsequently extend-
ing his researches to all other departments of his science, as well to
the products of organized existences as to those of the mineral
world. The first part of the inquiry appeared in a series of essays in
the Afhandlingar i Fysik, Kemi, och Mineralogie, t. ili. iv. v. and
vi., as also in the Memoirs of the Academy of Sciences of Stock-
holm, for the year 1813. Since that period he has almost constantly
been more or less occupied with researches bearing on, or illustrative
of, the same subject. His numerous analyses of minerals enabled
him at once to elucidate their nature through the light derived from
the laws of definite combination, and at the same time to supply in
the composition of minerals a splendid confirmation of the universa-
lity of those laws. It is for this branch of his inquiry that the Copley
has been awarded.

A Copley Medal is also awarded to Francis Kiernan, Esq., for his
discoveries relative to the Structure of the Liver, as detailed in his
paper communicated to the Royal Society, and published in the Phi-
losophical Transactions for 1833.

Before the researches of Mr. Kiernan, the liver was supposed to
consist of two dissimilar substances, composed of bro-vn pirenchy-
matous granules, contained in a yellow substratum. The relation
of the vessels and excretory ducts to these supposed dissimilar sub-
stances was not known j nor, although ihe organ was considered
to be a conglomerate gland, were the glandules of which it was con-
jectured to be composed, defined in magnitude, shape, or disposition.
Mr. Kiernan's discoveries show that in place of two textures there
exists but one j and that the difference of colour results from the
accidental congestion of one or other of the systems of vessels, which
are found in the liver. Mr. Kiernan has further satisfactorily de-
monstrated the size and limits of the integral glandules of which
the liver consists. He has traced the relation to these glandules of
the different orders of vessels, which are distributed through the organ,
and has explained the mechanism of biliary secretion. He has
shown that all the blood employed in secreting bile is venous ; and
that the origins of the biliary ducts differ in an important respect
from the origins of the ducts of all other glands : inasmuch as they
form a series, not of coiled or branching tubes, but of anastomosing
vessels, constituting a tubular network.

Mr. Kiernan's researches display great industry and ingenuity ;
when foiled by the difficulties which had foiled preceding anatomists, he
applied a principle that had not been thought of before to facilitate
the investigation of structure. Hitherto, however eminent the En-

Royal Society, ^\$

glish have been in physiology, (and the most eminent of physiolo-
gists, Harvey, was an Englishman,) they have been behind the Ger-
mans and the Italians in anatomy. The discovery which Mr. Kier-
nan has made, exceeds in originality, and in importance is scarcely
inferior to, any single anatomical discovery on record. Its originality
consists in this j it may be estimated from the circumstance that
nothing which had been previously done on this subject affords a clue
to what he has found; and the difficulty of the inquiry may be under-
stood from this ; that although many had undertaken it, all had pre-
viously failed. The importance of the facts displayed may be gathered
from the consideration, that they greatly elucidate the morbid
anatomy of the liver, — a part of the human frame, which is remark-
able for the frequency and variety of its diseases, and at the same
time for the facility with which it may be influenced by remedial
agents.

The Royal Medal for the present year, whicK the Council had pro-
posed to give to the most important paper in Astronomy communi-
cated to the Royal Society within the last three years, is awarded to
Sir John Frederick William Herschel, for his Catalogue of Nebulae
and Clusters of Stars, published in the Philosophical Transactions for
1833.

In delivering this Medal His Royal Highness addressed the
Society as follows : —

This, Gentlemen, is the second time that a Royal Medal has been
adjudged to Sir John Herschel, for researches in a department of
Astronomy which has descended to him as an hereditary possession ;
and I believe I may venture to say, that in no case has a noble inhe-
ritance been more carefully cultivated or more enriched by new
acquisitions. The catalogue for which the Royal Medal is now given,
contains a list of 2500 nebulae and clusters of stars, the same number
which had been observed and catalogued by his father, though only
2000 of them are common to both catalogues; the right ascensions
and declinations of all these objects are determined; the general cha-
racter of their appearance recorded ; and all those wliich present any
very extraordinary character, shape, or constitution, of which there
are nearly 100, are drawn with a delicacy and precision which is
worthy of an accomplished artist. It presents a record of those
objects so interesting as forming the basis of our speculations on the
physical constitution of the heavens which are observable in this
hemisphere, which is sufficiently perfect to become a standard of
reference for all future observers, and which will furnish the means
of ascertaining the changes, whether periodical or not, which many of
them are probably destined to undergo. 1 trust, Gentlemen, that a
long time will not elapse before we shall be enabled to welcome the
return of Sir John Herschel to this country, with materials for a
catalogue of the nebulae of the southern hemisphere as perfect and
as comprehensive as that which we are this day called upon to signa-
lize with the highest mark of approbation which it is in our power to
bestow. He will then have fixed the monuments of an imperishable
fame in every region of the heavens.

214 Royal Society.

The Royal Medal for the present year, which the Council had
proposed to give to the most important paper in Animal Physiology
communicated to the Royal Society within the last three years, is
awarded to George Newport, Esq., for his series of investigations
on the Anatomy and Physiology of Insects, contained in his two pa-
pers published in the Philosophical Transactions within that pe-
riod.

Mr. Newport, to whom the Society was indebted in 1 832 for a
very valuable and elaborate anatomical investigation of the nervous
system of the Sphinx ligustri of Linnaeus, and of the successive
changes which that insect undergoes during the state of larva, and the
earlier stages of the pupa state, published in the Philosophical
Transactions of that year, has since prosecuted this arduous and la-
borious train of inquiry, under circumstances of peculiar difficulty,
with extraordinary zeal and indefatigable perseverance. Within the
period of the last three years he has enriched the Transactions with
two papers, in the first of which, read to the Society in June 1834,
he has extended his researches into the structure and arrangement of
the different portions of the nervous system of the same insect, fol-
lowing their successive changes through the remaining stages of de-
velopment to the completion of the imago, or perfect state. He
devotes particular attention to the study of the periods at which
those several changes occur; for he has found that they vary consi-
derably in the rapidity of their progress at different epochs, according
as the vital powers are called into action by external influences, or
as they become exhausted by their efforts in effecting the growth, or
modifying the form of different systems of organs. The labours of
Mr. Newport have determined, with great exactness, those periods,
which had not before been ascertained.

Among the numerous original observations of Mr. Newport on the
arrangement and connexions of the several parts of the nervous
system, the description he gives of the origin and distribution of the
visceral nerve, which he shows to be analogous to the pneumo-
gastric nerve of vertebrated animals, and also of the system of nerves
corresponding to those which have been considered as peculiarly
subservient to the supply of the respiratory organs, are particularly
deserving of notice. In the course of this investigation many new
and important Aicts are brought to light, which had escaped the
observation of Lyonet, Miiller, Brandt and Straus-Durkheim. Mr.
Newport has also traced a remarkable analogy in the origin and dis-
tribution of the two distinct classes of nerves, the one subservient
to sensation, and the other to volition, belonging to insects, with
those belonging to vertebrated animals, and has thus given greater
extension to our views of the uniformity existing in the plans of
animal organization than we before possessed, and which are thus
made to comprehend the more minute, as well as the larger tribes
of the animal creation.

In a memoir on the Respiration of Insects, more recently commu-
nicated to the Society, and of which, at its last meeting in June, the
title only could be announced, Mr. Newport has, with great diligence

Royal Society, 215

and success, investigated the variations occurring in this function in
the different periods of insect development. He has minutely traced
the several changes which the tracheae and spiracles undergo during
the transformations of the insect, and has particularly described the
successive development of the air-vesicles in connexion with the
power of flight. He has given a minute and accurate description of
the system of muscles, both of inspiration and of expiration, of the
Sphinx ligustri ; has investigated their various modes of action, with
reference more especially to the different classes of nerves appro-
priated to these functions ; and has established a distinction in the
offices of these nerves, corresponding to the sources from which they
derive their origin, and presenting remarkable analogies with similar
distinctions in the nerves of vertebrated animals. He has given the
result of a series of original experiments on the products of respira-
tion in this class of animals, and of their variations under diff'erent
circumstances of temperature, of submersion, aijid of confinement in
unrespirable and deleterious gases j and he has deduced important
conclusions relative to the circumstances which govern the proper-
ties of oxygen consumed and of carbonic acid generated. He has
also communicated various results to which he has arrived concerning
the capabilities which insects possess of supporting life during
longer or shorter periods, when immersed in different media.

For the original views presented in these two papers, as well as
for the mass of valuable information they contain, the results of
much laborious and well-directed research in the more difficult de-
partments of the Anatomy and Physiology of Insects, prosecuted
under circumstances which would have repressed the exertions of a
less ardent inquirer into truth, the Council have considered Mr.
Newport as highly deserving the distinction they have conferred
upon him by the award of the Royal Medal for Animal Physiology in
the present year.

The Council proj)ose to give one of the Royal Medals in the year
1839 to the most important unpublished paper in Astronomy com-
municated to the Royal Society for insertion in their Transactions
after the present date, and prior to the termination of the Sessions
in June 1839.

The Council propose to give one of the Royal Medals in the year
1839, to the most important unpublished paper in Physiology, com-
municated for insertion in their Transactions after the present date,
and prior to the termination of the Sessions in June 1839.

The ballot for Officers and Council being taken, the following was
the result :

President: His Royal Highness the Duke of Sussex, K.G. —
Treasurer: Francis Baily, Esq. — Secretaries: Peter Mark Roget,
M.D. ; John George Children, Esq. — Foreign Secretary: Charles
Konig, Esq,

Other Members of the Council : George Biddell Airy, Esq., A.R. j
William Allen, Esq. ; John Bostock, M.D. ; The Earl of Burlington;
Samuel Hunter Christie, Esq. ; Viscount Cole, M.P. j Joseph Henry
Green, Esq. ; George Bellas Greenough, Esq. j William Lawrence,

216^ Itoj/al Society.

Esq. J John Lindley, Phil. D, ; John William Luhbock, Esq., M.A. j
Rev. George Peacock, M.A. j William Hasledine Pepys, Esq. ; Rev.
Adam Sedgwick, M.A. 5 William Henry Smyth, Capt. R.N. ; Wil-
liam Henry Fox Talbot, Esq.

December 8, 1836. — A paper was read, entitled, *' Inquiries re-
specting the Constitution of Salts. Of Oxalates, Nitrates, Phos-
phates, Sulphates, and Chlorides." By Thomas Graham, Esq., F.R.S.
Edin., Professor of Chemistry in the Andersonian University of
Glasgow, Corresponding Member of the Royal Academy of Sciences
of Berlin, &c. Communicated by Richard Phillips, Esq., F.R.S.

The results which the author had obtained from his former expe-
riments, and of which he communicated an account to the Royal
Society*, suggested to him the probability that the law with re-
spect to water being a constituent of sulphates, would extend also
to any hydrated acid and the magnesian salt of that acid. As he
had already found that the sulphate of water is constituted like the
sulphate of magnesia, so he now finds the oxalate of water to re-
semble the oxalate of magnesia, and the nitrate of water to resem-
ble the nitrate of magnesia. His researches render it probable that
the correspondence between water and the magnesian class of oxides
extends beyond their character as bases; and that in certain subsalts
of the magnesian class of oxides, the metallic oxide replaces the
water of crystallization of the neutral salt, and discharges a func-
tion which was thought peculiar to water. In the formation of a
double sulphate, the author finds that a certain degree of substitu-
tion or displacement occurs ; such as the displacement of an a'ora
of water pertaining to the sulphate of magnesia, by an atom of sul-
phate of potash, to form the double sulphate of magnesia and pot-
ash. The same kind of displacement appears to occur, likewise, in
the construction of double oxalates ; and the application of this
principle enables us to understand the constitution both of the
double and super-oxalates, and to explain the mode of their deriva-
tion.

The author then proceeds to apply these principles to the analy-
sis of the oxalates; and 1st, of the oxalate of water, or hydrated
oxalic acid; 2ndly, of oxalate of zinc; 3rdly, of oxalate of magnesia;
4thly, of oxalate of lime; 5thly, of oxalate ofbarytes; 6thly, of
oxalate of potash; 7thly, of binoxalate of potash; 8thly, of quad-
roxalate of potash; 9thly, of oxalate of ammonia; lOthly, of oxalate
of soda; llthly, of binoxalate of soda; and lastly, of the double
oxalates, such as, 1st, oxalate of potash and copper ; 2ndly, oxalate
of chromium and potash ; 3rdly, oxalate of peroxide of iron and
potash ; and 4thly, of oxalate of peroxide of iron and soda.

In the second section he treats of the nitrates; and 1st, of hy-
drated nitric acid, or the nitrate of water ; 2ndly, of nitrate of cop-
per J 3rdly, of subnitrate of copper; 4thly, of nitrate and subnitrate
of bismuth J 5thly, of nitrate of zinc; 6thly, of nitrate of magnesia;
and 7thly, of supposed double nitrates and supernitrates. He con-

• See Lend, and Edinb. Phil Mag., vol. iii. p. 451.

Royal Society, 2 1 7

eludes, from his experiments on this subject, that there is no proof
of the existence of a single supernitrate.

In the third section he discusses the constitution of the phos-
phates. Phosphoric acid, he observes, is quite peculiar in being
capable of combining with bases in three different proportions ;
forming, besides the usual class of monobasic salts, containing one
atom of acid to one atom of protoxide as base, two other anormal
classes of salts, in which two or three atoms of base are united to
one atom of acid, namely, the pyrophosphates and the common
phosphates, as they are usually denominated, but which the author
proposes to designate by the terms, bibasic^ and tribasic phosphates.
Arsenic acid forms only one class of salts; but that class is anormal;
every member of it containing three atoms of base to one atom of
acid, like the common, or iribasic, phosphates. These anormal
classes of phosphates and arseniates, with, perhaps, the phosphites,
are, the author believes, the only known salts tq which the ordinary
idea of a subsalt is truly applicable: all other reputed subsalts be-
ing probably neutral in composition, as has been shown by the au-
thor in the case of the subnitrate of copper 5 for they all bear an
analogy to this salt in their small solubility and other properties,
while they exhibit little resemblance to those classes of phosphates
and arseniates which really possess more than one atom of base. A
table is then given, containing the formulae expressing the composi-
tion of the most important phosphates, together with a new nomen-
clature by which, in accordance with his views, the author proposes
to designate these salts. He then enters into the details of experi-
ments illustrating the composition of, 1st, tribasic phosphate of soda,
ammonia, and water, (or the microcosmic salt of the old chemists):
2ndly, tribasic phosphate of zinc and water, (or what is commonly
called phosphate of zinc^i: Srdly, tribasic arseniate of magnesia and
water, (the common arseniate of magnesia): 4thly, tribasic phosphate
of magnesia and watej-, (or ordinary phosphate of magnesia): and
5thly, tribasic phosphate of magnesia and ammonia, (or ammoniaco-
magnesian phosphate).

In the fourth section he treats of sulphates, and supports, by fur-
ther evidence, the ojjinion he formerly advanced; that as bisulphate
of potash is a double sulphate of water and potash, and therefore
neutral in its composition, so, with the sole exception of the anor-
mal class already noticed, all salts, usually considered as bisalts are,
in like manner, really neutral in composition. He shows that this
theory is strictly applicable to the red chromate of potash, which
appeared to present a difficulty.

The chlorides are next considered. The law followed by the
chlorides of the magnesian class of metals appears to be that they
have two atoms of water strongly attached to them, and which may
therefore be regarded as constitutional. Thus, chloride of copper
crystallizes with two atoms of water, and with no lower proportion;
but several chlorides of this class have two or four atoms more; the
proportion of water advancing by multiples of two atoms. The
chlorides have probably their analogues in the cyanides, although we
Third Series. Vol. 10. No. 60. March 1837. 2 F

^18 Boyal Society.

are less acquainted with the single cyanides of iron, copper, &c.:
but the disposition of the protocyanide of iron, and of the cyanide of
copper to combine with two atoms of cyanide of potassium, may de-
pend on the cyanides of iron and of copper possessing, like the cor-
responding chlorides, two atoms of constitutional water, which are
displaced by two atoms of the alkaline cyanide in the formation of
the double cyanides.

December 15, 1836. — A paper was read, entitled, " Further Ob-
servations on the Optical Phenomena of Crystals." By Henry Fox
Talbot, Esq., F.R.S.

The author had described, in a former paper*, the remarkable cir-
cular mode of crystallization frequently occurring from a solution
of borax in phosphoric acid, and producing, when examined by the
polarizing microscope, the appearance of a black cross, with four
sectors of light, and occasionally coloured rings, upon each crystal.
In the present memoir, he describes some deviations from the usual
forms of crystalline circles ; the most striking varieties consisting in
the cross being itself highly coloured, instead of black, upon a
white ground. The author shows that these crystals consist of bo-
racic acid alone, resulting from the decomposition of the borax by
the phosphoric acid. He gives an explanation of the optical ap-
pearances they present on the hypothesis of their being constituted
by an aggregate of acicular crystals, radiating from a central point,
and the whole circle being of variable thickness at different distances
from its centre, and acting with great energy on polarized light.
Other modes of crystalline formation, dependent chiefly on the pre-
sence or absence of combined water, are next described. These
sometimes produce crystals composed of two opposite sectors of a
circle, united at the centre j at other times, they exhibit irregular
elongated shapes, having a stem, either subdivided at both extremi-
ties into minute diverging fibres, or abruptly truncated ; and occa-
sionally they present regular geometric forms : but, whatever be
their shape, they undergo, in general, spontaneous changes in the
course of one or two days after they have been formed.

The author then notices a property belonging to some crystals,
similar to that possessed by the tourmaline, of analysing polarized
light ; for which reason he denominates them analytic crystals. As
an example, he mentions those obtained by dissolving sulphate of
chromium and potash in tartaric acid by the aid of heat. A drop
of this solution, placed on a plate of glass, soon yields, by evapora-
tion, filmy crystals, which frequently have this propert}^ The
plumose crystals of boracic acid, when crystallized from a solution
of borax in phosphoric acid, also possess this analytic power, and
present very beautiful appearances when viewed with the polarizing
microscope. Another instance occurs in the oxalate of potash and
chromium, a salt whose optical properties have been investigated by
Sir David Brewster. If gum arabic be added to a solution of this
salt, and a drop of it be put between two plates of glass, a very
beautiful arborescent, but microscopic crystallization takes place,
* See our last volume, p. 288.

Royal Society. 219

composing a multitude of minute prisms, growing, as if by a species
of vegetation, and variously arranged in sprigs and branchlets, often
resembling in miniature, the tufts of marine confervae. A similar
plumose appearance, accompanied with the same analytic proper-
ties, is obtained from the evaporation of a drop of a mixed solution
of nitre and gum arable. This analytic effect is shown to be the
consequence of the high degree of doubly refractive power pos-
sessed by these crystalline filaments, and which exists even in those
whose diameter is evanescent on microscopic examination. The
author entertains hopes that it will be possible to obtain large and
permanent artificial crystals, which may possess the advantages of the
tourmaline, without the inconvenience resulting from its dark colour.

December 22, 1836 — '* First Memoir on the Theory of Analy-
tical Operations." By the Rev. Robert Murphy, M.A., F.R.S.,
Fellow of Caius College, Cambridge.

The author considers the elements of which every distinct analy-
tical process is composed, as of three kinds; the first, being the 5m6-
jecty that is, the symbol on which a certain notified operation is to
be performed; the second, the operation itself, represented by its
own symbol; and the third, the result ^ which may be connected with
the former two by the algebraic symbol of equality. The operations
are either wowoww/ or polynomial', simple or compounds and with
respect to their order, are e\\\\QV fixed ox free. He uses the term
linear operations to denote those of which the action on any subject
is made up by the several actions on the parts, connected by the
signs plus or minus^ of which the subject is composed ; and these
linear operations likewise may be monomial or polynomial.

A variety of theorems for the development of functions of a very
general nature are then deduced from expansions of the fundamen-
tal expressions, derived from the principles stated in the beginning
of this memoir : and various laws embracing the relations subsisting
between analytical operations, and the fundamental formulae for their
transformation are investigated.

*' Observations and Experiments on the Solar Rays that occasion
Heat ; with the application of a remarkable property of these rays
to the construction of the Solar and Oxy-hydrogen Gas Micro-
scopes." By the Rev. J. B. Reade. Communicated by J. G. ChiU
dren, Esq., Sec. R.S.*

The method employed by the author for obtaining, by a com-
bination of lenses, the convergence to foci of the colorific solar rays,
together with the dispersion of the calorific rays, consists in making
a beam of solar light, which contains both kinds of rays, pass, after
it has been converged to a focus by a convex condensing lens,
through a second convex lens, placed at a certain distance beyond
that focus: that distance being so adjusted as that the calorific rays,
which, from their smaller refi'angibility, are collected into a focus
more remote from the first lens than the colorific rays, and conse-
quently nearer to the second lens, shall, on emerging from the
latter, be either parallel or divergent j while the colorific rays, which,

* See our present Number, p. 184.
2 F2

220 Roi/al Society,

being more refrangible, had been collected into a focus nearer to the
first lens, and more distant from the second, will be rendered con-
vergent by this second lens; so that the second focus, into which
they are thus collected, will exhibit a brilliant light without mani-
festing any sensible degree of heat. The light so obtained may be
advantageously applied to the solar, and to the oxy-hydrogen mi-
croscopes, from its producing no injurious effects on objects inclosed
in Canada balsam, or even on living animalcules exposed to its in-
fluence.

Another improvement in the construction of the microscope em-
ployed by the author, consists in the cell for holding objects being
made to move quite independently of the field glass ; so that the
best focus is obtained by an adjustment which does not disturb the
field of view.

January 12, 1837. — "An attempt to account for the discrepancy
between the actual Velocity of Sound in Air or Vapour, and that
resulting from theory." By the Rev. William Ritchie, LL.D.,
F.R.S. Professor of Natural Philosophy at the Royal Institution,
and in University College, London.

Sir Isaac Newton determined from theory that the velocity of the
undulations of an elastic medium generally is equal to that which a
heavy body acquires in falling by the action of gravity through half
the height of a homogeneous atmosphere of that medium; but the
actual velocity of sound in atmospheric air is found to be one eighth
greater than what is assigned by that formula. This difference was
attempted to be accounted for by Newton on the supposition that
the molecules of air are solid spheres, and that sound is transmitted
through them i?istanter. Laplace endeavoured to reconcile the
difference between theory and observation, by the hypothesis that
heat is disengaged from each successive portion of air during the
progress of the condensed wave. The author of the present paper
regards the hypothesis of Laplace as a gratuitous and improbable
assumption ; the falsehood of which he thinks is apparent from the
fact that a rarefied wave advances through air with the same velocity
as a condensed wave, which would not be the case if in either instance
their progress were influenced by the heat evolved. He then enters
into calculations to show that if the molecules of water be assumed
as incompressible, and, when at the temperature of maximum den-
sity, very nearly in absolute contact, we ought, in estimating the
velocity of sound in steam, to add to the velocity given by the for-
mula of Newton, the rectilinear space occupied by the molecules ;
which, if a cubic inch of water be converted into a cubic foot of
steam, will be one twelfth of the distance. By comparative expe-
riments with a tuning-fork held over a tube, closed at one end, and
containing at one time air, and at another steam, and also by simi-
lar trials with organ pipes of variable lengths, the author found a
close agreement between his theory and observation. He also shows
that this theory furnishes the means of determining, a priori, the
density of a liquid, if the velocity of sound in the vapour of that
liquid be given. In a postscript he adduces further confirmation of

Royal Society, 221

tlie truth of his theory by observations on the velocity of sound n
hydrogen gas, and in carbonic acid gas.

January 19. — " Researches towards establishing a Theory of the
Dispersion of Light." By the Rev. Baden Powell, MA., F.R.S.,
Savilian Professor of Geometry in the University of Oxford.

The author here prosecutes the inquiry on the dispersion of light
which was the subject of his former papers published in the Philo-
sophical Transactions for 1835 and l83(», extending it to media of
higher dispersive powers, which afford aseverer test of the accuracy
of M. Cauchy's theory. He explains his methods of calcula-
tion and the formulae on which his computations are founded, and
which are different from those employed in his former investigations :
and then states the results in a tabular form. On the whole he con-
cludes that the*, formula, as already deduced from the undulatory
theory, applies sufficiently well to the case of media whose disper-
sion is as high as that of oil of anise-seed \ or below it, such as
nitric, muriatic, and sulphuric acids, and the essential oils of angelica,
cinnamon, and sassafras, balsam of Peru, and kreosote. It also re-
presents, with a certain general approximation to the truth, the in-
dices of some more highly dispersive bodies. The author therefore
considers it as extremely probable that the essential principle of
the theory has some real foundation in nature. From the regularity
which he finds in the deviation of observation from theory, he thinks
it likely that the formula only requires to receive some further de-
velopment, or extension, in order to make it apply accurately to
the higher cases, while it shall still include the simpler form which
so well accords with the lower.

" A few remarks on the Helm Wind." By the Rev. William Wal-
ton, of Allenheads, near Hexham. Communicated by P. M. Roget,
M.D., Sec. R.S.

On the western declivity of a range of mountains, extending from
Brampton, in Cumberland, to Brough, in Westmoreland, a distance
of 40 miles, a remarkably violent wind occasionally prevails, blow-
ing with tremendous violence down the western slope of the moun-
tain, extending two or three miles over the plain at the base, often
overturning horses with carriages, and producing much damage,
especially during the period when ripe corn is standing. It is ac-
companied by a loud noise, like the roaring of distant thunder; and
is carefully avoided by travellers in that district, as being fraught
with considerable dajiger. It is termed the helm luind ; and its
presence is indicated by a belt of clouds, denominated the helm bar,
which rests in front of the mountain, three or four miles west of its
summit, and apparently at an equal elevation, remaining immove-
able during twenty-four or even thirty-six hours, and collecting or
attracting to itself all the light clouds which approach it. As long as
this bar continues unbroken, the wind blows with unceasing fury, not
in gusts, like other storms, but with continued pressure. This wind
extends only as far as the spot where the bar is vertical, or imme-
diately overhead; while at the distance of a mile further west, as
well as to the east of the summit of the mountain, it is not unfre-

222 Royal Society.

quently almost a perfect calm. The author details the particulars
of an expedition which he made with a view to investigate the cir-
cumstances of this remarkable meteorological phenomenon, and
proposes a theory for its explanation.

"A Meteorological Journal kept at Allenheads, 1400 feet above
the level of the ISea, from the Ist of May to the 1st of November,
1836." By the Rev. William Walton. Communicated by P. M. llo-
get, M.D., Sec. U.S.

January 26. — A paper was read, <* On the Structure of the Brain
in Marsupial Animals." By Richard Owen, Esq., F.R.S., Hunterian
Professor of Anatomy to the Royal College of Surgeons.

The author describes a remarkable modification in the commis-
sural apparatus, apparently provided with a view to establish com-
munications between the cerebral hemispheres, which he has ob-
served in the brains of marsupial animals, and which has hitherto
been regarded as constituting the essential difference between the
brains of oviparous and mammiferous vertebrata, but which he con-
siders as indicating a certain relation between the greater perfection
of that organ, resulting from the superior magnitude of the great
commissure, or corpus callosum, and the placental mode of deve-
lopment in the true mammalia. In a former paper he adduced evi-
dence tending to show that both a small development of the cere-
bral organ, and an inferiority of intelligence are the circumstances
in the habits and structure of this singular tribe of animals most con-
stantly associated with the peculiarities of their generative economy:
and the repeated dissections he has since made, an account of which
is given in the present paper, have afforded him the most satisfactory
confirmation of this coincidence, between a brief intra-uterine ex-
istence, together with the absence of a placental connexion between
the mother and the foetus, and an inferior degree of cerebral de-
velopment. Thus, on comparing the structure of the brain in the
Beaver and in the Wombat, he finds that the corpus callosum, or
great commissure which unites the supraventricular masses of the
hemispheres in the former, as well as in all other placentally deve-
loped mammalia, and which exists in addition to the fornix, or
hippocampal commissure, is wholly absent in the latter animal :
and that a similar deficiency exists in the brain of the Great and
Bush Kangaroos, of the Vulpine Phalanger, of the Ursine and
Mange's Dasyurus, and of the Virginian Opossum ; whence he
infers that it is probably the characteristic feature of the structure
of the marsupial division of mammalia. In this modification of the
commissural apparatus, the Marsupiata present a structure of brain
which is intermediate between that of the Placental Mammalia and
Birds ; and hence the Marsupiata, together with the Monotremata,
may be regarded as constituting a distinct and peculiar group in the
former of these classes, although they include forms, which typify
the different orders of the ordinary Mammalia.

Linncean Society, 22$

LINN^AN SOCIETY.

Dec. 20, 1836. — A paper was read, entitled "Descriptions of the
Species of Polygonum and Fagopyrum contained in the Indian Her-
barium of Professor Royle, F.L.S., Sec. Geol. Soc. By Charles
C. Babington, Esq., M A., F.L.S.

Professor Royle's collections were chiefly formed in Sir more, Ku-
nawar, and Cashmere, and comprise a considerable number of new
species, besides many that are identical with those found by Dr.
Wallich in Nepal. The most interesting additions to the present
genus consist of five species of the section Avicularia. We sub-
join an enumeration of the species, together with characters of the
new ones.

Polygonum, Linn,
Sect. 1. Bistorta, Meisn.

1. P. bulbiferum.

Spic^ compacta densa basi interrupt^ laxiuscula, bracteis ovatis
acuminatis subincisis, staminibus calyce brevioribus filamentis
post anthesin elongatis, stylis 2 rarius 3 calyce duplo longioribus,
achenio calycis longitudine lenticular! faciebus rotundato-acumi-
natis minute granulato-striatis subopacis, foliis caulinis subsessilibus
lanceolatis radicalibus petiolatis ellipticis vel elliptico-lanceolatis
omnibus in margine revoluto costato-crenatis.

P. bulbiferum, Royle MSS.

2. P. macrophyllum, Don.

3. P. amplexicaule, Don.

4. P. vaccinifolium, Meisn.

5. P. affine, Don.

6. P. Emodi, Meisn.

Sect. 2. Amblygonon, Meisn.

7. P. orientale, Linn.

Sect. 3. Persicaria, Meisn.

8. P. lanigerum, R. Br. I 10. P. barbatum, Lin?i,

9. P. hispidum, Don. \ 11. P. scabrinervium.

Spicis pedunculatis geminatis subcymosis strictis laxis pedunculis
longioribus, bracteis acutis eglandulosis glabris 3 — 'i-floris pedi-
cellis subaequalibus, floribus 6-andris semidigynis, calyce 4-fido
eglanduloso, staminibus inclusis, achenio lenticulari laevi nitido,
pedunculis glandulosis, ochreis glabris non ciliatis, foliis lanceo-
latis glandulis flavis numerosissimis supra et subtiis notatis glabris
margine costaque scabroso-pilosis, cauW erecto ramoso in superior!
parte glanduloso.

P. scabrinervium, Royle MSS,

12. P. simlense.

Spicis paniculatis pedunculatis ovato-oblongis multifloris, pedun-
culis glandulosis, bracteis turbinato infundibuliformibus parvis 2 — 3-
floris pedicellis aequalibus, floribus 4-fidis, 6-andris semi-2-gynis,
achenii lenticulari calyce absconditi faciebus planis nitidis minu-
tissime granulatis, ochreis cylindricis muticis glabris, foliis lanceo-
latis glabris costa setoso-scabru excepta, margine scabro-ciliatis,

22+ Lhinccaji Society,

caule erecto subsimplici fistuloso glabro in superiori parte glandu
loso.

P. simlense, Royle MSS.

13. P. glabrum, Willd. \ 14. P. Donii, Me/^n.

Sect. 4. Cephalophilon, Meisn.
Subsect. 1. Didymoceplialon, Meisn

15.P. filicaulcW^fl//.

16, P. punctatum, Don.

17. I*, nepalense, Meisn,

18. P. sphaerocephalum, Wall.

19. P. capitatum, 7)ow.
^O.P. sinuatLim.

Capitulis solitariis, pedunculis glabris, bracteis ovatis obtusis,
floribus 5-andris semitrigynis laciniis obtusis, achenio triquetro,
ocbreis glabris vel parce pilosis, foliis lyratis lobo terminali rhom-
boideo, petiolo basi biauriculato, caule ramose.

P.siniiatiwi, Iloyle MSS.

Subsect. 2. Corymbocephalon, Meisn,

21. P. chinense, Linn,

Sect. 5. Aconogonon, Meisn.

22. P. tortuosum, Don, \ 23. P. Hagei.

Paniculi ramis subsimplicibus aphyllis, bracteis 3 - 6-floris pedi-
cellos erectos subaequantibus, calycis laciniis rotundato-ovalibus
obtusis glabris 2 exterioribus angustioribus, ochreis petiolo lon-
gioribus internodio brevioiibus, foliis lanceolatis apice lineari-
attenuatis subtijs lanato-velutinis supra pubescentibus, caule erecto
ramoso striato cum ramis pedunculis ochreisque pilosis,

P, Hagei, Uoyle MSS.

24. P. polystachyum, Wall, \ 25. P. rumicifolium.

Paniculis subsimplicibus, bracteis basi pilosis unifloris pedicellis
brevioribus, calycis laciniis obovatis obtusis aequalibus, ochreis in-
ternodio dimidio brevioribus petiolo longioribus pilosis, foliis cor-
datis ovatisve pilosis, margine undulato, caule erecto striato.

P. rumicifolium y Royle MSS.

Sect. 6. Tinaria, Meisn,
26. P. Convolvulus, Linn. \ 27. P. heterocarpum, Wall.

Sect. 7. Avicularia, Meisn.

28. P. herniarioides, Delile. I 30. P. Royle .

29. P. aviculare, Linn. ? j

Floribus axillaribus parvis pedicello brevissimo, achenio trigone
granulato-striato perigonio aequali, ochreis acutis lobatis haud
laceris : venis 2 obsoletis, foliis linearidanceolatis acutis integris
punctis glandulosis numerosissimis, caule 3 — 4 angulato, angulis
scabris.

31. P. mucronatum.

Floribus axillaribus parvis sessilibus,acbenio trigone laevi, ochreis
ovatis acutis laceris internodiis longioribus nervis nullis, foliis lanceo-

Linncean Society. 225

lato-linearibus longe mucronatis marginibus recurvisi caule pubes-
centi lignoso.

P. mucronatunif Royle MSS.

32. P. recumbens.

Floribus axillaribus parvis pedicello brevi, achenio trigone laevi
nitido angulis rotundatis segmentis caiinatis perigonii claubi tecto,
ochreis lanceolatis acutis deruum laceris : nervis 2 excurrentibus
foliis ovatis brevi-petiolatis margine nervisque subtiis scabris.

P. recumbens f Royle MSS.

33. P. confertum.

Floribus axillaribus parvis globosis, pedicello brevi, achenio com-
presso trigonove laevi nitido segmentis non-carinacis perigonii cam-
panulati tecto,ochreis lanceolatis acutis demum laceris : nervis abbre;
viatis foliis oblongis 1-nervosis brevi-petiolatis margine nervoque
subtiis scabris. ,■

P. confertum, Royle MSS.

Fagopyrum, Gcertn.

1. F. rotundatum.

Floribus parvis paniculato-racemosis, achenio trigono angulis
rotundatis in superiori parte carinatis calyce 4< — 5-pld longiore fa-
ciebus oblongo-ovatis rugosis, foliis triangulari-hastatis paulo lon-
gioribus quam latis petiolatis, caule erecto annuo.

2. F. esculentum, Mcench, \ 3. F. emarginatum.
Floribus paniculatis parvis pedicello elongato, achenio trigono

angulis alatis integris calyce obtuso duplo longiore faciebus ovatis
longioribus quam latis, foliis petiolatis triangularibus acutis, angulis
inferioribus rotundatis.
P, emarginatum^ Roth? Cat. Bot. I. 48. Don? Prod. 73. Meisn.?

Mon. 62.

^, F. cymosum^ Meisn.

Jan. 17, 1837. — Read the commencement of a paper by John
O. Westwood, Esq., F.L.S., entitled '* Illustrations of the Relation-
ships existing amongst natural Objects termed Affinity and Analogy,
selected from the class of Insects."

Feb. 7. — Read a notice, accompanied by specimens, of the dis-
covery of Polygonum dumetorum and Epipactis purpurata in the
vicinity of Reigate, Surrey. By Mr. George Luxford, A.L.S.

The chief distinctions of Polygonum dumetorum consist in its per-
fectly cylindrical stem, elongated pedicels, and smooth and shining
fruit. The P. Convolvulus varies in the breadth of the margins of
its sepals, and in some states it equals that of the former species.
The racemes and pedicels in the latter are always much shorter,
the stems angular, and the fruit opake, and beset with minute
elevated dots.

The Epipactis purpurata, first described in the fourth volume of
the " English Flora," appears to be only a variety of E. latifolia.

Specimens of a remarkable variety of Pinus Pumiiio, having the
scales of the cones singularly lengthened and reflexed, were exhi-

Third Scries. Vol. 10. No. 60. March 1837. 2 G

226 Linncean Society,

bited from the extensive collection of His Grace the Duke of Bed-
ford at Woburn Abbey.

Mr. Lambert, V.P., exhibited specimens of the Tamarix ma7inifera,
a species nearly related to T.gallica, and of tlie sweet gummy sub-
stance which exudes from the wounds occasioned by a species of
CoccHSy said by Ehrenberg and Hemprich to be peculiar to the
valley at the foot of Mount Sinai, where the substance is collected,
which is called " Man" by the Arabs, and supposed to be identical
with the manna recorded in Scripture. The specimens were col-
lected by Lieutenant Wellsted.

Read a continuation of Mr. Westwood's paper on Affinity and
Analogy.

Feb. 21. — Head, Some Observations on the Manna of Mount Sinai,
and the Dragon's Blood Tree and Aloe Plant of Socotra. By Lieut.
Wellsted.

It is in Wady Hebron that the Manna is obtained by the Bedouins,
who collect it early in the morning, and after straining it through
cloths they put it into skins or gourds. The quantity collected
in the most favourable seasons does not exceed 700, pounds. A
considerable quantity is consumed by the Bedouins themselves, but
a portion is sent to Cairo, and some is disposed of to the monks of
the convent at Mount Sinai, who retail it to the Russian pilgrims,
by whom it is received with much reverence as an incontestible proof
of the truth of the event recorded in Scripture. The substance is
only collected in seasons after heavy rains, for it has been known to
be wanting for a period of seven years. When recent it has the
consistence and flavour of honey, and is of a deep amber colour.

The Dragon's Blood Tree of Socotra appears to be identical with
that of the Canary Islands, which is the Draccena Draco of Linnaeus.
In Socotra it is rarely met with below the altitude of 800 feet, and
it is frequently seen growing on the granite peaks at an elevation of
4000 or 5000 feet above the level of the sea. The gum exudes spon-
taneously, or from artificial incisions in the trunk. The season most
favourable for obtaining it is in June, immediately after the setting of
the S.W. monsoon.

The island of Socotra has been famous from the earliest period
for its Aloes ; but that article of export has of late years fallen into
neglect, so that not more than two tons were exported in 1833.
The plant abounds all over the island, and is most probably identi-
cal with the Aloe officinalis of Forskal, FL ^gypt. Arab. cent. 3. p. 73.
The leaves are short and stained with a reddish-brown colour, and
the flowers are red. The species belongs to the same group of
the genus with the Aloe vulgaris.

Mr. IlifF, F.L.S., exhibited a portion of the trunk of an oak
which was blown down in Windsor Park during the late hurri-
cane, which upon being split was found to contain the letters
W. B. and the year 1670 carved on it.

Read, the commencement of a paper by Joseph Woods, Esq.,
F.L.S., entitled <' Observations on the European Genera of Grasses."

Royal Astronomical Society. 227

ROYAL ASTRONOMICAL SOCIETY.

Nov. 11, 1836. — The following communications were read : —

I. Extract from a Letter from Mr. Maclear to Captain Beaufort,
accompanied by the original Circle and Transit Observations of
Halley's Comet since January.

The number of meridian observations thus obtained is upwards
of thirty. The reductions will be forwarded in a short time j the
delay arising from Mr. Maclear being employed in observing the
stars of the Brisbane list, in aid of Sir John Herschel, who, he states,
is now occupied in reducing his Catalogue of Southern Nebulae.

II. A Catalogue of the Right Ascensions of 1318 Stars, observed
at Blackheath. By Mr. Wrottesley.

These papers consist of a catalogue in Right Ascension of 1831
stars (those of the 6th and 7th magnitude inclusive, contained in
the Astronomical Society's Catalogue), with an explanatory intro-
duction and notes ; and also of the original observations, and the
reduced mean places, from which the catalogue is formed. As this
is the first contribution by a private observer to a more accurate
knowledge of the places of the fixed stars, which has been made in
consequence of the Society's Catalogue, and according to its direc-
tions; and as the deductions are of great value and importance ; a
distinct report has been made by a Committee, and adopted by the
Council, in order that due credit may be given to the labours of
Mr. Wrottesley and of his assistant Mr. Hartnup.

The observations were made with a transit telescope, by Mr.
Thomas Jones, of 3J inches clear aperture, 62 inches focal length,
and 27 inches horizontal axis. The power used was 142. The
position of the instrument was ascertained, when practicable, by-
consecutive transits of Polaris above and below pole : and in other
circumstances, by single transits of Polaris or 3 Ursae Minoris. This
was checked, in some degree, by a close mark seen through a fixed
lens; which, however, discharged a better purpose in determining
the error of coUimation whenever the instrument was reversed.
This was done every month. The level was always applied (of
course in reversed positions) once every night, and often twice, viz.
at the beginning and end of a series of observations. At first, cor-
rections for the instrumental errors were computed and applied,
but the amount was found to be so small, that Mr. Wrottesley sub-
sequently preferred taking the clock error for the stars of his cata-
logue from the standard or standards, which, having nearly the
same declination, were affected by the same instrumental errors.
Thus the instrumental errors, which were always noted and kept
low, were, as to sense, eliminated.

The bases of this catalogue are, the fundamental catalogue of
Bessel for the mean places of the standard stars (omitting some not
suited to Mr. Wrottesley's purposes, and substituting his own place
of Fomaihaut for the erroneous place of Bessel ; ) and for the correc-
tions, the constants and precessions of the Astronomical Society's ca-
talogue, and the ralues of A, B, C, D, contained in the Nautical AU

2G2

228 Boyal Astronomical Society.

manac. The number of observations of the stars in the catalogue is
12007, or rather more than 9 observations for each star, on an average.

The partial mean places appear to be as close to each other, or
nearly so, as those of the Greenwich observations. It follows, from
Mr. Wrottesley's method of deducing the clock error for each star
from one, two, or more standards which are near it, that the acci-
dental errors are greater than he would have had, if he had used all
the standard stars for his clock error ; but, as it is, a greatest differ-
ence from the mean of ten or twelve observations exceeding O'^'S
is not common, which leaves only a small uncertainty upon the
final result; especially since this difference, being the sum of two
independent errors of observation, viz. that of the standard deter-
mining star and that of the catalogue star, may be expected to have
little effect in the mean of several observations. Indeed, there
can be no doubt, that this catalogue of Mr. Wrottesley's may be
used for all purposes, with nearly, if not altogether, the same con-
fidence as the fundamental catalogue from which it is derived.

Of the means taken to insure accuracy in the reductions, Mr.
Wrottesley has given a very satisfactory account, and that these
means have been effectual, he has stated the following proof. In
Mr. Wrottesley's catalogue are 138 stars observed and reduced by
Professor Airy in the Cambridge observations. *' Of these, 46 agree
within 0'-05; 89 within 0^-10; 115 within 0«-15 j 131 within 0-20;
and only one differs so much as 0'*30." We have a further and in-
dependent proof of the correctness of this catalogue in the Re-
marks (appended by Mr. Baily) on the differences of I'-O and up-
wards, between the catalogue of Mr. Wrottesley and that of the
Astronomical Society. It is known to the Society, that our cata-
logue has been pretty nearly reobserved by Mr. Taylor at Madras,
and very well observed, though, unfortunately,very few copies [of Mr.
Taylor's catalogue] have found their way into the hands of English
astronomers. There are 29 stars having such differences, of which
24- have been observed by Mr. Taylor, and in every instance his result
confirms that of Mr. Wrottesley. Whether these anomalies are to be
attributed to errors in the catalogues of Bradley or Piazzi (for Mr.
Baily has examined the computations by which our catalogue is de-
duced from theirs), or whether there is some irregular motion in the
stars themselves, time will show. It is from such undertakings as this
of Mr. Wrottesley, and so executed, that we must expect to fix the
state of the heavens at certain epochs, and so prepare the data for
future speculation and future discovery. For such inquiries, Mr.
Wrottesley's present of the original transit books, to which the
partial mean places serve as a complete index, will be of great and
permanent value.

There are several remarks which deserve, and doubtless will re-
ceive, the attention of practical astronomers, but which would be
here out of place. We must not, however, omit mentioning that
the whole work has been performed, to use Mr. Wrottesley's words,
" without any foreign aid," by himself, and, under his superintend-
ence, by his assistant Mr. John Hartnup; upon whom, indeed, in

Royal Astronomical Society. 229

consequence of Mr. Wrottesley's frequent and continued absence
from home, the task of observing and computing chiefly fell, and
who has executed this task with extraordinary zeal, skill, and fi-
delity.

J 1 1. On the Projection of Maps and Charts. By Professor Littrow.

Three kinds of projections are chiefly had recourse to in the
construction of maps, — the orthographic, the stereographic, and
tlie central. The object of Professor Littrow is to deduce the ge-
neral properties of these three principal projections, which, though
they differ from each other in no other respect than in the situation
of the eye and perspective plane, with regard to the principal circles
of the sphere, have hitherto been always treated as distinct and in-
dependent problems.

The concluding part of the memoir contains some general re-
marks on the solutions of the general problem by Gauss and La-
grange ; and a demonstration that Gauss's formulae (contained in a
memoir a translation of which appeared in Phil. Mag. and Annals,
N.S., for August and September 1828,) are comprehended in those
of Lagrange, the latter being only particular values of the former.

IV. On the construction of the Hour-lines of Sun Dials. By
Professor Littrow.

V. On the Formulae for the computation of Precession. By
M. Mattheus Valento do Conto, Director of the Observatory at
Lisbon.

VL Notice of a forthcoming work on the Measures of Double
Stars. By Professor Struve.

Professor Struve hoped, in June last, to complete his extended
catalogue of double stars, containing all the observations made since
those already published in his well-known Catalogus Stellarum
Duplicium, Dorpat, 1827 (or from 1824 to 1836). This last-men-
tioned catalogue contained 3112 stars; from which the professor
has, for various reasons assigned, excluded ^QO, and has added 64
remarkable new ones of greater distance than 32", and 21 of less
distance. The number of stars, therefore, is 2707. The measures
were made with a wire- micrometer applied to the large refractor,
with a power varying from 320 to 1000, and mostly in an illuminated
field. Calling each night's observations of one star a measure, the
number of measures is about 11,000, or, on an average, four to each
star.

Professor Struve has divided these stars into eight classes (Sir
W. Herschel used four), as follows :
W. 1
I. 0'' to 4'

n. 4 ^ 8

III. 8—16

IV. 16 — 32 —

'erschel.

Struve.

of distance.

I. 0" to 1"

of distance

II. 1 --^ 2

III. 2 — 4

IV. 4 — 8
V. 8—12

VI. 12 —16

Vn.l6 —24

Vin.24 —32

230 Royal Astronomical Socze/y,

Each class is further divided into two divisions, lucida and reliquee;
the former containing those in which the companion is not of less
than the eighth magnitude. The principle of this division is. Pro-
fessor Struve states, that the catalogue is very nearly complete
with respect to the lucidce, on which, therefore, certain theoretical
conjectures may be formed, relative to the numbers of double stars
in different orders of magnitude. The introduction, besides all the
matters explanatory of the present and emendatory of the former,
catalogue, which might certainly have been looked for from Pro-
fessor Struve, will contain conclusions concerning the nature of
double stars, from their distribution among the orders of magnitude,
their brightness, proper and relative motions, &c. Professor Struve
has added a specimen of the catalogue, and several interesting con-
clusions, of which our limits will only enable us here to notice the
very rapid motion of 42 Comae Berenices (130° in six years), the re-
duction of the period of \ Ophiuchi to less than 40 years, and the
close approach to their nearest distance of y Coronse and lo Leonis.
The latter system, between Sir William Herschel and Professor
Struve, has now been watched from the greatest to the least apparent
distance.

VII. Stars observed with the moon at the Royal Observatories
of Greenwich and Edinburgh, and the Observatory of Cambridge,
in the months of June— October, 1836.

Dec. 9, 1836. — The following communications were read, viz.: —

I. On a remarkable phaenomenon that occurs in total and an-
nular eclipses of the sun. By Mr. Baily, Vice-President of the
Society.

The' author states, that, having read of certain singular appear-
ances that are recorded as having taken place in annular eclipses
of the sun, at the moment that the whole disc of the moon enters
on the disc of the sun, he w^as desirous of witnessing those phseno-
mena at the solar eclipse of May 15th last j and, finding that the
central path of the moon's shadow would pass nearly in a straight
line from Ayr, on the western coast of Scotland, to Alnwick on the
eastern coast of Northumberland, he proceeded to Scotland for
that express purpose. Having computed, from the elements given
in the Nautical Almanac, that the central line of the moon's umbra
would pass directly over, or very near to, Jedburgh in Roxburgh-
shire ; and having ascertained that this place was within eight or
ten miles of Makerston, the seat of Lieut. -General Sir Thomas
Macdougal Brisbane, Bart., who has a well-furnished observatory
there, and from whom he was sure of obtaining the correct time for
his chronometers, he resolved to make that town his head-quarters.
Mr. Baily took with him a 34^-feet refracting telescope by Dollond,
2^ inches aperture, and magnifying about 40 times; a 20-inch
Rochon's prismatic telescope, for measuring the distances between
the borders of the sun and moon ; two thermometers j a burning-
glass ; and four pocket chronometers.

Mr. Baily took up his station at the house of Mr. Veitch, a very
ingenious gentleman, residing at Inch Bonney, about half-a-mile to

Royal Antronomical Society, 231

the southward of the town of Jedburgh, who afforded him every fa-
cihty for making the observations. The morning of the 15th of May
is described as being remarkably fine and clear ; not a cloud to be
seen in any part of the heavens during the whole time of tiie eclipse.
The times of the beginning and ending of the eclipse, and of the
fortnation and dissolution of the annulus, have already been given
in the third volume of the monthly abstracts of the Society's pro-
ceedings, page 200. But Mr. Baily does not lay much stress on this
part of his observations — more especially those connected with the
annulus — since his attention was taken up with other more interest-
ing phaenomena. He says he was in expectation of meeting with
something extraordinary at the formation of the annulus; but ima-
gined that it would be only momentary, and consequently, that it
would not interrupt the noting of the time of its occurrence. In
this, however, he was deceived, as the following facts will show.
For when the cusps of the sun were about 4^° asunder, a row of
lucid points, like a string of beads, irregular in size and distance
from each other, suddenly formed round that part of the circum-
ference of the moon that was about to enter on the sun's disc. This
he intended to note as the correct time of the formation of the an-
nulus, expecting every moment to see the thread of light completed
round the moon ; and attributing this serrated appearance of the
moon's limb (as others had done before him) to the lunar moun-
tains ; although the remaining portion of the moon's circumference
was perfectly smooth and circular, as seen through his telescope.
He was somewhat surprised, however, to find that these luminous
points, as well as the dark intervening spaces, increased in magni-
tude; some of the contiguous ones appearing to run into each other
like drops of water. Finally, as the moon pursued her course, these
dark intervening spaces were stretched out into long, black, thick,
parallel lines, joining the limbs of the sun and moon : when all at
once they suddenly gave way, and left the circumferences of the
sun and moon in those points, as in all the rest, apparently smooth
and circular, and the moon perceptibly advanced on the face of the
sun. This moment of time Mr. Baily considers to be that which
most persons would assume and record as the formation of the
annulus; but he adduces strong reasons afterwards to show that
the true formation of the annulus was some seconds prior to that
event.

After the formation of the annulus, as thus described, the moon
preserved her circular outline during its progress across the sun's
disc, till her opposite limb again approached the border of the sun,
and the annulus was about to be dissolved. When, all at once (the
limb of the moon being at some distance from the edge of the sun),
a number of long, black, thick, parallel lines, exactly similar in ap-
pearance to the former ones above mentioned, suddenly darted for -
•vaardy and joined the two limbs as before 3 and the same phaenomena
were repeated, but in an inverse order. For, as those dark lines
got shorter, the intervening bright parts assumed a more circular
shape, and at length terminated in a fine, curved line of bright

2S2 Royal Agronomical Society*

beids (as at the commencement), till they ultimately vanished, and
the annulus consequently became wholly dissolved. This remark-
able and singular phaenoraenon was also observed by Mr. Veitch,
and by Sir Thomas Brisbane, as well as by Mr. Henderson at
Edinburgh; with some slight differences, however, in the detail.
The appearance of the dark lines, or threads, was likewise noticed
by Mr. Bell, at Alnwick, who sent an account of the same to the
Philosophical and Literary Society at Newcastle. Mr. Baily de-
scribes them to have been as plain, as distinct, and as well defined,
as the open fingers of the human hand held up to the light ; and
that there could not have been any doubt as to their form and ex-
istence, since they were seen by different observers, at different
places, and with different telescopes. Several drawings accom-
panied the paper, showing the appearances at various stages of the
annulus.

The number of these dark lines, or threads, Mr. Baily considers
to have been about eight : in which opinion he was confirmed by
Mr. Veitch. Sir Thomas Brisbane, however, thinks there were not
more than six ; whilst Mr. Bell, who noticed four at the dissolution
of the annulus, says that there were only two at its formation. On
these and other points Mr. Baily thinks there is ample room for a
diversity of opinion, since the observer is taken, as it were, by sur-
prise, and the phaenomenon itself, during the short period of its ex-
istence, is constantly varying in some minute particulars.

Mr. Baily remarks, that the diminution of light was not so great
during the existence of the annulus as was generally expected,
being little more than might be caused by a temporary cloud pass-
ing over the sun : the light, however, was of a peculiar kind, some-
what resembling that produced by the sun shining through a morn-
ing mist. The thermometer in the shade fell only about three or
four degrees. The birds in the hedges were in full song during the
whole time of the eclipse. About twenty minutes before the forma-
tion of the annulus, Venus was seen with the naked eye ; and a few
minutes afterwards it was impossible to fire gunpowder, with the
concentrated rays of the sun, through a lens of three inches in dia-
meter. The same lens, likewise, had no effect on the ball of a ther-
mometer during the existence of the annulus.

For the cause of the remarkable optical deception above described,
Mr. Baily does not attempt to account ; but he confesses his sur-
prise that the phaenomenon has not (with one single exception,
which will be presently alluded to) been noticed or recorded, on
former occasions, since it must have been seen by every person who
watched for the formation and dissolution of the annulus; and al-
though detached portions of the phaenomenon have been recorded
by different observers, as seen at different places (various extracts
from whose accounts are quoted by Mr. Baily), yet it is impossible
from those descriptions to form an accurate idea of the whole, or to
trace the origin, progress, and termination of this phaenomenon,
which is certainly one of the most remarkable in astronomy. M.
Van Swinden is the only person who has placed on record the ob-

Roijal Astronomical Society. 233

servation of the dark lines, or threads, which connect the borders
of the sun and moon, at the formation and dissolution of the annu-
lus. His account is inserted in the first volume of the Memoirs of
this Society (page 146), accompanied with drawings, which coincide
almost exactly with those given by Mr. Baily. In nearly all the
accounts by other observers, the description of the phaenomenon
is restricted to the very commencement of the annulus, or to the
formation of the string of luminous points which on a sudden are
seen to surround that portion of the moon's limb about to enter on
the sun's disc; and no notice whatever is taken of the continuation
of the phuenomenon, or of the stretching out of the dark spaces
into parallel lines, as above mentioned : nor of their sudden rupture
and disappearance, which is by Air the most remarkable part of the
phaenomenon.

How far any of these appearances may favour the hypothesis of
a lunar atmosphere, or whether, indeed, they^could be accounted
for on such an assumption, the author does not stop to discuss ;
but, with a view to assist those who are disposed to enter on such
an inquiry, he has adduced various accounts of a similar phaeno-
menon to that of the dark lines, observed at the transits of Venus
over the sun in 1761 and 1769, For on each of those occasions,
many astronomers remarked, thtit, at the interior contact of Venus
with the sun (both on its ingress and egress), there was formed a
sort of dark ligament between the border of Venus and the border
of the sun, which appeared like a protuberance from the planet,
and which continued several seconds. This dark ligament is repre-
sented, in the drawings which accompany the several memoirs on
this subject, to be much thicker, and to continue longer, than the
dark lines in a solar eclipse j so that the planet, during the progress
of the ingress and egress, assumes a shape which has been variously
described as resembling a pear, a Florence flask, and a skittle. But
all the accounts agree in stating the sudden rupture of the ligament,
and that immediately thereon the planet assumes its usual circular
shape. Nothing of this kind, however, has been noticed at the
transits of Mercury over the sun : on the contrary, we have the di-
rect evidence of Sir William Herschel (who examined Mercury, with
that special object in view, at the transit of November 9, 1802),
that he could not discern anything out of the usual course. He ex-
pressly states, that the whole disc of Mercury was as sharply defined
as possible ; and that there was no kind of distortion of the limb,
either at its ingress or egress: the appearance of the planet re-
mained well defined from first to last.

Mr. Baily considers, and adduces certain facts to show, that the
circular edge of the moon is always distorted at those points which
are in contact (or nearly so) with the sun's circumference j and
which have occasionally given rise to the supposition of lunar moun-
tains in high relief*. He thence infers, that all measures of the
moon's diameter, when passing over the sun's disc, must be taken
with great caution, and with due attention to the proximity of the
[* See Lond. and Edinb. Phil. Mag., vol. ix. p. 73. — Edit.]

Third Series. Vol. 10. No. 60. March 1837. 2H

234? Intelligence a?id Miscellatieous Articles.

'to

part measured to the edge of the sun's disc (where alone the distor-
tion seems to take place), otherwise errors and discordances will
occur. Those prodigious lunar elevations and depressions, so fre-
quently described in solar eclipses, are seldom or never seen, ex-
cept at the commencement or termination of the eclipse, or in places
near the solar cusps : that is, in those points only which are near
the edge of the sun ; every other portion of the moon's circum-
ference being comparatively smooth and circular. If this notion be
correct, it would seem that the measurement of the solar cusps
during an eclipse may be liable also to discordances from this very
cause.

Mr. Baily concludes, by expressing a hope, that, at the total
eclipse of the sun in 1842, and the annular one in 1847 (both of
which will be central in Europe), the attention of astronomers will
be directed more particularly to this subject, both as to its existence
and its cause; and that such a regular system of observations in
various places will be adopted, as may best tend to elucidate and
explain this very remarkable phaenomenon.

There was laid on the table, for the inspection of the members
present, a small floating collimator, made by M. Amici. This in-
strument was only 11 inch in length, and, together with the mercury
on which it floats, was packed in a small round box, 2 inches dia-
meter in the inside, and 2 inches high, which might be carried in
the pocket. It is intended for voyagers, and other persons, to
whom a larger instrument would be a great inconvenience. It was
the first that had ever been made of such small dimensions.

There was also laid on the table a drawing, or representation, of
several shooting starsy that were observed at Plymouth from the
11th to the 14th of November last, together with the direction
which they severally took, as compared with the fixed stars then
visible.

II. Stars observed with the moon at the Royal Observatories of
Greenwich nnd Edinburgh, and the Observatory of Cambridge, in
the month of November, 1 836.

XL VI I. Intelligence and Miscellaneous Articles,

ON THE SYMMETRIZING POWER OF THE EYE. BY THE REV.
J. G. MACVICAR, A.M.

To the Editors of the Phil. Mag. and Journal of Science.
Gentlemen,

THE many interesting communications which have appeared in
your Journal of late years on the subject of vision induce me
to send an account of the following experiment, in the hope that it
will not be unacceptable.

Let the surface of a glass mirror be sprinkled over with some
powder, as, for instance, with flour from a dredging box. This

Intelligence afid Miscellaneous Articles. 235

done, on looking perpendicularly down upon the reflecting sur-
face, at the distance of distinct vision from it (unless the eye be too
long-sighted), the powder will appear, not irregularly scattered, as
it really is, but symmetrically distributed in two systems of beauti-
ful radiations, having the pupils of the eyes for their centres.

The phenomenon is sufficiently remarkable to strike even those
who are not otherwise curious in such matters. It may be observed,
however, that as every eye cannot catch it at once, it is better to
commence by using one eye only, as this gives only one system of
radiations, which, being more simple, is more easily observed. If
this phaenomenon has not been already attended to (and I do not
recollect to have seen it noticed anywhere), it is, I think, well wor-
thy of investigation. Some facts are, indeed, immediately obvious
respecting it. Thus, as to the region in which the physical part of
the phaenomenon takes place, it plainly appears that it is not either
the humours or retina, as is generally supposed in reference to other
phaenomena of the same order, but a more deeply seated part of the
apparatus of vision. For if it were any of the anterior parts, or even
the retina itself, the centre of the radiant system would certainly
change its place when the eye was made to wander over the mirror*.
In point of fact, however, that centre does not change place except
when the whole head is moved, in which case it does so proportion-
ally.

I ascribe the phaenomenon to a peculiar mode of action in the
nervous part of the apparatus of vision proper to it as an elastic
tissue, in virtue of which it tends, like the tissues and media expe-
rimented on by Chladni, Savart, Faraday, and others, and doubtless
all elastic tissues and media, to distribute all motions impressed upon
it in symmetrical systems ; a view of the matter having very in-
teresting bearings upon the principles of taste, — during the investi-
gation of which it was that this experiment first occurred to me, —
and one calculated to explain several seemingly unaccountable phae-
nomena as to the distribution of sensibility in the retina.

Johnfield by Dundee, Oct. 14.

STARCH.
M.Payen,in a memoir on starch, considers that this'substance, in
whatever manner or from whatever part of vegetables it may be ob-
tained, whatever may be its form, its age, or its state of aggregation,
has always the same chemical constitution: its conversion into dex-
trine by diastase, sulphuric acid, potash, «&c., are modifications of
its physical properties, without in the least degree altering its che-
mical constitution, which is represented by C2 }\h Qs. — Jour, de
Pharmacie, Oct., 1836.

ON THE ACTION OF SULPHUROUS ACID ON STEEL.

The experiments which M. Vogel has made on this subject lead
to the following results :

*[ We do not feel certain that this would be the case, if the seat of the
symmetrizing power be in the retina. — EpiT.]

2H3

236 Intdligence and Miscellaneous Aiiicles.

1st. A quantity of liydrosulpliuric acid gas is formed during the
action of sulphurous acid upon steel, which is not disengaged, but
is decomposed as soon as formed, by the sulphurous acid, which
causes the separation of sulphur.

2nd. Liquid sulphurous acid, which has been digested for a suffi-
cient time upon steel, contains, besides the sulphite, a portion of
hyposulphite of protoxide of iron, and this solution, when neutral,
partially reduces the proto- and per-salts of mercury.

3rd. Concentrated liquid sulphurous acid, digested in close ves-
sels with excess of steel, forms small crystals of a greenish white
colour, which are insoluble in water, and act like a hyposulphite of
iron with excess of base.

4th. The residuum which is left when steel is treated in close
vessels with a sufficient quantity of sulphurous acid, is not pure car-
bon, but consists of carbon mixed, besides sulphur, with a basic hy-
posulphite of iron, which is difficultly soluble in sulphurous acid,
and which shows that that acid is unfitted for analysing steel or
iron. — VInstitut.

ANALYSES AND CHARACTERS OF MINERALS, BY M. KUDER-
NATSCH AND COUNT SCHAFFGOTSCH.

The analyses of which the results are given below were per-
formed in the private laboratory of Prof. H. Rose.

Tin pyrites. Analysed by M. Jos. Kudernatsch. (From Pog-
gendorff's AnnaleUf Band xxxix. Stiick 9.)

Sulphur 29-61'

Tin 25-55

Copper 29-93

Iron 1244

Zinc 1-77

Earthy matter 1*02

99-81
Tlie composition of this mineral may be represented by the
formula

Tennantite. Analysed by M. Jos. Kudernatsch. (From Pog-
gendorfF's Annalen, Band xxxviii. Stiick 2.)

Sulphur 27-76

A rsenic 1 9*10

Copper 48-94r

Iron 3-57

Silver a trace

Quartz 008

The probable formula for tennantite is
Fe'^ 1

99-45

Intellmence and Miscellaneous Articles, 237

•^ts

Jamesonite from Estremadura. Analysed by Count F. ScliafF-
gotscli. (From PoggendorfF's AnnaleUi Band xxxviii. Stuck 2.)

The specimens analysed were readily cleavable in a direction
perpendicular to the axes of the crystals, and with some difficulty
in several directions parallel to the axes of the crystals. Lustre,
metallic. Colour, dark lead-gray. Streak, blackish gray. Hard-
ness, a little greater than that of rock salt. Specific gravity
= 5'616 at 19° cent.

Lead 39-971

Antimony 32*616

Sulphur 21-785

Iron 3-627

Bismuth 1-055

Zinc 0-421

99-475

The following analyses of Augite, Amphjbole, &c., by M. Jos.
Kudernatsch, are from PoggendorfF, Band xxxvii. Stiick 4.

Augite from Zigolon-Berg in Fassathal. Specific gravity = 3358
at 17° R.

1. 2. Oxygen in 2.

Silica 50-09 50-15 26-05

Alumina 4-39 4-02 1-87

Lime 20-53 19-57 5-49

Magnesia .. 13-93 13 48 5-21

Oxide of iron 1M6 12-04 2-74

100-10 99-26

Augite from Gillenfelder Maar in the Eifel. Specific gravity
= 3-356 at 17° R.

1. 2. 3. 4. Of Oxygen in 4.

Silica 49-79 47*05 4876 49-39 2565

Alumina'... 6-67 5*16 4 99 6-00 2 83

Lime 22*54 23-77 23-26 22-46 6*30

Magnesia .. 12*12 15*35 J5-78 13-93 5*39

Oxide of iron 8-02 7*57 7-21 7*39 1-68

99-14 98-90 100-00 9925
Augite from the Rhcengebirge. Specific gravity = 3*347 at 17° R.

1. 2. Oxygen in 2.

Silica 501 1 50-73 26-35

Alumina 6-68 647 3*02

Lime 18*66 18 90 5-30

Magnesia .. 15 72 16 91 6-54

Oxide of iron 7*55 7 26 1*64

Augite from jEtna. Specific gravity = 3-359 at 17° R.

Oxygen.

Silica 50-55 26-26

Alumina 4 85 2-26

Lime 22*29 6*26

Magnesia 1301 5*03

Oxide of iron 796 1*81

98-66

238 Intelligence and Miscellaneous Articles,

Augite from Vesuvius.

Oxygen.

Silica 50-90 26-44<

Alumina 5 37 250

Lime 22-96 6-4.4.

Magnesia 14 43 5-58

Oxide of iron .. 62b 1-42

9-99

Uralite from the neighbourhood of Lake Baltym, in the Ural.
The Uralite is a kind of hornblend, but possessing the crystalline
form of augite*. It forms crystals from 1 to 2 lines in length, which
lie scattered in a grayish green matrix. They are of a blackish green
colour delicately striped on the surfaces of cleavage, of a pearly
lustre, faintly transparent at the edges, and possessing the hardness
of apatite. A small quantity of the crystalline matter having been
carefully separated from the matrix, had, according to G. Rose, the
specific gravity of = S-150. This same quantity submitted to
analysis gave

Oxygen.

Silica 33 05 27-55

Alumina 4-56 2-12

Lime 12-47 3 50

Magnesia, with a trace ) j^-qq 4-99

of manganese ..../'

Oxide of iron 16-37 372

99-35

Amphibole from Kienrudgrube, near Konigsberg in Norway.

Oxygen.

Silica 4907 25*49

Alumina 924 4-31

Lime 10-33 2-90

Magnesia, contain- 1 ^q-oq 7-85

ing manganese j

Oxide of iron 9*77 222

98-70

Amphibole from the village of La Prese between Bormio and
Tirano.

Silica 45-31 23-53

Alumina 11-88 5-54

Lime 10-49 2-94

Magnesia,contain. 1 28 5-52

ing manganese j

Oxide of iron .. 15*93 3*26

Titanic, acid with 1 ^ ,.^

some silica . . J

98-55

♦ G. Rose has given a description of this mineral in Poggendoi-ff 's
Amialen der Pht/sik und Chcmic, Band, xxxiii. p. 21.

Intelligence and Miscellaneons Articles. 2S9

No attempt was made to determine the quantities of fluorine
which these specimens of amphibole probabl}' contained.

Phigionite.

Lead 40-98

Antimony 37'53

Sulphur 21-49

10000
This result agrees very closely with that obtained by Professor
H. Rose. Its formula is 4 Pb S -f 3 Sb S '.

CORRECTION OF AN ERROR IN MR. WETHERELL's PAPER, AND

NOTICE OF Venus Motrisii, a new fossil shell, by j. de

C SOWERBY, ESQ., F.L.S.

The following is a correction of an error in the list of fossil shells
given in Mr. Wetherell's observations on sonie fossils of the London
clay, published in the London and Edinb. Phil. Mag., vol. ix. page
464. (No. 56, for Dec. 1836.)

Among the Conchifera yenns incrassata is mentioned as occurring
in the Hampstead Well andatBrackenhurst; this is an error: the shell
found at these places and at Heme Bay, and several other places in
Kent, proves, upon careful comparison with the V. incrassata of
Mineral Conchology, to be quite distinct j it has a much more slen-
der hinge, and is wider in proportion to its length. Having been
indebted to Mr, Morris for this discovery, which is important be-
cause the true V. incrassata belongs to the upper marine formation,
it is desirable to commemorate the fact by naming the new shell
Venus Morrisii. I have taken upon me to correct this error be-
cause it originated with me. J. De C. Sowerby.

Camden Town, Dec. 19, 1836.

METEOROLOGICAL OBSERVATIONS FOR JANUARY 1837.

Chiswick, — Jan. 1. Clear: snowing : severe frost at night. 2. Frosty and
foggy. 3. Slioht thaw : hazy : clear. 4, 5. Overcast. 6. Rain: fine.
7. Clear. 8. Frosty : clear. 9. Overcast. 10. Boisterous : cloudy.

1 1. Clear and frosty. 12. Overcast : stormy. 13. Rain. 14, 15. Clear and
fine. 16. Hazy. 17 — 19. Foggy. 20. Rain : densely foggy. 21. Cloudy.
22. Rain. 23. Rain : fine. 24. Fine. 25. Cloudy: rain. 26. Heavy
rain: cloudy and stormy at night. 27, 28. Bleak and cold. 29. Snow.

30. Overcast : drizzly. 31. Fine.

Boston. — Jan. 1. Cloudy. 2 — 4. Fine. 5. Cloudy. 6. Fine: rain
early A.M. 7. Rain : rain early a.m. 8. Fine. 9. Cloudy. 10. Cloudy:
rain A.M. 11. Fine. 12. Fine: stormy with snow and rain p.m. 13. Rain.
14. Stormy. 15. Fine. 16. Cloudy : rain a.m. 17, 18. Cloudy.

19. Cloudy: rain p.m. 20, 21. Cloudy. 22. Rain. 23. Cloudy: rain a.m.
24. Cloudy. 25 — 27. Rain. 28. Cloudy. 29. Snow. 30. Rain.

31. Cloudy.

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T H E

LONDON AND EDINBURGH

PHILOSOPHICAL MAGAZINE

AND

JOURNAL OF SCIENCE.

[THIRD SERIES.]

APRIL 1837.

A

XLVIII. All Account of a new Voltaic Battery, being a Mo-
dification of the Construction recommended by Mr. F'araday.
By Mr, James Young, Chemical Assistant in the Andersonian
University,*'

[With Figures : Plate U.]

PLAIN working battery, containing a considerable num-
ber of pairs of plates, arranged on the principle of the
pile of Volta or the trough of Cruickshanks, is the instru-
ment which we habitually have recourse to for illustrating
chemical decompositions, and the other effects of voltaic elec-
tricity requiring considerable tension. Various constructions
of this battery are in use, of which we are concerned only with
that originally suggested by Dr. Hare, but of the value of
which electricians were not aware till it was clearly demon-
strated by Mr. Faraday f. The existence of a defect, however,
is fully admitted by Mr. Faraday, in the construction which he
recommends. To prevent metallic contact between contiguous
copper plates, cartridge paper is interposed between them.
The paper l>ecomes saturated with the acid solution used as
the exciting liquor, and the acid cannot be washed out of the
paper, but is retained by it after the battery is laid aside, and
may then occasion the solution of the copper, seeing that zinc
no longer enters into a circle with the acid and copper, and

* Communicated by the Author.

-j- Dr. Hare's paper describing his battery will be found in Phil. Mag.,
First Series, vol. vii. p. 284; and Mr. Faraday's in Lend. andEdinb. Phil.
Mag., vol. viii. p. 114.— Edit.

Third Series. Vol. 10. No. 61. April 1837. 2 I

242 Mr. J. Young's Account of a new Voltaic Batten/,

therefore the latter is unprotected. These papers require
likewise to be renewed occasionally, and they give to the con-
struction the character of a temporary arrangement. It is
true that glass or porcelain plates may be placed between the
contiguous coppers ; but these are inconvenient, and, in fact,
bring us back to the old construction of the trough partitioned
into cells. It is to be noticed too that these cojiper surfaces,
■with the paper between them, are lost, and turned to no ac-
count in collecting electricity.

After constructing several batteries with the interposed
papers, and becoming fully sensible of the annoyance which
the papers occasion, an arrangement of the plates suggested
itself which does not require interposed papers, and in which
both surfaces of the copper as well as of the zinc plates are
made available. Within the last eighteen months I have con-
structed several dozens of instruments of the construction to
be described, and having compared them experimentally with
batteries of the same extent of copper and zinc on Dr. Hare's
construction, I am prepared to state that, from the same sur-
faces of zinc, electricity the same in quantity and tension is
produced in both forms, but that in the new construction this
effect is produced with half the quantity of sheet copper, which
arises from both sides of the copper plates being presented to
surfaces of zinc. The new construction has, I believe, all the
advantages of approximation of the plates and compactness of
Dr. Hare's battery, which have been pointed by Mr. Faraday,
without the great and acknowledged drawback of the inter-
posed papers.

The sheet copper and sheet zinc to be used in this battery
are first cut into long ribbons, of the breadth which it is in-
tended to give the plates. Suppose the ribbons two inches
broad ; both the copper and zinc ribbons are then divided
into lengths of five inches, and a portion cut out as in fig. 1.
The slip is thus divided into two squares of two inches each,
which are connected at A, and a piece is left projecting at B.
The zinc and copper sheets are cut up exactly in the same
way. Fig. 1 therefore represents either a single zinc or a
single copper plate. The plate is then bent at A, and pre-
sents the appearance represented in fig. 2. In fig. 3, we have
two plates, one of copper C, and the other of zinc Z, which
are exactly alike in construction, but are placed differently,
as shown in the figure. Thin projecting parts B B are sol-
dered together, and this is the only metallic communication
between them which is allowed to exist. Fig. 3, therefore, is
only one copper and one zinc plate, or it is one pair of plates.
Each pair is made up in the same way. In arranging a num-

being a Modification of that recommended, hij Mr. Faraday. 2'1?3

ber of pairs to form a battery, they are interlaced so that a
copper square comes in between each couple of zinc squares,
and a zinc square between each couple of copper squares. It
is easy to see how this arrangement can be made, when the
plates are in the hand, though it is difficult to describe it. At
the positive end of the battery there is a single copper plate,
which is soldered at the top to the last double copper plate, as
seen in fig. 4 ; which figure represents three pairs properly
arranged, and also the manner in which they should be fitted
up and kept steadily apart in a wooden frame. This frame
consists of two cross-bars, e e^ ^ ^, in front, and the same be-
hind, dovetailed into solid ends. The channels in the cross-
bars, for the reception of the edges of the plates, are formed
by placing the four cross-bars together, and sawing a httle
way into one side of them all, every eighth of an inch or so in
their length, so as to form a set of parallel grooves. We have
by means of this frame a much greater security that no me-
tallic contact will occur between contiguous plates, than when
they are separated by wedges of cork, as in Dr. Hare's con-
struction, which may slip out.

The frame and plates are introduced into a trough, which
may be of wood or stoneware, containing the exciting liquor.
Dr. Hare's revolving arrangement of the two connected troughs
may be adopted for this battery, although we have been led
to give a preference in practice to a single trough to contain
the frame. To the solid ends of the frame are attached two
cords, which are fixed to two pulleys, on which they are wound
up, on turning a winch, as represented in fig. 5, by which
means the frame and battery can be raised out of the fluid.
If the axis (a stout wire) on which these pulleys are fixed
can be moved a little backwards and forwards on its bearings,
it is easy, by means of a little projecting peg at P, which fits
into a hole in the side of the pulley, to fix and support the
frame in a position above the trough, and out of the exciting
fluid, when that is desirable. But the form of the trough to
contain the frame and plates may be varied according to the
object in view, or the purposes to which the battery is to be
applied.

In comparing a battery of the form described above, either
with Dr. Hare's or any of the other forms in use, it is to be
remembered that the plates or elements of the battery are all
of double the size they appear to be, or that in this construc-
tion you have half the number of pairs, but each of double the
dimensions of a pair in any of the old batteries having the same
appearance.

A small battery of this construction, containing twelve pairs,

2 12

244 Mr. De la Rue on the Effects of a Voltaic Batter?/

of two inches breadtli, of plates (the size which we have taken
above as an example), may be contained in a trough eight
inches in length, and will evolve, when its terminal wires are
soldered to a Faraday's volta-electrometer, six or seven cubic
inches of the mixed gases in three or four minutes, with a
charge of half an ounce of sulphuric acid and half an ounce
of nitric acid, in twenty-four ounces of water, (all by fluid mea-
sure,) and is therefore amply sufficient to demonstrate the de-
composition of water on a considerable scale.

It is proper to use the thickest sheet zinc which can be
had, in the construction of the plates, although the thinnest
sheet copper will suffice, from its being so well supported.
When the zinc plates are worn out, the cross-bars may easily
be pulled out of the solid ends, and the elements of the bat-
tery separated. New zinc plates being soldered to the old
coppers, the whole may again be quickly rearranged in the
old frame.

Glasgow, Jan. 4, 1837.

XLIX. 0?i the Effects of a Voltaic Battery charged with Solu-
tion of Sulphate ofCopjwr. By Mr, Warren De la Rue.

[With Figures : Plate II.]
To the Editors of the Philosophical Magazine and Journal,
Gentlemen,

IN answer to your query (vol. ix. p. 484<,) as to the relative
effects of batteries charged with sulphate of copper or with
acids, I beg to submit to your attention the following facts
and deductions.

It is well known that in connecting the poles of a battery
with a definite length of wire, the wire will become ignited,
and continue so for an exceedingly short space of time after
immersion in an acid ; and if the battery be immersed without
connecting the poles and allowed to remain for a few minutes,
and the connection be then made, — with the same length of
the same wire, — no ignition whatever is produced*. As in
this latter case no zinc can have been deposited on the copper
plate, prior to the connection of the poles, it follows that this
decrease of power must result from some other cause. At the
moment of immersion in dilute acid, say sulphuric, the elec-
tricity is produced by the combination of the acid with that
portion of oxide which is in perfect contact with the zinc
plate: when this thin coating of oxide is removed, the zinc
plate is then oxidized at the expense of water, hydrogen be-

• A battery regains its former power by exposing the plates to the
action of the atmosphere.

charged xmth a Solution of Sulphate of Copper. 24-5

ing set at liberty ; and as the hydrogen assumes the gaseous
form, it annuls or carries off a large portion of the electri-
city*.

If sulphate of copper be used in charging the battery in-
stead of acid, oxygen is supplied to the zinc by the oxide of
copper; no evolution of gas, therefore, takes placet; and the
action is thus rendered continuous, the effect being fully equal
to that momentarily produced by immersion in acids. The
fusion of metallic points of very large dimensions, the decom-
position of fixed alkalis, &c. &c., cited in my former commu-
nication as the effects of a voltaic battery of 100 pairs on
Cruickshanks's construction, cannot be produced by the same
battery when charged with acid, the momentary power being
exhausted before the battery can possibly be brought into ac-
tion |.

The following is an experiment to ascertain the effect on the
battery produced by the deposition of copper on the zinc plate.
Fig. 10 represents one of the zinc plates of the battery : round
it at («) are placed four copper wires one tenth of an inch in
diameter; these are each attached to the plates by a drop of
solder. Fig.l I shows the zinc plate surrounded by the copper as
in Wollaston's plan : the battery consists of twelve such series.
It is clear that there are four small local currents in each cell ;
yet the power of the main current is increased, and not dimi-
nished as I conceived it would have been. From the proxi-
mity of the copper wires to the zinc plate, there is no deposi-
tion of copper on the zinc plate; it adheres to the copper wires
so firmly that it is exceedingly difficult to remove.

I find that amalgamating the zinc greatly increases the
power of the battery, and prevents the strong adherence of the
copper to the zinc plates, which are therefore cleaned with
facility §. I have a battery of 30 pairs of four-inch plates

* A similar effect takes place in the formation of steam, which causes the
gold leaves of an electrometer to diverge with negative electricity.

Professor Faraday has shown that a voltaic current ceases to affect a
magnetic needle if employed in the decomposition of a solution of iodide of
potassium : hydrogen is given off in this case. Again, if a battery be euj-
ployed in decomposing a solution of a metallic salt, an atom of it will be
decomposed for the solution of every atom of zinc ; but this does not de-
stroy the current, for an atom of water is at the same time resolved into
its elements.

f The exceedingly small quantity produced by the local action cannot
be taken into account.

X This fact I am ready to prove by actual experiment to any scientific
gentleman who will do me the favour to call for that purpose.

§ The zinc plates are anralgamated by rubbing them with dilute nitric
acid and mercury ; the mercury is allowed to be absorbed by the zinc plate,
and the operation muat then be repeated, which is a requisite condition.

246 On a Voltaic Battery charged with Sulphate of Copper,

with amalgamated zinc, which is well adapted to the use of
sulphate of copper; it is more (Economical in its construction*
than any now in use, and possesses this great advantage, that
the zinc when worn out may be easily replaced. Fig. 6 shows
the zinc plate, which must be tinned on the top Af prior to
the amalgamation of the rest of the plate; B B are two slips
of wood grooved out to within threeTourths of an inch of the
bottom, and intended to retain the zinc plate in its proper
position. The copper plates are formed into cells, as repre-
sented in fig. 7, five inches square and one inch wide : E E
are two ears of copper, by which the cell is suspended in its
place ; A is a slip of copper to form a connection by means
of solder to the zinc plate in the adjoining cell. The cells
are painted on the outside to protect them from the action of
acid. The zinc plates do not descend lower than within three
fourths of an inch of the bottom of the cells, so that the space
left may contain the deposit resulting from the decomposition
of the sulphate of copper. The cells are supported in a long
wooden frame by the ears E E and retained in their place by
tacks driven through them as represented in fig. 9. Fig. 8
represents a contrivance by which the charge may be renewed
while the battery is in action : at the top of each cell may be
placed a lip or spout L, a quarter of an inch deep; these
must overhang a wooden gutter running the length of the
frame. The solution must be renewed with a funnel having a
long neck, the long end being inserted nearly to the bottom of
the cell ; when fresh solution is poured in, the spent licjuor
will run out of the lip into the gutter.

Immediately after a series of experiments the battery must
be emptied, and the plates well cleaned by dashing water be-
tween the cells. If this be not immediately attended to it will
be exceedingly difficult to remove the deposit from the cells.
A Cruickshanks's battery is best cleaned by laying it on its
side. I remain. Gentlemen, yours, &c.

110, Bunhill Row, Dec. 7, 1836. Warren De LA RuE.

P.S. The fact related in your first note (vol. ix. p. 48 i)
shows that Professor Daniell had no intention of employing
sulphate of copper in an ordinary battery ; he inmiersed a
zinc plate in sulphate of copper and found that there was local
action, from the deposition of copper ; but he went no further.

• The one I have, cost altogether 3/.; but as I put this together myself,
a similar battery constructed by workmen would of course be rather more
expensive.

t This is effected by filing the top smooth, wiping it over with a little
muriate of ammonia, and then dipping the top in a ladle of melted tin, a
little tallow being placed on the tin to prevent the surface from oxidating.

[ 247 ]

L. A B-e-port of the Progress of Phytochemistry in the year
1835, in reference to the Physiology of Plants. By J. Cl.
Marquart.*

nPHE experiments on starch which were mentioned by
"^ M. Meyen in his Annual Report on Physiological Botany
for 1834' tj have been continued in various ways. According
to the experiments of MM. Payen and Persoz:]:, starch con-
sists of 995 p. m. interior substance, which they call amidone,
and 3 p. m. teguments. The other two thousandth parts they
reckon as carbonate and phosphate of lime with silica. They
found also in the starch of native plants a disagreeably smell-
ing oil, soluble in alcohol, which was not contained in exotic
starch. Amidone is insoluble in water as long as it remains
unchanged ; it only swells in it, and then passes through se-
veral filters.

The apparent solubility of amidone in water of 65 — 70°
[Cent.] is therefore properly only a suspension of it, effected by
means of the greatest divisibility possible. The known qua-
lities of starch solutions belong to this amidone; neither dia-
stase nor iodine, &c., act on the tegument, whose nature is not
further characterized. The authors also critically illustrate
the results of M. Guerin's experiments (Annual Report for last
year, p. 145), and consider his amidine to be their amidone in
a state of great division, with a portion decomposed by his
method of experimenting; on the contrary, they regard his
amidin soluble to be amidone swelled by water. M. Guerin
soon answers these objections §, and maintains, supported by
experiments, that the amidone of MM. Payen and Persoz
consists of a soluble and an insoluble part. The dextrine^
which MM. Payen and Persoz formerly considered to be the
contents of the starch granules, is a product of the action of
acids on the amidone and is a mixture of sugar, gum, and ami-
done.

M. Guerin Varry studied || more attentively the action of
diastase on the starch granules, and found the doubt, already
expressed by M. Meyen in the Report for last year (p. 151)
to be true, that diastase is capable of rending the tegument of
the starch granule. The starch, which had been left un-
changed by hot water, remained, according to M. Guerin,
quite unchanged by diastase even by -f 20 — 26° Cent.; the
amidone, on the contrary, is changed by it partly into sugar

♦ From Wicgmann's Arcluv fiir Naturfj;eschichte, vol. ii. part iv. p. 131.

f See Wiej^inann's Arrhiv, vol.i. p. 143.

t Annates de Chimic ct (k Plit/nque^ Aout 1834, p. 337—371.

I Ibid., Sept. 1834, p. 108, 109. |1 Ibid. Sept. 1835, p. 32—78.

248 J. C. Marquart's Report of the Progress of Phytochemistry

even at 0°; it is even capable at —5—12° of rendering the
paste of starch liquid without at the same time forming sugar.
The conversion of starch into sugar takes place very rapidly,
as well in the air as in vacuo, and without the absorption or
disengagement of gas.

M. Guerin examined the starch under the microscope, and
appears, as is often the case with the French, to have had no
knowledge of the experiments made by the Germans on the
same subject. He observed, like M. Fritsche, the concentric
rings and the nucleus of the granules, and very improperly
names the latter the umbilical point ; he also found the mon-
Straus grannies of M. Fritsche, and describes them as a con-
nection of one or two granules which, on account of want of
space in the mother cell, had forced themselves on one another
so that the formation of hexagonal cells by the aggregation
of the original round cells could plainly be observed. The
umbilical point of each granule was always directed outwards.
M. Guerin, after having in this manner studied the form of the
granules, made experiments on the action of water on them at
various temperatures, sometimes using pure water, sometimes
water and diastase; from which it appears in general, that at
50 — 53° C. the water with or without diastase had no effect
on the granules; at 54' — S5^ he perceived some torn granules,
and at 59 — 60° several granules quite torn, and many already
empty; at 62° all the granules torn and enipty, yet so, that in
diastase the husks were only split, but in water broken down
into shreds, [gefranzt).

Of more importance are the remarks of M. Hartig on the
appearance and function of starch in the vegetable kingdom,
in his memoir '^ On Starch, Cambium, the nutritive sap and
milk-sap of woody plants, in reference to phytochemistry, che-
mistry, and common use*." M. Hartig found in the woody
body of all deciduous trees after the fall of the leaves a great
quantity of starch (up to 26 per cent.), which in spring, as soon
as the sap begins to ascend, gradually diminishes from the pe-
riphery to the centre, being dissolved by the carbonated water
ot the ascending stem. With this solution there appears to
be connected an action on starch similar to the known action
of the weak mineral acids in the first moments ; namely, the
reaction of iodine has ceased and gum is formed, the solution
of which forces its way through the medullary rays to the bark
and here forms the basis of the young wood. For according
to the author, Cambium is the young cellular tissue, over-
charged with sap, forming activejuices (Bildungssafte), and not

♦ Scluvcigger and ErUinann, Journ.filr jiraUuchc Clicmie, vol. v. part iv.

in the Y^ar 1835, in reference to the Physiology of Plants, 249

the descending sap which has been prepared in the leaves, since
we find it already in the stem when the leaves have not yet
sprouted, and only completely developed leaves are capable of
an assimilating process.

M. Du Menil found in his examination of the bark o^Pinus
sylvestris, in 1000 parts, 60 parts starch*. According toDu
Menil the bark was separated from the alburnum ; as however
non-botanists possess in general erroneous conceptions of bark,
liber and alburnum, we do not know what Du Menil has
examined ; very likely what he separated from the bark was
the young wood. M. Nardo, who examined the bark of Pi-
71US mai'itimaf, found in it no starch, and the question is,
whether this difference of results depends on the time of the
year, or on the method of examination. M. Proctor ascer-
tained the occurrence of starch in the bai*k of Prunus virgi-
nianaX^ as did J. Martin in the leaves of Cassia marylandica^,
M. Payen |1 examined the tubers of Oralis crenata, which were
recommended as food, and found in the younger kinds 2*5 per
cent, starch, and in the older ones 10 per cent* Those granules
of starch, which are inclosed several in one cell, are more un-
even and irregular than those of most of the other kinds. The
results of an analysis of the tubers of Cyperus esculentus, by
M. Semmola^ deserve also to be mentioned; among other
substances, he states that he found 224- p. m. starch, and 43
p. m. inulin ; these results, however, want confirmation.

M. Julia Fontenelle** made known some interesting remarks
on corn which had been buried in the earth for a considerable
time. A corn magazine in the citadel of Metz, built about
300 years ago, contained corn from which good bread could
be made. M. Passalaqua brought from the ruins of Thebes,
some species of fruit, the production of which he supposes to
have taken place above 3000 years since. By examination
the corn was found to be a little acid, to have lost its gluten,
but to have retained the "whole quantity of starch, A bread,
even as old as the above-mentioned corn, found in a mummy,
contained a quantity of germinated and lightly roasted grains
of barley, which also contained an acid, no gluten, and much
starch.

Inulin was formerly obtained only by boiling the parts of
plants, by which operation it sank as powder from the hot
decoction. After what we have learnt on the changing action
of boiling water on starch, and those bodies related to it,

* Archivfur Pharmaciey vol. i. Part i.
t Isis, 1834, Partvi. vii. p. 670.
: Journ. de Chimie Med., 1834, p. 674.
§ The American Journ. of Pharm., 1835, April, p. 19 — 24.
II Journ. de Chimie Med., 1835, May. t Ibid. *♦ Uid., 1834. Feb-
Third Series. Vol. 10. No. 61. April 1837. 2 K

250 J. C. Marquart's Report on the Progress of Phytochemisiry

inulin could not be considered as an unclianged part of the
plant, and I (M. Marquart) therefore made several experi-
ments on it* to separate the unchangeable matter, to which
inulin owes its origin. I succeeded in insulating from thick-
roots (tubers so called) of Gcorgina variabilis a milky liquid
(by the method for making starch): the milkiness, as could be
perceived on its being greatly magnified, was caused by very
small globules, which were quite diaphanous and round, dif-
fering from the starch granules in not settling from the liquid
and not being coloured blue by iodine. I, however, succeed-
ed in separating them by freeezing the liquid, and was able
to wash them with water and to examine them more closely.
I discovered in them the basis of the substances which have
been named Inulin and Dahlin, and intend to give to the first
the name of Synantherine^ on account of its occurrence in the
Composited or Synantherce, and to consider it as a substance
analogous to starch. 1 propose for the two last substances the
name of Sinistrine, on account of their analogy with Dextrine,
as Biot and Persoz have already discovered that inulin turns
the plane of polarization to the left.

M. Koene, who examined the roots of Anacyclus Pyrethrum^
extracted from them 57 per cent, of inulin (sinistrine)f, which
is remarkable on account of the quantity, if there is no error
in his statement. The mealy sediment of lichens (Flechten-
satzmehl), the original form of which we are yet ignorant of,
presents a similar case. M. Guerinf has also examined this,
but only the soluble part, which he calls Lichenin. He pre-
pared it from Cetraria islandica, by filtering the hot decoction
and precipitating it with alcohol. After dissolving and precipi-
tating several times, it is in the dry state yellowish, swells in
water, and is then void of colour, smell, and taste. Lichenine
dissolves easily in hot water, less in cold ; the solution is co-
loured blue by iodine, but weaker than by amidine, with which
it has the same elementary composition, namely C5 Hj^ O^.
It forms sugar with sulphuric acid, and with nitric acid oxalic
acid in a much larger quantity than any other substance of
the vegetable kingdom, so far as we at present are acquainted
with vegetable substances.

M. F. Nees von Esenbeck^ wrote a supplement to my [M.
Marquart's] memoir on Inulin, in which he expresses the opi-
nion, that the so-named Bassorin is the insoluble matter of
the Bassora and tragacanth gums, the membranes of the torn

• Geiger and Liebig's Annalen der Phnrmacie, x. 1.

t Ann. de C/iimie et de Phynque, July 1835,

X Journ. de Chim. Med.y ix.

§ Geiger and Liebig's Ann. der Phcmn.

in the Year 1835, ifi reference to the Physiology of Plants, 251

cellular tissue, and endeavours to prove it from the nature
of this insoluble matter and from the manner of excretion
of these kinds of gums from the bark. According to the ex-
periments of Guerin * the elementary composition of this bas-
sorin is different from that of arabin (of the white soluble
gum), while cerasin, the gum of our Rosacece, is only di-
stinct from arabin by its difficult solubility, and by its being,
when long boiled with water, completely converted into ara-
bin, Bassorin consists of 10 m. g. carbon, 11 m. g. hydro-
gen, and 11 m. g. oxygen, while arabin is composed of 12
m. g. carbon, 10 m. g. hydrogen, and 10 m. g. oxygen. Ac-
cording to M. Guerin, starch has exactly the same compo-
sition as arabin ; he considers, however, starch to consist of
amidine and amidin tegume7itaire, and doe;^ not therefore call
both isomeric. Amidin tegumentaire has, according to Gue-
rin, the same elementary composition as the woody fibre,
namely, C7 H^q O4, which is not without influence on the views
of the structure of the granules of starch, and serves as a sup-
port to those who consider the starch granule as consisting of
a soluble interior and of a husk.

We have seen that by treating starch with acids and dia-
stase it was first converted into gum, and then into sugar ;
have learned that gum and starch have the same composition ;
and are now informed by Liebig's experiments, that crystal-
lized cane sugar is isomeric with pure gum, or is equivalent to
it in its elementary composition.

In physiology, the terms gum and mucus have the same
meaning, although chemistry distinguishes them. Those muci
which are stated by chemists to contain nitrogen merit a more
close examination. Thus M. Tromsdorff-f- lately found 7*5
per cent, of a mucus, soluble in water, containing nitrogen, in
the. fruit of Coriandimm sativum ; M. Pay en J, 0*1 per cent,
of a like substance in the tubers and stem of Oxalis crenata.
M. Herberger§ examined Sphcerococcits crispus, and found in
it 79 per cent, of a substance which he calls the gelatine of
algae, which according to our opinion, founded on the proper-
ties of the matter mentioned, does not differ from common
gum, being soluble in water and precipitated from the solution
by alcohol. The small proportion of nitrogen is not essential,
or is caused by some mixture. We consider the algae gelatine
of M. Herberger as cellular membrane, it being insoluble in
water and differing only from bassorin by the small quantity
of nitrogen it contains.

* Ann. de Chim., vol. xlix. p. 248. f Archivfur die Pharm.f ii. 2,

J Jfurn. de Chim. Med., Mai, 1835.
§ Buchn. Repert.f vol. xlix. part 1, 2, 3.

2K2

252 Progress of Phytochemistry in 1835.

M. Lassaigne* found uncrystallized sugar not only in the
])lants already known to contain it, but also 1 per cent, in the
leaves of Moms alba, M. Zenneck found nearly 6 per cent.f
in the fruit of Panicum miliaceum, and M. SemmolaJ found
12*5 per cent, of crystalline sugar in the radical tubers of Q/-
petiis esculenius, M. Malagutti§ has given a very good paper
on_sugar, from which we may remark that cane sugar is hy-
drated, i, e. changed into grape sugar, by all weak acids with-
out exception. The latter has been found in all acid fruits;
from this the process necessary to its origin becomes evident.
If the action of the acids on the grape sugar continues, water
is again taken from it, and ulmic acid is formed. If at the
same time the atmospheric air acts on it, oxidation takes place,
and by this the formation of formic acid.

The crystalline part of manna, mannite, was found by M.
Winckler in a preparation from the buds of the poplar ||, and
according to Boutron-Charlard and Guillemette^, thegrena-
din found in the bark of the roots of Punica Granatum is also
mannite. Grenadin acquires from this circumstance more
importance, and deserves a closer examination as to its occur-
rence.

We here again direct attention to the rather too much neg-
lected experiments of MM. Fourcroy and Vauquelin on the
sap o{ Allium Cepa, and of Laugier** on the sap of Daucus Ca--
rota. All three chemists found in the saps of those plants,
after they had begun to ferment, crystalline manna, which they
were not able to extract from the fresh saps. At the same
time the fermented saps indicate free acids, and, according to
Laugier, the manna from Fraxinus has in its fresh state a smell
of acid. Perhaps the natural or artificial process of originating
mannite might be a task worthy of chemical research.

M. Buchner, jun.f f examined the sap of the nectaries of
Agave geminiflora^ which flowered in autumn, 1834, in the
Botanical Garden of Munich. It possessed the consistence of
a thin syrup, specific gravity = 1*09, and contained a great
quantity of uncrystalline sugar, water, and traces of gypsum.
The sweetish putrid smell disappeared when in contact with
die air. M. Buchner, sen.^ examined some time back the
sap of the nectaries of Agave americana^ and Anthon that of
A, IkridOf which exhibited nearly the same qualities.
[To be continued.]

♦ JourtL. de Chim. Med., 1834. f Buchn. Repert. yVo\. xlix.

+ Joum. dc Chim. Med., 1834, p. 676. § Journ. de Pharvi. Sept. 1835.
II Buchn. Repert.y\o\. li. part 1. ^ Journ. dc Fharm.y April 1835.

#• Mem. du Mus. d^Hist. Nat., vol. iv. page 102—108.
tt Buchn. Reperi., vol. li.

[ 253 ]

LI. On a Double-bodied Intestinal Worm^ the Syngamiis
trachealis. By Dr. Charles Theodore von Siebold,
of Danzig.^

THIS remarkable parasitic animal, which I will here de-
scribe, was discovered about twenty-five years ago, but
its internal structure was imperfectly known, and the attention
was not paid to it which it merited. At the present time it ap-
pears to be quite forgotten, and I therefore present it again
to the friends of helminthology with its true structure and
with a new name ; perhaps I shall be able to procure for it a
determinate place in the system f.

The worm of which I speak must, according to its struc-
ture, be classed with natural monsters, and may justly be
placed by the side of Diplozoon paradoocum. The Diplozoon
paradoxum % can no longer be considered as the only known
double animal, for our Syngamus trachealis is also one, but with
this difference, that it does not consist of two hermaphrodite
animals closely connected together, but that a male am] Jemale
animal are grown together.

Before I begin the description of this monster I will state
what is already known of it. Montagu described this worm
as a Fasciolak, and has given an indifferent drawing of it ||, and
mentions as its habitat, the trachea of young hens, pheasants,
and partridges. He found twenty such worms in one wind-
pipe. Montagu ascribed to it a disease known in England by
the name of gapes, which often seizes the young poultry a short

• From Dr. Ar. Fr. Aug. Wiegmann's Archivfur Naturgeschichtej Part 11,
1836, p. 1 05. Translated by W. Francis.

[t Since the publication of this paper, a memoir by Nathusius, inserted in
the first number of Wiegmann's Archiv for 1837, proves the Syn. trachealis
of Siebold to be a species of Strongylus in the act of coitus. A translation
of this paper will appear in a future number of our Journal. —Edit.]

X I here take the opportunity of adding to the observation which has
been made on the circulation of the blood in the Diplozoon, (see Nordman's
jB«<mge,p.69, and myfirst paper in Wiegmann's ^rcAiu, Partl.,1835, p.58.),
the following correction. New observations which I have made on this animal
since the ciliary motion of Purkinje was made known, have convinced me
that the motion of the blood is not perceived in the vascular system of this
animal, but that the movement arises from the inner surface of the vascular
membrane, as Ehrenberg has lately stated in Wiegmann's Archiv^ Part II.
p. 128. The vessels possess on the inner surfaces moving cilia, which
exactly imitate the motion of the blood. This movement resembles the ci-
liary motion described by Henle (MUller's Archiv'^W. 6, p. 576.) in the tor-
tuous canals of the Branchiobdella parasita^ and which I also have seen in
this animal.

§ Account of a species of Fasciola, which infests the trachea of poultry,
with a mode of cure, by George Montagu, in the Memoirs of the Wernerian
Natural History Society, vol. i. for the years 1808, 9, 10. Edinb.Svo, p. 194.

II Ibid. Pl.vii.fig.4,

254 Dr. Von Siebokl 07i a Double-bodied Intestinal Worm^

time after their appearance from the shell, and kills them.
His account of the disease is as follows (p. 194): it "is a fre-
quent gaping, attended with an extension of the neck, like
suffocation, and sometimes an apparent phthisical affection or
irritation of the lungs." The neck and lungs of the fowls in
which this worm was discovered were found much inflamed.

The supposition of the editor of the Wernerian Memoirs
(p. 199.), that the worms, discovered also in the windpipe of
hens and turkeys by Dr. Wiesenthal of Baltimore (in the Me-
dical and Physical Journal^ 1799, vol. ii. p. 204.) resemble
those described by Montagu, I cannot confirm, as in those the
characteristic lateral process is wanting*. Rudolphi believed
Montagu's worm to be the Disto?nu?n lineare, which he had dis-
covered in the mucous skin of young poultry-j-; if, however,
Rudolphi's description of Distomu?n lineareX be compared with
that which the English naturalist has given of his Fasciola §,
there will be found a great difference between the two animals.

This is all that I have been able to find in scientific works on
this worm, and what satisfied me less, was to find upon close
examination of this worm how little its true structure was
known to Montagu. I have been fortunate enough to find this
parasitic animal in the windpipe of three different species of
birds, namely, in Phasianus Gallus, Picus viridis, and Cypselus
apus, I discovered a single one at first in October 1833 at
Heilsberg in a very lean hen; in May of the following year I
found among eleven chimney swallows, which were taken in
Heilsberg, in one bird two individuals at once, and a fourth
in a green woodpecker which was shot this year near Danzig.
I have in all my dissections of birds during two years, in which
time I have examined a great number, always searched the
trachea and its branches^ and have found the Syngamus tra-
chealis only in the three birds mentioned ; so that I must be-
lieve the worm is here a rarity, and only occurs occasionally
and alone, while in England it is found so often and collected
in such numbers in the windpipes of poultry, often committing

• I was not able to compare the work of Dr.Wiesenthal more closely.

t Rudolphi, Synopsis, p. 414.

j Rudolphi, Historia Natur. etc. vol. ii. 1. p. 414.

§ Wern.Soc, p. 197- " Body round, acuminated at the posterior end, the
lower aperture produced on a long stalk or arm, that extends rather beyond
the anterior end of the body, where the other aperture is placed, and is not
above half the size of that part : these openings spread a little, or are sub-
infundibuliform ; the larger appears to be the mouth, and is slightly sex-
partite; that on the arm is used as a sucker, and is the par*, by which it ad-
neres to the inside of the trachea: the divarication takes place at about one
fifth part of the length of the body : the colour is red, and the intestine*,
which are extremely numerous and tortuous, are white."

the Syngamus trachealis. 255

great ravages on the feathered tribe, that their owners have
been obliged to have recourse to a remedy for it.

The worm consists of an extended cylindrical body, divided
towards the upper part into two long branches: the two
branches vary in thickness. The thickest branch forms pro-
perly the anterior extremity of the body, and if we reckon
it to the whole length of the body, the other and more slender
branch extends from the junction of the middle and anterior
third of the body, making an acute angle with the anterior
extremity. The whole length of the body is nearly half an
inch, its thickness towards the hinder part 4 to J lin., the
thirmer branch is 1^ lin. in length and measures about ^ lin.
in diameter. In order to distinguish better the two branches,
I shall call the thick one the female branch and the thinner the
male branch, which I hope toprove in the course of this memoir.
The male branch is sometimes shorter, sometimes longer than
the female branch. The motions of this animal are very slow.
Its colour is brick-red, and equals in brightness that of the
lungs of birds ; at both heads the red passes into yellow. The
whole worm is transparent, and the red-brown intestine and
the convoluted generative organs are visible through its integu-
ment. If the worm be kept for some time in water, the red
colour disappears and a dirty yellow takes its place ,* the co-
lour of the male branch is always fainter than that of the body.
The heads of both branches are of the same structure, only that
of the male is inferior in thickness to that of the female. The
description of one branch may therefore suffice for both. I
found the worm at times with the head of one of the branches,
at times with the other, fixed to the mucous membrane of the
windpipe. This cephalic extremity, the upper free end of both
branches, is always inflated, and is contracted at the place
where the head, which by this operation has taken the form
of a ball, passes into the branch : exactly in the middle of the
head is a round wide aperture or mouth. The female branch
is very little bent; the male, on the contrary, has often the
form of an S or winds round the female branch. At the place
where both branches join is perceived, in the obtuse angle
which the male branch makes with the body, a slit-like aper-
ture or fissure (see Plate I. fig. 6. c), out of which I have seen
the eggs glide, and in which therefore we have to look for the
vulva. The body is bent down to its most inferior part in a
soft undulate form, and at its end is round and truncated;
from the middle of this blunt end of the body descend some-
times shorter sometimes longer arms or stalks. An anus was
nowhere to be found.

On examining the interior part of this animal, I found as
follows: The exterior skin surrounds, 'as \n xhe Nematoidea^

256 Dr. Von Siebold on a Douhle-lodied Intestinal Worm,

a cavity in which the intestines lie inclosed. The intestines
are here bathed by a red liquid, in which only a few vesicles
and particles swim. This is the liquid which imparts to the
worm the beautiful red colour. Whether the cavity of the
male branch stands in connexion with the cavity of the other
parts of the body, which are continued into the female branch,
whether it is separated from it by a partition, I could not de-
termine, on account of the small number of specimens which
I had to examine. On injuring the skin the red liquid flowed
out without the intestines being pressed forwards ; from which
I conclude, that the skin which covers the intestines does not
possess that elasticity which is common to the skin of the
cylindrical worms. The skin was almost even, and not as in
most of the Neinatoidea, annulate.

The circular mouth-aperture leads to a cavity of the form of
a basin, which does not consist, as in the Distomum, of a mus-
cular tissue, but of a firm horny substance of a dark colour,
which is visible through the skin : its outer border has six in-
dentations, and is so inclosed by the tegumentary covering
that it is everywhere kept at the same distance from it.

Opposite the mouth the basin is pierced by a small aperture,
through which we arrive at the oesophagus. I saw this aper-
ture surrounded by six minute knots or hooks. As I now
turn to the description of the digestive organs, I shall only
speak of the male branch. The oesophagus of the male branch
is very much prolonged, begins small at the inferior small
aperture, increases in the middle, and ends rather rounded.
Its colour is dirty yellow ; its structure, like that of many Ne-
matoidea, is very muscular, and is traversed by a trihedral
canal. Behind it commences the somewhat broader, more
simple, and red-brown-coloured intestine, which passes in a
tortuous manner to the branch, and terminates in a cul-de-sac
before the connection of the latter with the body. The oeso-
phagus of the female branch is just the same as the former as
to colour, situation, and structure, and is only shorter and more
compressed, from which it appears in the shape of a pear
turned upside down. The same red-brown simple intestine
which arises from it, is somewhat broad, extends in a more
tortuous manner through the whole body, and finishes in a
cul-de-sac before the caudal extremity. Both intestinal canals
contain very small granules, which may be well compared with
pigmentary molecules. On opening the intestinal canal only a
few of these molecules force themselves out, the rest remain
attached to the inner surface of the intestine. If a piece of the
intestine is examined under a microscope, it has just the ap-
pearance as if it possessed vascular reticulations, which is
caused by the molecules being separated into several heaps

the Syngamus trachealis. 257

and isolated specks, and by leaving unfilled furrows, which
cross each other, and give it the appearance of a vascular net.

Next to the intestinal canal, the generative organs of this
worm are the most striking. In the male is perceived a dirty-
white very thin vessel, which begins by an unattached slender
extremity near the middle of the oesophagus, and winds itself
down the intestine. The vessel becomes larger and larger as it
descends; and, with the last bend which it makes at the lower
end of the branch, it suddenly contracts and runs down as a
very slender canal to the above-mentioned slit. I could not
properly follow the end of this canal, as it was very indistinct
before the slit, and partly covered by two small long and
thin bodies. These long jjodies, which lay in the hinder ex-
tremity of the male branch, bent near the slit, consisted of a
horny substance, arid touched one another at an acute angle,
directed downwards. A fine white granular matter formed
the contents of this receptacle. The vessel could easily be
taken out entire by cutting off the branch.

A much more compound vessel, with the intestinal canal,
occupied the female branch and the other parts of the body.
There were here two vessels with blind ends which began in
the lower part of the cavity of the body, ascending the gut as
two very thin milk-white canals, with irregular windings and
twistings, and forming, chiefly at the beginning of the female
branch, several convolutions, one of which reached a great way
up the female branch and then returned. On their passage, both
receptacles decreased towards the middle of the body for a
short space, but soon changed into two thick dirty-white tubes,
which in breadth nearly equalled the circumference of the in-
testinal canal. Near the end of the gut these tubes bend, and
then turn upwards and reach the place where the male and fe-
male branches join, after both having formed some few and
small windings : here they are united into one vessel, and
send a very thin tortuous canal to the above-mentioned slit.
From the construction, order, and contents, I supposed this
double receptacle to be nothing less than the female generative
organs, such as we find in most of the Nematoidea. One could
easily distinguish the following parts on it, namely, 1st, The
two thin and milk-white vessels, situated in the back part, are
certainly the ovaries. They contained in their posterior con-
volutions a fine granular white substance; while in the an-
terior its granules were more firmly pressed together, and
on the ovarium being injured, escape adhering together in
a cylindrical form. Nearer to the upper part the granules
were clustered together in small heaps, so that the whole
matter appeared already to have separated in simple vitelli;

Third Series, Vol.10. No. 61. April iS 37. 2L

258 Dr. Von Siebold on a Douhle-bodied Intestinal TVorm,

none of these heaps of granules possessed a distinct mem-
brane or a clear partition. A bright spot appeared in some
heaps, which may probably be the germ*. 2nd, The small
narrow pieces of the two vessels which succeed the ovaria
may be compared with the fallopian tubes. Both vessels
were here so narrow, that never more than one grain at a
time could pass through the canal, while at the same time
four to five such granules were contained in the calibre of
the oviducts. By the extension of the two vessels the heaps
of granules take at once the form of oval eggs, and we can
suppose these two wide canals lo be, 3rd, The oviducts or
uterus. Each egg was enveloped in two delicate colourless
tunics. The last egg contained a granular matter, equally
divided, which filled out the greatest part of the tunics. I
could perceive here no germ ; it had, perhaps, retired to the
middle of the yolk. If you examined the eggs in the uterus
which are situated more in the upper part, you find that the
granules of yolk matter come nearer to one another, and that
they at present do not occupy the whole space of the coverings.
Still more anteriorly the granular matter in the eggs begins
to separate into several round heaps, which hang closely
together under one another, and give the form of the yolk a
somewhat ragged appearance. In the interior of each of these
granular heaps a clear bright spot was to be seen. Such was
the state of the eggs to the uppermost end of the two horns of
the uterus. After both horns had united into one canal, this had
become, 4th, The vagina, and so narrow that no more than one
egg at a time could slide through it. This vagina ended after
a small bend into the slit towards the outside, and emitted
eggs in my presence.

If we now return to the vessels of the male branch, it might
occur to us that the vessel described is the seed vessel, and the
two long hard substances the double penis. Truly I am indeed
here not able to say in what connection the excretory organs
of the testis stands to the female generative organs, whether
both possess one opening, or have both different ones, each of
which opens externally.

♦ I have already in this Archiv, (I. 1, p. 79.) made observations on this
germ in the Nematoidea : since then I iiave seen it quite distinctly in Spi-
roptera contorta, Ascaris vesicularisy lumbricdides, ensicaudata^ aucta, and in
Trichocephcdus unguiculatus ; in the last I perceive it even in the ovarium
before the yolk was covered with shell. On the contrary, it appears to be
more and more confirmed that this bladder is wanting in the eggs of the
Acanthocephaluy Trematodny and Cestoidea. Up to the present time t
have found no trace of the same in the eggs of the intestinal worms belong-
ing to these orders. Wagner also did not perceive it in T(snia and Disto-
rnum. (See Miiller's Archiv, II. 4, p. 375.)

the Syngamus trachealis. 259

On the nervous, vascular systems, &c., I can state nothing,
nor do I intend to say that my description of this worm can
be called complete; this I hope will be pardoned on account
of its rarity, which was the reason that 1 could not give a bet-
ter description of it. Perhaps I shall be able at a future time
to examine it more thoroughly. The main thing was not to
keep this remarkable parasite longer from the friends of hel-
minthology. It is certain that the same worm may be disco-
vered in many other birds, although it is rather curious that
three so very different birds as the woodpecker, the swallow,
and the hen, should be infested by the same intestinal worm.
It belongs therefore to those parasites which are diffused in the
same classes of animals, as is the case in Distomum hepaticum,
lanceolatum^^ and ovatum\^ &c. That the l^i/ngamus trachealis
forms quite a new genus of intestinal worms will be clear to
every one. By the name Syngamus I thought to signify the
combination of a male and female individual in one animal.
The connection of two individuals of different sex is here also
combined with the circumstance that both parts remain much
more individualized, as each possesses an intestinal canal,
while, in Diplozoon^ both androgynal halves have one and
the same canal J.

If we seek a place in the system for Si/ngamus, we find our-
selves at a loss, as it comes into none of the five known orders.
I am, however, sure that even in a better system there would
be a difficulty in placing it, on account of its remarkable pro-
perties. If we consider the male and female parts each alone,
we find they have a great resemblance in their form and struc-
ture to the Nematoidea. The body is protended and cylindri-
cal ; the intestine is simple, and possesses a muscular cesopha-
gus, which is also protended ; the generative organs have the
same appearance as in many of the Nematoidea. The uterus,
ovary, &c., are double, as in Ascaris, Spiroptera, Strongylus,
and others §. The ovaries are not branched like those of the

* Some time ago I found the gall-bladder and gall-vessels of the liver in
a young cat filled with many hundreds of this Distomum.

t The Distonmm ovatum, which till at present was known as only inha-
biting the bursa Fabricii of the Corviis Comix, frugilegus, Fica, of the Anas
cli/peata and Fulica, (see Rudolphi*s Synopsis, p. 93,) I have found in the
same organ also of Falco Subbuteo,Corvus glandanus,Corvus Moiiedula, Turdus
viscivoruSf Hirundo tirhica. Partis major, Crcx pratensis, Gallinula Porzana,
ChloropuSy Una Troile, and Phasianus Gallus. I also found it several times
of enormous size even in the white of hen's eggs. The place of this parasite
seems to be supplied in sea birds by Holostom. platyccphalum, which Creplin
(in Observat. de Entozois, p. 39,) has described at first from Colymbus rufo-
gularisy and which I have taken from a doubtful organ of Larm canus,
fuscus, Halieus Carbo, Colymbus septentrionalisy and Falco AlbiciUa.

X Nordmann's Memoirs, I. p. 67.

§ Trichosoma and Trichocephalus have only a simple uterus and a simple
ovarium.

2L2

9:60 Dr. Von Siebold on a Double-bodied Intestinal Worm,

Trematoda^ but simple and manifold tortuous canals, like
those we find in all the ISlematoidea. The testis with its bi-
furcate penis, according to its structure, coincides with the
male generative organs of the cylindrical worms. Further,
the generative organs lying together with the Intestinal canal in
one cavity of the body forms another character which belongs
to the parasites of the first order. It was only the blind end
of the intestinal canal, and the want of rings on the skin, which
could cause any difficulty as to its being placed among the
Nematoidea; much less its wide mouth, which, as before re-
marked, has more resemblance to the basin-like sucker of the
Trematoda, yet not formed of a muscular, but of a horny sub-
stance. Several species of Strongylus show the same. The
two before-mentioned basin-formed mouths may have misled
Montagu, as he classed this animal with ihe Fasciola; and
having given the mouth as being divided into six parts, Ru-
dolphi thought proper to place it by the side of Distomum
linea7'c {poro aiitico nodulis sex cincto), as he supposed the
male neck with its mouth-opening to be a petiolated porus
posticus. Thus considered, this worm could not acquire the
interest which properly belongs to it; as at the same time a
true double-branched Distomum. could be placed by its side ; I
mean Distomum fur catum ^.

I take leave, in conclusion, to call attention to the following
comparisons, which, in the examination of this worm, after
having learnt its true structure, forced themselves on me, with-
out intending to lay value on them. In all round worms the
males are shorter than the females. In Syng. trachealis the
male portion is by far much shorter than the female. In the
male worms the caudal extremity, where the generative or-
gans always terminate, always joins at the pairing-time with
the body of the female, forming an acute angle t- Bearing
this in mind, we have the following transition to our mon-
strous form. Both sexes of almost all cylindrical worms unite
only at the pairing-time. The male of the Hedruris andro-
jphoraX has the habit at other times also of embracing its

* Riidolphi, Synopsis, p. 107, No. 72j and Bremser, IconeSy tab. ix.
figg.13,14.

■j- See in Bremser, Icones^ tab. iii. figg. 8, 15; and Giirlt, Lehrbuch der
Patholog. Anatomie der Haus-Saitgethiere, tab. vi. fig. 35.

X Nitzsch, in Ersch and Gruber's Encyclopaedia, Th. vi. p. 49, and Th.
ix., 3rd taf., fig. 7; hIso in Schmal, Tahulce Jnatomiam JEntozoorum i/lustr.,
tab. xvii., fig. 5. Nitzsch observed (p. 49,) at the margin of the caudal
socket of the female, a small arm which he thought to be the undeveloped
tail end. I have satisfied myself that this arm is of a horny nature, and that,
as it enters into the ir)embrane of the stomach, it serves as a firm hold for
the female worm. The place on which the animal fixes itself is also per-
ceivable on the outer side of the stomach by a tuberculous projection.

Prof. Forbes on the Ascent of Moim tains. 261

female; here also a continued junction of both jj^enders with-
out being grown together, and in Syngamus trachealis a con-
tinual combination, by being really grown together.

Explanation of the Figures {Plate L),^

Fig. 5. Syngamus trachealis, natural size.

Fig. 6. The same (another specimen, with much longer male
branch) greatly magnified, a. Male branch, b. Fe-
male branch, c. Incision into which the generati ve
organs descend.

LI I. On the Muscular Effort required to ascend Planes of

different Inclinations. By Professor FoRBES.f
TT has been long pretty generally knoWn that the same ex-
■^ pense of muscular energy will carry a person through
nearly the same vertical height in a given time, at all angles
of elevation not very small. At least we find writers on the
subject of strength, measuring effort by the number of pounds
raised multiplied into the height attained. I am persuaded
that this is much more rigorously true than is usually sup-
posed, and that a person in uniform health and of a* good
habit of body will ascend through almost precisely the same
number of vertical feet in an hour (unloaded) whether the
ascent be rapid and short, or tortuous and little inclined, ex-
cluding, of course, extreme cases.

All paths by which mountains are usually ascended on
foot, lie within these practical limits; the mean angle of
ascent on footpaths varying in different cases from 10° to^S"^,
seldom being below the former, and almost never exceeding
the latter. In fact, the angle of ascent is determined, not so
much by the configuration of the ground as by the instinctive
(or rather experimental) modification which the walker gives
to it by such zigzag courses as increase the length and dimi-
nish the steepness of the path. This makes the difference of
ascent less than might at first be supposed. Thus the time
required to ascend a mountain whose height is known, may
be pretty accurately predicted by any individual who has de-
termined the measure of his muscular energy ; and conversely,
heights maybe deduced from the times of ascent with surpris-
ing accuracy, a result of great use when more exact methods
cannot be employed.

From the observation of Borda upon the men who accom-
panied him in ascending the Peak of Teneriffe, the ascensional
effort was 1225 English feet per hour, continued for eight

* The Plate was given in the Number for March.
t Communicated by the Author.

262 Prof. Forbes on the Muscular Effort required

hours in a day. This estimate does notdifler much from that
of the guides at Chamouni. My own experience would give
results somewhat greater, and the constant must of course be
determined by each individual for himself. For heights not
exceeding 5000 or 6000 feet I find 1500 feet per hour to cor-
respond to the most moderate sustained muscular effort, and
which might be long kept up ; the only kind of observation of
any value, since excessive exertion puts all calculation at de-
fiance.

1 long since proposed to myself to find an expression for
muscular exertion in walking which should mclude inclined
planes of all inclinations, and consequently a horizonal road
as a particular case, where the preceding reasoning becomes
inapplicable, since the distance corresponding to a given
height is infinite. During the prosecution of experiments at
great elevations already partly before the Royal Society of
Edinburgh, I have had an opportunity of extensively consi-
dering this practical question. My practice when in Switzer-
land in 1832, was to measure from time to time the inclination
of the path with a kiinometer, and to note the times elapsed,
making observations when necessary for the total height with
the barometer. The continued and equable ascent of some of
the carriage passes of the Alps afforded a good opportunity of
observing at small inclinations when the horizontal component
became relatively great, whilst long experience gave me per-
fect confidence in the uniformity with which I walked day
after day, at the rate of four miles an hour, on level ground.
These experiments seem to indicate about 700 vertical feet of
ascent per hour at an angle of 3j°, from 1000 to 1100 feet
at 7°, and nearly 1500 feet per hour from 10° to 20°, without
much variation, but rather indicating that the higher angles
were the more advantageous.

For inclinations greater than 25°, there is a deficiency of
directly comparable observations. Coulomb could not per-
suade a labourer to ascend a stair cut in the rock, through a
height of 9000 feet in a day, at the usual wages. The angle
may be supposed equal to 30° or 35°. This may be consi-
dered to indicate a diminution of useful effect, and confirm
the existence of a maximum advantage between 20° and i)0°.

At very high angles the tread-mill affords some curious re-
sults. It appears from the statistical tables* that though the
velocity of tread-wheels varies much, as well as the total work
done in a day, yet there is more uniformity in the hourly

• See Parliamentary Reports, and particularly Prison Discipline Society's
Report for 1823.

to ascend Planes of different Inclinations, 263

vertical ascent than might be expected. The reliefs being
more frequent when the velocity is great, the work done varies
in summer and winter, but may generally be stated at from
1400 feet per hour.

The most remarkable circumstance is the high angle of
elevation at which this effort is performed, and which I doubt
not might be advantageously modified if ceconomy of the la-
bour of prisoners should ever become an object. I have ex-
amined the operation of the tread-wheel in Edinburgh, and
find that the angle of ascent is about 80°, and sometimes al-
most vertical. It is not to be supposed that this angle is as
favourable as a smaller one, though the work done is greater
than in some cases already considered ; this being a punish-
ment and considered as hard labour, the other (the ascent of
mountains) being only equivalent to an active man's common
daily work. The viev/ in making the angle of ascent of tread-
wheels so great is, no doubt, to secure the greatest effective
leverage of the man's weight; but by duly increasing the ra-
dius this leverage might be attained at any other angle, and
the stepping-boards instead of being prolongations of the
radii should form an angle with them such as to make them
horizontal at the part of the wheel where the moving power is
applied, which should be when the radius forms an angle
perhaps not greater than 40° with the vertical.

The tread-wheel observations are the most satisfactory at
high angles, since when ladders are used (as in the Cornish
mines, and those which communicate with the village of AI-
binen near Leuk in the Valais.) powerful assistance is afforded
by the arms.

In the want of decisive observations, we shall assume 1100
feet per hour as the ascensional effort at the extremity of the
scale when the ascent is vertical, or the horizontal component
null; being somewhat more than two thirds of the maximum
effect. This must be considered, however, as in some mea-
sure conjectural, and to be corrected by future experience.
I would also add, that it is distinctly to be kept in view that
the effort which we mean to represent is not an extraordinary
but an ordinary due ; not what by a certain degree of exertion
might be accomplished for a single day, much less the maxi-
mum effect attainable, but an amount of labour which may be
continued for eight hours aday at least, and for many days
together *.

Since we propose to include in a formula both distance and

* As an example of the necessity of attending to this, and also of the
usual method o^ observing, I quote my observations during the ascent of
the Rigi, a hill of comparatively small height, and particularly accessible :

264 Prof. Forbes on the Ascent of Mountains.

height, as they respectively exhaust muscular power, that
empirical formula ought to be such a function of a, the angle
of inclination, that, 1, When a = 0, the distance shall be
four miles nearly, and the height ascended in an hour = 0;
2, When a = 90°, the height ascended, or distance x sine a,
shall be = 1000 feet neatly; 3, When « is between 20° and
30°, the ascensional effort or dist. xsin a shall be a maximum,
and = 1500 feet nearly; 4, That it shall vary slowly be-
tween 10° and 30°, and that below 10° it shall adapt itself
nearly to the experiments.
Now, a formula of this kind.

= \ -' — ; 7^ — 6 sin a y sin a,

\sm(a + fl) j '

sufficiently well satisfies these conditions ; h being the vertical
height in English feet attained in an hour, a and d being con-
stants, and 6 a constant angle. It will at once be seen that
the part within brackets measure.^ the distance traversed, and
determines the very rapid rate of diminution of the expression
for the first degrees ; a fixes the horizontal distance passed
over in an hour, and b the diminution of ascensional power
when the inclination is nearly vertical. Should this diminu-
tion be much smaller than we have supposed, the second term
might be independent of a, and should the maximum effect
be at a vertical inclination (which however is most impro-
bable) it would disappear altogether. The following numbers
seem best to satisfy my experiments :

h = < - — 7 r^rr — 800 sin a > sin a in English feet.

The following table exhibits the results of this law:

A" (t1 f a t Space described Height ascended
ng seen . -^ ^^ hour. in an hour.

feet.

0°

21800 feet.

0

5

10872

948

10

7202

1251

15

5348

1384

20

4198

1436

25

3462

1463

30

2913

1456

50

1706

1307

70

1215

1142

90

1107

1107

the result it will be seen is greatly above the mean effect. " 1832. Oct 15.
Left Weggis 2^ 5"". Angles of ascent i)^ . 15°, 15°, 8°, 1 1°, 16°, 1 1°, 15°,
2°, 12°. Mean ll°-4 Rigi— Culm. 4^ .35"'" The height is 4400 English
or at the rate of about 1800 feet per hour.

[ 265 ]

LIII. On the Aurora Borealis of February ISi/i^ 1837, as oh-
served at Sidmoitth, in Devonshire. By N. S. Heineken, Esq.

To the Editors of the Philosophical Magazine and Journal.

GeNTLExMEN,

T^HINKING that some of your readers may feel an interest
-■• in a subject which is becoming of much importance in
meteorology, I am induced to forward, for insertion in the
Philosophical Magazine, the following account of some ob-
servations which I made during the occurrence of the most
splendid aurora borealis which 1 have ever witnessed.
I am, Gentlemen, respectfully yours,

N. S. Heineken.

At 16™ past 7 (mean time), in the eveninf^g of the 18th of Fe-
bruary (Saturday), I observed the commencement of an aurora
borealis of the most vivid pink hue, occasionally approaching
to scarlet. At this time the centre of the brightest part of the
aurora bore, by compass, about 6° north of west, allowance
being made for variation. At 27"* past 7 the bearing con-
tinued nearly the same. The altitude of the upper edge (which
was not well defined), taken, as near as might be, at the time
with a Gunter's <]uadrant, and verified afterwards with a re-
flecting sextant, was about 55°. At 32™ past 7 the former bear-
ing of the main body continued the same, but the tint had
now spread round to the N.E. The altitude of the brightest
part was from 35° to 36°, the altitude of the edge remaining
much as before. The stars in Cassiopeia shone through the
aurora (though not the most brilliant part of it) somewhat
more dimly than usual, and they appeared to partake of the
colour also, as did other stars. The thermometer stood now
at 434°, the barometer at 29*566. The smallest lock of white
cloud (cirrus?) passed over at 3"^ before 8 to the eastward :
at 15"^ past 8 fleecy clouds arose from the very point of the
ai.iora's first appearance and passed to the eastward. The
gold leaves of the electrometer were no^ slightly, but evidently
affected. 1 mention this latter circumstance (which I ob-
served again in the course of the evening) with some hesita-
tion, finding that upon several occasions in the Polar expedi-
tions no such indications were given. The wind, I may men-
tion, was now very moderate. About 9"^ before 9 the aurora
shifted to S.S.W.; a slight pink band appeared between
Rigel and Sirius ; an arch was formed of the same colour at
1™ before 9, edges not well defined, passing between Aldebaran
and >3 Orionis, over Castor and Pollux, and extending a little
beyond diem on either side, and, still continuing, the western-

Third Seiies. Vol. 10. No. 61. April 1837. 2 M

266 Mr. Heineken 07i the Aurora Borealis of Feb. ISth, 1837-

most edge was bounded by /3 and y Ursae Majoris. The arch
appeared to arise from a mass of vivid pink light, but ob-
stacles prevented me from seeing the terminations. Arch
again visible at 4™ past 9, nearly as before. At 1 2"" past 9 the
thermometer had fallen to 41° and the air was sensibly cooler;
several faint white streamers shot up in magnetic north ; no
appearance at 17"" before 10. A most splendid arch at 8"^
past 10 passing between >] Orionis and Aldebaran ; one edge
bounded nearly by Castor, and the other by s and y Ursap.
Majoris. Upon going indoors to an upper window I could see
this magnificent arch, more glorious even than the arch of
promise, terminated on each side by the hills between which
Sidmouth is situated, and attaining an altitude of, I should
suppose, betweerf 80° and 90°. At each termination the mass
of light was wider, at least twice the width of the higher parts
of the arch, and in that to the eastward I observed two or
three well-defined dark vertical spaces or bands. At IS'" 30^
past 10 several white streamers, which I could not discern
out of the arch, shot across it from the western side near
Capella. The streamers, which had the appearance of white
bands, made by rough estimation an angle of 60° or 65° with
the western edge of the arch. At ll'" before 11 patches
of irregular full pink light had taken the place of the arch; a
large brilliant mass being over Ursa Major, and to the south-
ward of it. Many fleecy clouds again arose from the point
of the aurora's first appearance. The only meteor which I
observed during the evening was at 20'' past 11, brilliant, but
not large. It appeared (by estimation) about 2° SO' above
Capella; extent, of course to the north-westward, 5° or 6° : du-
ration little more than a second, leaving no train. After this
period the aurora became fainter, and finally ceased.

I may observe that the day had been stormy, with heavy
showers, the wind in squalls from S.S.W. A short time
before the appearance of the aurora the wind lulled, and, ex-
cept during the times I have noted as cloudy, the moon
was shining brilliantly during the whole of this, notwithstand-
ing, most splendid spectacle. I had thus also afforded to me
an opportunity of correcting my watch by observing the oc-
cultation of Mars. I have to regret that I had not completed
a needle for magnetic observations. I subjoin, however, the
state of the thermometer and barometer on the morning and
evening of the 18th and 19th.

A.M. 9 o'clock.

10 P.M.

Therm.

Max. Min.

Bar.

Therm. Bar.

18th. 50 42

29-768

40 29-610

19th. 48i 37i

29-480

49| 29-068

Dr. Schoenbein on the peculiar Voltaic Condition of Iron. 267

damp — showers; and until today (25th) the weather has been
very stormy, with heavy wind, rain, and hail.
Sidmouth, February 25, 1837.

P.S. In the Magazine for last month, (January,) p. 75,
Mr. Mallet has mentioned the occurrence of an aurora on the
evening of October 5th, 1836. May I be allowed to state, that
at about 7 o'clock on that night I observed, at Sidmouth, a
patch of faint pink light partly over U. Major, but there was
no further appearance of aurora here?

LIV. Experimental Researches on a peculiar Action of Iron
upon Solutions of some Metallic Salts. By Dr. C. F. Schcen-

BEIN.*

COME time ago I published several papers f, in which I
^ made known some very remarkable facts regarding the
action of iron upon oxygen. According to the notions ge-
nerally adopted by philosophers respecting the action of metals
performing the function of the positive electrode upon oxy-
gen set free by voltaic action, iron, as one of the more readily
oxidable metals, chemically combines with that element. In
one of the papers alluded to, I have shown that these notions
with regard to iron do not hold good in all cases, and that
this metal acquires under certain circumstances the property
of platina or gold, that is to say, that whilst constituting the
positive electrode, it is neither oxidized nor otherwise cliemi-
cally affected by oxyacid solutions, which usually act upon
iron with more or less violence. 1 have further observed, that
this inactivity of iron depends upon the manner of closing the
circuit, as well as upon the chemical nature of the electrolytes
contained in the solutions in which the polar wires of the
pile are immersed. Solutions containing oxyelectrolytes which
act chemically upon iron, as, for instance, sulphuric or nitric
acid, require the circuit to be closed in a certain manner in
order to evolve ox^^gen at the positive iron. Solutions con-
taining oxyelectrolytes which do not sensibly act upon iron,
as, for instance, those of potash, soda, and a great many oxy-
salts, allow the evolution of oxygen at the positive iron quite
independently of the manner of closing the circuit. In solu-
tions containing, besides oxyelectrolytes, others of a different
nature, for instance, hydracids, haloid salts, &c., no evolution
of oxygen takes place in whatever manner the circuit may be
closed. From these facts, and others stated elsewhere, I am

* Communicated by the Author, through Mr. Faraday.
t See Lond. and Edinb. Phil Mag., vol. ix. pp. 53, 122, 259; and present
volume, p. 133, 172. — Edit.

2 M 2

268 Dr. SclicEiibein's Experimental Researches on a peculiar

inclined to infer that the affinity of iron for oxygen is de-
stroyed by a current moving through tlie metal in a certain
direction, and that the affinity lost in this way by the iron is
revived by an opposite current. To ascertain whether this
view holds good generally with regard to iron, I have made
a series of experiments, the results of which are as follows.
I introduced an iron wire which had previously been con-
nected with the positive pole of a small battery, into an aqueous
solution of the common sulphate of copper, by means of which
the circuit was closed. According to my hypothesis no ac-
tion whatever is to take place on the part of the iron upon the
solution, under the circumstances here stated. My expectations
were fully realized, for after many hours' action of the pile
not the smallest particle of copper was deposited on the iron
wire, its surface had not undergone the least change, and du-
ring the whole time of action oxygen was evolved at the iron.
But as soon as the passage of the current through this metal
was opposed only for a moment, for instance, by taking out
of the copper solution either the. negative polar wire or the
positive one, there appeared on the surface of the latter a film
of copper. (The same result was obtained by joining momen-
tarily the two polar wires within the solution, or by touching
the iron wire with another metal capable of precipitating cop-
per.)

Now, by these facts I think two things are clearly shown,
first, that iron ceases to have any affinity for the oxygen both
of the oxide of copper and of the water decomposed by voltaic
action, and secondly, that this state of chemical indifference
lasts only so long as there is a current passing from the iron
into the copper solution. This influence of current electri-
city upon the chemical bearings of iron is highly interesting,
not only on account of its being contrary to the electro-che-
mical notions hitherto entertained on the subject, but also on
account of the circumstances under which the oxygen result-
ing from the decomposition of water is presented to iron.
These circumstances are, indeed, of such a kind as highly to
favour the oxidation of the metal, for oxygen in a nascent
state is brought into contact with iron, and there is at the same
time a portion of the acid of the salt set free by voltaic action
at the iron wire, which also tends to occasion the oxida-
tion of the latter. The same remarks apply to the fact al-
ready stated, that iron is not acted upon by nitric or any other
oxyacid, provided this metal is placed under the influence of
the pile in the manner above mentioned. Iron, however,
may acquire the property of being not acted upon by nitric
acid or solutions of certain metallic salts without being sub-

Action of Iron upon Solutions of some Metallic Salts, 2G9

jected to the influence of a current. This remarkable fact has
been observed by Sir John Herschel, and more recently by
Mr. Faraday and myself. IT, for instance, a common iron
wire, having been made inactive by repeated immersions in
common nitric acid, is put into a solution of blue copper vitriol,
not the least chemical action takes place. It is true that it
happens sometimes that such a wire precipitates copper at
the moment of its being plunged into the solution, but in such
a case the inactive state of the metal had ceased previously to
immersion. Now whether iron is or is not in its peculiar con-
dition may easily be ascertained by the appearance of the
surface of that part of the wire which had been immersed in
nitric acid. If the surface is bright, the wire is inactive; if
yellowish brown, the metal has assumefl its common state,
and will consequently act upon the copper solution in the
usual manner. The peculiar condition of iron with regard to
the copper solution can be destroyed in different ways. In
the first place it may be destroyed by making an inactive iron
vibrate. If such a wire is wetted by the said solution, and
afterwards rather violently struck against any solid body, for
instance against a table, immediately after the shock a film of
copper will make its appearance along the whole wetted sur-
face of the wire *. According to the results of my experiments,
published in several periodical works, inactive iron is rendered
active with regard to nitric acid by the same means. In the
second place the active state of iron may be reproduced by
touching the inactive metal with a metal which acts chemically
upon the solution of the copper salt. If an inactive wire is
whetted by this solution, and then touched, on any point of the
part wetted, with a piece of common iron, zinc, cadmium, tin,
lead, arsenic, or even copper, the precipitation of copper in-
stantaneously takes place at the point of the iron wire where
contact had been effected, and this action rapidly extends itself
over the whole part of the wire which is covered with the so-
lution. It is a matter of course that the same effect can be
obtained by touching the inactive iron wire within the solu-
tion of the copper salt with the same metals. But the pecu-
liar condition of iron may be changed into the common state
without immediately touching those parts of the metal which
are surrounded with the copper solution. If, for instance, an
inactive wire is put into the solution so as to allow part of it
to rise above the level of the fluid, and if a wire of any of the

• This remarkable fact, considered by itself at least, tends to confirm
Prof. Faraday's impression as to the cause of the peculiar voltaic state of
iron. — Edit.

270 Dr. Schcenbein*s Experimental Researches on a peculiar

metals above mentioned is placed in the same solution, hav-
ing likewise one of its ends raised above the surface of the
liquid, copper will be precipitated as soon as the free ends
of both wires are made to touch one another. This mode of
changing the state of iron is exactly the same as that by which
a similar change of condition of this metal may be effected
with regard to nitric acid. Now, all these facts evidently prove
that the peculiar condition of iron, whatever the cause of it
may be, is always destroyed by the chemical action of metals
brought into contact with iron when in the inactive state.
There is certainly one singular fact, which seems to indicate
as if contact independently of and unconnected with chemical
action could of itself occasion a change of state in iron. It
has been already stated, that copper brought in some of the
ways mentioned into contact with an inactive iron wire, which
is immersed in the copper solution, renders the latter metal
active. Now copper of course cannot be precipitated from
the solution of blue vitriol by copper; the chemical action of
this metal upon the copper salt must, therefore, be essentially
different from that which is exercised by the more readily
oxidable metallic bodies in question. First, I thought there
might, perhaps, be some free acid contained in the solution,
and by this means chemical action occasioned. To ascer-
tain the correctness of this view, I added ammonia to the
solution until flakes of oxide of copper were beginning to
make their appearance ; but the copper wire acted in such
a neutral solution in the same manner as it did in the more
acid one ; chemical action consequently does not result from
the cause supposed. I think there is only one way left to ac-
count for the fact in question. It is well known that copper
put into a solution of a salt containing the deutoxide of this
metal, unites by degrees with this base, to form protoxide of
copper. Although this chemical action is extremely slow
and weak, still it is of sufficient power to revive in the inactive
iron its dormant affinity for oxygen.

There is no doubt that, one case excepted, in all others
hitherto mentioned, in which passive iron is rendered ac-
tive, an electric current is produced, passing from the metal in
which chemical action originates, through the solution, into
the inactive iron, and from this back again to the first me-
tal. It is further obvious, that the direction of the current
passing through the inactive iron is opposite to that in which
the current moves through an iron wire which performs the
function of the positive electrode of a pile. The chemical
effects produced upon iron by these different currents being
also the reverse of one another, it seems to me that these facts

Aciion of Iron upon Solutions of some Met dlic Salts. 271

speak in favour of the idea already suggested that the che-
mical affinity of iron for oxygen is destroyed by one kind of
current, and called forth again by the other. It is true, one
of the most sagacious philosophers of the age, Mr. Faraday,
has started an idea which seems to account very satisfactorily
for the phiienomena in question. According to his view the
peculiar condition of iron depends either upon a film of oxide
covering the metal, or upon a relation of oxygen to iron equi-
valent to oxidation, so that the particles forming the surface
of the inactive iron have satisfied in one way or other their affi-
nity for oxygen. Applying the same hypothesis to account
for the bearing of iron in the solution of blue vitriol which
Mr. Faraday has made use of for explaining the singular ac-
tion of iron upon nitric acid, we must s^y, an inactive iron
wire does not act upon the solution of the copper salt, because
there is no immediate contact between the truly metallic par-
ticles of the wire and the said solution, on account of the in-
terposing film of oxide, or something similar to it. But if
now another metal be put into the solution, which is chemically
acted upon by the latter, there is a current produced, pro-
ceeding from the active metal, and passing through the solu-
tion into the inactive iron. By this current water is decom-
posed, hydrogen evolved at the iron ; the film, or what is equi-
valent to it, deprived of its oxygen; and by this means a truly
metallic surface of the iron wire produced. Though this
way of accounting for the facts in question recommends itself
by its beautiful simplicity, and what is still more valuable by
the great advantage of bringing back an apparently anomalous
case to a general law, still there are weighty reasons stated
by me elsewhere, which will hardly allow the adoption of
Mr. Faraday's sagacious hypothesis.

After having examined the action of iron upon the common
sulphate of copper, I was curious to see how the same metal
acts under similar circumstances upon the solutions of the
nitrates of mercury. Before entering into details upon the
subject, I must not omit to state, that I did not observe any
essential difference of action between the protonitrate and
pernitrate of mercury. A common iron wire, cleaned or not,
when put into a solution of either of the neutral nitrates of
mercury, does not act in the least upon the salt, that is to say,
no mercury is precipitated on the iron ; but what is still more
surprising, the iron wire, after having been immersed only for
a few seconds in such a solution, shows all the properties of
inactive iron ; it will, for instance, not be acted upon by com-
mon nitric acid, nor by a solution of blue vitriol. Even when
a strong solution of the mercurial salt is diluted with 1000

272 Dr. Schoenbein*s Experimental llesearches ofi a peculiar

times its volume of water, it will still render an iron wire in-
active, though in this case, as might be expected, some time
is required for obtaining the effect. But if a common iron
wire is first immersed in water containing so little of nitric acid
as scarcely to change the colour of blue litmus paper, and af-
terwards plunged into the solution of mercury, it will preci-
pitate the latter metal. It is, indeed, quite extraordinary how
far this influence of the acids, favouring metallic precipita-
tion, extends. I mixed a strong solution of neutral proto-
nitrate of mercury with 1000 times its volume of water, and
in the same proportion I diluted common nitric acid. By
putting the wire first into the acidulated water, it always
acquired the property of decomposing the diluted solution
of mercury on being plunged into it. Common muriatic
acid, even 4000 times diluted with water, produced the same
effect. Though it is a well-known fact that some free acid
contained in metallic solutions favours the precipitation of one
metal by another, still I am not aware that any chemist has
as yet stated any particulars regarding the extent and cause
of this ir lu-iice. The peculiar action of acids mentioned
seems to be intims'ely connected with the subject of my re-
searches on the ac'i n of iron upon nitric acid, and to afford
a case similar to that presented by inactive iron in its bearing
to strongly diluted nitric acid. In one of my published papers
on the subject, I have stated that inactive iron loses its pe-
culiar cond'tion by being put into diluted nitric acid; the
same thing takes place in the case before mentioned. Com-
mon iron wire is of itself inactive in a solution of a neutral
salt of mercury, but is rendered active by being subjected to the
action of acidulated water previously to its immersion in the
solution. According to Mr. Faraday's views the acid must
produce the effect spoken of by cleaning the surface of the
wire, that is to say, by dissolving some film, with which even
a common wire must be supposed to be covered ; but for
reasons already alluded to, 1 cannot entertain the opinion of
this distinguished philosopher, even in this case.

The view I have taken of the subject leads me to ascribe
the effect in question to chemical excitement in the metal
occasioned by the acidulated water. As iron having only for
a few moments been immersed in diluted acid decomposes the
neutral solution of mercury, it might 'be supposed that this
metal should act in the same manner in a solution made some-
what acid. But I found this not to be the case. A solution
of pernitrate of mercury obtained by saturating nitric acid,
sp. gr. 1*35, with peroxide of mercury, was mixed with its
own volume of the same acid. A common iron wire put into

Action of Iron upon Solutions of some Metallic Salts, 273

this acid solution had no action upon it, and assumed its pe-
culiar condition. I could put even twenty volumes of nitric
acid to it, without producing any action. But I must not omit
to state the singular fact, that there is in this respect a great
difference between a wire flhich is cleaned and one which is
not. If, for instance, a common iron wire has only once passed
through a piece of linen or cloth, it will be acted upon by the
acid solution containing only one volume of nitric acid, whilst
an uncleaned one is not affected at all. This difference is the
more remarkable, as an uncleaned wire is much more violently
attacked by mere nitric acid than a clean one. Another fact,
still more singular, is, that different parts of the same piece of
an uncleaned wire are sometimes differently acted upon by the
same acid solution of mercury, one part being, for instance,
entirely inactive, whilst another contiguous to it proves to be
highly active. I call this fact a very singular one, because
every bit of a whole roll of iron wire is acted upon in common
nitric acid. When an iron wire cleaned or not is plunged into
the solution of mercury containing from 30 to 50 times its vo-
lume of nitric acid, it will be affected, and continue to be acted
upon if left in the solution ; but when it is again taken out of
the fluid and held for hardly a second in the air, after its re-
immersion it will prove entirely inactive. It is surprising,
that almost the same results are obtained at very different
degrees of temperature. I heated a mixture containing 20
volumes of nitric acid and one volume of the solution of per-
nitrate of mercury to its boiling-point. The end of an iron
wire put into it was certainly acted upon, but by withdrawing
it only for a few moments from the solution it was rendered
inactive, so that it could afterwards be reimmersed in the
nearly boiling acid fluid without being attacked by it. A cer-
tain proof that the metal acquires, even at this high degree of
temperature, its peculiar inactive state is, that when put into
a solution of blue vitriol, or into mere common nitric acid, it
does not in the least act upon these substances. In making
these experiments I frequently observed the curious fact, that
the iron wire immersed in the nearly boiling acid solution
loses its inactive condition as soon as it is a little raised so
as to expose to the air a very small part of that portion of
wire which has been immersed in the fluid ; but though this
is often the case, it is not invariably so.

The results which I have obtained from experiments made
with iron wire and an acid solution of mercury much diluted
by water, are likewise worthy of being stated. One volume of
a very strong solution of neutral protonitrate of mercury, five

Third Series. Vol. 10. No. 61. April 1837. 2 N

274- Dr. Scbcenbeiii's Experimental Researches on a peculiar

volumes of nitric acid, sp. gr. 1-35, and 200 volumes of water
were mixed together. A piece of cleaned iron wire put into
this solution did not precipitate mercury. By plunging such a
wire into water slightly acidulated, its power of acting upon the
salt of mercury, as above mentioned, is instantaneously called
forth. The wire having once acquired this power retains it;
provided, however, it be called into play at intervals of time
not much exceeding a second or so. But if the wire after
having been active in the solution is taken out of it, cleaned
from the adhering mercury, and Itjft exposed to the air only
for a ^evf seconds, it will have lost its property of precipitating
the last-named metal, and rest entirely inactive in the solution,
whatever length of time it may remain immersed in it. This
remarkable and sudden change of the condition of iron is most
likely due to some action of the air; for if the wire, being still
in its active state with regard to the solution of mercury, is
put into water or hydrogen gas, it preserves its precipitating
power. I have not yet put iron into other mediums than those
mentioned, nor have I examined whether moisture has any-
thing to do with the phaenomenon. At any rate this subject
seems to me in many respects sufficiently interesting to de-
serve further investigation. Before passing to another sub-
ject, I have still to mention some facts connected with those
just spoken of. An iron wire which proves to be entirely
inactive in the last-mentioned solution of mercury, is not so
with regard to a solution of blue vitriol or to common nitric
acid ; for a wire which does net throw down mercury, pre-
cipitates copper, or is violently acted upon by the said acid.
From chemical reasons we are led to expect that the very
contrary should take place, the affinity of copper Tor oxygen
being much greater than that of mercury; that is to say,
we should think the mercury salt easier to be decomposed by
iron than the copper Salt. It seems, therefore, as if the ano-
malous fact does not result from the action of common affinity.
Another fact worthy of remark is, that iron acts quite differ-
ently upon the neutral nitrates of mercury dissolved in al-
cohol or aether, from what it does upon the aqueous solutions
of the same salts. In the former case iron always precipitates
mercury and never turns inactive, whilst, as above stated, in
the latter case the contrary takes place. If an iron wire, hav-
ing been rendered inactive by immersion in an aqueous solu-
tion of the mercury salt, is put into alcohol or aether con-
taining the same salt, it loses its peculiar condition and re-
turns into its active state.

I think it not quite irrelevant to the subject treated of in this

Action of Iron upon Solutions of some Metallic Salts, 275

paper, if I produce a new case bearing evidence in favour of
the theory*, according to which voltaic electricity is due to
chemical action. It is true that the beautiful researches of
Mr. Faraday, as well as those of Mr. De la Rive, have led to
results which remove from an unbiassed mind even the shadow
of a doubt on the subject, and which prove in the most satis-
factory manner, that mere contact of heterogeneous metals is
not capable of disturbing their electric equilibrium. Still,
as the number of philosophers is as yet rather considerable
who maintain the hypothesis of Volta, I think it not quite
useless to increase the body of evidence against it.

If an iron wire rendered inactive by immersion in nitric acid
is associated with a platina wire, and two of their ends put
into a solution of blue vitriol, not the siiiallest quantity of
copper will be precipitated on the platina ; but if the inactive
iron is thrown into chemical action by being touched within
the solution, either with a common iron wire or by any other
metal which chemically acts upon the copper salt, at the very
moment of contact a film of copper makes its appearance on
the platina. Now if, according to the views of Volta, electri-
city be excited by the mere contact of different metals, in the
case in question a current should be produced, and in con-
sequence of such a current chemical decomposition should
take place, that is to say, copper should be eliminated at the
platina. But from such not being the case, it follows that
there is no current, consequently no electricity, produced by
the contact of iron and platina. By having recourse to the
galvanometer, the absence of a current under the circumstances
mentioned is placed bej^ond doubt. If the inactive iron wire
is connected with one end of the wire of the galvanometer, the
platina wire with the other one, and if the two free ends of
the iron and platina wires are plunged into a solution of
blue vitriol, not the least deflection of the magnetic needle
takes place; but as soon as the part of the inactive iron wire
immersed in the solution is touched with a metal capa-
ble of causing chemical action, the needle becomes agitated,
and at the same time a deposition of copper takes place on
both wires. From this fact it appears that the oxidation of
iron has no sooner been occasioned than two effects of a
current are produced ; chemical decomposition of an electro-
lyte, and affection of the needle. Now as previously to oxida-
tion no such effects are obtained, we are fully entitled to draw
the inference, that the phaenomenon of oxidation bears to

* See Mr. Faraday*s conclusive proof, also drawn from the relation of
iron ami platina, Lend, and Edinb. Phil. Mag., July 1836, p. 60.— Edit.

2 N 2

276 Mr. H. M. Noad on the peculiar

that of a current the relation of cause to effect, or, generally
speaking, that voltaic electricity is due to chemical action and
by no means to contact.

I am quite confident that inactive iron can be used in a
great number of cases for obtaining results similar to that just
spoken of, and that the peculiar state of this metal offers to
philosophers in many other respects a most valuable means
for making electro-chemical researches.

Bale, October 1836.

L V. On the peculiar Voltaic Condition of Iron,
By H. M. Noad, Esq,

To the Editors of the Philosophical Magazine and Journal,

Gentlemen,
nPHE singular phaenomena presented by iron when put
-■■ under certain circumstances into nitric acid, which have
been so well described in your Magazine by Professor
Schoenbein, and for which Dr. Faraday has, with his usual
ability, offered an explanation, had such an interest with me
that I was induced to repeat all the experiments which have
been described in your Journal ; and in the course of these 1
was led to make other observations, which if you think worth
while I shall feel obliged by having inserted in your next
publication. When a wire that was made inactive by platina
was dipped into a vessel of nitric acid, sp.gr. 1*374, and con-
nected with the galvanometer, and a common iron wire, Jirst
connected with the galvanometer, and then dipped into the
acid, no action either electrical or chemical took place ; but if
it was put into the acid first there was always strong action,
and the needle was deflected in the same manner as if the se-
cond wire was zinc and the first platina ; action was then ge-
nerally communicated for a moment to the first wire, and after-
wards both wires were brought to the peculiar state and the
needle was of course quiescent: if now either wire was touched
in the acid with a common iron or copper wire, it was thrown
into action, and the galvanometer was affected, the active wire
playing the part of zinc. If instead of an inactive wire in this
experiment a piece of platina was used, the moment the cir-
cuit was closed and the second wire was in action, bubbles of
gas made their appearance on the platina ; and if a common
iron wire, round which a small piece of platina foil was wrap-
ped, was substituted for the platina wire, these bubbles rose
rapidly from all parts of the foil, but not one appeared on the

Voltaic Condition of Iron, 277

iron ; but when the foil was slipped off from the iron the gas
then rose from the iron and continued to do so, but the metal
was not thrown into action.

When two glasses were filled with acid and connected by
a compound platina and iron wire, the platina or inactive iron
in one glass exerted a protecting influence on the iron in the
other, provided the communication was first made through
the galvanometer : a touch, however, with a common iron wire
threw the metal into action, producing a strong electrical cur-
rent. The same was the case when three or four glasses con-
nected by a compound platina and iron wire were employed.

But the most curious fact that I observed was this: the
nitric acid was diluted with water till it had a sp. gr. of 1'204«.
In this acid iron was not protected by platina even when coiled
thickly round it ; on the contrary, it appeared to me that ox-
idation took place with increased rapidity when the platina
was in connection. Neither was the iron protected when the
connection between the metals was made through the medium
of the galvanometer, provided that the iron was dipped into the
acid^rs^ ; but if the metal was f?^st connected with the galva-
nometer and then put into the acid, no action whatever ensued
in any length of time, even after the platina was removed : but
once touching it with another piece of iron always threw it
into action, it becoming instantly covered with a brown nitrate
of iron ; the wire thus made inactive did not possess the power
of rendering other wire so, but was always thrown itself into
action when common iron wire was substituted for the platina,
whether it was connected with the galvanometer frst or not.
The first wire in this case acted as platina and the second as
zinc with regard to the electrical effect that was for the
moment produced.

When two cups were used in this experiment and the con-
nection between them made by a bent common iron wire the
result was the same, the platina in one cup protecting the iron in
the second. The conditions before mentioned being observed,
if now the inactive wire was made active, electrical action
was produced, the current being conveyed across the connect-
ing wire. Things being in this state, if the connecting wire
was removed electrical action ceased ; and if a fresh wire was
bent, and one endijlrst dipped into the cup containing the ac-
tive wire, and then the other end put into the cup containing
the platina, that end was immediately in the 2^eculiar state.
Now here there was no metallic connection whatever between
this wire and platina, still it was preserved inactive, and there
was also no passage for the electrical current, for the needle
of the galvanometer was quite still ; but when by touching with

278 Mr. Brooke on the Intersection of Crystalline Minei-als,

a copper or iron wire it was made active, then there was pass-
age for the current, and the needle was strongly deflected.
From this it appears that when iron is in the peculiar state it
is incapable of conducting a current of voltaic electricity. I
have one more remark to make, which is, when the iron wire
was inactive it was found impossible to make either end of the
connecting wire so ; and if the platina was removed from its
cup and a common wire put in its place, it always made the
wire in the other cup active.

I forbear to make any observations on the cause of these
remarkable phaenomena, as the matter is already in such able
hands that it would be presumptuous for me to attempt to ofl'er
an opinion ; trusting, however, that what 1 have noticed may
be the means of inciting further researches,

I am, Gentlemen, yours, &c.,

Shawford, near Bath, March 14, 1837- Henry Minch.IN Noad.

LVI. On the Intersection of Crystals belonging to different
Minerals in a regular and constant manner. By H. J.
Brooke, Esq., RR.S., Src,^

ON examining lately some specimens of Chabasie from Ire-
land, I have observed several crystals penetrated by cry-
stals of Gmelinite, with their axes in all instances parallel
to those of the rhomboids of Chabasie, and the planes also
corresponding in position with those of the Chabasie, as shown
in the annexed figure. Sometimes the face of the Chabasie is
covered by a single crystal of Gmelinite, and sometimes it is
studded with many small ones.

The inclination of the plane P of Chabasie on the axis is
38° 34<', and that of plane g of
Gmelinite 50°, whence the incli-
nation ofg on P is 11° 26'. This
position is constant in all the cry-
stals I have seen.

I am not aware of any analo-
gous fact having been before no-
ticed, and on looking over my
own minerals, I observe only
two other instances of the same
kind.

One is the combination of Oligiste iron and Rutile. If
we suppose a summit of a rhomboid of Oligiste iron replaced
by a triangular plane at right angles to the axis, and crystals

• Communicated by the Author.

Mr. J. Taylor on Manganese Ore containing Silver, 279

of Rutile to be imbedded in this plane, they will lie in direc-
tions perpendicular to its three edges and to the axis of the
rhomboid.

The other case is the regular coating of some of the crystals
of felspar from Bavaria with cleavelandite. The coated planes
are the M, z, and /, of Hauy, or the M, Kl, and 2, of Phillips,
and the crystalline striae of cleavelandite lie in lines parallel
to the edge between M and L of Hauy, or M and Kl of
Phillips.

In the first and third of these instances the crystallographic
axes of the combining bodies are parallel. In the second
they are perpendicular to each other, the primary form of
Rutile being a square prism. FT T R

LVII. On Peroxide of Manganese containing Silver, from
Mexico, By John Taylor, Esq., F,R.S,y Treas, GeoL Soc,

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

T AM not aware that any ore of manganese has been noticed
■■- as containing silver, and I shall be glad to know whether
is combination is a new one or not.

Some time since Captain Rule informed me that manganese
had been discovered in the Santa Ynez vein in Real del
Monte, and that it contained silver enough to be profitably
extracted by smelting.

I requested him to send me some specimens, which I have
received ; they are similar in appearance to the common per-
oxide of manganese found in this country.

By an assay made of an average sample by Mr. Percival
Johnson, it was found to contain silver at the rate of 12oz.
16dwts. 16grs. in the ton.

By a more complete analysis of the mineral the same gen-
tleman found its composition to be as follows :

Peroxide of manganese 30*6

Oxide of Iron 12*5

Silica 21-0

Alumina 17*6

Lime 1*2

Water 16*7

Silver and loss *4

100-
Another mineral found in the same vein, which the Mexicans

280 On the Electric Shock and Spark from a permanent Magnet.

call Jabon, is steatite intermixed with black particles. The
steatite contains no silver, but the black matter is rich in man-
ganese and iron, and contains by Mr. Johnson's assay 185
ounces of fine silver in the ton.

The processes of reduction in the large way in Mexico
gave a larger proportion of silver than that indicated by the
samples tried here.

I am. Gentlemen, yours, &c.

Chatham Place, March 18, 1837. John Taylor.

LVIII. On the Electric Spark arid Shock from a permanent
Magnet, By the Rev. Wm. Ritchie, LL.D.^ F.R.S., Pro-
fessor of Natural Philosophy in the Royal Institution and
in University College^ London,^

1 N mechanical science it is well known and universally admit-
-*- ted, that \)[\q, prime mover can never produce a greater power
than that which it possesses; and that action and reaction are
perfectly equal and opposite in their effects ; but these great
principles are too often lost sight of when we enter on the inves-
tigation of the actions of those agents we term imponderable.
In the case of a wire conducting voltaic electricity. Dr. Fara-
day has shown that it communicates by induction a similar
electric state and loses a part of its own power. If measure-
ments could be accurately employed there could be no doubt
that the quantity gained by the one would be exactly equal
to the quantity lost by the other. In the case of a per-
manent magnet, or one of hardened steel, there seems still a
good deal of obscurity in its mode of action, as if its magnetism
arranged by induction were held fast by that property of the
steel called by French writers la force coercitive. That this is
not the case, and that the electricity in a permanent magnet
moves within the limited spaces of the crystalline particles
with great facility, may be shown by many examples. If a
circle or ring be formed of steel, welded at the junction and
rendered very hard, so as to be easily broken with a blow
from a hammer, and if it be magnetized by passing one of the
poles of a magnet, a north pole for example, round it continu-
ally in the same direction as indicated by the arrow, the electri-
city will be arranged in a peculiar manner, constituting mag-
netism ^without development of poles. If a covered wire be rolled
round it, as in the annexed figure, and the ends covered with
the cups of a galvanometer, or so connected that the circuit
may be broken at the moment the magnet is broken across

* Communicated by the Author.

On the Action of Electricity^ in Voltaic Combinations. 28 1

by a blow with a hammer, the neetHe will be deflected, or a
spark will appear at the points of
the wire, or if connected with the
human body a shock will be re-
ceived. It is obvious, therefore,
that the electricity in this circle, at
the moment of fracture, is in rapid
motion towards a perfectly new
state of stable equilibrium. From
this new state then the electricity
may be easily put in motion by an
inducing or reacting cause till it

approach or finally gain the state oi tension which it had be-
fore the ring was broken. Hence from what is called a per-
manent magnet we may obtain as power/ill a shock and as
hi'illiant a spark as from a soft iron electro-magnet. If in the
common magneto-electric machine a continuous wire be coiled
round the ends of the permanent magnet, and a simple flat
lifter, without a coil, be made to revolve opposite the poles, an
exceedingly brilliant spark, and a shock too powerful to be
endured, may be easily produced. If the revolving keeper
have also a coil, by joining the ends to form a continuous coil
with that on the magnet the effect may be much increased.

Instead of the revolving lifter of soft iron, another perma-
nent horseshoe magnet may be employed with equal or per-
haps greater advantage. The result of these arrangements
may form the subject of another short communication.

LIX. On the Development and Action of Electricity in
Voltaic Combinations, By F. W. Muluns, Jli.P., F.S.S.-,
M.B.I., ^c.

irjOES the development of a certain force or power of vol-
-*-^ taic electricit}', whether in the production ol] quantity or
intensity effects, depend upon the employment of '^ual sur-
faces of zinc and copper ? This question has been frequently
answered, by some in the affirmative, by others in the nega-
tive, but the prevailing opinion appears to be in favour of
equal quantities of the two metals ; and in the various forms
of batteries in general use we see such arrangements as give
equal metallic surfaces, or nearly so. It is therefore because
this point is still in dispute that I make my observations pub-

• Communicated by the Author.
Third Series. Vol. 10. No. 61. April 1837. 2 O

282 Mr. Mulliiis on the Development and Action

lie, in the belief that the results of a series of experiments,
conducted with care and frequently repeated, fully justify me
in asserting that every battery in present use, which contains
equal surfaces of zinc and copper, is constructed on a wrong
principle, and that in such batteries an enormous quantity of
zinc is consumed without the slightest advantage. I was first
struck by this fact while experimenting with the Wollaston
battery, for I always remarked that the zinc plates were un-
equally corroded, the action being much greater within an
inch of the lower edge of the plates than higher up. I also
found that after using these plates for some time, when of
course the original extent of surface was much diminished,
the power of the battery was quite as great as at first, as-
suming that the plates were clean and the battery fresh
charged. In consequence of these observations I reduced the
size of the zinc plates to a fourth of what they had previously
been, and could not perceive the least diminution in effect;
so that without any greater action in a given time on that part
of the -zinc which I retained, I was enabled to develop the
same power, thereby avoiding the waste caused by the action
of the solution on the remaining parts of the larger plates.
Having thus satisfied myself that a large quantity of zinc ab-
solutely went for nothing in the common batteries, I entered
upon a new series of experiments on the same subject with
my sustaining battery, which, in consequence of its power
not diminishing, gave me a certainty of still more accurate and
satisfactory results than I could have hoped to obtain from a
battery whose power was unequal. In order that others who
may be prejudiced in favour of equal metallic surfaces may
have an opportunity of convincing themselves of the truth of
what has bei-n stated, I think it may be well to give them an
account of a few of the experiments made with the sustaining
battery, which they may perform without any difficulty.

One of the tests of which I availed myself was the magnetic
voltameter, which, for the measurement of small quantities of
electricity or of that of low tension, is, without doubt, as accu-
rate an instrument as any we know. In these instruments there
is of course this defect, that no two of them will, for the same
quantity or force of electricity, afford the same indication in
degrees, which arises from difference in the size of the needles,
length and number of coils, thickness of the wire, &c. ; but
where the same instrument is applied in the comparison of
different effects, it is, as I before stated, as perfect as any with
which we are acquainted. If then we connect this instru-
ment with one of my small cylinder batteries, the copper in

of Electricity in Voltaic Combinations, 283

which is about five inches high, and is surrounded by a zinc
cylinder one fourth of the surface of the copper*, the needle
will be deflected to an angle of, say 75°: now, if we remove the
first cylinder of zinc and substitute another of twice its surface,
we shall find no increased deflection, and therefore no increase
of quantity. In like manner, if we go on enlarging the zinc
surface until at length it equals that of the copper, the indica-
tion of the needle will still be the same, and this though we
have added a large proportion of the two solutions for the pur-
pose of bringing the entire zinc and copper into contact with the
fluids. So far I agree with Mr. Daniell, who also uses small sur-
faces of zinc ; but in prosecuting this experiment it will appear
that I differ as much from that gentleman's conclusions, if he
says that a thin wire of zinc, or a piece of ^inc reduced to the
smallest proportions, will produce no diminution of power, as
in the former part of the same experiment 1 differed from
Marianini, who asserted that the copper should be at least
eight times the surface of the zinc in order to produce the
maximum effect; for if instead of increasing the zinc surface
we now reduce that which was first used, the needle will then
diminish its angle and go on retrograding in proportion as the
zinc is reduced, thus showing that there is a certain propor-
tion between the zinc and copper surfaces which produces the
greatest power. Again, with an electro-magnet of sufficient
size, the battery described, when in proper order, will lift two
hundred weight; add the larger zincs until you bring the sur-
faces equal ; the lifting power is no greater than at first. Again,
take one of my intensity-sustaining batteries, which consists of
three zinc and three copper cylinders one within the other; apply
this instrument to the magnetic voltameter, which will give an
angle of 86° ; then apply it to Faraday's decomposition volta-
meter, and the quantity of the gases produced will be found
to be exactly the same, whether the small cylinders of zinc be
used or larger ones equal in surface to the copper, and the
needle will indicate no greater deflexion in the one case than
in the other. Fully convinced, therefore, by the results of
these and many other experiments too numerous to detail here,
that zinc plates or cylinders about one fourth of the surface
of the copper, produce fully as great an effect as if the surfaces
were equal, I strongly recommend any student of this branch
of science, if he still has any doubts as to the correctness of my

• It may be well to observe that in charging this battery I use two fluids :
one consisting of 1 part of saturated solution of muriate of ammonia to 4
of water, in contact with the zinc ; the other, a saturated solution of sul-
phate of copper, in contact with the copper; a bladder, or what is better, i£
properly managed, white silk, being interposed between the metals.

2 O 2

284 Mr. Mullins on the Development and Action

results, to experiment for himself before he goes to the addi-
tional expense of large quantities of zinc, and of their necessary
consequences, increased expenditure of muriate of ammonia
and sulphate of copper, or acids, if he prefer using them.
The mode of action of the sulphate of copper in the vohaic
circuit is singular, and appears not to have been noticed by any
of those gentlemen who have hitherto used it. The opinion
seems to be, that in order to keep up the electrical action in
regard to quantity as well as tension, it is necessary that the
solution should be kept in a state of saturation. This is not the
case ; the solution does not require the addition of crystals
until nearly every particle of copper has been precipitated
and the liquid has lost almost all its blue tinge, which fact
clearly shows that the effects do not depend upon the quantity
of copper in solution, but upon a certain quantity precipitated
in a given time, and that so long as that quantity remains to
be precipitated, so long is there no diminution of power. In
my batteries, which I have often in action for two or three
months, 1 never keep the solution in a state of saturation ; and
whenever I find that the precipitation has been nearly com-
pleted, I can draw off the original charge (of the sulphate) and
introduce a fresh supply, without the least interference with the
electric action. In cases where crystals are kept in the solution,
I have strong grounds for thinking that the action of the liquid
on these crystals has a tendency to interfere with the full deve-
lopment of electricity in the solution. It would appear from
this peculiar property, if I may so call it, of the sulphate, as
well as from the results of many experiments which I hope to
detail in a future paper, that a large proportion of the electri-
city which becomes sensible in this case is produced by the re-
turn of the copper to its metallic state, which change obliges
it to disengage a certain proportion of the electricity with
which it was previously combined in its state of a salt ; and
further, that the definite proportions of all elements in their
various combinations depend upon the proportions of the elec-
tric aether with which the material molecules are either accom-
panied or combined ; — that this aether governs the definite pro-
portions of all combinations, no two elements having similar
proportions of electricity combining, and those which have
different proportions uniting; — that as there is but one electric
fluid, if it can be so called, negative electricity is an improper
term, less positive being more appropriate; — that electricity is
capable of expansion and contraction under certain circum-
stances ; — that in all cases where two or more elements are
combined, if the addition of another causes new combinations,
separation of one of the original elements, or any other change,

of Electricity in Voltaic Combinations.

285

the element which has been added is either more or less po-
sitive than either of the original elements, so that, under such
circumstances, the material molecules will be instantly sub-
jected to new attractions, the less positive molecule quitting
that for which its attraction was not so strong, and uniting
with the other for which it has a greater attraction ; — that in
proportion to the comparative specific gravities of gases, li-
quids, and solids, so are the quantities of electricity combined
with them, — that element of the gases having the least specific
gravity being the most positive, and that having the greatest
least so*, and in like manner with liquids and solids; — that
heat is merely a property of electricity, becoming sensible in
chemical decompositions and combinations, by its disengage-
ment in large quantity and the difficulty of restoring the equili-
brium ; and this it is which causes a platina wire to become
red hot when the electric current is sent through a reduced
and different conducting medium. Thus, if we revert to the
action of the battery in the precipitation of the sulphate of
copper, a new attraction being brought into play, more power-
ful than that of the oxide for the acid, that union is dissolved,
and the metallic molecules being brought into a state of aggre-
gation, do not in their new state attract the same proportions
of electricity; the consequence is that a large quantity, like
latent heat in cases of condensation, and, indeed, identical
with it, is disengaged, and goes to supply the loss of electri-
city in the circuit.

I believe light, as well as heat, to be a property of electri-
city, else, how account for its existence in its purest form in
vacuo, where electricity is the only agent? But I shall refer
to these subjects again and at greater length when I have more
leisure than I have at present, merely adding that I do not be-
lieve my views to be irreconcilable with Mossotti's theory, and

* As an example, I give a list of a few of the metals, in which I institute
a comparison between their specific gravities, their atomic numbers, and
their electrical states.

Sp. Gr.

Atom. No.

Pos. Elec.

Potassium .

0-865

40

1

Sodium ...

0-972

24

2

Manganese

6850

28

12

Zinc

6-861

34

13

Iron

7-788

28

15

Nickel

8-279

26

16

Cobalt

8-538

26

17

Copper ...

8-895

64

23

Silver

10-474

100

24

Platinum ...

20-98

96

27

286 Heviews, and Notices respectiftg New Booh,

that I am quite satisfied that though chemical action may be
supposed to develop electricity, still electricity itself is the
prime mover; electrical and material attractions and repul-
sions, when brought into play by certain arrangements of ele-
ments, inducing and creating all chemical phasnomena.
February 7, 1837. F. W. MuLLINS.

LX. Reviews^ and Notices respecting New Books.

The Human Brainy its configuration , structure, development^ and phy--
siology ; illustrated by references to the nervous system in the lower
orders of animals. By Samuel Solly, Lecturer on Anatomy
and Physiology in St. Thomas's Hospital. London, 1836, 12mo.

n|"^HIS work of Mr. Solly professes to treat of the development
-i- and structure of the human brain as illustrated by a reference
to the central portions of the nervous system of the lower animals.
We have perused the work with much attention, and no inconsi-
derable degree of gratification, and are free to confess that the object
proposed has been faithfully accomplished. A systematic work of
this description has been much wanted as a class-book in our medical
schools, where the anatomy of the brain is almost invariably taught
as if the organ consisted of isolated fragments of cerebral matter
having- no communication with each other. Mr. Solly, as a teacher
of anatomy at St. Thomas's Hospital, has of late years been in the
habit of illustrating his lectures on this subject by continually
placing before the student the analogues of many parts of the brain
in other animals, and has thrown an interest into this branch of the
subject, which as treated before was dry and insipid.

The first part of the work treats of the nervous system of the
lower animals, and proceeds to the consideration of that of animals
of a higher grade, having more especially in view the law by which
masses of * neurine,' termed ganglia, are concentrated, in pro-
portion to the higher development of the senses of the animals.
To illustrate this part of his subject, amongst many other interesting
points, the author has adduced the anatomy of the nervous system
of the moth, and has shown the progressive development of the
organism from the larva to the imago, " and the striking increase
in the size, and the greater complexity in the form of the nervous
system, when the animal becomes fitted to receive impressions from
the objects which surround it, which it does through the medium
of especial organs of sense."

Mr. Solly has in the elucidation of this part of his subject bor-
rowed largely from the labours of other naturalists, but his extracts
from the works of others are faithfully acknowledged.

The anatomy of the human brain forms the next division of his
subject, and his method of dissecting the organ accords with that
of Reil and Spurzheim. The anatomy is strict and minute, and
our author has made ns acquainted with some new facts connected
with the intricate structure of this complex organism. His de-
scription of the fornix as the " inferior longitudinal commissure,"
differs in some points from that of other authors, and is illustrated

Zoological Society. 287

by diagrams taken from preparations now extant, and open to the
inspection of any scientific person. Tlie " superior longitudinal
commissure " is also new to us. But the most important addition
to our knowledge resulting from the labours of Mr. Solly consists
in his discovery of some distinct fibres of medullary matter con-
necting the cerebellum with the anterior columns of the medulla
spinalis : this connection is most satisfactorily proved, and the solu-
tion it affords to the understanding of many hitherto anomalous
facts in pathology renders this a point of high interest. An ac-
curate description of the origin of the motor nerves from, and the
termination of the nerves of sensation in, the central organ of the
nervous system next follows ; and here again some new features are
apparent. The last part of the work is dedicated to the physiology
of the brain as elucidated by pathological facts ; but we forbear to
enter upon this subject, as it is one of such immense extent. The
work is illustrated by twelve beautiful engravings, and the whole is
highly creditable to the author. * * *

LXI. Proceedings of Learned Societies,

ZOOLOGICAL SOCIETY.
[Continued from vol. ix. p. 522.]

August 9, A SPECIMEN was exhibited of an Ortyx which

1836. -^ Mr. Gould regarded as hitherto undescribed. At the
request of the Chairman he pointed out the distinguishing peculiari-
ties of this new species, which he named and characterized as Ortyx
ocellatus. This bird differs from Ortyx Montezuma in several parti •
culars, but to that species it is most nearly allied.

Mr. Gould also brought before the notice of the Meeting two new
species of Birds from New South Wales, where they had been col-
lected, and subsequently presented to the Society by Captain Sturt.
They are referrible to the genus Zoster ops of Messrs. Vigors and
Horsfield; a group among the Sylviadce, and of which but two species
were known at the time those gentlemen instituted the genus. Mr.
Gould placed on the table six additional species, a portion of which
was from the Society's collection, and the remainder from his own.
In the course of his remarks, Mr. Gould adverted to the surprising
augmentation of species which has now taken place in nearly every
group in ornithology; and characterized the new species mentioned
above as Zosterops alhogularis, Gould, and Zost. tenuirostris, Gould.
They are the two largest known species of the genus.

Notes by W. C. Williamson, Esq., Curator to the Natural History
Society, Manchester, on the appearance of rare Birds in the vicinity
of Scarborough, were then read, of which the following is an abs-
tract.

*'The prominent position of Scarborough with its projecting
headlands separated by deep bays and its high hills covered with
wood, render the neighbourhood a favourite retreat for various tribes
of birds. Among the spring visitors the Siskin may be enumerated.

288 Zoological Society.

which appears in April, remaining only a few days apparently on its
route to breeding-places farther north. It is never seen at any otiier
period of the year, though considered by authors as a winter visitor.
Several examples of the Hoopoe, and one specimen of the Roller,
have been shot in the neighbourhood. The stomach of the latter
was filled with the elytra and other remains of a species of Curculio.
Of the Water Ouzel or Dipper it is stated that, when flying down a
stream it drops into the water and dives under any rails laid across
from bank to bank, rather than fly over them, rising on the opposite
side and pursuing its course. The nest of this bird is occasionally
seen so placed under a projecting ledge that a fall of water was con-
stantly rolling over it, thus rendering it secure from any attacks :
the birds entering by the sides of the fall.

" The Redwing has been seen as late as May; these birds are re-
markable for a peculiar cry uttered when disturbed and about to take
flight.

" The Hooded Crow has been known to breed near Scarborough
on two or three occasions. In one instance, a female Hooded Crow
was observed to pair with a Carrion Crow on a large tree at Hack-
ness, where they succeeded in rearing their young. The Carrion
Crow was shot by the gamekeeper, but the following year the
Hooded Crow returned with a new mate of the same sable hue as the
former one to her old nest. The carrion and young crows were
again all shot ; the old female by her vigilance escaped all the ef-
forts of the keepers to destroy her, and a third time returned with
& fresh mate ; she was not however again so successful, but was
«hot, and is now preserved in the Scarborough Museum. The young
birds varied, some resembling the Hooded and others the Carrion
Crow in their plumage.

" The Great or Thick-kneed Plovers breed on the fallows, and often,
startle the midnight traveller by their shrill and ominous whistle.
This is supposed to be the note so beautifully alluded to by Sir
Walter Scott iu his poem of The Lady of the Lake,

* And in the Plover's shrilly strain
The signal whistle's heard again.'

for it certainly sounds more like a human note than that of a bird.

** The Rough-legged Buzzard breeds occasionally in a precipitous
dell near Hackness. A marked female returned the following year
with a new mate to her former favourite haunt.

"* Three species of the genus Lestris, the Glaucous Gull, Little
Gull, Great Northern Diver, Little Auk, and Long -tailed Duck are
obtained generally during the prevalenceofstrongnorth-easterly winds.
Temminck's Tringa and the Olivaceous Gallinule have been killed near
Scarborough. The Sanderling visits the shore in May and Septem-
ber. Good sport is sometimes gained at Woodcock-shooting in March,
when from any cause these birds are prevented continuing their
journey northward. In one or two instances a Woodcock has been
seen there as late as June."
August23, 1836. — Thomas Bell, Esq., in the Chair. — Inconsequence

Zoological Society » 289

of the lamented decease of the Secretary, E, T. Bennett, Esq., the
usual routine of scientific business was suspended.

September 13, 1836. — A communication was read from J. B.
Harvey, Esq., of Teignmouth, a Corresponding Member of the So-
ciety, on the occurrence of four specimens of the Velella limbosa of
Lamarck, which were found on the beach at Teignmouth after a
continuation of southerly winds and smooth water.

A specimen was forwarded for the Society, and representations of
it in four different points of view accompanied the communication.

Mr. Vigors called the attention of the meeting to a Bird, present-
ing a singular form among the Tinamous, which he had exhibited at
one of the evening meetings in the year 1832, but which, from ac-
cidental circumstances, had not been characterized in the Proceed-
ings. The birds of this group, which forms an immediate connect-
ing link between the Tinamous and the Bustards, were first observed
by Mr. Pentland on a high elevation in the Anlies, and the specimen
before the meeting was brought by that gentleman to this country
and presented to the Society- Mr. Vigors described in detail the
characters of the genus, to which he assigned the name of Tinamotis,
and also pointed out the specific characters of the bird, to which he
had on a former occasion given the name of Pentlandii, in honour of
the distinguished traveller who first discovered the group.

Tinamotis.

Rostrum forte, subrectum, Otidis rostra persimile ; culmine piano.

AlcB mediocres, rotundatse; remigihus prima et septimafere sequali-
bus, brevissimis, tertia et quarttl longissimis.

Pedes tridactyli ; tarsis sublongis fortibus ; acrotarsiis reticulatis
squamis inferioribus grandibus ; digitis longitudine mediocribus, me-
dio cseteris, quse sunt fer^ aequales, longiore, omnibus membrana
utrinque marginatis ; acropodiis scutellatis, squamis maximis ; un-
guihus grandibus, planis, dispansis.

Cauda brevis, subrotundata.

Tinamotis Pentlandii. Tin. corpore cinereo-hrunneo sordidoque
fulvo fasciato, capite colloque similiter striatis ; crisso femori-
busque rufis ; mento albescente.

Plumulse capitis colli ventrisc^Q magis albido, dorsi caudaque ma-
gis fulvo notatse ; narum notis maculis simulantibus. Longitudo cor-
poris, 15; ala, a carpo ad apicem remigis 3ti3e, 10; rostri adfrontem,
1^, ad rictum, 1| ; tarsi, 2; digitorum, unguibus inclusis, medii, 1^,
extemorum, 1^.

Mr. Vigors took the same opportunity of describing and naming
two Parrots in the Society's Collection, one of which, now alive in
the Menagerie, distinguished by a brilliant purple plumage over the
head, nape, and breast, and which came from South America, he
characterized under the name of Psittacus augustus ; the second, of
which two specimens had been procured from the late Rev. Lans-
down Guilding's collection, received from the Island of St. Vincent,
but the precise locality of which was not known, he described by
the name of Psittacus Guildingii.

Mr. Gould, at the request of the Chairman, exhibited to the
Third Series. Vol. 10. No. 61. April 1837. 2 P

290 Zoological Society.

Meeting two tribes of Birds, viz. the Tamatias, from the warmer
parts of America, and the Coursers, from the arid regions of Africa
and India. Mr. Gould obser\'ed, that of the first group, only five
species appear to have been known to Linnaeus; eleven others had
since been added, making sixteen: the Society's collection contained
thirteen species. Mr. Gould exhibited a series of drawings in illus-
tration of the group, and characterized one new species under the
name of Tamatia bicincta.

Mr. Gould stated in conclusion, that this formerly limited group
now constitutes a considerable family, or subfamily, whose members
appear naturally to form themselves into at least three or four genera :
thus divided, the genus Tamatia, Cuv. {Capita, Vieill.) contains 9
species, that of Lypornix, Wagl., 3 species; thsit of Monasa, Vieill., 3
species ; and that of Chelidoptera, Gould, 1 ; the latter being a generic
title provisionally instituted by Mr. Gould for the Lypornix tenebrosa,
Wagl., a species which differs in many essential characters from all
the other members of the group, possessing as it does a very length-
ened wing, and being in every way adapted for powerful flight. He
observed, that he had consulted with M. Natterer on the propriety
of separating this bird from the other members of the group, in which
opinion that eminent naturalist had coincided, and at the same time
stated, that it usually resorted to the topmost branches of the trees,
whence it sallied forth over the forest in search after its insect food,
while, on the other hand, all the other members of the group kept to
low thickets and the neighbourhood of the ground. In their general
economy they offer a striking resemblance to the Shrikes and Fly-
catchers ; they are, however, more indolent in their disposition, and
sit motionless on a dead branch for hours together, until their atten-
tion is drawn to some passing insect, when they sally forth, capture
it, and return to the same branch, which they are known to frequent
for months together. With the exception of three or four species
all the members of this group are confined to the Brazils.

Mr. Gould exhibited six species of the genus Cursorius, one of
which was described as new by the appellation of Cursorius rufus.

This new species of Cursorius was from the islands of the Indian
Ocean, but from what particular locality Mr. Gould had not been
able to ascertain. It differs from Curs. Asiaticus, by being smaller
in all its proportions, by having the whole of the upper surface of a
rich rufous brown, and by not possessing a white band across the
rump. In its affinities it is closely allied to both Curs. Asiaticus And
Curs. Temminckii.

Mr. Martin placed on the table two examples of the Potto or
Kinkajou from the Society's Museum, and, at the request of the
Chairman, read some notes describing the differences in colour, size,
and comparative measurements of parts in the two specimens, of
which the following is an abstract.

*' The differences which exist in two specimens of the Kinkajou in
the Society's Museum have led me to introduce them to the atten-
tion of the Meeting, as it is not improbable that they may ultimate-
ly prove to be distinct species. The Kinkajou, however, is so rare

Zoological Society, 291

an animal both in the museums and menageries of our country, that
we want the means of ascertaining whether or not, like that allied
animal the Coati, its colour be subject to variations of tint and mark-
ing. But independently of the great difference in colour which
obtains in the two specimens before the meeting, and on which,
taken as a solitary character, we should hesifcite to ground a specific
distinction, at least until we had compared several specimens, it ap-
pears that the ears of the rufous specimen (which was lately pre-
sented by George Vaughan, Esq.) are more elongated than those of
the other, which died in the Society's Menagerie, where it had lived
for many years. It is on this difference, rather than on that of co-
lour, that I have suspected a specific distinction ; though I confess
my suspicions are strengthened by the latter as a concomitant. A
knowledge of the precise localities from which each specimen was
obtained would be of great use, but on this point, unfortunately, I
have not been able to gain any information.

" In distinguishing between the two species oi Kinkajou, I consider
it best to drop entirely the specific title caudivolvulus, (which is ap-
plicable to both, and is descriptive rather of a generic than a speci-
fic character,) the only mode in fact by which to avoid all possibihty
of confusion.

" Our first species will stand as Cercoleptes megalotus. It is di-
stinguished by the form of the ears, which are elongated, narrow,
rounded at the tip, and somewhat flapping ; their length is 1 inch
3 lines, their breadth 7 lines.

'• Internally they are sparely covered with thinly set soft hairs ;
externally they are fully clothed with hairs of a pale yellowish
white.

"The fur is close, short, thick, and rigid; the general colour is
deep reddish yellow, or fulvous, with an obscure band of a darker co-
lour, down the top of the head, the back, and upper surface of the
tail, approaching to chestnut. The sides of the body and the insides
of the limbs are pale fulvous ; the abdomen and throat are nearly as
dark as the back, and a stripe of deep chestnut commences about the
end of the sternum, and is continued to the inguinal region. The
tail is slender, and the hairs of this part are very rigid.

" To our second species we propose to give the name of Cercoleptes
brachyotus.

" llie fur is full, soft, and moderately long; of a universally glossy
yellowish gray clouded with brown, especially over the nose, on the
top of the head, and down the back; and indeed little less so on the
sides of the body and outer surface of the limbs. The abdomen, the
insides of the limbs, and the throat are dusky straw colour. The ears
are broad, short, and rounded ; covered, but somewhat sparingly, on
the outside with fur of the same colour as that of the body : their
length and breadth are equal, namely, 1 inch.

" The tail is moderately thick, being covered with fur of the same
character as that of the body."

Sp. 1. CERCOLEFrEs MEGALOTUS. Ccrcolept. late rufus, strigd
saturatiore, per totam longitudinem capitis, dorsi medii, caudaque
2P2

292 Zoological Society.

suprii excurrente ; laterihus jjallidioribus ; abdomine gvldque rujis,
strigd castaned ahdominali ; auriculis longis, angustis, rotundatis
subpendentibus et extern^ pills pallid^ flavis indutis, cauddgracili ;
vellere denso brevi, at que rigido.

Sp. 2. Cercoleptes brachyotus. Cercol. vellere denso, molli,
et longiusculo, griseo jlavescenti, at brunneo, undato, hoc colore in
capite, summoque dorso, saturatiore : abdomine et guld stramineis
auriculis latis, mediocribus, et erectis, pilis rarioribus fuscis ex-
terne indutis,

September 2 7, 1836. — A communication from Edward Fuller, Esq.,
of Carleton Hall, near Saxmundham, was read, which stated that
his gamekeeper had succeeded last year in rearing two birds from a
barn-door Hen, having a cross from the Pheasant, and a Pheasant
cock ; that the birds partook equally of the two species in their ha-
bits, manners, and appearance ; and concluded by presenting them
to the Society.

The gamekeeper of Edward Fuller, Esq., in a short note which
accompanied the birds, stated that he had bred tiiem, and that they
were three-quarter-bred Pheasants.

The living birds were exhibited at the Meeting, as was also a
living hybrid, between the Pheasant and common Fowl, which was
one of several that had been some years in the Menagerie of the
Society.

Several specimens of hybrids, from the preserved collection in the
Museum of the Society, were placed on the table for exhibition and
comparison. These had been bred between the Pheasant and common
Fowl, the common Pheasant and the silver Pheasant, and the common
Pheasant with the gold Pheasant.

The specimens of the three-quarter-bred Pheasants were consider-
ed interesting, the opinion of the older physiologists having been
that animals bred between parents of two distinct species were un-
productive.

Mr. Yarrell stated, that although generally such an opinion pre-
vailed there were still exceptions. The Proceedings of the Society
for 1831 exhibited one already recorded in Phil. Mag. and Annals,
N.S., vol. xi. p. 138. This communication was received from the
Honourable Twiselton Fiennes, who having succeeded in rearing a
brood between the common Duck and the Pintail, found in the fol-
lowing season these hybrids were productive. Other instances are
also on record which were adverted to. Mr. Yarrell stated, that he
had had opportunities of examining the bodies of hybrids, both of
Gallinaceous Birds and Ducks, and found that the sexual organs of
the males were of large size, those of the females deficient in size,
and not without some appearance of imperfection. The crosses
produced by the breeders of Canaries were mentioned, and the
objects of obtaining them explained. Mr. Yarrell expressed his belief
that the attempt to breed from a hybrid was most likely to be suc-
cessful when a male hybrid was put to a female of a true species.

Mr. Vigors said this was the first instance that had come to his
knowledge of a female hybrid being productive, and he had hitherto

Zoological Society, 293

considered that they were not so : he expressed his desire to see the
female hybrid that had produced the three-quarter Pheasants then
in the room, and hoped that the opportunities whicli tlie Menagerie
of the Society afforded of obtaining additional evidence on this in-
teresting subject would not be lost sight of.

The Chairman (Mr. Owen) stated, that it was the opinion of John
Hunter that hybrids were not productive except in cases where the
generative organs were in a state of perfection, which might be re-
garded as unnatural in hybrids, as in the rare cases recorded of fertile
Mules, between the Horse and Ass. Constant fertility in the hy-
brid j)roved, in the opinion of Hunter, that the parents were varie-
ties of the same species, not distinct species. But the Chairman
stated, that the experiments recorded by Hunter in the ' Animal
CEconomy ' relative to the fecundity of the hybrids from the Dog
and Wolf and Dog and Jackal were incomplete, from the cir-
cumstances of the hybrids having always bred from a perfect
species and not having propagated the intermediate variety inter
se. He trusted that in a short time this test would be applied in
experiments now in progress at the Society's Menagerie, and thus
an additional element be gained towards the solution of this inter-
esting question.

A small collection of Birds from Swan River, presented to the
Society by Lieut. Breton and Capt. Brete, were on the table. Mr.
Gould, at the request of the Chairman, observed upon the collection
generally, and selected two species which he considered as unde-
scribed, a Gallinule and a species of Duck, the latter strictly refer-
rible to the genus Oxyura of L. Bonaparte, Prince of Musignano,
(genus Undina of Gould). Mr. Gould named the Gallinule, Gallinula
ventralis, and the Duck, Oxyura Australis, this being the only in-
stance he had seen of this limited group from Australia. Of this spe-
cies the collection contained both male and female, the latter of
which, in the general distribution of its markings and colouring,
bore so close a reseml)lance to the Hydrohates of Temminck that
the bill alone presented the obvious distinction.

Oct. 11, 1836. —A series of Mammalia selected from the collection
of the Society was exhibited. Mr. Gray made some remarks upon
them illustrative of the value which he conceived was to be placed on
the characters used by M. Cuvier to separate the plantigrade from the
digitigrade Carnivora, and he concluded by stating that be did not re-
gard the nakedness of the sole as a good character to separate the
genera into larger or smaller groups, though from its permanence in
all ages and the state of the species, it furnished excellent characters
to distinguish species, to separate them into sections, and often to
characterize the genera of carnivorous animals ; and in proof of the
latter, he referred to the excellent character which it furnished to
distinguish the species of the genera Herpestes, Mephites, and Lutra.
He further observed, that in many instances the extent of the naked-
ness of the soles appears to depend upon the temperature of the coun-
try that the animal inhabited, and mentioned that several of the
animals living in countries covered with snow, which apply the

294? Zoological Society,

whole of the soles of their feet to the ground, have this part entirely-
covered with hair, as the Wolverine, the Panda, the Seals, and the
Polar Bear ; but that this was not universally the case, for the Ben-
turing, which inhabited the same country as the Panda, has the
soles bald and papillary. He further observed, that the nakedness
of the soles did not appear to be permanent even in the specimens
of the same species in the Squirrel and other Glirine animals ; for
he had observed that the specimens of the grey Squirrels, in the
Northern part of the United States, had this part covered with hair,
whilst those of the Southern parts, had the soles entirely bald ; and
he also observed, that the various species of the Spermophile differed
greatly amongst themselves in the extent of the nakedness of this
part.

Mr. Gray then proceeded to make some remarks on the alteration
in the situation of the teeth, and on the change which takes place
in the form of the carnivorous tooth, in the milk and permanent
teeth of the Carnivora ; and stated, that the milk carnivorous tooth
of the Cat, Dog, Vison, Skunk, Viverra, and indeed of all the genera
which he had been able to examine, had a small central internal
lobe, whilst the same tooth in the permanent set always had a large
anterior lobe; he also stated, that he had observed that the tuber-
cular grinders of the Mustelce often vary considerably in size in the
various specimens of the same species, showing that implicit re-
liance cannot be placed in the size of these teeth as a specific cha-
racter, which several persons have been inclined to do, as it is well
known that the size of such teeth does not depend upon the age of
the animal, as they never alter their size after they are once com-
pletely developed. Mr. Gray then proceeded to point out the cha-
racters by which the new species exhibited were distinguished : two
were said to have formed part of the collection of the late Sir Stam-
ford Raffles, and were therefore supposed to have come from Sumatra;
one of them was a new species of Paradoxurus, called P. leucomy-
stax from its strong white whiskers, and the other Mr. Gray regard-
ed as the tjrpe of a new genus which he called Cynogale, which ap-
peared to be intermediate between Paradoxurus and Ictides, by dif-
fering from both in the length of the face, the compressed form of
the false canines, and the small size and triangular form of the car-
nivorous grinder. Mr. Gray proposed to call it Cynogale Bennettii,
after his late friend, who, he believed, intended to have described
this animal if he had lived. Then followed the description of two
Foxes, (C. Magellanicus and C. griseus), which formed part of the
collection made by Capt. P. P. King, during his survey of the coast
of South America, and a Squirrel (Sciurus Douglasii), and three
Hares, (Lepus longicaudatus, L. Calif ornica, and L. Douglasii), dis-
covered by the late Mr. Douglas in North America. Then the de-
scription of three new species of flying Squirrels from various parts
of continental India, viz. Pteromys Melanotis, P. albiventer, and P.
Leachii; the latter, presented by Mr. Mellishtothe Society, is pecu-
liar for being coloured exactly like the American Sciuroptera, but is
at once distinguished from them by the length and cylindrical form

Zoological Society, 295

of its tail ; and an Herpestes from the Indian Islands, like the black
Herpestes of the Cape, but differing from it in colour and in the
shortness of the tail, therefore called H. brachyurus. Mr. Gray then
proceeded to point out the character, taken from the form of the
soles of the hind feet, by which tlie Skunks could be divided into
three sections or subgenera, and showed the character in the four
species in the collection of the Society, and referred to some other
species belonging to these sections which were in the collection of
the British Museum, where also he stated other specimens of several
of the species, as the Dog, flying Squirrel, and Herpestes, now de-
scribed, were to be found.

Mr. Gould exhibited several specimens and drawings of Birds al-
lied to the well-known Wren of Eifrope ; and, at the request of the
Chairman, proceeded to comment upon, and characterize the unde-
scribed species as Troglodytes Magellanicus, Troglod. leucogastra, and
Thryothorus guttatus, the latter two species froin Mexico.

Mr. Gould also proposed a new genus in the group of Wrens,
under the name of Scytalopus, and which he characterized as fol-
lows :

Genus Scytalopus.

Rostrum capite brevius, compressum, obtusum leviter recurvum.

Nares basales, membrana tectae.

Alec concavse, breves, rotundatae, remige prima abbreviata, tertid,
quarta, quinta et sexta sequalibus.

Cauda brevis, rotundata, (pennis externis brevissimis,) laxd.

Tarsi elongati, atque robusti, antrorsum scutellis tecti ; posterius
fasciis angustis cincti, squamis serpentum abdominalibus, baud dis-
similibus ; halluce elongato et robusto ; ungue elongato ; digitum
anteriorum, medio elongato et gracili.

Hoc genus ad illud in quo Troglodytes verae amplectuntur maxi-
mam affinitatem demonstrat.

Scytalopus fuscus. Scy. corpore totofuliginoso-nigro; capitis plu-
mis nonnunquam argentato-griseis ; rostro nigro ; pedihus hi^nneis.

Long, tot., 2 J unc; rostri, J; alee, IJ; caudce, 1^; tarsi, J.

Hab. in Fretu Magellanico, Chili, &c.

Scytalopus albogularis. Scy. capite cceruleo-nigro ; corpore su-
periore ferrugineo-brunneo, lined transversali nigrd ; caudd paU
tide rufo-brunned ; guld, pectore, abdomineque intermedio albis,
lateribus et crisso pallido ferrugineis lined transversali nigrd ;
mandibuld superiore nigrd brunned ; pedibus brunneis.

Long, tot., 3 J unc; rostri, |; alee, If; cauda, l^; tarsi, J.

Hab. in BrasUid.

Oct. 25, 1836.— Two skulls of the Orang-Utan of Borneo, and a
skin, including the cranium, of an immature Orang-Utan of Sumatra,
were exhibited. Tliey were transmitted to England by Dr. W.
Montgomerie of Singapore, with a statement that the young Su-
matran Orang had died in that gentleman's possession soon after
having acquired additional grinders.

Mr. Owen availed himself of the occasion to make the following
observations on each of the above specimens.

296 Zoological Society.

He stated that the skin of the young Sumatran Orang agreed in
the rufous colour, texture, disposition, and direction of the hair, with
the adult female Sumatran Orang, presented to the Zoological So-
ciety by Sir Stamford Raffles ; like that specimen also, it had no
nail on the hallua: or thumb of the hinder hands *. The posterior
molar es on each side of each jaw correspond to the first permanent
molares of the adult ; the rest of the teeth consisted of the 8 deci-
duous bicuspides, the 4 small deciduous canini, and the 8 decidu-
ous incisores. This state of the dentition was similar to that of the
human child at the 7th year ; but it would be unsafe to infer from
this circumstance that the age of the Orang corresponded : it being
more probable, from the characteristic duration of the immature
state in the human species, that the shedding of the teeth takes
place at a later period than in the Orang.

Of the two crania of the Bornean Orangs, one differed materially
from the other in size and in the development of the cranial ridges.
The larger specimen before the Society, closely resembled the cra-
nium of the Bornean Pongo or adult Orang in the Museum of the
College of Surgeons, and differed, in precisely the same respects as
that specimen, from the cranium of the Pongo (supposed to be Su-
matran) in the possession of Mr. Cross, described and figured in the
1st volume of the Society's Transactions, (p. 380. PI. 53, and noticed
in our report of Mr. Owen's paper, in Lond. and Edinb. Phil. Mag.,
vol. vi. p. 457), which induced Mr. Owen to entertain more strongly
his original suspicion, that that cranium belonged to an Orang
specifically distinct from the great Bornean species (Simia Wurmbii,
Fischer). With respect to the differences alluded to, he stated that
the cranium of the great Bornean Orang was characterized by the
more oblique plane of the orbits, and consequently the straightness
of the contour of the skull between the forehead or glabella and the
incisor teeth ; the external boundaries of the orbit were broad and
had a rough irregular surface, probably in consequence of the deve-
lopment of the callous protuberances which characterize the sides of
the face in the adult males of this species. The symphysis of the
lower jaw was also proportionally deeper than in the (supposed)
Sumatran Pongo. The cranium of that animal in the possession of
Mr. Cross, Mr. Owen regarded as being that of a male individual
from its size and from the development of the cranial ridges.

The sexual peculiarities observable in the cranium of both the
Bornean and Sumatran Pongos are well marked, and are exemplified,
first in a difference of relative size, that of the female being about
^th smaller ; secondly, in a much smaller development of the cranial
ridges ; and thirdly, in the symphysis menti being of less depth, the
cranium of the female approaching in these respects, according to
the usual law of sexual development, towards the characters of the
immature animal. The smaller of the crania of the two Bornean
Orangs, Mr. Owen regarded as indicative of a species of Simia, Erxl.,

[• See Mr. Brayley's notes on this deficiency in the Orangs, Lond. and
Ediub. Phil. Mag., vol. vii. p. 72.]

Mr. Owen on the specific distinctions of the Orangs, 297

equally distinct from the great Pongo of Borneo (Simla Wurmhii,
Fischer, Synopsis Mammalium, p. 32, No. 43), and from the Orang
of Sumatra {Simla Abelii, Fischer, Ibid. p. 10, No. 2*); and whilst
regretting that his conclusion as to the specific distinction of the
smaller Orang, (which, ceteris paribus , must be at least one third less
than either of the two preceding Orangs) necessarily reposed on a
comparison of the cranium alone, he at the same time observed that,
as the cranium in question was in every respect entire, and with
the series of teeth complete, it served to establish that deduction on
the sound basis of dental and osteological characters.

Mr. Owen therefore proposed to designate the lesser Orang of
Borneo, Simla Morlo, and proceeded to describe the cranium as fol-
lows :

" The size and form of the cranium of the Simla Morlo at first
suggests the idea of its being an intermediate stage of growth be-
tween the young and adult Slmia Satyrus, or Pbngo; but this is dis-
proved by comparison of the teeth of S. Morlo, with the permanent
teeth in the adult Pongo, and with the deciduous ones in the
young Simla Satyrus, as well as with the germs of the permanent
teeth concealed in the jaws of the latter. For while the teeth of
S. Morlo are much larger than the deciduous teeth of the young
S. Satyrus, they have different relative sizes one to another from those
w'hich are observed in the permanent teeth of the full-grown: the
molar es and blcuspldes of the S. Morlo being smaller, the canlnl much
smaller, while the upper Inclsores have nearly, and the lower in-
cisores fully, the same dimensions as those of the great Pongo.

" The teeth in the jaws of a quadrumanous cranium may be known
to belong to the permanent series, by the absence oit\\Q foramina,
which, in an immature cranium, are situated behind the deciduous
teeth, and which lead to the cavities containing the crowns of the
permanent teeth, lliis character is very conspicuous on comparing
the cranium of Simla Morlo with that of a young Simla Satyrus, in
which the deciduous series are present, together with the first per-
manent molares. The deciduous teeth in the young Orang, besides
their smaller size, are more or less protruded from their sockets, and
thrust apart from one another by the vis a tergo of their huge suc-
cessors, while the teeth of <S. Morlo are lodged firmly in the jaws ;
and, with the exception of the characteristic inten^al between the
canines and incisors, are compactly arranged in close contiguity with
each other.

" I have re-examined with much interest several crania of imma-
ture Orangs, in order to ascertain if any of these might be the young
of the species in question ; but they have all presented the crowns
of the permanent molares of too large a size, — of a size which shows
that the great Pongo, either of Wurmb or Abel, represents their adult
statef. And these immature crania also indicate the condition to

f The permanent teeth in the Bornean and Sumatran Pongos so closely
correspond in size and shape that I am unable to refer the ci-ania of the
immature Orangs which I have hitherto examined to either species exclu-
sivelv from comparison of the crowns of the concealed permanent teeth ;

Third Series. Vol. 10. No. 61. April 1837. 2 Q

298 Zoological Society.

which they are destined to attain by the size of the orbits, which
exceeds that of the orbits of the S. Morio, the eye having, like the
brain, already in the young Pongos acquired its full size.

*' That the cranium of the Simla Morio here described, belonged
to an adult is proved by the small interval between the temporal
ridges at the crown of the skull, corresponding to the extensive sur-
face of origin of the crotophyte muscles ; and by the obliteration of
the intermaxillary sutures : that it belonged also to an aged indivi-
dual is highly probable from the extent to which the teeth are worn
down, and from the obliteration, notwithstanding the absence of in-
terparietal and lambdoidal crests, of the sagittal and lambdoidal su-
tures.

" The cerebral portion of the skull of Simla Morio equals in size
that of the Pongo, and indicates the possession of a brain at least as
fully developed as in that species, while the maxillary portion is pro-
portionally smaller ; so that, as the cranium rises above the orbits,
and is, like that of the Pongo, more convex on the coronal aspect
than in the Chimpanzee, and wants the prominent supraciliary ridge
which characterizes the African Orang, it presents in the Simla Morio
altogether a more anthropoid character.

" There are, however, the rudiments of the ridges which so re-
markably characterize the cranium of the mature Pongo. Those
which commence at the external angle of the frontal bone pass back-
wards, upwards, and slightly converge, but do not meet ; they gra-
dually diminish in breadth, and, after passing the coronal suture,
subside to the level of the skull ; they are then only traceable by a
rough line, which leading parallel to the sagittal suture, and gra-
dually bending outwards, rises again to be continued into the lam-
bdoidal ridges ; thus circumscribing the origins of the temporal mus-
cles. The lambdoidal and mastoid ridges are broader and more de-
veloped than in the Chimpanzee, but inferior in both respects to
those of the Pongo. The inial region of the occiput is almost
smooth, and is convex, without the mesial ridge, and strong muscu-
lar impressions observable in the Pongo, where a preponderating
weight in front calls for the insertion of powerful muscles behind
to counterbalance it."

The temporal bones join the frontal in Slmia Morio as in the Tro-
glodytes niger; but this structure occasionally is present on one or
both sides of the skull in Simla Satyrns.

The additamentum sutura lambdoidalls is present on both sides

in speaking of the immature specimens of the great Pojigo, I therefore use
the term Simla Satyrus; in comparing the Simla Morio with the adtiU
Pongo, I would be understood as always referring to the Bornean species,
with cheek-callosities, or the Slmia Wurmhil of Fischer. If the specific dif-
ferences of Simla Wurmbii and Simla Ahelii be admitted the term Simla
Satyrus must merj^e into a synonym, as having been applied indiscriminate-
ly to the young of both these large Orangs. In each case, the generic term
Simla is applied in the restricted sense in which it is used by Erxlebeu in
his • Systema Regni Animalis,' 8vo, 1777, and with which the term PithccuSy
substituted by Geoffroy for the genus of Orangs^ is synonymous.

Mr. Owen oti the specific distinctions of the Orangs. 299

in the -S. Morio, and the beginning of the lambdoidal suture may be
faintly traced, but the remainder is obliterated.

Directing our attention to the base of the skull of S. Morio we
observe the occipital /oramew to be less posteriorly situated than in
the Pongo, but more so than in the Chimpanzee. The plane of the
foramen is also less oblique than in the Pongo. ITie occipital condyles
are as far apart anteriorly as in the Chimpanzee. The anterior con-
dyloid ybramiwa are double on each side as in the Pongo-. the carotid
and jugular/oramma open within the same depression; they are rela-
tively further apart in the Chimpanzee : the petrous portion of the
temporal bone, as in the Pongo, is relatively smaller than in the Chim-
panzee, and the articular cavity, or surface for the lower jaw, forms
a larger proportion of the base of the skull.

The other characters of the basis cranii correspond with those
of the Pongo ; and the smaller size of the meatus auditorius externus
is probably associated in both species with a smaller auricle, as com-
pared with the Chimpanzee.

On the bony palate the relative position of the foramen incisivum
corresponds with the development of the incisive teeth, showing the in-
termaxillary bones to be of larger size Tn the S. Morio than in the Chim-
panzee : the situation of the sutures joining these bones to the max-
illaries is indicated by vascular grooves, but otherwise obliterated ;
while in the cranium of a young Pongo of nearly the same size as
that of the Simia Morio, the intermaxillary sutures still remain, cor-
responding to the non- development of the permanent laniaries. It
will be interesting to determine at what period these sutures are ob-
literated in the more anthropoid Simia Morio.

The OS nasi is a single narrow long triangular bone, slightly di-
lated at its upper end or apex, with the basal margin entire, pre-
senting no indications of original separation into two parts, as has
been observ^ed in skulls of the Chimpanzee.

In the contraction of the interorbital space, and the general
form of the orbit and its boundaries, the Simia Morio resembles the
Simia Satyrus, but the orbital cavity, as before observed, is smaller.
In the plane of the orbit and straight contour of the upper jaw, the
Simia Morio resembles the Bornean species oi Pongo or Simia Wurmhii,
rather than the Simia Abelii or Sumatran Pongo.

The orbital process of the os malce is perforated in the S. Morio
as in the Pongo, by several large foramina. ITiere is one principal
and two very small infraorbital /orflm2«a on either side ; the upper
maxillary bones are relatively smaller, as compared with the other
bones of the face, and especially the intermaxillaries, than in the Pow^ro;
a structure which coincides with the smaller proportional develop-
ment of the canine teeth. The nasal aperture has the same form as
in the adult Simia Wurmbii, being more elongated than in the imma-
ture Orang.

The main and characteristic diiFerence then between the Simia
Morio and the Pongo, whether of Borneo or Sumatra, obtains in
the size of the laniary or canine teeth, to the smaller development of
which in the S. Morio, almost all the other differences in the cranium

2Q2

300

Zoological Society,

are subordinate or consequent. The laniary teeth, it may be ob-
served, have little relation to the kind of food habitual to the Orangs;
had they been so related they would have been accompanied with a
structure of the glenoid cavity fitting them, as in the true Carnivora, to
retain a living prey in their gripe, till its life was exthiguished or resist-
ance effectually quelled. But the flattened surfaces on which the con-
dyles of the lower jaw rotate are in subserviency to the flattened tu-
berculate molars, showing the mastication of vegetable substances to
be the habitual business of the jaws, and the application of the lani-
aries to be occasional, and probably defensive in most cases. We
perceive the utility of formidable canine teeth to the Orangs, whose
stature makes them conspicuous and of easy detection to a carnivo-
rous enemy; such weapons, in connexion with the general muscular
strength of the Pongos, enable them to ofl*er a successful defence
against the Leopard, and may render them formidable opponents even
to the Tiger; but in the smaller species, which we have been describing,
to which concealment would be easier, the canines are of relatively
smaller size, and those of the lower jaw are so placed as to be worn
down by the lateral incisors of the upper jaw ; they were reduced in
the specimen described, to the level of the other teeth ; and the points
of the upper canines were also much worn. The size, forms, and
proportions of the teeth which relate more immediately to the food
of the Orangs, viz. the molars and incisors, show indisputably that
the Simia Morio derives its sustenance from the same kind of food as
the larger Orangs. The singular thickness or antero-posterior dia-
meter of the incisors, which are worn down to a flattened surface,
like molar teeth, show that they are put to rough work ; and it is
probable that their common use is to tear and scrape away the tough
fibrous outer covering of the cocoa-nut, and, perhaps, to gnaw through
the denser shell.

With respect to minor differences not noticed in the description,
these may be deduced from the subjoined table of comparative ad-
measurements.

Table of Admeasurements.

Length of the skull from the vertex to the base

of the occipital condyle

Length of the skull from the posterior plane of

the occiput to the margin of the incisors ....
Length of the skull from the posterior plane of "1

the occiput to the fronto-nasal suture J

Length of the skull from the fronto-nasal suture 1

to the margin of the incisors /

Greatest lateral diameter of the skull (at the post- 1

auditory ridges) /

Smallest lateral diameter of the skull (behind the 1

orbits) J

Simia
Morio,
adult.

Smia

Wurmbii,

adult

male.

inch. lin.

inch.

Jin.

3 7

4

6

7 10

10

6

4 4

5

3

4 H

5

7

4 8

5

4

2 4

2

9

Zoological Society,

301

Distance between temporal ridges

Diameter of the skull at the zygomata

Length of the zygomatic /o5sa

Diameter of skull taken between the outsides of 1

the orbits J

Interorbital space

Transverse diameter of orbital cavity

Vertical diameter of orbital cavity

Vertical diameter of nasal aperture

Transverse diameter of nasal aperture

Interspace between infraorbital /oramma

Distance between the inferior margin of the nasal"!

bone and the inferior margin of the intermaxil- >

lary bone J

From the anterior margin of the occipital/oramew 1

to the posterior margin of the bony palate. ... J
Length of the bony palate along the mesial suture.
From the anterior margin of the intermaxillary 1

bones to the anterior palatal /oramma J

Breadth of the crown of the first incisor, upper jaw.
Breadth of the crown of the second incisor, upper 1

jaw J

Breadth of the four incisors, in situ, upper jaw . .
Longitudinal extent of grinding surface of the

molares, bicuspides included, of one side, upper

jaw

Length of the enamelled crown of the canine 1

tooth, upper jaw J

Breadth of ditto

Length of the lower jaw from the condyle to the 1

anterior surface of the sockets of the incisors. J

Length of the ramus of the lower jaw

Greatest breadth of ditto

Interspace between the mental /oram/;2a

}

Simia [

Morio

adult.

inch. lin.

0 7

5 1

1 9

3 6

0 4

1 3

1 6

1 1

0 9

1 7

2 5

2 3

3 li

0 10

0 6

0 3|

1 6

2 2

0 H

0 5

5 7

3 4

2 0

1 8

Simia

Wurmbii,

adult

male.

inch. lin.

0 0
6 9
2 6

4 6

3 3

10

0

8

7
4
9

2 5

1 0
0 9

7 4

4 '7J

3 1

2 1

Mr. H. E. Strickland read a list of Birds noticed or obtained by
him in Asia Minor, in the winter of 1835 and spring of 1836.

He stated that the winter of last year was one of unusual severity
in all parts of Europe. At Smyrna, where he resided from Novem-
ber to February, the weather, which had been mild in the early
part of December, underwent a sudden change about Christmas-
day. A north wind and violent storms of snow brought vast flocks
of northern Birds to take shelter in Smyrna Bay. A frost of more
than three weeks followed, a circumstance almost without parallel
at Smyrna, which is situated close to the sea and in the low latitude
of 38|°. This statement will explain the occurrence in the following
list, of many Birds whose usual abode is in high northern latitudes.

302 Zoological Society,

In the month of February he visited Constantinople, and returned
overland to Smyrna, which he reached at the end of April. A great
change had now taken place in the ornithology of that neighbour-
hood. The spring was now at its height, and numerous summer
birds had arrived, of a more exotic race than those which had been
observed during the winter. Mr. Strickland was now, however, com-
pelled to return to Europe ; but the few days which passed before
he left Smyrna, served to give him a taste of the rich ornitholo-
gical harvest which might be reaped by a summer's residence in Asia
Minor.

The list, which appears in No. xlvi. of the Society's Proceedings,
comprehends 129 species, of which specimens of 73 species had been
obtained by Mr. Strickland, and were exhibited, each being distin-
guished by an asterisk in the Catalogue. The following are ex-
tracts ;

*32. Curruca melanocephala, Bechst. This delicate little bird, which
is only found in the most southern parts of Europe, remains through
the winter in the neighbourhood of Smyrna. It is a retired solitary
bird, frequenting sheltered ravines thickly beset with various ever-
green shrubs.

*34. Sylvia hrevirostris, mihi. Also kiUed in November near
Smyrna. This species, which I believe to be new, may be thus cha-
racterized :

Sylvia brevirostris. Sylv. corpore suprcL olivaceo brunneo, sub-
tus albido ; pedibus nigris.

Plumage closely resembling that of S. Trochilus. Above brovni
with a tinge of olive. A pale yellow streak over the eye. Throat and
breast pale fulvous with a slight tinge of yellow ; belly whitish.
Inner wing-coverts of a pale yellow. Remiges: the 4th and 5th long-
est and equal: the 2nd equal to the 8th. Beak dusky; legs black.

Long. tot. poll. 4 J ; rostri, ^; caudcB, 2^; al(E, 2J; tarsi, J.

DiiFers from S. rufa in its greater size, and from S. Trochilus in
the shortness of the beak, and the dark colour of the legs.

Habitat prope Smyrnam. Hyeme occisa.
*56. Emberiza cinerea, mihi. This new species is thus characterized';

Emberiza cinerea. JE?nb. capite viridi-jiavescente ; corpore suprcl
cinerascenti, subtHs albo.

Male. Crown of the head greenish yellow, becoming cinereous at
the nape. Back cinereo-fuscous with an obscure streak of brown in
the middle of each feather. Rump cinereous; tail dark brovm ; the
two lateral pairs of feathers white on the inner webs for near half
their length towards the extremities.

Wings dark brown, the coverts and quills margined with whitish,
the scapulars with fulvous. Chin and throat yellow, becoming green-
ish on the cheeks.

Breast cinereous ; abdomen white, sides cinereous.

Bill dusky; legs flesh-coloured.

Long. tot. poll. 6; rostri, f- ; alee, 3^; caudce, 2|; tarsi, f.

The beak of this species most nearly resembles that oiEmberizaCia.

Habitat in coUibus juxta Smyrnam. Mense Aprili occisa.

68. Corvus Monedula, Linn. Common near Smvma.

Zoological Society, 303

Obs. The common Rook was not noticed, and I do not believe that
it exists in the country.

*70. Garrulus melanocephalus, Bonelli. This bird was first described
by M. Gen^ in the Memoirs of the Academy of Turin, vol. xxxvii.
p. 298, PL I., from specimens in the Turin Museum, received from
Lebanon. It is common in the vicinity of Smyrna, and its note and
habits are identical with those of the European Jay, whose place it
supplies.

79. Phasianus colchicus, Linn. Common near Constantinople on
both sides of the Bosphorus. It has probably migrated thither spon-
taneously from Colchis, its native country,

*86. Columba camhayensis. Lath. This bird inhabits the Turkish
burial-grounds at Smyrna and Constantinople, which are dense forests
of cypress trees. It is strictly protected by the Turks, and it was
with some difficulty that I obtained a specimen. It was, perhaps,
originally introduced by man, but now se^ms completely natu-
ralized.

87. Otis tarda, Linn. Frequents the plains south of Smyrna. It
is called wild Turkey by the European residents.

*88. Otis tetrax, Linn. Abundant during the winter in the poultry
shops at Smyrna.

*94. Ciconia alba,'Belloii. Very abundant in Turkey during sum-
mer. It swarms in every village, and is protected with the same
strictness by the Turks as by the Dutch. It is said to have quite
deserted Greece, since the expulsion of its Mahometan protectors.

* 1 1 1 . Podicepsc ristatus. Lath. The young of this bird isa bundant
in the harbour at Constantinople, where, in common with all other
waterfowl, it is strictly protected.

*\V2. Puffinus Anglorum,'R.diy. Flocks of this bird are constantly
seen flying up and down the Bosphorus. They are rarely seen to
alight, and from their unceasing restlessness, the Franks of Pera
have given them the name of dmes damn^es. I am not aware that
this bird has before been noticed in the southern parts of Europe.

Of Vultur, Illig.,and JyM^7a, Briss.,two or three species frequent
the neighbourhood of Smyrna, but all Mr. Strickland's endeavours to
procure specimens of these wary birds were unavailing.

Mr. Strickland also exhibited the skin of a variety of the common
Fox, Canis Vulpes, Linn., which occurs near Smyrna: together with
a specimen of the Lepus hyhridus. Pall., from the South of Russia
purchased of a furrier at Rome.

Also a specimen of an Argonauta, Linn., which was brought to him
in Cephalonia with the animal alive in it. Mr. Strickland stated
that he kept it for some hours alive, and when dead it fell out of
the shell with its own weight ; proving that there is no muscular
connexion between the animal and the shell. In this instance the
shell did not contain any ova.

Mr. Ogilby called the attention of the Society to two Antelopes
at present living in the Gardens, which he regarded as the Koba and
Kob of BufFon. He expressed his pleasure at having it in liis power
to identify two animals originally described imperfectly, and of which
the zoological characters have been hitherto almost unknown ; ob-

S04 Zoological Society,

serving that the re-discovery of an old species was at all times more
gratifying to him, and, he considered, more beneficial to the science
of zoology, than the original description of twenty that were new ;
because, whilst it equally added an authentic species to the substan-
tive amount of our knowledge, it had the further merit of dispelling
the many doubts and surmises which unavoidably obscured the sub-
ject. Mr. Ogilby entered at some length into the identification of
these two interesting species, referring to the scanty materials afforded
by the original descriptions of Buflfon and Daubenton, and pointing
out the various other Ruminants with which subsequent naturalists
had confounded them ; at the same time reserving his more detailed
demonstration of this subject, and his descriptions of the animals
themselves, for the monograph which he has been long preparing for
the Transactions of the Society. Among other errors, he pointed
out that the Koba of Pennant {A . Senegalensis) was the Caama ;
and that the Korrigum of Denham and Clapperton's Travels, identi-
fied with A. Senegalensis by Mr. Children and Colonel Smith, was a
very distinct animal from the Koha, and even belonged to a different
natural genus. It has horns in the female sex and lachrymal si-
nuses, both of which characters are absent in the Koba : he there-
fore proposed to distinguish the Bornou animal by the specific name
oi A. Korrigum. The same observation applies to the two species
which Colonel H. Smith has described under the names of A. Ade-
nota and A. Forfex, and which he identified with the Kob and Gam-
bian Antelope respectively; both these animals had lachrymal sinuses,
w^hereas, both BufFon and the more accurate Daubenton, expressly
declare that the Kob is without this character. The animals in the
Gardens, however, corresponded in all respects with the original de-
scriptions; their comparative size, their colour, their habitat, their
zoological characters, as far as they were reported, and, in the case
of the Koba, even the name, were identical ; and it therefore gave
him peculiar satisfaction to be able to congratulate the Society on
the possession of two of the rarest and most interesting Antelopes
ever brought together. He observed, in conclusion, that the female
of the Kob had been observed by him six or eight months ago in
the Surrey Zoological Gardens, but that he had only recognised its
identity with Buflfon's animal on the arrival of the fine male speci-
men at present belonging to the Society.

Mr. Ogilby afterwards exhibited the skin of a Fox from the Hima-
layan mountains, which he has described in the Zoological Part of
Mr, Royle's "Flora Himalaica," under the name of Canis Himalaicus .
This animal, of which Mr. Ogilby stated that he had examined three
skins, two belonging to the Zoological Society, and one procured by
Mr. Royle at Mussooree, (the two former in their summer, the latter
in its winter dress,) appears to be rare in Nepaul, since Mr. Hodg-
son has never been able to procure a specimen, but contents himself
with indicating its existence (see Catalogue of Mammalia of Nepaul) ;
it is not uncommon, however, in the Doon, in Kumaon, and the more
western and elevated parts of the Mountains, w^here it is called the
hill Fox by the Europeans, and greatly admired for the beauty of its
form, and the brilliancy and variety of its colours. The w hole length

Zodogical Sodeiij/, 305

to the origin of the tail is 2 feet C inches ; th-at of the tail, 1 foot 6
inches; that of tire ears, 4 inches; and the height may be about 1 foot
4 or 5 inches. The animal agrees with the common European and
American Foa^es, (C Vulpes and C.fulvus,) in the black marks on
the backs of the ears, and in front of the hind and fore legs. The
ooat consists of long close rich fur, as line as that of any of the Ame-
rican varieties, and of infinitely more brilliant and varied colours. It
consists of two sorts of hair, an interior of a very fine cottony tex-
tare, and a,n external of a long«ilky nature, but perfectly pliant, and,
like the fur of the Sable, lying almost equally smooth in any direc-
tion. The inner fur is of a smoky blue or brown colour along the
back, as is likewise the basal half of the outer silky hair, which, up to
t^is point, is of the same soft cottony texture as th-e interior fur; it
then assumes its harsher silky character, is marked with a broad
whitish yellow ring, and terminated by a lonff point of a deep bay
colour. Hence, along the whole upper surface of the head, neck,
and back, the uniform colour is unmixed deep and brilliant red. On
the sides of the neck, on the throat, ribs and flanks, is pure white,
changing to light smoky blue on the last-named parts. The outer
hair of the hips and thighs is tipt with grey instead of red, which
gives these parts a hoary appearance, and this colour predominates
on all the ujjper parts of the Society's two specimens, in which the
fur is moreover much shorter and coarser, and the colours less bril-
liant and varied than in Mr. Royle's. The wdiok under surface of
the body is of a smoky brown colour, without any intermixture of
long silky hairs. The external colours of the body arc, therefore,
bright bay on the back, yellowish red on the sides of the body,
white on the sides of the neck, hoary grey on the hips, and smoky
brown on the throat, breast, and belly. The ears are pretty large
and elliptical, their outer surface black; a stripe of the same colour
runs down the front of the legs, both fore and hind ; the soles of the
feet are thickly covered with hair of a yellowish brown colour, ex-
cept the balls of the toes, which are naked. The brush i« large and
well finished, of the same colour as the body throughout the greater
part of its length, and terminated by a large white point.

Mr. Gray related a series of facts in reference to the habits of a
Cuckoo, which appeared to prove that the female, though she leaves
the eggs to be hatched by another bird, sometimes at least takes
care of the young bird and feeds it after it leaves its nest, and teaches
it to fly. They may exphun how they are taught to migrate.

He also expressed same doubt respecting the eggs of Ciickcos be-
ing laid in the nest of Granivorous birds, and stated an instance
where a chicken had been hatched under a Pigeon, that the Pigeon
neglected it when it found that it would not eat the soaked peas, and
eventually ejected it from its nest.

Mr. Gray then exhibited and explained a peculiarity in the struc-
ture of the ligaments of bivalve shells, and pointed out the pecu-
liarity of some mactraceous shells which had this part, contrary to
the general structures, inclosed in the cartilage pit, observing that
this structure was found in his genus Gnathodon, and in a new genus.

Third Series. Vol. 10- No. 61. April 1837. 2 11

306 Geological Society.

which Mr. Gray had called at the British Museum Mulinia, of which
he described five species ; and he also stated the necessity for forming
a new genus, of which Mactra Sprengleri may be regarded as the type.

Mr. Harvey, of Teignmouth, exhibited various fossils from Devon-
shire. Of these, sections in different directions had been made, and
the surfaces highly polished. The structure was thus rendered
beautifully apparent.

Mr. Harvey also exhibited various specimens oiAsteriassind Ophiura
from the Devonshire coast, and explained the mode by which they
had been prepared.

Mr. Gould brought under the notice of the Meeting several spe-
cies of Birds from New South Wales, which he considered to be
new to science, as they are not contained in the collection of the
Linnean Society; nor, as far as he is aware, described in any publica-
tion. Mr. Gould embraced this opportunity to characterize and
name ten species, and stated that at subsequent meetings of the So-
ciety he would bring forward the remainder of his collection.

Mr. Gould more particularly pointed out a species of Petroica ; a
new and interesting species of Ptilonorhynchus , allied to Ptil. nu-
chalis, and which he proposed to make the type of a new genus ; a
new species (belonging to the Society) of the genus Calyptorhynchus,
which he compared with all the other members of the group then on
the table, and described as Calyptorhynchus Naso ; and four new spe-
cies of the genus Amadina, Swains., which he named Amadina cincta,
ruficauda, modesta, and Castanotis. The species are as follows, their
characters, as usual, being given in the " Proceedings " : Petroica
phoenicea ; Amadina Castanotis, modesta, cincta, and ruficauda ; Calo-
dera maculata ; Cracticus hypoleucus and fuliginosus ; and Calyptor-
hynchus Naso.

GEOLOGICAL SOCIETY.

Anniversary Meeting, Feb. nth, 1837. — On'the occasion of pre-
senting the Wollaston Medals, the President, Charles Lyell, jun.,
Esq., F.R.S., addressed the Meeting in the following manner :
Gentlemen,

You have just learnt from the Report of the Council that they have
this year awarded two Wollaston medals; one to Captain Proby
Cautley of the Bengal Artillery, and another to Dr. Hugh Falconer
of the Bengal Medical Service, for their geological researches and
their discoveries in fossil geology in the Sub-Himalayan mountains.
I shall now request one of our Secretaries, Dr. Royle, to take
charge o^ these medals.

The President then addressed Dr. Royle :
Dr. Royle,

It will, I am sure, be most gratifying to you to be intrusted with
the care of these testimonials of our regard for two gentlemen with
whom you are connected by the ties of private friendship. The
Geological Society awards these medals to Capt. Cautley and Dr.
Falconer as an expression of the sympathy which they feel for

Geological Society, S07

those wlio are so zealously labouring in a distant country to pro-
mote a common cause.

In the Address which I am now about to deliver to this Meeting,
I shall have an opportunity of enlarging on the discoveries which
these gentlemen have made in a region previously unexplored, at
the southern base of the Himalaya between the Sutledge and the
Ganges. I shall then speak of their perseverance and industry in
examining the structure of the hills, and in collecting the remains
of extinct quadrupeds and reptiles, and the talent displayed in
their anatomical determination of new species and new types of or-
ganization. I shall now merely request that in forwarding these
medals, the first which the Geological Society has sent to India,
you will express to Capt. Cautley and Dr. Falconer the lively in-
terest which we continue to take in their researches, and our ardent
hopes for their future welfare and success.

Dr. Royle in reply expressed the high satisfaction he felt on
being requested to take charge of the medals, which it would give
him great pleasure to forward immediately to India. When in that
country, he had had personal opportunities of witnessing the zeal
and enthusiasm with which his friends had laboured, and the great
difRculties which they had overcome when far separated from the
scientific world, and without museums, books, or skilful naturalists
to consult.

He was assured that these marks of attention so honourably
conferred by the Geological Society on Capt. Cautley and Dr. Fal-
coner, would not only encourage and stimulate them to fresh exer-
tions, but inspire others among our countrymen in India with a
desire to cultivate Geology and its kindred sciences.

It was afterwards resolved : —

1. That the thanks of this Society be given to Sir Philip deMalpas
Grey Egerton, Bart., M.P., retiring from the office of Vice-President.
Mr. Whewell and Mr. Murchison, by whom this motion was proposed
and seconded, felt that they expressed only the sentiment of every
Fellow of the Society, in declaring their deep regret at being pre-
vented from including in the motion the name of Dr. Turner, who
had been one of the Vice-Presidents, but whose loss the Society had
then to deplore.

2. That the thanks of this Society be given to Sir Alexander
Crichton, M.D.,William John Hamilton, Esq., Viscount Oxmantown,
nnd Lieut.-Col. W. H. Sykes, retiring from the Council.

On the close of the ballot the scrutineers reported that the follow-
ing gentlemen had been duly elected the Officers and Council for the
ensuing year: —

Officers. — President^ Rev. William Whewell, M.A. F.R.S. :
Vice-Presidents, Rev. W. Buckland, D.D. F.R.S. & L.S. Professor of
Geology and Mineralogy in the University of Oxford; William Henry
Fitton, M D. F.R.S. & L.S. ; George Bellas Greenough, Esq. F.R.S.
&L.S. ; Roderick Impey Murchison, Esq. F.R.S. & L.S. : Secretaries^
Robert Huiton, Esq. M.R.LA. j John Forbes Royle, M.D. F.L.S.

2 R2

309 Geological Societt/.

Professor of Materia Medica and Therapeutics in King's College,
London : Foreign Secretary, II. T. De la Beche, Esq. F.Il.S. & L.S. ;
Treasurer, John Tayfor, Esq. F.R.S.

Council. — F. Hailv, Esq.Treas. U.S. F.L.S. ; W.J. Broderip, Esq.
F.R.S. L.S.J W. Cllft, Esq. F.R.S.; Viscount Cole, M.P. D.C.L.
F.K.S. ; Charles Darwin, Esq. j Professor Daubeny,M.D. F.R.S. L.S.j
Sir P. Grey Egerton, Bart. M.P. F.R.S. j H. Hallam, Esq. F.R.S. >
Leonard Horner, Esq. F.R.SS.L.&E. ; C.Lyell,jun.Esq. F.R.S.L.S.;
Marquisof Northampton, F.R.S.; SirWoodbine Parish, K.C.H. F.R.S.;
Rev.Prof.Sedgwick,F.R.S.L.S.;HenryWarburton,Esq. M.P. F.R.S.

Address to the Geological Society ^ delivered at the Anniversary^ on
the \7th of February, 1837, by Charles Lyell^ Jun.^ Esq.,
President.

Gentlemen,

You will have learnt from the Treasurer's Report that the finances
of the Society are flourishing, and they would have appeared in a
stilt more prosperous condition, had we not expended above 500^.
within the year on onr Transactio^ns. Part of this sum has already
been repaid by the sale of the volume just published, of which I
may safely say that it yields to no preceding number in the value
of Its contents or the extent and beauty of its illustrations.

The total number of Fellows of the Society, exclusive of Ho-
norary and Foreign Members, at the close of the year 1835, was
<;70 ; at the close of 1836, 709 ; being an actual increase, after de-
ducting 14 for deaths, removals, and resignations, of S9 Fellows*.

We iKive to lament the loss of Dr. Henry, of Manchester, so
highly distinguished as a chemist and philosopher, and who took a
warm interest in the progress of our science. Our list of Foreiga
Members has been diminished by two deaths, those of Professor
Hoffmann of Berlin, and Baron Ferussac of Paris.

Professor Frederick Hoffmann was suddenly cut off in his 39th
year, at the moment when the scientific world were impatiently
expecting his account of the Geology of Sicily. You are probably
best acquainted with him as the author of the great Geological Map
of Western Germany, in which he made known the results of many
years of patient and accurate research. This Map, published in 1829*,
was divided into twenty-four sheets, and was followed in 1830 by an
Atlas containing sections, and a more general map on a smaller scale
of the same country. In the same year the autlior*s Geography and
Geology of North-western Germany appearedf, which may be re-
garded as a commentary on the great map, comprising a descrip-
tion of the p!iysical outline of the country, its mountains, valleys,
plains, and river-courses, and a sketch of a portion of its geo-

• The return of the number of Fellows, and the deaths alluded to in this
Address, refers exclusively to the year 183(3, and not to the period inter-
vening between the last and present Anniversary.

t Orograph, und Oeognost. Vcrhaltnisse voni Nordwcstlichcn Dcutsch-
land, 2 vols. Leipzig, 1830.

Geological Society, -"^r-v ^q^

logical structure, embracing the transition and secondary rocks of
the Hartz, Thuringerwald, and Lower Rhine. In the larger map
all the tertiary and alluvial deposits are represented by one colour,
the author having never entered upon the subdivision and classifi-
cation of these formations. He had studied, however, the newer
secondary formations, which were depicted by several distinct
colours, and their history would have been included in the work
above alluded to, had he not been interrupted by his tour in Italy
and Sicily in 1830.

Among his other writings, I may enumerate an Account of Mag-
deburg, Halberstadt, and the adjoining territory, and various papers
which will be found scattered through the journals of Poggendorff
and Karsten, the Hertha, and other German periodicals. The only
fruits which we as yet possess of the scientific expedition sent by
the Prussian Government under Hoffmann's direction to Italy and
Sicily, are some letters written by him during the journey, and an
excellent Memoir on the Lipari Islands ; and a valuable work by
one of his companions. Dr. Philippi of Berlin, who published in
Latin a detailed account of the recent testacea of Sicily, and the
tertiary fossil shells collected in the course of the expedition*.

From Hoffmann's letters it clearly appears that the novelty of the
volcanic and tertiary phaenomena of Southern Italy and Sicily had
made a deep impression on his mind. He had been astonished, on
recognising the identity of the modern trap rocks of the Val di
Noto with those of ancient date in Germany, and the no less striking
similarity of the Siciliant ertiary limestones, containing recent shells
to many calcareous secondary formations of northern Europe. The
Lipari Islands afforded him a field for the examination of modern
igneous rocks, and the slow effects of volcanic heat in modifying
aqueous deposits. The picture which he has given of the fumeroles
of the western coast of Lipari, the principal island of the group, is
graphic and highly instructive. At St. Calogero numerous fissures
are seen permeated by heated vapours which are charged with sul-
phur, oxide of iron, and other minerals, in a gaseous state. Here
the tufaceous and other rocks are variously discoloured wherever
the steam has penetrated, and are sometimes crossed with ferrugi-
nous red stripes, so as to assume a chequered and brecciated ap-
pearance. In one place a felspathic lava lias been turned by the
vapours into stone as white as chalk marl, in another, a dark clay
has become yellow or snow-white, and these effects are not limited
to a small space, but are seen extending for four miles through ho-
rizontal strata of tuff, which rise occasionally to the height of more
than 200 feet. The greater part however of the alterations are re-
ferred to what are properly called extinct fumeroles, or the action
of volcanic emanations which have now ceased, but which must at
one period have resembled those of St. Calogero. Some of these

♦ Philippi, " Enuincratio Molluscorum Siciliae turn viventium turn in
tellure tertiaria fossilium, quoc in Itinere suo observavit Auctur." 280 pages
4to, and 12 lithographic plates, Berlin, 1836.

SW Geological Society.

have produced veins of fibrous gypsum, calcedony, and opal, mi-
nerals which must have been introduced into the rents in a state of
sublimation.

In some places there are tufaceous marls, regularly alternating in
thin beds, with still thinner and countless layers of granular gypsum,
the whole mass being again run through everywhere by irregular
branching veins of silky fibrous gypsum. These strata, thus inter-
sected, present a perfect counterpart to some of the secondary
gypseous marls, both of the keuper and variegated sandstone for-
mations in Germany*.

When reading the Professor's description of these phsenomena,
we share in the pleasure and surprise which he felt on comparing
strata of high antiquity with others of so recent a date, and which,
moreover, owe a portion of that resemblance to changes now daily
in progress.

The writings of Baron Daudebard de Ferussac were not devoted
principally to Geology, but we are indebted to him for several me-
moirs, and among others for an Essay, published in 1814, on fresh-
water formations, with a catalogue of the species of land and fresh-
water shells which were then known to enter into their composition.
Monsieur de Ferussac contributed largely to the Geological section
of the Bulletin Universel des Sciences Naturelles, a journal, of which
he was the chief editor and original projector. This Bulletin had, for
its object, to give a monthly analysis or brief abstract, usually un-
mixed with criticism, of the contents of all new publications in every
department of science. The work was first carried on for a year on a
smaller plan, and then assumed in 1824 its enlarged and permanent
form, being divided into eight sections, one of which was devoted
to Geology, Palaeontology, and Natural History. A monthly
number appeared regularly, on this and each of the other seven
sections, the whole forming together a large octavo volume. In
the organization and direction of this scheme, the Editor was
indefatigable, and he succeeded in obtaining the co-operation
of a great number of the most able and eminent writers. In an-
nouncing the original aim and scope of the undertaking, he laid
stress on the difficulties under which men of science labour in pro-
curing intelligence of new works, written in a great variety of lan-
guages in difierent parts of the world, and frequently buried in the
voluminous and costly transactions of learned societies. He there-
fore expressed a hope that his Bulletin would serve as " a kind of
telegraph" for the rapid conveyance of the earliest intelligence of
inventions and discoveries, so as to prevent philosophers from wast-
ing their time and money in slowly feeling their way to results al-
ready found out by others, and attaining with great labour the very
points from which they might have started. The Geological sec-
tion of the Bulletin was ably supported by MM. Boue, Brongniart,
and other writers, and survived the other sections for some time,

* Liparischen Insehi, p. 41. Leipzig, 1832.

Geological Society, 311

maintaining itself for seven years, till at length it was given up in
1831 for want of sufficient encouragement.

The works of Baron Ferussac on Natural History, and especially
Conchology, would deserve from me a fuller notice, if they were
not irrelevant to the subject of this address.

HOME GEOLOGY.

I shall now commence my retrospect of the proceedings of the
Society, during the last year, by considering those papers which
have been devoted to the Geology of the British Isles. There is
probably no space on the globe, of equal area, which has been so
accurately surveyed as this kingdom; yet the most experienced
geologists are now exploring several parts of it with the feeling
that they are entering upon terra incognita. Not only do they find
'it necessary to trace out more correctly the limits of formations
previously known, but also to introduce new gtoups of fossiliferous
strata and new divisions, in districts before supposed to have been
well investigated.

The carboniferous deposits which are alike interesting, in a scien-
tific and economical view, have deservedly occupied of late the par-
ticular attention of many able geologists, and we have received com-
munications on the subject from Mr. Murchison, Mr. Prestwich,
Professor Sedgwick, and Mr. Peile. The observations of Mr.
Prestwich relate to the coal-measures of Coalbrook Dale, and the
formations immediately above and below them, together with the
accompanying trap-rocks*.

There is perhaps no coal-field in the whole country of equal size
in which the strata have been so much dislocated and shattered.
Mr. Prestwich gives a detailed description both of the principal
and minor faults, their direction, extent, inclination, breadth, and
fall, and the difference of level produced by them in their opposite
sides, which is sometimes slight, but sometimes amounts to 600 or
700 feet. In some instances the change of level is by steps or
hitches, which, it is truly said, may be owing either to unequal re-
sistance, or to a series of small dislocations. The walls of the
fissures in the disjointed strata are sometimes several yards apart,
the interval being filled with the debris of the strata. In other
places they are in contact. In this last case it is particularly re-
marked that the surface of the ends of the fractured beds of coal
and shale is shining and striated. You are aware that this appear-
ance has usually been attributed, and I believe rightly, to the
rubbing of the walls of the rent one against the other, the lines of
the polished and striated surfaces indicating the direction of the
motion, but I have lately seen it objected to this theory, that the striae
are not always parallel, but often curved and irregular, and that
the earthy contents of veins and faults often present the same glit-
tering and striated faces, or slickensides as they have been called. I

[♦ An abstract of Mr. Prestwich's paper will be found in Lond. and Edinb.
Phil. Mag., vol. ix. p. 382.— Edit.]

312 Geological Society »

am familiar with the fact, and have always inferred that the movements
were irregular and complicated, occasionally changing thfiir direction,
and that even when uniform, they may have acted unequally on mate-
rials varying in hardness and pliability. It is much to be desired that
scientific travellers who visit countries shaken by earthquakes would
observe with minute care all the phenomena attending the Assuring
of rocks and buildings. I have been informed by an eye-witness of
one of the late minor earthquakes in Chili, that the walls of his
house were rent vertically, and made to vibrate for several minutes
during each shock, after which they remained uninjured and without
any opening, although the line of the crack was still visible. On
the floor, at the bottom of each rent, was a small heap of fine
brickdust, evidently produced by trituration. In such instances it
would be desirable to obtain fragments of the rent building, and
to compare them with the walls of natural fissures.

In his examination of the fossils of the coal-measures, Mr. Prest-
wich has shown that beds containing marine remains alternate with
others in which fresh-water shells and land plants occur, appearances
which he attributes to the flowing of a river, subject to occasional
freshes, into the sea, rather than to repeated changes in the relative
level of land and sea.

It is certainly the safer course to incline to this hypothesis when-
ever there are no unequivocal signs, as in the Purbeck strata in
Portland, of land plants having become fossil on the very spots
where they grew. For although there may be many river deltas
like that of the Indus, where the land is subject to be alternately
upheaved above, and then let down below the waters of the sea,
yet such oscillations of level must be considered as exceptions to
the general condition of the earth's surface near the mouths of
rivers at any given period. Even in a case like the delta of the
Indus, both the causes above alluded to may be expected to co-
operate in producing alternate fluviatile and marine strata ; for in
the long intervals between great movements of the land, the river
will annually advance upon the sea with its turbid waters, and then
retreat again as the periodical flood subsides, and the salt waters,
after being driven back for a time, will reoccupy the area from which
they have suffered a temporary expulsion.

In the conclusion of his valuable paper, Mr. Prestwich observes
that the carboniferous strata of Coalbrook Dale must once have
been entirely concealed under a covering of new red sandstone,
and they owe their present exposure partly to those movements
which have shattered and elevated the coal measures, and partly to
extensive denudation. It is natural therefore to inquire how many
other coal-fields may still lie buried beneath the new red sandstone
of the adjoining district.

In relation to this point of great practical importance, Mr. Mur-
chison formerly offered some conjectures, when speaking of the proba-
ble passage of the 10-yard coal of the Dudley field beneath tlie new
red sandstone, which there flanks it on the east and west. Tliat

Geological Society. 313

geologist now informs us that his conjectures have been verified,
and that at Christcliurch, one mile beyond the superficial boundary
of the coal-field, the 10-yard and other seams have been reached by
borings carried down to the depth of nearly 300 yards. Adverting
to this discovery, he directs attention to the possible extension of
other carboniferous tracts beneath the surrounding new red sand-
stone of Shropshire, Worcestershire, Staffordshire, and other cen-
tral counties.

It is clear that these geological considerations must be duly
weighed by those who speculate on the probable future duration of
British coal, according to the actual or any assumed rate of con-
sumption.

Mr. Murchison, in describing the Dudley and Wolverhampton
coal-fields*, informs us that he has not yet found any fossil remains
of decidedly marine origin, like those observed by Mr. Prestwich
in Coalbrook Dale. The shells seem to be all of fresh-water ge-
nera, and the Megalichthys Hibherti, and other fish occurring at
Dudley, of species identical with those of the coal measures of Edin-
burgh, may have inhabited fresh water.

The same author has coloured on an Ordnance Map the super-
ficial area oi the Silurian rocks connected with the coal-fields above
mentioned, and has shown that the Lickey quartz rock between
Bromsgrove and Birmingham, of which the geological position has
remained hitherto uncertain, is in fact nothing more than altered
Caradoc sandstone, a member of the lower Silurian group. The
same appears as a fossiliferous sandstone in one district, while in
another it passes into a pure quartz rock, a modification attributed
to the proximity of underlying trap, for analogous changes have
been seen at neighbouring points where the absolute contact uf the
sandstone with the trap is visible.

We are also indebted to Mr. Murchison for some interesting
remarks on the dislocations of the strata in the neighbourhood of
Dudley, and particularly for a description of some dome-shaped
masses, from the centre of which the beds have a quaquaversal dip.
He speculates on the probable dependence of these phaenomena
upon the protrusion of volcanic matter from below, at points where
it has been unable to find issue. It would, I think, have been more
satisfactory, if, in confirmation of his theory, some natural section of
one of these dome-shaped masses could be pointed out, where not
only a nucleus of trap was apparent, but could be shown to have
taken up its actual position in a soft or fluid state. Even if we
should find in some instances a subjacent central mass of trap, por-
phyry or granite, not sending out veins or altering the strata, the
folding of the beds round such a protuberance might admit of an
explanation like that suggested by Dr. Fitton. He has supposed
a set of yielding horizontal strata to be pressed upon by a sub-

*[ The abstract of Mr. Murchison's memoir on these coal-fields appeared
in Lond. and I'Minb. Phil. Mag., vol. ix. p. 489. — Edit.]

Third SerUs, Vol. 10. No. 6\, April 1837. 2 S

S 1 4 Geological Society,

jacent hill or boss of hard rock, in which case the effect of upward
pressure might resemble that seen, on a small scale, in the paper of
a bound book, where a minute knob in one leaf has imparted its
shnpe to a great number of other leaves without piercing through
them*. Whatever hypothesis we favour, it is essential to observe
that such hills as the Wren's Nest near Dudley, and others of similar
ellipsoidal forms and internal structure, do not correspond to the
type of volcanic hills, such as Etna, Mount Dor, or the Cantal. In
both cases there may be an approach to a cone, and the beds may
dip everywhere outwards from a common centre; but, in the vol-
canic mountain, the beds having an outward dip, thin off as they
appro:ich the base or circumference of the cone, which is not the
case in inclined beds composing the hills alluded to in the neigh-
bourhood of Dudley : nor in the last-mentioned instances do the
lowest or subjacent rocks crop out round the circumference of the
cone, as happens in the instance of the volcanic eminences before
alluded to, where the granite of the country round Mount Dor, the
fresh-water beds and mica schist in the Cantal, the marine deposits
around Mount Etna in Sicily, — each appe^ar at the surface as soon
as we have left the slope of the cone, and advance upon the sur-
rounding low country.

In attempting to explain the principal transverse faults of tlie
Dudley coal-field, Mr.Murchison refers frequently to the theoretical
principles expounded by Mr. Hopkins in his Researches in Piiysical
Geology, a paper printed in the 6th volume of the Transactions of
the Cambridge Philosophical Societyf. Mr. Hopkins has there en-
deavoured to develop, by reasoning founded on mechanical prin-
ciples, and by mathematical methods, the effects of an elevatory
force acting simultaneously at every point, beneath extensive por-
tions of the crust of the earth. He is aware that in nature such a
force must usually act under complicated conditions, so as to pro-
duce irregular phaenomena ; but he observes that in order to have
a clear conception of the manner in which it would operate in pro-
ducing movements and dislocations, it is useful to assume certain
simple conditions to which mathematical investigations may be
applied. When we have deduced in this manner some results free
from all uncertainty, these may serve as standard cases to which the
geologist may refer more complex problems. Thus for example,
a portion of the earth's crust may be assumed to be of indefinite
length, of uniform depth, and bounded laterally by two vertical par-
allel planes, beyond which the disturbing force does not extend.
It is then supposed that a quantity of subterranean vapour or melted
rock, existing at acertain depth, is expanded by heat so as to elevate

• Dr. Fitton, Geol. Trans. 2nd Series, vol. iv. p. 244.

t [Mr. Hopkins's " Abstract of a Memoir on Physical Geology ; with a
further Exposition of certain points connected with the subject," appeared in
Lond. and Edinb. Phil. Mag., vol. viii. p. 227. et seq. A discussion also of
certain parts of the suhject, by Dr. Boase and Mr. Hopkins, will be found
in vol.ix. pp. 4, 14, and 171, et seq. — Edit.]

Geological Society. 315

the superincumbent mass, the resulting fissures in this mass may then
become matters of calculation. According to Mr. Hopkins, recti-
linear lines of dislocation will give rise to a set of longitudinal pa-
rallel fissures, and simultaneously to others precisely at right angles
to them ; whereas in conical elevations, the fissures will diverge
from a centre. If the general axis of elevation be curvilinear, the
longitudinal fissures preserving their parallelism with it will be also
curvilinear, while the transverse fissures being perpendicular to the
former at their points of intersection will no longer be parallel.

To return from this digression, I must now recall your attention
to other papers relating to the carboniferous deposits of England.
The coal-measures of the north-western coast of Cumberland have
been examined by Prof. Sedgwick and Mr. Williamson Peile, who
have described the Whitehaven and other fields in great detail, il-
lustrating their account with a map and sections*. The recorded
observations in numerous sinkings and borings, both in relation to
the succession of the strata and to the complicated faults which in-
tersect them, would have been involved in hopeless confusion, if
they had simply consisted of a statistical collection of facts attested
by miners ; but in this paper, Professor Sedgwick, aided by Mr.
Peile's practical and scientific knowledge, has compared the different
sections and generalized the phaenomena, giving unity and con-
sistency to the whole, throwing the strata into distinct groups, and
referring the several faults to different movements to which succes-
sive periods of time may be assigned.

In connection with these recent contributions to the history of
our carboniferous strata, I am happy to mention the excellent
volume lately published by Professor Phillips, forming the se-
cond part of his Illustrations of the Geology of Yorkshire. It
is almost entirely devoted to a description of the carboniferous
or mountain limestone of Yorkshire and the North of England,
a subject already admirably treated in some papers read before
this Society by Professor Sedgwick, particularly in his account
of the carboniferous chain from Penigent to Kirkby Stephenf.
As these geologists had separately explored the same ground, it
is satisfactory to perceive that the leading divisions which they
have proposed for the classification of the mountain limestone
and associated strata, agree in every essential point. Mr. Phillips
has described the physical geography of the district occupied by
these rocks, their lithological character, stratification, jointed struc-
ture, and the most remarkable faults which affect them, especially
those which have been called the great Penine and Craven faults.
He also treats of the trap dykes which cut through the limestone,
and discusses the probable epochs of the displacement of the strata,
judiciously pointing out the difficulties unavoidably opposed to the

* [Prof. Sedgwick and Mr. W. Peile's paper was noticed in Lond. and
Ediub. Phil. Mag., vol. ix. p. 501.— Edit.]

t Trans. Gool. Soc. 2nd Series, vol. iv. part 1, p. C9. — 1835.

2S2

SIS Cambridge Philosophical Society.

rii^orous determination of tlie date of such dislocations. A large
and very valuable portion of the work is filled with descriptions and
plates of organic remains, especially of the brachiopodous and
cephalopodous molhisca. Most of the species of these classes were
probably inhabitants of the deeper parts of the sea, but there are
fossil shells in the mountain limestone, which the author supposes
to have lived near the shore, and belonging to genera formerly re-
garded as foreign to the carboniferous limestone, such as Isocardia,
Nucula, Pecten, Patella, Turritelia, and Buccinum. Many species
of Zoophytes and Crinoidea are also described and figured in this
excellent monograph.

CAMBRIDGE PHILOSOPHICAL SOCIETY.

Feb. 13. — A meeting of the Cambridge Philosophical Society
was held on Monday evening. Dr. Clark, the president, in the chair.
Read — memoir, &c., by Prof. Rigaud of Oxford, on the proportion
of land and water on the surface of the terraqueous globe -j memoir
by Prof. Challis, on the law of decrease of temperature in ascend-
ing in the atmosphere; memoir by Mr. Kelland, on the transmission
of light through crystallized media.

Feb. 27. — A meeting of this Society was held on Monday eve-
ning, the president, Dr. Clark, being in the chair. A paper by Mr.
Warren, of Jesus College, was read, on the algebraical sign of the
perpendicular, drawn from a given point to a given straight line. —
Mr. C. Darwin exhibited various specimens of rocks, collected by
him in a voyage round the world, made in His Majesty's ship
Beagle, Capt. Fitzroy, and occupying five years. These specimens
were — tubes of fused sand (produced by lightning?) found near
the Rio Plata ; a white calcareous incrustation alternately formed
and removed on the rocks of Ascension Island by a periodical change
in the direction of the swell ; a black incrustation formed by the
spray on the tidal rocks at Ascension ; a white hard calcareous
rock formed rapidly at Ascension ; a recent calcareous formation
indurated by the contact of lava at St. Jago, one of the Cape de
Verde islands. — Afterwards Mr. W. W. Fisher gave an account of a
case of Spina Bifida, accompanied by some physiological and pa-
thological researches on the accumulation of fluid in the ventricles
of the brain. He came, from the facts he brought forward, to the
following conclusions : — That as there exists a correspondence be-
tween the development of the central part of the nervous system
and the organs destined to protect it, (the development of the os-
seous portion being subordinate to that of the nervous, by reason
perhaps of its subsequent formation,) so the organic characters of
the parts contained, and the peculiar construction of the parts con-
taining, require that a reciprocity of adaptation should afterwards
exist between them ; — That the pia mater, except where it is united
with the arachnoid so as to present the generic character of a serous
membrane, possesses a faculty of secreting a fluid, the quantity of
which is limited by the degree of resistance offered by the inclosing
parts, und that it is thereby calculated, by its particular arrange-

Friday Evening Proceedifigs at the Royal Institutioiu 817

ment in the central cavities of the brain and cerebellum, to effect
tiie purposes of temporary or permanent adaptation; — That although
congenital hydrocephalus may, in the first instance, be referred to
certain conditions of the development of the encephalon and its en-
velope, these conditions being associated with, or rather expressive
of, the special or general plastic powers of the economy, yet the in-
ordinate accumulation of fluid in the ventricles of the brain may
alio be partly attributed, at a later period, to the faculty of the pia
mater before specified, or to any obstruction to the flow of venous
blood through the venae Galeni, or the straight sinus; — That the
ventricular fluid does not communicate with the sub-arachnoid ca-
vity of the spine, as described by M. Majendie, and that the infer-
ences which he draws with regard to the movement of the fluid,
from the experiments detailed by him, are fallacious, inasmuch as,
by interfering with the integrity of the organs containing the cen-
tral parts of the nervous system, he thereby removes the most im-
portant condition by which the osseous protection is normally cha-
racterized, and exposes the parts contained to the direct influence
of atmospheric pressure.

March 13. — Dr. F. Thackeray, V.P., in the chair. Read — Sup-
plement to a memoir on the transmission of light in crystallized
media, having reference particularly to the laws of biaxal crystals}
by Mr. Kelland of Queen's College. Memoir on the laws of fluid
motion, by the Rev. S. Earnshaw, of St. John's College. Medical
Statistical Report of Addenbrooke's Hospital for the year 1836.

Mr. Whewell gave an account, illustrated by diagrams, of some
of the recent results of his researches on the tides. It was
stated that the diurnal inequality, or difference of the two tides
on the same day, follows very curious and unexpected laws, which
the author has ascertained by means of a series of calculations,
executed by Mr. Dessiou and Mr. D. Ross of the Admiralty.
This inequality is regulated by the moon's declination, and the ex-
actness with which it conforms to a rule, depending on the declina-
tion, is very remarkable at some places, as Plymouth and Sincapore.
But the declination is followed by the corresponding effect, at inter-
vals of time which are different at different places ; the interval
being, half a day or a day on the coast of the United States j two
days on the coast of Spain and Portugal ; four days at Plymouth ;
five at Liverpool ; and apparently twelve days at Leith. Also the
amount of this inequality is very great in some cases, for instance,
in the Indian Seas. At Sincapore it is so large that one tide is al-
most obliterated ; and at other places, as King George's Town, in
Australia, this obliteration takes place entirely, and there is only
one tide in twenty-four hours at certain periods of the lunation.

FRIDAY EVENING PROCEEDINGS AT THE ROYAL INSTITUTION

January 20, 1837. — Mr. Faraday on Mossotti's reference of electri-
cal attraction, the attraction of aggregation, and the attraction of gra-
vitation to one cause. Signer Mossotti assumes one electric fluid hav-

'318 Intelligence aftd Miscella?ieous Articles*

ing idio-repulsive powers; the particles of matter are also assumed as
mutually repulsive, but matter and electricity are considcrtd as mutually
attractive. All these forces are inversely as the square of the di-
stance, but the second is not quite so strong as the first and third.
These assumptions being made the law of universal gravitation, all
the varieties under which statical electricity presents itself, and the
general condition of aggregation in solids and fluids flow as neces-
sary consequence. For the more complete account we refer to the
original paper by Mossotti in the Third Part of the Scientific Memoirs,
&c. p. ^^S.

Jan. 27. Mr. Brande on f]mbossing. The illustration consisted
chiefly of the embossing of soft materials, as paper, wood, leather, &c,
and was exemplified by the machinery of Mr. De la Rue.

Feb. ?. Dr. Grant on the Development of the Glandular System
in the animal kingdom compared with that in man.

Feb. 10. Dr. Ritchie on the Velocity of Sound, and the discre-
pancy existing between theory and the results of observation.

Feb, 17. Mr. Faraday on Dr. Marshall Hall's Reflex Function of
the Spinal Marrow, and on Mr. Cowper's Parlour Printing Press.

Feb. 24. — Mr. Cowper on type and stereotype founding.

March 3 — Mr. Woodward, A demonstration by the oxy-hydro-
gen blowpipe and lime, and also by models and experiments, of the
general laws and properties of polarized light.

March 10. — Mr. Wilkinson on bronze, and on various combi-
nations of iron and steel to produce the varieties of Damascus.

March 1 7. — Mr. Faraday on Mr. De la Rue's mode of applying
sulphate of copper to the exaltation of the powers of a common
voltaic battery.

LXII. Intelligence and Miscellaneous Articles,

FOSSIL INFUSORIA USED FOR FOOD.

IT appears from a letter addressed to Ehrenberg by Prof. Retzius
of Stockholm, that the mineral substance commonly called Berg-
r^ehl, mountain-meal, described and analysed by Berzelius, and
in which he found silex, animal substance, and crenic acid, is some-
times eaten in Lapland in times of famine, when the Laplanders
mix it with ground corn and bark, to make their bread. It was
used thus in the district of Degerfors in 1833, and is super^iti-
tiously considered as a gift of the great spirit of forests. Retzius
adds that he has discovered in the Bergmehl, nineteen different
forms of Infusoria with siliceous shields, the mineral being wholly
composed of them, and that the analogy which he supposed to exist
between it and the Bergmehl of Franzensbad seems to be well
founded*.

PALEONTOLOGY.

Organic Forms of certain Minerals. — Prof. Ehrenberg lately read
to the Academy of Berlin the following note on the organic forms

• For a description of the Infusoria contained in this deposit, see
M. Ehrenberg's nicinoir on Fossil Infusoria, in Scientific Memoirs, Part III.
p. 400.

Intelligence and Miscellaneous Articles. 3 1 9

which he had observed, with the help of a microscope, in earthy and
soft minerals.

*' An exact microscopical analysis, several times repeated, of up-
wards of a hundred minerals, of different groups, showed me —

" 1. That chalk, both white and coloured, consists of small ellip-
tical bodies, flat and symmetrical, or their fragments, — bodies which
vary in magnitude from -^^ to t^^ lin., and are formed of concen-
tric articulated rings.

** 2. That the Calcaire cotonneux, or Bergmilck, and the Calcaire
iricrustantj or Kalkguhre, consist of small articulated needles, straight
and rigid, often collected together in fascicles, and in which the
articulations or grains (elementary particles, not atoms,) exhibit a
tendency to form a spiral.

**3. That the porcelain earth of the Aue and Calle (true Ka-
olin, in which are likewise found fragments of feldspath,) consists
also of round bodies, larger, to the size of ^V lin*. regular, similar
to those of the chalk, but discoidal or in their fragments.

"4. That the Meerschaum and Bergleder consist of threads or
very finely articulated nets, more or less interlaced or felted
(Jeutres) and flexible, the articulations of which are constantly of a
uniform size.

" 5. That the mixed earths or rocks, as the potters' clay, the
glaises, the pseudo-meerschaum, also exhibit, on microscopical ana-
lysis, very curious facts of the same kind.

*' 6. That even crystallized quartz and mica, as well as some other
minerals, present a granulated appearance of great regularity, either
without their outer surface of fracture undergoing any previous pre-
paration, or after having been warmed or heated to redness.

"7. That by artificial means, such as a red heat, siliceous and
argillaceous substances may be transformed (by the polarization of
the elementary parts, which may be compared to the cellular tissue
of plants,) into a tissue or felt, composed of articulated spiculae.
Nature exhibits this effect in the Meerschaum, and art produces it
in the manufactory of porcelain and the slag of intense furnaces."
—VlnstituU^o. 194.

PYROPHORI OF EASY PREPARATION.
It is well known that when 2^ parts of pure tartaric acid, de-
prived of its water of crystallization, are quickly mixed in a dry
capsule with 8 parts of peroxide of lead, perfectly dry and reduced
to powder, ignition very soon occurs throughout the mass, which is
very vivid and of long duration. This fact, first mentioned by
Walker, would lead to the supposition that other organic substances
would undergo similar reaction with peroxyd of lead ; and this has
been verified by the experiments of M. Bcetliger. On experiment-
ing with the oxalic and citric acids, he found that the action of the
former on the peroxyd of lead was more rapid, and perhaps stronger,
than that of tartaric acid ; while that of citric acid was rather weaker.
Thus, on mixing together 5\ parts of peroxyd of lead, and 1 part of
oxalic acid dried in hot air, or containing 19 per cent, of water.

S20 Intelligence and Miscellaneous Articles.

almost instantaneous ignition of the mass occurs ; but it continues for
a much shorter time than with the tartaric acid, because the oxalic
acid contains less carbon. In order to obtain a pyrophorus with citric
acid, 1 atom of citric acid, previously fused and kept some time in
fusion, then dried and pulverized, must be promptly mixed with
2 atoms of peroxyd of lead at the temperature of 73° Fahr. The
ignition of the whole mass is almost as vivid, and continues for as
long a time as with tartaric acid. Minium, litharge, and carbonate
of lead, mixed with tartaric acid, yield also, according to M. Boetli-
ger, pyrophori, but not so good as those yielded by the pure oxyd. —
V Institute March 1, 1837.

TIVE TO THE LAWS OF MOLECULAR ACTION.

A translation of the memoir by M. Mossotti " On the forces
which regulate the internal constitution of bodies," in which
he has embodied the results on this subject which he has hi-
therto obtained, has already appeared in Part III. of the *' Scien-
tific Memoirs." As, however, the principal result of his labours,
— the mutual identification of the attractive forces of electricity,
aggregation and gravitation, — constitutes one of the most remark-
able discoveries of the present aera in science, we think it desirable
to notice it in the Philosophical Magazine, as a matter of reference.

While reflecting on the Franklinian hypothesis for explaining the
phaenomena of statical electricity, as reduced by iEpinus to the form
of a mathematical theory, and with the addition subsequently made
by Coulomb, proving that electrical attractions and repulsions are
regulated by the law of the inverse ratio of the square of the di-
stance, M. Mossotti conceived the idea, that if the molecules of
matter, surrounded by their atmospheres, attract each other when
at a greater, and repel each other when at a less distance, there
must be between those two distances an intermediate point at
which a molecule would be neither attracted nor repelled, but would
remain in steady equilibrium ; and that it was very possible that this
might be the distance at which it might be placed in the composition
of bodies. Learning subsequently that the attention of geometers
had recently been particularly directed to the molecular forces, as
being those which may lead us more directly to the knowledge of the
intrinsic properties of bodies, he was thus led to recall his ideas on
the subject, and to set about subjecting them to analysis, and he has
submitted to the judgement of philosophers, in the memoir here re-
ferred to, the results of his first investigations. Of the contents of
this memoir the following extracts may be regarded as a summary.

" I have supposed that a number of material molecules are plunged
into a boundless aether, and that these molecules and the atoms of the
aither are subject to the actions of the forces required by the theory
of iEpinus, and then endeavoured to ascertain the conditions of
equilibrium of the aether and the molecules. Considering the aether
as a continuous mass, and the molecules as isolated bodies, I found
that if the latter be spherical, they are surrounded by an atmosphere,
the density of which decreases according to a function of the distance

Intelligence and Miscellaneous Articles, 321

which contains an exponential factor. The differential equation
which determines the density being linear, is satisfied by any sum of
tliese functions answering to any number of molecules. Whence it
follows that their atmospheres may overlay or penetrate each other
without disturbing the equilibrium of the aether. Proceeding in the
next place to the conditions of equilibrium of the molecules, I ob-
served that, for a first approximation (which may be sufficient in al-
most all cases), the reciprocal action of two molecules and of their
surrounding atmospheres is independent of the presence of the others,
and possesses all the characteristics of molecular action. At first it
is repulsive, and contains an exponential factor, which is capable of
making it decrease very rapidly : it vanishes soon after, and at this
distance two molecules will be as much indisposed to approach more
nearly as they would be to recede further from each other; so that
they would remain in a state of steady equilibrium. At a greater
distance the molecules would attract each other, and their attrac-
tion would increase with their distance up to a certain point, at which
it would attain a maximum : beyond this point it would diminish, and
at a sensible distance would decrease directly as the product of their
mass, and inversely as the square of their distance."

" To apply the formulae which we have found, for the purpose of
presenting molecular action, to the phaenomena of the interior con-
stitution of bodies, requires methods of calculation which are not
yet developed, and which must become still more complicated when
the arrangement of the molecules, their form and their density, are
taken into consideration. I have thought it advisable however, in
consideration of the use to which it might be applied by able geome-
ters, not to postpone the publication of this mode of viewing molecu-
lar action. It is a subject which appears to me entitled to the great-
est attention, because the discovery of the laws of molecular action
must lead mathematicians to t^idhW^h molecular mechanism on a single
principle, just as the discovery of the law of universal attraction led
them to erect on a single basis the most splendid monument of hu-
man intellect, the mechanism of the heavens" — Scientific Memoirs^
Part 111. p. 450.

lODAL.

M. Aime has sent to the Academy of Sciences a new compound
which he considers as atialogous to chloral, and which he has named
iodal, because iodine performs the same function in it as chlorine
does in chloral.

This compound was obtained by causing iodine to act upon nitric
alcohol \_alconl nitrique']. By allowing the liquor to remain for
some days it was replaced by a fluid which was of a red colour and
heavier th.m water. The colour was owing to excess of iodine, and
it eventually disappeared spontaneously. In this way the iodal was
obtained nearly pure, except that it retained a little nitric alcohol
and nitrous aether, from which it is easy to free it.

This substance when pure is nearly colourless. It has a sweet
taste ; its odour is somewhat aethereal. When poured on a red-hot

Third Series. Vol. 10. No. 61. ^pril 1837. 2T

322 Intdligence and Miscellaneous Articles,

coal it yielded white fumes, which strongly affected the eyes.
Sulphuric acid decomposes it, and converts it into iodoform. This
process is equally applicable for procuring broraal and chloral, which
may be readily obtained bv heating the solutions — V Institute Feb.
1st, 1837.

ON THE OXIBROMIDES AND SOME OTHER COMPOUNDS OF
TUNGSTEN.

M. Bonnet states that he has obtained two oxibromides of tung-
sten by passing the vapour of bromine over tungstic acid mixed
with charcoal and strongly heated. At a red heat, with a moderate
current of bromine, an oxibromide was obtained, which yielded

Oxygen 603

Bromine 48-00

Tungsten 45-97 100*

The composition of which gives W^ 0% W^ Br'o, which is equiva-
lent to an atom of blue oxide of tungsten and one atom of bromine.
At a higher temperature than in the preceding case, and with the
bromine passing more rapidly, a second oxibromide of tungsten was
procured, which yielded

Oxygen 30

Bromine 60*

Tungsten 37' 100-

The formula of which is W O^ W^ Br'-, which is equivalent to
an atom of tungstic acid with 2 atoms of perbromide of tungsten,
and which ought to be called tungstate of perbromide of tungsten.

Passing chlorine over the same mixture, instead of bromine, an
oxichloride of tungsten was obtained, corresponding to the tungstate
of perbromide of tungsten j this tungstate of perchloride of tung-
sten yielded

Oxygen 4*8

Chlorine 40-0

Tungsten 55-2 100-

This composition corresponds with the formula WO^, W^ Ch'»,
tungstate of perchloride of tungsten.

The tungstates of perbromide and perchloride of tungsten act
upon water as indicated by their composition, but the case is not
the same with the oxibromide W- O', W^ Br'". The analysis of
these compounds was very difficult to perform. — Vlnstitut, Feb. 8,
1837.

ON CHLOROFORM AND CYANOFORM.

M. Bonnet obtained with great facility a large quantity of chloro-
form by heating chloride of lime and acetate of lime in an earthen
retort. It is purified by precipitating the liquor with water, then
distilling the lower stratum of the liquid, which is chloroform, from
chloride of calcium.

Prussian blue or cyanide of mercury was substituted for chloride
of lime, and a liquid was obtained which M. Bonnet supposed to be

Intelligence and Miscellaneous Articles. $2S

cyanoform ; it is purified by distilling it from chloride of calcium ;
by this a colourless soluble liquid is obtained, which does not take
fire by the taper, which has a strong smell of hydrocyanic acid and
tobacco smoke } it is quite neutral, soluble in water, alcohol and
aether ; potash does not readily act upon it. If the operation is well
conducted, that is to say, if the heat be gradually raised, cyanoform
and water only are obtained, without any trace of acetone, acetic
or hydrocyanic acid, for the liquor is not acid, and contains no
acetone, since it is not combustible ; but if a drop of acetone be
added to it, and it be then inflamed, the acetone burns. — Lhistitut,
Feb. J 837.

ANALYSIS OF SILK.

M. Mulder of Rotterdam remarks, that the only analysis of raw
silk which we possess is that by Roard, inserted in the 65th volume
of the Annales de Chimie, which, according to the present state of
science, is incomplete and unsatisfactory.

To analyse silk M. Mulder subjected some yellow raw silk from
Naples, and white raw silk from Amasieh in the Levant, to the suc-
cessive operation of boiling water, absolute alcohol, and acetic acid,
and he examined each of these solutions for the substances which
they might contain.

The cold water dissolved a portion of the colouring matter of
the yellow silk; the solution contained gelatine and albumen, as well
as some cerine ; in the alcohol there were colouring matter, resin,
and a solid fatty matter. The aether dissolved only a certain quantity
of colouring matter and resin which had been partly taken up by
the alcohol. As to the acetic acid, the substance which it dissolved
had all the appearance of albumen. The residue insoluble in this
acid M. Mulder considered as the pure filamentous part of the silk.
The residue obtained by the evaporation of the water, mixed with a
little alcohol, then with aether, gave a little cerine. Both silks when
distilled with dilute sulphuric acid, yielded an acid liquor, to which
the author gave the name of bombic acid, already employed by some
authors.

The quantities of the several substances obtained from each kind
of silk were as under :

Yellow Silk. White Silk.

Filamentous matter 53*37 54*04?

Gelatine 20-66 19-08

Albumen 24-43 25-47

Cerine 1-39 ]-ll

Colouring matter 0*05

Resinous and fatty matter . . 0-10 0*30

100-00 100-00

Journal de Chimie Medicate, Jan. 1837.

FOSSIL MAIZE.

M. Warden announced to the Academy that he had receired
from Philadelphia some specimens of maize which he supposes to

2T2

324 Intelligence and Miscellaneous Articles.

be fossil. This maize is in isolated grains, sometimes agglomerated
but without any apparent order; they were found in the state of
Kentucky, in a district of alluvium , at a depth of five or six feet, in
layers from eight to ten inches thick, and extended from four to five
miles along the Ohio and its tributary the Fish Creek, 25 miles below
"Wheeling. — Journal de Pharmacie, Jan. 1837.

VEGETATION IN A SOLUTION OF ARSENIC.

M. Gilgenkrantz has seen a plant of the genus Leptomitus, or
HygrocrociSi form in a solution of arsenic. This observation, com-
municated by M. Bory St. -Vincent, proves that arsenic, a substance
so very poisonous, and supposed to he destructive to all organized
bodies, is however favourable to the vegetation of some plants.
M. Bory St.- Vincent mentioned on this occasion that M. Dutrochet
had observed about ten years ago the development of a similar plant
in a solution of acetate of lead. — Ibid,

INDIGO.

Sulphindylic acid, — Analogy of alcohol and indigOy considered in
their combination tvith sulphuric acid.
M. Dumas read a paper on indigo. This chemist repeated the
analysis of indigo, and has obtained precisely the same results as
those he arrived at fifteen years back. His analysis gives for the
composition of indigo :

Carbon 7 SO

Hydrogen 4*0

Nitrogen 10'8

Oxygen 12-2 100-0

The author afterwards endeavoured to determine the nature of
the compound which is formed by the action of sulphuric acid upon
indigo. It is known that sulphuric acid has the property of dissolv-
ing indigo, and of receivingablue colour from this solution. M. Ber-
zelius had considered this combination as a kind of emulsion. M.
Dumas, on the contrary, supposes it to be a compound analogous to
sulphovinic acid j he calls it for this reason sulphindylic acid; it
results from a combination of two atoms of sulphuric acid with one
atom of indigo.

This acid forms with potash a salt soluble in water, crystallizing in
fine silky lamellae, of a very deep blue: it produces with baryta a salt
not very soluble in cold water, but more so when heated. The ana-
lysis of these two salts has shown that the formula for indigo is
Q2i H'o AZ'^ 0% and that the sulphindylic acid should be represented
by 2 SO^-f C30 H'o AZ^ O' j adding to this formula one atom of a
base we have that of the sulphindylates.

It is known that by frequently treating indigo with sulphuric acid
a purple matter is formed which is very difficult to isolate from the
blue matter. M. Dumas calls this combination sulphopurpuric acid;
it is represented by two atoms of indigo and two atoms of sulphuric
acid, or of one atom of sulphindylic acid and one atom more of in-
digo : it forms with potash a purple salt, soluble in water.

Intelligence and Miscellaneous Articles, 325

*f3

White Indigo. — M. Dumas analysed the white matter into which
indigo changes when exposed to the action of alkalis and disoxy-
genizing bodies; he found the composition the same as indigo, with
the difference that the white indigo contains nearly two atoms more
hydrogen. This makes it a hydruret of indigo, and not a deoxy-
genized indigo as is generally admitted.

Anilic acid. — This name was given by M. Dumas to an acid for-
merly called indigotic, and obtained by acting on indigo with nitric
acid. This acid has not the same radical as indigo; it is represen-
ted by C2« H« AZ^ 0», and is anhydrous.

Picric acid. — This is the last product of the action of nitric acid
on indigo, generally known by the name of Welter's bitter. It is
composed, according to M. Dumas, of C^^^ H* hZ^ O'i.

M. Dumas thinks that an oxide of azote enters into its composi-
tion.— Journal de Pharmacie, Jan., 1837.

( .

ON SOME OF THE PROPERTIES OF PER-IODIC ACID.

M. Bengiegser obtains this acid by decomposing the periodate of
lead by dilute sulphuric acid and the application of heat, carefully
avoiding any excess of sulphuric acid, as it often, when in excess,
altogether prevents tiie crystallization of the per- iodic acid. When
the decomposition is effected, and as soon as the precipitate is de-
posited, the solution must be poured off, as, by filtration, even at
common temperatures, the acid is apt to be decomposed into iodic
acid J this solution is then to be evaporated at a gentle heat until it
is completely dry and crystallized.

This acid is colourless, and its crystalline form appears to be an
oblique rhombic prism. In its crystallized state, when heated to
266° Fahr., it fuses without decomposing, and by cooling again
crystallizes; at 324?° Fahr. it loses its water of crystallization, and
at about 370° Fahr. it is decomposed into iodic acid, with a rapid
disengagement of oxygen gas. This acid is deliquescent, but may
be kept solid over sulphuric acid. The crystallized acid is soluble
in alcohol and aether, and the solutions diluted seem to suffer no
change by ebullition. An aqueous solution of this acid heated with
phosphorus forms oxide of phosphorus and phosphoric acid. The
crystallized acid, heated with phosphorus, explodes violently, with
the formation of oxide of phosphorus. In both cases the acid is
completely deprived of its oxygen, and its iodine is set free. The
aqueous solution of the acid e.xerts no action upon sulphur, even
when they are boiled together. The action of per-iodic on the tar-
taric, formic, oxalic, and acetic acids is analogous to that exerted by
iodic acid on these bodies, carbonic acid being formed and iodine set
at liberty.

Most of the metals are oxidized by an aqueous solution of per-iodic
acid. At common temperatures it acts on zinc filings, and, when
excess of zinc is employed, the acid is completely reduced, giving
rise to iodine and oxide of zinc. With copper filings it forms iodate
of copper, which is precipitated in white flocks. Iron is converted

326 Intelligence and Miscellaneous Articles,

into deutoxide (oxide ferrosoferrique) and mercury into protoxide^
whilst tin and lead are very slightly acted upon by this acid.

When per-iodic acid is neutralized by carbonate of soda, and pre-
cipitated by neutral nitrate of barytes, the resulting liquid is acid ;
this is also the case with the neutral salts of lead and lime, indi-
cating the precipitation of a subsalt. Per-iodate of lead is white,
but becomes yellow by heat, owing to its losing water. Similar
phaenomena occur with the proto- and bi-salts of mercury, the
former changing from a yellow to a reddish brown, and the latter
from white to yellow, by the application of a gentle heat. Peri-
odate of soda gives a green precipitate with copper salts, which be-
comes more intense by heat, and the proto- and per-salts of iron
form yellow precipitates. All these precipitates readily dissolve in
dilute nitric acid. — Journ. de Pharmacie, Oct., 1836.

ON AN EXPERIMENT IN ELECl^RICITY. BY JAMES WATSON, ESQ.

To the Editors of the Philosophical Magazine and Journal.

Gentlemen,

As the following experiment may easily be made by any person
who has an electrical machine, I think it will be acceptable to many
of your readers.

Take a slip of card about one inch in length and one quarter of
an inch in breadth, and at one end of the card make a slit up the
middle one quarter of an inch long j then bend out the divided
parts in opposite directions, so that the bit of card may be made to
stand upright upon its two short legs. By this means the card may
be so nicely adjusted that a very slight touch will overbalance it,
and cause it to fall. Now take two pieces of stout brass wire, four
inches in length and pointed at each end ; bend the wires at right
angles, in order that each wire may have a short arm or stem, one
inch long. These short arms or stenis are to be inserted a little
way into two holes made to receive them in a flat thick piece of
wood. The two holes must be made at such a distance from each
other that the points ofthetwolong horizontal arms shall be just three-
quarters of an inch apart. Midway between these points place the
bit of card, in an upright position, c

as in the figure, where C repre-^ i - i ^i

sents the edge of the card, having l\ \ \ \ | ^^ \

its two flat sides opposite to the ^\ \^

points of the two wires, A and B. ^ ZZ.^

To insure success in making this delicate experiment, the machine
must be screwed to a very stead?/ table, otherwise the card will be
disturbed by the turning of the cylinder. The best way of making
the discharge is to suspend a small jar from the prime conductor,
and let the jar discharge itself through the electrometer. A chain
must connect the electrometer with the wire A, and another chain
must connect the outer coating of the jar with the wire B.

When the experiment is well performed, I always find that the
card is perforated, and has a bur on each side of it^ but what de-

Intelligence and Miscellaneous Articles, 327

serves particular notice is the very curious fact that the card is not
thrown down.

If two bits of card be placed between the wires, instead of one as
in the last experiment, even then the separate bits of card will con-
tinue to stand, although both will be perforated.

The motion of a single fluid from the positive to the negative
wire, cannot, 1 think, be reconciled with my experiment, which
seems to require two equal repulsive actions.

I am, Gentlemen, your obedient servant,

James Watson.

London, Jan. 31, 1837.

VOLUNTARY SOUNDS OF INSFXTS.

We have received the following communication from a Corre-
spondent relative to Dr. Burmeister's paper " On the Cause of
Sound produced by Insects in Flying," printe^ in the Third! art of
the Scientific Memoirs; in which it is shown not to be caused
by the vibration of the wings, but by peculiar organs placed in the
thorax, a minute account and delineation of which are given.

" I have several times tried the following experiment on the com-
mon large blue fly (Musca vomitoria). While it has been flying about
the room with its usual buzzing noise, I have placed a small piece
of meat on a table, and opened the door of the room. The fly
seems to be soon attracted by the meat, and on approaching and
hovering over it the buzz has appeared to increase in loudness ; but
if, when it has been thus hovering over the table, I have caught at it
with my hand, or attempted to strike it with a handkerchief, it has
immediately flown away, and generally out at the door, without
producing the slightest audible sound, as though it intended to con-
ceal the direction of its flight." X.

[I have often witnessed the silent flight of this insect on being
disturbed or attempted to be caught, exactly as described by our
Correspondent. — E. W, B.j

METEOROLOGICAL OBSERVATIONS FOR FEBRUARY 1837.

Chistvick. — Feb. 1. Foggy: slight frost. 2. Foggy: fine. 3. Hazy.

4. Frosty : fine. 5. Overcast. 6, 7. Sharp frost : very fine. 8. Overcast :
rain. 9. Fine. 10. Fine : rain : stormy at night. 1 1. Boisterous, with
rain : lightning at night. 12. Clear : cloudy and fine : rain. 13. Rain :
fine. 14. Very fine. 15. Foggy. 16, 17. Fine. 18. Slight rain; cloudy :
stormy: about ^ past 10 p.m. a reddish luminous arch was observed, ex-
tending through the zenith, in a direction nearly east and west. 19. Over-
cast: stormy with heavy rain. 20. Very clear: fine. 21. Stormy with
rain : fine. 22. Clear and fine. 23. Stormy with rain. 24. Clear and
cold. 25, 26. Cold and bleak. 27, 28. Overcast.

Boston.— Feb. 1. Foggy. 2. Cloudy. 3, 4. Fine. 5 — 7. Cloudy.
8. Fine. 9. Cloudy. 10. Stormy. 1 1. Rain and stormy : rain early a.m.
12 — 14. Fine. 15. Cloudy. 16, 17. Fine. 18. Cloudy: stormy with rain
P.M. 19. Cloudy : rain p.m. 20. Cloudy. 21. Fine : rain early a.m. :
rain P.M. 22. Cloudy. 23. Rain : stormy night. 24. Stormy. 25. Fine:
snow P.M. 26, Fine. 27. Cloudy. 28. Fine.

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THE

LONDON AND EDINBURGH

PHILOSOPHICAL MAGAZINE

AND

JOURNAL OF SCIENCE.

[THIRD SERIES.]

MAY 1837.

LXIII. Cyanide of Potassium^ an incidental Pi oduct of the
Process for making Cast Iron in Blast Furnaces. By Thomas
Clark, M.D., Professor of Chemistry in Marischal Col"
lege and University, Aberdeen,'*
TOURING the last three years, a salt, which, when melted,
■*-^ is clear and colourless, but which, when solid, is of an
opake white, and generally not cr3'stalline, has been observed
to exude in the liquid state, from cracks, and other accidental
outlets, around the tweers of the hot-blast furnaces for making
cast-iron, in the Clyde iron-works. The salt occurs in greater
quantity at one time than at another ; but I have not yet been
able to ascertain the circumstance in the process upon which
the supply of the salt depends. The workmen say, that it
occurs most after what they call a scour of the furnace, that
is, after, by an excess of the fluxing ingredients of the smelting
process, or an increase of the fuel, the materials acci-
dentally adhering to the inner sides of the furnace have been
dissolved away. The salt in question, however, may exude,
under such circumstances, not because it is produced in greater
quantity, but merely because it then finds a readier outlet at
the tweer, where alone it has hitherto been observed. At
the Clyde iron-works, the salt has occasionally accumulated in
such quantity as to require a wheelbarrow for its removal.
Upon minute inquiry I found that a similar product, although
it had attracted no attention, occurred at other iron-works in
Scotland, wherein, as at the Clyde iron-works, the hot blast and

* Communicated by the Author.

Third Series, Vol. 10. No. 62. May 1837. 2 U

330 Dr. Clarke on Cyanide of Potassium^ as produced

coal for fuel were employed ; but owing to the rare use of coke
in Scotland now, I am, as yet, not aware whether the same
product has been observed where coke is the fuel con-
sumed.

The principal ingredient in the salt thus obtained, is cyanide
of j)otassium. In a quantity that was, about a year ago, sub-
mitted to an examination whereof the sequel will give an
account, the cyanide of potassium made up about 53 parts in
the 100, the rest being carbonate of potash, intermixed with
a small quantity of carbonate of soda; but another quantity
that was examined about a year previously,contained more than
two thirds of cyanide of potassium. One learns, not without
surprise, that so remarkable a product should occur from such
materials, and under such circumstances. That potassium
should be there, from what source as yet I know not, will in-
dicate that the presence of that element, in even unpromising
materials of soils for vegetation, is more general than is usually
suspected. Nor will the iron-master fail, from this intimation,
to warn all under his charge whom it may concern, of the
perilously poisonous character of this product — a warning not
idle, I presume, since on a visit to the Clyde iron-works I
learned that the workmen, having discovered its alkaline pro-
perties, some of their wives, " on household thoughts intent,"
had resolved to make the cyanide of potassium available in their
washing-tubs. The product will, however, better merit the
attention of the pharmacian, as affording a copious and cheap
source whence to obtain cyanide of potassium.

The details of the investigation, having no novelty of me-
thod to boast of, might not be worth giving, were there not
strong reasons for believing that, for want of due precautions,
a similar product has been more than once — in the hands too
of able chemists, mistaken for carbonate of potash. This in-
duces me to give the details,

A portion of the salt, selected as free from insoluble admix-
ture, was dissolved in water, which was done easily, and to the
solution, which was distinctly alkaline, dilute nitric acid was
added, until the solution, being gently heated, became neu-
tral. Effervescence took place. The evolved gases betrayed
the presence of carbonic acid by precipitating lime-water,
and of hydrocyanic acid by the smell of it, which prevailed.
The neutral solution gave no precipitate by nitrate of barytes,
or nitrate of silver, — indicating the absence not only of sul-
phates and chlorides, but that of salts of several other acids
such as these reagents would precipitate. The same solution
was unaffected by sulphuretted hydrogen, by sulphuret of
potassium, by yellow ferro-prussiate of potash, by oxalate

in Hot-blast Furnaces for making Cast-iron, 33 1

of ammonia, or by carbonate of potash — showing the absence
of all metallic bases, except such as are alkaline.

Potassium was proved to be present, and sodium too, by
crystallizing a portion of the same solution, examining the
successive crops of crystals that were formed, and persevering
in the crystallization until there did not remain a drop of the so-
lution. At first the well-known crystals of nitre were obtained.
Towards the end, however, when the solution had become small
enough to be transferred to a watch-glass, little crystals of ni-
trate of soda, in their well-known rhomboidal form, appeared.
This test for the presence of sodium is much more delicate
than might be imagined. But another and a readier test
showed the presence of sodium as decisively. A platinum wire,
scrupulously clean, is, by way of precaution, placed either
before the tip of the inner blue flame of the blowpipe, or so
as to touch the circumference of the blue flame of alcohol. In
either case, the colour of the flame is unaffected by the wire,
if sufficiently clean. Dipped, however, into a strong solution
of any salt containing potassium, and dried above a flame, the
wire will, before the blowpipe, show a violet flame, beyond
the wire, in continuation of the blue one, but short and spread ;
and, in the flame of alcohol, it will tint with a like violet co-
lour all above the wire. But a similar wire, dipped into a
rather strong solution of a salt containing sodium, and treated
in like manner, will give, before the blowpipe, an intense
greenish-yellow light, shaped so as to seem a prolongation of
the blowpipe's blue flame ; and, when placed in the flame of
alcohol, will imbue so much of the flame as is above the wire
with a similar colour. A sodium salt, although intermixed
with one of potassium in a smaller proportion than 1 to 100,
will give, with sufficient distinctness, a like indication of its pre-
sence. Any common gas-light, lowered till it burns blue, will
answer for the detection of sodium in this manner ; but, to ex-
hibit this test on the lecture-table, the flame of alcohol answers
best. By this test, applied in all these modes, the salt exuded
from the blast-furnaces gave distinct indications of the pre-
sence of sodium.

The proportion of nitrate of soda obtained by crystallizing
the mixed nitrates of the two alkalis was manifestly small ; but,
as the two were evidently in a state of mixture — not of com-
bination— it did not seem worth while to ascertain the propor-
tions of each. Nevertheless, I made an approximative expe-
riment, in order to form some idea of the relative proportion
of the intermixed sodium salt. Equal weights of pure chlo-
ride of potassium and of mixed chlorides, formed by treating
the salt under examination bv pure muriatic acid, were se^m-

2 U2

332 Cyanide of Potassium from Hot-blast Furnaces.

rately precipitated by nitrate of silver, the experiment in each
case bein^ conducted in a like manner. The chloride of silver
from the mixed chlorides, was to the chloride of silver from
the chloride of potassium, in the proportion of not more than
1004 to 1000. This corresponds to about 15 of sodium salt
in 1000 of the mixture.

That the salt under examination contained no ferro-prus-
siate of potash, was proved hy first supersaturating a watery so-
lution of it with pure muriatic acid, and then adding a solution
of a protosalt of iron. No blue appeared. That the salt did
contain cyanide of potassium, was proved hy first adding, to
a watery solution of it, a solution of protosulphate of iron,
and then redissolving the precipitate by pure muriatic acid ;
upon which prussian blue appeared.

For want of attending to the order in which these reagents
should be used, an eminent chemist, expressly seeking for the
production of an alkaline cyanide, has merely proved the
absence of a ferro-prussiate, where he conceives he proved
the absence of an alkaline cyanide. — (Ann. de Chim, et de
Phys. tom. lix. pp. 26^', 269.)

To ascertain the proportion of cyanide of potassium, the
method was adopted — which repeated experience has taught
me to regard as the best — of estimating that cyanide from
what peroxide of mercury it can render soluble. All the pre-
caution required is, that the peroxide be pure and in fine
powder. Accordingly, 12 grains of the salt were dissolved in
about 1000 grains of water, and treated with peroxide. Were
those 12 grains entirely cyanide of potassium, they would dis-
solve 20 grains of the peroxide of mercury. In point of fact,
they dissolved, in three experiments, as under:

10*77 grains, corresponding to cyanide of ) _,, g . ,
potassium J

10-77 53-8

10 5 52-5

Cyanide of potassium S^*^ in 100

Having found, by preliminary experiments, that a given
weight of carbonate of potash precipitated from a solution of
chloride of calcium the same weight of carbonate of lime,
whether pure cyanide of [)otassium was added to it or not, I
resolved to estimate the carbonate of potash by that method.
50 grains of the salt gave, of carbonate o^ lime, in two experi-
ments;
16*5 grains, corresponding to carbonate of potash 45*3 in 100

16-9 46-3

Carbonate of potash 45*8 in 100

Solvent Action of Muriate and Nitrate of Ammonia. 33 S

Together, the result is, for 100 parts,

Cyanide of f)()tassium 53*4

Carbonate of potash 45*8

99-2
Loss '8

— a result confirmatory of sodium being present in small quan-
tity.

That the salt contained no caustic alkali was thus proved.
Into a weak solution of the salt, a solution of nitrate of silver,
likewise weak, was dropped. The precipitate was white, as
would occur from a solution either of cyanide of potassium or
of carbonate of potash. Into a similar solution of the salt,
one or two drops of a weak solution of caustic potash were
let fall, and, afterwards, one drop of the nitrate of silver solu-
tion; whereupon the light grayish brown, indicative of the
precipitation of oxide of silver, at once appeared. The ab-
sence of this light grayish brown in the previous experiment
demonstrated the absence of caustic potash or caustic soda in
the salt under examination*.

Marischal College, March 18, 1837.

LXIV. Further Experiments on the Solubility of certain Me-
tallic Oxides and Salts i?i Muriate and Nitrate of Ainmonia,
By R. H. Brett, Esq., F.L.S.

QINCE publishing my paper in the February Number of
^ the Philosophical Magazine, p. 95, I have made further ex-
periments on the same subject, the results of which I now offer
for insertion at this time, more especially since a recent criti-
cism has appeared, p. 1 78, not at all invalidating the accuracy of
the experiments, but complaining of what the author terms a
'' serious omission" likely to produce an erroneous opinion
as to the cause by which certain metallic oxides and salts are
brought into solution under certain circumstances. My ob-
ject, in the paper to which I have alluded, was to state certain
facts, which 1 believed to be of considerable importance in
chemical analysis, and an ignorance of which must lead to se-
rious errors, especially in certain quantitative investigations.
Your correspondent disapproves of the term soluble in muriate
or nitrate of ammonia, and had I expressly stated that such
solution Uikes place in every instance, without decomposition
of the ammoniacal salt employed, I should doubtless have
committed a grave error; such, however, was never my belief,
and the exact nature of the changes which took place, was-

• In reference to the subject of Dr. Clark's paper we may rite a notice
in Phil. Mag., First Series, vol. Ixii. p. 234.— Edit.

33i Mr. Brett^ sjurt/ier Ji„vpenments on the

not the subject of my inquiry; to find fault with the expression
is therefore, I think, rather liypercritical, as it would be in the
common expression that certain metallic bodies, such as zinc
or silver, are soluble in nitric acid; for any one using such a
term in reference to those substances would doubtless know
that before such solution could take place, the acid must un-
dergo decomposition. The experiments which I performed,
as well as a repetition of those referred to in my last paper as
instituted by M. Vogel, and afterwards by Mr. Smith, could
not but have informed me of the fact that the ammoniacal salt
does under certain circumstances, if not in all cases, suffer de-
composition.

1 shall now briefly mention the results of my late experi-
ments on this subject. The oxides and salts operated upon
were well washed on filters with distilled water, and allowed
to dry at the temperature of the room.

BaryticSalts, — The carbonate and phosphate of baryta, when
digested in cold muriate of ammonia in solution (a saturated
solution), yield a fluid which, after filtration, contains the earth
in some form of combination, it being readily precipitated by
dilute sulphuric acid: ammonia in excess causes no precipitate.

Strontian Salts, — Precisely the same results were obtained.

Lime Salts, — The neutral phosphate of lime which possesses
a semi-crystalline appearance, and was obtained by adding a
neutral solution of phosphate of ammonia to a solution of
chloride of calcium in excess, as also the subphosphate, al-
together devoid of crystalline structure, and obtained by add-
ing an excess of the salt of lime to the phosphatic salt, con-
taining, according to Berzelius, 1 and ^ more lime than the
neutral salt*, when digested in the cold with the saturated so-
lution of muriate of ammonia, yielded by filtration a fluid
which was abundantly precipitated by oxalate of ammonia,
and therefore contained lime in some form of combination.
It may be observed that ammonia added in excess to the fil-
tered fluid obtained by digesting any of the above salts,
barytic, strontian, or calcareous, did not cause any precipi-
tate.

Magnesian Salts. — The carbonate and ammoniaco-magne-
sian phosphate are similarly acted upon.

Oxide and Salts of Cadmium. — The oxide, carbonate, phos-
phate, and oxalate ofcatlmium, when digested in a cold satu-
rated solution of muriate of ammonia, yielded a fluid by filtra-
tion, abundantly precipitated of a yellow colour by hydrosul-
phuret of ammonia.

Salts of Cobalt, — The carbonate and phosphate when di-

* Berzelius, Traitc de Chbnic, torn. iv. p. 71 et scq.

solvent Action of Muriate and Nitrate of Ammonia, 335

gested in a cold saturated solution of muriate of ammonia
yielded, by filtration, a fluid abundantly precipitated of a black
coli)ur by hydro-sulphuret of ammonia.

Oxide and Salts of Manganese. — The brown coloured hy-
drated deutoxide of manganese when digested in the ammo-
niacal salt yielded, by filtration, a fluid which was precipitated
by hydrosulphuret of ammonia, of the peculiar pale flesh-
colour characteristic of salts of manganese ; it is not impro-
bable, however, that the oxide operated upon, although ap-
J;)arently of a uniform brown colour, might have contained a
ittle protoxide which had not passed into the state of deut-
oxide by aerial exposure. Phosphate of manganese when
treated in the same manner yielded, by filtration, a fluid which
was similarly acted upon by hydrosulphuret of ammonia.

Oxide and Salts ofCojypcr. — The hyd rated peroxide of cop-
per, the black anhydrous peroxide, and the carbonate of cop-
per, when digested in cold muriate of ammonia yield, by fil-
tration, a blue coloured fluid, evidently containing the metallic
oxide in some form of combination.

Salts of Bismuth, — The subnitrate of bismuth of the shops,
when digested in a cold solution of muriate of ammonia or
boiled in the same salt did not yield, by filtration, a fluid which
yielded a black precipitate by hydrosulphuret of ammonia;
the same may be said of the salt when recently precipitated, well
washed and dried at the prevailing atmospheric temperature.

The same applies to the protoxide and certain protosalts of
tiri.

Salts of Silver. — The chloride, carbonate, and phosphate
when prepared without exposure to light, and digested in the
ammoniacal salt, without exposure to light also, yielded, by
filtration, a fluid v*hich was precipitated black by hydrosul-
phuret of ammonia.

Persalts and Oxide of Mercury. — The peroxide, carbonate,
phosphate and bin iodide, when digested in a cold solution of
muriate of ammonia yield a fluid, which is abundantly preci-
pitated of a black colour by hydrosulphuret of ammonia.

Some other metallic oxides and salts still remain to be
operated upon ; but as circumstances prevent me from car-
rying on the inquiry at the present moment, I must defer the
consideration of them to a future period.

March 2, 1837- R. H. Brett, F.L.S.

N.B. It will be observed that the results arrived at with
the salts of bismuth are different from those mentioned in
the former paper, p. 98; but it must be remembered that they
were operated upon under different circumstances as then
noticed.

[ 336 ]

LXV. On the Laws of Trafismission of Light and Heat in
una-ystallized Media. By P. Kelland, B.A.^ Fellow and
Tutor of Queen's College, Cambridge, afid Member of the
Cambridge Philosophical Society.^

T^HE difficulties under which a mechanical theory labours
-■ must necessarily be owing, in the outset, to a view of the
subject not sufficiently simple. In the memoir \ from which
the following pages are extracted, I have endeavoured to re-
duce the equations of motion of a series of particles trans-
mitting vibrations, to the most simple possible Ibrm ; and from
that form to deduce, conversely, conclusions with respect to
the action of the particles themselves. Whether indeed a more
general form of the solution of the resulting equations may
not be the correct one, is another question, which I have dis-
cussed in a memoir lately presented to the Cambridge Philo-
sophical Society. It would be out of place again to give a
historical view of the subject, as it has been ably done by Pro-
fessor Powell, in his " Abstract of M. Cauchy's ViewsJ." I
have satisfied myself with developing my views as briefly as
I can.

In order to reduce the investigation to the simplest possible
form, I will suppose the particles symmetrically arranged with
respect to the three coordinate axes, and conceive the trans-
mission to take place along one of these axes, that of x. It
is clearly requisite that such an hypotliesis should be made
when we treat of media not crystallized.

Let X, y, z be the coordinates of the particles P under con-
sideration : when at rest

x-\-lx, y-^ly, ;s-\-lz those of Q.
r the distance P Q,
i^nd at the end of the time t, let

x-\-a, 3/ + /3, sf+y be the coordinates of P,
x + a + ^^ + ^a> 3/ + /3 + ^y + a/3, ^ + 7+82 + ^7 those of Q,
r + g the distance P Q.
.Also let (r <^{x)) represent the attraction at the distance r.

Then denoting by the symbol X the sum of all functions si-
milar to that which follows that symbol, we have

= X<^(r + Vi{Zx-^la).

dt'

• Communicated by the Author.

t Transactidns of the Camb. Phil. Society, vol. vi. part 1.
t This abstract will be found in Lond. and Edinb. Phil. Mag. vol. vi.
p. ]6 ^/ seq, — Edit.

Transmission of Light and Heat in uncrystallized Media, 337
By expansion we obtain

d ^r
^{r + q)=:^{r) + -^?+

and {r^qf = (8.r+d^a)^+ (5y + ^/3)^ + (8^ + §yr

,*. q = — (S a: S a + S^ § /3 + ^' 2; S y) omitting small quantities ;
and by substituting this value in the above equation, it gives

but -5* <^ r . S .r is evidently the accelerating force, resolved pa-
rallel to x, on the particle P in its state bf rest, and conse-
quently is equal to zero: we have then

which we will call equation (I.).

I shall pass over the argument for the^rm of the solution,
and assume at once that

ex, = a cos (nt—kx)

^ = b cos {n' i—kx)

y = c cos {n" t—kx)

the quantity k being the same for all, as it is the ratio ;

A

A being the length of a wave. We shall thus obtain,
8a = fl cos {nt— k x—k^ x) — a cos nt — k x

= a cos(n t—kx) Q.osklx-\-a sin nt—kx ^xnklx

— a cos {nt—kx)

k ^x
= — 2acofi{nt—^x) sin^— ^— + asin(«/— ^j?)sinA:5^

= — 2 a sin^ ^ h a sin {nt—k x) sin ^ 8 ^

k^ X
8|3 = — 2/3 sin® — ^— + b sin {n' t—kx) sin A: 8^

8 y = — 2 y sin® — 1- c sin {ril' t—k x) sin kl x.

Now we have supposed the medium to be one of symmetry:
to fix the ideas, conceive the particles arranged in a cubical
form, the edges of the cube being parallel to the coordinate
axes. Hence for every value of 8 jt there is a set of j)airs

ThirdSeries, Vol. 10. No. 62. May 1837. 2 X

338 Mr. Kelland on the Laws of Transmission

of values of dy equal in magnitude, and opposite in sign: the
same is true of values of 8 : the sum of all such expressions
is consequently equal to zero.
• Making all the reductions, the equation (1.) is finally re-
duced to

di^ \ rdr J 2 '

and by exactly the same process the foUovv^ing equations result
for the other directions :

jt = -2r^|^M +7;^ 5^7sm^ ^-.

These equations it must be observed have resulted from
the hypothesis that their solution has the form

a = a cos {nt—Jcx)
&c.

—7-^ = -^ a n^ cos hit— k x)
dt^ ^ ^

= — w^ a ; y

hence n^ = 2:S l^r + -^^ Sjc^ Vsm^ -^--j

&c. &c.

and if v^ ty', t/', be the velocities of transmission of disturbances,
parallel respectively to x, y and si, v/e evidently have

k
.;-^=2:r(^r+^^8.^)(sin^-)

I forbear to mention in this place, the facilities which are
afforded by these equations to the explanation of dispersion,
my object being the especial one of pointing out the reasoning
by which we are led to the assumption of the inverse square
(yftlie distance as one law of force.

It will be evident to any one who attentively studies the
above equations, that the expression for the square of the ve-
locity of transmission is a series of terms beginning from

of Light and Heat in wicrystallized Media. 339

zero, and increasing from that value until Ix becomes equal to
-T- or — -, then diminishing till 8 x becomes X, afterwards in-
creasing and diminishing in the same manner.

And further, if the force vary according to an inverse power
of the distance, or to a function which can be expanded in
inverse powers, the terms introduced by the successive half-
waves will diminish rapidly; the whole value of the square of
the velocity will then depend essentially on that term which
depends on the first halt-wave.

For this term let us expand the sine and omit the other
terms; or rather suppose this one to represent truly the Jbrm
7, and we obtain the following expression :

and similar expressions for v'^ and t/'^

Now suppose <^ {?') = -fnji or that the force varies as the

inverse wth power of the distance : then , = — — . ^ and
if g be the distance between two consecutive particles, and

we shall have

iH

s-H-l ,yi , ..a . »^^'Hll

n+ie

»±.}{^^^-S?*^^}

»i-f-3

P L. i_

}^{^-S*^}

As we are not able to integrate or sum the above series di-
rectly, we are obliged to make some hypothesis respecting it ;
the most obvious appears to be that which we have adopted,
p and q being numerical factors.

The velocity with which light is transmitted is greater in
vacuo than in refracting media, whilst no perceptible variation
of velocity is occasioned by the different lengths of waves.

2X2

S40 Mr. Kelland on the Laws of Transmission
The same circumstance, therefore, which increases -^^ dimi-
nishes — ^

=11—3

Now if w— 1 and w — 3 had both the same sign, an increase
in s would increase or diminish both the above quantities at
the same time; and a Hke effect would result from a diminu-
tion of e.

We must therefore have one positive and the other nega-
tive; which can only be effected by supposing n to be either a
fraction, or equal to 2: the latter supposition is the more
probable, and we shall presently see additional reasons for
supposing it the true one.

Again, since the velocity is greatest in vacuo where the va-
riation of velocity is least ; it follows that s must be less or the
density of the other greater in vacuo than in refracting media.

By substituting this value of the law of force, we obtain

sm^

2 r^ A

= T^^ ^ ^^"^^•

But :,i|!sin^^ = ^i|!sin^^,

r^ k IT K

from the symmetry of the medium

1 ^2ly^-%lx^ . ^%lx

= X -•^— , sm*——

^ =-2-^ W—^ ^^"-IT

sin^^

Similarly

=

1

2

X-

=

—

1
2

x^.

t/^ =

—

1

2

^%

of Light and Heat in uncrystallized Media, 341

from which it appears that of the three disturbances either
one gives rise to a vibration, and two do not, or vice versd.

Let us then examine the circumstances which will deter-
mine each of these results respectively.

We have conceived that the action of a particle in advance
of the given particle is to draw it forwards, which is in fact
supposing the force attractive.

Now, V =i X, -^ — IT sm^ -- — ,

where r', Sjt', sy, are partictdar values of the unaccented
quantities.

Now, for every value of 8 y' there is a corresponding value
of Ix' equal in magnitude, and the term in the series will
therefore be ^

S pj sm -^,

8y being now a particular value of ix', and so on.
Hence v^ consists of the sum of a series of the form

:, { ?i^!=i^sin« 4^ + ^^:!=ii^%in' '4^}

= 2Vr»^^(sin^^-sin^^).

And, restricting ourselves to the same limits as before, if lyf

be greater than 8 x' sin^ — -^ is greater than sin® ^ and

the above expression is clearly negative. Also it is perfectly
evident, from what we have before observed, that the sign of
the whole will be the same as that from the particles within
the range of the first half-wave.

Hence v^ is negative, or a vibration in the direction of
transmission impossible : and since t^^ = v"^ = — ^v\ the
vibrations which result from disturbances perpendicular to
the direction of transmission are transmitted with the same
velocity whatever be the direction of disturbance.

Hence the vibrations in a medium exerting attractive forces,
varying according to the inverse square of the distance, are
, necessarily transversal.

In the same manner it may easily be shown that were the
force repulsive, the particles must vibrate in the direction of
transmission. Of the last conclusion, that repulsive forces give
rise to direct, and attractive forces to transverse vibrations, I
have offered a popular explanation as follows :

" A series of repulsive particles constituting any vertical

342 Mr. J. Barton on the Physical Causes

line being simultaneously impelled in a horizontal direction,
would, by virtue of their repulsion, cause a similar motion in
those immediately in front of them, whilst the latter particles
would tend to check the impetus of the former, and thus vi-
brations in the direction of transmission are simple to con-
ceive and easy to explain. But suppose the forces attractive.
Let the system of particles in a vertical line have a vertical
motion, and the slightest consideration will show us that the
immediate consequence is the production of a vertical motion
in the particles immediately in advance of them ; whilst, as
before, the reciprocal action of the latter particles tends to
impede the motion of the former. Here, then, we have as
clear a case as before, and our general conclusion from the
whole is, that repulsive forces allow of direct, attractive of
transversal, vibrations only." — (Trans. Camb. Phil. Society,
vol.vi.. Parti., p. 178.)

The three equations of motion will then finally be reduced
to the form

dt^
dt^

= + 2c^

= - c^/3

d^y _ _

dt

= — C^y.

The first of these I have developed in a paper read in May,
seeing reason for its application to the phsenomena of heat.

[To be continued.]

LXVI. On the Physical Causes of the principal Phcenomena

of Heat, By John Barton, Esq,^
TT has always appeared to me that the corpuscular hypo-
thesis is capable, with some modification, of affording a
more complete and satisfactory explanation of the phaenomena
of heat and light than the undulatory hypothesis. On the
present occasion I propose, without entering into any contro-
versial discussion, to show in what manner the principal phae-
nomena of heat may be deduced from the action of two forces.
An attractive force between the particles of heat and those of
solid matter, a repulsive force between the particles of heat
themselves.

I assume that the particles of heat are very small in com-
parison of the particles of solid matter, and that these last are
very small in comparison of the intervals by which they are

* Communicated by the Author.

of the priiicipal Phcenomena of Heat, S4S

separated from each other. The phaenomena also require
that the repulsive force should decrease more rapidly than
the attractive force. These premises being admitted, the fol-
lowing consequences may, if I do not mistake, be deduced
from them. For brevity's sake I omit the demonstrations,
presuming that they will be readily supplied by those versed
in mathematics.

1. If a particle of heat approach a particle of solid matter,
it will either fall to the surface and remain there, or it will
describe a curvilinear orbit thereabout. According to the
direction and velocity of its approach, this orbit will either be
confined within a certain limit, like an ellipse, or will go off
to an infinite distance, like an hyperbola. To avoid circum-
locution, I will take leave to call these two classes of curves
respectively, ellipsoidal and hyperholoidal curves. A particle
of heat reposing on the surface of a particle of solid matter,
or revolving about it in an eUipsoidal curve, will have no ten-
dency to fly off or to pass into a contiguous body, unless dis-
turbed by some exterior force. It is therefore latent.

It must not be supposed that latent heat exists only in fluid
or gaseous bodies. The phaenomena of softness and mallea-
bility must be considered as resulting from the presence of a
portion of heat in this state. Nay, it is probable that even
the hardest and most brittle substances are not entirely de-
prived of it.

2. When a solid body is exposed to friction or percussion, a
certain number of the particles of heat which had evolved tran-
quilly in ellipsoidal curves are forced out of their orbits, and fly
off beyond the reach of the attractive force of the particle to
which they belonged ; just as our earth might be driven out
of the limits of the solar system by the stroke of a comet; sup-
posing the latter of sufficient density and magnitude. And
thus we have an explanation of the heat produced by friction
or percussion ; which has been supposed to form one of the
strongest objections to the corpuscular hypothesis.

It confirms this theory, that a piece of iron which has been
heated by hammering becomes brittle^ indicating that a por-
tion of its latent heat has been lost, while sensible heat has
been disengaged.

3. If we suppose a particle of matter to be of an oblong
form, or to have one of its axes greater than the others, the
particles of heat will collect chiefly about the middle of its
length. And thus we have an explanation of a remarkable
fact discovered by M. Mitscherlich, that crystallized bodies,
when heated, do not expand equally in all directions*.

* See Phil. Mag., First Series, vol. Ixiy. p. 162; and Lond and Edinb.
Phil. Mag, vol. i. p. 413.— Edit.

34?* Mr. J. Barton on the Physical Causes

4. When the coefficients of the attractive and repulsive
forces bear a certain relation to each other, and to the original
velocity of approach, the orbit described will resemble a con-
choid^ its two branches being ultimately in one and the same
line. In this case the body is diathermanous, the rays of heat
passing through it apparently in a straight course. The course
of a ray through a solid body can never be in fact straight,
unless its velocity be infinite ; but in proportion as the velo-
city approaches this limit, the ray will experience less disturb-
ance in passing through bodies imperfectly diathermanous.
And accordingly it is found, that rays from incandescent bodies
pass through some media which do not admit the passage
of rays issuing from bodies of lower temperature, the velocity
of projection evidently depending on the repulsive force ; and
this, in its turn, on the temperature.

5. It must not however be supposed that opake or adiatlier-
manous bodies are impervious to the rays of heat. They differ
from transparent or diathermanous bodies only in this, that the
entering ray, instead of passing through immediately, and
escaping from the opposite side, is entangled in a circuitous
and irregular course among the particles, until by chance
it reaches the surface, when it escapes, unless the angle of its
direction with the tangent be so small that it is drawn back
again by the attractive force. A particle of heat is therefore
detained much longer in passing through an opake than
through a transparent body, and contributes much more to
raise its temperature, and hence it also appears why the pas-
sage of heat through opake bodies is very much slower than
through transparent media.

6. The particles of solid bodies are drawn towards each
other by two forces, their mutual attraction, and their attrac-
tion for the atmospheres of heat about the others. They are
also kept apart by two forces, the mutual repulsion of those
atmospheres of heat, and the repulsion of the particles of free
or sensible heat, which happen at the time to be passing be-
tween them. As long as the number of these last remains
unchanged, the balance of the opposing forces is a balance of
stable equilibrium, in as much as the attractive force dimi-
nishes with the distance in a less ratio than the repulsive
force. If the number of particles of sensible heat is increased,
the body dilates till the equilibrium is restored ; but if this
dilatation proceed to a certain point, the orbits of a cer-
tain number of the revolving particles of heat will be changed
from the hyperholoidal to the ellipsoidal form ; that is to say,
a certain quantity of sensibly heat will be converted into latent
heat. At the same time another portion of sensible heat will
be acquired from the surrounding bodies and the united re-

of the principal Phcenomena of Heat. $4.^

pulsive force of these two portions of heat will overbalance the
forces of attraction. Thus we have an explanation of the phse*
nomena of vaporization.

An account of thfe causes of this last class of phaenomena
somewhat resembling the above has been given by Laplace
in the twelfth book of the Mecanique Celeste. Laplace how-
ever gives no explanation of the difference between latent and
sensible heat : he attributes the phaenomena of expansion ex-
clusively lo sensible heat, but does not explain why heat when
it becomes latent should lose its repulsive force : he supposes
the particles of heat to form atmospheres about the particles
of solid matter, which are at rest unless disturbed ; and in
order to explain why sensible heat tends continually to fly
offi he supposes the particles of matter to l)e in a state of con-
tinual agitation.

7. In the same chapter Laplace has given an explanation
of the phaenomena of liquefaction, which appears to me to
require modification. " Every molecule of solid matter," he
says, " is subjected to the action of three forces : 1st, the attrac-
tion of the surrounding molecules ; 2ndly, the attraction of
the caloric of those molecules, plus their attraction for its ca-
loric ; Srdly, the repulsion of its caloric by the caloric of those
molecules. The first two forces tend to bring the molecules
nearer together, the third tends to separate them. The three
states of solidity^ fluidity^ and gaseous elasticity depend on the
respective efficacy of those forces. In the state of solidity, the
first force is the most powerful ; the influence of the figure of
the molecules is very considerable, and they are united in the
direction of their greatest attraction. The increase of caloric
lessens this influence by dilating the body; and when this
increase is such that the influence in question is very small or
none, the second force predominates, and the body takes the
liquid form."

I am unable to comprehend why the attractive force be-
tween two solid particles should be suddenly reduced to
nothing when they are separated to a certain distance one
from the other. And this suggestion appears still less pro-
bable when it is considered that many crystallizable bodies
cease to contract, and even undergo a degree of expansion,
at the moment of congelation. The act of changing from
fluid to solid depends then on some other cause than the ap-
proximation of the particles. Laplace has, I think, truly as-
signed the immediate physical cause of solidity, when he says
that in solid bodies the particles are placed relatively to each
other in the position of greatest attraction ; but he has not
given an adequate reason for their assuming this position. To

Third Series. Vol. 10. No. G2. May 1837. 2 Y

346 Mr. J. Barton on the Physical Causes

supply this deficiency, it may be useful to revert to an expla-
nation above given of an observation of Mitscherlich^ on the
unequal expansion of crystallized bodies in different directions*
It was suggested that the particles of heat do not accumulate
equally round every part of a particle of solid matter if its
axes are of unequal length. Now, this inequality of distribu-
tion is such, by the nature of the case, as to counteract the
tendency of the particles to place themselves in the position
of greatest attraction. In other words, the compound force
exerted' by the central solid nucleus, with its surrounding at-
mosphere of heat, will approach more and more nearly to that
of a sphere as the heat increases ; and by consequence the
figure of the particles exercises a less and less influence on
their mutual position. When that influence. is completely
neutralized, the body is a fluid.

8. As the mutual attraction of the particles is not however
destroyed in fluids, these particles still arrange themselves in
the position of greatest attraction.. But this position is no
longer influenced by their figure; it is now such precisely as
would be assumed by them if spherical, that is to say, the
position in which the distance of their centres is a minimum.
Now this is the position in which the sum of the intensities
between them is also a minimum ; therefore the whole bulk
of the fluid just before congelation is a minimum. If we sup-
pose other forces to come into operation, those, for instance,
resulting from the figure of the particles, the dimensions of
the body will consequently be enlarged ; and thus it appears
why so many substances are found to expand in the act of
congelation.

9. Further, as the position of greatest attraction amongst
the particles of a solid is that in which their salient angles are
presented towards each other, it follows that at the moment
of solidification, when this arrangement is established, the
orbits of a certain portion of the accompanying particles of
heat will be changed from the ellipsoidal to the hypei^boloidal
form ; that is to say, a certain quantity of latent heat is con-
verted into sensible heat.

10. Those solid bodies which are composed of the largest,
or rather the heaviest particles, are at once the best con-
ductors and the w orst radiators of heat ; for the velocity in-
creases with the mass. Hence the metals are the best con-
ductors of heat, and as far as the experiments hitherto made
enable us to judge, their conducting power seems to follow
the same order with the magnitude of their component atoms,
the differences not being greater than may be reasonably sup-
posed to arise from errors of observation. For a similar rea-

of the principal Ph(snomena of Heat, 347

son a particle of heat attempting to escape from the surface of
a metallic body is more strongly drawn back by the attractive
force of the particles than at the surface of other bodies.
The metals have therefore less radiating power than any other
substances.

11. The particles of heat emerging from the surfaces of solid
bodies at angles so small as to be drawn back again into their
substance, form collectively an atmosphere enveloping those
surfaces, and extending, there is reason to believe, to distances
considerably greater than the interval which separates the
solid particles from one another. It is to this atmosphere
that we must attribute the repulsive power exerted at the sur-
faces of bodies, metallic bodies especially, by virtue of which
mercury is depressed in a barometer tub^, and a steel needle
floats on the surface of water. By strong pressure this en-
veloping atmosphere may be expelled from between two me-
tallic surfaces, and the attractive force of their particles then
coming into play, they adhere with considerable force. The
reflexion of heat at the surfaces of bodies also appears to be
due to the action of this enveloping atmosphere.

12. It may facilitate the apprehension of my meaning to
observe, that a particle of matter, with its revolving particles of
heat, is supposed to have a resemblance to the sun, with its
accompanying bodies, in the solar system. The planets, re-
volving in elliptic orbits, represent the particles of latent heat ;
the comets, if indeed any of them revolve, as formerly sup-
posed, in parabolic or hyperbolic orbits, represent the par-
ticles of sensible heat. Future observations will, perhaps, en-
able us to determine the law of the forces by which these minute
movements are regulated, as accurately as we are now ac-
quainted with the law of gravitation. The preceding conclu-
sions are, however, independent of the particular law of those
forces.

January 27, 1837-

P.S. I have assumed, in conformity with the views of La-
place and other mathematicians, that the particles of solid
matter mutually attract each other. But the preceding con-
clusions hold good though no such force of attraction exists,
or even if we suppose with iEpinus that the particles mu-
tually repel each other, a supposition which is by no means
incompatible, as Dr. Roget has observed*, with the phaeno-
mena of gravitation. There are certainly strong reasons in
support of this last hypothesis.

* See SciENTinc Memoibs, Part III. p. 469.— Edit.
2 Y2

[ 348 ]

LXVIL On the Composition and Origin qf^ Porcelain Earth,
By Henry S. Boase, M.D.^ Secretary of the Royal Geolo^
gical Society of Cornwall, <^c,^

"LT AVING lately seen in the Annates de Chimie et de Phy-
-*■-*■ sique (torn. Ixii. p. 225.) an interesting paper on Kaolin
by Berthier, the conclusions of which, however, do not seem
to me to be perfectly satisfactory, I am induced to offer a few
remarks, together with an account of some experiments on
the Cornish kaolin, in hopes of calling attention to this cu-
rious but complicated problem in " the chemistry of geo-
logy."

Berthier commences by observing that in a former analysis
he found the kaolin of Limoges to be composed of

Silica 46-8

Alumina 87*3

Potassa 2*5

Water .* 13*0

99-6
The presence of the alkali he attributed to a mixture of un-
decomposed felspar; and this being deducted, he considers
that the remaining pure plastic clay is a silicate of alumina, re-
presented by the formula AS + Aq, as also given by For-
chammer for the porcelain earth of Bornholm. But by a re-
cent set of experiments Berthier has found a considerable
portion of magnesia in kaolin from various localities, as shown
by the following analyses of the pure argillaceous parts, pre-
viously separated from the intermixed substances, by the suc-
cessive application of sulphuric acid and of a solution of po-
tassa.

Limoges. Pamiers. Elbogen. Dept. de TAllier.

Silica 43-05 45' 61-4 56'

Alumina 40*00 38* 23*2 37*

Magnesia ... * 2*89 1*2 0*5 much

Water 14*06 11*7 13*8 12*3

100* 95*9 98-9

These specimens of kaolin, with the exception of the first,
do not appear to have been well prepared ; indeed, even the
clay of Limoges cannot be compared with that of Cornwall,
since it contains from 20 to 25 per cent, of an undecomposed
mineral ; whereas the largest quantity which I have obtained
from good Cornish samples is under 10 and as low as 8*5 per
cent.

* Communicated by the Author.

On the Composition and Origin of Porcelain Earth. 349

The substances which Berthier separated from kaolin are
granules of quartz and minute white or yellowish-white scales
having a pearly lustre. The composition of the scaly mineral
he ascertained to be as follows :

Limoges. Pamiers. By calculation.

Silica 65-9 59-2 67-7

Alumina 20*8 25'2 19-1

Potassa 7'5 ... 9*8

Soda 8-9

Magnesia 2-8 0*5 3*4?

Lime 1*9

Water 1-0 3*2

98* 98'9 100-

This mineral Berthier regards as the peculiar felspar from
which the kaolin has been derived by decomposition. He
has taken some pains to establish this point; and has at-
tempted by calculation, founded on the above analyses, to give
the true atomic composition of this supposed felspar. I am,
however, inclined to think that he is mistaken : for the unal-
tered mineral which I have extracted from the Cornish kaolin
is decidedly a variety of talc, in an extreme state of commi-
nution, and its appearance under the lens exactly agrees
with that described by Berthier. Now this mineral abounds
in the talcose granite, or protogine, which by disintegration
furnishes the beds of porcelain clay ; but it does not experi-
ence any change, remaining in the clay, from which it is se-
parated in considerable quantity during the process of prepa-
ration for the potteries. It seems to be nacrite or scaly talc of
mineralogists, of which Vauquelin has given an analysis, nearly
approximating to that of the scales from Pamiers as above
quoted.

In denying that kaolin has been formed, from the scaly mi-
neral with which it is intermixed, I am willing to admit that
it has been derived from a potasso-magnesian felspar which
may be similar in composition to that indicated by Berthier's
calculation. Indeed several years ago I suggested, on minera-
logical considerations, that the felspar of protogine probably
contains magnesia. This conjecture is now confirmed by the
detection of this earth in kaolin ; and I have since ascertained
that it is also present in the china-clay of Cornwall.

The specimens examined were of the best quality from
Breage and St. Stephens. The process which I adopted was
very similar to that employed by Berthier, and gave the fol-
lowing results.

550 Dr. Boase on the Composition and

Breage. St. Stephens.

Silica 40-15 39*55

Alumina 36-20 38-05

Magnesia 1*75 1*45

Water 11-65 12-50

Insoluble residue 1 ^^ ^r. o ►r/v

(quartz and talc) |_^ ^

99-25 100-25

The circumstance most to be noted in all the analyses of
kaolin hitherto made, is the great discrepancy in the results,
which is unavoidable, because this substance is necessarily he-
terogeneous, quartz and talc being mixed with the silicate
of alumina in variable proportions, even when washed with
the greatest care. Berthier's process will show pretty nearly
the quantity of silicate in the kaolin ; but it includes two sources
of error, for some alumina will escape between the scales of
the talc, and some quartz will be dissolved by the alkaline so-
lution. If, however, the earthy salt be completely separated,
this does not indicate the actual composition of kaolin as an
article of commerce, for the talc and quartz are not prejudicial
to it ; indeed protogine itself, under the name of china-stone^
or petuntze, is ground and mixed with the porcelain-earth at
the potteries.

I would also remark that the paper of Berthier, acceptable
as it is as an analytical essay on an interesting subject, affords
another instance of the great bias which the atomic system
gives to reduce experimental numbers according to this Pro-
crustean rule. Thus the kaolin is found to contain potassa ;
this is acutely referred to the presence of an unaltered mineral,
proved by analysis to be the source of the alkali. But then
its constituent parts, as obtained by experiment, are respec-
tively drawn out or cut off, in order to suit the calculated
composition of a potasso-magnesian felspar ; and the evil has
not stopt here, for the constituents of the kaolin are altered on
the same data ; and on these also it is attempted to explain
the nature of the process by which kaolin is produced from
felspar.

1 now proceed to notice the perplexing problem concerning
the formation of porcelain-earth.

Some have supposed this clay to be an original production,
or rather a friable deposit from which the subjacent crystalline
rock is now in progress of reconstruction. It is, however, at
the present day generally admitted that it owes its origin to a
chemical change effected in various kinds of felspathic rocks ;
but the precise nature of this change is yet unascertained.

Origin of Porcelain Earth, 351

Werner was tlie first to attribute it to the action of water
containing free carbonic acid, by which the alkaH of the felspar
is gradually abstracted. This opinion prevailed among chemists
until Berthier showed that silica is also carried off dissolved
in the alkaline solution, leaving a silicate of alumina, the con-
stituents of which are consequently not in the same proportion
as in felspar.

The late Dr. Turner has illustrated this subject in a very
clear and pleasing manner, (Philosophical Magazine for July
1833,) explaining the change by the following formula:
Felspar. Porcelain-earth.

(Po + 3Si) + (Al + 9Si); (Al.+ 3iSi).

The potassa is first set at liberty by the action of water and
carbonic acid, and the composition of the felspar being thus
subverted, the silica whilst in a nascent state is dissolved by
the alkaline solution with which it is in immediate contacts
" The formula," says Dr. Turner, " showed that every two
equivalents of alumina present in porcelain clay along with
three and a half of silica, corresponded in the original felspar
from which it was derived, to twelve equivalents of silica and
one of potash. Hence the quantity of silica carried off was
enormous."

The process of decomposition from which kaolin results has
also been well described by Fournet as quoted by Becquerel
{Traite de VElectricite etdu Magnetisme^ tom. i. p. 503), who
has collected much interesting information on this subject.

" ' Le feldspath, quand il est desagrege et terreux,' dit M.
Fournet, ... 'absorbe done Tacide carbonique, qui reagit sur les
silicates et s'empare de leur bases les plus fortes. La silice est
mise en liberie a un etat gelatineux qui lui permet de se dis-
soudre en certaine quantite, a la verite, dans les eaux et dans
les carbonates alcalins ; elle est alors entrainee par elles, et
donne naissance, suivant les circonstances, a des cristaux de
quartz hyalin, des fiorites, des agates, des opales, des concre-
tions calcedoines, et des silicates de nouvelle formation, telles
que les mesotypes, les chabasies, &c.'"

These explanations are consistent with our present know-
ledge of chemistry; but they rest too much on induction, and
not on actual experiment. For, in the first place, before the
precise nature of the decomposition can be determined, it is
necessary to ascertain the composition of the felspar ; and I am
not aware that this has ever been done. At all events, the
felspar in the foregoing formula (which indeed is the one
usually referred to on this subject) is the mineral which enters
into common granite and not into protogine. And since these
rocks occur passing gradually into each other in alternating

352 On the Composition and Origin of Porcelain Earth.

series, not only in Cornwall, but also in the Alps and in the
Vosges, and are situated under precisely the same circum-
stances, the fact that the one is decomposed to a hundred times
the extent of the other would alone point at a difference in
the composition of the felspar of the respective rocks. This
is now, in some measure, established by the foregoing analyses
of kaolin. It is, however, desirable that the felspar of the pro-
togine should also be examined, though it will not be easy to
procure a proper specimen for this purpose ; and the chemist
must be cautious in his selection of one, that he does not take
it from the micaceous or shorlaceous granites with which the
protogine is associated.

We have yet so much to learn concerning the properties of
alumina and its combinations, that it is difficult to give a satis-
factory account of the changes which occur even during the
decomposition of common felspar. It is generally supposed
that the alkali is first set at liberty and then acts on the nascent
silica; but why not also on the alumina whilst in the same
condition, or on the silicate of alumina, and still more on the
alkalino-silicate of alumina, which is very soluble in alkalis
and is most probably present in disintegrating felspar ?

But supposing these difficulties surmounted, we have still
the first and fundamental change to account for, viz. the sub-
version of the powerful affinity by which the constituents of
the felspar are united. It is an easy matter to say that it is ef-
fected by the long-continued action of water and carbonic
acid, but what is the modus operandi! In the laboratory,
we cannot dissever the component molecules of this mineral
by the most powerful acids ; how then can the weakest effect
it in Nature ?

Berzelius has made some excellent observations on this sub-
ject, (Traite de Chimie, tom. iv. p. 574<,) instancing other sub-
stances, both natural and artificial,which resist solution in acids,
contrary to what might be inferred from the nature of their
composition ; and he concludes that the elements of compound
bodies do, in reality, combine in two distinct states of union.

Fournet, who has paid great attention to the difficult sub-
ject under consideration, is of opinion that the felspar must
be first disintegrated (desagrege) before the chemical action
can commence; and he conceives that this is actually accom-
plished in consequence of felspar possessing the property of
dimorphism, the new or second arrangement of the particles
causing the disintegration. Becquerel justly remarks on this
solution, that we have yet to learn that the particles of igneous
rocks, on consolidation, did not assume a permanent form ;
and that they have experienced by the lapse of time a change

Mr. L. Thompson on Antimoniuretted Hydrogen, 353

in their arrangement. It may also be added, that if felspar be
dimorphic, how comes it to pass that the granite (abounding in
felspar) in which the protogine occurs is buts lightly altered ?

It appears more probable that a difference in composition
in the felspars of these rocks will afford the true solution of
this problem, and though the data on which we can at pre-
sent reason are very imperfect, yet I am inclined to think
that the presence of magnesia in the felspar of protogine may,
among other causes, contribute toward the extraordinary
change which this rock experience/s. Thus, the magnesia may
absorb carbonic acid, as well as the alkali, from the percolat-
ing water ; and so great is its tendency to combine with two
proportions of this acid, that even one part of the carbonate
will attract the acid of the other, so as to pass into a bicar-
bonate of magnesia ; in which state being soluble in water, it
would be speedily removed. This in some measure explains
the origin of kaolin, and it also accounts for the small quan-
tity of this earth remaining in the porcelain clay ; indeed I have
examined some samples in which I could not detect a trace
of magnesia.

This subject is one of great importance to the geologist, as
affording an insight into a first and elementary step in the
mighty changes which the crystalline materials of the globe
have undergone; and the prosecution of this subject by che-
mists would confer a boon on geology, and at the same time
cannot fail to be instructive to themselves by leading to a better
knowledge of the combinations of alumina.

LXVIII. On Ajitimonmretted Hydrogen, mth some Remarks
on Mr. Marsh's Test for Arsenic, By L. Thompson, Esq.y

Member of the Royal College of Surgeons,

To the Editors of the Philosophical Magazine and Journal,
Gentlemen,
T BEG leave to direct the attention of your readers to a
-*- hitherto unnoticed combination of antimony and hydrogen,
which acquires great interest from its near resemblance in
many respects to arseniuretted hydrogen. The plan which I
adopt for procuring this gas in its greatest purity is by fusing
together equal weights of antimony and zinc, and acting on
the alloy with diluted sulphuric acid ; this process is not per-
haps altogether free from objection, but answers very well for
general purposes. As thus prepared antimoniuretted hydro-
gen is a colourless inflammable gas, exploding violently by
the electric spark or lighted taper when mixed with an equal
volume of oxygen, chlorine, or atmospheric air ; its odour is

Third Series, Vol. 10. No. 62. May 1837. 2 Z

354 Mr. L. Thompson oti Antimoniuretted Ht/drogen,

peculiar and approaches nearly to that of arseniuretted hydro-
gen ; inflamed at a jet in the open air it burns with a pale
bluish green flame resembling that of arseniuretted hydrogen,
and gives off" a dense white volatile vapour, which collects, as
a semicrystalline oxide, on cold bodies placed over it, affording
another instance of the similarity of these gases: when a piece
of cold glass or china is held in the flame a metallic crust is
deposited, and when a tube of glass is used, the metallic film
is formed on that part of the tube nearest the flame, and the
white oxide around and above it. It is unnecessary to add, that
these appearances coincide, in a very remarkable manner, with
those produced by arseniuretted hydrogen under similar cir-
cumstances ; and although a practised eye may discern some
difference between the crusts, that from antimony being more
silvery and metallic, yet the line of demarcation is not easily
drawn, for a thin film of antimony looks more like arsenic
than antimony, and a thick crust of arsenic has the metallic
appearance of antimony. When sulphuretted hydrogen is
passed over the oxides of these metals, the antimonial oxide
will become of a darker yellow than the arsenical; but this is
also fallacious, for a small quantity of antimony gives a yellow
not darker than orpiment, and if any metallic arsenic be pre-
sent in the arsenical oxide, a portion of realgar forms and
gives the product an orange hue. The ammoniaco-sulphate of
copper is liable to similar objections, for a large quantity of
the oxide of antimony produces a whitish green precipitate
which might easily be mistaken for Scheele's green. The two
metals may, however, be distinguished by adding a drop of
nitric acid to the crusts; they will immediately dissolve, and on
evaporating to dryness a white powder is left in each instance.
A few drops of a dilute solution of the nitrate of silver being
now added, and the whole exposed to the fumes arising from a
stopper moistened with ammonia, the antimonial solution will
be observed to deposit a dense white precipitate, whereas that
from arsenic will give the well-known Canary-yellow flocculi.
I prefer this mode of using silver to the ammoniaco-nitrate of
the same metal, for the slightest excess of ammonia destroys
the colour, but by watching the effect of the vapour, the exact
quantity requisite is easily obtained.

For the purpose of testing, it is unnecessary to use the alloy
which I have mentioned, as the gas arising from one grain of
tartar emetic, or any other salt or oxide of antimony, with a
little diluted sulphuric acid and zinc, will furnish an abundance
of metallic crusts; indeed a single drop of the common wine of
antimony will produce a very distinct film. In accordance with
the names already given to similarcompounds of hydrogen and
the metals, 1 have called this gas antimoniuretted hydrogen.

Mr. P. Cooper's Notice of a Theory of Molecular Actio7u 355

All circumstances considered, I fear we can only regard
Mr. Marsh's very ingenious test for arsenic as furnishing good
collateral evidence, capable indeed, in scientific hands, of giving
very correct indications, but wholly unfit to be entrusted to those
unaccustomed to careful chemical manipulation. 1 say this
with a thorough conviction of the great utility of Mr. Marsh's
test, and am only sorry that its evidence is not unequivocal.

Roebuck Place, Yours, &c., Lewis Thompson,

Great Dover Road. M.R.C.S.

LXIX. Notice of a Theory of Molecular Action.
By Paul Cooper, Esq,

To the Editors of the Philosophical Magazine and Journal.

Gentlemen,
¥ N the Philosophical Magazine for April, p. 320, you have given
"■■ a notice of the researches of M. Mossotti relative to the laws
of molecular action ; may I beg the favour of your directing
the attention of your readers to an equally simple and much
more comprehensive theory on the same subject, a sketch of
which I published in a small pamphlet* some months since?

"1. In this theory it is assumed, that bodies are formed of
matter, consisting of globular atoms of different sizes, having
an attraction for each other in the direct proportion of their
bulk, or quantity of matter, and inversely as the square of
their distance ; and of light, consisting of globular atoms,
constantly separated by a repulsive force, regulated by the
same law of distance, uniform in size, and much smaller than
the atoms of matter ; for which they have an attraction, also
regulated, both with regard to distance and dimensions, by
the laws already mentioned.

" 2. The light under the influence of these laws must sur-
round the atoms of matter, forming what we have called an
atmosphere about each atom, and this atmosphere will be held
in its position by various degrees of force, which will draw the
atoms of light nearer to each other as they approach the atom
of matter, and thus give it greater intensity (density). The
atmosphere, it is supposed, will be divided into strata of dif-
ferent intensities, forming concentric spheres ; every atom of
light at equal distances from the centre being held in its po-
sition by equal forces."

"^. The point of saturation, under ordinary circumstances,
will be when the repulsive force of the light is sufficient to
counteract the attraction of the central atom of matter ; when,
with the exception of the attraction of the atoms of matter for

* Abstract of a series of papers, entitled *' Outlines of a theory intended
to connect the operations of nature upon general principles."

-2 Z 2

S56 Mr. P. Cooper's Notice of a Theory of Molecular Action,

each otlier, forming the force of gravitation, the atoms will be
neutral ; the opposing forces of attraction and repulsion being
equal."

Hence as these forces are obedient to the same law of di-
stance, light, whether disengaged in the form of caloric, or
united in a more compressed state to the atmosphere of an
atom of matter, must be imponderable ; the attraction of the
surrounding matter being everywhere counteracted by the re-
pulsive force of the light attached to it.

My theory, it will be observed, differs from M. Mossotti's,
among other particulars, in confining the repulsive force to
the atmospheres of light which surround the atoms of mat-
ter; but as these atmospheres are connected with their re-
spective atoms by a powerful attraction, the repulsive force of
contiguous atmospheres will be equivalent in effect to a re-
pulsion between the atoms themselves.

Every known operation of nature may be inductively traced
from the simple principles assumed in this theory without the
slightest deviation from the laws assigned to matter and light,
its only agents. But by far the most interesting and important
part of these phaenomena are produced by the derangement
of the atmospheres of light which surround the atoms of mat-
ter, arising from their repulsive action upon each other. The
quantity of light attached to each atom is not materially altered
by this derangement ; but, as the neutral state of the atoms is
derived from an exact equilibrium between the attractive and
repulsive forces, to which an uniform state of their atmo-
spheres is essential, the unequal distribution of the light which
forms these atmospheres must give them polarity, by render-
ing the part of the atmosphere where the light is in excess,
positive, in comparison with the part of the atmosphere of the
same atom from which this excess is taken, and which must
be in an equal degree negative. The polarity thus induced,
which requires the contiguity of dissimilar atoms, or atoms
the atmospheres of which differ in density, and consequently
in electrical force, is the foundation of the attraction by which
these atoms are united when in a state of cohesion ; and a
similar polarity, induced by the action of contiguous masses,
or bodies of atoms thus united, which also for this purpose
are required to exhibit to each other surfaces of light of dif-
ferent intensities, is the foundation of all the phaenomena of
electricity. I remain, Gentlemen, yours, &c.

Bawlish, Shepton Mallet, Paul Cooper.

April 10, 1837.

P.S. I am preparing a paper in which these principles will
be applied to the explanation of the peculiar condition of iron
discovered by Dr. Schcenbein; and which, in connexion with

Mr. G. Bird oti the Action of Electricity on Albumen. 357

this subject, will include an explanation of electro-chemical
action generally.

[NOTE. — We may take this opportunity of referring those
who are interested in the philosophy of molecular action, to the
account of the theories of Father boscovich and Mr. Michell,
in Dr. Priestley's Disquisitions on Matter and Spirit, vol. i.
p. 38, &c. ; and in his Correspondence with Dr. Price, pp. 47,
24?3, &c. This account, we think, may be advantageously read
in connexion with the memoir of M.Mossotti. In a Memoir
on the Absorption of Light, the continuation of which will ap-
pear in the next Part of Scientific Memoirs, the Baron
von Wrede says, " We must not be thought too bold when we
suggest that by observations on the absorption or light we
may find a new way opened to us of viewing the constitution
of matter which may perhaps lead to results that could be at-
tained in no other way." — Edit.]

LXX. On the Action of Electricity on Albumen, By
GoLDiNG Bird, Esq..^ F.L,S., F.G.S., Lecturer on Experi-
mental Philosophy at Guy's Hospital,^

To Richard Phillips, Esq., F.R.S., S^c,
Dear Sir,
¥ FEEL exceedingly indebted to you for pointing out to
-* me the observations of M. Lassaigne on the coagulation of
albumen by electric currents, in the Annates de Chimie. From
this paper it appears that M. Lassaigne applied a similar ex-
planation to the coagulating influence exerted by electric cur-
rents on free albumen to that which I ventured to propose
in a late number of your Magazine*. The original paper in
the Annates de Chimie is very brief, and the author's hypothesis
is expressed in the following words :

"(L'albumine) la plus pure qu'on puisse se procurer pro-
vient de I'oeuf : encore celle-ci contient-elle une petite quantite
de chlorure de sodium. II doit necessairement arriver, lors-
qu'on soumet une pareille solution a Taction de la pile, que la
petite quantite de sel qu'elle renferme se decompose de ma-
niere que Pacide se porte vers le pole positif, tandis que sa

base est attiree vers le pole negatif. : done Talbumine

mise en contact avec le pole positif, oii vient se rendre Tacide,
doit se combiner avec celui-ci et se pr^cipiter." {Annates de
Chimie et de Physique, tome xx. p. 98.)

M. Lassaigne mentions the coagulation of albumen at the
positive electrode only, and makes no reference to those cases
in which it takes place at the negative electrode, as in Mr.
Brande's experiments referred to in my last communication.
* See vol. ix. p. 109, and p. 84 of the present volume. — Edit. '

358 M. Becquerel ow an Electro-magnetic Balance,

The only experiment detailed by Lassaigne in direct sup-
port of his hypothesis is by no means satisfactory, involving
as it does the necessity of the solubility of albumen after its
coagulation by alcohol in distilled water; still as the experi-
ment is interesting and worthy of repetition, I shall, in justice
to the talented chemist who performed it, take the liberty of
copying the recital of it.

" ....Le moyen que nous avons, employe pour y parvenir
a ete la coagulation du blanc d'oeuf par I'alcool a 28°, et son
lavage k plusieurs reprises jusqu'a ce que la dissolution
d'argent n'y demon trat plus la presence du chlore.

" L'albumine ainsi traitee a ete mise avec de I'eau distillee ;
une petite quantite s'y est seulement dissoute, car la solution
precipitait par I'acide nitrique Tinfusion de noix de galle, et
etait troublee par la chaleur.

" Nous avons place cette solution dans un tube de verre re-
courbe en siphon, et nous I'avons soumise a un courant gal-
vanique : elle ne s'est nullement troublee; mais apres y avoir
ajoute quelques gouttes d'une solution de chlorure de sodium,
nous avons observe au pole positif qu'elle est devenue laiteuse,
et qu'elle a depose des flocons blancs." {Ann. de Chim,et de
Phys. torn. xx. p. 99.)

From these observations it appears that in the theory of the
action of electric currents on albumen I have been antici-
pated; which is rather gratifying to me than otherwise, as I
trust that the experiments detailed in my last communication
are sufficient, if not to prove, at least to render highly pro-
bable, the correctness of the hypothesis proposed by M,. Las-
saigne in the paper above alluded to.

I remain, dear Sir, yours truly,

22, Wilmington Square, April 4, 1837. GoLDING BlRI).

hlL^l. Description and Use of an Electro-magnetic Balance, and
of a Battery with invariable Currents. By M. Becquerel.*

TIJITHERTO we have possessed only two modes of com-
-■--■- paring the relative intensities of electric currents. One
consisting in making a magnetic needle oscillate for a given
time, at the same distance, from a conducting wire traversed
by currents possessing different degrees of energy, and then
calculating the intensity of each by means of the formula for
the pendulum ; the other requiring the employment of the
galvanometer.

Neither of these methods enables us to refer the intensities
of a current to a common measure that may be obtained with

• From the Comptes Rendus de f Academic Roy ale des Sciences for 1837>
No. 2, &C.J being an abstract of a paper read before the Academy, Jan. 9.

mid on a Battery with invariable Currents. 359

facility, although this is an object which we should keep con-,
stantly in view while studying the action of the electric forces.
I have endeavoured to compare the electro-magnetic effects
of a current by means of weight. The following is a descrip-
tion of the apparatus I employ. I take an assaying balance so
delicate that it will be turned by a fraction of a milligramme^.
At each end of the beam there is suspended from a vertical
pin a scale pan with a magnet having its north pole hanging
downwards. I then fix upon an apparatus properly con-
structed, two glass tubes of such a bore that the two magnetic
bars may be passed into them without touching their concave
surfaces. Around each of these tubes there is wound a cop-
per wire covered with silk, and so long as to form ten thousand
circumvolutions. After having placed the bars in the direction
of the axis of the spirals, 1 cause an electric current to pass
through the wire. Let us, at first, observe a single spiral ;
it is evident that the magnetized bar, as well as the beam with
which it communicates, will rise or fall according to the di-
rection of the current. Let us now, so place the second spiral
that the beam wmU move in the same direction, when the wire
is traversed by the current, and bring the two spirals to com-
municate with each other ; the actions of both upon the bars
will then necessarily be excited. The use of the apparatus
will be best illustrated by a few examples. Having taken two
plates (one of zinc and the other of copper), each presenting
a surface of 4? square centimetres (=1*6 inch nearly), and
being in communication with the two spirals, I immersed them
simultaneously into ten grammes of distilled water: one of the
scales rose, and it was found necessary to place in it a weight
of 2™*5 (= '0385 grain) in order to restore the equilibrium.
The magnetic needle of a short- wired multiplier, which had
been placed in the circuit, made a deviation of 60 degrees.
A drop of sulphuric acid being added to the liquid, it was
found necessary to employ 35™-5 (= '546 grain) in order to
preserve the equilibrium, l^he two currents were therefore
nearly in the ratio of I to 14.

I subsequently endeavoured to ascertain in weight the ratio
of currents issuing from batteries composed of elements more
or less numerous. With a pile of 40 elements charged with
water, containing ^^^ sulphuric acid, ^V sea salt, and some drops
of nitric acid, 615 milligrammes (= 9*471 grains) were re-
quired to preserve the equilibrium. Hence it follows that this
current is to the current obtained by means of a single pair in
the ratio of IV^^ to \.

For the purpose of measuring the thermo-electric currents,

♦ '0154 grain.

360 M. Becquerel on an Electro-magnetic Balance,

spirals similar to those just mentioned, except that they con-
sisted of two sets of circumvolutions, have been employed. I
have employed them for the purpose of determining the tem-
peratures of the several layers of the flame of an alcohol lamp
by means of two platina wires of different diameters joined
at one end. The temperatures were found to be 1310°'98,
913°-24., 74.3°-56.

The instances adduced in this memoir are decisive as to the
facility with which, by means of weight, we may compare the
intensities of currents produced by electricities of different
tensions.

If we wish to measure the continuous action of a force, we
must first endeavour to give it an unvarying intensity. But
the electric current produced by the common piles, and even
by a single pair, is liable to continual variations, which render
it impossible to make its mode of action the subject of calcu-
lation. In order to obviate this inconvenience I have con-
structed a pile which produces a current whose intensity suf-
fers no sensible variation for twenty-four, and in some instances
for forty-eight hours.

Some years since I made public a very simple apparatus
producing a current varying but little during a given time. It
consists of two small glass phials ; one containing concen-
trated nitric acid, and the other a solution of caustic potash,
also concentrated. The two phials communicate with each
other by means of a bent glass tube, filled with very fine clay
moistened with a solution of sea-salt. Into the phial contain-
ing the alkali I plunge a plate of gold, and into the other a
plate of platina. When the two plates are brought into com-
munication with a multiplier, a current of considerable energy
is found to result from the reaction of the acid on the sea-salt
and the potash. The plate of gold takes the negative elec-
tricity to the alkali, and the plate of platina carries the positive
electricity to the acid.

In order to obtain the maximum effect, due attention must
be given, in the construction of this apparatus, to the fol-
lowing considerations. Were it possible to transform into a
current all the electricity that is disengaged in the combina-
tion of a given quantity of acid with a proportionate quantity
of alkali, this current would, in its turn, decompose all the
salt that is formed. Accordingly, if in the reaction of an acid
on an alkali we can direct a sufficient portion of the electri-
cities disengaged, we shall have a current of sufficient inten-
sity to produce decompositions. For the purpose of partially
attaining this condition, we take two tubes of platina, each
being bent at one end, in order that it may be inserted into
a glass tube. One of the platina tubes is filled with clay

eind on a Battery mth invariable Currents. 361

moistened with nitric acid; the other with clay moistened with
a solution of potash, and the intermediate glass tube with clay
moistened with a solution of sea-salt. The lower ends of the
platina tubes are closed with covers of the same metal pierced
with a great number of small holes. This end of the tube,
which is filled with the clay moistened with acid^ is plunged into
nitric acid, and the same end of the other into a solution of
potash. In order to facilitate the transmission of the electricity
from the clay to the sides of the tubes, the clay is mixed with
a certain quantity of finely divided platina, for the purpose of
increasing its conducting power.

When those arrangements are made, platina wires are at-
tached to the extremities of the bent parts of the tubes for the
purpose of tmnsmitting the current through bodies. By com-
bining several apparatus of the same kind we have a pile the
effects of which are constant.

One of these pairs required S^^'S (= '1232 grain) to pre-
vent the scales from turning. A galvanometer with a short
wire being placed in the circuit, exhibited during the same
time a deviation of 79°. In my memoir I have shown that
during a considerable space of time the effects of this pile un-
derwent no sensible variation. It is easy enough to account
for this invariability in its effects. We know that the decom-
posing metallic plates forming a part of a voltaic circuit, and
when plunged into a solution, are polarized in such a manner
as to produce a current in a direction contrary to that of the
pile. The polarization of each of these plates is manifested
in the deposition of a substance, which is transferred to its sur-
face by the current, and the nature of which depends on the
position of this plate with respect to the extremities of the pile.
So long as this substance remains in contact with the plate,
there is a current in a direction contrary to that of the original
current. But if the substance is surrounded by a body having
a close affinity with the substance, it enters into combination
with it, and the plate is immediately unpolarized. Such is
precisely the case with the different elements of the pile which
we describe. The alkali which is transferred to the negative
plate combines immediately with the surrounding acid, and
the alkali deposited on the positive plate is neutralized by the
acid which surrounds it.

I have entered into some detail respecting the electro-che-
mical effects of the polarization of the decomposing plates,
when they transmit constant currents produced by an appa-
ratus consisting of one, two, three, and four pairs. I then set
forth the result of the first experiments, which I made with
the kinds of apparatus already described, in order to establish

Third Series, Vol. 10. No. 62. May 1837. 3 A

362 M. Becqiierel on an Electro-magnetic Balance^

the relations by which affinities are connected with the electric
forces. Since the discoveries made by Mr. Faraday on the
nature and extent of electro- chemical decomposition, we know
that the chemical power of a current is in the direct ratio of
the absolute quantity of electricity which is in motion. It is
by resting on this principle that he succeeded in his endeavours
to determine the equivalents of bodies ; but in his researches
he disregarded the absolute intensity of the force that is in ac-
tion at each instant. This is the defect which I have sought to
supply by means of my apparatus. It has long been remarked
that the elements which are combined with the greatest energy
are also decomposed with the greatest readiness by currents,
and that the elements which are combined in consequence of
feeble affinities are those which offijr the most obstinate resist-
ance to the decomposing action of electricity in motion. It
seems to follow from this circumstance that all compound
bodies are dissolved under the influence of a current propor-
tioned to the force of the affinity by which their elements are
united. If then we could establish a relation between the in-
tensity of this current and affinity, we should be enabled to
measure the latter. In researches of this kind due attention
must be paid to the following observations of Mr. Faraday :
1st, that the electric powers as well as the chemical action of
electricity are definite; 2nd, that a considerable quantity of
electricity in the form of a current decomposes but a small
quantity of elements ; 3rd, that the electric agent is employed
only for the purpose of overcoming the electro-chemical powers;
whence it may be inferred that the quantity which passes is at
least equal to the quantity possessed by the separate mole-
cules ; 4-th, that there is a perfect accordance between the
theory of definite proportions and that of electro-chemical
affinity, whence it follows that the equivalent parts of bodies
may be considered as volumes possessing equal quantities of
electricity, or at least equal electric powers. The atoms of
bodies which are equivalent to each other in their ordinary
chemical action have therefore equal quantities of electricity
combined with them. The following are the experiments
which I made in order to arrive at the solution of the problem
which I proposed to myself.

When a constant current is made to pass into two differ-
ently saturated solutions of a salt with a reducible base, the
quantity of salt decomposed is exactly the same in both. I
took 2K'"in'8 (= 43*25 grs. nearly) of dry nitrate of copper and
dissolved it in 10»'''"'3 (= about 6 fluidrachms) of water: half
the solution was diluted by a quantity of water equal to it in
volume ; the two copper wires plunged into the two negative

and on a Battery with invariable Currents. 363

branches weighed each 0«'"'*3385{= 5*0775 grs.). After forty-
eight hours these wires weighed 0»""'36 ( = 5'4« grs:) : they
had therefore gained in weight 0^*02i5(= -3225 gr.). The
intensity of the current which produced this effect was repre-
sented by 5 milligrs. (= '077 gr.). The intensity of the cur-
rent being diminished by one half, the quantity of copper re-
duced in tbrty-eight hours was found equal to 0*01, that is, to
half the quantity reduced in the preceding experiment.

The same wire and the same solutions were submitted du-
ring forty-eight hours to the action of a current which coun*-
terbalanced 3 milligrs. (= '0462 gr.) : the quantity of copper
obtained was 0'"'012. Now, if the quantities of copper re-
duced in the two experiments be compared, they are found
to be exactly proportional to the intensities of the current.
Several experiments of the same kind were made with solu-
tions of nitrate of silver by varying the density of these so-
lutions and the intensity of the current. The quantities of
metal reduced were exactly proportional to the variations of
the current, the source being constant; the constancy of the
source being an indispensable condition.

These results follow from the observations of Mr. Faraday.
But between his results and those which I have just stated
there is this difference, that he has disregarded the absolute
intensity of the current, whilst I take it into account. We
shall show in another memoir the advantages derived from
this new element introduced into experiments connected with
electro-chemical researches.

We have endeavoured to ascertain by means of the electro-
magnetic balance, the proportions in which the quantities of
reduced metal are found, when solutions of several metals are
subjected to the action of the same current, of a known inten-
sity. Three solutions, one of copper, another of silver, and
a third of zinc, were introduced into the circuit. These solu-
tions were placed in tubes of the form of a U, and each of
them was in contact on the negative side with a plate of pla-
tina, and on the positive side with a plate of the same metal
as that in solution. They were subjected to the action of an
apparatus consisting of two pairs prepared with the cylinders
of platina ; the following are the results obtained.

The intensity of the currents balanced a weight of 5"^'5
(='0847gr.). After twenty-four hours the silver precipi-
tated weighed 0™*305 ; the weight of the copper precipitated
was 0"^'090 ; that of the zinc precipitated was 0"''0925. Now
if we consider the proportion of the three quantities of metal
precipitated, we shall find that they are proportional to the
atomic weights of the silver, the copper, and the zinc, inasmuch

3A2

364 Mr. Talbot*s Experifizent on the Interference of Light,

as 305 (the weight of the first) is to 90 (the weight of the se-
cond) as 108 (the atomic weight of the silver) is to 31*8, instead
of 31*6 (the atomic weight of the copper). In like manner,
305; 92*5: : 108 (the atomic weight of the silver) is to 32*8
(the atomic weight of the zinc,) instead of 32*5, found by Mr.
Faraday. It is evident, then, that the apparatus with a con-
stant current, and consisting only of two pairs, together with
the electro-magnetic balance, enables us to find the atomic
weights of metals, and to determine the quantities of reduced
metal that correspond to a given intensity of current.

LXXII. An Experiment on the Interference of Light,
By H. F. Talbot, Esq,, F.R.S.*

T BELIEVE the following experiment to be a new one, and
■*• it seems to alFord a satisfactory illustration of the theory.

Make a circular hole in a piece of card of the size of the pupil
of the eye. Cover one half of this opening with an extremely
thin film of glass (probably mica would answer the purpose
as well, or better). Then view through this aperture a per-
fect spectrum formed by a prism of moderate dispersive power,
and the spectrum will appear covered throughout its length
with parallel obscure bands, resembling the absorptions pro-
duced by iodine vapour.

The cause of this phaenomenon probably is, that one half
of the light which passes through the glass film his its undu-
lations thereby retarded by a certain quantity, which may be
called A.

Let L be the length of the undulation of any coloured ray,
which I suppose to be a much smaller quantity than A.

Then if we consider the colours in succession, L increases
progressively from the violet to the red. Consequently the

quotient -|- becomes by turns a whole number and a fraction,

and then again a whole number, and so on alternately a

A

great number of times. Whenever -p- is a whole number,

the two halves of the light agree in the phase of their undu-

lation. But when -y- is midway between two whole num-

bers, the two portions of light are opposed in phase, and
therefore the corresponding colour cannot make its appear-
ance in the spectrum at all ; and therefore also a dark band
appears in the place it would have occupied.
• Communicated by the Author.

[ 365 ]

ILXXIII. On the Carboniferous Series of the States of New
York and Pennsylvania, By Thomas Weave k, Esq.^
RR,S., RG,S., M.R.LJ., ^c, ^c*

1 T is only very lately that my attention has been drawn to
^ the observations of Mr. R. C. Taylor on the Carboniferous
Series of the United States of North America, published in the
Lond. and Edin. Phil. Mag., for December 1836, and which
have reference to my notice on the same subject inserted in
the same Journal for August 1836. As the author does not
in all cases appear to have entered into the full scope of my
argument, or to have wholly considered the reasons of my per-
suasion that Professor Eaton had established the true position
of the anthracitous coal formation in the north-eastern part of
Pennsylvania; observing also (p. 410) that " he does not know
which of the calcareous rocks is meant by Prof. Eaton as the
limestone which supports the strata containing the Pennsyl-
vanian coal," perhaps a few additional remarks may serve to
throw some further light upon the subject.

In the notice referred to, I have stated that in the northern
part of the State of New York, the progression from north to
south, in the ascending order, and extending into Pennsylva-
nia, is as follows, — all the beds being in conformable position
with a general dip to the southward : 1 . old red sandstone ;
2. carboniferous limestone ; 3. coal measures, distinguished by
the prevalence of red shales and red sandstones, with beds of
sandstone conglomerate and of limestone, the whole forming
an alternating series, in which coal appears hitherto to have
been rarely met with ; 4. productive coal measures, containing
abundant deposits of anthracitouscoal in the coal-fields of Car-
bondale and Lackawanna and Wyoming on the Susquehanna,
and of bituminous coal in the coal-fields of Bradford, Tioga,
Lycoming, and Clearfield.

The main body of the carboniferous limestone (No. 2.), rest-
ing on the old red sandstone (No. 1.), extends from the north-
ern extremity of Lake Erie, in an easterly direction, through
the State of New York, to the Heklerberg mountain, situated
about 20 miles to the S. W. of Albany. Here its course is in-
flected to the S. and S.W., and Prof. Eaton states that he has
followed this limestone upon that range 120 miles from the
Helderberg mountain, extending into Pennsylvania on the
right bank of the Delaware river, and being flanked through-
out in this direction by transition rocks on the eastf. The

• Communicated by the Author.

t Geological Text-Bcok, 2nd edit., pp. 66, 67.

366 Mr. Weaver on the Carboniferous Series

carboniferous limestone thus appears to support not only
tlie bituminous coal measure series of the Alleghany and
Catskill mountains on the N. and the E., but also to inclose
and support on the E. the anthracitous deposits of Carbondale,
Lackawanna, and Wyoming ; in fact, serving as a base to the
alternating series No. 3, which supports the more productive
coal-bearing measures No. 4<*. The further continuity of the
anthracitous range from Wyoming to the southward, through
the regions bordering on the Lehigh and Schuylkill rivers,
and their probable juxtaposition in that direction with trans-
ition rocks on the east, I have already adverted to in my no-
tice of August, 1 836.

In the State of New York, the southern border of the main
body of the carboniferous limestone intersects upon its range
the Lakes Seneca and Cayuga, and near the heads of those
lakes, on the south, the coal measures No. 3 contain thin layers
of bituminous coalf. The same occurrence has been remarked
inOtsego county in the shale lying above the limestone J. In
the same manner narrow seams of bituminous coal have been
found in the Catskill range bordering on the river Schoharrie,
and again in the southern part of the same range in Ulster
county, varying from 8 to 22 inches thick, the beds being in
some places horizontal, but in general slightly inclined to the
west§. To what extent other seams of coal may occur in the
higher accumulation of these coal measures No. 3, subjacent to
the great anthracitous and bituminous deposits of Pennsylv^
nia in series No. 4, remains yet to be proved.

If to these circumstances of relative position we add the
further consideration that fossil plants are found both in the
anthracitous and bituminous coal-fields of Pennsylvania, which
are identical with those occurring in the bituminous coal-fields
of Ohio and in the great coal-fields of Europe ||; that both
the anthracitous and bituminous coal regions of Pennsylvania
are alike productive of large quantities of clay ironstone ; and
moreover that, so far as it has been shown, the alternating se-
ries No. 3, and the subjacent carboniferous limestone No. 2,
exhibit such other organic exuviae as are common in the car-
boniferous epoch; combining these several data, I do not see
how we can avoid coming to the conclusion that the whole se-
ries, from No. 1 to No. 4? inclusive, belong to the great car-
boniferous order, and that no part of that series belongs to the
transition system.

* Geological Text-Book, pp. 90, 121, 124. f lb., pp. 79, 110.

t lb., p. 121.

§ J. Pierce in American Journal of Science, vol. vi. pp. 94 to 96.
jl Geological Text-book, pp. 91, 125 j and American Journal of Science,
vol. xxui. pp. 399, 400.

of the States of New York and Pennsylvania. 367

This leads me again to the consideration of the alternating
series in Pennsylvania, composed largely of red sandstones
and red shales, with beds of sandstone conglomerate and of
limestone, and some bituminous coal, mostly arranged in
double anticlinal and synclinal order, as exposed to observa-
tion between the bituminous coal ranges of the Alleghany
mountains on the west, and the anthracitous coal region of
Schuylkill, &c. on the east. Had not Mr. R. C. Taylor de-
nominated this alternating series transition, and the red sand-
stone immediately underlying the Alleghany bituminous range
old red sandstone, judging merely by the evidence produced,
and reasoning from analogy, I should have been induced to
consider them as the prototypes or representatives of the class
of beds which appear in the northern face of the Alleghany
mountains, and which I have designated as No. 3 ; both in fact
appearing to form the immediate support of the more produc-
tive coal-bearing measures No. 4. No evidence is given by
the accompanying fossils to prove that this alternating series
belongs to the transition period. On the other hand, it is ad-
mitted by the author (p. 409.) that this alternating series com-
prises four or five troughs or basins containing coal, which on
the eastern side of the State of Pennsylvania is anthracitous,
and on approaching the S.W. contains upwards of 16 per cent,
of bitumen and volatile matter ; while some of the anthracitous
beds pass into bituminous coals in certain places (p. 408). This
fact affords an argument on the other side, as no well authen-
ticated instance exists, so far as my knowledge extends, of a
bed of bituminous coal having ever yet been found within the
limits of the transition system.

This is not a question of mere theoretical speculation, but
one of high practical importance, as connected with geological
investigation and the ceconomical purposes of life; and from
the zealous researches now understood to be in progress, both
in the State of New York and in Pennsylvania, we may rea-
sonably expect that a fuller light will soon be shed upon the
subject; in effecting which the successful labours of Mr. R. C.
Taylor will no doubt appear conspicuous.

To what extent transition rocks may occur in Pennsylvania
within the area circumscribed by the anthracitous range on
the east, the bituminous range on the west, and by both con-
jointly on the north, remains yet to be proved. Should such
appear within that space, it may require some caution not to
confound simple contact with a portion of the carboniferous
series, with an arrangement coordinate with the latter.

A clear exposition of all the relations of the transition system

368 Mr. Brooke on the Identity of Biotine and Anorthite,

vithin the United States is a great desideratum, toward the
accomplishment of which the attention of American geologists
cannot be too sedulously directed.
April, 1837.

LXXIV. Ow the Identity of two Minerals from Vesuvius
named Biotine and Anorthiiey and on a new Variety of
Hemitrope Crystal of Quartz, By H, J. Brooke, Esq.^

[With Figures: Plate III,] .^.;v-<.i:(/ /^ ^ f^
1 N a paper in the last Number of this Journal, p. 278, on the
-■■ regular crystalline composition of two different minerals,
allusion is made to the combination of Felspar and Cleaveland-
ite in crystals, which, however, by an error of the press, are
said to be from Bavaria instead of Baveno,

The exact relations of the crystals of these two minerals
and of Anorthite have not, that I am aware of, been exactly
pointed out so as to explain the combination referred to, and
I am therefore induced to request the editors to allow a space
for the figures alluded to below.

Fig. 1. (Plate III.) is an oblique rhombic prism, now
adopted as the primary form of Felspar. The small figure
marked P M T, the faces of which are parallel to the cleavage
planes, was regarded by Haiiy as the primary, and I'rom the
relation which subsists between these two figures, the se-
condary forms of felspar might be derived from either.

Assuming for the present purpose the small figure, en-
larged and represented by fig. 2, as the primary, the follow-
ing analogy and differences of angles will be found to subsist
between Felspar, Anorthite and Cleavelandite.

P on T. P on M. T on M.

Anorthite 86° 110° 40' 117° 30'

Felspar 90 112 ]20 35

Cleavelandite ... 93 30' 115 119 30

The crystals of Cleavelandite are formed over the planes
T and M of Felspar, with their axes parallel to the intervening
edge.

Fig. 3 represents a regular crystal of Anorthite, and figg.
4 and 5 two crystals of the variety named Biotine. The cry-
stal of Anorthite is lengthened proportionally in the direction
of its axis, and fig. 4 of Biotine very disproportionally in the
direction of the oblique diagonal. It appears from M. Monti-
celli's figures that he has considered the planes T, 7i, P, e, as
• Communicated by the Author.

and on a nem Crystal of Quartz, 369

those of a prism distinct from Anorthite, and has assumed the
Others to be terminal planes. But the correspondence of the
planes marked by similar letters in the figures may be ascer-
tained by means of the reflective goniometer, so as to remove
all doubt of the identity of the two minerals. Many of the cry-
stals named Biotine are flat, and have apparently square ter-
minal planes as shown in flg. 4, which is a remarkably de-
ceptive crystal, and without reference to the goniometer might
easily be supposed not to belong to Anorthite.

A crystal of quartz in the writer's cabinet, resembling fig. 8,
and said to have come from Dauphine, presents a hemi-
trope form differing from any hitherto described. In carbo- ^ ^
nate of lime the axis of revolution of twi^n crystals is parallel "^
or perpendicular to the crystallographic axis, or perpendicular ^f^9
to a primary plane, or to a tangent plane on a primary edge ;
and in all other cases it has been found parallel or perpendi-
cular to an axis, or perpendicular to a primary edge or plane,
or to a single plane produced by some simple law of decre-
ment. Indeed so universal have these relative positions of
the axes of revolution been in all the instances hitherto de-
scribed, that they have been regarded by Haiiy and others as
fundamental laws of this kind of structure. Haiiy's expres-
sion (Cryst., vol. ii. p. 273) is, " Le plan qui est cense avoir
partage le crystal original en deux moities est toujours paral-
lele, soit a une des faces du noyau, soit a une face produite en
virtue d'une loi simple de decroissement sur les bords ou sur
les angles du meme noyau."

Tlie axis of revolution of the crystal fig. 8 is perpendicular
to one of a pair of planes replacing an edge of the primary
rhomboid, resulting from a complicated, intermediary law, ex-
pressed, according to the notation of Haiiy, by (B 1 D^ Dj)>
and which would produce tangent planes on the edges of the
pyramid of the common crystals of quartz. Fig. 6. shows the
position of these planes «, a\ a'\ on the primary rhomboid ;
and fig. 7. shows their relation to the hexagonal pyramid.
These planes a do not occur on the hemitrope crystal, fig. 8,
but as the axis of revolution is perpendicular to the edge dcy
it must consequently be perpendicular to a tangent plane re-
placing that edge.

Assuming 94° 15' as the angle of the rhomboid of quartz,
the inclination of the e(\ge dc of the pyramid on the axis will
be 42° 16', and consequently the angle d e d' will be 84° 32'.

H. J. B.

Third Series. Vol. 10. No. 62. il% 1837. 3B

[ 370 ]

LXXV. On the Rev. J. G. MacVicar's Experiment on Vision.
By J. T. Graves, Esq., A.M.*

nPHE ordinary laws of reflection and perspective are suffi-
-^ cient to account for the radiated appearance described by
the Rev. Mr. Mac Vicar {ante, p. 234,) without the hypothesis
of any hitherto unknown symmetrizing power in the eye.

No radiation is observed when the particles are spread at
whatever distance over a non-reflecting surface, or are placed
in immediate contact with a reflecting one. Now if a reflecting
surface in the required position of contiguous parallelism to
the plane of the dust contributes to the success of the experi-
ment, it is surely a priori likely that it does so rather by the
addition it makes to the objects of vision than by any induced
alteration in the mechanism of the eye, affecting the mode in
which the former objects, if seen alone, would be viewed. Ac-
cordingly we are led to consider the actual nature of the pic-
ture before us when the phaenomenon is observed.

When we survey with one eye dust spread over a common
looking-glass, we see not only the particles themselves but
their images reflected by the mercury (wherever those images
are not intercepted by the position of other particles on the
glass), and both classes of objects, from their general similarity
of appearance, are referred to the same plane. Upon further
examination we shall perceive that every reflected image when
referred to the external surface of the looking-glass, appears
in a direct line between its prototype and the point of that
external surface nearest the centre of the eye. In making this
observation, we may use with advantage small shots or seeds
instead of flour or other finely-powdered substances, and we
may put out of consideration the fainter and scarcely percep-
tible images formed by reflection at the external surface, as
they do not materially alter the general picture. Now the
appearances above described might have been predicted as
the necessary results of known principles.

Within the ordinary limits of the sphere of sight, it is an
observed approximate law of vision, whether direct or in-
direct, that when a pencil of rays diverging from any point
enters the pupil, an image is seen in the direction of the line
drawn from that focal point through the centre of the eye.
Again, it is an observed law of light that the angles of inci-
dence and reflection are equal and in the same plane. From
the latter law it follows by simple geometrical reasoning, that
all the rays proceeding from any point and reflected by a

* Communicated by the Author.

On the Rev. J. G. Mac Vicar's Experiment on Vision, 371

plane mirror diverge after reflection from an opposite corre-
sponding point equidistant from the mirror; and it also fol-
lows that the line joining the conjugate points from which
direct and reflected pencils diverge is perpendicular to the plane
of the mirror. Hence if we have a perspective plane pa-
rallel to the plane of the mirror, and carrying all the ob-
jects to be reflected, the line of direction in which, by the pre-
ceding law of vision, any reflected image is seen will cut the
line which joins the object and the point of the perspective
plane nearest the centre of the eye, in the ratio which twice
the distance of the perspective plane from the mirror bears to
the distance of the same plane from the centre of the eye.
While the head remains unmoved, the rolling motion of the
eye does not affect the position of its centre, and consequently
the apparent positions of the reflected images as well as those
of their direct objects remain unaltered.

The relative position of the particles and their images to the
point of the perspective plane nearest the centre of the eye
will account for the radiated appearance. The interval be-
tween each particle and each image produces a short line
pointing in a given direction. The multitude of such pointers
and the multitude of instances in which separate pointers com-
bine to form a prolonged continuous line radiating to a given
centre, actually produce in the spectrum a predominant sym-
metry, which the mind, without any previous peculiar adjust-
ment of the eye, can scarcely fail to notice.

We may form a similar radiating group of objects of vision,
which shall not have the disadvantage of being altered as to
half its components by every motion of the centre of the eye,
if we first dot a sheet of paper indiscriminately, and then
mark a second system of dots so related to the former that the
interval between each pair of conjugate dots may tend in di-
rection to an assumed centre and be proportional in length to
its mean distance from that centre. Here it is evident on in-
spection that no extraordinary symmetrizing power is required
to perceive the radiation. We may observe, however, that if
we mark the second system only to a certain distance, around
the assumed centre, a principle of continuity will incline us
to trace the resulting radiation beyond that distance, by draw-
ing our chief attention to the exterior points in the original
system in so far as they continue the discovered symmetry.
Again, if we mark the first system of dots in blue, and the
second in red, the radiation resulting from the combined po*
sition of the systems will fix our attention on the parts of each
system in so fer as they contribute to the joint effect, so that
when the two systems are simultaneously viewed as separate

3B2

372 On the. Rev. J. G. Mac Vicar's Ejcpetiment oti Vision,

wholes, they will each appear to radiate. If this were re-
peated often enough, we might perhaps afterwards be able to
trace a radiation in either system unbacked by the guidance
of the other, for the eye is predisposed to recur to that atti-
tude in which while previously looking at an object symmetry
has been perceived.

The eye has parts severally capable within certain limits
of distinct adjustments voluntary or instinctive. From natural
conformation, acquired habit, or the present immediate opera-
tion of metaphysical causes, the eye seeing simultaneously the
whole of a given field, may probably possess a superior facility
of severally adjusting its mechanism by parts corresponding
to parts of the field in some manners rather than in others,
and may also be predominantly inclined to alter its sphere of
vision in particular directions. Hence in a group of objects
in which different laws of arrangement are discoverable, one
attitude of the eye may be the best adapted for the discovery
of one law and another for that of a different one. For example,
let a sheet of paper be dotted in such a manner that each sur-
rounded dot may be the centre of a regular hexagon, of which
the surrounding dots mark out the apices ; then the rows, in
which the mind will lioithout effort arrange the dots, will vary
with the direction of the eye, and, with effort, the grouping
may be altered without altering the field of vision. A similar
observation may be made in looking at large piles of cannon
balls. Not the imagination merely but the plastic eye of
Phidias is at work while he is delineating the Venus in the
yet uncarved marble before him. That visual prejudice which
consists in a tendency to adjust the respective parts of the eye
in particular modes, not naturally suggested by the general
impression resulting from the objects presented to those parts,
is a defect exemplified in persons who see ghosts in the win-
dow-curtains and faces in the burning embers.

Though the interesting experiment which Mr. Mac Vicar
has introduced to the public in the pages of this Magazine,
does not seem adapted to illustrate the changes that take place
in the eye, corresponding to the changes that take place in the
grouping and symmetry seen in the subjective spectrum of
a given object, it may be of use for a purpose of scarcely in-
ferior curiousness and importance; for if we compare what
we see in surveying the powdered looking-glass with both eyes,
with the phaenomena which we should expect to result from
the separate and different spectra due to each eye singly, we
may perhaps be enabled to throw light on some obscure pro-
cesses in the physiological mechanism of binocular vision.
This, however, is an inquiry deserving consideration by itself*

Prof. Johnston on Baryto-calcite 373

For the present let it suffice to have indicated the general
causes of the radiated appearance seen in Mr. MacVicar's ex-
periment. J. T. Graves.

[Communications on the same subject have been received
from Mr. H. S. Peacock of London, Mr. William George
Horner of Bath, Mr. Robert Wilson of Glasgow, Mr. J. l5e
C. Sowerby of Camden Town, Mr. G. Dodd of London, and
Mr. G, H. Hoffman, Surgeon, of Margate. They all agree
in referring the phaenomenon in question to the principles of
reflection and perspective explained in the preceding paper,
and the three latter gentlemen respectively mention that they
had observed the radiated appearance for considerable periods
before the publication of Mr. Mac Vicar's letter. — Edit.]

LXXVL On the Composition of the Right Rhombic Baryto-
Calcite^ the Bicalcareo- Carbonate of Baryta o/'Dr.l'homson.
By James F. W. Johnston, A,M.^ F.R.S.E.^^ Professor of
Chemistry and Mineralogy in the University of Durham,*

TN the sixth volume of this Journal, p. 1, 1 described a
-*- mineral occurring in the lead-mine of Fallowfield near
Hexham, Northumberland, which I had found on analysis to
be a true baryto-calcite, though having a form wholly irrecon-
cileable with the doubly oblique prism of the original baryto-
calcite of Brooke.

Since the publication of this description, Dr. Thomson of
Glasgow inserted in the Records of Science, vol. i. p. 369,
and more recently in his System of Mineralogy, vol. i. p. 141,
an account of a mineral from Bromley Hill mine near Alston,
having the same specific gravity and the same crystalline form
as my new baryto-calcite, but having a different composition.

My attention was first drawn to this circumstance b}' my
friend Mr. Brooke, who at once recognised my second form
of baryto-calcite in the mineral of Dr. Thomson, and aware
of the importance of a knowledge of the true composition of
this mineral to the doctrine of isomorphism, requested to know
whether I had actually analysed my specimens from Fallowfield.

My analysis gave the formula Ca C-f-Ba C, that of Dr. Thom-
son 2 Ca C + Ba C, and hence the name Bicalcareo-carbonate
of Baryta which he has assigned to the mineral.

Unwilling to leave the matter in doubt I repeated my ana-
lysis of the Fallowfield mineral.

* Communicated by the Author.

374? Prof. Johnston o?t the Composition of

1st. 72*13 grs. dissolved in dilute muriatic acid and the
gas made to pass over chloride of calcium, lost 21*18 grs.
= 29*363 per cent, of carbonic acid.

2ndly. 50*57 grs. dissolved in muriatic acid, precipitated
by fluo-silicic acid and heated to redness, gave of fluoride of
barium 29*18 grs. = 32*996 carbonate of baryta, or 65*24<8
per cent.

The filtered solution was poured into a large quantity of
water saturated with sulphate of strontia, and precipitated by
sulphuric acid. The precipitate weighed 1*81 gr., and be-
sides strontia contained also the small quantity of baryta held
in solution by the fluo-silicic acid. If we neglect this small
quantity of baryta, we have 1*456 or 2*87— per cent, of car-
bonate of strontia.

A specimen from Bromley Hill, Dr. Thomson's locality,
when dissolved in muriatic acid, left 0*16 per cent, of insoluble
matter, and gave 29*71 per cent, of carbonic acid.

36*58 grs. precipitated by fluo-silicic acid gave 20*14 grs.
of fluoride = 22*774 or 62*156 per cent, of carbonate of
baryta.

The sulphate of strontia obtained as before, and containing
a little baryta, weighed 3*02 = 8*256 percent. = 6*641— car-
bonate of strontia.

33*05 grs. dissolved in muriatic acid largely diluted and
precipitated by sulphuric acid, gave of sulphates* 26*84 grs.

The supernatant solution precipitated by oxalate of am-
monia gave 10*01 of carbonate of lime or 30*29 per cent

The doubly obhque baryto-calcite of Mr. Brooke treated
in the same manner gave me of carbonic acid 30*05, of car-
bonate of baryta 65*97, and of carbonate of strontia 2*3 1 7 —
per cent.

The following table exhibits these results in connection with

• I have said sulphates, as it is hardly possible to free the precipitate
thus obtained from a trace of lime. It also contained sulphate of strontia.
41*27 grs. of the Fallowfield mineral gave me a precipitate weighing 58'88

grs. (it should be in pure Ba C+Ca C, 56*36). Boiled in nitric acid it lost
3*31 grs. ; again boiled 45*94 grs. lost 1*82, and a third time 40*065 grs.
lost 0*51. Evaporated to dryness and the dry mass converted into chlo-
rides, I obtained a deliquescent chloride of calcium, tabular crystals of
chloride of barium, and prismatic crystals giving the characteristic purple
flame of chloride of strontium. Though the last portions of lime and
strontia therefore may be dissolved out by repeated boiling in dilute nitric
acid, it would appear that the sulphate of baryta itself is not wholly inso-
luble in this menstruum.

the Right Rhombic Baryto-calcite,

S75

the analysis of Dr. Thomson and the specific gravities of the
several specimens analysed.

Theory.

Fallow-
field.

Bromley Hill.
Johnston. Thomson.

Doubly
oblique from
Alston Moor.

Carbonic Acid

Carbonate of Baryta . .
Carbonate of Lime....
Carbonate of Strontia

29-625
66-102
33-898

29-363

65-248+

2-87-

29-71
62-156+
30-29
6-641-

49-31-
50-69

3005
65-97+

2-317-

Specific gravity at )
60° Fahrenheit S

3-694 \
♦3-706/

3-70

3-718

3-646

Dr. Thomson informs me that his mode of analysis was to
convert the mixed earths into nitrates and digest in absolute
alcohol, a method sufficiently simple yet requiring consider-
able precautions to secure accuracy. It is barely possible
that a small portion of the matrix of carbonate of lime on
which the mineral rests may have escaped his notice and been
mixed with the quantity analysed.

In my former account of this mineral I did not advert to
the presence of carbonate of strontia, as I had not attempted to
separate it quantitively. It is interesting, however, to find as
the above results show, that this substance is capable of re-
placing, indifferently, either one or both of the isomorphous
carbonates of lime and baryta, and in variable quantity. In
the oblique rhombic (Brooke's), column 6th, it replaces 2 per
cent, of the carbonate of lime, while in the right rhombic it re-
places a portion of both, and in the specimen analysed from
Bromley Hill about 3 per cent, of each.

Sul-phatO' carbonate of Baryta. — Among the interesting new
barytic minerals described by Dr. Thomson (Mineralogy,
vol. i. p.l06,) from the same locality, — Bromley Hill minenear
Alston, — is one affecting the form of large six-sided prisms ter-
minated by hexagonal pyramids, consisting of 34*3 or one atom
of sulphate, and 64*82 or 2*2 atoms of carbonate of baryta.
This mineral is said by the dealers to be found abundantly at
the above mine; I have not however been able to obtain a
specimen of the true sulphato-carbonate. In the cabinet of
the Natural History Society of Newcastle, are two specimens
ticketed sulphato-carbonate, both from Bromley Hill. One
of these is in large obscure prisms an inch in diameter com-
posed of a congeries of small ones resting on a matrix of sul-
phate of baryta. This specimen agrees with the description

• After heating to redness, during which it decrepitates slightly and be-
comes opake, it had a specific gravity = 3-639.

376 Royal Society.

of the mineral by Dr. Thomson, and is said to have been pre-
sented by him. I find these crystals to be carbonate of baryta
nearly pure, dissolving readily in muriatic acid and leaving
an insoluble residue of 0*3 per cent.

The other specimen is in broad flat pyramids, composed
also of a congeries of minute crystals; is grayish, has a pearly
lustre, and rests on right rhombic baryto-calcite. These cry-
stals were obtained from a mineral-dealer, and are also car-
bonate of baryta with a little lime. Lime indeed in this di-
strict seems to be very generally associated with the barytic
minerals. Carbonate of baryta is exceedingly abundant at
Faliowfield lead-mine, is generally of a pure white, and was,
till lately, collected and exported in considerable quantity to
the potteries in Staffordshire. The trade, however, has de-
clined from its being found to contain too much lime.

It would appear therefore that the name bicalcareo-carbo-
nate of baryta must at present be laid aside, being imposed
by Dr. Thomson under a misapprehension in regard to the
true constitution of the mineral ; and that the sulphato-carbo-
nate, if it exists is a much rarer mineral than is generally
supposed, and so much resembles the large* crystals of com-
mon carbonate of baryta as to deceive the discoverer him-
self.

Durham, April 14, 1837.

LXXVII. Proceedings of Learned Societies.

ROYAL SOCIETY.

[Continued from p. 222.]

February 2,_" /RESERVATIONS on the Electro-chemical In-

1837. ^^ fluence of long-continued Electric Currents of

Low Tension." By Golding Bird, Esq., F.L.S., F.G.S., Lecturer
on Experimental Philosophy at Guy's Hospital. Communicated by
Thomas Bell, Esq., F.R.S.

The author, after observing that the brilliant discoveries in electro-
chemistry obtained by Sir Humphry Davy were effected by the employ-
ment of voltaic currents of high intensity,'elicited by means of large bat-
teries, adverts to the labours of M.Becquerel, to whom we are indebted
for the knowledge of the chemical agency of feeble currents in re-
ducing several refractory oxides to the metallic statef : and also to
those of Dr. E. Davy, Bucholz, and Professor Faraday in effecting
decompositions of oilier substances by similar means. In prosecuting
this branch of inquiry, the author employed an apparatus analogous
to that of Professor Daniell, for obtaining an equal and continuous

• Carbonate of baryta is sometimes met with at Faliowfield in large
translucent crystals three or four inches long and two or three in diameter.

t Details of M. BecquereFs researches will be found in Scientific
Memoirs, No. III.— Edit.

Royal Society. 377

current of low intensity from a single pair of plates : the metallic so-
lution, in which a copper-plate was immersed, being contained in a
glass tube, closed at the bottom by a diaphragm of plaster of Paris,
and itself plunged in a weak solution of brine contained in a larger
vessel, in which a plate of zinc was immersed j and a communication
being established between the two metallic plates by connecting wires.
By the feeble, but continuous current thus elicited, sulphate of copper
is found to be slowly decomposed, affording beautiful crystals of me-
tallic copper. Iron, tin, zinc, bismuth, antimony, lead, and silver
may, in like manner, be reduced, by a similar and slightly modified
process ; in general appearing with metallic lustre, and in a crystal-
line form, and presenting a remarkable contrast in their appearance
to the irregular, soft, and sj)ongy masses obtained from the same so-
lutions by means of large batteries. The crystals of copper rival in
hardness and malleability the finest specimens ofj native copper, which
they much resemble in appearance. The crystallization of bismuth,
lead, and silver, by this process, is very beautiful ; that of bismuth
being lamellar, of a lustre approaching to that of iron, but with the
reddish tint peculiar to the former metal. Silver may thus be pro-
cured of the whiteness of snow, and usually in the form of needles.
Some metals, such as nickel, which, when acted on by currents from
large batteries, are deposited from their solutions as oxides only, are
obtained, by means of the apparatus used by the author, in a brilliant
metallic form. He further found that he could in this way reduce even
the more refractory metallic oxides, such as silica, which resist the
action of powerful batteries, and which M. Becquerel could only ob-
tain in alloy with iron. By a slight modification of the apparatus he
was enabled to form amalgams both of potassium and of sodium with
mercury, by the decomposition of solutions of chlorides of those bases ;
and in like manner ammonium was easily reduced, when in contact
with mercury, by the influence of a feeble volt[\ic current. In this last
experiment it was found that an interruption to the continuance of the
current, even for a few seconds, is sufficient to destroy the whole of
the product which had been the result of the previous long-continued
action j the spongy ammoniacal amalgam being instantly decomposed,
and the ammonia formed being divssolved in the surrounding fluid.

February 9. — A paper was read, in part, entitled, *' On the Ele-
mentary Structure of Muscular Fibre of Animal and Organic Life."
By Frederick Skey, Esq., Assistant Surgeon to St. Bartholomew's
Hospital. Communicated by John Bostock, M.D., F.R.S.

February 16. — The reading of Mr. Skey's paper was resumed and
concluded.

The author concludes, from his microscopic examinations of the
structure of muscular fibres, that those subservient to the functions of
animal life have, in man, an average diameter of one 400dth of an inch,
and are surrounded by transverse circular striae varying in thickness,
and in the number contained in a given space. He describes these
striae as constituted by actual elevations on the surface of the fibre,
with intermediate depressions, considerably narrower than the dia-

Third Series, Vol. 10. No. 62. May 183'7. 3 C

378 Royal Society.

meter of a globule of the blood. Each of these muscular fibres, of
which the diameter is one 400dth of an inch, is divisible into bands or
fibrillae, each of which is again subdivisible into about one hundred
tubular filaments, arranged parallel to one another, in a longitudinal
direction, around the axis of the tubular fibre which they compose, and
which contains in its centre a soluble gluten. The partial separation
of the fibrillae gives rise to the appearance of broken or interrupted
circular striae, which are occasionally seen. The diameter of each fila-
ment is one 16,000dth of an inch, or about a third part of that of a
globule of the blood. On the other hand, the muscles of organic life
are composed, not of fibres similar to those above described, but of
filaments only ; these filaments being interwoven with each other in
irregularly disposed lines of various thickness j having for the most
part a longitudinal direction, but forming a kind of untraceable net-
work. They are readily distinguishable from tendinous fibres, by the
filaments of the latter being uniform in their size, and punsuing indi-
vidually one unvarying course, in lines parallel to each other. The
fibres of the heart appear to possess a somewhat compound character
of texture. The muscles of the pharynx exhibit the character of ani-
mal life ; while those of the oesophagus, the stomach, the intestines,
and the arterial system, possess that of inorganic life. The determi-
nation of the exact nature of the muscular fibres of the iris presented
considerable difficulties, which the author has not yet been able satis-
factorily to overcome.

A paper was also in part read, entitled, " On the Function of the
Medulla Oblongata and Medulla Spinalis, and on the Excito-motory
System of Nerves." By Marshall Hall, M.D., F.R.S. L. and E., &c.

February 23. — The reading of Dr. Marshall Hall's paper was re-
sumed, but not concluded.

March 2. — The reading of Dr. Marshall Hall's paper was resumed
and concluded.

The author begins by observing that a former memoir of his, en-
titled, "On the Reflex Function of the Medulla Oblongata and Me-
dulla Spinalis," published in the Philosophical Transactions for 1833,
has been translated into German, and favourably spoken of by Pro-
fessor Miiller, of Berlin*. He states that his object in the present paper
is to unfold what he calls a great principle in physiology j namely, that
of the special function, and the physiological and pathological action
and reactions of the true spinal marrow, and of the excito-motory
nerves. The two experiments which he regards as aftbrding the type
of those physiological phaenomena and pathological conditions, which
are the direct effects of causes acting in the spinal marrow, or in the
course of the motor nerves, are the following : — 1 . If a muscular nerve
be stimulated, either mechanically by the forceps, or by means of gal-
vanism passed transversely across its fibres, the muscle or muscles to
which it is distributed are excited to contract. — 2. The same result
is obtained when the spinal marrow itself is subjected to the agency

• See our present volume, p. 51 et seq. — Edit.

Royal Sociely. 379

of a mechanical or galvanic stimulus. The following experiment, on
the other hand, presents the type of all the actions of the reflex func-
tion of the spinal marrow, and of the excito-motory system of nerves,
and of an exclusive series of physiological and pathological phseno-
mena : — If in a turtle, from which the head and sternum have been
removed, we lay bare the sixth or seventh intercostal nerve, and sti-
mulate it either by means of the forceps or galvanism, both the ante-
rior and posterior fins, with the tail, are immediately moved with
energy. Hence the author infers the existence : 1st, of a true spinal
marrow, physiologically distinct from the chord of intra-spinal nerves j
2nd]y, of a system of excito-motory nerves, physiologically distinct
from the sentient and voluntary nerves j and, 3rdly, of currents of
nervous influence, incident, upwards, downwards, and reflex with re-
gard to the spinal marrow.

A review is then taken of the labours of preceding physiologists
relative to the functions of the nervous system : in which the author
criticises the reasonings of Whytt, Legallois, Mr. Mayo, Dr. Alison,
and Professor Miiller ; and illustrates his own peculiar views by several
experiments and pathological observations, which appear to him to
show that muscular movements may occur, under circumstances imply-
ing the cessation of sensation, volition, and every other function of the
brain j and that these phaenomena are explicable only on the hypothesis
that impressions made on a certain set of nerves, which he terms excito-
motory, are conveyed to a particular portion of the spinal marrow
belonging to that system, and are thence reflected, by means of cer-
tain motor nerves, upon certain sets of muscles, inducing certain ac-
tions. The same actions may also be the result of impressions made
directly either on the spinal marrow or on the motor nerves. He
accordingly considers that the whole nervous system may be divided
into, — 1st, the cerebral, or the sentient and voluntary; 2ndly, the
true spinali or the excitor and motor j and, 3rdly, the ganglionicf or
the nutrient, the secretory, &c. The excito-motory system presides
over ingestion and exclusion, retention and egestion, and over the
orifices and sphincters of the animal frame : it is therefore the ner-
vous system of respiration, deglutition, &c., and the source of tone
in the whole muscular system. The true spinal system is the seat or
nervous agent of the appetites and passions, but is also susceptible
of modification by volition. This theory he proceeds to apply to the
explanation of several phaenomena relating to the motions of the eye-
lids, pharynx, cardia, larynx, muscles of inspiration, sphincter ani,
expulsors of the faeces and semen, to the tone of the muscular system
generally, and to actions resulting from the passions. Lastly, he
considers its application to various diseased states of the same func-
tions, as manifested in cynic spasm, vomiting, asthma, tenesmus,
strangury, crowing inspiration, convulsions, epilepsy, tetanus, hydro-
phobia, and paralysis.

Reference is made, in the course of the paper, to several drawings
and diagrams, which, however, have not yet been supplied.

March 9, 1837.— A paper was read, entitled, " Researches on the

3 C2

380 Uoyal Society,

Tides. Seventh Series. On the Diurnal Inequality of the Height of
the Tide, especially at Plymouth and at Sincapore : and on the Mean
Level of the Sea." By the Rev. W. Whewell, A.M., F.R.S., Fellow
of Trinity College, Cambridge.

The diurnal inequality which the author investigates in the present
paper, is that by which the height of the morning tide differs from that
of the evening of the same day j a difference which is often very con-
siderable, and of great importance in practical navigation, naval offi-
cers having frequently found that the preservation or destruction of
a ship depended on a correct knowledge of the amount of this varia-
tion. In the first section of the paper he treats of the diurnal ine-
quality in the height of the tides at Plymouth, at which port good tide
observations are regularly made at the Dock Yard 3 and these obser-
vations clearly indicate the existence of this inequality. As all the
other inequalities of the tides have been found to follow the laws of
the equilibrium theory, the author has endeavoured to trace the laws
of the diurnal inequality by assuming a similar kind of correspond-
ence with the same theory; and the results have confirmed, in the
most striking manner, the correctness of that assumption. By taking
the moon's declination four days anterior to the day of observation,
the results of comj)utation accorded, with great accuracy, with the
observed heights of the tides : that is, the period employed was the
fifth lunar transit preceding each tide.

In the second section, the observations made on the tides at Sin-
capore from August 1834 to August 1835, are discussed. A diurnal
inequality was found to exist at that place, nearly agreeing in law and
in amount with that at Plymouth ; the only difference being that, in-
stead of four days, it was found necessary to take the lunar declina-
tion a day and a half preceding the tide ; or, more exactly, at the in-
terpolated, or north lunar transit, which intervened between the se-
cond and third south transit preceding the tide. The diurnal inequality
at Sincapore is of enormous magnitude, amounting in many cases to
six feet of difference between the morning and evening tides ; the
whole rise of the mean tide being only seven feet at spring tides, and
the difference between mean spring and neap tides not exceeding two
feet.

In the third section, the author considers the diurnal inequalities
at some other places, and the general law of its progress. The change
which the epoch, (that is, the anterior period at which the moon's de-
clination corresponds to theamountand direction of the inequality,) in
particular, undergoes, is a subject of great interest. At Liverpool,
the epoch is found to be about six days and a quarter ; at Bristol, it
is nearly six days ; and at Leith, it is as much as twelve days. On
the east coast of America, it appears to be zero. On the coasts of
Spain, Portugal, and France, it is successively two, and three days j
and on those of Cornwall and Devonshire, four days 3 thus observing
a tolerably regular augmentation as it is traced along the line of coast
from the shores of the Atlantic to the Firth of Forth, but travelling
more slowly than the other inequalities.

Royal Society. 381

In section fourth, the author treats of certain extreme cases of diur-
nal inequality ; particularly those which produce the phaenomenon of
a single tide in the twenty-four hours : such as that noticed by Capt.
Fitzroy at King George's Sound, on the south coast of New Holland j
and that of Tonquin, referred by Newton to the interference of two
tides arriving by different channels, but probably owing to the ope-
ration of the same law as that which gives rise to the diurnal ine-
quality.

Jn section fifth, the author considers the subject of the mean height
of the sea j that is, the height midway between low water and high
water each day : and arrives at the result that it is very nearly con-
stant.

March 16. — A paper was read, entitled, "On the Tides." By
John William Lubbock, Esq., F.R.S., &c.

Since the author presented his last paper on the tides to the Society,
his attention has been directed to ascertain the three following points:
namely, 1st, Whether, from the discussion of the Liverpool observa-
tions with reference to a previous transit, these observations present
the same kind of agreement with Bernoulli's theory as those of Lon-
don : 2ndly, Whether, by taking into account a greater number of
observations, the results given in his last paper remain sensibly un-
altered : and 3rdly, Whether the establishment oi the Port of London
varies sensibly in different years; and whether the removal of the old
London bridge has occasioned any difference. In order to elucidate
these points, he procured the assistance of Mr. Jones and Mr. Ruwssell
to compute numerous tables; employing for that purpose a further
sum of money placed at his disposal with this view by the British
Association for the Advancement of Science. The results contained
in the tables here presented, are all laid down in diagrams, on the
same plan as those contained in his last paper, by which means they
are much more readily understood. The author finds that the semi-
menstrual correction for the interval at Liverpool presents the same
agreement with observation as had been before noticed -, while the
form or law of the semi-menstrual correction for the height is also the
same as that indicated by the observations ; but in order to render the
agreement complete it would be necessary to change the epoch, or to
make a slight movement of the theory-curve in the diagrams. This
remarkable difference also obtains in the London semi-menstrual cor-
rection for the height.

The calendar month inequality at Liverpool, considered as result-
ing implicitly from the corrections due to changes in the declinations
of the luminaries, and in the sun's parallax, agrees generally with Ber-
noulli's theory, and with the results deduced from the London obser-
vations given in the author's last paper.

The author finds that the Establishment of the Port of London has
been subject to changes even since the beginning of the present cen-
tury, and he notices the difficulty of predicting the time of high water
with accuracy unless these changes can be accounted for. He also
cites a very ancient Tide Table, from which it would appear that for-

382 Royal Irish Academy,

merly the time of high water at London was an hour hiter than it is
at present.

The Society then adjourned over the Easter recess, to meet again
on the 6th of April.

ROYAL IRISH ACADEMY.

October 24, 1836. — A paper was read, entitled "■ Contributions
to the History of Pyroxylic Spirit, and the derived Combinations."
By Robert J. Kane, M.D. M.R.I.A., Professor of Natural Philo-
sophy in the Royal Dublin Society*.

A paper was also read, " On the laws of Reflexion from Metals."
By James MacCullagh, M.R.I. A., Professor of Mathematics in the
University of Dublin.

The author observes that the theory of the action of metals upon
light is among the desiderata of physical optics, whatever informa-
tion we possess upon this subject being derived from the experiments
of Sir David Brewster. But, in the absence of a real theory, it is
important that we should be able to represent the phaenomena by
means of empirical formulae ; and, accordingly, the author has en-
deavoured to obtain such formulae by a method analogous to that
which Fresnel employed in the case of total reflexion at the surface
of a rarer medium, and which, as is well known, depends on a pecu-
liar interpretation of the sign ^ — 1. For the case of metallic re-
flexion, the author assumes that the velocity of propagation in the
metal, or the reciprocal of the refractive index, is of the form

m{cosx + V - 1 sin;)^)i

without attaching to this form any physical signification, but using
it rather as a means of introducing two constants (for there must be
two constants, m and %, for each metal) into Fresnel's formulae for
ordinary reflexion, which contain only one constant, namely, the
refractive index.

Then if i be the angle of incidence on the metal, and i the angle
of refraction, we have

sin i'=m (cos % + i/ — 1 sin p^) sin j, (1)
and therefore we may put

cos z'=m' (cos ;^' — V — 1 sin p^') cos 2, (2)

if m!^ cos * j = 1 — 2m2 cos2 % sin H + rw* sin *i, (3)

and tan 2y'= — ^- — .-— .. (4)

^ 1 — wi2 cos 2% sin H

Now, first, if the incident light be polarized in the plane of re-

♦ This paper has appeared in our present volume, p. 45 et scq. See
also the Proceedings of the British Association, also in Lond. and Edinb.
Phil. Mag., vol. vii. p. 397— Edit.

Prof. MacCullagh on the Ldiaos of Reflexion from Metals. 38S

flexion, and if the preceding values of sin 2', cos i', be substituted
in Fresnel's expression

sin (i — i')

for the amplitude of the reflected vibration, the result may be re-
duced to the form

a (cos 5 - V - 1 sin S), (5)

if we put

tan tf/ = ^, (6)

tan 5 = tan 2^^/ sin (% + %') 0)

^o^l-sin2v|/cosfa+%^) (8)

1 + sin 2^ cos (x + %')

Then according to the interpretation, before alluded to, of \/ — 1
the angle S will denote the change of phase, or the retardation of
the reflected light ; and a will be the amplitude of the reflected
vibration, that of the incident vibration being unity. The values
of m', x', for any angle of incidence, are found by formulae (3), (4),
the quantities tw, p^, being given for each metal. The angle %'is
very small, and may in general be neglected.

Secondly, when the incident light is polarized perpendicularly to
the plane of reflexion, the expression

tan (i — i')
tan (2 + i')'
treated in the same manner, will become

a (cos S' - V"iri sin ^), (9)
if we make

tan y}f' z=m m', (10)

tan ($' = tan 2iJ/' sin (x - x')^ (10

^,^_l - sin 24^' cos (y - %^) . ,^2^

1 + sin 2^' cos (%-%')' ^ ^

and here, as before, S' will be the retardation of the reflected light,

and a' the amplitude of its vibration.

The number m = — may be called the modulus^ and the angle %

the characteristic of the metal. The modulus is something less than
the tangent of the angle which Sir David Brewster has called the
maximum polarizing angle. After two reflexions at this angle a ray
originally polarized in a plane inclined 45° to that of reflexion will
again be plane polarized in a plane inclined at a certain angle <p
(which is 1 7° for steel) to the plane of reflexion ; and we must
have

tan^=^*. (IS)

Also, at the maximum polarizing angle we must have

5' - 5 = 90°. (14)

S84> Royal Irish Academy.

And these two conditions will enable us to determine the constants
M and % for any metal, when we know its maximuni polarizing angle
and the value of (p ; both of which have been found for a great
number of metals by Sir David Brewster. The following table is
computed for steel, taking m = 34^, % = 54°.

i

^

J'

a2

a'2

i(a°- + a"0

0°

27°

27°

•526

•526

•526

30

23

31

•575

•475

•525

45

J9

38

•638

•407

•522

60

13

54

•729

•308

•518

75

7

98

•850

•240

•545

85

2

152

•947

•491

•719

90

0

180

!•

1-

1-

The most remarkable thing in this table is the last column, which
gives the intensity of the light reflected when common light is in-
cident. The intensity decreases very slowly up to a large angle of
incidence, (less than 75°,) and then increases up to 90°, where there
is total reflexion. This singular fact, that the intensity decreases
with the obliquity of incidence, was discovered by Mr. Potter, whose
experiments extend as far as an incidence of 70°*. Whether the
subsequent increase which appears from the table indicates a real
phaBnomenon,or ari.ses from an error in the empirical formulae, can-
not be determined without more experiments. It should be ob-
served, however, that in these very oblique incidences Fresnel's
formulae for transparent media do not represent the actual phaeno-
mena for such media, a great quantity of the light being stopped,
when the formulae give a reflexion very nearly total.

The value of ^' — 5, or the difference of phase, increases from 0°
to 180°. When a plane-polarized ray is twice reflected from a me-
tal, it will still be plane- polarized if the sum of the values of ^' — J
for the two angles of incidence be equal to 180^

It appears from the formulae that when the characteristic ;)^ is
very small, the value of ^' will continue very small up to the neigh-
bourhood of the polarizing angle. It will pass through 90°, when
w m' = I ; after which the change will be very rapid, and the value
of 5' will soon rise to nearly 180°. This is exactly the phaenomenon
which Mr. Airy observed in the diamondf.

Another set of phaenomena to which the author has applied his
formulae are those of the coloured rings formed between a glass
lens and a metallic reflector ; aad he has thus been enabled to ac-
count for the singular appearances described by M. Arago in the
Memoires d^ Arcueil,iom.\iu, particularly the succession of changes

• A notice of Mr. Potter's experiments will be found in Phil. Mag. and
Annals, vol. viii. p. 60. — Edit.

t M r. Airy 's paper, in which this phaenomenon is described, appeared in
Lond. and Edinb. Phil. Mag., vol. ii. p. ^0.— Edit.

Roi/al Irish Academy, 385

which are observed when common light is incident^ the intrusion oF
a new ring, &c. But there is one curious appearance which he
does not find described by any former author. It is this. Through
the last twenty or thirty degrees of incidence the first dark ring,
surrounding the central spot which is comparatively bright, remains
constantly of the same magnitude ; although the other rings, like
Newton's rings formed between two glass lenses, dilate greatly with
the obliquity of incidence. This appearance was observed at the
same time by Professor Lloyd. The explanation is easy. It de-
pends simply on this circumstance, (which is evident from the
table,) that the angle 180° — 5, at these oblique incidences, is nearly
proportional to cos i.

As to the index of refraction in metals, the author conjectures

that it is equal to .

cos p^ ^

Rev. Robert Gage exhibited specimens of Coal and Ironstone,
recently found in Rathlin Island, on the north coast of Ireland.

Nov. 30, 18.^(;. — Sir William Betham exhibited to the Academy a
specimen of the ancient brazen ring money, found in the county of
Monaghan, and also a piece of cast iron, found with many others, in
boxes, on board a vessel wrecked on the coast of Cork last summer.
This vessel was bound to Africa, where it is stated the pieces in
question pass for money. They are so similar in shape and size to
the ancient specimens, that there can be no reasonable doubt of the
identity of their uses ; and thus the theory advanced in the paper
referred to is strongly confirmed.

Sir William Betham also read an extract of a letter from a friend,
in which it was stated, that gold rings, exactly formed like those
found in the Irish bogs, — that is, of gold wire turned into the form
of rings, but not united at the ends, — pass current at this moment
as money in Nubia and Sennaar.

The Dean of St. Patrick's exhibited two bronze specimens of the
first-mentioned articles found in Italy, one of which was encrusted
with crystals of carbonate of lime.

The following papers were read : 1. "On the Affinity of the
Hiberno-Celtic and Phoenician Languages." By Sir William
Betham, M.R.I.A., Secretary of Foreign Correspondence. An ab-
stract of this paper appears in the " Proceedings " of the Academy,
No. L

2. '• On the Propagation of Light in Uncrystallized Media." By
the Rev. H. Lloyd, F.R.S., M.R.I. A., Professor of Natural Philo-
sophy in the University of Dublin.

The objects of the author have been — 1. to simplify and to deve-
lop that part of M. Cauchy's theory which relates* to the propaga-
tion of light in an aethereal medium of uniform density; 2. to ex-
tend the same theory to the case of the aether inclosed in uncry-
stallized substances, taking into account the action of the material
molecules.

Some of the simplifications adopted in the first part of these in-

Third Series. Vol. 10. No. 62. May 1837. 3 D

386 Royal Irish Academy,

quiries suggest themselves naturally. Thus the axes of symmetry
of the medium are taken as the axes of coordinates, and the direc-
tion of propagation is assumed to coincide with one of these axes.
By these suppositions the differential equations of motion are reduced
to a very simple form ; and it is manifest that the assumptions
themselves involve no real limitation of the problem. The well-
known expressions for the component displacements are deduced by
the integration of these equations. The following is that in the di-
rection of the axis of x ;

^ = a cos {ut — kz •\- (i)\
in which

2»r ; 2*
T A

r being the period of vibration, and X the length of the wave. These
quantities are connected by a relation given by the method of in-
tegration.

The preceding formula, however, is not the most general form of
the expression for the displacement. It is found that in certain
cases the integral becomes

J = ae~^^ cos {ut — gz -{■ a).

From this expression it follows that the amplitude of the displace-
ment, and therefore the intensity of the light, decreases in geome-
trical progression, as the distance increases in arithmetical progres-
sion ; and as the constant h is in general a function of m, or of the
colour, the differently coloured rays will be differently absorbed*
The complete value of ^ being the sum of a series of terms similar to
the preceding, it is manifest that we have here a satisfactory account
of the apparently irregular distribution of light in the absorbed
spectrum. To explain the absolute deficiency of the light at cer-
tain points, it is only necessary to admit that the function h varies
in certain cases rapidly with moderate changes in w, and becomes
very great for certain definite values of that quantity.

The preceding integral has been already obtained by M, Cauchy,
in a valuable memoir recently printed in lithograph. I'he method
employed by the author seems, however, to be fundamentally dif-
ferent from that of M. Cauchy ; and in fact he was led to this form
of the integral by other considerations before he was aware that he
had been preceded in the deduction.

The remainder of the present communication is taken up with
the discussion of the relation between the coefficients u and A;, which
expresses the law of dispersion. Following M. Cauchy*, the au-
thor has transformed this relation by converting the triple sums into
triple integrals ; and he has found that, by applying this transfor-
mation at an earlier stage of the investigation, the resulting relation
is deduced with great simplicity.

♦ Nouveaux Exercices dc Mathematiqucs Livraison 7"*.

Royal Irish Academy, 387

The relation between u and Ar, for the vibrations in the plane of
the wave, has already yielded to M. Cauchy the probable result,
that the molecules of the aether repel one another according to the
inverse fourth power of the distance. When this law of force is
substituted in the corresponding relation for the normal vibration,

the author finds that the resulting value of — , or of the velocity of

propagation, is infinite ; so that the normal disturbance is propa-
gated instantaneously , and gives rise to no wave. Thus the hypo-
thesis of transversal vibrations seems to be established on theore-
tical grounds.

The author finally gives reasons for concluding that the theory,
in its present form, is insufficient to explain the phaenomena of
light in bodies ; and that it becomes necessary in this case to take
into account the action of the material molecules. This extension
of the theory will be given in a future communication.

3. " On the Composition of Thebaine." By Robert J. Kane,M.D.,
M.R.I. A., Professor of Natural Philosophy in the Royal Dublin
Society.

The author gave an account of the analysis of the vegetable alka-
loid thebaine (pararaorphine) which had been discovered in opium,
and of which the analysis by Pelletier and Couerbe gave discordant
results. With a specimen which had been prepared by Apothecary
Merck of Darmstadt, Dr. Kane obtained the following formula Cg^
N^ Hgg O3, (Berzelian atoms,) and giving the per cent, composition :

25 Carbon = 74-57 = 1910-925

2 Azote = 6-89 - 177*036
28 Hydrogen = 6*83 - 174-714

3 Oxygen = 11*71 - 300*000

lOO'OO 25Q2'Q75

Owing to the circumstance of the salts of this base with the mineral
acids being uncrystallizable, the atomic weight obtained by analysis
could not be synthetically confirmed.

Professor Kane read likewise an extract of a letter from Pro-
fessor Liebig, of Giessen, communicating some new results of che-
mical analysis.

It was resolved, on the recommendation of Council, that the
" Proceedings of the Royal Irish Academy" be printed every month
during its sittings, for the use of its members. The " Proceedings"
to be under the management of the Council, and to contain, — 1. Abs-
tract^ of the larger papers read to the Academy. 2. Minor com-
munications, not intended for the Transactions, printed more at
length. 3, Notices of the election of members, of presents received,
and of all other matters of general interest transacted at the meet-
ings of the Academy.

3D2

388 Geological Society.

GEOLOGICAL SOCIETY.

[The Address of the President, Charles Lyell, jun., Esq., at the Anniver-
sary, 1837. — Continued from p. 31G.]

We are indebted to Mr. Austen for a desc ription of the South of
Devonshire between the river Ex and Berry Head, and between the
coast and Dartmoor, a district consisting of transition rocks, new
red sandstone, greenstone, and trap. His speculations on the origin
of the different formations and the causes which gave rise to the
existing features in the physical geography of the country display
much talent and are full of instruction*.

The structure of Devonshire has also furnished a fertile fieldof in-
quiry to Messrs. Sedgwick and Murchison since our last Anniversary.
They have attempted the difficult task of establishing a classifica-
tion of the older rocks so largely developed in that county. In every
geological map hitherto published of Devonshire, all the stratified
deposits of higher antiquity than the new red sandstone had been
represented by one common colour, the limestones being all included
as integral parts of one great formation called graywackef . But
these gentlemen, after examining this region, announced at Bristol
to the geologists assembled at the Meeting of the British Association,
that the great mass termed graywacke, and previously undivided,
comprised in it several formations of great thickness, ranging in
age from the Cambrian system of Professor Sedgwick up to the
true carboniferous series inclusive. The first groups mentioned by
them in ascending order are the Cambrian and Lower Silurian,
which great mass contains many distinct courses of limestone ; and
is separable into several formations, distinguishable from each other
by stratigraphical position and by lithological and zoological cha-
racters.

There appears, however, to be a great hiatus in the succession of
rocks in Devonshire, as compared to South Wales, there being no
traces of the upper Silurian strata, nor of the old red sandstone,
nor even of the mountain limestone in its ordinary aspect. On the
contrary, the next group met with in ascending order, is a culmi-
ferous series, the base of which distinctly reposes upon the above-
mentioned ancient rocks. This culmiferous deposit, far from ap-
pearing as a mere band, or at detached points, occupies about one
third of the large county of Devon, and a considerable adjacent
part of Cornwall ; its southern boundary ranging from Exeter on
the east, by Launceston, to St. Gennis in Cornwall on the west ; its
northern frontier running by Barnstaple and South Moulton to near
Wellington in Somersetshire. These culmiferous beds are shown to

* [An abstract of Mr. Austen's paper appeared in Lond. and Edinb. Phil.
Mag. vol. ix. p. 495. — Edit.]

f The Abstract of the Report of Messrs. Sedgwick and Murchison, pub-
lished with a section in the Athenaeum, August, 1836, and in other scientific
joumals, is the same as that written for insertion in the Proceedings of the
Association. From that document, and from a written explanation of their
views, whicb I obtained from the authors, the present observations are de-
duced.

Mr. Lyeirs Address. 389

contain thick beds of limestone, entirely dissimilar in structure and
fossil contents from any limestones of the underlying " grauwacke,"
in which they had previously been merged. The culm measures
consist of grit, sandstone, shale and limestone; and these rocks, it is
said, are never affected by a slaty cleavage like the lower Silurian
and Cambrian rocks on which they rest. From this character, as
well as from their prevailing mineralogical structure and imbedded
fossil plants, the authors regard the culmiferous formation of Devon
as perfectly identical in age with other coal-fields, and as more par-
ticularly analogous to the culm-bearing strata of Pembrokeshire ;
a part of which also once passed for "grauwacke," but Mr. Mur-
chison has recently shown that it belongs to the South Welsh coal-
field, which is known by all geologists to rest upon mountain lime-
stone.

Thus referred to the age of our ordinary coa(l, these strata of North
Devon are further proved to lie in a great trough, their southern edges
being turned up against the granite of Dartmoor, where they acquire, in
contact with the granite, when traversed by elvan dykes, many
characters of the metamorphic rocks, or those commonly termed
primary. The phaenomena of interference and alteration at the
junction are such as to give a comparatively modern date for the
eruption of the Dartmoor granite, and to explain why so much dif-
ficulty and ambiguity has prevailed in determining the age of some
of the altered culm beds.

Among other points which this survey of Professor Sedgwick and
Mr. Murchison has settled, so far as Devon is concerned, is one of
the highest theoretical interest, and on which for more than two
years the Society has been anxiously desiring more accurate infor-
mation; 1 allude to the true stratigraphical position of certain
shales near Bideford in North Devon, containing fossil plants of the
same species as those which are found abundantly in the coal. I may
first remind you that a discussion had previously arisen respecting
the alleged discovery by Mr. Weaver of anthracite, with the usual
carboniferous plants, in the graywacke or transition rocks of Ire-
land*. Notwithstanding the value justly attached to the opinion of
so experienced and long-practised an observer, your Council hesi-
tated to print his statement, and requested him to reexamine the
ground. At the same time Mr. Griffith, to whom we are looking
for the publication of a Geological Map of Ireland, had come to a
different conclusion, and Mr. Weaver having been induced to repeat
his observations, became convinced that he was in error, and has
since studiously availed himself of every opportunity of announcing
this change in his views.

You are aware that as yet in the British islands, scarcely any vege-
table impressions have been met with in rocks more ancient than the
carboniferous strata above the old red sandstone, so that we know not
what species of plants belong to the graywacke or transition group. We
can only presume from analogy that since the shells, corals, and other

* Phil. Mag. and Annals, vol. viii. p. 147.

390 Geological Society.

organic remains of that ancient group differ from those found above
the old red sandstone, the plants also, if ever discovered, will differ
as greatly. Considerable surprise was therefore excited when,
during the Presidentship of my predecessor in this chair, a letter
was read, addressed to him from Mr. De la Beche, stating that he
had found, near Bideford in North Devon, many well known coal
plants in the lower greywacke, or far down in the transition series*.
Such of the plants as were determinable had been identified by
Professor Lindley with species characteristic of the true coal
measures, and which had never been found elsewhere below the
coal. The anomaly, therefore, in the supposed position of these
fossils was so great, that between the ordinary geological site of
such remains, and that in which they were here inferred to present
themselves, there would be interposed if the series were complete
the whole of the old red sandstone, and at least the two upper forma-
tions of the Silurian system. When this point was considered, I
expressed to the Society my opinion, in common with Mr. Mur-
chison, as to the insufficiency of the proofs relied on by our
Foreign Secretary, and we felt that we had a right to call for more
conclusive evidence. The simple fact of shales having been found
charged with true coal plants, raised so strong a presumption in
favour of their belonging to the regular carboniferous series, that
the burthen of proof rested with him who wished to assign to them
either a higher or lower position. Our scepticism was regarded
by Mr. Greenough as implying too marked a bias for a preconceived
theory, and this he afterwards hinted in his Anniversary Addressf.
I may affirm, however, that in the first place it implied on my part
no distrust of Mr. De la Beche's skill or experience in geological sur-
veying, and that had Professor Sedgwick and Mr. Murchison ad-
vanced a similar opinion on analogous proofs, I should equally have
withheld my assent. Suppose, for example, they had announced to
us that they had found fossil fruits and leaves identical with those of
Sheppey in strata of the age of the white chalk with flints. I should
have demanded from them, in corroboration, the most clear, un-
equivocal, and overwhelming evidence. If it were a region of dis-
turbed and vertical strata, I should expect them first to have re-
sorted in vain to every hypothesis of inverted stratification with a
view of explaining away such an exception to the general rule.

I might perhaps be told that we are unacquainted with the flora
of the upper cretaceous period, and I admit that we are as ignorant
of it as of that which belonged to the transition period j but when
we consider the contrast of the shells and other fossils of the
chalk and London clay, we naturally anticipate that if plants are ever
found of the precise age of our chalk with flints, they will not prove
to be of the same species as those of the Sheppey clay. There
is a like presumption from analogy against the conclusion that the
same vegetation continued to flourish on the earth from the period
of the lower greywacke to that of the coal, because we know that

* Lond. and Edinb. Phil. Mag., vol. vi. p. 67. f Ibid., vol. vii. p. 162.

Mr. LyelPs Address, 391

in the course of the intervening epochs the testacea, zoophytes, fish,
and other classes of organic beings were several times changed.

In regard to the proofs relied on by Mr. De la Beche, I should
observe that he never attempted to show that the plant-bearing
shales at Bideford were interstratified with rocks charged with
shells or other fossils known to belong to rocks older than the old
red sandstone.

Since writing the above sketch of the different views recently
published of the structure of Devonshire, I have received a letter
from Mr. De la Beche, from which I am happy to learn, that it is
his intention before concluding his report on the Ordnance Map
of Devon, to reexamine Devonshire. He is far, he says, from
pretending that his first views were perfect, and if he finds rea-
son to modify any of them, he shall not hesitate to announce the
change of opinion. In the mean time he no longer contends that
the culmiferous strata are referable to the lower graywacke, and
considers the point of difference to lie within a narrower compass,
namely, whether the culm beds are to be considered as upper gray-
wacke or coal. This question, on which he is not yet satisfied, evi-
dently appears to him of much less theoretical importance than, I
confess, it does to me. It is fair, however, that I should state the
arguments which influence his mind. If the plants, he says, found
at Bideford in the culmiferous series should belong to strata more
ancient than the old red sandstone the fact would not stand alone,
for he has lately received a letter from M. Elie de Beaumont, de-
tailing analogous phaenomena in Brittany. It is stated that the grey-
wacke there closely corresponds in general character with that of
Devon, the upper part like the Devonian series containing anthra-
cite. With this anthracite or culm are found at Montrelais, Chatelai-
son, and other places, fossil plants, the greater part of which are
identical with those in the coal measures ; but there are others which
have not hitherto been detected in the latter rock. Patches of true
coal measures rest in unconformable position upon these upper
graywacke beds of Brittany. Now I regret that I have not seen
any printed account of the geology of this part of France ; for until
we learn whether the plants in question are associated with true Si-
lurian fossils, the testimony is quite incomplete. We know not,
for instance, whether the plant- bearing series in question is old red
sandstone or a Silurian formation, or wliether it is a lower part of
the true carboniferous system of which the strata had been disturbed
before a higher portion was superimposed.

Similar remarks hold in regard to the observations made by
M. Virlet in the Dictionnaire d'Hist. Naturelle, where in his late
article " De I'Origine des Combustibles Mineraux," he speaks of
certain carboniferous deposits of Ireland, (those alluded to by Mr.
Weaver before mentioned,) as well as others examined by M. Voltz
in the Black Forest, also the culm beds of Brittany, and those of
the department of La Sarthe, as all belonging in age to the newest
transition formations, " terrains de transition les 'plus recens.''*

Mr. De la Beche alludes to another discovery of coal plants

392 Geological Society,

implying as great an anomaly as that which he had imagined to
occur in Devonshire, and by which he was himself once led into
error during an Alpine excursion, about eighteen years since, when
he met with coal plants in the schists of the Col de Balme, in
Switzerland. He then inferred that the beds belonged to the true
coal measures, but M. Elie de Beaumont afterwards proved them
to be lias ; that is to say, he identified them with other rocks not far
distant in the Alps, which were shown to be lias by containing Belem-
nites and other fossils. Mr. De la Beche was at first sceptical on the
point, but after revisiting the Alps, he came round to the same opi-
nion. Having therefore been in one instance misled by relying on
the fossil vegetables of the coal as affording a good chronological
test, he naturally attached but small value to the same testimony as
a criterion of the age of another set of rocks in Devonshire. Now
you will easily understand that a geologist, who is once persuaded
that the same plants flourished in European latitudes from the pe-
riod of the true coal to that of the lias, will be ready to concede
without difficulty the probable existence of the same plants at an
era long antecedent to the coal. We know that between the depo-
sition of the coal and the lias there were successive revolutions in
the races of animals which inhabited the waters, the zoophytes,
mollusca, fish, and, as far as we know them, the reptiles having been
changed again and again ; so that the fossils of the mountain lime-
stone differ from those of the magnesian limestone or zechstein,
these again from the organic remains of the muschelkalk, and these
last from those of the lias. If we are to believe that the same
plants survived on the land, while such fluctuations in animal life
occurred in the waters, why should we not imagine the longevity of
the same species to have been still greater, so that they began to
exist even before the deposition of the old red sandstone ? But let
me remind you that botanists have been led to very different con-
clusions respecting the laws governing the distribution of fossil ve-
getables from the study of undisturbed districts. You are not
ignorant that the strata of the Alps are involved in extreme confu-
sion and complexity, mountain masses having been completely
overturned and twisted, so that the same set of strata have been
found at the top and bottom of the same section separated by seve-
ral thousand feet of beds belonging to an older formation. So
obscure is the order of position in Alpine geology, that the cretaceous
and greensand series have been classed by experienced geologists
as more ancient than the oolite, under which, in point of fact, they
occasionally lie.

Professor Studer, in his work on the Bernese Highlands, after
years of personal investigation, has published a map in which he
has given a coloured ground plan without venturing to commit him-
self by sections, or a table of the regular order of superposition.

After devoting a summer to the investigation of the same portion
of Switzerland, with the advantage of Mr. Studer's map and work,
I was unable to satisfy myself that I had found a key to the classi-
fication or superposition of the formations, so enormous is the scale

Mr. Lyell's Address. 393

on which they have been deranged. I collected fossil plants on the
Col de Balme, but I have not examined the precise localities further
to the west appealed to by M. de Beaumont. I am far, therefore,
from denying his facts or inferences, hoping at some future period
more carefully to inquire into the evidence on the spot. No one, I
am aware, is more desirous that others should visit the southern
Alps and verify or criticise his facts than M. de Beaumont. Mean-
while I am reminded of an expression of our mutual friend M. von
Buch. When I related to him some geological phaenomena which
surprised him ; ** I believe it," he said, " because you have seen
it, but had I only seen it myself, I should not have believed it."

But to conclude, and to recall your attention to the structure of
Devonshire, you will perceive that Mr. Murchison and. Professor
Sedgwick have endeavoured, and I think successfully, to work a
great reform in the classification of the ancient rocks of that
country, by applying to them the arrangement which they had pre-
viously made for the deposits termed by them Cambrian and Lower
Silurian in Wales and the adjoining parts of England. According
to their survey and sections the coal plants of Bideford, so far
from constituting any anomaly, so far from affording any objection
to the doctrine that particular species of fossil plants are' good tests
of the relative age of rocks, do in reality from the place which they
occupy, confirm that doctrine ; for the culmiferous rocks distinctly
overlie the so-called grauwacke, and are not referable to any of the
well-defined and normal types, which compose the old Red Sand-
stone and Silurian System.

I shall now pass on to the consideration of other memoirs on En-
glish Geology. The limestone which the Germans call muschelkalk,
and the numerous fossils which are peculiar to it, have not yet been
detected in England in any part of that great series of beds which
intervene between the lias and the coal. In those parts of Germany
where it occurs, it divides the beds of red marl and sandstone which
occupy that great interval into two divisions, the upper of which
is called keuper, and the lower hunter sandstein. In the absence
of the muschelkalk in this country, it has been impossible for us
to separate our new red sandstone into two well-defined masses ;
but Dr. Buckland considers that certain portions of the upper beds
in Warwickshire and elsewhere may be identified with the keuper
by their mineral character, and near Warwick by the remains of a
Saurian, which he believes to be of the genus Phytosaurus, a genus
characteristic of the keuper of Wirtemberg.

An examination in the South-east of England of the strata usually
termed plastic clay, has led Mr. John Morris to offer several new,
and as they appear to me, judicious suggestions in regard to the
classification of these beds. It is well known that wherever the
tertiary strata are seen in immediate contact with the chalk, they
consist of alternations of sand, clay, and pebbles, and in some
few places a calcareous rock, — all these varying greatly in their
thickness, and in their order of succession in different places.
Mr. Morris divides those of Woolwich into two parts, and states

Third Series. Vol. 10. No. 62. Ma^ 1837. 3 E

S9^ Geological Society,

that the upper is characterized by a mixture of marine and fresh-
water shells, the freshwater genera being Cyrena, Neritina, Me-
lanopsis, and Planorbis. The lower division contains exclusively
marine shells. The author refers this intermixture to the in-
flux of a river into the sea, in which the London clay was formed.
Mr. Morris considers the Bognor strata, which rest immediately
upon chalk, as the equivalents of the lower Woolwich deposit, ob-
serving that the shells agree with those of the London clay. These
remarks seem to confirm the conclusion to which he had been pre-
viously led by the grand section at Alum Bay in the Isle of Wight,
namely, that the beds usually styled plastic and London clays be-
long to one zoological period.

MINERAL VEINS.

Your attention has been called to the origin of mineral veins by
Mr. Fox, who has endeavoured to explain why so large a propor-
tion of the metalliferous veins in England and other parts of the
world should have an east and west direction. He supposes fis-
sures filled with water, containing sulphurets and muriates of cop-
per, tin, iron, and zinc in solution, through which currents of voltaic
electricity are transmitted. The metals separated from their sol-
vents by this action are deposited in the veins, and most abundantly
in veins running at right angles to the direction of the earth's mag-
netism ; for as the magnetic currents of the earth pass from north
to south, they cause those of electricity to move east and west, al-
though considerable deviations from this direction must be occa-
sioned in the course of geological epochs by variations in the mag-
netic meridian*.

Since Mr. Fox first ascertained the existence of electric currents
in some of the metalliferous veins in Cornwall-j-, Mr. Henwood has
made many experiments on the same subject, together with obser-
vations on the distribution of metallic and earthy minerals in veins.
He considers the results obtained by him to be in a great degree op-
posed to the theory of Mr. Fox J.

Mr. Fox conceives the fissures in which metalliferous substances
occur, to have been at firstsmall and narrow, and to have increased gra-
dually in their dimensions. This doctrine has also been propounded
in a work with which you are probably familiar, and from which I
have derived much instruction, 1 mean M. Fournet's Essay on Me-
talliferous Deposits. This Essay was originally included in the 3rd
volume of M. Burat's continuation of D'Aubuisson's Treatise on
Geology (1835), but it is now published separately, and gives the
clearest general view which I have seen of the application of geo-
logical theories to phaenomena observed in mining. It is written

• [Mr. Fox's paper was noticed in Lond. and Edinb. Phil. Mag., vol. ix.
p. 387.— Edit.]

t Phil. Trans. 1830, p. 399.

X See Mining Journal,. Supplement 9. p. 34, December 1836, and Annals
of Electricity, No. 2. vol. i. on Electric Currents, &c. by W. T. Henwood,
Esq.

Mr. Lyell's Address. 395

by one who has acquired much practical knowledge as a miner, and
who is well versed in chemistry and mineralogy*.

Werner, when he pubUshed his justly celebrated Essay on Mine-
ral Veins, had come to the conclusion that the same rent, after being
wholly or partially filled, has sometimes been reopened; and M.
Fournet has endeavoured more fully to explain the successive dila-
tation of the same veins at distinct periods. He has given examples
in mines worked under his direction in Auvergne, in which the sul-
phurets of iron, copper, lead, and zinc, besides quartz, barytes, and
other minerals, seem evidently to have been introduced at different
periods by chemic d action accompanied by new fractures and dis-
locations of the rocks, and the widening of preexisting fissuresf .

You will find in M. Fournet's treatise a copious analysis of a great
variety of books on mining, besides a detail of facts which have
fallen under his own observation. He has described first those
veins which are decidedly connected with rents produced in rocks
by mechanical movements, and which are supposed to have been
chiefly filled from below by sublimation, more or less obviously con-
nected with volcanic action. He afterwards passes on to the con-
sideration of those masses which have been called stockwerks by
the Germans, which are imagined by some to have their origin in
the contraction of granite, porphyry, and other rocks as they cooled,
numerous rents being then formed, in which metallic particles were
concentrated. In treating the subject in this order the author ap-
pears to me to have followed the most philosophical course, begin-
ning with cases of undoubted rents of mechanical origin filled with
minerals and metals introduced by sublimation, and then carry-
ing with him as far as possible the light derived from these
sources to dissipate a part of the obscurity in which all theories re-
specting the nature of Plutonic rocks and their minerals must, I fear,
be for ever involved. Much will still remain unexplained; but
those who proceed in an opposite direction often throw doubt and
confusion upon the simplest phaenomena, as has sometimes happened
in an analogous case, when geologists have begun with the exami-
nation of granite and granite veins, and have then endeavoured to
apply the ideas derived from this study to the trap rocks and vol-
canic dykes.

Among the most interesting conclusions deduced by M. Fournet
from his examination of the mining districts of Europe, I may men-
tion the modern periods at which the precious metals apjjear to have
entered into some veins: thus, to select a single example, some veins
of silver of Joachimsthal in Bohemia are proved to have originated
iu the tertiary periodj.

FOREIGN GEOLOGY.

Among the researches into the geology of foreign countries in
which our members have been recently engaged, J have great

* Etudes sur les D6pots Metalliferes, par M. I. Fouruet.
.f See " Etudes," &r. Section 3.
J See " Etudes," &c. Section 2.
3E2

896 Geological Society,

pleasure in alluding to the labours of Mr. H.E.Strickland and'
Mr. Hamilton in Asia Minor*. These gentlemen first examined the
neighbourhood of Constantinople, and found on both sides of the
Thracian Bosphorus an ancient group of fossiliferous strata, con-
sisting of schist, sandstone, and limestone. From the character of
the fossils it is inferred that these rocks may probably be the equi-
valents of the upper transition or Silurian strata of England. The
shells belong to the brachiopodous genera Spirifer, Producta, and
Terebratula, with which the remains of corals and Crinoidea were
associated, and fragments of a Trilobite.

The rarity of any fossiliferous deposits of higher antiquity than
the old red sandstone in any of the countries bordering the Mediter-
ranean, or indeed to the south of the Alps and Pyrenees, lends con-
siderable interest to this observation. In their way through France,
our travellers examined the well-known region of extinct volcanos
in Auvergne, and afterwards found a counterpart to it in the Cata-
cecaumene, a district in Asia known by that name in the time of
Strabo, from its burnt and arid appearance. Some of the volcanos
in Asia are of very modern appearance, although no notice of their
eruptions falls within the limits of history or tradition. The vol-
canic hills rise partly through lacustrine limestone in the Valley of
the Hermus, and partly cover the slope of the schistose hills which
hound it to the south. There are about thirty older cones, worn by
time, and of which the craters are efiaced or only marked by a slight
depression; and three newer cones, which preserve their characters
unaltered, the craters being perfectly defined and the streams of
lava still black, rugged, and barren. Here, as in the country of
corresponding structure in France, we find streams of lava following
the course of existing valleys, and yet frequently cut through by
rivers. We find also a tertiary freshwater formation, sometimes
resembling chalk with flints, like that of Aurillac in France, and
forming detached hills capped with basalt, while more modern lavas
have flowed at the base of the same hills. The extent of this ana-
logy will be best appreciated by those who compare Mr. Strick-
land's drawings with Mr. Poulett Scrope's masterly illustrations of
the French volcanic region.

The countries watered by the rivers Meander and Cayster are de-
scribed as having a simple geological structure. There are granitic
rocks, with saccharine marble, there are also hippurite limestone and
schist, and tertiary deposits unconformable to these, besides igneous
rocks of various ages. The tertiary formations are chiefly lacustrine,
and occur in nearly every large valley. They are composed of hori-
zontal beds of calcareous marl and white limestone, in which are
layers and nodules of flint; they also consist of sandstone, sand, and
gravel.

The only representative of the secondary rocks of Europe is
termed by Mr. Strickland "hippurite limestone", which appears to

[* An abstract of Mr. Strickland's paper has appeared in our present vo-
lume, p. 68. — Edit.]

Mr. LyelPs Address. 397

be very sterile iti fossils. In this respect and in its other characters
it agrees with that great calcareous formation described by MM.
Boblaye and Virlet in their splendid work on the Geology of the
Morea*. According to these French geologists, three quarters of
the Peloponnesus are occupied by a compact limestone several
thousand feet thick, in which they could discover scarcely any or-
ganic remains, except a few hippurites and nummulites, but which
is supposed to be the equivalent of our chalk and oolites. Nothingj
they say, can be more monotonous in character than this calcareous
mass in the South of Europe, which appears to represent the larger
part of our upper secondary formations of the North, where the
rocks are so varied in lithological aspect and so distinguishable from
each other by their well-preserved Ibssils.

Ancient fossiliferous strata resembling those of the neighbour-
hood of Constantinople are said to be largely develoj)ed in the
Balkan, a mountain chain of which we may soon expect to receive
information from the pen of M. Ami Boue. That indefatigable
geologist has already explored a large part of Servia, a country of
whose physical and moral condition we are perhaps more ignorant
than of any other in Europe, and he is rapidly extending his sur-
vey over various parts of the Turkish empire, to the examination
of which he proposes to devote several years. Meanwhile our late
Secretary, Mr. Hamilton, is continuing, with great zeal, his investi-
gation of the borders of the Black Sea and other parts of Asiatic
Turkey.

In a paper on the structure of part of the Cotentin near Cher-
bourg, the Rev. W. B. Clarke describes that country as consisting
of hills or ridges of quartz rock alternating with valleys of slate oc-
casionally associated with syenite and greenstone, which appear to
be of posterior origin. A curious fact is mentioned : the quartz
rock splits naturally into irregular masses, which have, nevertheless,
some angles of fixed dimensions, namely, 103°, 64", and 83". Frag-
ments of a green variety of schist exhibit the same angles under the
same circumstances of position, proving that similar causes had
acted on the two formations en masse, the same sets of joints, lines
of stratification, and cleavage being found in both. Besides these
facts, which are illustrated by diagrams, the author mentions others
calculated to throw light on the cleavage and jointed structure of rocks.

PROOFS OF MODERN ELEVATION AND SUBSIDENCE.

Under this head I shall first consider several notices of beds of
gravel, sand, clay, and marl, containing recent marine shells, which
have been observed in various parts of Great Britain, a subject very
frequently brought before our notice of late years. Deposits of this
kind have been found by Dr. Scouler in the vicinity of Dublin,
where they rise to the height of 80, and in some places of even 200

* Paris, 1833, in folio. It is to be regretted that this work cannot be
procured separately from other folios containing the scientific information
collected during the French expedition to the Morea.

398 Geological Society.

feet above the level of the sea. Besides marine sliells of existing
species, he has ascertained that some of the lower beds of this for-
mation contain bones of the extinct Irish elk, by which we learn
that this quadruped, although belonging to a comparatively modern
period, and found in peat-mosses, had nevertheless begun to inhabit
this part of the world at a period anterior to some of the last changes
in the position of land and sea, changes which are proved by the
upraised shelly beds just alluded to. Now Professor Nilsson of Lund
in Sweden, although ignorant of these facts, had remarked to me that
some great alteration must have occurred in the shape and extent
of dry land and sea in Great Britain and the surrounding parts sub-
sequently to the time when the Irish elk existed, otherwise so many
entire skeletons of so large an herbivorous quadruped as the
Cervus megaceros^ would not have been found in so small an island
as the Isle of Man. That island may at no remote geological pe-
riod have been united to the main land, and may have since been
separated from it by subsidences, on a scale equal to the elevations
of which there is such clear evidence in Ireland and elsewhere.

Changes in the relative level of land and water, in the estuary of the
Clyde, are indicated by facts described in another paper by Mr. Smith
of Jordan Hill, near Glasgow. Superficial deposits, in which a great
number of marine shells of recent species are imbedded, are found on
the banks of the Clyde below Glasgow, at the height of SO or 40 feet
above the sea. I had myself an opportunity of verifying during the
last summer several of these observations of Mr. Smith, and found
equally clear proofs that the Island of Arran had participated in the
upward movement, so that a circle of inland cliffs may be traced all
round that island, between the base of which and the present high-
water mark a raised beach occurs, and in some places beds of marine
marls, formed of recent shells, as in the bay of Lamlash. Mr. Smith
has also traced sea-worn terraces on each side of the Clyde below
Dumbarton and between the Cloch Lighthouse and Largs.

We are indebted to Sir Philip Egerton for some new details re-
specting the shelly gravel of Cheshire, of which he had previously
treated; and to Mr. Murchison and Professor Sedgwick for a joint
j)aper on " a raised beach in Barnstaple Bay on the north-west coast
of Devonshire." This beach puts on for several miles where it is
best exposed, the form of a horizontal under terrace resting upon an
indented and irregular surface of the older formations. It presents
a cliff towards the sea, in which beds of calcareous grit, sandstone,
and shingle are seen perfectly stratified. The bottom of the de-
posit is chiefly composed of indurated shingles resting on the ledges
of the older rocks, and filling up their inequalities. Through the
whole clifF, but especially in the indurated grits, shells are abun-
dantly dispersed, identical in species with those now living on the
coast, and well preserved, though sometimes waterworn.

The authors point out that these beds cannot have been formed by
accumulations of blown sand. They demonstrate an elevation of
the coast during the modern period; and there are phacnomenaboth
on the north and south coasts of Devonshire and Cornwall, which

Mr. LyelVs Address. 399

aflford proofs of modern clianjres in the level of the land, both of
upheaval and depression. The raised beach of Hope's Nose,
correctly described by Mr. Austen, is the most striking instance
in South Devon.

The quantity of rise of land in the modern period is from ten to
forty feet in South Devon and Cornwall, nearly seventy feet in
North Devon, while in Lancashire, Cheshire, and Shropshire there
are marine deposits with recent shells at the height of from SOO to
500 feet above the sea.

It is natural to inquire what changes the surface of the dry
land in England may have undergone during the occurrence of such
upward and downward movements. Perhaps some observations
lately made by Mr. Bowerbank in the south of the Isle of Wight
may elucidate this point. He has given us an account of a bed of
chalky detritus, containing recent land shells, (at Gore Cliff. This
bed is ten feet thick, and rests immediately upon chalk marl.
Many of the shells, which are plentifully scattered through it, retain
their colour. As the deposit ranges to the foot of St. Catherine's
Down, it is possible that the waste and denudation of that chalk
hill may have supplied the materials. I have lately seen similar
detritus resting on the chalk with flints, and arranged in numerous
thin layers in the section exposed in cutting the railroad at Win-
chester, where a black layer of peaty earth and carbonized wood
intersects thin layers of white chalk rubble, from twenty to thirty
feet thick. Such appearances are, in fact, very general in chalk
districts ; a bed of flints not waterworn occurring on the highest
downs, while fragmentary chalk, often inclosing land shells, occurs
on their slopes and at lower levels. Violent rains have been known
even of late years to tear off the turfy covering from certain points
near Lewes, and to wash away flints and chalky mud, and leave
them in the hollow combs or flanks of the hills. This action of the
elements would be most powerful at periods when the chalk first
emerged from the sea, or whenever it assumed in the course of sub-
terranean disturbances a new position or physical outline.

We must, I think, infer from the occurrence of certain recent
marine shells and shingle in the bottom of what has been termed
the elephant-bed at Brighton, that the chalk in the South-east of
England has undergone some movements of a modern date, the
land having subsided there to the depth of fifty or sixty feet, and
having been subsequently raised up again to a level somewhat
higher than its original position*.

If it should appear upon careful research that the land shells found
in terrestrial alluviums covering the chalk are almost universally
of recent species, I should not conclude that the emergence of the
chalk hills from the sea had generally occurred at a very modern
period, but merely that these hills had been modified in shape in
recent times, and that during that modification alluviums of older
date had been washed away, or the land shells which they may once

* See Principles of Geology, 4th edit., vol. iv. p. 274.

400 Geological Society.

have contained have decomposed and disappeared. In regard to
the great numbers of these shells preserved throughout the bed at
Gore CHfF, and in many other places even at greater depths, it will
not seem surprising to those who have observed the number of dead
land shells vvhich are strewed over the surface of the chalk downs,
or lie concealed in the green turf in numbers almost as countless as
the blades of grass. If the slightest wash of water should pass
over such a soil, it must float off myriads of these shells, and they
would immediately be involved in that white cream-coloured mud
which descends from wasting hills of chalk after heavy rains. Land
shells so buried may retain their colour for indefinite periods, as is
shown by the state of species in the loess of the Rhine, and even in
tertiary strata of much higher antiquity.

While a variety of geological monuments are annually discovered
which attest modern alterations in the level of the land, it is im-
portant to remark that new testimony is also daily obtained of the
rising and sinking of land in our own times. I discussed at some
length, in my last Anniversary Address, the evidence for and against
the upheaval of the coast of Chili during the earthquake of 1822, a
controverted point to which our attention has lately been again re-
called. I may remark, however, that since we have ascertained the
fact of a rise of three, five, and even ten feet in parts of the same
country in 1835, so distinctly attested by Captain Fitzroy, all
doubts entertained as to the permanent effects of a preceding con-
vulsion are comparatively of small interest. Don Mariano Rivero
dissents from the opinion that a change of level occurred at Valpa-
raiso in 1822, and Colonel Walpole, after seeing the ground and
conversing with persons who were on the spot in 1822, and who
still reside there, also considers the statement of a rise to have been
inaccurate. On the other hand Mr. Caldcleugh, who was formerly
sceptical on the same point, has now come round to the opinion of
Mrs. Callcott (Maria Graham), and believes that an elevation of
land did take place.

Mr. Darwin, whose opportunities of investigation both in Chili
and other parts of South America have been so extensive, thinks
it quite certain that the land was upheaved two or three feet
during the earthquake of 1822, and he met with none of the inha-
bitants who doubted the change of level. He states that the rise
of land, even in the bay of Valparaiso, was far from being uniform,
for a part of a fort not formerly visible from a certain spot has,
subsequently to the earthquake, fallen within the line of vision.
The most unequivocal proof of a recent rise is drawn from the
acorn-shells, Balanidce, found adhering to the rock above the reach
of the highest tides. These were observed by Mr. Darwin sixty
miles south of Valparaiso, and at Quintero, a few miles to the north
of it; but his friend Mr. Alison detected them on a projecting point
of rock at Valparaiso itself. The attached shells were there seen
at the height of fourteen feet above high-water mark, and were only
exposed upon the removal of the dung of birds, by which they would
have been concealed from ordinary observation. In Mr. Darwin's

Mr. Ly eWs Address. 401

paper you will find many other facts elucidating the rise of land at
Valparaiso, and he has also treated of the general question of the
elevation of the whole coast of the Pacific from Peru to Terra del
Fuego. Beds of shells were traced by him at various heights above
the sea, some a few yards, others 500 or even 1300 feet high, the'
shells being in a more advanced state of decomposition in propor-
tion to their elevation. Mr. Darwin also shows that parallel ter-
races such as those of Coquimbo, described by Captain Basil Hall
and others, which rise to the height of 300 feet and more, are of
marine origin, being sometimes covered with sea-shells, and they
indicate successive elevations. There are also grounds for believing
that the modern upheaval of land has proceeded not only by sud-
den starts during convulsions of the earth, but also by insensible
degrees in the intervals between earthquakes, as is now admitted to
be the case in parts of Norway and Sweden. l

This gradual and insensible rising is supposed to affect, not only
the region of the Andes, but also the opposite or eastern coast of
South America, where earthquakes are never experienced : for
the Pampas of Buenos Ayres bear marks of having risen to their
present height during a comparatively modern period, while the
coast line of the Pacific, or the region of earthquakes and volcanic
eruptions, has been the theatre of more violent movements.

It is curious to reflect that if in one portion of a large area of the
earth's surface a rise of land takes place at the rate of a few inchesi
in a century, as around Stockholm, while in another portion of the
same area land is uplifted about a yard during an equal period, there
will be caused, if sufficient time be allowed, a group or chain of
lofty mountains in one place, and in the other a low country like
the Pampas of South America.

Evidence of a sinking down of land, whether sudden or gradual,
is usually more difficult to obtain than the signs of upheaval. I shall
therefore mention some facts which have been lately communicated
to me by Professor Nilsson, from* which it appears that Scania, of
the southernmost part of Sweden, has been slowly subsiding for se-
veral centuries, in the same manner as was lately shown to be the
ease with part of Greenland. In the first place there are no elevated
beds of recent marine shells in Scania, like those near Stockholm and
further to the north. Linnaeus, with a view of ascertaining whether
the waters of the Baltic were retiring from the Scanian shore,
measured in 1749 the distance between the sea and a large stone
near Trelleborg. Now Mr. Nilsson informs me that this same
stone is a hundred feet nearer the water's edge than it was in Lin-
naeus's time, or eighty-seven years before. He also states that there,
is a submerged peat moss, consisting of land and freshwater plants,
beneath the sea at a point to which no peat could have been drifted
down by any river. But, what is still more conclusive, it is found
that in sea-port towns, all along the coast of Scania, there are streets
below the high-water level of the Baltic, and in some cases below
the level of the lowest tide. Thus when the wind is high at Malmo
the water overflows one of the present streets, and some years ago

Third Series. Vol. 10. No. 62. May 1837. 3 F

402 Geological Societt/.

some excavations showed an ancient street in the same place eight
feet below, and it was then seen that there had evidently been an
artificial raising of the ground, doubtless in consequence of that sub-
sidence. There is also a street at Trelleborg and another at
Skanor a few inches below high-water mark ; and a street at Ystad
is just on a level with the sea, at which it could not have been ori-
ginally built. I trust that we shall soon receive more circumstantial
details of these curious phaenomena, which are the more interesting
because it has been shown that the elevatory movement in Sweden
diminishes in intensity as we proceed southward from the North
Cape to Stockholm, from which it seems probable that after passing
the line or axis of least movement, where the land is nearly stationary,
a movement may be continued in an opposite direction, and thus
cause the gradual sinking of Scania.

I cannot take leave of this subject without remarking that the
occurrence in various parts of Ireland, Scotland, and England, of
recent shells in stratified gravel, sand, and loam, confirm the opi-
nion which I derived from an examination of part of Sweden,
namely, that the formations usually called diluvial have not been
produced by any violent flood or debacle, or transient passage
of the sea over the land, but by a prolonged submersion of the
land, the level of which has been greatly altered at periods very
modern in our geological chronology. I now believe that by far
the greatest part of the dispersion of transported matter has been
due to the ordinary moving power of water, often assisted by ice,
and cooperating with the alternate upheaval and depression of land.
I do not mean wholly to deny that some sudden rushes of water
and partial inundations of the sea have occurred, but we are enabled
to dispense with their agency more and more in proportion as our
knowledge increases.

ORGANIC REMAINS.

Gentlemen, you have been already informed that the Council
have this year awarded two Wollaston Medals, one to Captain
Proby Cautley of the Bengal Artillery, and the other to Dr. Hugh
Falconer, Superintendent of the Botanic Garden at Sabarunpore,
for their researches in the geology of India, and more particularly
their discovery of many fossil remains of extinct quadrupeds at the
southern foot of the Himalaya mountains. At our last Anniversary
I took occasion to acknowledge a magnificent present, consisting of
duplicates of these fossils, which the Society had received from
Captain Cautley, and since that time other donations of great value
have been transmitted by him to our museum. These Indian fossil
bones belong to extinct species of herbivorous and carnivorous
mammalia, and to reptiles of the genera crocodile, gavial, emys, and
trionyx, and to several species of fish, with which shells of fresh-
water genera are associated, the whole being entombed in a for-
mation of sandstone, conglomerate, marl, and clay, in inclined stra-
tification, composing a range of hills called the SiwaHk, between
the rivers Sutledge and Ganges. Th ese hills rise to the height of

Mr. Lyell's Address, 403

from 500 to 1000 feet above the adjacent plains, some of the loftiest
peaks being 3000 feet above the level of the sea.

When Captain Cautley and Dr. Falconer first discovered these
remarkable remains their curiosity was awakened, and they felt
convinced of their great scientific value ; but they were not versed in
fossil osteology, and being stationed on the remote confines of our
Indian possessions, they were far distant from any living authorities
or books on comparative anatomy to which they could refer. The
manner in which they overcame these disadvantages, and tlie en-
thusiasm with which they continued for years to prosecute their
researches when thus isolated from the scientific world is truly ad-
mirable. Dr. Royle has permitted me to read a part of their cor-
respondence with him when they were exploring the Siwalik moun-
tains, and I can bear witness to their extraordinary energy and per-
severance. From time to time they earnestly reqiiested that Cuvier's
works on osteology might be sent out to them, and expressed their
disappointment when, from various accidents, these volumes failed
to arrive. The delay perhaps was fortunate, for being thrown en-
tirely upon their own resources, they soon found a museum of com-
parative anatomy in the surrounding plains, hills, and jungles, where
they slew the wild tigers, buffalos, antelopes, and other Indian qua-
drupeds, of which they preserved the skeletons, besides obtaining
specimens of all the genera of reptiles which inhabited that region.
They were compelled to see and think for themselves while com-
paring and discriminating the different recent and fossil bones, and
reasoning on the laws of comparative osteology, till at length they
were fully prepared to appreciate the lessons which they were
taught by the works of Cuvier. In the course of their labours they
have ascertained the existence of the elephant, mastodon, rhinoceros,
hippopotamus, ox, buffalo, elk, antelope, deer, and other herbi-
vorous genera, besides several canine and feline carnivora. On some
of these Dr. Falconer and Captain Cautley have each written sepa-
rate and independent memoirs. Captain Cautley, for example, is the
author of an article in the Journal of the Asiatic Society, in which he
shows that two of the species of mastodon described by Mr. Clift
are, in fact, one, the supposed difference in character having been
drawn from the teeth of the young and adult of the same species. I
ought to remind you that this same gentleman was the discoverer,
in 1833, of the Indian Herculaneum or buried town near Behat,
north of Seharunpore, which he found seventeen feet below the sur-
face of the country when directing the excavationofthe Doab Canal*.
But I ought more particularly to invite your attention to the
joint paper by Dr. Falconer and Captain Cautley on the Sivatherium,
a new and extraordinary species of mammalia, which they have mi-
nutely described and figured, offering at the same time many pro-
found speculations on its probable anatomical relations. The cha-
racters of this genus are drawn from a head almost complete, found

* Journ. of Asiatic Society, Nos. xxv. and xxix. 1834. Principles of
Geology, 4th and subsequent editions. See Index, Behat.

3F2

.404« Geological Society,

at first enveloped in a mass of hard stone, which had Iain as a
boulder in a water-course, but after much labour the covering of
stone was successfully removed, and the huge head now stands out
with its two horns in relief, the nasal bones being projected in a
free arch, and the molars on both sides of the jaw being singularly
perfect. This individual must have approached the elephant in size.
The genus Sivatherium, say the authors, is the more interesting, as
helping to fill up the important blank which has always intervened
between the ruminant and pachydermatous quadrupeds ; for it com-
bines the teeth and horns of a ruminant, with the lip, face, and
probably proboscis of a pachyderm. They also observe, that the
extinct mammiferous genera of Cuvier were all confined to the Pa-
chydermata, and no remarkable deviation from existing types had
been noticed by him among fossil ruminants, whereas the sivathe-
rium holds a perfectly isolated position, like the giraffe and the
camels, being widely remote from any other type.

1 have not space to enter upon the warm discussion which has
arisen in France between MM. Blainville and GeofFroy St. Hilaire
respecting the amount of analogy which exists between the Siva-
therium and the Giraffe ; but I observe with pleasure that in the
course of that controversy those distinguished naturalists do justice
to the zeal and talents displayed by our countrymen Captain Caut-
ley and Dr. Falconer, and to the services which they have rendered
to science.*

While these discoveries were made on the banks of the tributaries
of the Indus and the Ganges, Mr. Darwin was employed in col-
lecting the bones of large extinct mammalia, near the banks of the
Rio Plata, in the Pampas of Buenos Ayres and in Patagonia. Mr.
Owen has enabled me to announce to you in a few words some of
the most striking results which he has obtained from his exami-
nation of the specimens liberally presented by Mr. Darwin to the
College of Surgeons, and of which casts will soon be made for our
own and other public museums. In the first place, besides a cra-
nium with teeth of the Megatherium, Mr. Darwin has brought
home portions of another animal as large as an ox, and allied to the
Megatherium. Fragments of its armour are preserved, as well as
its jaws, femur, and other bones. There is also a third creature of
the order Edentata, and belonging to this same family of Dasypo-
didae, in the shape of a gigantic Armadillo, as large as a Tapir. Of
the ruminant order there is also a no less remarkable representative
in the remains of a gigantic Llama from the plains of Patagonia,
which must have been as large as a camel and with a longer neck :
and lastly, of the Rodentia there is the cranium of a huge animal of
the size of a rhinoceros, with some modification in the form of the
skull resembling that in the Wombat.

These fossils, of which a description will shortly be given to the
Society by Messrs. Clift and Owen, establish the fact that the pe-
culiar type of organization which is now characteristic of the South
American mammalia has been developed on that continent for a

* L. and E. Phil. Mag. vol. ix. p. 193, etseq.

Mr. LyelPs Address. 405

long period, sufficient at least to allow of tlie extinction of many
large species of quadrupeds. The family of the armadillos is now
exclusively confined to South America and here we have from the
same country the Megatherium, and two other gigantic represen-
tatives of the same family. So in the Camelidse, South America is
the sole province where the genus Auchenia or Llama occurs in a
living state, and now a much larger extinct species of Llama is dis-
covered. Lastly, among the rodents, the largest in stature now
living is the Capybara, which frequents the rivers and swamps of
South America and is of the size of a hog. Mr. Darwin now
brings home from the same continent the bones of a fossil rodent
not inferior in dimensions to the rhinoceros.

These facts elucidate a general law previously deduced from the
relations ascertained to exist between the recent and extinct qua-
drupeds of Australia ; for you are aware that to the westward of
Sydney on the Macquarie River, the bones of a large fossil kan-
garoo and other lost marsupial species have been met with in the
ossiferous breccias of caves and fissures.

A cavern has lately been examined at Yealm Bridge, six miles
south-east from Plymouth, by one of our members, Lieut. Col.
Mudge, R.E., from whose account it appears that the bones of hy-
senas are very numerous there. They are associated with those of
the elephant, rhinoceros, horse, and other animals usually found in
caves. The number of fossil Carnivora, such as the hyaena, wolf, fox,
and bear, which have now been met with in districts of cavernous
limestone in Great Britain, is so great that we are the more struck
with the rarity and general absence of such remains in surrounding
and intervening districts, over which the same beasts of prey must
have ranged. The Pachydermata, as the elephant, rhinoceros, and
hippopotamus, are often discovered in ancient alluvial or fluviatile
deposits ; but had there been no caves and fissures we should
scarcely have obtained any information respecting the existence of
lions, tigers, hyaenas, and other beasts of prey which inhabited the
country at the same period.

The remains of at least two distinct Saurian animals have been
discovered by Dr. Riley and Mr. Samuel Stutchbury, in the dolo-
mitic conglomerate of Durdham Down near Bristol. They are
allied to the Iguana and Monitor, but the teeth, vertebrae, and other
bones exhibit characters by which they are seen to be generically
distinct from all existing reptiles. They are particularly deserving
of your attention as occurring in the bottom of the magnesian lime-
stone formation, the oldest strata in which the bones of reptiles have
as yet been found in Great Britain. The most ancient examples
of fossil reptiles known on the continent of Europe occur also in
the zechstein of Germany, a formation of about the same age.

I alluded last year to a memoir of Sir Philip Egerton's, in which
he pointed out some peculiarities in the structure of the cervical
vertebrae of the Ichthyosaurus. He has now proved that in all the
species of this genus there are three accessory bones, which he pro-
poses to call, from their shape and position, sub vertebral wedge

406^ Geological Society,

bones. They are supplementary to the atlas, axis, and third ver-
tebra of the neck, and seem to have escaped the observation of
Cuvier and other osteologists.

Mr. Lewis Hunton has communicated to the Society an elaborate
account of a section of the upper lias and marlstone in Yorkshire,
showing that different beds in those formations are characterized
by particular species of Ammonites and other Testacea, each species
having a limited vertical range. His observations are valuable not
only as illustrating the distribution of fossils on the coast near
Whitby, but also as furnishing a point of comparison between that
district and many others in Great Britain. Mr. W. C. Williamson
of Manchester has had the same object in view in studying the fos-
sils of the oolitic formations of the coast of Yorkshire, and informs
us, as the result of his patient investigation, that although certain as-
semblages of fossils abound in particular subdivisions of the oolite,
many species range from the lowermost to nearly the highest beds.
This inference is confirmed when we compare the lists drawn up
by Mr. Williamson, and those published by Professor Phillips and
other competent authorities. Thus some of the shells of the in-
ferior oolite, mentioned in Mr. Williamson's list {Trigonia gibbosa,
for example), occur also in the Portland-stone of Wiltshire ; another,
as Ostrea Marshii, is characteristic of the cornbrash in the same
county ; others pass downwards to the lias, as Orbicula reflexa and
Ammonites striatulus. If you consult the tables of organic remains
which Dr. Fitton has annexed to his excellent monograph on the
strata below the chalk, just published in our Transactions, (2nd Se-
ries, vol. iv. part 2.) you will see that a considerable number of
shells pass from the upper oolitic groups into the green-sand. We
are not to conclude from these facts that certain sets of fossils may
not serve as good chronological tests of geological periods, but we
must b^ cautious not to attach too much importance to particular
species, some of which may have a wider, others a more limited
vertical range. The phaenomena alluded to are strictly analogous
to those with which we are familiar in the more modern deposits,
where different tertiary formations contain some peculiar Testacea,
together with others common to older or newer groups, or where
shells of species now living in the sea are associated with others that
are extinct.

An assemblage of fossil shells has been presented to our museum
by Mr. J. Leigh and Mr. J. W. Binney, found at Collyhurst near
Manchester, in red and variegated marls, which were referred by
them at first to the upper division of the new red sandstone group;
but Professors Sedgwick and Phillips consider them to be a red and
variegated deposit, belonging to the magnesian limestone series.
As these fossils are new and characteristic of a particular subdivi-
sion of the beds between the lias and coal, it is to be hoped that
they will soon be described and figured.

The petrifaction of wood, and more especially its silicification,
still continues to present obscure problems to the botanist and

Mr. LyelFs Address, ^07

chemist. The first step towards their solution will probably be
made by carefully examining vegetables in different stages of petri-
faction ; and with this view Mr. Stokes has procured several speci-
mens of wood, partly mineralized and partly not. Among these is
a piece found in an ancient Roman aqueduct in Westphalia, in
which some portions are converted into spindle-shaped bodies
consisting of carbonate of lime : while the rest of the wood
remains in a comparatively unchanged state. The same author
has pointed out cases both of siliceous and calcareous fossils
where the lapidifying process must have commenced at a num-
ber of separate points, so as to produce spherical or fusiform pe-
trifactions, independent of each other, in which the woody struc-
ture is apparent, while in the intervening spaces the wood has de-
cayed, having after removal been replaced by mineral matter. In
some petrifactions the most perishable, in others the most durable
portions of plants are preserved, variations which doubtless depend
on the time when the mineral matter was supplied. If introduced
immediately on the first commencement of decomposition, then the
most destructible parts are lapidified, while the more durable do
not waste away till afterwards, when the supply has failed, and so
never become petrified. The converse of these circumstances gives
rise to exactly opposite results. As to the manner in which the
minutest pores and fibres discoverable by the microscope, even the
spiral vessels themselves can be turned into stone, or have their
forms faithfully represented by inorganic matter, no satisfactory
explanation has ever yet been offered. In considering, however, this
question, you will do well to consult the important suggestion which
a celebrated chemist, our late lamented Secretary, Dr. Turner, has
thrown out on the application of chemistry to geology. He reminds
us that whenever the decomposition of an organic body has begun,
the elements into which it is resolved are set free in a state peculiarly
adapting them to enter into new chemical combinations. They are
in what is technically termed a nascent state, the constituent mole-
cules being probably of extreme smallness and in a fluid or gaseous
form, ready to obey the slightest impulse of chemical affinity, so
that if the water percolating a stratum be charged with mineral in-
gredients, and come in contact with elements thus newly set free, a
mutual action takes place, and new combinations result, in the course
of which solid particles are precipitated so as to occupy the place
left vacant by the decomposed organic matter. In a word, all the
phaenoraena attendant on slow putrefaction must be studied when-
ever we attempt to reason on the conversion of fossil bodies into
stone; and in regard to silicification, Dr. Turner has shown how
great a quantity of silex is set free as often as felspar decomposes,
and how abundantly siliceous matter may be imparted from this
source alone to running water throughout the globe.

As I have mentioned the name of Dr. Turner, I cannot pass on
without an expression of sorrow for the untimely death of that
amiable and distinguished philosopher. Mr, \V he well and Mr.
Murchison alluded in most feeling terms this morning at the Ge-

408 Geological Society.

neral Meeting to this melancholy event, which is too recent and too
painful to myself and others to allow me now to dwell longer upon it.

Before quitting the subject of vegetable petrifactions, I ought
to mention a memoir just published, by Mr. H. R. Goppert,
Professor of Botany at Breslau, ** On the various Conditions in
which Fossil Plants are found, and on the Process of Lapidifica-
tion*." He has instituted a series of most curious experiments,
and his success in producing imitations of fossil petrifactions has
been very remarkable. I have only space to allude to one or two
examples. He placed recent ferns between soft layers of clay,
dried these in the shade, and then slowly and gradually heated
them, till they were red hot. The result was the production of so
perfect a counterpart of fossil plants as might have deceived an ex-,
perienced geologist. According to the different degrees of heat
applied, the plants were obtained in a brown or perfectly carbon-
ized condition, and sometimes, but more rarely, they were in a black
shining state, adhering closely to the layer of clay. If the red heat
was sustained until all the organic matter was burnt up, only an im-
pression of the plant remained.

The same chemist steeped plants in a moderately strong solution
of sulphate of iron, and left them immersed in it for several days
until they were thoroughly soaked in the liquid. They were then
dried and kept heated until they would no longer shrink in volume,
and until every trace of organic matter had disappeared. On cool-
ing them he found that the oxyd formed by this process had taken
the form of the plants. Professor Goppert then took fine vertical
slices of the Scotch fir, Pinus sylvestris, and treated them in the
same way ; and so well were they preserved, that, after heating, the
dotted vessels so peculiar to this family of plants were distinctly vi-
sible. A variety of other experiments were made by steeping
animal and vegetable substances in siliceous, calcareous, and me-
tallic solutions, and all tended to prove that the mineralization of
organic bodies can- be carried much further in a short time than
had been previously supposed.

These experiments seem to open a new field of inquiry, and will,
I trust, soon be repeated in this country. In endeavouring, how-
ever, to verify them, the greatest caution will be required, or we
may easily be deceived. We must ascertain, for example, with
certainty that every particle of animal or vegetable matter is driven
off before we attempt to determine the full extent to which minerali-
zation may have proceeded. Professor Goppert is doubtless aware
that coniferous wood may be burnt and reduced to charcoal, and
after havnig been kept for some time at a red heat, will continue to
exhibit, on being cooled, the discs or reticulated structure to which
he alludes. If, therefore, some small particles of carbon remain in the
midst of the oxide of iron, such portionsmayretain traces of the ves-
sels peculiar to coniferous wood ; and an observer not on his guard,

* Poggendorff, Annalen der Physik und Chemie, vol. xxxviii. part 4.
Leipsic, 1836.

Mr. Lyell's Address, 409

might infer that the same structure was preserved throughout the
mass.

In my last address, I alluded to Mr. Lonsdale's detection of vast
numbers of microscopic corallines and minute shells in the substance
of the white chalk of various counties in England, where this rock
had not been suspected of consisting of recognisable organic bodies.
I cannot deny myself the pleasure of mentioning the still more sin-
gular and unexpected facts brought to light during the last year, by
Professor Ehrenberg of Berlin, respecting the origin of tripoli. I
need scarcely remind you, that tripoli is a rock of homogeneous
appearance, very fragile and usually fissile, almost entirely formed
of flint, and which was called polir-schiefer, or polishing slate, by
Werner, being used in the arts for polishing stones or metals.
There have been many speculations in regard to its origin, but it
was a favourite theory of some geologists that it was a siliceous
shale hardened by heat. The celebrated tripoli of Bilin in Bohe-
mia consists of siliceous grains united together without any visible
cement, and is so abundant that one stratum is no less than fourteen
feet thick. After a minute examination of this as well as of the tri-
poli from Planitz in Saxony, and another variety from Santa Fiora
in Tuscany, and one from the Isle of France, Ehrenberg found that
the stone is wholly made up of millions of siliceous cases and skele-
tons of microscopic animalcules. It is probably known to you, that
this distinguished physiologist has devoted many years to the ana-
tomical investigation of the infusoria, and has discovered that
their internal structure is often very complicated, that they have a
distinct muscular and nervous system, intestines, sexual organs
of reproduction, and that some of them are provided with sili-
ceous shells, or cases of pure silex. The forms of these dura-
ble shells are very marked and various, but constant in particular
genera and species. They are almost inconceivably minute, yet
they can be clearly discerned by the aid of a powerful microscope,
and the fossil species preserved in tripoli are seen to exhibit in the
family Bacillaria and some others the same divisions and transverse
lines which characterize the shells of living infusoria.

In the Bohemian schist of Bilin, and in that of Planitz in Saxony,
both of them tertiary deposits, the species are freshwater, and are
all extinct. The tripoli of Cassel appears to be more modern, and
the infusoria in that place, which are also freshwater, are some of
them distinctly identical with living species, and others not. In the
tripoli brought from the Isle of France, the cases or shells all be-
long to well-known recent marine species.

The flinty shells of which we are speaking although hard are
very fragile, breaking like glass, are therefore admirably adapted
when rubbed for wearing down into a fine powder fit for polish-
ing the surface of metals. It is difficult to convey an idea of
their extreme minuteness, but I may state that Ehrenberg esti-
mates that in the Bilin tripoli there are 41,000 millions of indivi-
duals of the Gaillonella distans in every cubic inch of stone. At

Third Series. Vol. 10. No. 62. May 1837. 3 G

410 Geological Society.

every Stroke therefore of the polishing ?tone we crush to pieces se-
veral thousands if not myriads of perfect fossils.

Gentlemen, — Although I have already extended this Address be-
yond the usual limits, I cannot conclude without congratulating you
on the appearance of Dr. Buckland's Bridgewater Treatise, a work
in the execution of which the author has most skilfully combined
several distinct objects. He has briefly explained the manner in
which the materials of the earth's crust are arranged, and the evi-
dence which that arrangement affords of contrivance, wisdom, and
foresight. He has also given us a general view of the principal facts
brought to light by the study of organic remains ; thus contributing
towards the filling up one of the greatest blanks which existed in
the literature of our science, while at the same time he has pointed
out the bearing of these phaenomena on natural theology.

He has shown that geology affords one kind of testimony perfectly
distinct from natural history of the adaptation of particular means
and forces to the accomplishment of certain ends for which the habit-
able globe has been framed. " These proofs are illustrated in the
author's chapters on the origin and mechanism of springs, on the
distribution of metallic and other minerals in the earth, and the
position of coal in stratified rocks. In reference to these points it
is demonstrated that some even of the most irregular forces have
produced highly beneficial results, in modifying the subterranean
economy of the globe. But I shall not dwell on this part of the
Treatise, but pass on at once to that which constitutes the body of
the work, and which relates to palaeontology.

In considering this department, the number and variety of objects
which offer themselves to the naturalist are so great, that the choice
was truly embarrassing. Dr. Buckland has judiciously selected a
few of the most striking examples from each of the great classes of
organic remains, and when speaking of extinct animals, has ex-
plained the method by which the anatomist and physiologist have
been able to restore the organization of the entire individual, by
reasoning from the evidence afforded by a few bones or other relics
preserved in a fossil state. He has described the parts of the
living animal or plant most nearly analogous to those which are
found buried in the earth, usually illustrating by figures the di-
stinctness and at the same time the resemblance of the recent and
extinct species, showing that all are parts of one great scheme, and
that the lost species even supply links which are wanting in the
existing chain of animal and vegetable creation.

It is impossible to read the account given of the Megatherium,
and to contrast it with that drawn up by Cuvier of the same species,
without being struck with the increased interest and instruction, and
the vast accession of power derived from viewing the whole mecha-
nism of the skeleton in constant relation to the final causes for
which the different organs were contrived.

The chapter on saurian and other reptiles has afforded the Pro-
fessor another beautiful field for exemplifying the infinite variety of

Mr. Lyell's Address. 4H

mechanical contrivances and combinations of form and structure
which the fossil representatives of that class exhibit.

The account also of the Cephalopodous Mollusca, so many thou-
sands of which are scattered through the strata, and which until
very recently have presented so obscure a problem to the naturalist,
is full of original observation. The history of the animals which
formed the Belemnites, of which it appears that nearly one hun-
dred species are now known, and the proofs adduced that they
were provided with ink-bags like the cuttle-fish, the description
also of the fossil pen-and-ink fish, or Loligo, and other sections of
this part of the Treatise, carry our information respecting the fnmily
of naked Cephalopods much further than was ever attempted in any
previous work. Nor should I omit to mention the exposition of an
ingenious theory for the use of the siphuncle and air-chambers of
the Ammonite, which, whether confirmed by future examination or
not, becomes in the author's hands the means of conveying to the
reader a clear and well-defined notion of the varied forms and
complicated structure of these shells, and of awakening a lively de-
sire to understand their singular organization.

I may also recall to your notice the just and striking manner in
which certain physical inferences are drawn from the conformation
of the eyes of extinct Crustacea, such as the Trilobite. The most
delicate parts of these organs are sometimes found petrified in
rocks of high antiquity, and it is justly observed, that such opti-
cal instruments give information regarding the condition of the
ancient sea and ancient atmosphere, and the relations of both these
media to light. The fluid in which these marine animals lived at
remote periods must have been pure and transparent to allow the
passage of light to organs of vision resembling those of living Cru-
staceans ; and this train of reasoning naturally leads us still further,
and to more important consequences, when we reflect on the general
adoption of the undulatory theory of light, and the connexion be-
tween light, heat, electricity, and magnetism.

I have heard it objected, that the zoologist and botanist had
already advanced such abundant proofs of design in the construc-
tion of living animals, and plants, that the auxiliary evidence of
palaeontology was useless, and that to appeal to fossils in support of
the same views was to add weaker to stronger arguments. In
the living animal, it is said, we can study its entire organization,
observe its habits, see the manner in which it applies each organ,
and so verify with certainty the ends for which any particular mem-
ber was formed and fashioned. But in the case of the fossil, we
have first to infer the greater part of the organization from such
parts as alone remain, and then further to infer from analogy the
habits and functions discharged, and lastly the former conditions of
existence of the creatures so restored. If then we occasionally fail
into error when speculating on the use of the organs of living spe-
cies, how much more easily may we be deceived in regard to the
fossil !

In answering this objection, it cannot be denied that the data
;3 G 2

4*12 Geological Society.

supplied by palaeontology are less complete; but they are never-
theless abundantly sufficient to establish a very close analogy be-
tween extinct and recent species, so as to leave no doubt on the
mind that the same harmony of parts and beauty of contrivance
which we admire in the living creature has equally characterized
the organic world at remote periods. If this be granted, it is
enough ; the geologist can then bring new and original arguments
from fossil remains to bear on that part of natural theology which
seeks to extend and exalt our conceptions of the intelligence,
power, wisdom, and unity of design manifested in the creation.

It can now be shown that the configuration of the earth's surface
has been remodelled again and again ; mountain chains have been
raised or sunk, valleys have been formed, again filled up, and
then re-excavated, sea and land have changed places, yet through-
out all these revolutions, and the consequent alterations of local and
general climate, animal and vegetable life has been sustained. This
appears to have been accomplished without violation of those laws
now governing the organic creation, by which limits are assigned to
the variability of species. There are no grounds for assuming that
species had greater powers of accommodating themselves to new
circumstances in ancient periods than now. The succession of
living beings was continued by the introduction into the earth from
time to time of new plants and animals. That each assemblage of
new species was admirably adapted for successive states of the
globe, may be confidently inferred from the fact of the myriads of
fossil remains preserved in strata of all ages. Had it been other-
wise, had they been less fitted for each new condition of things as
it arose, they would not have increased and multiplied and endured
for indefinite periods of time.

Astronomy had been unable to establish the plurality of habitable
worlds throughout space, however favourite a subject of conjecture
and speculation ; but geology, although it cannot prove that other
planets are peopled with appropriate races of living beings, has
demonstrated the truth of conclusions scarcely less wonderful, the
existence on our own planet of many habitable surfaces, or worlds
as they have been called, each distinct in time, and peopled with its
peculiar races of aquatic and terrestrial beings.

Thus as we increase our knowledge of the inexhaustible variety
displayed in living nature, and admire the infinite wisdom and
power which it displays, our admiration is multiplied by the reflec-
tion that it is only the last of a great series of pre-existing crea-
tions of which we cannot estimate the number or limit in past
time.

All geologists will agree with Dr. Buckland, that the most per-
fect iSnity of plan can be traced in the fossil world throughout all
the modifications which it has undergone, and that we can carry back
our researches distinctly to times antecedent to the existence of
man. We can prove that man had a beginning, and that all the
species now contemporary with man, and many others which pre-
ceded, had also a beginning ; consequently the present state of the

Mr. Lyell's Address, 413

organic world has not gone on from all eternity as some philoso-
phers had maintained.

But when conceding the truth of these propositions, I am pre-
pared to contest another doctrine which the Professor advocates,
namely, tiiat by the aid of geological monuments we can trace back
the history of our terraqueous system to times anterior to the first
creation of organic beings. If it was reasonable that Hutton should
in his time call in question the validity of such a doctrine, whether
founded on the absence of organic remains in strata called primary
or in granite, still more are we bound, after the numerous facts
brought to light by modern geology, to regard the opinion as more
than questionable. I observe with pleasure that Dr. Buckland
broadly assumes what I have elsewhere termed the metamorphic
theory, having stated in his 6th chapter that beds of mud, sand, and
gravel, deposited at the bottom of ancient seas,^ have been converted
by heat and other subterranean causes into gneiss, mica slate, horn-
blende slate, clay slate, and other crystalline schists. But if this
transmutation be assumed, it must also be admitted that the oblite-
ration of the organic remains, if present, would naturally have ac-
companied so entire a change in mineral structure. The absence,
then, of organic fossils in crystalline stratified rocks, of whatever
age, aftbrds no presumption in favour of the non-existence of ani-
mals and plants at remote periods.

The author, however, in another part of his Treatise contends,
that even if the strata called primary once contained organic re-
mains, there is still evidence in the fundamental granite of an ante-
cedent universal state of fusion, and consequently a period when
the existence of the organic world, such as it is known to us, was im-
possible. There was, he says, one universal mass of incandescent
elements, forming the entire substance of the primaeval globe,
wholly incompatible with any condition of life which can be shown to
have ever existed on the earth*. Believing as I do in the igneous
origin of granite, I would still ask, what proof have we in the earth's
crust of a state of total and simultaneous liquefaction either of the
granitic or other rocks, commonly called plutonic ? All our evi-
dence, on the contrary, tends to show that the formation of granite,
like the deposition of the stratified rocks, has been successive, and
that different portions of granite have been in a melted state at di-
stinct and often distant periods. One mass was solid, and had been
fractured before another body of granitic matter was injected into
it, or through it in the form of veins. In short, the universal
fluidity of the crystalline foundations of the earth's crust can only
be understood in the same sense as the universality of the ancient
ocean. All the land has been under water, but not all at one
time ; so all the subterranean unstratified rocks to which man can
obtain access have been melted, but not simultaneously.

Nor can we affirm that the oldest of the unstratified rocks

* Buckland's Bridgewater Treatise, vol, i. p. 55.

414 Prof. Wheatstone on I he Thermo-electric Spark, ^c.

hitherto discovered is more ancient than the oldest stratified
formations known to us ; we cannot even decide the relations in
p 'int of age of the most ancient granite to the oldest fossUiferous
beds.

But why, I may ask, should man, to whom the early history of his
own species and the rise of nations presents so obscure a problem,
feel disappointed if he fail to trace back the animate world to its
first origin? Already has the beginning of things receded before
our researches to times immeasurably distant. Why then, atter
wandering back in imagination through a boundless lapse of years,
should we expect to find any resting-place for our thoughts, or
hope to assign a limit to the periods of past time throughout which
it has pleased an omnipotent and eternal Being to manifest his
creative power ?

But it is not my intention to advert now to these and other
points on which I happen to differ from Dr. Buckland. I would
rather express the gratification I feel in finding myself in perfect
accordance with him on so many subjects. His work is admirably
adapted to convey instruction on organic remains, and other de-
partments of geology, both to beginners and to those well versed in
the science, and is characterized throughout by a truly philosophi-
cal spirit, which betrays no desire to adhere tenaciously to dogmas
impugned or refuted by the modern progress of science. On the
contrary, the author has abandoned several opinions which he him-
self had formerly advocated; and although still attached to the
theory which teaches the turbulent condition of the planet when the
lias and other fossiliferous rocks were formed, and the general in-
sufficiency of existing causes to explain the changes which have
occurred on the earth, he yet refers in almost all parts of his book
to the ordinary operations of nature to explain a variety of phaeno-
niena once supposed to be the result of causes different in kind and
degree from those now acting.

I have now, Gentlemen, only to offer you my acknowledgements
for the high honour conferred upon me by my election to fill the
President's chair for the last two years ; and it is a source of great
satisfaction to me to feel assured of the continued prosperity an'd
usefulness of the association when 1 resign my trust into the hands
of a successor so distinguished for his zeal, talents, and varied ac-
quirements as Mr. Whewell.

LXXVIII. On the Thermo-electric Spark, <^c. Communi-
cated by C. Wheatstone, ^5<7., F.R,S., Professor of Experi-
mental Philosophy in King^s College, London,

T^HE following notice of some recent experiments made in

-■- Italy, on the production of the thermo-electric spark, and

on the chemical effects of the thermo-electric currents, will,

no doubt be acceptable to many of your readers. I shall

Prof. Wheatstone on the TTiermo-electric Sparky S^c. 415

confine myself to a simple statement and corroboration of the
facts, avoiding all theoretical considerations.

The Cav. Antinori, Director of the Museum at Florence,
having heard that Prof. Linari, of the University of Siena,
had succeeded in obtaining the electric spark from the torpedo
by means of an electro-dynamic helix and a temporary magnet,
conceived that a spark might be obtained by applying the
same means to the thermo-electric pile. Appealing to experi-
ment his anticipations were fully realized. No account of the
original investigations of Antinori has yet reached this country,
but Prof. Linari, to whom he early communicated the results
he had obtained, immediately repeated them, and published
the following additional observations of his own in Llndica-
tore Sanese, No. 50, of Dec. 13, 1 836. ^

" 1. With an apparatus consisting of temporary magnets and
electro-dynamic spirals, the wire of which was 505 feet in
length, he obtained a brilliant spark from a thermo-electric
pile of Nobili's construction consisting only of 25 elements,
which was also observed in open daylight.

" 2. With a wire 8 feet long coiled into a simple helix, the
spark constantly appeared in the dark, on breaking contact,
at every interruption of the current; with a wire 15 inches
long he saw it seldom, but distinctly ; and with a double pilej
even when the wire was only 8 inches long. In all the above-
mentioned cases the spark was observed only on breaking
contact, however much the length of the wire was dimi-
nished.

" 3. The pile consisting merely of these few elements, and
within such restricted limits of temperature as those of ice
and boiling water, readily decomposed water. Short wires
were employed having oxidizable extremities ; the hydrogen
was sensibly evolved at one of the poles.

" 4?. A mixture of marine salt moistened with water and of
nitrate of silver being placed between two small horizontal
plates of gold, communicating respectively with the wires of
the pile, the latter after having acted on the mixture gave evi-
dent signs of the appearance of revivified silver on the plate
which was next the antimony.

"5. An unmagnetic needle placed within a close helix formed
by the wire of the circuit became well magnetized by the cur-
rent.

" 6. Under the action of the same current the phaenomenon
of the palpitation of mercury was distinctly observed. "

The interesting nature of these experiments induced me to
attempt to verify the principal result. The thermo-electric
pile I employed consisted of 33 elements of bismuth and an-

416 Prof. Wheatstone o?i the Thermo-electric Spark, SfC.

timony formed into a cylindrical bundle | of an inch in dia-
meter and Ij inch in length; the poles of this pile were con-
nected by means of two thick wires with a spiral of copper
ribbon 50 feet in length and 1^ inch broad, the coils being
well insulated by brown paper and silk. One face of the pile
was heated by means of a red-hot iron brought within a short
distance of it, and the other face was kept cool by contact
with ice. Two stout wires formed the communication be-
tween the poles of the pile and the spiral, and the contact
was broken, when required, in a mercury cup between one
extremity of the spiral and one of these wires. Whenever
contact was thus broken a small but distinct spark was seen,
which was visible even in daylight. Professors Daniell, Henry,
and Bache assisted in the experiment, and were all equally
satisfied of the reality of the appearance.

At another trial the spark was obtained from the same
spiral connected with a small pile of 50 elements, on which
occasion Dr. Faraday and Prof. Johnston were present, and
verified the fact. On connecting two such piles together so
that the similar poles of each were connected with the same
wires, the same was seen still brighter*.

I conclude, therefore, that the experiment of Antinori is a
real addition to our knowledge of electrical phasnomena, and
though it was far from being unexpected, it supplies a link
that was wanting in the chain of the experimental evidence
which tends to prove that electricity, from sources however
varied, is similar in its nature and effects, a conclusion ren-
dered more than probable by the recent discoveries of Fara-
day. The effects thus obtained from the electric current ori-
ginating in the thermo-electric pile may no doubt be easily
exalted by those who have the requisite apparatus at their
disposal. It is not too much to expect, seeing the effects pro-
duced by a pile of such small dimensions, that by proper com-
binations the effects may be exalted to equal those of an ordi-
nary voltaic pile.

1 shall close this hasty communication with a notice of some
experiments on the chemical action of the thermo-electric pile
made earlier by Prof. G. D. Botto, of the University of Turin.
The form of the pile he employed may suggest some useful
hints to those who are inclined to continue the inquiry, as it
admits of the application of much higher degrees of heat than
one of the ordinary construction does, though the difference of
the thermo-electric relations of the two metals employed is not

• The two piles here employed were made by Mr. Newman of Regent-
street.

Intelligence and Miscellaneous Articles, 4-17

so considerable. Prof. Botto's experiments were published in
the Bibliolheque Universelle for September 1832, and I am not
aware that they have yet been published in any English Jour-
nal. The thermo-electric apparatus was a metallic wire, or
chain, consisting of 120 pieces of platinum wire, each one inch
in length and y^^^^ ^^ ^^ ^"^^ ^" diameter, alternating with
the same number of pieces of soft iron wire of the same di-
mensions. This wire was coiled as a helix round a wooden
rule 18 inches long, in such a manner that the joints were
placed alternately at each side of the rule, being removed from
the wood at one side to the distance of four lines. Employing
a spirit-lamp of the same length as the helix, and one of
Nobili's galvanometers, a very energetic current was shown to
exist; acidulated water was decomposed,^ and the decom-
position was much more abundant when copper instead of
platinum poles were used : in this case hydrogen only was li-
berated. The current and decomposition were augmented when
the joints were heated more highly. Better effects were ob-
tained with a pile of bismuth and antimony, consisting of 140
elements bound together into a parallelopiped, having for its
base a square of two inches, three lines, and an inch in height.
King's College, April 24, 1837.

LXXIX. Intelligence and Miscellaneous Articles,

ETHEREAL OIL OF WINE. LIEBIG AND PELOUSE.

IT is well known that a mixture of alcohol and water in the same
proportions as they exist in wine has scarcely any odour, whilst a
few drops of wine remaining in a bottle will be easily recognised by
its smell. This characteristic odour, which is possessed by all wines
in a greater or less degree, is produced by a peculiar substance,
which has all the characters of an essential oil. This substance is
not to be confounded with the aroma of wine; for it is not volatile,
and appears to be different in various kinds of wine, and in the
greater number it does not exist at all.

When large quantities of wine are submitted to distillation, an
oily substance is obtained towards the end of the operation j it is
also procured from wine lees, and especially from that which is de-
posited in the casks after fermentation has commenced.

This sethereal oil forms about one 40,000dth part of wine. In its
original state it has a strong flavour, is usually colourless, but owing
to the presence of a small portion of oxide of copper it is sometimes
greenish : when this is separated by hydrosulphuric acid it is co-
lourless. The mode of purifying this substance will be mentioned
after its composition and principal properties have been described.

This aethercal oil of wine contains a considerable quantity of oxy-
Third Series. Vol. 10. No. 62. May 1837. 3 H

418 Intelligence and Miscellaneous Articles.

gen J but its constitution is very different from that of the oxyge-
nated essential oils hitherto known. It consists of a new peculiar
acid, analogous to the fatty acids, combined with aether ; and it of
course is one of the class of compound aethers. It is the first in-
stance of the occurrence of an aether which is insoluble in water,
and produced during the vinous fermentation without the interven-
tion of the chemist. The strong resemblance which this substance
bears to the essential oils, ought to cause them to be studied under
the same point of view, and it is probable that light may be thrown
thereby upon this class of organic compounds. To the new acid
MM. Liebig and Pelouse have given the name of cenanthic acid,
and to the essential oil cenanthic (Ether.

(ENANTHIC ^THER.

The rough aether contains variable quantities of free acid : as it
is more volatile than the acid, it may be obtained free from it by
distillation by separating the first fourth of the product. In order
to obtain it perfectly pure, it is preferable to shake it frequently
with a hot solution of carbonate of soda, which dissolves the free
acid without altering the aether. The mixture is milky, and
does not become clear by long standing ; but if it be boiled for
a short time, then the aether floats on the surface of the fluid,
and may be easily separated. By agitating it with fragments
of chloride of calcium, the small quantity of water or alcohol which
it contains is easily separated. The aether thus purified is very fluid,
resembling the essential oil of mustard; it is colourless, has an ex-
tremely strong smell of wine, and which is almost intoxicating
when breathed. Its taste is strong and disagreeable. It dis-
solves readily in aether and in alcohol, even when the latter is weak;
it is not sensibly soluble in water. Its density is 0*862, that of its
vapour is 10508 ; it is not very volatile ; when distilled with water
only, about 100 grains come over with a pound of water. It boils
at about 442° Fahr.

It appears to be composed of

Six equivalents of Hydrogen . . 6

Six equivalents of Carbon 36

One equivalent of Oxygen 8

— 50

CEnanthic aether is instantaneously decomposed by the caustic
alkalis ; but the carbonates produce no sensible effect upon it ; it is
not altered by ammonia, either in solution or in its gaseous state, or
even when gently heated.

When it is boiled with caustic potash it disappears in a ^e:7i se-
conds, and if the operation be conducted in a retort, a considerable
quantity of alcohol is obtained, and there remains a very soluble
compound of cenanthic acid and potash. If this compound be de-
composed by dilute sulphuric acid, the cenanthic acid immediately
separates and forms an oily inodorous stratum on the surface of the
liquid.

Intelligence and Miscellaneous Articles. 4? 19

PREPARATION OF BORON. BY DR. R. D. THOMSON.

" In the process for obtaining boron by the action of potassium
on boracic acid, a considerable loss has been generally experienced
in consequence of an explosion which usually accompanies the
combination. A more oeconomical method has therefore been pro-
posed, viz. to decompose an alkaline fluoborate by potassium. It
appears to me that there can be only two causes which can produce
the explosion in the first mode of preparation — either the presence
of water in the boracic acid (as suggested by Dr. Thomson of Glas-
gow), or the existence of this fluid either in the potassium itself, or
in connexion with the same metal. I believe [says Dr.R. D. T.]
the latter circumstance to be the cause of the failure of the
experiment in most cases. I have succeeded [he continues] in
forming pure boron readily by the following plan; — A portion
of Tuscan boracic acid was fused in a red heat in a plati-
num crucible till it became perfectly white ; it was then taken out
of the crucible and reduced to a granular powder ; two parts of
potassium were then introduced into a common test-tube. Care
should be taken to remove the white crust which usually covers
potassium, as it occurs in the country ; this coating is hydrate of
potash generated by the action of water contained in English naphtha.
If German naphtha is employed to preserve the potassium there
is little or no hydrate of potash formed. The quantity of water in
English naphtha is sometimes so considerable, that I have actually-
seen potassium take fire when introduced into it. For the speci-
men of potassium with which the present experiments were made,
I am indebted to the kindness of Mr. Graham of Glasgow. To pro-
ceed with the process : the potassium, cut into minute fragments,
was mixed with one part of the granular boracic acid described ;
the tube was then cautiously exposed to the flame of a spirit lamp;
scanty white fumes began to be discharged; as soon as they ceased
to be formed, the mixture was heated to redness, and the process
continued for ten minutes; when the tube had cooled, a drop of
water was introduced in contact with this mixture by means of a
glass rod; no action occurred, showing that no potassium was pre-
sent ; a quantity of water was then introduced into the tube, mixed
with some muriatic acid ; the tube was washed out, and the con-
tents thrown upon a filter ; the boron was well washed and dried ;
it possessed a fine deep brown colour, and was entirely converted
into boracic acid by ignition with nitrate of potash.

The improvements, therefore, in the process for preparing boron
now described, consist, 1st, in pointing out the probable cause of
former failures, viz. the employment of potassium containing water;
and 2nd, the use of boracic acid in a granular or rough state, which
enables the decomposition to go on slowly, and thus prevents the
rapid union of elements either foreign or essential to the process.
We are thus enabled to witness the whole operation ; no violent
action occurring to prevent the performance of the experiment in
a glass tube." British Annals of Medicine ^ Feb. 1837.

3H2

420 Intelligence and Miscellaneous Articles.

EXPERIMENTS ON CAMPHOR.

MM. Dumas and Peligot have made the following statements as
the results of their experiments on common camphor : Neutral and
oxygenated organic bodies, when their vapour contains half a volume
of oxygen, approximate alcohol in general in the nature of their re-
actions. This is at any rate what happens with the spirit of wood,
oil of potatoes, ethal, and pyroacetic spirit. This generalization
struck us long since, and we have subjected common camphor,
which is so constituted, to the action of some bodies which would
allow of procuring from them decisive products, admitting that
camphor would act like alcohol. We shall limit ourselves to stating
here, that common camphor, treated with anhydrous phosphoric
acid, 'furnishes a liquid volatile oily carburetted hydrogen composed
of C'*" H^S; this then comes from the camphor, as if this body, being
formed of C^o H^s, H^^ O^, should lose its water under the influence
of the phosphoric acid. On acting upon camphor by sulphuric
acid, a light volatile oil is also obtained.j It appeared to us to be
formed of the carburetted hydrogen preceding and camphor, in va-
riable proportions. By rectification with anhydrous phosphoric
acid, it resolves always into the carburetted hydrogen C^^ H^^
already mentioned. V Institute April 3, 1837.

COMPOUND OF ALBUMEN AND BICHLORIDE OF MERCURY. BY
M. LASSAIGNE.

It has long been known that a solution of bichloride of mercury
precipitates a solution of albumen, even when very dilute. This
fact, which proves both the strong mutual action of those bodies
and the slight solubility of the product, has been employed by Dr.
Bostock as a method of distinguishing albumen from gelatin and
mucus, and of recognising it in the animal fluids. In 1813, M.
Orfila proposed white of egg or albumen as an antidote for corro-
sive sublimate, conceiving that the insolubility of the product of
their reaction, if it would not neutralize, would at least diminish
the deleterious property of the mercurial chloride.

M. Orfila considered the precipitate formed as composed of al-
bumen and protochloride of mercury, while M. Chantourelle, in
1822, considered it as a compound of albumen and the bichloride
of mercury.

In order to discover the facts of the case, M. Lassaigne under-
took some experiments, detailed in a memoir presented to the In-
stitute. He ascertained that the precipitate obtained by mixing an
excess of solution of bichloride of mercury with a solution formed
one part of white of egg and six parts of water, retained from 81*5
to 82 parts of combined water in 100. He considers the moist
precipitate as M. Chantourelle does, as very slightly soluble in
water. He ascertained also that it is dissolved by the chloride,
bromide, and iodide of potassium, sodium and calcium, and by the

Intelligence and Miscellaneous Articles, 421

phosphoric, sulphurous, liydrosulphuric, arsenic, acetic, oxalic, tar-
taric, paratartaric, and malic acids. But the nitric, sulphuric, hydro-
chloric, hydriodic, and gallic acid are not capable of dissolving it.
It is soluble in the cold solutions of potash, soda, ammonia, and
lime. These solutions, after some days, yield a deposit of finely
divided mercury. M. Lassaigne is of opinion that the alkali gives
rise to a chloride or an alkaline hydrochlorate and peroxide of mer-
cury, which ctissolves with the albumen in the excess of alkali over
that which produces the alkaline chloride or hydrochlorate.

M. Lassaigne thinks that in the precipitation of the albumen by
the bichloride of mercury, the two bodies combine integrally, as
supposed, but not proved by M. Chantourelle.

The following, among others, are two facts upon which this opi-
nion is founded : 1st. If a proper quantity of protochloride of tin
be added to a solution of the albuminous precipitate in water satu-
rated with common salt, a white precipitate of protochloride of
mercury is formed ; this is precisely the result obtained, as is well
known to chemists, from a mixture of protochloride of tin and bi-
chloride of mercury ; the excess of chlorine over that which forms
a protochloride of mercury, converts the protochloride of tin into
bichloride, provided always that that protochloride of tin is not in
too great excess, in which case metallic mercury is procured.

2nd. If Eether be agitated with the solution of precipitated albu-
men in water saturated with chloride of sodium, and if the aethereal
fluid be separated when it has become clear, there is obtained on
evaporating it a residue of bichloride of mercury and chloride of
sodium.

In order to justify the conclusion which M. Lassaigne draws from
this fact he adds :

a. That aether which is put in contact with protochloride of mer-
cury, not only does not dissolve it, but does not convert it into
mercury and bichloride, by the aflfinity which it might possess for
the latter.

b. That the solution of the albuminous mercurial compound in
chloride of sodium, having the property of coagulating, like a con-
centrated aqueous solution of albumen. The corrosive sublimate is
found in the water which remains after the coagulation of the ori-
ginal solution ; but the author remarks that the greater part of the
bichloride remains combined with the coagulated albumen.

c. That even the most finely divided protochloride of mercury
does not combine with albumen dissolved in water. M. Lassaigne
has made numerous other observations on the mutual action of
albumen, of bichloride of mercury, and of chloride of sodium. For
example, he has found :

(«.) That a solution of two atoms of bichloride of mercury and
three of chloride of sodium does not precipitate a solution of al-
bumen ;

(h.) That albumen which is precipitated cold by bichloride of

422 Intelligence and Miscellaneous Articles.

mercury, is in the state of albumen which M. Chevreul lias called
soluble, to distinguish from coagulated albumen {I'albumine cuite),
which is insoluble in water ;

(c.) That a solution of precipitated albumen and bichloride of
mercury in a solution of chloride of sodium, is coagulated by heat,
like pure albumen, except that the coagulum retains some bichlo-
ride, and that this solution evaporated in vacuo, separates from the
chloride of sodium in the state of albumen, combined with bichlo-
ride of mercury insoluble in water.

Admitting as exact the atomic constitution which Thomson has
calculated from the analyses of Thenard and Gay-Lussac, M. Las-
saigne considers that the precipitate consists of one atom of bichlo-
ride of mercury and ten atoms of albumen, which gives for 100
parts 6*67 of bichloride and 93*33 of albumen.

M. Lassaigne concludes his memoir with an examination of the
action of bichloride of mercury upon the fibrin extracted from
blood. He shows that a solution of bichloride of mercury in which
fibrin has been placed for several days does not contain any free
hydrochloric acid, as has been stated ; for mercury agitated with
the liquor separated from the fibrin, precipitates all the bichloride
in the state of protochloride, without leaving any hydrochloric acid
in the water. M. Lassaigne has likewise determined the absence
of chlorine in the same liquor separated from fibrin. He concludes
from this double experiment that fibrin, like albumen, combines
with bicldoride of mercury without converting it into protochlo-
ride. Ulnstituty April 5, 1837.

(ENANTHIC ACID.

(Enanthic Acid, separated as just described, is to be carefully
washed with hot water. It may be afterwards dried either by
shaking it with chloride of calcium, or exposing in vacuo to con-
centrated sulphuric acid. The hydrated oenanthic acid thus ob-
tained, is perfectly white, and at about 60° is of the consistence of
butter, but at a higher temperature it melts, becomes a colourless
oil, which is both inodorous and insipid, reddens litmus, dissolves
readily in the caustic and carbonated alkalis. This acid, like all
the fatty acids, forms two series of salts, one of which is acidulous,
without, however, exhibiting any sensible acid reaction, the other
is neutral, with a strongly marked alkaline reaction. It is readily
soluble in aether and in alcohol. When a hot solution of cenanthic
acid is saturated with potash, so that it exhibits neither acid nor
alkaline reaction, on cooling there is formed a pasty mass con-
sisting of fine, extremely fine silky needleform crystals, which are
the acidulous salt of potash.

When oenanthic acid is dissolved with heat in a solution of car-
bonate of soda, and the solution is evaporated to dryness, and then
treated with alcohol, neutral oenanthate of soda is dissolved, and the

Intelligence and Miscellaneous Articles, 423

carbonate of soda remains. The solution of the cenanthate forms
on cooling a semi-transparent gelatinous mass.

If oenanthic acid be added to a cold solution of acetate of lead,
white flocks of an insoluble salt are immediately formed. Acetate
of copper produces an analogous decomposition ; these are acidu-
lous salts, which are insoluble in water, but dissolve readily in
alcohol ; they may be obtained in crystals by allowing a saturated
alcoholic solution to cool.

It is, however, extremely difficult to obtain by this method the
salts free from all adherent acid. If they are washed with alcohol,
they are then decomposed into more acidulous salts and subsalts.

(Enanthic acid appeared to be composed of

Thirteen equivalents of Hydrogen 13

Fourteen equivalents of Carbon 84«

Two equivalents of Oxygen 16

113

Its combining weight appears to be about the same, judging
from the composition of cenanthate of copper, and supposing it to
be composed of one equivalent each of acid and base.

METEOROLOGICAL OBSERVATIONS FOR MARCH 1837.

Chisivick, — March I — 5. Bleak and cold. 6 — 8. Fine, but cold.

9. Cloudy. 10. Cloudy: rain. 1 1. Very fine. 12. Clear and frosty :
sleet. 13. Cloudy and cold. 14. Very clear: stormy at night. 15. Bleak
and cold. 16. Drizzly: hazy. 17 — 19. Cold and overcast. 20, 21. Snow
showers. 22. Cloudy, 23. Cloudy: frosty at night. 24. Very severe frost
for the period of tlie season : clear and cold, 25. Cold and dry.

26 — 31. Excessively dry and cold.

It will have been observed in the monthly extracts from the Meteoro-
logical Journal kept at the garden of the Hoiticultural Society at Chiswick,
that the extremes o^ the max. and jnin. columns have hitherto been inserted
at the bottom of the columns containing the indications of the barometer
and thermometer. Instead of this, in future, at the suggestion of Dr.
Lindley, it is proposed to give the means of the respective columns, the ex-
tremes of highest and lowest being easily found, if required, by inspection.
R. Thompson.

Boston. — March 1 — 3. Cloudy. 4, Stormy. 5. Fine. 6. Cloudy.
7. Fine. 8. Cloudy. 9. Cloudy : rain p.m. 10. Fine. 11. Fine;

snow at night. 12. Rain. 13, 14.Fine. 15 — 18. Cloudy. 19.Fine.
20. Cloudy: snow early a.m. 21. Snow. 22. Fine: snow early a.m.

23. Fine : snow a.m. and p.m. 24, 25. Fine. 26, 27. Fine: snow p.m.

28. Cloudy : snow early a.m. 29. Fine : rain and hail p.m. 30. Fine.

31. Fine.

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THE

LONDON AND EDINBURGH

PHILOSOPHICAL MAGAZINE

AND

JOURNAL OF SCIENCE.

■ — f- —

[THIRD SERIES.]

JUNE 1837.

LXXX. Experiments on the peculiar Voltaic Condition of
Iron as excited by Peroxide of Lead ,• in a Letter to Mr.
Faraday. By Professor Schcenbein.*

Dear Sir,

I ONCE more take the liberty to address to you by writing
a short account of the results of* my latest researches on
the peculiar condition of iron. In my opinion, these results,
though they do not yet solve the riddle of the subject, are such
as to excite scientific curiosity, at least as much as the facts
did, a description of which I had the honour to communicate
to you last year. The space allotted to a letter being so small,
I am obliged to be as concise as possible in describing the
phasnomena recently observed by me ; but if you should be
interested with the details of the subject, I take the liberty of
referring you to a paper of mine which will hereafter be
published in Poggendorff 's Annalen. In the first place I must
tell you, that the most powerful voltaic association into which
iron can be brought in order to excite its peculiar condition,
is that with peroxide of lead. A common iron wire, one of
the ends of which is covered with this substance, proves to be
iaactive, not only towards nitric acid of a given strength, but
towards nitric acid -containing any quantity of water ; whilst,
as you know, my oxidized iron wire, or one associated with
platina, &c., is acted upon by that acid if much diluted just in
the same manner as unprotected iron. But the superiority
of the association mentioned to any other at present known is
exhibited in a still more striking manner by putting the two
endsof an iron wire (one of which is covered by peroxide of lead)

* Communicated by Mr. Faraday.
Third Seties. Vol. 10. No. 65. Jutie 1837. 3 I

426 Prof. Schoenbein on the peculiar Voltaic Conditioti of Iron

into an aqueous solution of the common sulphate of copper,
in the same way as the two ends of the oxidized wire, &c. are
plun^^ed into common nitric acid. Under these circumstances
not the smallest particle of copper will be precipitated on any
part of the wire immersed in the said solution. This peculiar
state of the wire, however, lasts only so long as both ends of
it are in the solution ; for no sooner is the protected one
removed from the liquid, than the other left immersed turns
active, that is to say, throws down copper. In this respect,
therefore, there is a great difference between the action of the
wire in question upon the solution of blue vitriol, and that of
the oxidized one upon common nitric acid. This difference of
action implies another, namely, the impossibility of transferring,
within the copper solution, the peculiar state from wire to wire,
which it is so easy to do in nitric acid, I must not omit here
to state the remarkable fact, that by mixing the solution
of the sulphate with a comparatively small quantity of chloride
of sodium (common salt) the calling forth of the peculiar con-
dition is prevented, not only in the foregoing case, but in all
that will be mentioned hereafter. This fact is by no means
an insulated one, and depends upon the same cause as that
which prevents the disengagement of oxygen at the iron (whilst
constituting the positive electrode of the pile) from a solu-
tion of haloid salts, &c. Presuming that by rendering iron
inactive towards sulphate of copper in the way described, a
current would be excited the same as to its direction with that
produced by calling forth the peculiar state of this metal within
nitric acid, and having had recourse to the galvanometer, I
was very much struck on finding that the needle was not in
the least affected. The instrument I made use of in my ex-
periments, though indicating rather weak currents, certainly
does not possess the highest degree of sensibility possible, (it
contains about 100 coils,) but as in a scientific point of view it is
of very great importance to know whether the peculiar condi-
tion of iron can in any way be called forth without exciting
a current at the same time, I beg you to decide this question
by means of your most delicate galvanometer. If your ex-
periments should happen to place beyond doubt the absence
of any current under the before-mentioned circumstance, such
a result would justify the deduction of very curious inferences
from it, and prove in the first place that the inactivity of iron
has, as to its origin, nothing to do with whatwecnll a current.
A series of phaenomena depending upon the action of iron
wire (associated with peroxide of lead) upon a solution of sul-
phate of copper may be called forth, which exhibits a beautiful
analogy to that set of facts communicated to you in my letter,

as excited hy Peroxide of head, 4^7

which you had the kindness to have inserted in the Phi-
losophical Magazine, No. 59. (present volume, p. 133.)
To obtain with iron in the said solution results similar to
those mentioned in my letter, depending upon the action of
this metal on nitric acid, the following conditions must be ful-
filled. In the first and second case the oxidized iron wire
E F is to be replaced by a wire, whose end E is covered with
peroxide of lead : everything else remains the same as stated
in my letter. As to the third fact, C P D is to be an iron
wire having its end D associated with peroxide of lead ; E F
is to be a common iron wire. With respect to the fourth case,
E instead of being oxidized must be covered with peroxide of
lead. To obtain a result analogous to the fifth fact, the iron
wire C P D, its end D being associated with the substance
alluded to, must first be put into the vessels. Supposing D
to be within B, the end E of an iron wire E F is to be plunged
into A, and F afterwards into B. As the third case shows,
F will turn under these circumstances inactive. Things being
in this state, put the one end of a third common iron wire into
B, and afterwards its other end into A, and F will cease to be
in its peculiar condition. Now whatever the number of wires
similar to that E F may be, all their inactive ends being
within B turn active under the circumstances mentioned,
though they do not touch each other anywhere. Concerning
the sixth case, it is obtained exactly in the same manner as
stated in my letter, provided the oxidized end be replaced by
one covered with peroxide of lead. Bending up the common
end of the experimental wire, is, however, not required. The
best way of associating an iron wire with peroxide of lead is,
to make it the positive electrode of a couronne des tasses (con-
taining about a dozen of pairs of copper and zinc), and to put
the free end of this wire into a solution of the common acetate
of lead {saccharum Saturni) for about 8 or 10 minutes. By the
action of the pile the peroxide is deposited on the positive
iron wire.

En passant, I must tell you, that many reasons lead me to
believe, that iron associated with this substance will form the
most pov^erful voltaic element known, and I am just about to
construct a pile of such couples. As to the chemical nature of
the matter producing the colours of Nobili's chromatic scale*
a notice of mine will shortly be published in Poggendorff"s
Annals, from which you will see that your idea upon the subject
is entirely correctt,and that consequently the view of the Italian

* See Scientific Memoirs, parti, page 108.

t Mr. Faraday's opinion upon this subject will be found in the present
Tolumc, p. 176. — Edit.

3 I 2

4J8 Prof. Schoenbein on the peculiar Voltaic Cofidition of Iron

philosopher wrong. Some of the facts regarding the peculiar
condition of iron, and observed by Mr. Noad, are, as you wilt
easily perceive, quite the same as those which were already
stated in my letter above mentioned. In publishing them as new,
that gentleman was most likely not aware of my observations.

I cannot close these lines without expressing you my sincere
thanks for the service which you so kindly rendered me by
forwarding my last paper to the Editors of the Philosophical
Magazine. I am, my dear Sir, very truly yours,

Bale, April 27, 1837. C. F. ScHCENBEiN.

LXXXI. further Experiments on the peculiar Voltaic Condi-
tion of Iron as excited by Peroxide of Lead, By Professor

SCHCENBEIN.

To the Editors of the Philosophical Magazine and JournaL
Gentlemen,

A S Mr. Faraday has perhaps communicated to you a letter
•^■^ of mine lately addressed to him, in which some new facts
regarding the peculiar condition of iron are stated, you will
lay me under many obligations to you by inserting in your
next publication the following remarks. In the letter alluded
to, I stated that by plunging an iron wire associated with per-
oxide of lead into a solution of common sulphate of copper
no current is produced, or rather, that by means of my gal-
vanometer I had not been able to discover one. Having since
made the instrument more delicate, I succeeded the other
day in tracing a current under the circumstances mentioned,
and as it may easily be supposed, a current which originates
in one part of the wire being not covered with peroxide of
lead. From this fact, and those stated in my letter to Mr.
Faraday, it appears in the first place, that iron combined with
the last-named substance and put within a solution of blue
vitriol gives rise to a set of phaenomena, which in every re-
spect are similar to those occasioned by an oxidized or pla-
tinized iron wire within nitric acid ; and in the second place,
that the peculiar condition of iron cannot be called forth by
means of voltaic associations, without exciting at the same time
a current, to which the iron turned inactive bears the relation
of the anode. Now from such an invariable concurrence of
two phaenomena, I think we may safely infer that one of them
is the cause of the other ; and some facts render it probable
that the inactivity of iron is the effect of a current, though
we do not yet know in the least in what manner the first is
occasioned by the latter. If some very weighty reasons did

as ejccited by Peroxide of Lead, 42f)

not militate against the correctness of the idea, it might be
imagined that the connexion between the two phaenomena in
question depends upon the fact, that the current issuing from
the inactive iron carries along with it or keeps at a certain di-
stance from the metal, those particles of the fluid which are
round the metallic substance, preventing by this means imme-
diate contact, and consequently chemical action. This idea
receives some support from the fact, that an inactive iron wire
is to a solution of blue vitriol, as to capillary action, what a
solid body with a greasy surface is to water, whilst such is not
the case with active iron. But the single fact that this metal
can for any length of time remain inactive in nitric acid, under
circumstances which exclude the possibility of the existence
of a current, overthrows at once the aboVe-mentioned hypo-
thesis, not to mention many other facts, equally irreconcilable
with it.

By the relation of iron associated with peroxide of lead to
nitric acid and to the solution of blue vitriol, as well as by the
fact that iron in this combined state excites a very strong
taste upon the tongue, a taste much stronger than that pro-
duced by any voltaic association known, I was led to suppose
that a powerful battery might be constructed of pairs consist-
ing of iron and the said peroxide. Experiments have proved
the correctness] of my supposition : an iron wire 0'"'5 thick,
3" of length, one of its ends coated with a thin film of per-
oxide, and each end put into a separate vessel filled with nitric
acid a hundred times diluted, developed a current which was
capable of decomposing water. For when the two vessels were
connected with a platina wire, hydrogen was evolved at one of
its ends, oxygen at the other. At the extremity of the platina
wire, it being placed in the vessel where the peroxide of lead
was, the latter gas was disengaged. Twenty-four such little
wires arranged into a couronne des lasses and the before-men-
tioned diluted nitric acid used as the exciting liquid, caused
a current of considerable intensity ; for it rapidly decomposed
water only slightly acidulated and produced likewise a sensible
shock. But as may easily be foreseen, such a pile is not active
for a great length of time ; for the hydrogen evolving at the
negative part of each wire, that is to say, at the end covered
with peroxide of lead, rapidly decomposes this substance,
thereby reducing the wire to its ordinary state. Any other
method attempted by me for the purpose of associating the
peroxide with iron than that mentioned in my last letter to
Mr. Faraday proved unsuccessful, though it is possible by
attaching a small quantity of peroxide to a wire in a mechani-
cal manner, to render this inactive in common nitric acid.

499 Dr. Kane on the Protochloride

As to the facts observed by Mr. Noad, you will easily per-
ceive that some of them have been ah'eady mentioned in my
letter to Mr. Faraday, published in Number 5[> of your Ma-
gazine. The conclusion drawn by Mr. Noad from some of
his experiments, that iron being in its peculiar state is inca-
pable of conducting current electricity, is, I am afraid, not
admissible; for as I have shown elsewhere, an inactive iron
wire can perfectly well perform the function of the positive
electrode, even of a very small pile, without undergoing any
change with regard to its peculiar condition ; and besides this
fact, there are many others, which do not allow the adoption
of Mr. Noad's conclusion. It is, however, true, that iron in its
peculiar state obstructs very much the passage of currents of
low intensity, and acts in this respect very like platina.

I am, Gentlemen, yours, &c.
Bale, May 8, 1837. C. F. ScHOENBElN.

P.S. You will oblige me very much by letting Mr. Faraday
have a sight of the preceding letter previously to its insertion
in your valuable Journal. S.

LXXXII. On the Frotochloride and Terchloride of Iodine,
By Robert Kane, M.Z)., M.R.I.AJ^

IN the Jomiial de Pharmacie for February 1837, received
here (at Dublin) April 4th, there is a paper by Soubeiran
in which he describes a chloride of iodine, consisting of three
atoms of chlorine and one of iodine, as new, and as having been
first discovered by him. In the number of the Dublin Journal
of Medical and Chemical Science for July 1833, I described
this very body, as vieW as a lower chloride which appears to
have escaped Soubeiran's notice; and as that memoir has evi-
dently not attracted the attention of chemists, I take the liberty
of subjoining the results contained in it in as brief a form as
admits of their being intelligibly described. The difference of
dates (four years nearly) renders it unnecessary to enter into
any argument about priority.

" In order to obtain a compound containing the greatest
possible quantity of iodine, i passed a current of chlorine
through water in which iodine was diffused, leaving a consi-
derable excess of iodine. The liquor became of a deep
brownish-red colour ; gave off fumes of chloride of iodine
highly irritant to the eyes and nose; had a peculiar smell in-
termediate between those of its constituents; first reddened and

* Communicated by the Author.

and Terchloride of Iodine, 4S1

then bleached litmus paper: when cooled considerably it de?-
posited a considerable quantity of a reddish yellow matter,
which was again redissolved by heat."

For analysis an excess of pure potash was added, the
whole dried and ignited, redissolved and precipitated by ni-
trate of silver, the mixed chloride and iodide of silver sepa-
rated by ammonia. In two analyses were obtained,
1. 2.

Chlorine ... 22-36 23-76 ^^^^ / 23-06

Mean j^^.^

Iodine 77-64 76-24 176-94

100-00 100-00 100-00

The body Cl + I should give

Chlorine 35-42 , 21*9

lodme 126-30 78-1

161-72 100-0

" The solution of this chloride in water is deep reddish
yellow. On the skin it produces a deep yellow mark, and
smarting is not soon washed off. When heated it is partially
decomposed, and by frequent distillations can be completely
decomposed into iodine and the terchloride.

" When put in contact with the red oxide of mercury, the
red or brown oxide of lead, or the oxides of copper, there is
oxygen copiously disengaged, while chloride and iodide of the
respective metals are produced, and some iodine deposited.
With oxide of zinc this reaction is particularly remarkable.
The action of this chloride of iodine on metallic chlorides
gives rise to some interesting phaenomena, which are exhibited
in a tabular form in the original paper, to which I shall refer
for the details. With protochloride of tin, the protochloride
of iodine gives perchloride of tin and protiodide of tin in
splendid orange prisms; iodine being separated by the first
action but subsequently dissolved. Thus,

3(C1 + St) + (C1 + I) = 2(Cl2 + St) + (I + St);

and with other protochlorides the metal is carried to the
highest degree of combination with the chlorine."

" Of the Terchloride of Iodine, — When a solution of the
protochloride of iodine has been repeatedly distilled, the quan-
tity of iodine which separates each time diminishes, until at
last a liquor is obtained which is vaporized unaltered. It then
contains terchloride, although it is exceedingly difficult to
obtain it pure. It can likewise be obtained by adding to
protochloride of iodine a strong solution of corrosive subli-
mate, which throws down much iodine ; and on pouring off

4«32 Dr. Kane on the Protochloride and Terchloride of Iodine.

the clear liquor and distilling, the terchloride can be gotten
nearly pure. A great number of analyses were made of it,
which, though the specimens prepared in different ways and
at different times gave results slightly varying, all agreed within
narrow limits with the formula 3 Cl + I, which gives

Chlorine... 35-4<2 x 3 = 106*26 45*66

Iodine 126*30 = 126*30 54*34

232*56 100*00

" The properties of this compound, admitting its existence,
are, generally speaking, similar to those of the protochloride,
with one exception, which serves to distinguish it from it, and
to determine when it is rendered impure by admixture with
any of it. When the terchloride of iodine is mixed with
protochloride of tin, iodine is thrown down ; but when more
chloride of tin is added, in place of forming the orange-red
crystals of protiodide of tin with the excess of protochloride
of tin, the iodine dissolves and forms a perfectly colourless
solution ; therefore, in distilling the chloride of iodine, as long
as the distilled liquor forms any orange-red crystals with an
excess of protochloride of tin, it has not been as yet freed suf-
ficiently from protochloride of iodine."

Soubeiran doubts altogether the existence of the perchlo-
ride (€15+ 1), in consequence of his not having been able to
obtain it pure. I have not myself made any experiments on
that subject, but from the positive results of Davy and Gay-
Lussac, I am still disposed to admit of its existence and to
consider that there are three chlorides of iodine, CI I, CI3 I,
and CI5 I.

I cannot conclude this note without expressing the great
pleasure I received from seeing my early results confirmed by
the accurate experiments of Soubeiran, and in stating that
although obliged by justice to myself to call the attention of
chemists to my former paper, yet that the recent memoir in
the Journal de Pharmacie has filled up an important vacancy
in science, by showing that the terchloride was of a more per-
manent nature and could be obtained by simpler processes
than I had been inclined to suppose; and I am sure had
Soubeiran attempted to analyse the compound with maximum
of iodine, he would have much illustrated the history of that
body, which I was able at the time but partially to explore.

Dublin, April 12, 1837.

[ 433 ]

LXXXIII. On the Thermo-electric Currents developed be-
tween Metals and Fused Salts, By Thomas Andrews,
M.D., Professor of Chemistry in the Royal Belfast Institur-
tion. *

T^HE interesting discovery made by Faraday of the high
-■" conducting power of certain fused salts for voltaic electri-
city, led me to expect that electrical currents might be pro-
duced by bringing them into contact with the metals, analo-
gous to the thermo-electric currents observed by Seebeck.
Having easily succeeded in verifying this conjecture, and
having observed that the currents thus produced exhibited
some remarkable properties, I submitted them to a careful
examination, the result of which forms the subject of the pre-
sent paper.

To detect the presence of the electrical current, a very de-
licate galvanometer, constructed for me by M. Gourjon of
Paris, was employed, in which the copper wire made nearly
3000 revolutions round the lower needle, and the system of
needles was rendered as perfectly astatic as possible. A gal-
vanometer having 20 or 30 coils, with astatic needles, will be
found, however, sufficiently sensible to give decided indications
of the passage of the principal currents which I shall have oc-
casion to describe.

Having taken two similar wires of platina (such as are used
in experiments with the blowpipe), and connected them with
theextremities of the copper wire of the galvanometer that has
just been described, I fused a small globule of borax in the
flame of a spirit-lamp, on the free extremity of one of the
platina wires, and introducing the free extremity of the other
wire into the flame, I brought the latter, raised to a higher
temperature than the former, into contact with the fused glo-
bule ; the needle of the instrument was instantly driven with
great violence to the limit of the scale. The direction of the
current, as indicated by the deflection of the needle, was from
the hotter platina wire through the fused salt to the colder
wire. A permanent electrical current in the same direction
was obtained, by simply fusing the globule between the two
wires, and applying the flame of the lamp in such a manner
that, at the points of contact with the fused salt, the wires
were at different temperatures.

To discover whether the current had sufficient intensity to
pass through acidulated water, a column of water (to which
a few drops of sulphuric acid had been added), whose length
was about half an inch, was interposed in the course of the

• Communicated by the Author.
Third Series, Vol. 10. No. 63. June 1837. 3 K

434 Prof. Andrews on the Thermo-electric Currents

circuit, the connecting poles in the water being formed of
platina wires. On fusing the globule as before, the needle of
the galvanometer was still deflected through an arc of 80° or
90°, but with less violence than when a complete metallic cir-
cuit was employed. When carbonate of soda was substituted
for borax in these experiments, similar but more powerful
currents were obtained.

My first attempts to obtain chemical decompositions by
means of these currents were unsuccessful when the common
forms of apparatus were used; but by employing poles ex-
posing unequal surfaces, this object was finally attained*. A
piece of bibulous paper, exposing on each side a surface of
one fourth of a square inch, was moistened with a solution of

* The influence of the surface of the poles, in rendering perceptible the
separation of the elements of an electrolyte, is very remarkable. Faraday
has observed that not a bubble of gas will appear on the surface of a pair
of platina plates, immersed in dilute sulphuric acid, when made the poles
of a voltaic combination, formed liy a single pair of platina and zinc plates
charged with the same dilute acid; and hence that distinguished philosopher
has inferred, that the tension of such a current is too low to effect the de-
composition o'i water. On repeating and varying the conditions of this
experiment, I found that if two fine wires were substituted for the platina
plates the same negative result was obtained ; but that if a platina plate
exposing an extensive surface to the liquid was used as one pole, and a fine
wire of the uame metal as the other, then a minute stream of bubbles of
gas arose from the wire, which after continuing for some time finally ceased
to appear. An additional quantity of gas was, however, easily procured,
either by increasing the surface of the broad pole, or by removing it and
heating it to redness, or by reversing the direction of the current. The
following appears to be a satisfactory explanation of these results. When
the poles exposed on both sides equal surfaces, the gases were dissolved
in the nascent state by the surrounding liquid ; but when the polar sur-
faces were unequal, the solution of the gas being greatly facilitated by the
broader pole, the element Ki'i the water separated there was dissolved,
while the other element was disengaged, in the gaseous state, at the wire
which served as the opposite pole. Indeed, Becquerel had already cor-
rectly inferred, from the circumstance of the plates acquiring polarity, that
the water in this experiment of Faraday must have been decomposed. It
is frou) the obstacle presented to the passage of the current by the acquired
polarity of the platina plate, that the gas soon ceases to be formed in
greater abundance than it can be dissolved by the water; and its reap-
pearance under the circumstances stated liefore, is an obvious consequence
from the well-known properties of polarized plates. By employing a si-
milar artifice, a solution of suljjhate of soda may be decomposed by means
of a single couple of platina and zinc plates, charged with a solution of chlo-
ride of sodium, and the presence of the free acid or alkali rendered evident
by its action on litnms or turmeric paper. In order therefore to discover, in
case of difficulty, whether an electrical current is capable of decomposing
water or other substances, it is necessary to employ poles having very un-
equal surfaces ; and this will be effected in the most perfect manner by
opposing a thick wire or plate of platina to one of Wollaston s guarded
points.

developed between Metals and fused Salts. 4S5

the iodide of potassium, and laid on a platina plate, which
was in metallic connection with one of the platina wires used
in the previous experiments. The extremity of the other pla-
tina wire in contact with the globule, was applied to the sur-
face of the bibulous paper, and the flame of the lamp was so
directed, that the latter was the colder of the wires between
which the globule of borax or carbonate of soda was fused.
The platina plate in this arrangement therefore constituted
the negative pole, and the extremity of the wire applied to
the bibulous paper, the positive pole. Accordingly, when the
circuit was completed, an abundant deposition of iodine oc-
curred beneath the platina wire. When a similar wire of
platina was substituted for the plate on the negative side, the
effect was either none or scarcely perceptible.

A compound arrangement was next formed by placing a
series of platina wires on supports, in the same horizontal line,
and fusing between their adjacent extremities small globules
of borax. The globules and wires were exactly similar to
those that are used in blowpipe experiments. A spirit-lamp
was applied to each globule, so as to heat unequally the
wires in contact with it; and the corresponding extremity of
each wire being preserved at the higher temperature, the cur-
rent was transmitted in the same direction through the whole
series. By connecting the extremities of four cells of this ar-
rangement with an apparatus for decomposing water, in which
the opposite poles consisted of a thick platina wire and a
guarded platini point (both being immersed in dilute sul-
phuric acid), very minute bubbles of gas soon appeared at
the guarded point, and slowly separating from it ascended
through the liquid. They were obtained in whichever di-
rection the current was passed, but rather more abundantly
when the point was negative and the wire positive. With only
two cells, similar bubbles formed in a visible manner on the
guarded point, but in such exceedingly small quantity that
they did not separate from it. With an arrangement con-
taining 20 cells, a doubtful sensation was communicated to
the tongue when the poles were applied to 't ; but no spark
was visible, although the current was passed through a helix
of copper wire surrounding a bar of iron, and the contact was
broken with great rapidity by means of a revolving apparatus.
It is necessary to observe, however, that the lamps were unpro-
tected, and that it was impossible to render the flames of such
a number of spirit-lamps burning near each other, so steady
as to heat at the same moment, in the required manner, all
the globules and wires. With an enlarged and more perfect
form of apparatus, there can be little doubt that a spark might
be obtained.

3K2

4S6 Prof. Andrews on the Thermo-electric Currents

The extremities of the platina wires which were introduced
into the globules of borax, after having been employed in
these experiments, did not exhibit any appearance of chemical
action ; their lustre was untarnished, and their edges presented
a sharp and well-defined outline, without being in the least
degree rounded away. To render still more certain the abs-
ence of any chemical action, a very fine wire of platina was
used as the hottest wire, in contact with the fused borax, and
the circuit being completed by a metallic wire, a continuous
current was maintained for several hours; but there was no
apparent change either in the wires or the borax. With carbo-
nate of soda instead of borax, the result was the same. When
it is remembered that this current, if transmitted through a
solution of the iodide of potassium, (in which case the greater
part of the current is even interrupted,) would have produced
in a few seconds a very perceptible deposition of iodine, it is
impossible to imagine that the same current could continue,
for a long space of time, to be produced from chemical action
in one of the platina wires without any sensible alteration of
the metallic surface. Besides, it is well known that under or-
dinary circumstances there is no chemical action exercised by
platina upon fused borax or carbonate of soda.

It is certainly very interesting to see powerful chemical af-
finities thus overcome by simply bringing two metalHc wires,
at different temperatures, into contact with a fused salt, be-
tween which and the wires no [chemical] action takes place.
The direction of the current is not influenced by the quantity
of surface in contact with the wires, but depends altogether on
the difference of temperature, as was ascertained by careful
experiments.

Similar results were obtained when other fused salts were
substituted for borax, such as carbonate of potash, chlo-
ride and iodide of potassium, sulphate of soda, chloride of
strontium, &c. Even with boracic acid, which Faraday has
observed to be a very imperfect conductor of voltaic electri-
city, I succeeded in deflecting the needle of the galvanometer
through an arc of 40°, the circuit being closed by metallic
wires. The direction of the current was the same as with
borax.

To compare the intensity of these currents with those pro-
duced by chemical action, the galvanometer and a hydro-
electric couple were both interposed in the course of the cir-
cuit, and the connections were so adjusted, that the currents
developed by the fused salt and in the voltaic cell should be
in opposition to each other. In this case the deflection of the
needle would indicate the current of superior intensity. On
comparing these currents with various hydro-electric com-

developed between Metals arid /used Salts. 43T

binations, they appeared, when fully developed, to have a
somewhat superior tension to the currents produced by a
couple of platina and silver plates immersed in dilute sul-
phuric or nitric acid. If the nitric acid was so strong as to
dissolve rapidly the silver, then the voltaic current became su-
perior.

The effect of substituting other metals for one or both of
the platina wires still remained to be examined ; but here con-
siderable difficulties often arose, from the fusibility and ten-^
dency to oxidation of many of the metals.

When the platina wires were replaced by wires of palladium,
currents in every respect similar were obtained.

When platina was opposed to palladium, gold or silver,
fused soda or borax being interposed, the current was always
from the platina through the fused salt to the other metal,
provided the platina was at a higher temperature. When the
palladium was hotter than the platina, the current was re-
versed, or from the palladium to the platina. It was difficult
to expose the gold or silver wire to a higher temperature than
the platina without fusing it, when a globule of soda or borax
was used; but by substituting a more fusible globule, formed
of a mixture of the carbonates of soda and potash, the current
was readily obtained from the silver or gold to the platina, so
long as the former metals were maintained at a higher tem-
perature.

These experiments prove that the position of the metals in
the thermo-electric scale does not exercise any influence upon
the direction of the current, which is altogether determined
by the relative temperatures of the wires.

When platina at a higher temperature was opposed to
copper, fused borax or soda being interposed, the current in
very numerous trials (with one or two rare exceptions) was
from the platina through the salt to the copper. It was only
when from the action of the flame a very rapid formation and
solution of the oxide of copper occurred, that the reverse cur-
rent was obtained ; but when the chemical action was not con-
siderable the current was always from the platina. A current
was also obtained in the same direction with boracic acid in-
stead of borax. These results are the more interesting, as
they prove most distinctly that chemical action cannot be the
source of these currents, since in this example the platina
would require to have been the metal attacked.

On substituting iron for copper a violent chemical action
took place, the borax or soda became dark and opake from
dissolving the oxide of iron, and the direction of the current
was in general from the iron to the plalina, even when the

438 Prof. Andrews on the Thermo-electric Currents

latter was at a much higher temperature than the former.
However, by fusing a small globule of borax or soda on an
iron wire in the reducing part of the flame, and bringing a
hot platina wire into contact with it, I obtained a current
from the platina to the iron ; but the experiment is difficult
to perform and will rareU' succeed.

When platina was opposed to the following metals, viz.
antimony, lead, zinc, and tin, it was with some difficulty that
even a mixture of the alkaline carbonates was maintained in
a state of complete fusion, the platina being at a red heat,
while the other metal was itself almost at the point of melt-
ing: the current was in every case from the platina through
the fused salt to the other metal. In these cases it was evi-
dently impossible to reverse the temperature of the metals.
When the interposed globule consisted of chlorate of potash,
the current was always from the oxidable metal to the platina,
but here the chemical action was very considerable. In the
case of the noble metals, the direction of the current was the
same with the chlorate of potash as with the other fused
salts.

It appears from the preceding experiments, that an elec-
trical current is always produced when a fused salt capable of
conducting electricity is brought into contact with two metals
at different temperatures; and that when chemical action does
not interfere, the direction of the current is not influenced by
the nature of the salt or metal, being always from the hotter
metal through the fused salt to the colder metal. "J'his cur-
rent has an intensity inferior to tliat of the hydro-electric cur-
rent developed by platina and zinc plates, but greatly superior
to that of the common thermo-electric currents, and is capable
of decomposing with great facility water and other electro-
lytes. The source of this current may probably be simply
referred to the contact between the heated metal and fused
salt, which appears to be capable of generating an electrical
current, more intense as the temperature of the point of con-
tact is more elevated. According to this view, opposite cur-
rents are developed at the point of contact of each metal with
the fused salts; but that which is produced at the point whose
temperature is higher, having a superior intensity, overcomes
the other, and its effects alone are exhibited ; just as happens
when two similar metallic junctions in a closed metallic circuit
are exposed to unequal temperatures. The superior intensity of
this current to those obtained from the metals alone, depends
probably on the greater obstacle presented to the reunion of
the two electricities, at the junctions where they are separated,
from the inferior conducting power of the fused salt.

■developed beiwee?i Metals and fused Salts. 4'3g>

Hitherto I have only described the currents produced
when the interposed salt is in a state of perfect fusion, but
before the salt becomes actually fused, electrical currents are
developed, whose direction no longer follows the simple law,
that has been before enunciated, but varies in the most sin-
gular and perplexing manner. After a long and tedious in-
vestigation, 1 have been completely baffled in my attempts to
discover the essential conditions upon which the directions of
these currents depend, and I shall therefore describe at pre-
sent only one or two experiments which will show the com-
plicated nature of the inquiry, and may, perhaps, draw the
attention of others to this curious part of electrical science.
In the investigation of these currents a very sensible galvano-
meter must be employed. ^

A small piatina spoon was partly filled with fused carbo-
nate of soda, and the end of a thick wire of the same metal
was introduced into the fused salt, metallic contact being care-
fully avoided. When the salt had cooled, the wire and spoon
were connected with the galvanometer. On applying a very
gentle heat to the bottom of the spoon, by means of a small
spirit-flame placed at a considerable distance, a current was
obtained from the spoon to the wire, or from the hot metal
to the cold ; this current was very feeble and could rarely be
maintained beyond a few minutes. By increasing the tem-
perature of the lower part of the spoon till the salt in contact
with it entered into fusion, while the portion surrounding the
cold wire was still in a solid state, a powerful current was ob-
tained from the wire to the cup, or from the cold metal to the
hot. When the temperature of the cup was still further raised
so as to fuse the whole of the salt, the current was of course
again reversed, being from the hot metal to the cold. It was
interesting to observe the violent manner in which from this
cause the needle of the instrument started from one extremity
of its scale to the opposite, on the slightest movement of the
flame.

To the class of partially fused salts belongs heated glass,
which accordingly presented similar changes in the direction
of the current. Thus when a piatina wire was covered with
a very thin coating of glass, and another wire at a higher tem-
perature brought into contact with the glass, the current was
from the cold metal through the glass to the hot. If a thicker
piece of glass was interposed, the first current was from the
hot wire to the cold, but on raising the temperature a current
was obtained in the opposite direction. M. Becquerel had
already observed by means of a sensible gold-leaf electroscope
that when piatina wires at unequal temperatures are separated

440 Mr. WestwoocVs Descriptions of some new

by means of heated glass, they exhibit signs of free electricity,
one of them being connected with the ground and the other
with the electroscope; but the general conclusion which he
attempts to deduce from the result of this single experiment
is certainly inaccurate, as it is founded on the assumption that
the colder wire will give always signs of positive electricity,
which we have seen is only true when the glass is thick and
at a certain temperature. The conditions however here stated
are not the only circumstances which influence the direction
of the electrical currents with heated glass, but as my expe-
riments do not lead to any definite result, I refrain from de-
scribing them.

These currents may likewise be obtained by interposing
certain minerals between unequally heated wires ; thus mica
placed between platina wires and heated very strongly caused
a deflection in the galvanometer needle of 7°, and the mineral
called stilbite of 25° ; the current in both cases was from the
hot platina to the cold,

Belfast, April 11,1837.

LXXXIV. Descriptions o^ some new British Species of Hy-

menopterous Insects, By J. O. Westwood, F,L,S, Sfc, *

Encyrtus Dalmanni.

CAPITE thoraceque laete aureo- vel coeruleo-viridibus sericeis, scutello
obscuriori; antennis thorace brevioribus sensim incrassatis, articulis
3 — 8, apice 9vi lOmiet 11 mi omnino albidis; alis anticis nigricantibus, costa
versus et pone medium obscuriori, basi, maculis duabus marginalibus op-
positis fasciaque subapicali albis ; abdomine chalybeio ; femoribus nigricanti-
bus; tibiis tarsisque anticis luteis, summo apice fusco, tibiis intermediis flavis
basi nigris, tibiis posticis nigris, tarsis pallide luteis. Species pulcherrima.
— Long, corp.f lin. Expans. alar. H lin^

Habitat in quercetis com. Oxon., Cantian. et Surrej. Tempore aestatis.
In mus. nostr.

Encyrtus Zetterstedtii.

Praecedenti valde affinis. Capite thoraceque laet^ viridi-coeruleis, sericeis ;
abdomine nigro-chalybeio ; antennis nigris, articulis 7 et 8 albidis, summo
apice fuscescenti ; alis anticis nigricantibus, sutura obscuriori, basi, macula
oblong-i ante medium alterisque 4 oppositis, 2, 2, marginalibus albis ; pedi-
bus nigris ; femoribus et tibiarum basi pedum anticorum nigris, tibiarum
apice tarsisque fulvis, tibiis intermediis et tarsis flavis illorum basi nigris,
tibiis posticis nigris summo apice luteo, tarsisque luteis. — Long. corp. ^ — |
lin. Expans. alar. 1 — H lin.

Habitat cum praecedente. In mus. nostr.

Encyrtus albipes.
Thorace viridi-a;neo tenuissim^ punctate ; capite viridi, fronte viridi-
aurea; antennis fere longitudine corporis, luteis, pilosis, filiformibus, scapo
albo-flavescenti ; scutello cupreo, laminis pieurarum violaceis, pedibus gra-

* Coramunicated by the Author.

British Species of Hymenopterous Insects, 44?1

cilibiis albo-flavescentibus, tarsoruin apicibus fiiscis; abdomine nigro-aenco ;
alis oninrno hyalinis. $*

Encyrto zejihyrino Dalm. vald^ affinis. — Long. corp. 4 lin. Expans.alar.
1? lin.

Individua 22 e larva Tortricis ciijusdam folios involutos TUice habitantis
excliisa. Dom. Ingall. In mus. nostr.

EnCYRTUS SULPHUREirS.

Paljide siilpbiireus; oculis, antennaniin clava tarsornmque apice fiisco.
Abdomine sessile, thorace majori ovato depresso apice siibattenuato, alarum
nervis pailidis, antennis capite cum thorace baud longioribus, versus apicem
paulo et sensim incrassatis. — Long. corp. \ lin. Expans. alar. 1 lin.

Habitat in gramineis in Richmond Park. Fine Augusti 1833. In nius.
nostr.

Encyrtus Schcenhbrri.

Luteus, sericens ; antennis fuscis, filiforniibus, scapo ovali compresso
albido, fascia lata nigra; apicibus albidis ; facie ^ulva; metatborace ob-
scuro, abdomine parvo, conico, depresso; pedibus luteis; alis hyalinis im-
niaculatis. — Long. corp. 4 lin. Expans. alar. H lin.

Habitat prope Cantabrigiam, Windsor et Hampstead Heath, mense Julio.
In mus. nostr.

Encyrtus Dahlbomii.

Thorace aeneo tenuissime punctate ; abdomine nigro orbicul^to de-
presso; facie fulva, vertice nigro; antennis sensim clavatis nigris, scapo
latissimo compresso subtriangulari, articulis tribus ultimis (arctissime con-
junctis) albis; pedibus luteo-rufis ; femoribus tibiisque posticis obscuris ; alis
fascia lata media fusca. — Long. corp. 1 lin. Expans. alar. I4 lin.

Habitat in gramineis apud Swanscombe, com. Cantian., Julio 1835.
In mus. nostr.

Encyrtus Bohemanni.

Obscur^ niger; capite thoraceque pubescentibus; abdomine oblongo-ovato
depresso piceo ; tegulis marginibusque scutelli luteis; antennis longioribus
fere filiformibus, scapo maximo compresso fere orbiciilari, articulis ultimis
albis; pedibus luteis, posticis paullo obscurioribus, alis immaculatis. — Long,
corp. f lin. Exp. alar. I5 lin.

Habitat in gramineis apud Richmond Park, com. Surrej, Julio 1835.
In mus. nostr.

Encyrtus hederaceu?.

Albo-canescens ; antennis pallide fuscis sensim crassioribus, apice albo;
facie lutea capite thoraceque testaceis, hoc griseo squamoso, collari albido ;
abdomine parvo orbiculato depresso fusco ; pedibus fusco-albidis ; tibiis
posticis obscurioribus.

Affinis E. punctipedi.— Long. corp. ^ lin. Expans. alar. 1 lin.

Habitat in Hedera, Chiswick. Julio 1834. In mus. nostr.

De genere Choreic (Choreia Westw. Mag. Nat. Hist., vol. vi.;
Grantor HaL Eiit. Mag., No. iv. p. 268.)

Genus olim characteribus e foemina desumptis institutum, nunc charac-
teribus masculinis emendo.

Corpus S breve crassum apterum ut in fcemina. Differt praecipue an-
tennis masculinis corpore toto paulo longioribus filiformibus 1 1-articulatis,
scapo brevi ; articulo 2do brevi, 3tio sequentibus |longiori 4 — 8 aequalibus.
brevioribus, tribus ultimis arctissim^ conjunctis. Reliquis cum fcemina
convenit. . .

Third Series, Vol. 10. No. 63. June 1837. 3 L

442 Mr. A. Essex's Account of the ''

Typiis Choreim inepttis. <? . ? .

Nigro-aeneus ; antennis piceo-rufis, basi apiceque nigris ; pedibus piceis ;
tibiarum apice tarsisque riifis.

Chore'm nigro-isnea. Westw. loc. cit.

Encyrtus ineptus. Dalm. Esenb. Hym. Mon. 2. 255.

Sjjhenolepis inepta. Esenb. loc. cit. p. 258.

Obs. 1 . Genus Sphenolepis Esenbeckii, omnino distinctum nee ad siib-
familiam Encyrtides pertinet.

Obs. 2. Individua nonnulla foeminea cum speciminibus apteris cepi, alas
qnatuor perfectas nigricantes possidentia. Haec pro specie diversa non
considero; sed potius individua evolutionem perfectiorem gaudentia; spe-
ciminibus alatis VelicB currentis analoga. Nihil inter insecta Hymenoptera
huic simile adhuc observatum est.

Agonioneurus albidus, Westw.

Totus pallid^ flavescenti-albidus; oculis obscuris; alis immaculatis albidis,
longe ciliatis, callositate stigmaticali magis conspicua quam in Ag. basalii,
angulum parvum cum margine alarum formanti, antennarum articulo 5to
prsecedenti multo majori. — Long. corp. ^ lin. Expans. alar. | lin.

Habitat — ? In mus. nostr.

Agonioneurus subflavescens, Westw.

Totus pallidissime flavescens ; oculis ocellisque paulo obscurioribus; alis
subhyalinis, flavido vix tinctis callositate stigmaticali quam in Jg. albido
minus distincta, antennarum articulo 3, 4 et 5 aequalibus.

Obs. Insectum vix conspicuum. — Long. corp. \- lin. Expans. alar. 1 lin.
In mus. nostr.

Habitat in sepibus apud Sylvam Coombe, aestate 1835.

LXXXV. Some Account of the Art of Painting in Enamel,

By Mr. Alfred Essex.*
T^HE perusal of the excellent paper on Glass-painting wiiich
appeared in the Philosophical Magazine for December
1S36, having revived an idea which I had formerly entertained
of drawing up for publication a brief view of the allied art of
Painting in Enamel, I have now endeavoured to bring my
intention into effect. This art is mentioned in some former
papers in the Magazine, but as it is usually introduced merely
incidentally, some further account may not be unacceptable to
the present readers of this work.

Before proceeding to my more immediate subject, allow me
to make a remark or two on that of painting on glass.

Mr. J. T. Cooper observes, in a paper on " the Composi-
tion of the Ancient Ruby Glass f," that " the chief difference

between the ancient and modern ruby glass consists in the

hardness, or infusibility of the basis on which it is flashed, that
which is now manufactured being of flint, while the former is

• Communicated by the Author.

t Annals of Philosophy, Second Series, vol. vii. p. 105.

Art of Painting in Enamel, 443

of the hardest crown glass; also the difficulty of obtaining it
of any size, and free from cloudiness or opacity." These ob-
jections, I understand, apply equally to that which is made at
the present time* ; to which it may be added that the modern
ruby glass is inferior to the ancient in this respect also, that
while the latter, on being exposed to the heat of a glass kiln,
preserves its colour unimpaired, that of the former suffers
considerable injury by such exposure, in some cases becoming
almost black. The importance of this difference will be duly
estimated when it is considered that, in consequence, the
modern ruby cannot be painted upon, as the heat required to
fix the fresh colour would destroy the beauty of its original
appearance. To meet this difficulty the modern artist has
recourse to the following ingenious expedient. He paints
upon a piece of plain glass the tints and shadowy necessary
for blending the rich ruby glow with the other parts of his
picture, leaving those parts untouched where he wishes the
ruby to appear in undiminished brilliancy, and fixes the ruby
glass in the picture behind the painted piece. Thus in such
parts the window is " double-glazed."

Your " Correspondent" says that " the material employed
by the old glass-makers to tinge their glass red was the
protoxide of copper ;" but it would appear from the ana-
lysis made by Mr. Cooper that the colouring material was
not copper alone, for he states that he obtained in the process
*' a copious precipitate of chloride of silver."

It is generally believed, as stated also by the author of the
paper on " Glass-painting," that copper yields the green in
enamel-painting. This statement is true if it is confined to the
productions of those artists who practised painting in enamel
prior to the late Mr. Charles Muss. He employed, as I do,
the oxide of chromium to produce this colour, and discarded
copper altogether : in the composition of enamel colours, I en-
tirely reject also the use of iron and manganese.

In the paper on Glass-painting now referred to, it is ob-
served that " the accounts to be found in various works re-
specting this curious art are by no means satisfactory or com-
plete :" this observation may be extended, without offering the
least violation to truth, to the equally curious and beautiful
art of Painting in Enamel. Writers on the subject of ena-
melling confound the art of painting in enamel, with those of
painting on glass and porcelain, although these three arts are
almost as dissimilar as their products, — a painted window, a
richly ornamented vase, and an enamel painting.

Enamel is a substance having for its basis a white and per-
* Mr. Cooper's paper appeared in 1824.
3 L 2

44-4 Mr. A. Essex's Account of the

fectly transparent glass. When a small quantity of oxide
either of gold, silver, cobalt, copper, or some few others
of the metals is added to this base it produces a coloured
transparent enamel. This enamel is used on silver and gold,
and is applied to the ornamenting of snuff-boxes, watch-cases,
and various articles of jewellery. Previously to the applica-
tion of the enamel, various patterns and devices are bright-
cut in the metal with the graver or the rose-engine, and the
cuts, reflecting the rays of light from their bright and nu-
merous surfaces, exhibit through the richly coloured enamels
a beautiful and gorgeous play of colours sparkling in varied
forms with every change of aspect. Sometinies this enamelled
bijouterie is further adorned with paintings in enamel, execu-
ted on rich transparent grounds, when, in some ijistances, a
sunlike splendour is imparted to the whole scene by the rays
of the engine-turned gold shooting from behind the moun-
tains in a landscape, or diverging from the bosom of a lake.
The enamel which, when painted upon, produces the most
agreeable effect in these applications, is that which is opal-
escent, and which by enamellers is called opal; the soft cream-
coloured and fiery appearance of the gem being imparted in
this imitation by the oxide of arsenic.

When oxide of tin or of antimony is added to the transpa-
rent base mentioned above, the result is an opake enamel.
I suspect, but am not certain, that oxide of antimony enters
into the composition of some of the Venetian enamels. 1 have
made an enamel with it alone, as the colouring matter, whiter
than some specimens of foreign manufacture, and having in a
high degree the waxlike appearance formerly so much valued
by the makers of enamel clock- and watch-tiial plates. But
oxide of tin is certainly the substance to which opake enamel
commonly owes its opacity and whiteness*.

The enamel used for making the plates upon which paint-
ings in enamel are executed is imported from Venice. It is
in the form of round cakes, varying in size from three to seven
inches in diameter, and from half to three quaiters of an inch
in thickness, and weighing from half a pound to three pounds
each. It is cream-coloured, heavy, less brittle than glass, is
sufficiently hard to scratch crown-glass ; its fracture is con-
choidal and exhibits a resinous lustre, and it fuses at a tem-
perature a little below that which will melt gold. Its com-

« There is a substance made at the glass-houses near I^ondon, the coni-
merciai name of which is glass- enamel^ that owes its measure of opacity
and whiteness to the oxide of arsenic. It is very glassy, brittle, easily
scratched, readily fusible, and very white. It is used for making the com-
mon kinds of clock- and watch-dials and the white semi-opake ornanients
for the mantel-i;heU, toilet, &c.

Jrt of Painting in Enamel, 445

mercial value varies from 12 to 20 shillings per pound. I have
not analysed it, but its constituents, as stated by various au-
thors, are silica, an alkali, and the oxides of lead and tin, and,
I suspect, as before observed, oxide of antimony also.

An enamel colour is, like enamel, composed of a colourless
and perfectly transparent glass for its base and owes its colour
to a metallic oxide. Thus silica, borax, and the red oxide of
lead form a base or flux for some colours. The habitudes of
the oxides require that each should be treated with reference
to its peculiar qualities, for instance, the flux which when em-
ployed with gold is best adapted for the production of a beau-
tiful colour, is inefficient if used with the oxide of cobalt.

The plates for paintings are prepared thus: a plate of gold,
or more usually of copper *, is covered with three successive
layers of enamel, the enamel having previously been ground
in an agate mortar; each layer requiring to be passed through
the fire and melted before the next is laid upon itf. The
plate being thus prepared, the artist proceeds in painting the
picture in a similar manner to the painter in oil or in water
colours, accordingly as the subject may require. The prin-
cipal difference is this, that instead of waiting for the colours
to dry before proceeding to lay on another coat, the painter
in enamel has his work passed through the fire. By this pro-
cess the colours are completely vitrified, and are incorporated
with the body of the plate. This is not so completely the case
with paintings on glass and on porcelain. The colours on
these usually adhere only to the surface, and, under some cir-
cumstances, they are known to chip ofF|. Glass and porce-
lain, also, do not admit of being subjected to so high a tem-
perature as enamel plates, and hence the colours for painting
on those substances are manufactured to melt at a much lower
degree of heat than those used by painters in enamel. This

* The French and other Encyclopaedias state, that silver is used for this
purpose ; and Walpole, in his "Anecdotes of Painting, &c." says that Petitot
used plates of silver. This cannot be correct, for silver has the property
of cracking the enamel in all directions every time it is past>ed through the
fire, and hence it becomes necessary to expose plates of that metal when
enamelled, to a sharp heat, in order to flow the enamel, that the cracks may
close. This it is obvious would effectually destroy the drawing of a picture
if it did no other injury. Silver is therefore only used for transpareitt
enamelling, but in this application it is not so rich and beautiful as gold,
and is only employed when the high value of gold is an object of considera-
tion, as in the silver stars which are worn by the members of certain orders
of knighthood, masonic emblems, military ornaments, &c.

f For a particular account of the manipulations practised by the ena-
meller, see the article Enamelling in Rees's Cyclopaedia. In this article the
details are minutely faithful, though with reference to dial-plates modern im-
provements have rendered obsolete most of the processes describeil in it

X See Broneniart " On the colours obtained from the metallic oxides,"
&c. Phil. Mag. First Series, vol. xiii. p. 342 ct seq.

44«6 Mr. A. Essex's Account of the

property of easy fusion is obtained by the introduction of a
larger proportion of oxide of lead or of alkali, or of both, into
the composition of the colours ; which superabundance renders
the flux of the colours an imperfect glass, and consequently
lays it open to decomposition, from the attacks of those gases,
which, being continually evolved from putrescent and other
substances, are ever floating in the atmosphere.

The difficulty of working the colours with delicacy, and the
extreme care required in eff*ecting this, render the process of
painting in enamel slow, and hence it has seldom been applied
with success to painting from life, but has usually been em-
ployed in copying*. Indeed its permanency obviously points
out, as perhaps its most legitimate use, the transmission to
posterity of faithful transcripts of those eminent works which
time is daily injuring and is certain ultimately to destroy. To
effect this object no other branch of art appears competent.
Engraving is adequate to transmit light and shadow, design
and drawing, but colouring is wholly unattainable by it. But
how much of the beauty and merit of a fine work of art is
dependent upon its beauty of colouring ! Nor can the richness
and sweetness of a good colourist be attained either on glass
or on porcelain, the chemical action induced by these sub-
stances, when at a high temperature, being inimical to really
good colouring, while that of enamel, on the contrary, tends to
impart depth and sweetness to every tint. Another advantage
possessed by enamel over glass and porcelain is worthy of
notice, and this is, that while the latter do not admit of being
subjected to the fire more than from three to five times, the
former knows no other limit than the finish of the picture.
Paintings in enamel are usually passed through the fire ten or
twelve times, and indeed sometimes oftener. This unlimited
application of his efforts affords to the artist the opportunity
of imparting to his work the finish of a Gerard Douw and a
Mieris, and also of attaining with precision the deep, rich,
and sweet tones which are seen in the productions of Cor-
reggio, of Guido, of Rubens, and of Reynolds.

To obtain the richness of the master-colourists it is obviously
necessary that the painter in enamel should be in possession
of colours capable of emulating those of the painters in oil.
In this however the artists of former times were sadly defi-
cientf. But, fortunately for this durable and beautiful art,

* Walpole states of Petitot, that " His custom was to have a painter to
draw the Hkenessin oil, from which he made his sketches, and then finished
them from the life."

t Dr. Ure in his Chemical Dictionary gives, from the Transactions of
the Society of Arts, what he terms •* A valuable list of receipts for enamel
colours." The unfortunate artist who shall attempt to make colours for the

Ari of Pai filing in Enamel. 447

the discoveries of modern chemistry have afforded the ma-
terials to supply this long-sought desideratum. From three
of the metals which till lately were known but to chemists,
and which were regarded as curiosities only, namely, platinum,
uranium, and chromium, are already produced four of the
richest and most useful of the colours on the palette of the
painter in enamel. And doubtless we may look to this source
for the means for further improvement. Before the introduc-
tion of oxide of platinum a positive rich brown was unknown in
enamel* : this colour when produced by the mixture of others,
as was previously the practice, was liable to alteration by re-
peated fires, becoming more opake and meagre, and acquiring
somewhat the appearance of common brown clay. With
such a material how was it possible for an artist to obtain that
deep, rich, and juicy transparency which is so highly and justly
valued by every judge of painting, and which distinguishes the
works of the great masters both ancient and modern ? The
oxide of platinum on the contrary yields a beautiful, indestruc-
tible, and richly transparent enamel brown, which no intensity
or frequent application of the furnace can injure.

Mr. Cooper observes f that with the black oxide of platinum
" we can now produce an enamel colour which preserves an
intense black in the lighter shades, and is, moreover, capable
of sustaining the most violent fire, without injury, which none
of the former colours [blacks] will bear, without change." On
this 1 must remark that I have made many experiments with
this oxide, but have never been able to produce with it an in-
tense black enamel colour. A black it certainly will produce,
but not of sufficient intensity to be useful to the painter. I have
a black of great intensity which is unchangeable in the fire,
and into the composition of which the black oxide of platinum
does not enter. I have exposed this colour to the heat of an
enamelling furnace about forty times without any apparent al-
teration of its tint or diminution of its intensity.

Colours proper for painting in enamel are not to be pur-
chased : those sold for the purpose are adapted only for paint-
ing on china. I have devoted much time to their improve-

purpose of painting in enamel from these receipts will assuredly find, to his
disappointment, that they are utterly useless. The statements made in books
upon vitrifiable colours are really unaccountable, and truly does M. Brong-
niart observe in his essay, that " it is very remarkable, that if the processes
described in these works were strictly followed, it would never be possible
to form the colours for which they pretend to give recipes ;" and M. Clouet
is justified in exclaiming as he does of the authors, " None of them say what
they ought respecting enamel." (Phil. Mag., First Series, vol. vii.p. 3.)

* For this invaluable acquisition the enamel painter is indebted to the
late talented and indefatigable Mr. Muss.

t Journal of the Royal Institution, vol. iii. p. 121.

448 Mr. A. Essex's Account of the

ment for the use of my brother Mr. William Essex, Painter in
Enamel to H. R. H. the Princess Augusta. One of the objects
which I have endeavoured to accomplish, and in which I have
not been unsuccessful, is, that they should be of the same co-
lour when on the palette as they will be when they have passed
through the fire. The colours possessing this property, the
artist is enabled to see while proceeding with his wor-k, the
precise effect that will be produced after the painting has un-
dergone fusion. Thus the power of attaining greater preci-
sion in imitating the original is secured.

In Brongniart's " Essay on the colours obtained from the
metallic oxides and fixed by fusion on different vitreous bodies,"
which has been before quoted, it is observed that oxides "which
adhere little to the great quantity of oxygen they contain, can-
not be employed The colour they present cannot be de-
pended on, since they must lose it in the slightest heat by
losing a part of their oxygen." This assertion looks very
well in theory, but I confess I was surprised to find such a
statement put forth by an able practitioner. In his paper on the
black oxide of platinum*, Mr. Cooper observes, "A curious
property of this oxide should here be mentioned. When
heated per se, or with combustibles, it is easily reduced, but
when mixed with enameller's flux, it is capable of sustaining
a very intense heat, without decomposition ; indeed it has with-
stood reduction in the most violent degree of heat I was able
to give it." To this may be added, that no colours are more
to be depended upon, more indestructible in the fire, than
those prepared from the oxides of platinum and of gold; and
yet of the oxides of these metals it may be said, in the lan-
guage of M. Brongniart, that they above all others " adhere
little to the oxygen they contain," they standing lowest among
the metals for affinity for oxygen f .

Ever}^ person at all acquainted with the receipts for enamels,
as framed by those who had not that light to guide them which
is afforded by modern chemistry, must be aware of the strange
jumble which they almost universally present. Feeling certain
that here, as in every other instance in which excellence is
sought, simplicity was desirable, I have kept the attainment of

* Journal of the Royal Institution, vol. iii. p.. 121.

t See a paper by V. Regnault in the Number for August, 1836, of the
Annates de Chimie et de Physique, which appears to give the latest results on
this subject. I am aware that it is conceived by Prof. Proust and others
that the gold in the powder of Cassius, (which is employed to produce a
purple colour in enamel,) is not in the state of oxide. Various considera-
tions, however, have led me to a different conchision, and I am much
pleased to find that I am supported in this opinion by authority so eminent
as that of the late Dr. Turner. See his Elements of Chemistry, Fifth Edi-
tion, p. 645.

Art of Painting in Enamel. 449

this in view tlirouivhout the experiments which I have made
for the purpose of obtaining a set of enamel colours which
should combine with the required richness of tone and bril-
liancy of tint, the property of remaining unchanged during the
numerous exposures to the heat of the furnace to which a
painting in enamel is necessarily subjected. Of the necessity
for simplification, and also of the extent to which it is capable
of being carried, take the following example.

In vol. xxxv. of the Transactions of the Society for the En-
couragement of Arts, &c. p. 49, it is stated, that " Twenty
guineas were this session (1817) voted to Mr. R. Wynn for
receipts for enamel colours and for staining and gilding on
glass." One of these receipts, for green, is given thus, at p. 60 :
*' A frit for transparent greens.

" Take flint powder 3 ^

Flux No. 2 (p. 55) 3 I

Green pot-metal glass H L

Red-lead 7i f

Raw borax 2^ ■

Green oxide of copper 1 ^ J

" Melt them in a crucible, pour out the mass, and pound it
in an earthen mortar.

Take of the green frit 3

Of yellow enamel colour (p. 56) 1^

" If too soft add Naples yellow."

Now in order to see the whole complexity of this receipt let
us make an analysis of its contents ; and then contrast it with
the simplicity which experience shows to be attainable.

Frit.
Flint powder 3

®* fp'iJ^^ r Silica . . . . l 1

b I White arsenic 1 f

S LNitre IJ

Green f Silica 'j

pot- J Alkali I ,,

metal \ Oxide of lead,
glass. [, Oxide of copper J

Red lead 7^ ^ "o

Raw borax 2| j 13 ^

Green ox, of copper M J C!

O

Of this when melted take 3

"Z fRed-lead 81

Oxide of antimony 1 l 1 ")

I «* I White oxide of tin

•^=, ^ fRed-lead 91") |

---^ 6 I Borax 5| 1 >H

'^ <j?v . r Silica .... 1 >H

I t^^^^^-lOx.oflead
Here it may be observed that silica is introduced in four

* This receipt for " yellow enamel colour" is given by Mr. Wynn at p. 56
of the volume referred to.

Third Series. Vol. 10. No. 63. June\S%l. 3 M

i^O Mr. A. Essex's Account of the

different instances, and oxide of lead in six, and except one
instance of introduction of the former substance, and two of
the latter, the artist must of necessity be ignorant of the pro-
portions in which they exist in the artificial compounds which
he employs. Foreign substances also are present, such as
iron, manganese, &c., which, altliough in minute quantities, are
injurious and create confusion. These are not noticed in the
foregoing analysis, because their introduction or omission, as
likewise their proportions when introduced, are dependent
upon accident and the pleasure of the manufacturer.

Let us now proceed to contrast this complex process with
the result which some attenticm to the progress of chemical
science has enabled the enameller of the present day to arrive
at. The following are at once the materials and substantially
the constituents of the green enamel colour which Mr. W^
Essex has in use :

Silica.

Borax.

Oxide of lead.

Oxide of chromium.
Here the simplicity is such that all the substances which
enter into the composition of the colour are known to the
maker, and the proportions in which they shall exist are en-
tirely within his command.

The enamelling- furnace, in which the smaller plates are pre-
pared and the smaller paintings also Jired, is a square space of
about twelve inches in height, in depth, and in width, surroun-
ded by solid brickwork, and opening into a vertical flue in which
is a register for regulating the heat. It is elevated a convenient
height from the ground, and has an iron plate hearth in front
for the purpose of holding the plates and paintings both before
and after they have passed through the fire. The bottom of the
furnace, when prepared for use, is covered to about three
inches in thickness with coke%upon which the muffle is placed.
The nmffle has neither bottom nor back, and is surrounded

• The old enamel painters had a notion that no fuel but charcoal was
suitable for an enamelling furnace. The late Mr. Hone held this opinion^
and the late Mr. Grimaldi frequently had fires made with charcoal alone
for his paintings, because, as was imagined, the colours '• came out bet-
ter;" but I never could discover that those paintings which were treated
with charcoal displayed any superiority over those which were fired with
coke. In conjunction with Mr. Muss I made several experiments to test
the truth of this notion, and these proved it to be fallacious. Coke is by
much the more convenient substance, as its combustion is slower, and con-
sequently the heat can be maintained without interruption for a longer time
by its means than with charcoal, than which it is also very much cheaper.

Art of Painting in Enamel. 1-51

with coke except in front An iron door, having an aperture in
it the size of the front of the muffle, closes the whole. The
entire draught of air supplying the furnace passes through the
muffle. The plates and paintings are placed on thin slabs,
made of tempered fireclay, technically termed planches. When
the fire has burnt up sufficiently, the plate or painting, after
having been dried by being placed on the iron plate opposite
the fire, is gradually introduced under the muffle, the planch
resting on the bed of coke. The greatest heat, it is obvious,
will exist at the back of the muffle; it is necessary therefore
that the picture should be turned while in the fire that it may
be heated equally over its entire surface ; this is effected by
means of a pair of spring tongs. When the colours are seen
to be properly melted the painting is wkhdrawn and placed
on the iron hearth to cool. In this furnace plates are prepared
and paintings fired from the smallest size up to about five
inches in diameter; but for larger works a furnace of a different
construction is required. The muffle of the large furnace has
a bottom and a back, and its mouth is closed also by a door
made either of iron or of fire-stone. From the circumstance
of its thus being closed on all sides it has acquired the ap-
propriate appellation of a close miiffle, that before described
being termed, in contradistinction, an open muffle; the essen-
tial difference being that while the entire draught of the fur-
nace passes through the latter, it is wholly excluded from the
former. In the large furnace the fire is placed under the
muffle only, and is supported by iron grate-bars, the construc-
tion, in fact, closely resembling that of a common air-furnace.
The draught passes between the bars and carries the flame
into the flue, which commencing at the top of one of the sides
of the fire-place, conducts it over the muffle, which it leaves^
by means of flues constructed in the same plane with its bottom,
on the side opposite to that at which it enters. The flame after
enveloping the muffle plays against the bottom of an iron oven.
This oven contains several shelves, and its use is, to anneal the
paintings, this being necessary to prevent them from cracking
when in the fire, which they would do if exposed suddenly to
the heat of the muffle. The furnace is so arranged that the
bottom of the annealing oven becomes of a dull red heat at
the time when the muffle attains the proper state for receiving
the paintings, and this is indicated by its interior becoming
of a glowing orange heat, the muffle itself having to sustain a
heat nearly adequate to the fusion of cast-iron. By this ar-
rangement the paintings, as they are placed in the annealing
oven while it is cold, are gradually heated until they arrive at
a temperature at which they can with safety endure the much

3M2

452 Mr. A. Essex's Account of the

higher heat of the muffle. They are likewise returned to the
oven after they have undergone superficial fusion in the muffle,
it being requisite that their cooling also should be effected
gradually.

Painting in enamel having been reproached in the hearing
of Mr. Muss as a style of art in which neither texture nor
crispness was attainable, because, as was alleged, the colours
when in fusion would flow smooth and mingle, Mr. M., being
conscious that enamel possessed the capabilities of the styles
both of oil and water, determined practically to vindicate his
art from the reproach. For this purpose he painted that un-
equalled production in enamel, the Greyhound, which now
forms part of His Majesty's collection. The original, by
J. Ward, R. A., is painted with all that bold crispness for which
the works of that eminent artist are celebrated, and in the
enamel this peculiarity is faithfully preserved. By what means
Mr. Muss accomplished this, is not fully known ; but my
brother, when copying a picture by Sir David Wilkie, having
occasion for crisp painting, 1 undertook some experiments with
the view of furnishing him with colour possessing the required
quality of melting soundly, but retaining at the same time the
sharpness and precision of form with which it had been touched
on. The result of these experiments was the production of
colour which, though completely vitrified, will, if required, re-
tain even the sharpness of a needle point. In fact, transpa-
rency, crispness, and texture, (as indeed my brother's works
may evince,) are now equally attainable in enamel as in any
other mode of painting.

The nature of the material and the expense attendant upon
attempts to produce large works have tended to restrict the
dimensions of enamel paintings. Until the time of the late
Henry Bone, R.A., Painter in Enamel to His Majesty, but few
attempts had been made to extend the size beyond that suit-
able for trinkets. That artist, with amazing perseverance and
industry, overcame innumerable difficulties, and exhibited an-
nually, tor a long series of years, enamels of large dimensions.
Petitot, whose works are usually minute, painted, it appears,
a picture "9| inches high by 5| wide* regarded by Walpole
as indubitably the most capital work in enamel in the world ";
but in this attempt he seems not to have been quite successful,
for*' the enamel is not perfect in some trifling parts*": this
picture is stated " to be in the collection of the Duke of De-
vonshire*." In the reign of Queen Anne an artist named Boit
undertook a painting in enamel of the extraordinary size ot

♦ Walpole's " Anecdotes of Painting."

Art ofPaiftting in Enamel, 453

"from 24- to 22 inches high by 16 to 18 wide." He, however,
failed to produce the picture, after having received an ad-
vance of 1700/., and having expended upwards of 800/. in
fruitless attempts to accomplish his object*. It appears, there-
fore, that the largest works which have been executed in
enamel are, the Bacchus and Ariadne, after Titian, by Bone ;
and the Holy Family, after Parmegiano, by Muss.

Mr. Bone's picture measures 18 inches by 1 6^, and was paint-
ed after the original by Titian, now in the National Gallery.
It was purchased of the artist by the late George Bowles, Esq.,
for 2200 guineas, and was subsequently in the possession of
the Hon. Miss Rushout.

Mr. Muss's picture measures 20^ inches by IS^t, and was
painted after the original by Parmegiano, in the possession of
Sir Thomas Baring, Bart. Upon the decease of the artist it
was purchased by His late Majesty George IV., for the sum
of 1 500 guineas, and now forms part of the Royal Collection
at Buckingham Palace. This great work then, it would ap-
pear, is the largest painting in enamel that has hitherto been
executed.

It may be assumed that in general painting in enamel is
best adapted for pictures of smaller size, yet in some cases cir-
cumstances may exist which render it desirable that a painting
should be perpetuated in an enamel of even larger dimensions
than those just noticed, and in the present state of the art no
insuperable difficulty exists to the accomplishment of such an
object.

Whether, participating in the general fate of the produc-
tions of man, paintings in enamel will, in the lapse of ages, alter,
fade, and resolve into their original elements, is a problem the
solution of which must be left to future generations. Never-
theless their power of extreme duration is established by the
fact that some rude specimens of vitrified colours have been
found in Egypt, which have existed between two and three
thousand years, but which still appear as fresh as if they were
but the productions of yesterdayj. This power of resisting
decay renders enamel a valuable medium for conveying down
the stream of time the likenesses of celebrated individuals.
Portraits, whether executed in oil or in water colours, change
in a comparatively short period, the rosy tints becoming pale,

* Walpole's Anecdotes of Painting.

f The plate was made for Mr. Muss by the writer of this paper.

X It does not appear that the Egyptians practised enamelling on metal.
Specimens of gold inlaid with enamel exist in the collection of Egyptian
antiquities at the British Museum, but none in which the enamel has been
vitrified on the metal.

iSi Dr. G. O. Rees on Hydrate of Magnesia.

and the high lights sallow ; and where the delicately transpa*
rent tints shed their deepening beauty opacity gradually su-
pervenes. But those which are fixed in enamel will carry on
unchanged to a period indefinitely remote the most delicate
as well as the richest of the tints originally imparted by the
pencil of the artist; and as he left the portrait of the sage, the
poet, the warrior, and the beauty, so will they remain, when
even the marble which portrayed their forms or told their
history may have crumbled into dust.
35, Northampton-street, Clerkenwell, March 1837.

LXXXVI. On Hydrate of Magnesia, By G. O. Rees,
M.D., KG.S., Src.

To Richard Phillips, Esq., F.R.S., Sfc,
Dear Sir,

SHOULD you think the following worthy of notice, pray
favour me by inserting it in the Philosophical Magazine.
Your sincerely obliged,
59, Guilford Street, Russell Square, G. O. Rees.

May 16, 1837

It has been supposed by some chemists that magnesia is
capable of uniting with water in several proportions, though
no analysis seems to have been made of the artificial hydrate
of that earth. The native hydrate of magnesia from America,
analysed by Dr. Bruce, yielded in 100 parts,

Magnesia 70

Water 30 100.

A specimen of the same mineral from Unst, analysed by
Dr. Fyffe, yielded in 100 parts,

Magnesia 69*75

Water 30-25 100.

The results of two analyses made by myself of the artificial
hydrate agree very nearly with the proportions obtained by
Dr. Fyffe from the native specimen. Thus in a first experi-
ment 100 parts yielded.

Magnesia 69*63

Water 30*37 100.

A second experiment gave.

Magnesia 6941

Water 30*59 100.

These specimens were prepared by digesting recently cal-
cined magnesia in cold distilled water and then drying the

Replies to Papers o?i various Electrical Subjects, ^55

mixtuft over a water-bath. The first was digested in a well-
closed vessel durin<r fourteen days: but no greater combining
proportion of water was observed than in the second speci-
men, which was only digested for twenty-four hours. — I have
procured a similar result by merely moistening the earth, and
immediately drying it over the water-bath. The combination
is immediate, and, as has been shown, admits of no increase in
the proportion of water by a prolonged digestion. If boiling
water be used in forming the hydrate, no difference is ob-
served in its constitution. It may be remarked how nearly
the first analysis approaches to the proportions of atom to
atom, for assuming 20*7 as the atomic weight of magnesia, we

^»^v^' Magnesia 20*7^

Water ^ 9*02

It seems certain from these experiments, that magnesia is
capable of combining with water in one proportion only.

The precipitate obtained by the addition of ammonia to »
neutral solution of sulphate of magnesia approaches also very
nearly in constitution to a protohydrate of the earth, i found
100 parts of the precipitate (well dried over a water-bath) to

yi^'^ Magnesia 66*7

Water 33*3 100.

LXXXVII. Replies by Mr. E. M. Clarke, the Rev. Professor
Callan, a7id Dr. Ritchie to certain Papers on Subjects of
Electricittj and Magneto-electricity inserted in the preceding
and present Volumes of the Philosophical Magazine.

npHE following is the substance of communications which
^ we have received from the gentleman above named. We
have omitted nothing which could tend to elucidate the sub-
jects under discussion : indeed the reply of the Rev. Professor
Callan to Dr. Ritchie, and that of the latter to the Rev. J. W.
MacGauley, are inserted almost entire.

Reply of Mi\ E. M. Clarke ^o Mr. J. Saxton,(See vol.ix. p.360).

" I proceed to rq^ly to Mr. SaxUm's remarks one by ane.>
In the first place I have not laid claim to the electro-
magnetic machine (as he ealls ii): as my invention, but I have
certainly termedj a magnetic electrical machine E. M. Clarke's,
owing to a material difference having been made in its cow-
struction, the advantages arising from which I shall now pro-
ceed to point out. First, it will readily be admitted that vi-
bration tends to injure the magnets. In Mr. Saxton's machine
very great vibration is unavoidable, in as much as all the ma-

456 Mr. Clarke in reply to Mr. Saxton.

chinery is attached to the magnet: a glance at tlie figure in
Mr. Saxton's paper will at once prove the truth of this asser-
tion. Another disadvantage attending his instrument is, that
the magnetic batter}' cannot be readily detached so as to be
applied to other purposes. Then again comes the mercury
cup with all its attendant trouble and loss of time, owing to
the incessant scattering of the mercury, the necessary filtra-
tions owing to its oxidations, &c.

" Let me now oppose to these evils the advantages which I
may fairly claim as being possessed by my machine. First,
the instrument can be worked without any possibility of vibra-
tion, and the magnetic battery can be withdrawn from the
instrument with the greatest facility. I have now also suc-
ceeded in dispensing with mercury, for a description of the
mode of doing which I beg leave to refer your readers to the
second number of Mr. Sturgeon's « Annals of Electricity,
Magnetism and Chemistry, and Guardian of Experimental
Science,' which also contains a description of my magnetic
electrical machine. ' Mr. Clarke's machine,' says Mr. Sax-
ton, ' differs from mine only in a slight variation in the situa-
tion of its parts.* Every scientific inquirer knows what an
amazing difference a slight variation in the situation of
parts will often occasion in a philosophical instrument. But
to proceed, he continues to say that my instrument is in no
respect superior to his. I have already pointed out a few facts
to prove that it is superior, and shall, ere I conclude, convince
your readers that it is in every respect to be preferred. All
I can expect, all I ask for is fair play. Let the public witness
what Mr. Saxton's machine can do, and all that it can do,
next witness the effects produced by mine, and then let them
decide which they prefer.

" I shall now proceed to another assertion of Mr. Saxton's,
viz., that no description of his machine had been published
previously to the insertion of his attack upon me. Why, a
description appeared in the number of the Mechanics' Maga-
zine for May the 3rd, 1834; again, in Sir Richard Phillips's
work, printed in 1834; again, by Mrs. Somerville; and also
in the Catalogue of the Adelaide-street Exhibition : what, then,
is Mr. Saxton's meaning?

" Let us now examine a little more minutely into the real
facts of the matter as connected with the construction of the
machines. By Mr. Saxton's own showing (fig. 3) the cy-
linders A B, on which the wires for the shock are coiled, are
of the same size as the cylinders C D, round which the short
wires for giving the spark are coiled. My principle is totally
different. Different as regards the size of the cylinders (those

Mr. Clarke in reply to Mr. Saxton. 457

for quantity being double the diameter of the intensity cylin-
ders) ; different as respects the relative thickness of the wires
(the intensity wire being ^'^ of an inch in diameter and 1500
yards long, the quantity wire being -^-^ inch in diameter and
40 yards long) ; different also in my armatures being separate,
for were they to be in one piece, to develop the full effects of
both quantity and intensity the poles of the magnetic battery
should be separated more than three times the distance they
now are by my having the armatures unconnected. And yet
this is what Mr. Saxton would call " a slight variation in the
situation of the parts" !

" I now come to speak of Mr. Saxton's statement respecting
the quantity and thickness of the wire he uses ; for I confess
that I for one, on referring to his figures ^ and 4, cannot ima-
gine that he has ever constructed an instrument of the kind
he describes. It must be evident that the quantity of wire re-
quired for C D, would be so disproporticmate to that neces-
sary for A B, as to render necessary a greater space between the
cylinders C D (containing the quantity of thick wire), and the
cylinders A B, having a smaller quantity of thin wire.

" Again, Mr. Saxton speaks of insulation^ saying that the
front end of the spindle is for that purpose, being made of
ivory or hard wood. Insulation of what ? I use nothing of the
kind ; insulation being quite unnecessary. Will Mr. Saxton
still maintain that my machine does not differ in principle also
on this point ? Next we come to his description of the ar-
rangement for giving the spark. According to his description,
if the blade F leaves the surface of the mercury at the* moment
when the cylinder C D is vertical, then A B being on the mag-
nets, and the current in C D having been for some time neu-
tralized, the proper point would be so far different from what
he states, as, instead of being vertical, to form an angle of
nearly 45°. ' For obtaining the shock,' says Mr. Saxton,
' the points should be removed,' &c. I answer, Let any 'per-
son try to obtain the shock with the points removed.

'* He omits to state to whom he is indebted for the sugges-
tion of removing one of the points. But I shall take the liberty
of doing so, and he will remember that the individual alluded
to was Mr. Ellicott, assistant to Charles Payne, Esq., late the
deservedly respected Superintendent of the Adelaide Gallery,
who is perfectly ready and willing to prove the correctness of
this statement. We now come to what may be called the
historical portion of Mr. Saxton's paper, and here I would
remark, that if I had written a history of magnetic machines,
instead of merely describing my own, and had omitted to
mention any one in particular, I then might have fairly been

Third Series, Vol. 10. No. 63. June 1837. 3 N

458 Mr. Clarke in reply to Mr. Saxton.

accused of being disingenuous ; but I have not proposed or at-
tempted such a history.

" In Paris I was told by Professor Pouillet that there was as
much difference between my machine and Newman's (meaning
Saxton's) as there was between the latter and Pixii's. The same
words nearly were used in London by Dr. D. B. Reid, Messrs.
Sturgeon, Leithead, and BachhofFner; and in Dublin the same
remark was made by Professor Lloyd and Dr. Apjohn, the
former of whom, although previously in possession of Mr.
Saxton's machine, purchased one of mine, and the latter has
actually entrusted to me one of Mr. Saxton's to be altered ac-
cording to my principle of construction for the Royal College
of Surgeons, Ireland. Mr. Saxton next proceeds to state
that until December 1835, he had not added the double arma-
ture, whereas I sold three of my machines with double arma-
tures in the April preceding.

" Mr. Saxton goes on to state that his first idea of the double
armature suggested itself to him on his seeing Count di Pre-
devalli's machine in November 1833. From the same source
I derived my idea, but certainly before Mr. Saxton, in as much
as I had the machine in my hands before he had ever seen it.
I was then in the employment of Watkins and Hill, to whom
this machine was sent on its coming from Paris to be put in
order, and I was the person in whose hands it was placed.
I attended it at the Gallery, and can assuredly state that the
machine did not exhibit the effects stated by Mr. Saxton. It
did not charge the Leyden jar. The electrometer, or rather
the electroscope, was affected, because the jar had been pre-
viously charged with dry electricity, and the residual electri-
city was the cause of the effect attributed by Mr. Saxton to
the magnetic machine. Again, if the idea occurred in 1833,
why did he not put it in practice until 1835 ? The truth is, it
was not until after he had seen my machines with the double
armatures, and after he saw the effects produced by a dwarf
machine of my making, under the directions of Charles Payne,
Esq., deposited in the Adelaide Gallery, as contrasted with
his gigantic instrument. I can, moreover, fearlessly call on
Dr. Faraday to bear me out in my statement that he himself
told me the machine as constructed by me gave more powerful
shocks than any he had previously seen.

With respect to Mr. Saxton's observations of the cause of
the difference between the states which are generally termed
quantity and intensity, I beg leave to offer one or two remarks.
He states that the investigations of Dr. Henry of Philadel-
phia, Mr. Jennings, and Dr. Faraday fully proved that the
spark is best obtained from a magneto-electric coil when short !

The Rev. Prof. Callan in reply. to Dr. Ritchie. 459

Why, according to this, a person unacquainted with the sci-
ence would expect to obtain a spark from a single coil ! ' And
that,' he continues, ' the shock is best when the coil is long.*
My experiments do not bear out this assertion ; my machine
depends upon the thickness of the wire for the spark, and its
tenuity for the shock, within, of course, certain limits; and as
far as I have carried my investigations, with nine pounds weight
of steel, magnetized precisely to that degree which it will re-
tain under all circumstances save being made red hot, a wire y^^
inch thick and 15 yards long gives a certain amount of quantity
effect, 20 yards of the same sized wire gives more, but 25 yards
less ; while, on the other hand, 700 yards of wire -^-^ of an inch
thick gives a certain degree of intensity, but 800 yards of the
same size less. With respect to his assertion that I have no
claim to the double armature, 1 shall not add another word,
confident as I am that I have already fully answered him on
that point, and in a way which I trust will be perfectly satis-
factory both to him and the public.

" With respect to Mr. Saxton stating that my « piracy' con-
sisted not in manufacturing his instrument, but in suppressing
all mention of his name as connected with it, — I certainly
have not manufactured any of his instruments since my im-
proved machine was perfected, although I have had to alter
several, and I do not therefore see what right he has to expect
mention to be made of his name.

" Of his last remark I cannot admit the truth, for so far
from having appropriated to myself Ampere's Bascule electrique,
in a paper of mine in Mr. Sturgeon's Annals, published a
month before Mr. Saxton's attack, I acknowledged the priority
of all similar contrivances of which I had any knowledge."

No. ] 1, Lowther Arcade, Feb. 15, 1837.

The Rev. N. J. Callan, Professor of Natural Philosophy in the
Roman Catholic College, Maynooth, in Reply to Dr. Ritchie.
(See Lond. and Edinb. Phil. Mag., vol. ix. p. 61.)
Dr. Ritchie says that the battery described by me has been
known for a long time. May I ask Dr. Ritchie why he has
not referred to some work where a description of such a bat-
tery is to be found ? He next says that he " had one exactly the
same, ... six or seven years ago. Dr. Ritchie neither describes
his battery nor refers to any description of it ; it is therefore
impossible for me to point out the difference between it and
the battery described by me in the Philosophical Magazine
for December (vol. ix. p. 4-72). With the aid of an electro-
magnet, and a small instrument for rapidly breaking commu-
nication between the battery and helix of an electro-magnet,

3N2

4f60 The Rev. Prof. Callan in reply to Dr. Ritchie.

the battery described by me, though it contains but 20 pairs
of plates, is capable of producing in the space of one minute
3000 or 4000 electric currents, each equal in point of intensity
to that of a battery containing 1000 or 2000 voltaic circles.
That the helix of an electro-magnet is capable of giving a
shock at the moment when battery communication is broken,
was discovered only about two years ago (Phil. Mag. for No-
vember 1834, p. 351); that the shock given by the magnetic
helix increases with the -number of plates employed was not
known till discovered by me within the last year. Surely,
then, Dr. Ritchie had not a battery six or seven years ago,
which, though containing only a small number of plates, was
capable of producing in the space of one minute 3000 or 4000
electric currents, each equal in point of intensity to that of a
battery containing 1000 or 2000 voltaic circles.

Again, Dr. Ritchie says, " the author speaks of a shock as
if it were a quantity^ and institutes a comparison between the
she of the shock and the number of plates." That I speak
of the shock as if it were a quantity, and that I institute a
comparison between the size of the shock and the number of
plates, Dr. Ritchie infers from my saying that " with one pair
of plates the shock from the helix of the electro-magnet was
equal to that of a battery containing 20 pairs of plates; when
two pairs of plates were used, the shock appeared to be doubled;
with three voltaic circles it appeared to be treble ; and with
every increase in the number of voltaic circles, there appeared
to be a proportional increase of the shock." Had Dr. Ritchie
read the remainder of the paragraph from which these words
are taken, he could not but see that his inference is most un-
just. For in the following line I speak of the shock as strong,
and never speak of it as if it were large or had size. The
obvious meaning then of my words is, that the shock increases
with the number of plates, not in size, but in strength or in-
tensity. My language may be inaccurate ; but it is the lan-
guage of Mr. Singer, who, in his treatise on galvanism,
speaks of the shock as increasing : it is also the language of
Dr. Ritchie himself, who says that " the physiological effects
(among which he of course includes the shock) continued to
increase'' (Phil. Mag., June 1836, p. 455.)

Lastly, Dr. Ritchie says, that " the only thing new in my
paper is the affirmation that an electro-magnet, when its mag-
netism is induced by a compound battery of 200 small pairs
of plates, will have a greater power of inducing magnetism at
a distance than any permanent magnet." Dr. Ritchie adds,
" the very looseness of this statement is a proof of its fallacy."
The looseness of this statement is due to Dr. Ritchie himself,

The Rev. Prof. Callan in reply to Dr. Ritchie. 461

who has substituted the indefinite article an for the definite
article the. In my paper it is not affirmed than an electro-mag-
net, but that the electro-magnet, (that is, the electro-magnet
of which I was speaking, or which was formerly used in the
apparatus for continued rotation,) when its magnetism is in-
duced by a battery of 200 pairs of small plates, will have a
greater power of inducing magnetism at a distance than any
permanent magnet ;" that is, than any permanent magnet sub-
stituted for the electro-magnet the use of which has been
abandoned. Dr. Ritchie asks, " does the author mean to say
that a small electro- magnet when connected with a battery of
200 pairs of plates induces more magnetism on soft iron at a
distance than any permanent magnet?" I mean to say, what
my words clearly imply, that the electro-miagnet formerly used
in the apparatus for continued rotation, when rendered mag-
netical by the voltaic current from a battery of 200 pairs of
plates, will have a greater power of inducing magnetism on
soft iron at a distance than any permanent magnet substituted
for the electro-magnet, or than any permanent magnet of
equal or nearly equal size. And this position Dr. Ritchie has
not disproved, nor will he be ever able to disprove.

But is there the slightest foundation for Dr. Ritchie's as-
sertion that the only thing new in my paper is the affirmation
that the " electro-magnet, when its magnetism is induced by a
compound battery of 200 small pairs of plates, will have a
greater power of inducing magnetism at a distance than any
permanent magnet?" I answer that this assertion is utterly
destitute of foundation.

In my paper it is proved, first, that the magnetic power given
to an electro-magnet by the voltaic current, and the distance at
which that power is exerted, increase nearly in proportion to
the number of plates employed ; secondly, that the shock given
by the helix of an electro-magnet, when battery communica-
tion is broken, increases nearly in proportion to the number
of plates employed ; thirdly, that the shock given by a long
wire, on breaking communication with the battery, increases
with the number of plates in the battery ; and fourthly, that
with the aid of an electro-magnet, and of a small instrument
for rapidly breaking communication between the battery and
magnetic helix, a battery containing but 20 voltaic circles
may be made to produce effects of decomposition equal to
those of a battery containing 1000 or 2000 voltaic circles.
Surely, were it in his power. Dr. Ritchie would not have failed
to show by reference to some published works, that I was not
the discoverer of the three above-stated facts, or of the means
of rendering a battery of 20 pairs of plates as efiective in pro-

462 Dr. Ritchie in reply to The Rev. J. W. MacGauley.

ducing decomposition as a battery of 1000 or 2000 pairs of
plates.
Maynooth College, Feb. 12, 1836.

Dr. Ritchie iii reply to the Rev. J. W. MacGauley.
(Seep. 130.)

Mr. MacGauley describes the results stated in my paper
contained in the Phil. Mag. for June 1836, as " perfectly at
variance with the truth." The following is his version of my
statement : " It is a well-known fact, that we receive a more
powerful shock when electricity is being induced on a body,
than when the induced electricity is returning to its natural
state." The quotation is quite correct, — except the substitution
of the indefinite article a, for the definite article the, before
the word body. This slight substitution makes " my talk very
egregious nonsense." My original statement is, that the shock
is most powerful when the electricity is being induced on the
(human) body, and I may further add, that this is always the
case, whether the shock result from a single wire which has
been connected with the voltaic battery, or from the coil of
an electro-magnet. My statement therefore has no reference
whatever to the electric state of the wire, or in other words, to
the question, whether the electricity of the wire is hemg forced
from its state of equilibrium or returning to its natural state.

Mr. MacGauley has also mistaken the experiments of Dr.
Faraday on the length of the coil influencing the electric spark.
His experiments were made with a single wire, either in one
continuous length or in the form of a coil, mth a galvanic
battery alone. The shock from a long wire has long since
been obtained by Professor Henry of America. Mr. Mac-
Gauley speaks of an electro-galvanic h^Yvs. as a species of elec-
tric machine of almost unlimited energy. There is nothing,
however, gained by forming it into a helix, the single con-
tinuous wire of the same length being equally efficacious. The
following quotation clearly shows that the author really knows
nothing of Faraday's admirable investigations : " The asser-
tion I do make is this, and I repeat it, that if the iron of an
electro-magnet retain, from the nature of its material, the pre-
sence of a keeper, or any other cause, the magnetism induced
upon it, the shock and spark will be proportionally diminished,
because the magnetism of the bar, by its inductive action on
the helix, would prevent the perfect restoration to equilibrium
of the electricity disturbed in the helix, by giving to the bar
in a greater or less degree the nature of a permanent magnet,
from which, by means of a helix coiled around it, neither

Dr. Ritchie in reply to The Rev. J. W. MacGauley. 463

shock nor spark can be obtained. Will any one deny this ex-
cept Dr. Ritchie? I believe not."

Dr. Faraday's investigations have completely established
the fact, that it is only magnetism (or the electricity which con-
stitutes magnetism) in motion which can either induce electri-
city on a wire, or partially prevent the electricity already in-
duced from returning to its natural state. A permanent mag-
net then mthin a coil, whilst it remains as such, can have no
influence ^whatever in preventing the " perfect restoration to
equilibrium of the electricity disturbed in the helix." It is
quite true that a piece of soft iron, if it could be placed within
a helix connected with a battery, without having magnetism
induced on it, would partially weaken the returning electricity
in the coil, by the reaction of the electricity induced on it by
the returning current, and the more it differs from a permanent
magnet the more would it act in diminishing the returning
current.

The concluding part of the preceding quotation contains
the following remark. Since neither shock nor spark can be
obtained from a wire coiled round a permanent magnet, there-
fore a permanent magnet can diminish the spark and shock
which the coil would of itself give when returning to its natural
state. If Mr. MacGauley will look at a short paper of mine in
this Number, he will find that both a po^werful shock and a
brilliant spark may be obtained from a permanent horseshoe
magnet having a wire coiled round it.

Mr. MacGauley accuses me of mistaking his results because
he uses a galvanic helix instead of a magneto-electric machine.
Now if I have not always mentioned by name the galvanic helix,
it was simply because the electricity induced on the conductor
is exactly the same whether the inducing cause be a voltaic
battery or a magneto-electric machine.

We have noticed in PoggendorfF's Annalen some remarks
bearing upon several of the controversial papers on subjects of
electricity and magnetism that have appeared in our last and
present volumes, which we feel that we ought not, in candour,
to omit to mention. They occur in a note appended to an
abstract in that Journal of the Rev. Professor Callan's paper
on a new voltaic battery, inserted in our last volume, p. 472.
M. PoggendorfF observes, after referring his readers to a paper
by Dr. Ritchie also in that volume, containing a statement con-
troverted by Prof. Callan, " the same volume of this Journal
[the Philosophical Magazine] contains several other papers
on the subject of magneto-electricity, which, as proofs of the
great interest taken in this branch of natural philosophy in En-

A^Bit Linjicean Society,

gland at the present time, are very agreeable, but the'whole of
which contribute very little to its advancement." He then
notices Mr. Rainey's first paper (vol. ix. p. 72), stating that
the remarkable fact which it describes had before been ob-
served in America by Henry and Ten Eyck*, and had recently
been placed in a clearer light by Prof. G. Magnus, in Pogg.
Ann., vol. xxxviii. p. 436. The subsequent discussion by Dr.
Ritchie and Mr. Rainey is then noticed, and also Mr. Mullins*s
paper (vol. ix. p. 120) and Dr. Ritchie's comment upon it
{ib, p. 222). (PoggendorfF's Annalen der Physik und Chemie,
vol. xxxix. p. 410.)

In the course of his abstract of Prof Callan's paper, M,
PoggendorfF inquires what Prof C. means by " attraction,"
in vol. ix. p. 477. (Ib.) He also notices Mr. Sax ton's account
of his instrument.

L XXXVI 1 1. Proceedings of Learned Societies.

LINN^AN SOCIETY.

May 24, HPHIS day, being the Anniversary of the Linnaean So-

1837. ^ ciety, Edward Forster, Esq., V.P. and Treasurer,
took the Chair, in the absence of His Grace the Duke of Somerset.
Dr. Boott, the Secretary, having stated that the Society had lost,
by death, fourteen Fellows and four Foreign Members, proceeded to
particularize them as follows :

Reo. Sackville Bale, of Withyham, Sussex. — This venerable man
had been a Fellow of the Society for forty-five years, and his life was
passed amid the charities of religion and the peaceful pursuits of na-
tural history. Edward Forster, Esq., one of the Vice-Presidents, and
the Treasurer of our Society, in a letter to me speaks of him in the
following terms : *' My old friend was a very respectable Sussex clergy-
man, the associate of all the botanists of our younger days, and among
them the venerable James Dickson. He was a zealous promoter of the
study of natural history, though it is to be lamented he never pub-
lished on the subject. His parsonage, close to Withyham church,
was most beautifully situated, with a large piece of water in front
about a furlong below, on which it was delightful to see many of the
more rare species of birds sporting at liberty as if in their na-
tive haunts ; while others, still more domesticated, were strutting up
the house-steps and entering without fear to share with their kind
master the family repast. Behind rose an excellent garden, well
stocked with the scarcest plants, British and foreign, for botany was
his favourite pursuit."

The Very Rev. Henry Beeke, D.D., Dean of Bristol — A zealous
English botanist, and frequently quoted in the pages of " English
Botany."

Thomas Marquis of Bath, K.G., S^c.—k nobleman liberally dis-
posed to patronize the science of botany and to advance the interests

♦ See also Phil. Mag. and Annals, vol. x. p. 314.

Linneean Society, 465

of this Society. He was one of the most generous contributors to
the fund for the purchase of the Linnaean Collections.

Edward Turner Bennett, Esq., Sec. Zoological Society. — In allu-
ding to the death of Mr. Bennett 1 am strongly reminded of those
painful feelings with which the intelligence was first received; for
though his illness had excited alarm for a day or two in the minds of
some of his friends, and especially of those who were immediately
around him, it was generally unknown, so that the first intimation
which most of us received of it was that it had terminated fatally.
It was but a few days before that we had seen him in the enjoyment
of his usual health 3 and notwithstanding the apparent delicacy of his
constitution, from our having been accustomed to witness his un-
tiring devotion to his favourite pursuits, we had naturally been dis-
armed of all idea that his useful life was so soon to be brought to a
close. ^

I had not the honour of knowing him intimately, but it was im-
possible for any one who enjoyed even his casual acquaintance not to
be impressed with his intelligence, the gentleness of his manners, and
the unobtrusiveness of his character.

The cordial interest he took in his zoological studies, the kindness
and the intelligence he displayed in answering the inquiries of others,
his ardour in the promotion of zoology, the animated sense he had of
the moral and intellectual enjoyment to be derived from it, the abs-
ence of all unworthy rivalry in his character, and the affectionate
esteem he was held in by those who were intimately associated with
him in his pursuits, were ample proofs of his excellence, and of how
serious a loss we have sustained in him as the friend and the na-
turalist.

One of his intimate friends*, to whom I applied for some informa-
tion respecting his writings, says to me : "I can scarcely trust my-
self to speak of him in the terms that naturally present themselves
upon the recollection of all that was so good, so kind, and so talented
in his character. I believe I never knew a man in whom was com-
bined so much that was admirable and endearing. His duties as
Secretary to the Zoological Society were performed with such zeal,
talent, and extensive information as can never be forgotten by those
who had the opportunity of watching his labours and of acting with
him. His published works are not perhaps equivalent in importance
to his deservedly high character as a naturalist. His knowledge of
zoological literature was perhaps more extensive than that of any
other person in this country."

The only paper which Mr. Bennett communicated to the Transac-
tions of the Linnaean Society was ** A notice of a peculiar property
in a species of Echinus," which forms a nidus for itself by effecting a
cavity in rocks off the coast of Clare in Ireland. His contributions
to the Zoological Journal were numerous, and nearly all the analyses
of zoological works contained in it were made by him. The Proceed-
ings of the Zoological Society from their commencement, and the

* Thos. Bell, Esq., F.R.S.
Third Series. Vol. 10. No. G3. June 1837. 3 O

466 Lirmccaii Society.

first volume and the first part of the second volume of its Transac-
tions, were edited by him, and he contributed a great number of
scattered notices and many very valuable papers to them.

Of his separate works "The Tower Menagerie" appeared in 1829,
and " The Gardens and Menagerie of the Zoological Society" in
1830 and 1831, and an edition of ** White's Natural History of Sel-
bourne/' to which he added many interesting notes and illustrations,
was published soon alter his death.

These publications, the zealous discharge of the duties of secretary,
first of the Zoological Club of the Linnaean Society and afterwards of
the Zoological Society, with the more unobtrusive but not less use-
ful services which he rendered to zoologv by the advice and assistance
which he aflorded to all its cultivators who asked theni at his hands,
were his chief contributions to natural history. His intimate friends
are fully aware how large a portion of his time and how much pains
and labour be bestowed to the furtherance of the objects of others ;
and there are i'^w of the zoologists of this country who would not
bear testimony to the fact that by means of the assistance thus af-
forded he contributed to facilitate the progress of zoology in Great
Britain and to give it its proper direction. He died in his 40th
year, and has left behind him an enviable remembrance in the minds
of many amongst us whose scientific attainments and moral worth
deservedly place them high in our esteem.

Henry Thomas Colebrookey Esq., F R.S., 8ic., — one of the most di-
stinguished Oriental scholars of Europe, the successor of Sir William
Jones as Judge of the Native Court in Bengal and as President of
the Asiatic Society of Calcutta, and the founder of tiie Royal Asiatic
Society of London ; a man almost as eminent for his scientific ardour
as his high literary attainments.

Botany and geology were among the most favourite of his pur-
suits. He contributed three papers to our Transactions :

'* A description of select Indian Plants," in 1817.

" On the Indian Species oi' Menispermum,'* in 1819.

" On Bosvoellia and certain Indian Terehinihacece^"' in 1826.

Alexander Collie^ Esq., Surgeon R.N , — a native of Scotland and
beloved by all who knew him for the kindness of his disposition. He
accompanied Capt. Beechey on his voyage to Behring's Straits as
surgeon, and made valuable collections in natural history. He
went out with the first settlers to Swan River, and died at King
George's Sound in December 1835, bequeathing to the Linnsean
Society his collection of dried plants which he had made in that
colony.

Mr. Edward Donovan^ — author of various splendidly illustrated
works on the zoology of this country and on the insects of India and
New Holland. He wrote the articles Conchology and Entomology
in Rees's Encyclopaedia. His works perhaps exhibit more of the
splendour of art than of any enlarged views of science. He added
.some species to the previously existing knowledge of detailed zoology;
and it is painful to reflect that one who had laboured so much in the
cause of science should not have escaped the penury that too often
waits on age.

Anni7)ersary Notice of deceased Members. 467

John Latham^ M.D., F.R.S., 8fC., — one of the original members of
this Society, who for nearly half a century took the liveliest pleasure
in its prosperity and advancement.

This venerable and amiable man devoted himself to his favourite
science of ornithology with undiminished interest to the close of his
long life, which was extended to his ninety-sixth year. His writings
on ornithology were very voluminous and are essential to every stu-
dent ; for though his views are perhaps limited in some respects, com-
pared to those of more modern authorities, he made important use
of the labours of previous naturalists, and added many species to
those formerly known.

His great works are

" Index Ornithologic'us,'* in 2 vols. 4to, 1790; and *' A General Hi-
story of Birds," in 10 vols. 4to, 1821 — 1824.

He contributed three papers to our Transactions :

*' On the various species of Sawfish," in 1793.

•* Observations on the Spinning Limax," 1797.

•* Essay on the Tracheae of Birds," 1797-

It was a privilege of no ordinary kind to me, who had not attained
by several years even the moiety of the age of this venerable man,
to see him a few years ago, at our anniversary dinner, triumphant in
body and mind over the assaults of time ; and I remember looking
upon him with reverence, — not exclusively that becoming respect ever
due from youth to age, whatever may be its intellectual characteris-
tics, but that mingled feeling which partly arose from the impressive
consciousness that a life so protracted, and exhibiting so much calm
assurance of happiness, such serenity and cheerfulness of feeling, in
a scene from which so many of his early friends had gone for ever,
bespoke a mind at peace v.'ith itself and the world, and aftbrded a
lesson of what true enjoyment lies beyond even the Psalmist's limit
to the age of man, when time appears to have forgotten the good
man's claim to a better state of existence j and it was impossible not
to feel that his pursuits of natural history had perhaps contributed
largely to the complacency and the elasticity of his almost patriar-
chal age.

WiUiam Elfurd Leach, M.D., F.R.S. — Few men have ever de-
voted themselves to zoology with greater zeal than Dr. Leach, or
attained at an early period of life a higher reputation at home and
abroad as a profound naturalist. He was one of the most laborious
and successful as well as one of the most universal cultivators of
zoology which this country has ever produced.

His discoveries in the different classes of the Vertebrata, especially
Birds, were extensive ; but it was in Entomology and Malacology
that his labours have been most known and his improvements of the
greatest importance.

His knowledge of the Crustacea was superior to that of any other
naturalist of his time, and his arrangement the best until the work of
Dr. Milne Edwards appeared two years ago.

After a long suspension of his studies from ill health, during which
and up to the period of his death he was attended by the most de-

3 02

468 Linnaan Society,

voted of sisters, he returned to his favourite occupations with his ha-
bitual ardour, and the letters he wrote to his scientific friends in this
country exhibited the same devotion to the study of nature which di-
stinguished the brighter years of his life.

His principal work, ** The Natural History of the Molluscaof Great
Britain," in the possession of his friend Mr. Bell, is not yet pub-
lished. His other works were:

** Malacostraca Podophthalma Brita7inice,'' 4to, 1815 and 1816,
not finished.

*' Zoological Miscellany," 3 vols. 8vo, 1817.

"On the Genera and Species of Proboscideous Insects," 8 vo, 1817.

He described the animals taken by Cranch in the expedition of
Capt. Tuckey to the Congo; and was the author of valuable articles
in the Encyclopaedia Britannica, Edinburgh Encyclopaedia, Philoso-
phical Transactions, Zoological Journal, Memoirs of the Wernerian
Society, Dictionnaire des Sciences Naturelles.

Between 1810 and 1820 he contributed seven papers to the Trans-
actions of the Linncean Society : three on Insects j a general arrange-
ment of the Crustacea, Myriapoda, and Arachnides, a very laborious
work ; two descriptive of ten new genera of Bats ; one on three new
species of Glareola. He died in Italy last year of cholera.

General Joaquim Oliveira, — to whom we are indebted for the pre-
sent of the Flora Fluminensis of Vellozo ; a work illustrative of the
plants of Rio Janeiro. He held an important office under Don Pedro
in Brazil.

Joseph Sabine, Esq., F.R.S., 5fc. — Mr. Sabine at the time of his
death had been a Fellow of this Society for nearly forty years j and
as one of its friends who throughout his life devoted himself to the
pursuit of natural history there is a claim for justice due to his
memory.

He was the intimate associate of many of the oldest and most di-
stinguished of our Members, and there are some around me who un-
questionably must have looked on the unkindly feelings cherished
towards him of late years with deep regret, and who, without being
blind to the errors of judgement he may have committed, still feel
that those errors did not implicate his integrity, and that considering
his contributions to the stock of our knowledge in horticulture, bo-
tany, and zoology, and the kindliness of his nature in promoting the
interests of those whom he had it in his power to serve, the obliga-
tions of charity were lost sight of in the prejudices by which he was
assailed.

But his exertions in the cause of science should not be overlooked
nor undervalued; and any one who follows the progression in the de-
velopment of a more scientific system of horticulture in this country,
and an improved taste for the general cultivation of plants, will find
that his labours were productive of the best interests in this depart-
ment of science.

His zoological studies were principally directed to British ornitho-
logy, in which he was considered an excellent authority. He had
paid much attention to the changes of plumage in birds, to the time

lAnncEan Society. 469

of arrival and departure in the migratory species, and also to the
breeding and habits of domestic animals.

He published in the Transactions of the Linnaean Society a paper
on a new species of Gull from Greenland; and an account of the
Marmots of North America, with a description of three new species ;
and he wrote the Zoological Appendix to Capt. Franklin's Journey
of 1819— 1822.

He also contributed two papers on the Chrysanthemum Indicum of
Linnaeus, which he distinguished from what he has named the C. Si-
nense, the common plant of our gardens, imported into Europe in 1 789 ;
and there is a paper to appear in the forthcoming Part on the Rose
found by Sherard, a genus to which he had paid great attention.

A friend of his has furnished me with a list of forty papers which
he contributed to the Transactions of the Horticultural Society, and
these may surely be regarded as proofs of the iiiterest he took in its
objects and welfare.

I allude to his connexion with that Society with hesitation, because
I am ignorant on the subject j but I feel that the claims for justice to
the memory of Mr. Sabine will have greater weight, if there be no
disposition to conceal the acknowledged evils which arose from his
want of method in the management of its finances. Those evils,
their causes and effects, 1 unaffectedly regret, and I rejoice that they
have been remedied by the well-directed efforts of others ; and with
these acknowledgements I hope I may without impropriety quote the
charitable sentiments of one who has not been at all times sparing of
the literary deficiencies of his cotemporaries. Lord Jeffrey, in his
notice of Rogers's poem of Human Life, has this admirable passage,
which I think suited to the present occasion :

"When the inordinate hopes of youth, which provoke their own
disappointment, have been sobered down by longer experience and
more extended views ; when the keen contentions and eager rivalries
which employed our riper years have expired or been abandoned;
when we have seen year after year the objects of our fiercest hosti-
lity and of our fondest affections lie down together in the hallowed
peace of the gravej when ordinary pleasures and amusements begin
to be insipid, and the gay derision which seasoned them to appear
fiat and importunate ; when we reflect how often we have mourned
and been comforted, what opposite opinions we have successively
maintained and abandoned, to what inconsistent habits we have gra-
dually been formed, and how frequently the objects of our pride have
proved the sources of our shame ; we are naturally led to recur to
the days of our childhood, and to retrace the whole of our career and
that of our cotemporaries with feelings of far greater humility and
indulgence than those by which it had been accompanied j to think
all vain but affection and honour, the simplest and cheapest pleasures
the truest and most precious, and generosity of sentiment the only
mental superiority which ought either to be wished for or admired.'*
The Right Hon. Sir John Sinclair, Bart., F.ft.S.
Rev. George Henry Storie, M.A., of CamberweU,
Mr. White Watson, of Bakewell.

470 Linnaan Society.

The names on our Foreign list are those of ^fzelius, JussieUt Per-
sooriy and Schrader j men to whom I cannot affect to render even the
seml)lance of the respect due to them.

Adam AfzeliuSj Professor of Botany at Upsal, — was, I believe, the
last of the pupils of Linnaeus, and distinguished like all the pupils of
that great man for his exact botanical knowledge. He contributed
two papers to our Transactions : " On the Botanical History of Tri~
Jhlium alpestre, medium and pratense," in 1790^ and " Observations
on the Genus Pausus" in 1798.

He resided in Sierra Leone for several years, and published his
principal work, *' Genera Plantariim Guineensium," in 1804; and
several Dissertations on the medicinal plants of that country, and
some other works.

Antoine Laurent De Jussieu, Professor of Botany, Paris, — one of
the original Foreign Members of this Society, author of the " Genera
Plantarum secundum ordines naiurales disposita,'' and many papers in
the Annates and Mimoires du Museum d'riistoire Naturelle, in further
illustration of his views of the natural system.

The date of the publication of the " Gewe-ra Plantarum'"in 1789,with
the fact that the life of this illustrious man terminated at a very ad-
vanced age without a second edition of that great work, are proofs of
the great acquisitions made in botany within the last forty-five years,
and of the hopelessness, save from one individual, of the labours of
Jussieu being equalled by any single botanist.

I do not affect to speak of the merits or reputation of this eminent
man, but if there were any that can be claimed for him above even
the superiority of his intellect and learning, they were those of his
modesty and his entire freedom from undervaluing the labours of
others; and it is delightful to turn to a letter of his to Sir J. E. Smith
and to those of Bernard De Jussieu to Linnaeus, to observe hovir
purely these distinguished men regarded their mutual efforts to ad-
vance their favourite science.

Christian Henry Persoon, A.M. — The name of Persoon will live
as one of the highest classical authorities on the Fungi, for his Synopsis
Plantarum, published at Paris in 1805, and well characterized by its
motto " In parvo copia," though highly useful in its day, was natu-
rally doomed to be superseded by later works of a similar kind.

He contributed to our Transactions in 1799 a brief notice of a va-
riety of the Beech found near Gottingen, which he has termed Qwer-
coides, from the resemblance of its bark to that of the Oak.

He published between 1796 and 1800 some of his earlier works on
Fungi at Leipsic.and his " Synopsis Met hodica Fungorum" appeared at
Gottingen in 1801. This was followed by his ^^ Icones pictcB rariorum
Fungor urn, "' atV Sinn, \n ISO?), [xn^l\\t* ' Novce Species LAchenum"\x\ 181 1.
His collections were purchased by the King of Holland, and the
annuity he received for them contributed essentially to the comfort
of the later years of his life,

Henry Adolph Schrader, Professor of Botany, at Gottingen, — author
of the " Spicilegium Flora Germanic^'" in 1 794, and " Flora Germa-
nica,'' vol. ist, 1806, and various essays on Exotic Plants.

Geological Society. 47 1

His Flora Germanica has a high reputation, but it only extends
through the class Triandria. There is a very useful elaborate list of
the botanical writers of Germany at the commencement. The Flora
Britannka of Smith is s])oken of in Germany as inferior only to the
Flora Germanica of Schrader.

At the election which subsequently took place.

His Grace the Duke of Somerset was re-elected President; Ed-
ward Forster, Esq., Treasurer j Francis Boott, M.D., Secretary ; and
Richard Taylor, Esq., Under-Secretary ; and the following five gen-
tlemen were elected into the Council, in the room of others going
out, agreeably to the by-laws -.viz. Walter Buchanan, Esq. • William
S. MacLeay, Esq. ; the Lord Bishop of Norwich ; Richard Owen, Esq. j
and Henry F. S. Talbot, Esq.

(

GEOLOGICAL SOCIETY.

The regular order of our report of the proceedings of this Society
having necessarily been interrupted by the Anniversary Proceedings
of Feb. 1 7th, we now return to the papers which had been read pre-
viousl}' to that time, in continuation from p. 141.

Nov.30, 1836. — A paper "On certain elevated Hills of Gravel con-
tainingMarineShells in the vicinity of Dublin," by John Scouler, M.D.,
Professor of iVineralogy in the Royal Dublin Society, and communi-
cated by Robert Hutton, Esq., F.G.S., was first read.

The object of this communication is to give a brief account of phae-
nomena which, although frequently described in other countries, have
been but recently observed in Ireland. Before entering on the im-
mediate subject of the paper. Dr. Scouler gives a general description
of the formations constituting the district under examination. They
consist of granite, porphyry, quartz rock, micaceous, talcose, and
argillaceous schists, greywacke, which near Lyons is succeeded by a
very ferruginous conglomerate, and mountain limestone, called, near
Dublin, calp.

The principal points at which the author examined the shelly de-
posits are, the promontory of Howth, Bray Head, and the valley of
Glenismaule. On the south side of the promontory of Howth, where
the limestone or calp approaches the quartz rock, is a deep depression
occupied by an exceedingly tenacious and very ferruginous clay, which
also extends across the peninsula, filling up fissures in the limestone.
It is unstratified, and does not contain any transported fragments of
rocks, but abounds with nodules of oxide of iron, iron pyrites, and
oxide of manganese J the last being extracted for oeconomical pur-
poses. Resting upon this clay, the limestone and the quartz rock,
is a thick accumulation of shelly coarse gravel and fine sand, extend-
ing about half a mile in length, but separated into two parts by the
hollow in which is situated the village of Howth. The highest portion
of the deposit is about eighty feet above the level of the sea. The
gravel consists chiefly of limestone, differing in no respect from
the limestone of the district j pebbles of argillaceous schist are not
uncommon ; and rounded fragments of granite, the hard chalk of An-

4*72 Geological Society .

trim, iind flints occur, but rarely ; and it is worthy of remark that
though the gravel rests partly on quartz rock, fragments derived from
it are scarce.

The beds of sand are sometimes very thin, at others of considerable
thickness, and tliough, for limited distances, there appears to be a
regular stratification, yet the beds cannot be traced to any extent,
thinning out in the same manner as on existing sea-beaches. The
shells which have been Found were, for the greater part, very imper-
fect, but Dr. Scouler has been enabled to determine, from well-defined
specimens, the following species : Turritella ungulina, Turbo lito-
reus, Nerita Utoralisy Buccinum undatum, Cardium edule, Cyprina
Islandka, and Pecten varians.

On the opposite side of the Bay of Dublin, and to the south of the
promontory of Bray Head, is a similar accumulation extending for
upwards of a mile. At its northern extremity it presents a perpendi-
cular section about 200 feet high, but gradually declines towards the
south till it sinks to a level with the present shore. It consists, in the
upper part, of angular fragments of granite or syenite, and quartz
rock J in the middle, of numerous beds of shelly sand and gravel, and
in the lowest, of clay and marl. The central beds of gravel are chiefly
composed of fragments of limestone of moderate size, and imperfectly
rounded, but they also contain pebbles of chalcedony, flint, hard
rhalk, and a ferruginous conglomerate. With respect to the locali-
ties from which these materials were derived. Dr. Scouler says, that no
limestone occurs in situ nearer than the opposite side of the Dublin
granitic mountains j that the fragments of chalcedony, flint, and hard
chalk, appear to have been transported from Antrim, and the pebbles
of ferruginous conglomerate from Lambay Island, or Lyons Hill,
to the west of the Dublin chain. The whole of the recent species of
shells found at Howth, have been obtained at Bray Head, with the
addition of Dentalium entails.

Besides these shelly deposits which occur adjacent to the existing
sea shores. Dr. Scouler describes others at a considerable distance
inland. One of the most remarkable of these, is in the valley of Glenis-
raaule, near the source of one of the branches of the Dodder, and
about seven miles from the Bay of Dublin. On each side of the
valley are perpendicular clifl^s formed of irregular beds of sand and
calcareous gravel, about 100 feet thick, and probably 200 feet above
the level of the sea. These beds are also above the level of any of
the calcareous strata of the immediate neighbourhood. Associated
withthelimestonefragmentsare pebbles of flintandchalcedony, as well
as recent shells identical with those in the beds previously described
at Howth and Bray Head. Dr. Scouler also mentions having found
a specimen of limestone perforated by Lymnoria terebrans. Similar
deposits are stated to exist in other valleys in the vicinity of Dublin;
and accumulations of gravel, agreeing in the arrangement of the beds
but difl^ering locally in the nature of the materials, to extend over the
whole of Ireland, forming low rounded hills, and filling previously
existing depressions.

The only instance of remains of mammalia in this gravel, known to

Geological Society, 473

Dr. Scouler, is the discovery of bones of the Irish Elk, at EnnisHerry,
near Dublin.

The following inferences were then given, as deducible from the
facts contained in the memoir :

1st, That the coast around the Bay of Dublin has been elevated,
though unequally, at a comparatively recent geological epoch ; 2ndly,
That the vallev of Glenismaule, and other valleys containing similar
accumulations of drift, were at onetime under water, and then filled
with calcareous gravel ; and that they were afterwards elevated, and
subsequently re-excavated by the action of running water.

The memoir concluded with some theoretical observations respect-
ing the sources from which the calcareous gravel was derived, and
the agents by which it was brought into its present position.

A paper *' On the Geology of the Thracian Bosphorus," by Hugh
Edwin Strickland,Esq.,F.G.S., and William John Hamilton, Sec. G.S.,
was then read*.

The formations which occur in the neighbourhood of the Bosphorus
may be classed as follows : 1. A series of beds considered to be equi-
valents of part of the Silurian system ; 2. Igneous rocks ; 3. Tertiary
limestone ; 4. Ancient alluvium.

1. The equivalents of the Silurian system occupy both sides of the
Bosphorus for about three quarters of its length, and extend in Eu-
rope and Asia towards the W.N.W. and E.S.E. to an unascertained
distance. The prevailing rock is argillaceous schist, but associated
with it are compact brown sandstone, and compact dark blue lime-
stone, the whole passing insensibly into each other. Andreossy
and an American traveller referred the deposits to the transition
class, on mineralogical characters ; and the authors of this memoir,
to that portion of it lately named Silurian by Mr. Murchison, from
the general agreement of the organic remains to those found in the
formations beneath the old red sandstone in England. Fossils are,
however, of so rare occurrence that Messrs. Strickland and Hamilton
noticed them at only two localities, a ravine above Arnaout-keui, about
four miles from Pera on the European side ; and the Giant's Moun-
tain on the Asiatic side of the Bosphorus, and about fifteen miles from
Constantinople. At the former locality they were found in argilla-
ceous schist, and in the latter in limestone. They belonged chiefly to
the genera Spirifer, Productus, Terehratula, Atrypa and Orthis ; but
the eye of an Asaphus, remains of Crinoidea, and of three genera of
Corals were also obtained.

2. Igneous Rocks. — The transition rocks are united on the north to a
mass of igneous rocks, and on the south-west to tertiary deposits.
The authors were unable to determine the relative age of these two
formations j but as the igneous rocks are brought into more immediate
connexion with the Silurian or transition group than the tertiary, they
are described first. They consist of trachytes and trachytic con-

* In a note, Mr. Strickland says, that Mr. Haniilton being still in Asia
Minor, he hfls been deprived of any direct assistance in drawing up this
paper ; and that he is solely responsible for any theoretical views which it
mav contain.

Third Series. Vol 10. No. 63. June 1837. 3 P

474« Geological Society.

glomerates. The former are more or less compact, sometimes passing
into phonolite and basalt, and occasionally assume a columnar struc-
ture. The conglomerates are composed of angular fragments of tra-
chyte, imbedded in a tufaceous paste. The inclosed portions are some-
times softer than the cement, when the rock assumes a honeycomb
appearance, but they are more often harder, and stand out in bold
relief. The conglomerates rest upon and alternate with the trachyte,
and in some places are intersected by basaltic dykes. Veins of car-
nelian and chalcedony are stated to be contained in the igneous rocks,
and near Filbornou to pass through the conglomerate, traversing both
the basis and the included fragments. These conglomerates are
considered by Mr. Strickland to have been accumulated by water, and
the contained fragments, though commonly angular, are sometimes
rounded, and included in finely laminated volcanic sand. On the
Asiatic side of the Bosphorus the igneous rocks commence en masse
at Kavak, under the old Genoese Castle, and extend to Yoom-bornou
on the Black Sea, or perhaps further 3 and on the European side they
commence on the north of Buyukder6, and also extend to the Black
Sea. Besides these great masses of igneous products, trachytic and
trap dykes were observed by the authors traversing the Silurian rocks
at Baltalimani, in the hills above Bebek, at Kiretch-bornou, and the
base of the Giant's Mountain.

3. The Tertiary deposit commences -immediately on the west of
Constantinople, and extends inland about three miles, till it meets the
transition formations, and ranges along the north coast of the Sea of
Marmora for many miles, its western limit being at present undefined.
Id is best exhibited in the quarries at Baloukli and Makri-kuei, where
it consists of horizontal beds of soft, white, shelly limestones and marls,
resting on sand in which no fossils have been observed. Near Con-
stantinople the deposit was apparently accumulated in an aestuary,
for it contains a species of Cardium, and considerable numbers of a
fossil considered to be a Cytherea, the whole being associated with
land and freshwater shells, some of which resemble recent species.

Along the banks of the Bosphorus the authors observed no traces
of a tertiary formation ; and consequently infer that this channel was
opened at a comparatively very recent period.

The only ancient alluvium mentioned in the memoir is an extensive
and thick deposit of ferruginous clay, sand, gravel and boulders, rest-
ing upon the Silurian or transition rocks. It commences a few miles
north of Constantinople, forms the subsoil of the Forest of Belgrade,
and apparently skirts the southern side of the Lesser Balcan range.

Dec. 14.— A paper "On Impressions in Sandstone resembling those
of horses' hoofs," by Charles Babbage, Esq., and communicated by
the President, was first read.

During a recent visit to Dowlais, Mr. Guest mentioned to the
author, that in the channel of a stream on the extensive moor
called Fwll y Duon, and about seven miles from Merthyr Tydvil,
there were many impressions considered by the country people to
have been made by horses' hoofs. The stratum of sandstone in which
they occur is called the Farewell Rock, being the lowest bed of the

Geological Society, 475

coal measures. At first sight they presented a strong resemblance to
the marks which the hoof of a horse would leave on a soft surface, but
on a closer examination Mr. Babbage found that the part which should
have received an indentation from the frog was in relief, and resem-
bled rather a cast of the frog itself. The first mark examined by him
proved to be the letter G, which had been carved on the rock by some
person whose initials were G. H. This discovery made him inspect
the others more minutely, and he ascertained satisfactorily that they
were not artificial. Similar impressions were noticed by him at several
places on the moor.

The author then referred to analogous casts in the old red sandstone
of Forfarshire, and there called Kelpies' feet.

In attempting to account for the marks, Mr. Babbage described
some observations recently made by Mr. Lyell on impressions left by
Medusae on the rippled sand near Dundee. On removing the gela-
tinous body of the animal, a circular space was exposed, not rippled,
but having around half the border a depression of a horse-shoe form.
These marks, however, were not considered by Mr. Lyell as identical
with those called Kelpies' feet, but merely so far analogous as to in-
vite further observations, and to make it desirable to possess drawings
of the impressions which different species of Medusae leave, when
thrown by the tide upon a beach of soft mud or sand.

A memoir *' On the occurrence of silicified trunks of large trees in
the new red sandstone formation or Poikilitic series, at Allesley, near
Coventry," by the Rev. Wm. Buckland, D.D,, Professor of Geology
and Mineralogy in the University of Oxford, was then read.

In the great bed of gravel which overspreads the portion of War-
wickshire referred to in this paper, specimens of silicified wood had
been long found, and from being slightly rolled, it was conjectured
that they could not have been drifted from a distance, though no in-
dication of their original matrix had been observed. In the spring
of last year, however. Dr. Buckland was informed by the Rev. VV. T.
Bree of Allesley, that part of the silicified trunk of a tree, several feet
in length and a foot and a half in diameter, had been discovered in the
garden of the Rev. Mr. Gibson, at the bottom of Allesley Hill. On
visiting the spot in October last, the author ascertained that the
tree was not imbedded in the gravel, but in that portion of the new
red sandstone series, which consists of indurated sandstone, alterna-
ting with beds of conglomerate, chiefly made iip of sand and of peb-
bles of quartzite and compact forms of trap.

In the churchyard of Allesley Dr. Buckland found an angular frag-
ment of similar silicified wood which had been fresh cast up from the
bottom of a grave, sunk to an unusual depth in the red sandstone ;
and in making a road from Allesley towards Coventry another large
tree was discovered a short time ago, and the greater part of it used
in forming the foundation of the road. On comparing the fragments
found in the gravel with the tree in Mr. Gibson's garden, which is
carefully preserved in its matrix, Dr. Buckland found so perfect an
identity in mineral character as to leave no doubt that the fragments
in the surface gravel had been derived from denuded beds of the new
red sandstone.

3 P2

476 Geological Society.

A description was then given of the mineralized condition of the wood ,
and its organic structure. On the surface of many of the specimens
from the gravel, is a multitude of small spherical cavities, each of which
was once filled with a minute round concretion of oxide of iron or im-
perfect jasper j and innumerable specks formed by these concretions
pervading the interior of the specimens, appear to have been formed
in a manner analogous to that which produced the eye agates in the An-
tigua wood. The tree in Mr. Gibson's garden, and many of the larger
fragments found in the gravel, abound with minute longitudinal
apertures resembling those in shrunk and shaken timber; many of
these are filled with red oxide of iron, or lined with beautiful crystals
of dark-coloured quartz. In two specimens Dr. BuckUmd noticed lon-
gitudinal holes about ^th of an inch in diameter, which had apparent-
ly been perforated by the larvae of some insect. In the large collection
formed by Mr. Bree, the author sought in vain for examples of the
petrified palms, psarohtes and helmintolites described by Cotta and
Sprengel as found in Saxony, in beds considered to be the equivalents
of the new red sandstone of England j all the Allesley specimens are
either referrible to decided coniferae, which have distinct concentric
lines of growth, or exhibit a compact structure in which neither large
vascular tubes nor concentric lines of growth are visible.

A paper entitled ** Further notice on a partially petrified piece of
wood from an ancient Roman aqueduct at Eilsen, in the Principality
of Lippe-Biickeberg," by Charles Stokes, Esq., F.G.S., was next
read.

Since his former communication on this subject, (Lond. and Edinb.
Phil. Mag. vol. ix. p. 499) the author has been shown by Mr. Robert
Brown a specimen from the same partially petrified piece of wood ;
and Mr. Brown has pointed out to him, in its longitudinal section,
that the petrified portions are spindle-shaped bodies, about two inches
in length, in some instances completely inclosed within and sur-
rounded by the unchanged wood, and are not, tlierefore, as formerly
conjectured by the author, connected by such an external supply of
carbonate of lime to particular points as might have been derived from
stalactites formed in the building.

Tne author also stated that Mr. Brown had called his attention to
the remarkable circumstance exhibited in this specimen, that though
the change in the longitudinal fibres appears to be complete, yet the
medullary rays are still in their ligneous state ; and on referring to
the specimen formeily described, Mr. Stokes has found some instances
in which a part of the medullary ray which passes through the petri-
fied portion has not been so completely changed as the surrounding
longitudinal fibres, or the part of the same ray which is more in the
centre of the petrified portion.

Of the unpetrified part of the specimen, some portions are much de-
cayed and worm-eaten, while others are hard and apparently in good
preservation; the line of separation between the two conditions being
occasionally remarkably well defined. On submitting portions of
each to the action of muriatic acid, Mr. Stokes found that the decayed
part exhibited only a slight effervescence, while that which appeared
in good preservation gave oflf a much greater quantity of gas, and

Geological Society, 477

chiefly from Ihe inside of the larger vessels, as if they were coated
with an extremely thin layer of carbonate of lime. This fact, connected
with the medullary rays remaining in some instances unchanged, orbut
partially changed, presents, as stated by the author, the first ocular
demonstration of progressive steps in the process of petrifaction. The
communication concluded with some observations on the fossil wood
of Allesley described in Dr. Buckland's paper, in some of the specimens
of which there are spindle-shaped portions similar to those in the
partially petrified wood of Buckeberg.

** Description of a Raised Beach in Barnstaple Bay, on the north-
west coast of Devonshire," by the Rev. Professor Sedgwick, F.G.S.,
and Roderick Impey Murchison, Esq., F.G.S., was afterwards read.

This raised beach is first seen at the northern extremity of the
blown sand-hills called Braunton Burrows, and thence may be traced
round the western end of Saunton Down, into Croyde Bay. i^fter
meeting with some interruptions it reappears, and may be followed to
the face of the bold headland called Baggy Point, about three miles
from the place of its commencement. In situations where it is best
exposed, especially on the south side of Saunton Down, it puts on
the form of a horizontal under terrace, resting upon an indented
and irregular surface of the older formations, and abutting against
their component beds. It forms regular sea-cliffs, the stratification of
which is most distinct ; and the several beds may be traced by small
bands of shingles, by alternating courses of different degrees of fine-
ness, and by horizontal lines of division. In distinctness of stratifica-
tion it yields to no rock 3 and as several parts of the cliff are in a state
of perfect induration, presenting regularly bedded masses of calcareous
grit and sandstone, the authors at first sight mistook it for a secondary
formation.

The bottom of this horizontal deposit is chiefly composed of indu-
rated shingles resting on the ledges of the older rocks, and filling
up their inequalities. These conglomerates or shingles are seldom
of great thickness, but in some places alternate two or three times
with beds of sand, so as to reach an elevation of eight or nine feet in
the horizontal deposit. Over the shingles are horizontal beds of sand,
occasionally indurated, sometimes putting on a concretionary struc-
ture, and weathering into grotesque forms by the action of the ele-
ments. Lastly, the preceding deposits are surmounted by regular
beds of finely laminated sand in a state of imperfect induration, and
sometimes hardly differing from the sand of the actual beach between
the high and low water marks. The thickness of these beds of sand
amounts in some places to more than twenty feet. These marine
deposits are frequently covered by terrestrial overshot materials which
have descended from the higher talus of Saunton Downs. In the
whole of the stratified under clift' above described there are sea shells.
In the upper part they are rare, and in a bad state of peservation j
but in the lower and more indurated portions they are more abundant,
are often well preserved, sometimes appearing in beds, and in their
condition and arrangement exactly resembling the shells of a modern
beach. In species, they are identical with the living shells of the coast.

478 Geological Society.

Among therTi the authors enumerate Mactra stultorum, Tellinafa~
bula, T. soliclula,Caidium edule, Ostrea edulis, Mytllus edulis, Mya
margaritacea, Pholas, Patella vulgaris, Nat'wa canrena, Purpura
lapillus, <^c., making in all twelve or fourteen species*.

At the north side of Croyde Bay the sea shells are very abundant
in the deposit j the lower shingles expand to the thickness of nineteen
feet, and are Ibund on the face of Baggy Point at various heights and
rising to sixty or seventy feet above high water level.

The horizontal beds, above described, cannot have been formed by
accumulations of blown sand. They are stratified marine deposits,
dilfering in no respect from the sand and coarsest shingles of the
neighbouring beach, except in the level j and they perfectly demon-
strate an elevation of the neighbouring coast during the modern period.

In confirmation of their views, the authors assert that the physical
features of the neighbouring region, indicate that kind of depression
in the sea level which is demonstrated by the raised beach. The
ancient line of sea-cliffs m;<y be traced inland by Saunton and Braun-
ton towards the mouth of the Barnstaple river, passing to the east of
the existing marshes and dunes of blown sand. In like manner the
old line of cliff's, anterior to the elevation, maybe traced from Apple-
dore along the south side of Norton Burrows. The popple or pebble
beach, a remarkable ridge of large rounded blocks of stone, rising to a
height of seventeen feet above the sea level, and shutting out the
ocean from the neighbouring marsh lands, &c., of Appledore, is, in
connexion with tlM? blown sands, regarded by the authors as the
natural and necessary consequence of a considerable elevation of the
coast, and as strongly confirming the views they have advanced. In
further support of these views, they state that the raised beach of
Barnstaple Bay, forms only one of a connected series of phaenomena,
all tending to demonstrate the same conclusion, viz. the occasional
changes of high water level, both in the way of elevation and depres-
sion, within a comparatively recent period. They point out the
conditions under which raised beaches (admitting their hypothesis)
may or may not be expected ; and they affirm that there is a con-
nected series of phenomena both on the north and south coasts of
Devonshire and Cornwall, in perfect accordance with what they have
described. The raised beach of Hope's Nose is the most striking in-
stance in South Devon ; and they bear witness to the correctness of
Mr. Austen'sdescriptionof it, and to the justice of hisconclusions. On
the coasts of Cornwall phaenomena of like kind are very numerous.
Not only is there incontrovertible proof of raised beaches at various
levels, but in some places long smooth waterworn surfaces, exactly
like those formed by the existing breakers of a rocky shore, may

* This list has beon much augmented by the subsequent labours of Ma-
jor W. Harding,F.G.S.of Ilfiacoinb, whohas in other respects contirmed the
views of the authors, and added sonje important facts. In the craggy cliffs
of the old transition rocks near Baggy Point, he has detected patches of the'
indurated shingle, or *' dry beach" as he terms it, containing modern sea
ihellsat dij^e rent heights, far above the reach of the highest tides.

Zoological Society, 479

be traced midway in the cliff, at an elevation quite out of the reach
of the cause which formed them.

Lastly, the authors enter on some details as to the quantity of ele-
vation, proved by the phaenomena of recent marine deposits in differ-
ent parts of England. They state that the raised beaches of South
Devon and Cornwall indicate various changes of level, from ten to
forty feet, the phaenomena of depression, of which there are examples,
not being considered. That the greatest elevation in North Devon
seems to have been about 70 feet, while in Lancashire, Cheshire, and
Shropshire, there are murine deposits, containing also shells of existing
species, at various elevations of from 300 to 500 feet. The intensity
of elev.itory force seems therefore to have increased towards the north,
and perhaps reached its maximum among the Cumbrian mountains,
from which enormous masses of materials have drifted in various well-
known directions.

The country of Siluria and South Wales, the detritus of which was
described by t\lr. Murchison on a former occasion, is of course spe-
cially exempted from the application of this inference j since that re-
gion has been shown to have been elevated at an antecedent period*.

On the same evening, after the ordinary business of the Society
had terminated, a Special General Meetingbeingheld for the purpose of
electing two Secretaries in the place of William John Hamilton, Esq.,
and Woodbine Parish, jun. Esq., who had retired from the office, the
scrutineers reported that Robert Hutton,Esq., and John Forbes Royle^
M.D. F.L.S., were duly elected.

ZOOLOGICAL SOCIETY.
(Continued from p. 300.)

November 8, 1836. — A letter, addressed to the Secretary, by Ro-
bert Mackay, Esq., the British Vice-Consul at Maracaibo, and a Cor-
responding Member of the Society, was read, describing the habits
of a Vulture {Vultur Papa, Linn.) forwarded to the Society for the
Menagerie, hut which had unfortunately died during the voyage.

After noticing the peculiar habit attributed to these birds, (which
frequently congregate to the number of three hundred,) of paying
deference to an individual differing from the rest in plumage, and
to which the inhabitants of Maracaibo give the title of king, Mr. Mac-
kay proceeds to scate :

" These birds, in their flights, ascend to such a height as to be
lost sight of, and from their elevation, discover objects of prey.

" They reside in the savannas of a warm and dry temperature ;
and their travels do not extend beyond five or six leagues of the
place where they have been bred.

" They lay their eggs, and hatch their young, in the small con-
cavities of mountains.

" At a distance from towns, villages, and frequented roads, they

* Geol. Proceedings, Vol. IL p. 77; or Lond. and Edinb. Phil. Mag,
vol. viii. p. 566.

480 Zoological Society.

generally assemble in large numbers; but in the immediate vicinity of
such situations the king never deigns to associate with his vassals."

At the request of the Chairman, Mr. W. Martin read the follow-
ing description of a new species of the genus Felis.

"The beautiful species oi Felis to which I beg leave to call the
attention of the Meeting was brought from Java or Sumatra, and
obtained, with other specimens from the same locality, from Mr.
Gould. The only writer, as far as I can learn, who notices it, is
Sir W. Jardine in the ' Naturalist's Library,' in which work are two
figures from specimens in the Edinburgh Museum; but he there
confounds it with the Felis Diardi of Cuvier, to which species, as
indeed also to the Felis Bengalensis, it bears a close affinity in the
style and colour of its markings. It will be easy, however, to show
that the Felis Diardi is a very different species to the present. The
first description of the jP. Diardi is in the fourth volume of Cuvier's
Ossemens Fossihs, p. 437. 'There is,' says Cuvier, 'in Java an-
other wild Cat larger than Felis Bengalensis, very remarkable for the
beautiful regularity of its blotches, of which Messrs. Diard and Du-
vaucel have transmitted to us a skin and a drawing. We shall de-
signate it Felis Diardi' After describing its colour, he adds, * The
head is six inches, the tail 2 feet 4 inches, the body 2 feet and a
half, and its height at the shoulder must be 18 inches.' (French mea-
sures.) With regard to the Felis Diardi, it is somewhat questionable
whether it be distinct from the Felis macrocelis, or not ; at all events
it is a large Cat closely allied to, if not identical with that animal,
but certainly distinct from the Cat before the Meeting.
" The admeasurements of this species are as follows :

Feet. Inches.

Head and body 1 11

Head from nose to occiput, following 1 q t-i

the arch of the skull j ^

Tail 1 3|

Height at shoulder 0 10^

Total length 3 2-i

*' It may be observed, that the individual is adult, as proved by
the state of the dentition; its colouring agrees closely with that de-
tailed by Sir W. Jardine. The ground tint is rusty grey the rufous
tinge prevailing on the top of the head down the middle of the back,
over the cheeks, chest, scapulse, fore limbs, and thighs. On the top
of the head are two longitudinal markings of black inclosing a space
cut up by irregular small rings or dashes of black, and external to
these begin two decided black lines (commencing over each eye),
which become broader on the occiput and back of the neck, on
which latter part they converge, but do not come in contact with
each other; they then sweep over the top of each shoulder, blending
with the markings of the body.

" Continued from the first-described central markings on the head,
there runs between these two decided stripes a broken line, as-
suming between the shoulders the form of elongated open spots, and

Zoological Society, 481

ultimately a black dorsal stripe continued to the base of the tail ;
on the haunches, however, it divides into two parallel stripes. The
ears are short and somewhat rounded, black at the tips, grey in the
centre, and black at and around their base ; beyond the black mark
at their base, there is a space of dusky grey, which merges into the
colour of the neck. The sides of the neck, scapulae, fore and hind
limbs, are thickly spotted with black. The sides of the body are
marbled with obliquely longitudinal marks of dark grey, each mark
having an irregular margin of black.

" The lower angle of each eye is black, and two black lines cross
the cheek, passing into a throat-mark carried across beneath the
angle of the lower jaw; below this is a similar mark but more in-
definite ; the chest is spotted with black. ITie abdomen is dirty white
which is crossed by rows of black spots in regular order. The upper
surface of the tail is grey, the lower yellowish grey ; it is marbled
by spots of black forming indistinct rings, which, towards the tip,
assume a more definite character; the extremity being black. Tlie
fur of the body is moderate and sleek; on the tail it is full and soft.

" For this beautiful species of Cat I venture to propose the title of
Felis marmorata. Though inferior in size to the Felis macroceliSt
this species is related to it, not only in the style of the markings
of the fur, but in the elongation of its form, and the length and
thickness of the tail; it is a Rimau Day an in miniature; nor, though
larger than the Felis Bengalensis, is it less allied to that species, be-
tween which and the former it constitutes an intermediate grade."

November 22, 1836. — A communication from Mr. Harvey, of
Teignmouth, in Devonshire, was read, which referred to a specimen
of the electric Ray then on the table. The fish was caught in a trawl-
net near Teignmouth, and was presented to the Society by Mr.
Harvey. When taken, part of a specimen of the small spotted Dog-
fish was hanging from its mouth. The fishermen handle the electric
Ray while it is alive without being at all affected by it, always
taking care to lay hold of the tail.

Mr. Yarrell exhibited a very large Carp tak^n by a net in a piece
of water called the Mere, neare Payne's Hill, in Surrey. The length
of the specimen was 30 inches, the girth of the body at the com-
mencement of the dorsal fin 24 inches; the weight, 22 pounds. The
fish belonged to Edward Jesse, Esq., author of the " Gleanings in
Natural History," by whose permission it was exhibited. Mr. Yar-
rell observed, that he could find no record of any Carp so large
having before been taken in this country.

Mr. Martin, at the request of the Chairman, read the following
notes on the anatomy of Koala, Phascolarctos fuscus, Desm.

" The acquisition of a young male Koala preserved in spirits, and
presented to the Society by Captain Mallard, has aflforded me the
opportunity of examining the viscera of this rare and curious animal ;
which I did with the utmost care. Differing from the Wombat in
its dental formula, in which respect it closely resembles the Kanga-
roos, the visceral anatomy of the Koala closely approximates to that
of the former animal, as will be perceived by comparing the foUow-
Third Series, Vol. 10. No. 63. June 1837. 3 Q

482 Zoological Society,

ing notes with the description of the anatomy of the Wombat by
Mr. Owen.

" On reflecting the skin of the abdomen, there appeared a small
transverse muscle arising from the skin on either side, which passed
over the marsupial hones, towards their upper extremity, acting as
a support to, and a compressor of them.

"The pyramidalis muscle, to which, on its outer side is attached
the inner edge of the marsupial bone, radiated from this bone to the
middle line, and sent off a broad/asm of fibres over the rectus mus-
cle to the cartilages of the ribs. The rectus began broad from the
cartilages of the lower ribs, its fibres appearing to mix with those of
the pectoralis; it continued its course broad to the pubis, and was
inserted in the usual manner. The external oblique was thick and
its fibres remarkably strong ; the internal oblique gave off a strong
cremaster, which ran down the spermatic cord as far as the testis.

*' The transversalis as usual.

" The first head of the triceps adductor femor is was connected by
a slip of fibres to the external apex of the triangular base of the
marsupial bone, giving to that bone, by its contraction, a slight ex-
ternal motion.

" The panniculus carnosus was very strong, especially over the
back and sides.

" Tlie capacity of the thorax was very small m comparison with
that of the abdomen.

" The stomach occupied the left side of the abdominal cavity,
scarcely passing the mesial line ; its pyloric portion bent down
abruptly, forming a narrow arch through which protruded the /o-
bulus Spigelii of the liver.

" The liver consisted of two equal parts, a right and left, both
closely attached by membranous (or peritoneal) processes to the
diaphragm; the lig amentum latum verged towards the left side. The
right portion of the liver was divided into three foliaceous lobes, the
left into two : the free edges of this viscus were deeply and abruptly
fissured, as if cut with a knife ; and its under surface presented an
irregular congeries of small lobuli or appendages, clustered thickly
together ; on the left side, the outer lobe of the liver passed com-
pletely behind or dorsad of the stomach, the cardiac portion of which
advanced as low as the left kidney. The outer lobe of the liver on
the right side advanced in a pointed form, and passed behind the
whole of the dorsal surface of the right kidney. The great mass
of the liver had, in fact, a dorsad position, the anterior portion being
comparatively very trifling.

•• The gall-bladder was seated in the fissure between the first and
second lobes, reckoning from the right side ; it was very large, but
empty. Of great width at its base, it narrowed gradually to an al-
most vermiform apex, and its total length was 3| inches. Its duct,
of considerable calibre, terminated exactly one inch below the py-
lorus.

*' The spleen was long, thin, and tongue-shaped ; it lay loosely
adhering to the cardium ; its greatest breadth was ^ an inch, its

Zoological Society, 4^f

length, 2 1 inches; its edges were very thin and slightly crenu-
lated.

" The pancreas presented a thin, flat portion, attached to the
spleen, whence ran a broad slip attached to the peritoneal reflection
at the back of the stomach, and advancing round to the duodenum.
Its duct joined that of the gall-bladder I of an inch from its inser-
tion.

" The stomach was divided by a contraction, into two distinct
portions ; of these, the cardiac was large and almost globular, its
breadth across being 2, its length across 2^ inches; Itsparietes were
much thinner than those of the pyloric portion, which, as we stated,
bent down abruptly, so as to form a narrow arch. The breadth of
the pylorus at its commencement, was little more than an inch, but
it swelled out into a sacculus, whence it narrowed to the pyloric
orifice. Following its greater curve it measured 2J inches, along
its smaller, only | of an inch. It was slightly puckered transversely
on the sides by a posterior longitudinal band of fibres. Anterior to
the entrance of the oesophagus, and occupying the space of the smaller
curvature of the stomach, between the oesophagus and the contraction,
was situated a large thick gland, opening by numerous ducts, whose
mouths clustered together, formed a sort of network. On each side
of this gland the inner membrane of the stomach was longitudinally
corrugated with small ruga, whence larger j9/fc«, and more distinct
from each other, were continued down the inner surface of the py-
lorus, to its orifice, which was closed with a strong sphincter-valve;
the cardiac pouch was lined with a thin smooth cuticular membrane.
The duodenum began pyriform with a small sacculus | of an inch in
breadth, whence it narrowed to ^ of an inch; this being its average
breadth. Its course was as follows: Leaving the joy/orw5, and bound
to the spine by mesentery, it advanced over the right kidney, then
crossed the spine, turned up on the left side under the cardiac portion
of the stomach, and merged into jejunum. The whole of the inner
membrane of the small intestines exhibited a beaiitiful velvety tissue.
" The caecum was of enormous magnitude, and slightly puckered
equidistantly or nearly so throughout its whole length into sacculi,
by a slight longitudinal (mesenteric) band of muscular fibres ; there
appeared also faint traces of an opposite band. Turning spirally
on itself and beginning large, it gradually narrowed, the decrease
of its last portion, for the length of 18 inches, being very marked ;
this portion running to a long vermiform point. The total length
of the caecum was 4 feet 2 inches. Basal breadth, 2 inches. The
colon, resembling in character the first portion of the caecum, was
slightly contracted into large sacculi, the first sacculus just below
the entrance of the ileum, being more decided and larger than those
which succeed ; it was, however, nothing more than a simple en-
largement, without any pyramid figure. After a course of 17 inches,
the colon decreased in size to the breadth of § of an inch ; the total
length of the large intestines was 6 feet 4 inches. The inner mem-
brane of the rectum was corrugated longitudinally.

'* The lungs consisted of 3 right lobes, one lai-ge, and two small ;.
and of two left lobes, the lower bv far the largest.

3'Q 2

^

484 Zoological Society,

**The heart was compressed and pointed; its length was two
inches.

" The aorta gave off as usual 3 branches for the supply of the an-
terior portion of the body. The first or arteria Innominata, however,
almost immediately divided into carotid and subclavian. The right
auricle presented at its upper part a semilunar notch fitting to the
base of the aorta, two points rising up, one on each side of the aorta,
as auricular appendages. Into the upper part of the auricle just be-
hind the right appendix entered the right vena cava superior ; and
into the inferior portion of the auricle close to the entrance of the
vena cava inferior, entered the left vena cava superior. The vena
azygos running up on the left side of the aorta, entered the left vena
cava superior an inch from its termination. This arrangement of
the vence cavce appears to be normal in the Marsupials, as Mr. Owen
has previously observed.

*' Six coronary veins entered the right auricle round its junctional
margin with the ventricle.

*• The auriculo-ventricular opening on the right was of moderate
size, with a simple valve, the edges of which were bound down by
the tendons of two distinct carnece columna ; a third fasciculus of
fleshy fibres, but very indistinct, were to the right of these, but they
could hardly be said to constitute a third carnea columna. The
right ventricle does not approach the apex of the heart by ^ of an
inch. No trace of foramen ovale. Pulmonary artery very wide,
dividing after a course of ^ an inch in two branches, a right and
left. Right ventricle very thin ; the left, very thick and firm.

" Of the kidneys, the right was seated higher, nearly by its whole
length, than the left ; the lower end of the former and the upper end
of the latter being parallel. In shape, these organs were oval, and
but slightly compressed. Their pelvis was small, the papilla single
and obtuse; the cortical and cineritious layers very distinct. Length,
1 J of an inch ; breadth, f of an inch.

"The penis, of small size and conical figure, was placed imme-
diately anterior to the anus ; it was slightly bifurcate, or rather had
two projecting papillte, one on each side of the urethral orifice.
Length of spongy portion, | of an inch. Bladder small, oval, and
much contracted. Testis, of the size of a horsebean. Total length
of vasa deferentia, 2| inches; their entrance was below and external
to the ureters, which opened as usual. Prostate small. Vesicula
seminales small; they entered § of an inch below the bladder, with
Cowper's glands, which were as large as a tare.

" The thyroid glands were oval, compressed, and small; their co-
lour pale; they began at the 4th ring of the trachea from the thy-
roid cartilage, and extended to the 9th or 10th.

" There was a round subzygomatic gland the size of a pea on the
masseter, and two others of the same character were placed on the
front of the neck, on the platysma myoides.

" The submaxillary glands were thin and long, measuring 1 inch
in length. Their situation was as usual.

" The parotid glands, very extensive but superficial, occupied the

Friday Evening Proceedings at the Royal Institution, 4-85

usual situation ; the duct passed over the masseter, and entered op-
posite the 3rd molar, anterior to the edge of the buccinator.

" The sterno-cleido-mastoideus was attached not only to the mas-
toid process, but also to the whole extent of the occipital ridge ; it
consisted of two portions arising as usual, from clavicle and ster-
num.

" The tongue was thick at its base, which rose abruptly from a
deep furrow surrounding its root ; the distance from its root to the
epiglottis ^ of an inch. Its form was narrow, equal, and rounded at
the tip ; its surface was velvety, and one large central papilla was
seated near its base. Length altogether 2 inches. Breadth ^ an
inch. Length of free part J of an inch. The palate was divided
by elevated transverse ridges into 8 furrows.

''Pharynx spacious, and lined with a corrugated membrane.
(Esophagus narrow, its inner membrane being/puckered longitudi-
nally.

" The anterior surface of the thyroid cartilage was regularly con-
vex, but not so protuberant as in the phalangers ; nor did the os
hyoides play freely over it."

Mr. Edward Burton, of Fort Pitt, Chatham, communicated a de-
scription of a small species of Pipra received from the Himalaya
mountains, and considered by Mr. Burton to be the first species of
this genus yet discovered in those regions. He characterized it as

Pipra squalida.

PROCEEDINGS OF THE FRIDAY EVENING MEETINGS OF THE
ROYAL INSTITUTION.
(Continued from p. 318.)

April 7th. — Mr. Dent on the construction and manufacture of
clocks and watches.

April 14?th. — Mr. Griffiths on capillary and cohesive attraction,
and their application to the art of veneering.

April 21st. — Mr. S.Solly on the central portions of the nervous
system in the animal kingdom.

April !^8th. — Mr. Faraday on a peculiar condition of iron in rela-
tion to its chemical affinity and its electromotive force. (See the
papers by MM. Schoenbein and Faraday in our preceding and
present volume, including two by the former in the present Number.)

May 5th. — Dr. Boase on tin and its application to the arts.

May 12th. — Dr. Mantell on the Iguanodon and other fossil re-
mains discovered by him in Tilgate Forest.

May 19th. — Mr. Warren De la Rue on the history and manu-
facture of playing-cards.

CAMBRIDGE PHILOSOPHICAL SOCIETY.

April 17. — A meeting of the Philosophical Society was held on
Monday evening, the Rev. Dr. Clark, the President, being in the
chair. The Rev. L. Jenyns made some remarks on the unusual de-
gree of cold which prevailed during March. It was stated that the
mean temperature of the month, as deduced from observations made

486 Cambridge Philosophical Society.

at Swaffham Bulbeck, was only 36°'2, being the same as that of Ja-
nuary, and more than six degrees lower than the average mean for
March. The maximum was only 49°, and the minimum 11°; this
last, which was a lower temperature than any experienced since the
hard winter of 1829-30, having occurred on the morning of the
24.th.

Professor Willis exhibited and explained a machine which he
terms a Tabuloscriptive Engine. The object of this machine is to
transfer to paper any numerical series of magnitudes, so as to ex-
hibit the curve which would be obtained by making those magni-
tudes a series of ordinates ; a process of very frequent and impor-
tant use in comparing the results of observations of various kinds,
as, for instance, meteorological, tidal, and statistical observations.
The machine takes three places of figures, is capable of being worked
with very slight attention, and with great rapidity, and produces a
sheet very readily legible and intelligible.

May 1. — A meeting of the Philosophical Society was held on
Monday evening, Dr. Thackeray, V.P., in the chair. A paper by
A. Moore, Esq., of Trinity College, was read, on the solution of a
difficulty of analysis noticed by Sir W. R. Hamilton. — Mr. Whewell
gave an account of the performance of a new Anemometer, invented
by him, which has been erected at the top of the house of the So-
ciety, and also on the top of the Observatory, and of which the in-
dications for the last four months have been recorded. — Mr. Kelland
also read a paper on the effect of the elasticity of the aether in cry-
stals as bearing on the undulatory theory.

May 15. — A meeting of the Philosophical Society was held on
Monday evening. Dr. Clark, the President, being in the chair. A
communication by Mr. G. Green was read, containing the solution
of a problem respecting the motion of a heavy fluid in a canal. — Mr.
Hopkins gave an account of his mathematical researches on the re-
frigeration and the internal fluidity of the earth. — A paper of Mr.
Moseley was read, on the theory of the equilibrium of bodies in
contact.— Mr. W. W.Fisher presented another communication on
the subject of spina bifida. The author has observed, in two cases
oi spina bifida, irregularities which he described; i. e. the union of
two or more of the sacral ganglia ; the passage of their respective
nerves through the sheath in one fasciculus, and the adhesion of
the extremity of the spinal marrow to the walls of the sac. By ap-
plying to the consideration of these anomalies the knowledge which
we now possess of the formation of the different portions of the ner-
vous system in the embryon, and of the anatomy of that system in
the lower order of animals, he is led, with regard to the two ex-
amples he has seen, to adopt the following views.

1. That the union of the sacral ganglia constituted the primary
irregularity to which the anomalous distribution of their correspond-
ing nerves between the ganglia and the spinal cord might be re-
ferred.

2. That, unacquainted with any circumstance connected with the
formation of the spinal cord and its sheath, which can account for

Royal Irish Academy, 487

tlie adhesions between them, he is induced to attribute these ad-
hesions, by which the ascent of the extremity of the cord to its
usual position was prevented, to the irregular manner in which the
nerves had become inserted in the spinal marrow.

3. That the union of the ganglia may be in some measure
ascribed to the development of a process by which the ad-
joining ganglia are in some instances, even of normal conforma-
tion, connected with each other, and that the general occur-
rence of the deformity at the lower extremity of the spinal column
may be attributed to the relative position of the sacral ganglia,
which are placed within the sacral canal, those of the other spinal
nerves being placed in the intervertebral foramina.

4. That the incomplete formation of the posterior wall of the
spinal column is rather to be attributed to the interference occa-
sioned by the irregular development of the corresponding part of
the nervous system than to any peculiar defi(^iency in the process
of ossification.

ROYAL IRISH ACADEMY.

December 12, 1836. — A paper was read ** On the Seals of Ireland
(Phocidse)." By Robert Ball, Esq., M.R.I.A.

The author stated the circumstances by which he was led to dis-
cover that the seal of most frequent occurrence on the Irish coast
was not defined as a British species, together with the subsequent
identification of that animal, by Professor Nilsson, as the Halichcerus
griscus of his Scandinavian Fauna, (Phoca Gryphus of Fabricius,)
found in the Baltic and North Sea. He asserted, however, that the
habits of the Halichaerus of this country differed so much from those
ascribed to it in the Baltic, that it appeared to him not unlikely, on
comparison, to prove a distinct species. He showed that the co-
lour of the animal here varied so much from sex, age, season, &c.,
that it could not be considered of anyvalue as a character of species
in the present state of our knowledge of the subject. He alluded
to the very small size of the brain compared with that of the genus
Phoca, and stated that the intellectual powers bore the same pro-
portion. Mr. Ball then proceeded to show that the simple form of
the teeth of Halichaerus (approaching closely to those of some
species of Delphinus) furnished suflGcient grounds for separating it
from the genus Phoca ; and observed, that the Halichaerus may
always be distinguished from other seals, by its straight profile, fierce
aspect, and greater proportionate length. He mentioned the fact
of his having discovered that the specimen in the British Museum,
so long known as Donovan's Phoca barbatat (and the long-bodied
seal of Parsons,) is formed of the skin of a Halichaerus improperly
stuffed ; and he noticed the mistakes to which this has given
origin.

Mr. Ball next gave instances of the occurrence in this country of
the Phoca Vitulina (P. variegata, Nilss.), which he considered iden-
tical with the seal stated by Sir E. Home (Phil. Trans. 1822) to have
been killed in the Orkneys, though it appears from the cranium

488 Royal L'isJi Academy,

figured as if a few teeth of the P. Groenlandica were inserted into
the upper jaw. The author related some anecdotes of the inter-
esting and beautiful specimen now in the Zoological Gardens ; con-
trasted the species in structure and habits with the Halichaerus;
and expressed his dissent from the statement put forward in Mr.
Bell's British Quadrupeds, on the authority of Professor Nilsson,
that the oblique position of the molar teeth in P. Vitulina was a
specific character of unerring value. He has shown, in fact, that
the obliquity in question arose from the insufficient development of
the jaws in early life, which contracted the space for the teeth ; and
that it disappeared long before the skull reached its maximum size,
and partially occurred in the young Halichaerus.

Mr. Ball then alluded to the seal taken in the Severn, which Pro-
fessor Nilsson pronounced to be his Phoca annellata, but which
has since been stated, with the Professor's concurrence, to be the
P. Groenlandica. He expressed his doubts as to the justness of this
conclusion, observing that the Groenlandica was a large species,
while the Severn seal was certainly a small one. He further showed
that the form of the intermaxillary bones, where they joined the
nasal, was quite sufficient to distinguish it from the specimen figured
by Sir E. Home in the paper before referred to; and he expressed
his belief that the species was still to be determined.

The author concluded by stating his belief in the existence of a
fourth seal (probably P. barbata) on the southern coasts of Ireland,
which he had occasionally seen, but never had opportunity of
closely inspecting; and finally, exhibited a number of sketches illus-
trative of his paper, showing generic and specific distinctions of
external forms, skulls, teeth, caeca, and of the great sinuses of the
hepatic veins.

Professor Kane laid before the Academy specimens of the salts
of a new acid, called by him " Xanthomethilic Acid."

The same gentleman stated some conclusions to which he had
recently arrived, from the examination of pyroacetic spirit, which
he considered to be a new alcohol.

LXXXIX. Intelligence and Miscellaneous Articles.

UPON THE SUPPOSED ABSORBENT POWERS OF THE CELLULAR
POINTS, OR SPONGIOLES, OF THE ROOTS OF TREES, AND
OTHER PLANTS. BY THOMAS ANDREW KNIGHT, ESJJ., F.R.S.
PRESIDENT OF THE HORTICULTURAL SOCIETY.*

AN opinion is very extensively if not generally entertained, that
the nutriment which trees and other plants derive from the soil iri
which they grow, is exclusively taken in by the cellular extremities
of their roots, which, from their texture, have been called Spon-
gioles, and which in their organization differ from other parts of

• From the Transactions of the Horticultural Society, New Series, vol. ii.
p. 117, having been read May 17, 1836.

Intelligence and Miscellaneous Articles, 489

the root in being totally without any alburnous or woody matter
distinct from bark. But it is through the alburnum alone of trees,
as I have proved by a great variety of experiments, and as is, I be-
lieve, generally admitted, that the ascending sap, under ordinary
circumstances, passes up from the roots into their branches and
leaves ; and as this substance does not exist in the spongiole, my
attention was directed to an inquiry, whether the spongioles pos-
sess the power of transmitting fluids, and if such power were found
to exist in them, through what peculiar channels such fluids pass
up : and as these questions are necessarily interesting, and to some
extent, in particular cases, may become important to the practical
gardener, I communicate the result of my experiments.

Spongioles are obtainable in the most perfect state from large
seeds, such as those of the common or French bean, which have
been permitted to germinate, by simply detac^hing them from the
cotyledons, as they thus remain united to the caudex of the plant
and its bud and plumule. Many of these were obtained from the
seeds of plants of several kinds, and subjected to various modes of
treatment in soils of different qualities, but all perished without a
single plumule having expanded, or having apparently received any
nutriment, either from the soil or other source. Yet the spongioles
in these cases must have contained greatly more living organizable
matter, derived from their cotyledons, than the whole body of the
seed of a very large majority of plants can possibly contain 3 but
they were, I conclude, incapable of transmitting it into the plumules
owing to the want of alburnum.

I therefore believe my opinion, that spongioles are imperfectly
organized parts of the plant, which neither absorb from the soil
nor transmit fluids of any kind for the service of other parts of it, to
be well founded ; but alburnous matter is generated with great rapi-
dity within them, and they become to a very great extent trans-
muted into perfect roots long before the growth of the stem or
branches of the tree commences in the spring j and by these newly-
formed roots (but not by these exclusively) 1 conceive that nutri-
ment is absorbed from the soil, and sent up into the leaves, to be
there converted into the true sap of the plant. I am aware that the
above- stated opinions are in opposition to those of many eminent
physiologists, to which much deference is due, but 1 think that they
have erroneously included within their spongioles portions of albur-
nous fibre, a substance never found in the organ properly called a
spongiole.

ACTION OF PRESENCE.

The 60th volume of the Annates de Chimie etde Physique contains
a paper by Pelouze on a new acid, which he calls nitrosulphuric acid''* .
Speaking of the salt which this forms with ammonia, he says, ** the
excessive mobility of tiie elements of nitrosulphate of ammonia, and
the stability which ttie alkalis impart to them, made me think it not

* A translation at length of M. Pelouze's paper has been given id
Scientific Memoirs, part iii. p. 470.

Third Series. Vol. 10. No. 63. June 1837. S R

490 IfUelligence aiid Miscellatieous Articles,

impossible that this salt might exhibit phaenomena of decomposition
of the same class as the singular ones which M. Thenard observed
with binoxide of hydrogen. In fact this is the case ; many sub-
stances which decompose binoxide of hydrogen, without either ac-
quiring or losing anything, also decompose the nitrosulphates.
Spongy platina, oxide of silver, metallic silver, powdered charcoal,
and oxide of manganese, produce this effect -, the two first-men-
tioned especially act with extreme rapidity upon the nitrosulphate
of ammonia.

*' I convinced myself," continues M. Pelouze, " that this remark-
able phgenomenon was due, as in the case of binoxide of hydrogen,
to an action of presence [a une action de presence], and that it never
produces more than a mere conversion of nitrosulphate of ammonia
into protoxide of azote and sulphate of ammonia. Oxide of silver
is not reduced, for if it be washed after having caused it to decora-
pose a large quantity of this salt, it afterwards dissolves in nitric
acid without the disengagement of red vapours."

M. Pelouze afterwards remarks that " it would be very difficult to
discover the probable cause of these singular phaenomena ; but the
verycircumstanceoftheirbeingatpresentinexplicable, they appeared
to me the more to merit the attention of chemists. What indeed
is more calculated to excite curiosity than to observe a salt, by the
mere contact of a body which neither yields anything to nor takes
anything from it, decompose with extreme rapidity into new forms,
among which the agent producing these violent actions remains
chemically passive?

" Two compounds, namely, binoxide of hydrogen and hydruret
of sulphur, are already known as possessing the property of decom-
posing by the influence of a simple action of presence."

Ann. de Ch. et de Phys., Ix. 158.

CATALYSIS. — ACTION OF PRESENCE.

In the 61st volume of the Ann. de Ch. et de Phys., Berzelius has
followed up the remarks of Pelouze on the action of 'presence^ and
has given to it the name of Catalysis. His notice on this subject is
entitled, '^ Some ideas on a new force acting in the combinations of
Organic Compounds."

In inorganic nature, new combinations are formed between the
different bodies which are present, because these bodies have a
greater tendency to combine with each other than with other bodies.
Those bodies which have a great affinity for each other, combine
together, and reject those for which they have a weaker affinity, and
with which they were previously combined, and these also combine
together. Until the year 1800, this tendency of bodies to unite
was the only one known, except heat, and in some cases lights that
could effect their combination. The influence of electricity was of
later discovery, but it was soon also discovered the chemical and
electrical affinity were the same, and that heat and light acted only
by increasing or diminishing these affinities. On proceeding to the
study of orgamc chemistry, very different bodies were obtained
from the same crude material by different organs. In animals, this

Intelligence and Miscellaneous Articles, 4-9 1

crude material, wliicli is the blood, flows in the uninterrupted ves-
sels, and gives rise to all the different secretions ; such as milk, bile,
urine, &c., without the presence of any foreign body which could
form new combinations.

Kirchoff discovered that starch dissolved in acids diluted with
water was converted at a certain temperature into gum and then
into sugar of grapes ; and yet there was no combination between
the elements of the acid and those of the starch, for no disengage-
ment of gas took place. On treating the solution with bases, all the
acid employed was regained ; the solution contained only sugar,
the weight of which only slightly exceeded that of the starch em-
plo3'ed. Some time afterwards, Thenard discovered a new sub-
stance, the binoxide of hydrogen, the elements of which are held
together by very slight affinity. This substance was not decom-
posed by acids, but alkalis gave its elements a^tendency to separate;
slow effervescence occurred with the disengagement of oxygen, and
water was formed. It was soon found not only that soluble sub-
stances produced this efll'ect, but also that other organic and inor-
ganic bodies, such as manganese, silver, platina, gold, fibrin, &c.,
acted in the same manner upon it. This decomposition takes place
by the mere presence of the foreign body, in consequence of a
power which is at present unknown, and without the smallest quan-
tity entering into the new compound, for the most minute researches
failed in discovering the slightest alteration in it.

Edmund Davy discovered that if extremely finely divided platina
be moistened with alcohol, this on taking fire ignites the platina,
and the alcohol, if it contains water, is converted into acetic acid.
This led to the grand discovery of Doebereiner, that spongy platina
has the property of firing a current of hydrogen directed upon it.
This discovery was soon followed by that of Dulong and Thenard,
who found that it was not platina alone that possessed this pro-
perty, but that other bodies, such as gold, silver, and glass, acted in
the same way, but only when they are exposed to a somewhat high
temperature ; whereas platina, iridium, and other metals which ac-
company platina, produce this effect even much below the tempera-
ture of melting ice.

The analogy was observed which exists between the phsnoraena
of the conversion of sugar into alcohol by the presence of a foreign
insoluble body, and that of the decomposition of peroxide of hydro-
gen into water and oxygen, by the presence of platina, silver, fibrin,
and some other equally insoluble bodies. No case analogous to
that of the decomposition of binoxide of hydrogen by the presence
of the alkalis dissolved in this substance was known, for at this
period the analogy of this phaenomenon with that of the formation
of sugar by means of starch and sulphuric acid was not known.
Something similar occurs in one of the hypotheses on the formation
of aether. According to this hypothesis, sulphuric acid should com-
bine with one part of the water contained in the alcohol, and thus
would form aether ; but it could not be explained why other bodies,
such as potash, chloride of calcium, quickhme, &c., which have a

3 R2

492 Intellisethce and Miscellaneous Articles.

•6

very great affinity for water, did not produce the same effect,
Mitsclierlich showed that if alcohol be poured upon sulphuric acid,
at a temperature higher than that of boiling water, water and sether
are distilled together and form a mixture, the weight of which is
precisely equal to that of the alcohol employed. Thus the sulphu-
ric docs not there act in consequence of its affinity for water ; its
action is analogous to that of the alkalis on the binoxide of hydro-
gen J and that of sulphuric acid upon starch in the formation of
sugar.

It is then proved that many bodies, both simple and compound,
soluble and insoluble, have the property of exerting on other bodies
an action which is very different from chemical affinity. By means
of this action they produce decompositions in bodies, and form new
compounds into the composition of which they do not enter.

This new power, hitherto unknown, is common, both in organic
and inorganic nature. 1 do not believe that it is a power which is en-
tirely independent of the electro-chemical affinities of the substance;
I believe, on the contrary, that it is merely a new form of it ; but as
long as we do not see their connection and mutual dependence, it
will be more convenient to describe it by a separate name. I shall
therefore ca-1 it catalytic power, I shall also call Catalysis the de-
composition of bodies by this force, in the same way as the decom-
position of bodies by chemical affinity is termed analysis.

The following are the questions which occur relative to this cata-
lytic power:

Can this catalytic power produce differences in catalytic pro-
ducts, according to its greater or less intensity ?

Can different bodies possessing catalytic power produce different
catalytic effects upon the same compound substance?

Can bodies which possess catalytic power exert this action on a
great number of different compound substances, or is this action
confined to a ^ew substances ?

These questions can be answered only by extended researches ;
it is enough at present to have established the existence of this power
by a sufficient number of examples. This power gives rise to nu-
merous applications in organic nature ; thus it is only around the
eyes of the potato that diastase exists ; it is by means of catalytic
power that diastase, and that starch which is insoluble, is converted
into sugar and into jam, which being soluble form the sap that rises
in the germs of the potato. This evident example of the action of
catalytic power in an organic secretion is not probably the only one
in the animal and vegetable kingdom, and it may hereafter be dis-
covered that it is by an action analogous to that of catalytic power
that the secretion of such different bodies is produced, all which are
supplied by the same matter, — the sap in plants and the blood in
animals.

M. LEVEII.LE ON THE HYMENIUM OF FUNGI.

M. L^veille lately presented to the Academy of Sciences of Paris

Lilelli^ence and Miscellaneous Articles, 493

a paper on the hymeniumiOV fructifying membrane, of the Fungi. In
this paper the author endeavours to establish that the Hymenothecii
which form the fifth order of Persoon's Synopsis Fungorunif which
all authors have adopted and which composes tlie first class of
Fries's Systema Mycologicum, are too numerous; tliat they contain
genera which have no relation to one another; and that they ought
to be divided into two classes.

M. L^veille has taken as a basis the structure of the hymenium ;
he says, that if the surface of the lamina of Agaricus micaceus is ex-
amined in profile with a microscope, two kinds of organs are seen,
the first vesicular, projecting, diaphanous, conical, or cylindrical,
in form of a club, and placed at certain distances one from the
other ; the others representing mammae, more or less projecting,
very close to one another, and ending in four points, each of which
bears a spore. The author gives to the first of these organs the
name of cy slides (from Cystidia), to the secontl that of barides (from
Baridid). The cy slides do not exist in a great number of species,
but the barides may always be found ; their existence may be shown
on the first Agaric met with, on the Dcedale^o^ Boleti, Hydna, Thele-
jphorcB, and Clavarice ; they are tetrasporous, disporous, or mono-
sporous, according as they have two or four divisions j or are simple,
as in the Tremellce. These organs are not new ; Micheli made them
known, as also did Bulliard and Nees von Esenhcck.

After some general remarks on these organs, on the spores, and
their mode of emission, M. Leveille shows that modern authors
have erroneously taken for cells filled with spores the hymenial tissue
itself, which is composed of elongated cells, most of them having
the same direction, parallel to the plane of the receptacle upon
which they are fixed, and not perpendicular as M. Nees has repre-
sented them in his System der Pilze.

The author then treats of the structure of the hymenittm of the
Helvello'ides, which Hedwig made known. Taking as an example
Peziza aurantia, and examining a slice with the microscope, he
found that this hymenium is composed of elongated cells placed side
by side, perpendicular to the plane on which they are fixed ; their
structure consists in a single membrane, thin and diaphanous ; they
contain eight spores, which they eject like a cloud, suddenly, and
from time to time in the air. Among the cells others of the same
length are seen ; they are diaphanous, empty, and filiform. Hed-
wig calls the first ihecce, the second paraphyses -, the existence of
the latter, like that of the cystides, is not constant. A plate, drawn
after nature, by M. Decuisne, represents all these organs taken from
several species of Fungi, and shows that the terms free or fixed
utricules, ascijixi, asci liberie employed by authors to distinguish
the fructification of Agariciy Boleti,ClavaricF, &c., from those of the
HelvellcCy PezizcBy or of the Geoglossa, are improper, and not in the
least suitable. Their differences being known, the division of Per-
soon's fifth order or of Fries's first class into two classes is natural.
The first takes in the Hymenomycetes^ or Basichospori j the second
the Hymcnotheciiy or Thccospori. The one is composed of Agaricif

494 Intelligence and Miscellaneous Articles,

Boleti, Hydnay Clavarioe, Tkelephone, Pistillarice ; the other of
the HelvellcSy Morellce, PezizcPy Spathularice, Geoglossa, &c. The
characters of these two classes have been developed enough in the
foregoing, and it will not be necessary to repeat them.

By making an application of this new division, the genera Sole-
rophyllum and Craterellus will be seen to belong to the first class by
their spores ; the Asterophora of Dittmar belongs to the Birsoidese,
and determines by its presence the abortion of a species o\' Agaricus,
M. Leveille has often found perfectly distinct organs of fructifica-
tion on its hymenium ; the genus Solenia and the Peziza perula of
Persoon must also be referred to this class. It will be necessary to
bring back to the Tliecospori the genera Spathularia, Geoglossiim,
Miirula, and perhaps Sparassis, which have been placed by the side
of the Clavarice more on account of their form than their fructifica-
tion. Finally, the genera Sclerotiuniy Acrospermum, Sclereglossum y
and Spermocdiay whose fructification is not yet known, must be se-
parated from both the classes. The author thinks that the Cantha-
rellusDutrochetiiy which, according to the drawings of M, Turpin,
presents the fructification of the Lycoperdacece or of the Sporotri-
chum, if examined again would come into the first class.

He concludes by observing that he adduces a proof in favour of
the opinion which M. Turpin has started in the Memoires du Mu-
seum d'Histoire Naturellcy and which consists in regarding the
number two as the multiple of the Acotyledons, three and five those
of the Monocotyledons and Dicotyledons. LInstituty No. 203.

ASCENT OF THE SAP.

M. Dutrochet communicated the following observations on the
ascent of the sap to the Academy of Sciences of Paris. When a
branch with leaves is immersed with its basis into water, we know, by
the experiments of Hales and Sennebier, that light exercises a great
influence on the ascent of the sap from the attraction of the
leaves, and that this ascension diminishes considerably in the dark.
Sennebier remarked that this influence varied in different species
of plants, but he deduced from his experiments no general fact.
M. Dutrochet thinks he is able to confirm the following, viz. that
those plants which attract the most water in light are those which
in the dark attract the least; and, on the contrary, those which in
the light attract least, attract the most in the dark.

Linsiituty No. ^i03.

MAGNETIC OBSERVATIONS OF THE AURORA OF FEB. 1 8TH.

The following article may supply the deficiency of magnetic ob-
servations regretted by Mr. Htinektn at p. 266 of our present
volume.

A letter from M. Matteucci, dated from Forli, in the states of the
Church, to M. Donne, announces that the Aurora Borealis of the
18th of Feb. exhibited in that neighbourhood a magnificent spec-
tacle in tlie north and west of the heavens, from nine in the evening

IntelligeJice and Miscellaneous Articles. 495

till one in the mornin<y. This letter contains the observations made
by M. Mattencci, while this phaenomenon lasted, on two magnetic
needles, the one of the length of 0^'05 ; the other shorter, which
in ordinary had 32 and 16 oscillations per minute. In ten succes-
sive observations made during the aurora borealis, the constant num-
ber of oscillations amounted to 30 and 1 3 only. The next morning,
the temperature remaining the same as in the preceding evening,
the needles had returned to their ordinary rate of 32 and 16 oscil-
lations. M. Matteucci adds, that if similar facts should be observed
hereafter, they might serve to elucidate the theory of the aurora
borealis and of terrestrial magnetism. — Institute March 22.

Observations of this phaenomenon are also given in the Proceedings
of the Astronomical Society for March 1837.

In London, by F. Baily, Esq., the President of the Society. —
" The atmosphere had been very cloudy, ^with much rain and
wind during the whole of the evening. But a little after ten
o'clock (mean time), or about three quarters of an hour before
the occultation of Mars by the moon took place, the clouds di-
spersed and left a beautifully clear sky ; at the same time disco-
vering a most brdliant aurora, or rather stream of light, which ex-
tended from the horizon in the west, through the zenith, almost
down to the horizon in the east. This light was of a fine rose co-
lour, being most vivid and brilliant in the western horizon ; and, as
it approached the zenith, was evidently impaired by tlic strong light
of the moon, then near her full, and high on the meridian. The
aurora appeared very steady, and unaccofiipanied by any corusca-
tions. It lasted till about half-past eleven o'clock, and wholly dis-
appeared before midnight. By subsequent accounts which have
been received, it was seen in the western parts of Ireland, and in
Scotland."

At Makerstoun, near Kelso, Scotland, lat. 55° 34' 45" N.,
long. 10™ 4^ west of Greenwich; by Sir T. M. Brisbane. — " On
quitting the observatory, at about 10*^ 35^, I was struck by a
most extraordinary red appearance in the sky, extending as far
west as the constellation of Orion, and as far east as that of Leo.
It was principally north of the moon — none of it very near her; and
might have been at least 10 degrees in breadth, of almost a deep
red colour. I found all the servants out, looking at it with surprise
and astonishment. It was followed next day by snow, rain, and
a gale of wind. Observed also a very beautiful lunar halo, of nearly
5' in diameter : the colour principally orange, but it did not last
many minutes."

At Ashurst, in Kent, by Mr. Snow. — " A very remarkable Aurora
Borealis became visible at ten o'clock. It commenced with a very
fine deep red arch, extending over the zenith from the east and
west, and slanting away, as it were, at an altitude of about 30° to-
wards the horizon in the N.E. and N.W. Its appearance was mag-
nificent, although the moon was very bright, and not far from the
meridian. When it was first noticed, the clouds that were driving
off to wards the east were deeply tinged with the red colour. After

496 Intelligence mid Miscellaneous Articles.

undergoing some changes, difficult to describe, it grew fainter at
twenty minutes before eleven. A white arch then appeared in the
usual situation of the Aurora, giving out white streamers at a few
minutes before eleven. This latter arch was not well defined. At
ten minutes after eleven the Aurora had almost entirely disappeared,
excepting a reddish patch between Arcturus and Regulus, which in
ten minutes more was no longer to be seen. After this the wind,
which during the day had been at S.W., shifted to the N.VV., with
a cloudless sky, and ren»ained so until the morning. The stars,
however, became gradually very ill defined ; and during the whole
of the next day and night there fell unceasing torrents of rain, with
a gale of wind from the south-west."

ON THE DECOMPOSITION OF CARBONATE OF LIME BY HEAT.

M. Gay-Lussac observes, that it has long been supposed that the
calcination of limestone is accelerated by the presence of water ;
and tlie opinion appears to be adopted by lime-burners in general.
M. Dumas admits the influence of water to be unquestionable, and
he gives two explanations of its action ; either, says he, it acts upon
the carbonate, and forms a temporary hydrate, taking the place of
the carbonic acid for a very short time, for the hydrate of lime it-
self is decomposed by a red heat ; or the water being decomposed
by the carbon, employed as a combustible, is converted into various
gases, of which carburetted hydrogen forms a part, and this re-
acting upon the carbonic acid of the carbonate tends to convert it
into oxide of carbon, and thus facilitates the separation from the car-
bonate of lime. Thus, limestone fresh quarried, and consequently
still moist, ought to be more readily calcined than the stone which
is nearly dry ; and most lime-burners are well acquainted with this
fact, and sprinkle with water the limestone which has been long
procured before they charge the kilns with it. (Dumas, Traits de
Chimie, ii. p. 482.)

The first of these explanations is, however, inadmissible, for
hydrate of lime is decomposed at a temperature considerably lower
than that at which carbonate of lime is decomposed under the in-
fluence of water.

On considering the circumstances of the combustion in limekilns,
the second explanation does not appear to M. Gay-Lussac to be ap-
plicable, and he therefore proceeds to some observations which he
thinks will explain the influence of the water.

A porcelain tube was filled with bits of marble and placed in a
furnace, the heat of which was easily regulated ; a glass retort con-
taining water was adapted to one end of the tube, and at the other
end a glass tube to receive the carbonic acid gas. The heat was
raised sufficiently high to decompose the marble, and on shutting the
ash. pit door the heat fell to a dull red, and the carbonic acid ceased
to come over ; and at this instant the water was boiled in the re-
tort, and carbonic acid was abundantly obtained. On disconti-
nuing the vapour, the disengagement of acid instantly ceased, and
returned only on continuing the vapour.

Intelligence and Miscellafieous Articles, 497

It appears, therefore, proved that the vapour of water actually
favours the decomposition of the carbonate of lime by heat, and
that by its operation this decomposition may occur at a lower tem-
perature than is otherwise requisite.

M. Gay-Lussac considers the action of the water to be entirely
mechanical. When the carbonate of lime is exposed to heat, and
is near the point of decomposition, an atmosphere of carbonic acid
is formed around it, which presses upon the acid remaining com-
bined, so that the latter, that it may be disengaged, must overcome
the pressure of this atmosphere. This, however, cannot occur
without still further raising the temperature, or removing the car-
bonic acid and forming a vacuum, or by displacing it, either by the
vapour of water, or some other elastic fluid, such as atmospheric
air.

This explanation is supported by the following experiment; car-
bonate of lime was heated in a porcelain tube nearly to its decom-
posing point, and then a current of atmospheric air was passed over
it. The disengagement of carbonic acid immediately commenced,
continued wiih the current of air, ceased when it was stopped, and
recommenced with it.

M. Gay-Lussac, therefore, considers it as proved, that the influ-
ence of aqueous vapour, in the calcination of limestone, is confined
to the production of a vacuum for carbonic acid, and to the pre-
vention of the pressure of the disengaged acid upon that which re-
mains with the lime. When the vapour is present, a lower tem-
perature is required to dislodge the carbonic acid ; but the impor-
tance of this influence must not be overrated. The water, in calcare-
ous stones, is mechanically interposed between their particles ; and
with the exception of some minute portions, which remain confined
in the centre of pieces too large to allow of the heat penetrating
and vaporizing them, the greater part of the water must evaporate
without any useful result ; and, on the contrary, with the loss of
fuel, before the limestone has acquired the temperature requisite
for its decomposition.

M. Gay-Lussac thus concludes : " I am certainly convinced that
the vapour of water favours the calcination of limestone, but I am
doubtful as to its possessing real advantages, because there is not
a great difference in the temperature at which it decomposes, alone
or with the vapour of water : besides, if the vapour of water only
exerts a mechanical action similar to that of atmospheric air, any
important advantage which it possesses over the aeriform current
continually passing over the burning mass, is not evident.

The readier decomposition of carbonate of lime by the access
of aqueous vapour, or rather by means of a vacuum, cannot be con-
sidered as an isolated fact. It may be regarded as an established
principle, that when one or several gaseous products are obtained,
either by the action of heat or a chemical agent, the decomposition
may be generally facilitated, by keeping the bodies in vacuo, or by
preventing the gaseous fluids from pressing upon it. And on the
other hand, the decomposition may be retarded or entirely pre-

Third Series. Vol. 10. No. 6l3. June 1837. 3 S

4-98 Intelligence and Miscellaneous Articles.

vented by forming round the body a sufficient pressure of an elastic
fluid of the same nature as that which is to be disengaged. It is
thus in the curious experiment of Hall ; carbonate of lime was fused
at a very high temperature, without being decomposed, under the
influence of a sufficient pressure of carbonic acid.

Jnn.de Ch. et de Ph. Ixiii. 219.

PREPARATION OF IODINE. BY M. BUSSY.

The process of extracting iodine generally followed, and which
consists in decomposing the mother- waters of kelp by means of con-
centrated sulphuric acid, is well known to be liable to variable re-
sults, on account of a portion of the iodine coming over in the state
of hydriodic acid and chloride of iodine, so that in either case there
is always a considerable loss.

To avoid this inconvenience, M. Soubeiran proposed to preci-
pitate the iodine from the mother-waters by means of sulphate of
copper, and afterwards to decompose the iodide of copper by per-
oxide of manganese at a high temperature*. But this process re-
quires minute attention and much precaution to separate the whole
of the iodine existing in the mother-waters, and we do not believe
that it has ever been employed in any manufactory.

These circumstances induce me to publish a far more simple me-
thod, which has been lately employed by some manufacturers of
iodine ; it was discovered (if we are rightly informed) by M, Bar-
ruel, director of the chemical works at the Faculty of Medicine ; it
consists in precipitating the iodine of the mother-waters of kelp by
a current of chlorine.

In this process the mother-waters are first to be evaporated to dry-
ness, and to the residue there is to be added a tenth of its weight of
powdered peroxide of manganese; the two substances are to be per-
fectly mixed, and subjected to a dull red heat in an iron vessel,
frequently stirring them ; the object of this calcination is to convert
the sulphurets and hyposulphates, of which the mother-waters con-
tain a large quantity, into sulphates. It is extremely easy to deter-
mine when these compounds are converted into sulphates by taking a
small quantity of the calcined matter and pouring upon it an excess
of sulphuric acid. It ought not to yield, when the conversion is per-
fect, either sulphuretted hydrogen or a deposit of sulphur. If violet
vapours are disengaged during the calcination, the heat must be
lowered to avoid loss. When the sulphurets are decomposed, the
residue is to be dissolved in a sufficient quantity of water to give a
solution of sp. gr. 1-333 j through this solution there is then to be
passed a current of chlorine gas, taking care to stir it constantly
with a glass rod : the liquor becomes of a deep brown colour, after-
wards turbid, and deposits iodine in the form of a black powder; it
is to be collected and distilled in a glass retort, in order to procure
it in crystals. The only difficulty in this process is to determine
the point at which the action of the chlorine should cease, that no

* Journ. de Pharmacie, torn. ii. p. 411.

Litelligence a?id Miscellafieous Articles. 499

excess may be used which would react upon the iodine precipitated.
This excess of chlorine is especially to be apprehended, when it i^
also intended to separate from the same mother-waters the bro-
mine which they contain.

In order to avoid adding excess of chlorine, the liquor which is
supposed to be near saturation, may be suffered to settle for a short
time, and the current of chlorine being interrupted it is to be di-
rected on the surface of the liquid. If it contain any iodide in solu-
tion, a pellicle of iodide will be observed to form on the surface ;
this effect is not produced when all the iodine is precipitated ; in the
latter case the liquor becomes quickly clear and retains only a
reddish tint.

PREPARATION OF BROMINE. BY M. BUSSY.

The separation of bromine, as usually performed, also involves
great difficulties, which may be avoided by the following process.

This process greatly resembles the preceding one ; it is founded,
like it, upon the great affinity of chlorine and the property which it
possesses of displacing bromine from its combinations. It also
includes the employment of the mother-waters of iodine, which
without it are useless. Take the mother- waters of kelp, after having
separated the iodine by chlorine as above described. These mother-
waters contain a metallic bromide, when care has been taken to
avoid the use of more chlorine than sufficient to precipitate all the
iodine. Add to 1250 parts of these mother-waters, thirty-two parts
of powdered peroxide of manganese, and twenty-four parts of sul-
phuric acid of sp. gr. 1'848 : the whole is to be put into a tubu-
lated glass retort, to which a tubulated receiver is to be adapted,
and to this a tube which is immersed in a test tube. The retort
and the receiver, as well as the receiver and the tube, ought to fit
sufficiently well without the use of lute or corks, as they would be
inevitably destroyed by the action of the chlorine. All being thus
arranged, the retort is to be heated, so as to boil the liquid ; the
bromine condenses in the receiver in the form of red oily striae, with
a small quantity of water ; the operation is to be discontinued when
red vapours cease to be produced. On heating the receiver gently,
without dismounting the apparatus, the bromine will pass into the
test-tube, where it will condense on cooling.

The mother-waters which have been made use of may be re-
jected, on ascertaining by the addition of a fresh quantity of sul-
phuric acid and peroxide of manganese that they contain no more
bromine. Journal de Pfiarmacief January 1837.

ON THE RED AND WHITE OXIDE OF PHOSPHORUS. BY
M. MULDER.

Pelouze considers the white crust which covers old sticks of
phosphorus as hydrate, and H. Rose regards it as differing from
common phosphorus only by its state of aggregation. The red
powder which sometimes covers phosphorus may be prepared by

3S2

500 Intelligence afid Miscellaneous Articles,

passing a current of oxygen gas on phosphorus melted under hot
water, in which operation the phosphorus combines with this gas,
giving out light and heat. It is therefore proved that the red powder
is an oxide.

Some time since I received some sticks of phosphorus which had
been kept for thirty years in the same bottle and exposed to
the light. Their surface was perfectly white, and covered with
a crust of this white matter to the thickness of about yj^ of an inch.
1 removed these cylinders into another bottle filled with pure di-
stilled water, and was surprised on finding the day after that they
had become entirely red : although they have been four years in
contact with light, they retain the same fine red colour.

This observation is adverse to the opinions of Pelouze and Rose.
The only idea which I can form as to this sudden change of the
white crust into red oxide by distilled water is, that the minute
quantity of oxygen in the distilled water had converted the white
crust into oxide, and since this quantity of oxygen is very small,
the white matter could not be an oxide. I imagined that the phos-
phuretted hydrogen, which is always formed by phosphorus in wa-
ter, might be the cause of it.

To satisfy myself respecting it, I passed a current of phosphu-
retted hydrogen gas into water containing red oxide of phosphorus
in a state of minute division. By this operation the red oxide was
gradually reduced to the white matter; which in its turn was in some
days after changed into red oxide, on removing it, without the con-
tact of light, into fresh water, in which oxygen was dissolved.

It is evident from this that the white crust of phosphorus is a
combination of phosphuretted hydrogen and red oxide of phosphorus,
and that there is therefore only one oxide of phosphorus, and which
is of a red colour.

On keeping phosphorus in water the latter is decomposed; oxide
of phosphorus and phosphuretted hydrogen are formed, a part of
which combines with the oxide of phosphorus, and gives rise to the
.white matter described. Journal de Pharmacie, Jan. 1837.

ACTION OF IODINE ON THE VEGETABLE ALKALIS.
M. Pelletier remarks that it has not been determined whether the
bodies which are termed halogen combine with the vegetable alkalis,
or exert an elementary action upon them which alters their compo-
sition. Are iodine, bromine, and chlorine converted into iodides
and iodates, bromides and bromates, chlorides and chlorates by
the influence of the salifiable bases ? Do iodites, bromites, and
chlorites exist, or is the organic base decomposed ; and if so, is
chlorine, bromine, or iodine substituted for hydrogen ? These are
the principal points which attracted M. Pelletier's attention, and
he arrived at the conclusion that iodine is capable of combining
immediately witli the greater number of organic salifiable bases ;
and that from its union with these substances there result definite
combinations of this elementary body and the vegetable alkalis.

Intelligence and Miscellaneous Articles^ 601

Iodine and Strychnia.— The properties and composition of this al-
kaWy its insolubility, and the facility with which it forms definite com-
pounds and crystallizable salts, were the reasons for selecting it in
preference to others in commencing the investigation. Strychnia
triturated with half its weight of iodine became of a reddish brown
colour ; distilled water was added and the trituration continued.
The filtered solution was colourless, and neither acid nor alkaline,
and exhibited but slight traces of iodine or strychnia. The mat-
ter remaining on the filter was treated with boiling water, which
became of a light rose colour ; when filtered and evaporated it left a
very light residue. It consisted of iodide with a small portion of
hydriodate of strychnia, as was afterwards proved.

The brown matter insoluble in water was subjected to the action
of boiling alcohol ; it dissolved entirely, and the solution was of an
orange yellow colour : by cooling it deposited a great quantity of
small laminated crystals, of an orange yellow colour and resembling
aiirum musivum. More and similar crystals were obtained by eva-
poration ; but quite at the end of the operation white acicular crystals
were procured which were hydriodate of strychnia; both these
kinds of crystals may be obtained by the direct action of alcohol on
a mixture of iodine and strychnia.

This laminated substance has the following properties : it is in-
soluble in cold water, and very slightly soluble in boiling water ;
it is but little dissolved by weak alcohol, its best solvent is strong
boiling alcohol ; on cooling the greater part of it separates in
micaceous scales ; it is insoluble in sulphuric aether.

Its taste is at first but slight, but after a certain time it is bitter
and slightly astringent. It is infusible at 212°, and at all temper-
atures below its point of decomposition ; when heated upon platina
foil, it softens, swells, yields iodine, and chars almost at the same
time, emitting the smell peculiar to organic salifiable bases when
decomposed by heat.

Acids, according to their nature and concentration, act differently
on this substance. In general when they are very dilute and cold,
they do not act sensibly upon it ; but by long ebullition they se-
parate the iodine and unite with the strychnia, which may be pre-
cipitated by ammonia.

Concentrated nitric acid, even when cold, separates iodine and
destroys or alters the organic matter ; concentrated sulphuric acid
produces the same effect, but not so rapidly. Concentrated hydro-
chloric acid has no effect upon this substance when cold, but when
heated it combines with the strychnia and separates the iodine.

Ammonia does not act upon this substance, either cold or hot ;
and potash and soda affect it only when heated ; a little strychnia
is separated, and iodide of potassium or sodium remains in solution.
By the successive action of acids and alkalis upon the micaceous
compound, it is eventually decomposed, and they show that it is an
iodide of strychnia.

The proportions of the iodine and strychnia, which exist in com-

502 Intelligence and Miscellmieous Articles,

bination, were determined by the action of nitrate of silver upon it.
Iodide of silver is precipitated, and the strychnia, which has suffered
some change, combines with the nitric acid.

The analysis was performed by determining the quantity of iodide
of silver obtained, for the iodine ; and another portion of the com-
pound, deprived of its iodine by the action of acids and alkalis, was
decomposed by oxide of copper. The salt consists of

One equivalent of iodine 126

One equivalent of strychnia 2S4 — 360

lodate of Strychnia. — Supposing the iodide of strychnia to be con-
verted into iodate of strychnia, it would consist of

One equivalent of iodic acid ... . 166.... 41 '5
One equivalent of strychnia .... 234 .... 58*5

400 100-

In order to compare the formula indicated by theory with the
composition of the salt yielded by direct analysis, strychnia reduced
to fine powder was diffused through warm water, and iodic acid was
added to it, dissolved in rather a large quantity of water ; by filtra-
tion and evaporation flat acicular crystals were obtained. Care
must be taken to avoid excess of acid, as by its action upon the
strychnia an acidulous iodate is obtained of a red colour. Io-
date of strychnia may also be procured by decomposing neutral
sulphate of strychnia by means of iodate of barytes. The crystals
thus obtained resemble cyanide of mercury in appearance.

The following method was employed for analysing this iodate
and the organic iodates in general ; the iodate of strychnia was
dissolved in water and decomposed by excess of potash. The liquor
without filtration was evaporated in the capsule which contained it ;
iodate of potash remained, with free strychnia and excess of potash ;
the strychnia was decomposed by calcination, adding a little nitrate
of potash in order to burn the carbon ; the iodide of potassium was
redissolved in the water and precipitated by nitrate of silver ; the
iodide of silver is to be treated with dilute nitric acid to separate
the oxide of silver ; care must be taken not to saturate the solution
with nitric acid before precipitation.

To determine the quantity of strychnia the salt was heated with
oxide of copper, and calculating from the usual data, the composi-
tion of the iodate of strychnia appeared to be

Iodic acid 41*64

Strychnia 58-36—100

These proportions agree almost precisely with those already de-
duced from theory ; and show that it is a neutral salt consisting of
an equivalent each of acid and base.

Hydriodate of Strychnia. — The neutral salt could not be obtained :
the subsalt procured is but slightly soluble ; it may be formed either

Intelligence and Miscellaneous Articles* 503

by directly cotnbininjr the acid wit!) the alkali, or by decomposing a
soluble salt of strychnia by an alkaline hydriodate. This salt is
white, formed of small laminae or flattened needles adhering together;
although but slightly soluble in cold water, its taste is very bitter ;
it is more soluble in alcohol than in water. It does not act upon
litmus paper. It is a subsesquihydriodate, composed of

One equivalent of hydriodic acid .... 127 . . 26*6
One and a half equivalent of strychnia 351 .. 73*4

478 100-
The following singular reaction, in the opinion of M. Pelletier,
throws great light on the theory of organic iodides : When a solu-
tion of a neutral iodate of strychnia is poured into a solution of an
hydriodate of the same base, no apparent decomposition takes place;
but if iodic acid or an acidulous iodate be substituted for a neutral
one, a brown precipitate is obtained, formed of iodide of strychnia
and free iodine. When this precipitate is macerated in a solution
of bicarbonate of potash, the excess of iodine dissolves, and the iodine
then assumes the orange yellow colour which belongs to it, and it
then resists the action of the bicarbonate.

In this decomposition the five equivalents hydrogen of the hydri-
odic acid of five equivalents of hydriodate of strychnia combine with
five equivalents of oxygen of the iodic acid to form water, and the five
equivalents of strychnia are precipitated with six equivalents of
iodine, one of which is dissolved by the bicarbonate of potash, and
five equivalents of neutral iodide of strychnia remain.

If also an acid be added to a mixture of neutral iodate of strychnia
and of hydriodate, either neutral or a subsesquihydriodate, a brown
precipitate is formed of iodine and iodide of strychnia. This action
is explained by what is above stated.

An. de Ch. et de Phys. tom. Ixiii. p. 164.

METEOROLOGICAL OBSERVATIONS FOR APRIL 1837.

Chiswick. — April 1, 2. Fine. fi — 6. Cold and dry. 7. Hail showers.
8 — 10. Bleak and cold, with an exceedingly dry atmosphere. 1 1. Clear
and fine. 12. Hazy: bleak and cold. 13. Overcast : cold and windy.

14. Overcast. 15. Clear: fine. 16. Snowing: cloudy and cold. 17. Cloudy
and cold. IS. Overcast: slight rain. 19. Hazy: fine. 20. Fine: rain.
21. Rain. 22. Fine. 23. Rain. 24. Very fine. 25. Fine. 26. Very
fine. 27. Slight rain: fine. 28, 29. Slight rain. 30. Rain : fine.

Boston. — April 1, 2. Fine. 3. Cloudy : rain and snow early a.m.

4, Fine ; snow early a.m. 5. Fine. 6. Fine: hail early a.m. 7, 8. Fine.
9. Snow : snow P.M. 10. Fine. 11, 12. Cloudy. 13. Snow. 14. Fine.

15. Cloudy. 16. Rain and snow. 17. Stormy. 18— 20. Cloudy.
21. Fine: rain p.m. 22. Cloudy: rain early a.m.: rain and hail p.m.
23. Cloudy: rain A.M. 24. Cloudy. 25. Fine. 26. Fine : rain early
a.m. 27. Cloudy : rain p.m. 28. Fine. 29. Cloudy: rain a.m. and
P.M. 30. Cloudy.

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April.

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INDEX TO VOL. X,

i\ CHROMATIC light In solar and oxy-

hydrogen microscopes, 184.

Acids: — anhydrous sulphuric, 157; anilic,
325; bombic, 323; boracic, 4l9; car-
bonic, 158, 496; iodic, 93; mellitic,
159; nitric, 172, 269, 27P, 326; nitro-
sulphuric, 489; oenanthic, 418, 422; pe-
riodic, 325 ; phosiphoric, 217, 218; pi-
cric, 325; sulphindylio, 324 ; sulphopur-
puric, 324; sulphuric, 324; sulphurous,
235 ; xanthoniethilic, 488.

iEther, oenanthic, 418.

Afzelius (A.), notice of, 470.

Albumen, nature and properties of, 85;
action of electricity on, 357 ; and bichlo-
ride of mercury, compound of, 420.

Alcohol and indigo, their analogy consi-
dered in their combination with sulphuric
acid, 324.

Alkalis, vegetable, action of iodine on the,
500.

Aloe plant of Socotra, 226.

Amidone, solubility of, 247.

Ammonia, solvent action of muriate and
nitrate of, 95, 178, 333.

Amphibole, analysis of, 238.

Analysis, a new theorem in, 28.

Anchor, found at Seaton, 10.

Andrews (Prof.) on thermo-electric cur-
rents, 433.

Anorthite and btotine, identity of, 368.

Antimoniuretted hydrogen, 343.

AraneidsD, a new genus and some unde-
scribed species of, 100.

Arch, oblique, "4, 167.

Argonauta, Linn., 303.

Arsenic, vegetation in a solution of, 324 ;
Marsh's test for, 353.

Artificial crystals, results of experiments on
the production of, 171.

Artificial substance resembling shell, 201.

Accent of mountains, on the, 261.

Asia Minor, geology of, 68.

Astronomical Society, 227.

Astronomy : — on the solar eclipse of May
15, 180; Wrottesley's catalogue of the
right ascensions of 1318 stars, 227 ; pro-
jectionsof maps and charts, 229; Struve's
work on the measure of double stars,
229 ; remarkable phenomenon that «)r-
curs in eclipses of the sun, 230; aurora
borealis, 75, 76, 77, 265, 494, 495.

Augite, analysis of, 237.

Aurora borealis, 75, 76, 77, 265»494, 495.
Third Series. Vol. 10. 3

Babbage (C.) on some Impressions in sand-
stone, 474.

Babington (C. C.) on some species of
Polygonum and Fagopvrura, 223.

Baily (F.) on a remarkable phenomenon
that occurs in total and annular eclipses
of the sun. 230.

Bale ( Rev. 8. ), notice of, 464.

Ball (R.) on the seals of Ireland, 487.

Barton (J.) on the physical causes of the
phenomena of heat, 342.

Baryto-calcite, composition of the, 373.

Becquerel (M.) on the reduction of metals
by electricity, 154; on an electro-mag-
netic balance, and on a battery with in-
variable currents, 358.

Bennett (E. T.), notice of, 465.

Berzelius (Baron), a Copley medal award-
ed to, 212.

Bianchi (Prof.) on a new sidereal cata-
logue, 67.

Biotine and anorthite, identity of, 368.

Bird (G.) on the nature and properties of
albumen, &c., 85 ; on the action of elec-
tricity on albumen, 357 ; on electric cur-
rents of low tension, 376.

Elackwall (J.) on a new genus and unde-
scribed species of Araneidae, 100.

Boase (Di.) on Mr. Hopkins's researches
in physical geology, 14 ; on the compo,
sition and origin of porcelain earth, 348.

Boron, preparation of, 419.

Botany ; — classification of vegetables, 37»
108 ; a grass (Spartina glabra) new to the
, British Flora, 71 ; on the Esula major
Germanica of Lobel, 7 1 ; on the tree from
which the Indians prepare th« poison
called wooraly or ourary, 72 ; Aphy-
teia Hydnora and Cynomorium cocci-
neum, 73; descriptions of two species of
Coniferte, 73 ; notice of M. Jussieu,
153 ; descriptions of Polygonum and Fa-
gopyrum, 223; Polygonum dumetorum
and Epipac is purpurata, 225; manna
of Mount Sinai, dragon's blood tree
and aloe plant of Socotra, 226 ; on the
absorbent powers of the roots of trees,
488; on the hymenium of fungi, 492;
ascent of the sap, 494.
Brain, human, 286 ; on the accumulation
of fluid in the, 316; in marsupial ani-
mals, 222.
Brett (R. H.) on the solvent action of nou-
riate and nitrate of amu.onia, 95, 333.

506

INDEX.

Brewster (Sir D-), examination of an arti-
ficial substance resembling shell, 201.

Bridges, ol)lique, 74, 167.

Bromine, jjreparation of, 499.

Brooke (H. J.) on the crystallographical
identity of certain minerals, 170 ; on the
intersection of crystalline minerals, 278.

Buckland (Dr.) on silicified trunks of trees
in the new red sandstone, 475 ; Bridge-
water Treatise, 410.

Bussy (M.) on the preparation of iodine,
498 ; preparation of bromine, 499.

C. J. on Fresnel's theory of double refrac-
tion, 24.

Callan (Prof.), reply to Dr. Ritchie, 459.

Cambridge Philosophical Society, 316, 485.

Camphor, experiments on, 420.

Carbonate of lime, its decomposition by
heat, 496.

Carbonic acid, solid, degree of cold pro-
duced by, 158.

Catalysis, a new force acting in the corabi-
ra'ions of organic compounds, 490.

Charlesworth (Edw.) on the crag, and on
the relative age of tertiary deposits, 1.

Chemistry, organic, researches in, 45, 116.

Chloral, a new compound analogous to,
321.

Chloride of calcium, compound of, with
pyroxylic spirit, 47.

Chlorides, metallic, action of sulphuric
acid on, 157.

Chlorine, its action on pyroxylic spirit, 49 ;
decolorizing combinations of, 155.

Chloroform and cyanoform, on, 322.

Claik (Dr.) on cyanide of potassium, 329.

Clarke (E. M.) rt-piy to Mr. Saxton, 455.

Clemson (T. G.) on a vein of bituminous
coal in the island of Cuba, 161.

Coal, bituminous, of Cuba, 161.

Cocoa-nut paim, crystallized sugar from the
juice of, 77.

Cold, produced by solid carbonic acid, 158.

Coiebrook (Lieut. Col.) on making cry-
stallized sugar from the juice of the co-
coa-nut pal in, 77. •

Collimator, Amici's, 234.

Coniferac, descriptions of two species of, 73.

Connell (A.) on the action of voltaic elec-
tricity on iodic acid, 93.

Cooper (P.) on molecular action, 355.

Copley medals, awarded to Baron Berze-
lius and F. Kiernan, Esq., 212.

Crystalline minerals, intersection of, 278.

Crystalline reflexion, laws of, 42.

Crystallized iron pyrites, artificial, 158.

Crystals, artificial, on, 171 ; optical phe-
nomena of, 2 IS.

Cuba, bituminous coal of, 161.
Cuckoo, notice of the, 305.
Cyanide of potassium, as produced in hot-
blast furnaces, 329.
Cyanoform and chloroform, on, 322.
De la Rue (W. ) on a voltaic battery charged
frttb Aoiutiou of sulphate of copper, 244.

Devonshire, geology of, 388.

Diastase, its action on starch, 247.

Dioptric light, new, 176.

Dispersion pi liiiht, theory of the, 221.

Doebereiner (jVI.) method of obtaining
spongy platina, 154.

Don ( Prof. ) on two species of Conifcrw^
73.

Dragon's blood tree of Socotra, 226.

Dudley coal-field, on the, 313.

Dumas (M.) on camphor, 420.

E. W. B. on the silent flight of Musca t«»-
tnitoria, 327.

Earth, porcelain, composition of, 348.

Eclipse, solar, 180; remarkable phenome-
non that occurs in, 230.

Electricity, 12,57, 60, 63, 65, 9.3. 130»
133, 154, 171, 172, 175, 193, 241, 244,
267, 276, 280, 281, 317, 320, 326, 357^
358, 376, 425, 428, 433, 455.

Electro-magnetic balance, 358.

Electro-magnetic machines, 12,455.

Enamel, art of painting in, 442.

Entomology : — a new genus and unde-
scribed species of Araneidte, 100; volun-^
tary sounds of insects, 327 ; new hyme-
nopterous insects, 440.

Essex (Alfred) on the art of painting io
enamel, 442.

Eye, symmetrizing power of the, 234, S70.

Faraday ( Prof.) on the causes of the neu-
trality of iron in nitric acid, 175.

Felis niarmorata, a new species, 481.

Ferussac (Baron), notice of, 310.

Fisher's (W. W.) account of a case of spin»
bifida, 316, 486.

Forbes ( Prof.) on the physical development
of man, 197; on the ascent of moun.
tains, 261.

Forster (Edward) on the Esula major
Germanica of Lobel, 71.

Fox (C.) on the oblique arch, 167.

Fox ( R. W.) results of his experiments on
the production of artificial crystals, 171.

Fox of the Himalayan mountains, 304.

FVesnels theory of double refraction, on,
24 ; law of reflexion, 43.

Fungi, hymenium of, 492.

G. on a property of the parabola, 32.

Gay-Lussac (M.) on the decomposition of
carbonate of lime by heat, 496.

Geological Society, 68, 136, 306, 388, 471.

Geology : — on the crag and tertiary depo-
sits, 1 ; anchor found at Seaton, 10 ; Dr.
Boase on Mr. Hopkins's researches in
physical geology, 14 ; geology of Asia
Minor, 68 ; on changes in the level of sea
and land in W. of Scotland, 136; dis-
tribution of organic remains on the York-
shire coast, 137; on a vein of bitumi-
nous coal in Cuba, 161 ; on the Coal-
brook Dale coal-field, 311 j composition
of porcelain earth, 348 ; on the carboni-
ferous series of New York and Pennsyl-
vania, 365; Mr. Ly-eU's address at the an-

I N D E X.

5o;

niversary of the Geological Society, 308,
388 ; mineral veins, 394 ; proofs of mo-
dern elevation and subsidence, 397 j or-
ganic remains, 402 ; on hills of gravel
containing marine shells, 471 ; geology
of the 'I'hracian Bosphorus, 47'? ; on
some impressions in sandstone, 474 ; si-
Jicified trunks of tree.s in new red sand-
stone, 475 ; petrified piece of wood from
a Roman aqueduct, 476 ; raised beach
in Barnstaple bay, 477.

Gilks (Wm.) on the aurora borealis, Oct.
II, 77.

Glass-enamel, 444.

Glass- pain ting, 443.

Gould (J.) descriptions of various birds,
287, 290, 293, 295.

Graham ( Prof. ) on the constitution of salts,
216.

Graves (J. T. ) on the symmetrizing power
of the eye, 370.

Hall ( Dr. M. ) on the reflex function of
the spinal marrow, 51, 124, 187, 378.

Hamilton (W. J.) on the geology of the
Thracian Bosphorus, 473.

Hawfinch, 72.

Heat, in uncrystallized media, transmission
of, 336; physical causes of the pheno-
mena of, 342.

Heineken (N. S.) on an anchor found at
Sealon, 10; on the aurora borealis of
Feb. 18, 265.

Helm wind, on the, 221.

Henry ( Dr. W.), notice of, 152.

Herschel, (Sir J. F. W.), the Royal medal
awarded to, 213.

HoflTman (Prof.), notice of, 308.

Holditch (Rev. H.) on a property of the
parabola, 35.

Hopkins's researches in physical geology,
remarks on, 14.

Horner (L.) on an artificial substance re-
sembling shell. 201.

Horsburgh (Capt), notice of, 149.

Hydrate of magnesia, on, 454.

Hydrogen, antimoniuretted, 343.

Hymenium of fungi, 492.

Hymenopterous insects, new, 440.

Imperial standard troy pound, 63.

Indigo, analysis of, 324 ; analogy of alco-
hol and indigo, in their combination with
sulphuric acid, 324.

Infinite series, formulae for the summation
of, 121.

Infusoria, fossil, used for food, 318,

Insects, voluntary sounds of, 327.

Integral calculus, 210.

Interference of light, experiment on the,
364.

Intestinal worm, double-bodied, 253.

Inulin, how obtained, 249.

lodal, a nevv compound, 321.

Iodic acid, action of voltaic electricity on,
93.

I«dine, protochloride and terchloride of,

430 ; preparation of, 498 ; its action on

the vegetable alkalis, 500; iodine and

strychnia, 501.
Iron, peculiar voltaic condition of, 13S,

172, 175, 267, 276, 425. 42S.
Iron pyrites, crystallized, artificial, 158,
Jamesonite, analysis of, 237.
Johnston (J. F. W.) on baryto-calcite, 373,
Jussieu (MM.) notice of, 152, 470.
Kane (Dr.) on pyroxylic spirit, 45, 116; on

the composition of thebaine, 387 ; on the

protochloride and terchloride of iodine,

430.
Keith (Rev. P.) on the classification of ve-

getablts, 37, 108.
Kelland (P.) on the transmission of light

and heat in uncrystallized media, 336.
Kiernan (F.). Copley medal awarded to,

212. '

Kinkajou, notice of the, 291.
Knight (T. A.) on the absorbent powers

of the roots of trees, &c., 488.
Koala, anatomy of the, 481.
Koba and Kob of Buffbn, 303.
Lassaigne (M) on the compound of albu-
men and bichloride of mercury, 420.
Latham (Dr.), notice of, 467.
Leach (Dr.), notice of, 151, 467.
Lead, peroxide of, voltaic condition of iron

as excited by, 425, 428.
Leveille (M.) on the hymenium of fungi,

492.
Liebig (M.) on an aetherial oil of wine, 417.
Light, new dioptric, 176; on the disper-
sion of, 221; experiment on the inter-
ference of, 364 ; transmission of, in un-

crystalized media, 336, 385.
Lime, carbonate of, its decomposition by

heat, 496.
Linnaean Society, 71, 223, 464.
Littrow (Prof.) on the projection of maps

and charts, 229 ; construction of the

hour-lines of sun dials, 229.
Lloyd (Prof.) on the propagation of light

in uncrystallized media, 385.
Lubbock (J. W.) on the tides, 381.
Lyell's(C.)address to the Geological Society

at the anniversary, Feb. 17, 308, 388.
MacCullagh (J.) on the laws of crystalline

reflexion, 42 ; on the laws of reflexion

from metals, 382.
MacGauley's (J. W.) reply to Dr. Ritchie,

130.
Macvicar ( Rev. J. G.) on the symmetrizing

power of the eye, 234.
Magnesia, hydrate of, 454,
Magnet, permanent, on the electric shock

and spark from, 280.
Magneto-electrical machines, 12, 65.
Maize, fossil, 323.
Mallet (R.) on the aurora borealis of Sept.

29, 75.
Man, physical development of, 197.
Manganese ore containing silver, 279.
Manna of Mount Sinai, 226.

508

INDEX.

Marquart (J. C), progress of phytoch©-

mistry, 247.
Marsh's test for arsenic, 353.
Marsupial animals, on the brain in, 222.
Martens (M.) on the decolorizing combi-
nations of chlorine, 155.
Martin ( W.) on a new species of the genus
Felis, 480; anatomy of the koala, 481.
Mathematics, 18, 28, 32, 35, 105, 121.
Matteucci (M. ), magnetic observations of

the aurora of Feb. 18, 494.
Mellitic acid, 159.

Mercury, compound of albumen and bi-
chloride of, 420.
Metals, their reduction by electricity, 154.
Meteorological observations, 79, 159, 239,

327, 423, 503.
Meteorological Table: — for Nov., 80;
December, 160; January, 240; Febru-
ary, 328; March, 424; April, 504.
Microscopes, solar and oxy-hydrogen, 184,

219.
Mineral veins, on, 394.
Mineralogy : — Zeagonite, Gismondin, Ab-
razite, Aricite and Phillipsite, 170;
Murchisonite, Moonstone, and the iride-
scent felspar from Fredricksvarn, 1 70 ;
analysis of tin pyrites, Tennantite,
Jamesonite, Augite and Amphibole,
236 ; on the intersection of crystalline
minerals, 278 ; on the identity of Bio-
tine and Anorthite, and on a new crystal
• of quartz, 368.
Minerals, organic forms of, 318.
Molecular action, 320, 355.
Monkey (Pithecia leucocephala of Geof-

froy St. Hilaire), 73.
Mossotti (M.) on molecular action, 320.
Mountains, on the ascent of, 261.
Mulder (M.) on the red and white oxide

of phosphorus, 499.
Miiller's (.Prof.) account of the reflex func-
tion of the spinal marrow, 51, 124, 187,
378.
MuUins (F. W.) on magneto-electrical
machines, in reply to Prof. Ritchie, 12;
on the construction of voltaic batteries,
63 ; on the action of electricity in voltaic
combinations, 281.
Murchison (R.I.) on a raised beach in

Barnstaple bay, 477.
Murphy (Rev. R.) on a new theorem in
analysis, 28 ; on rectangular forces, 105;
on the theory of analytical operations,
2J9.
Muscular effort required to ascend planes
of different inclinations, 261 ; muscular
fibre of animal and organic life, 377.
Newport(G.), Royal medal awarded to,214.
Newton's rings, on, 183.
Nicholson (P.), remarks on his rule for
the construction of the oblique arch, 167.
Jlitric acid, its action on iron, 133, 267,
276, 42.5, 428 ; on the causes of the neu-
trality of iron in, 172, 17J.
yitro&ulphuric acid, 48|>.

Noad (H. M.) on the peculiar voltaic con-

dition of iron, 276.
CEnanthic acid, 417, 422.
CEnanthic aether, 418.

Oil, asthereal, of wine, 417; oil which ac-
companies pyroxylic spirit, 48.
Optical phenomena of crystals, 218.
Orang-utans, specific distinctions of the,

295.
Organic chemistry, researches in, 45, 116.
Organic compounds, a new force acting in

the combinations of, 490.
Organic remains, 4, 137, 402.
Ornithology : — new species of ortyx, 287 ;
two new species of birds from New South
Wales, 287, 306 ; rare birds in the vici-
nity of Scarborough, 287 ; 'linamotis
Pentlnndii, 289; Psittacus Augustus
and Psitticus Guildingii, 289; Tamalia
bicincta, 290 ; Cursorius rufus, 290 ;
three-qnarter-bred pheasants, 292; birds
from Swan River, 293 ; new genus in the
group of wrens, 295 ; list of birds no-
ticed at Smyrna in the winter of 1835-6,
301 ; habits of the vulture, 479.
Owen (R.) on the brain of marsupial ani-
mals, 222 ; on the specific distinctions of
the orangs, 295.
Oxides and salts, their solubility in muriat©

and nitrate of ammonia, 95, 178, 333.
Painting in enamel, art of, 442.
Palaeontology, 318.
Parabola, on a property of the, 32, 35.
Peligot (M.) on camphor, 420.
Pelletier (M.) on the action of iodine on

the vegetable alkalis, 500.
Pelouze (M.) on an aeiluieal oil of wine,

417 ; on the action of presence, 489.
Per-iodic acid, properties of, 325.
Phosphorus, red and white oxide of, 499.
Phytochemistry, progress of, 247.
Pinas sylvestris, starch in the bark of, 249.
Platina, spongy, method of obtaining, 154,
Pond (J.), notice of, 146.
Porcelain earth, composition and origin of,

348.
Potassium, cyanide of, as produced in hot-
blast furnaces, 329.
Powell (Prof.) on the theory of the disper-
sion of light, 221.
Pyrophori, easy preparation of, 319.
Pyroxylic spirit, on, 45, 116.
Quartz, new crystal of, 369.
Rainey (G.) on magnetic reaction, 193.
Reade (J. B.) on producing achromatic
light in solar and oxy-hydrogen micro-
scopes, 185 ; on the solar rays that occa-
sion heat, and on the solar and oxy-hy-
drogen gas microscope, 219.
Rectangular forces, on, 105.
Rees ( G. O. ) on hydrate of magnesia, 454.
Reflexion, crystalline, laws of, 42 ; re-
flexion from metals, on the laws of, 382.
Refraction, double, on Fresncl's theory of,f
24.

INDEX.

509

R<'nw5ck (Prof.) on the height of the

Rocky mountains of North America, 73.

Review: — Solly on the Human Brain, 286.

Ritchie (Dr.), reply to IMr. Rainey, 57;

reply to the Rev. J. W. MacGaukyand

the Rev. N. J. Callan, 61 ; on Newton's

rings and the (ixed lines of the spectrum,

18S; on the velocity of sound in air,

and that resulting from theory, 220; on

the electric spark and shock from a per-

: nianent magnet, 280 ; reply to the Rev.

J. W. MacGauley, -162.
Rocky mountains of N. America, heights

of, 78.
Royal Institution, 317, 485.
Koyal Irish Academy, 382, 487.
Royal medals awarded to Sir J. Herschel

and Gecrge Newport, Esq., 213, 214.
Royal Society, 62, 141, 210, 376.
Rumker (C.) on the solar eclipse of May
, 15, 1836, 180.
Sabine (J.), notice of, 468.
Salts, their solubility in muriate and nitrate
of ammonia, 95, 178,333; on the con-
stitution of, 216; metallic, peculiar ac-
tion of iron upon solutions of, 267, 276.
Sap, ascent of the, 494.
Schrenbein (Prof.) experiments on a pe-
. culiar voltaic condition of iron, 133,
267, 425, 428 ; on Faraday's hypothesis
on the causes of the neutrality of iron in
nitric acid, 172.
Schomburgk ( R. H. ) on the tree from which
the Indians prepare the poison called
wooraly or ourary, 72 ; description of
the Pithecia leucocephala of Geoffroy
St. Hilaire, 73.
Schumacher (Prof.) on the imperial stand-
ard troy pound, 63.
•• Scientific Memoirs," notice relative to, 81.
Scolder (Dr.) on hills of gravel in Ireland

containing marine shells, 471.
Seals of Ireland, on the, 487.
Sedgwick (Prof.) on a raised beach in

Barnstaple bay, 477.
Shell, an artificial substance resembling,

201 ; new fossil shell, 239.
Siebold (Dr. Von) on a double-bodied in-
testinal worm, 253.
Silk, analysis of, 323.
Simla Morio, an orang of Borneo, 297.
Skey (F.) on the muscular fibre of animal

and organic life, 377.
Smith (J.) on changes in the relative level
of sea and land in the West of Scotland,
136.
Solar eclipse, 180, 230.
Solar rays that occasion heat, 219.
Sound in air or vapour, velocity of, 220.
Sowerby (J. De C.) on a new fossil shell,

239.
Spectrum, on the fixed lines of the, 183.
Spina bifida, on, 316, 486.
Spinal marrow, on the reflex function of
the, 51, 124, 187, 378.

Starch, 23.5 ; expcnments on, 247.
Steel, action of sulphurous acid on, 235.
Stokes (C.) on a petrified piece of wood

from a Roman aqueduct, 476.
Strickland ( H. E.), birds observed by him at
Smyrna in the winter of 18^5-3*6, 301 ;
ge(.logy of the western part of Asia Mi-
nor, 68 ; geology of the Thracian Bo8.»
phorus, 473.
Struve (Prof.) on the measures of double

stars, 229.
Strychnos toxifera, the tree from which the
Indians prepare the poison called woo-
raly, 72.
Sturgeon (W.) on the relative merits of
magnetic electrical machines and voltaic
batteries, 65.
Sugar, crystallized, from the juice of the

cocoa-nut palm, 77.
Sulphate of copper, voltaic battery charged

with, 244.
Sulphuric acid, anhydrous, its action on
some metallic chlorides, 157 ; analogy of
alcohol and indigo considered in their
combination with, 324.
Sulphurous acid, its action on steel, 235.
Sulphindylic acid, 324.
Sun, remarkable phenomenon that occurs

in eclipses of the, 230.
Sussex (H. R. H. the Duke of), address
delivered at the anniversary of the Royal
Society, 141 ; address on the delivery of
the Royal medal to Sir J. F. W. Her-
schel, 213.
Symmetrizing power of the eye, 234, 370.
Syngamus trachealis, 253.
Tabuloscriptive engine. 486.
Tall)ot (JH. F.), researches in the integral
calculus, 210; on the optical phenomena
of crystals, 218 ; experiment on the in-
terference of light, 364.
Taylor (J.) on manganese ore containing

silver, 279.
Taylor ( R.), notice relative to the " Scien-
tific Memoirs," 81.
Taylor (R. C.) on a vein of bituminous

coal in the island of Cuba, 163.
Tennantite, analysis of, 236.
Thebaine, composition of, 387.
Thompson (L.) on the solubility of me-
tallic oxides and salts in muriate of
ammonia, 179; on antimoniuretted hy-
drogen, 853.
Thomson (Dr. J.) on the interpretation of
formula in spherical trigonometrj-, 18;
formulae for the rectification of the
circle, 210.
Thomson ( Dr. R. D.) on tlie preparation

of boron, 419.
Tides, on the, 317, 380, 381.
Tin pyrites, analysis of, 236.
Trigonometry, spherical, on the interpreta-
tion of formulae in, 18.
Tungsten, on some compounds of, 322.
Undulatory theory, 24.

510

INDEX.

Ure (Dr.) on the modes of wanning and

ventilating apartments, 64.
Vegetables, on the classification of, .S7, 108.
Vegetation in a solution of arsenic, 324.
Veins, mineral, 394.
Velocity of sound in air or vapour, 220.
Ventilating and warming apartments, on

the modes of, 64.
Vision, experiment on, 234, 370.
Volcanos of Asia Minor, 70.
Voltaic action, artificial crystals bv, 171.
Voltaic batteries, 63, 65 ; new, 241 ;

charged with solution of sulphate of cop-
per, 244.
Voltaic combinations, action of electricity

in, 281.
Voltaic condition of iron, peculiar, 133,

172, 267, 276,425, 428.
Vulture, habits of the, 479.
Walton (Rev. W.) on the helm wind, 221.
Warming and ventilating apartments, modes

of, 64.
Watson (J.), an experiment in electricity,

326.
Weaver (Thos.) on the carboniferous se-
ries of New York and Pennsylvania, 365.
Welch (H.) on oblique bridges, 74.
Wellsted (Lieut.) on the manna of Mount

Sinai, and the dragon's blood tree and

aloe plant of Socotra, 226.
Westwood (J. O.), descriptions of new hy-

roenopterous insects, 440.
Wetherell (N. T.) on the fossils of the

London clay, an error in, 239.
Wheatstone (Prof.) on the thermo-electric

spark, 414.
Whewell (Rev.W.) on the tides, 317, 380.
Wilkins (Sir C), noUce of, 148.

Williamson ( W. C.) on the organic remain*
in the oolitic formations of the Yorkshire
coast, 137.

Willis (Prof.) on the tabuloscriptive engine,
486.

Wind, helm, on the, 221.

Wine, aethereal oil of, 417.

Wollaston medals, awarded to Captain P.
Cautley and Dr. H. Falconer, 306.

Worm, double-bodied intestinal, 253.

Wrottesley (Mr.), catalogue of the right
ascensions of 1318 stars, 227.

X. Voluntary sounds of insects, 327.

Xanthoinethilic acid, 488.

Young (J. R.), formulae for the summation
of infinite series, 121.

Young (J.) on a new voltaic battery, 241.

Zoological Society, £87, 479.

Zoology : — an undescribed ortyx, 287 j
birds from New South Wales, 287, 306 ;
rare birds in the vicinity of Scarborough,
287; Tinamotis Pentlandii, 289; Ta-
matia bicincta, 290 ; new species of
Cursorius, 290 ; notes on the kinka-
jou, 290 ; three-quarter-bred pheasants,
292 ; birds from Swan River, 293 ; notes
on some mammalia, 293 ; proposed new
genus in the group of wrens, 295 ; the
Sumatran and Bornean orang-utans,
295 ; birds from Asia Minor, 301 ; Ar.
gonauta, Linn., 303 ; the koba and kob
of Buffon, 303; fox of the Himalayan
mountains, 304 ; habits of the cuckoo,
305 ; habits of the vulture, 479 ; new
species of the genus Felis, 480 ; ana-
tomy of the koala, 481 ; on the seals of
Ireland, 487.

END OF THE TENTH VOLUME.

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