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RECORDS

GENERAI7 SCIENCE,

BY

ROBERT D. THOMSON, M. D.,

PHYSICIAN TO THE FORE STREET DISPENSARY, CRIPPLEGATE, AND LECTURER ON
CHEMISTRY IN THE BLENHEIM STREET MEDICAL SCHOOL.

WITH THE ASSISTANCE OF

THOMAS THOMSON, M.D.,F.R.S.L. & E.,F.L.S.,F.G.S.,&c.

REGIUS PROFESSOR OF CHEMISTRY IN THE UNIVERSITY OF GLASGOW.

VOL. I.

LONDON:

JOHN TAYLOR, 30, UPPER GOWER STREET,

Bookseller and Publisher to the University of London ; and

SOLD BY MACLACHLAN AND STEWART, EDINBURGH ; JOHN REID AND CO., AND RUTHER-

GLEN AND CO., GLASGOW; WAKEMAN, DUBLIN; KING AND CO., CORK ; GRAPEL,

LIVERPOOL ; WEBB & SIMMS, MANCHESTER ; AND BARLOW, BIRMINGHAM.

1835.

LONDON:
Printed by W. Johnston, 13, Mark Lane.

ADVERTISEMENT.

The First Volume of the Records of General Science
being now completed, it appears not unappropriate to take
a retrospect of its contents.

These may be classed under four heads :

1. Original communications. Of this class of papers the
volume contains no less than twenty eight ; three of which
are descriptive, upon a new plan, of calico-printing, one of
the most . important and beautiful manufactures in this
country. Eight are devoted to accounts of 12 minerals,
of 8 of which, viz., Thulite, Crucilite, Kirwanite, Bysluite,
Calcareo-sulphaie of Barytes, Baryto-calcite, Sulphato-car-
bonate of Barytes, Bi-calcareo Carbonate of Barytes, the
chemical composition has never been previously published ;
for with the exception of Thulite their discovery is for the
first time announced. The 3 remaining minerals are
Wollastonite, Gadolinite and Wolfram. In Gadolinite, an
earth has been detected which was not observed by the
only analyst who had previously subjected it to examina-
tion, although his results are received by many with
implicit reliance. In the same paper an elaborate exami-
nation of the salts of yttria and cerium is likewise detailed.
Two new fossil Crustacea are described in another original
communication, while two papers are devoted to an
interesting investigation into the subject of spirits, and
two into that of sound.

2. Papers and extracts from Foreign Journals. These
comprehend the subjects of Biography, Chemistry Minera-
logy, Geology, Botany, Physics, Natural History, Physio-
logy, Medicine, Statistics.

3. Analyses of Books. The object in this department

a 2

IV. ADVERTISEMENT.

has been as it ought to be in every review, to present to the
reader an outline of the work under consideration, more
especially, of its plan and of any new facts which it may
contain. This method has been extended to the Royal and
Linnean Societies, which appears preferable to inserting
papers at full length from the transactions of those Societies.

4. Under Scientific Intelligence are included such notices
and answers to questions, as are too brief to form distinct
papers. The reports of the Royal Institution lectures, which
are generally of great interest, although presented under
many disadvantages, will, it is hoped, be found upon? the
whole, to afford a pretty correct view of the facts and
arguments brought forward. The meteorological table
which falls under this head, is considered to be one of the
most complete and correct ever published in this country.

The intention of the Editor, although he is sensible of
many imperfections in it, has been to present his readers
with a book of facts. Whether he has succeeded or not,
he leaves others to determine. He cannot allow this
opportunity to pass, however, without noticing the cheer-
ing encouragement which he has received from men of the
highest distinction in Science ; and of thanking all those
who have hitherto supported him in his undertaking. He
trusts to their future assistance, being fully confident, that
the work will improve as it advances.

TABLE OF CONTENTS

No. I. — January 1835.

Page

Preface 1

I. On Calico- Printing. By Thomas Thomson, M.D., &c. . . 3

II. A Journey in Spain. By M. F. Le Play ...... 19

III. On Respiration. By Thomas Thomson, M.D., &c. . . 27

IV. &n the Changes produced in the composition of the Blood

by Repeated Bleedings. By Thomas Andrews, Esq. . 31

V. History and Analysis of the Vanadiate of Lead. By Robert

D. Thomson, M.D , .... 34

VI. Transmission of Heat through different Solid and Liquid

. Bodies. By M. Melloni 45

VII. Products of the Distillation of Pit Coal. By F. F. Runge 47

VIII. On Pittacal, (a New Dye-Stuff) 54

IX. On the Acid Nature of the Blood, and the Distinction

between Arterial and Veinous Blood. By R. Hermann 55

X. Researches on the Blood. By L. Gmelin and F. Tiedemann,

assisted by E. Mitscherlich 56

XI. On the Magnetic Intensity of the Earth. By C. Hansteen 60

XII. Analyses of Books. Traite Experimental de Electricite

et du Magnetisme et de leurs rapports avec les Pheno-
menes naturels. Par M. Becquerel, torn, i 66

XIII. Scientific Intelligence.

1. Method of destroying Mice in their Lurking Places . 76

2. Fresh Water Formation in Greece, with Lignites. By

M. Theodore Virlet 77

3. Oil Extracted from the Spirit of Wine of Potatoes. By

M. J. Dumas ib.

4. Mode of detecting some Organic Acids. By H. Rose 78

5. Iron Mine of Rancie. By M. Dufrenoy ib.

6. Geological Position of the Campan Marble. By M.

Dufrenoy * 79

7. Effect of Gases on Vegetation. By M. Macaire . . ib.

8. Notices of the Natural History of Egypt in 1832. By

M. Roux . ib.

9. Summary of a Meteorological Register kept at Eccles,

Berwickshire. By the Rev. James Thomson ... 80

No. II. — February.

I. Biographical Account of Alexander Volta. Bv M. Arago . 81

II. Chemical Analysis of Thulite. By Thos. Thomson M,D, cS:c. 92

V1 CONTENTS.

- PAGE

III. Analysis of Arden Limestone. By Thomas Thom-

son, M.D., &c 96

IV. Notice of Some Recent Improvements in Science. By

the Editor 97

Acoustics 98

Electricity 99

Magnetism 102

Pneumatics 103

Chemistry 108

V. On a Deposit of Recent Marine Shells at Dalmuir, Dum-

bartonshire. By Thomas Thomson, Esq 131

VI. Account of some Fossil Crustacea which occur in the Coal

Formation. By John Scouler, M.D., &c 136

VII. Chemical Analysis of Crucilite, a new form of Peroxide

of Iron. By Robert D. Thomson M.D 142

VIII. Analyses of Books. Traite Experimental de Electricite,

&c, torn, ii 144

IX. Scientific Intelligence.

1. New Expeditions of Discovery ....... 155

2. Improvement in the Arts 159

3. On the Native Country of Maize ib.

4. Hydrate of Iron an Antidote for Arsenious Acid . . ib.

5. New Pharmaceutical preparations 160

6. Register of the Fall of Rain during 1834, kept at the

Macfarlane Observatory, Glasgow University . . . ib.

No. III.— March.

I. On Calico- Printing, {continued). By Thomas Thomson,

M.D., &c. {concluded) 161

II. Researches into the Number of Suicides and Murders com-

mitted in Russia, in 1821-22. By M. C. T. Hermann 173

III. Notice of Some Recent Improvements in Science, (con-

tinued) 184

Chemistry ib.

Botany 216

IV. Analysis of Kirwanite. By Robert D. Thomson, M.D. . 219

V. Chemical Analysis of Wollastonite. By Robert D. Thom-

son, M.D 220

VI On Spirits. By Andrew Steel, M.D 222

VII. Analyses of Books. Philosophical Transactions for 1834,

Part ii 228

VIII. Scientific Intelligence 236

1. Melloni's Experiments on Heat ib.

2. Microscopical objects 239

3. Isinglass ' ib.

4. Prize of the Imperial Academy of Sciences of St.

Petersburg for 1836 ib.

Meteorological Journal for January 1835. By the Rev.

J. Wallace 240

CONTENTS. Vll

PAGE

No. IV.— April.

I. Biographical Account of M. Desfontaines. By Aug. Pyr

DeCandolle . . 242

II. An Abstract of some Researches on the Repulsion produced

between Bodies by the Action of Heat, with Additional
Observations. By the Rev. Baden Powell, &c. . . 250

III. On Spirits. By Andrew Steel, M.D. (continued) . . 255

IV. Notice of Some Recent Improvements in Science . . . 265

Mineralogy ib*

Meteoric Stones 279

Mineral Waters 681

V. On Dysluite. By Thomas Thomson, M.D., &c 285

VI. Sketch of the Geology of the Bombay Islands. By Robert

D. Thomson, M.D 291

VII. Analyses of Books 304

Philosophical Transactions for 1834, Part ii. (concluded) . ib.

VIII. Scientific Intelligence 313

1. Employment of Gypsum in Agriculture ..... ib.

2. Royal Institution. — Comparison of the Newtonian and

Undulatory Theories of Light 315

3. Pharmaceutical Preparations 318

4. Muriate of Ammonia in some Minerals 319

5. Peroxide of Manganese ib«

Meteorological Journal for February. By the Rev. J.

Wallace 320

No. V.— May.

I. On Calico-Printing, (continued.) By Thomas Thomson,

M.D., &c 321

II. Sketch of the Geology of the Bombay Islands. By Robert

D. Thomson, M.D. (concluded) 330

III. Geology of Estramadura and the North of Andalusia. By

M. F. Le Play 341

IV. Experiments and Observations on Visible Vibration. By

Charles Tomlinson, Esq 358

V. On the Adjustment of the Eye to Distinct Vision at Diffe-

rent Distances. By John Walker, Esq 368

VI. Account of some New Species of Minerals containing

Barytes. By Thomas Thomson, M.D., &c 369

VII. On Human Saliva. By C. G. Mitscherlich .... 375

VIII. Analyses of Books 384

1. The Transactions of the Linnean Society of London,

Parti. 1834 . ib.

2. Facts, laws, and Phenomena of Natural Philosophy,

Translated from the French of Professor Quetelet of
Brussels, with Notes. By Robert Wallace . . . 392

3. Proceedings of the Berwickshire Naturalists' Club . 393

4. Abstract of a Paper on the Refraction and Polarization

of Heat. By Professor Forbes 394

Vlll CONTENTS.

PAGE

IX. Scientific Intelligence 396

1. Floorcloth Manufactory ib.

2. Present State of Jerusalem 397

3. Manufacture of Pens. By Dr. Faraday ib.

Scientific Books in the Press and on Hand .... 399
Meteorological Journal for March. By the Rev. J.

Wallace . 400

No. VI.— Jane.

I. Biographical Notice of M. Chaptal 401

II. Chemical Analysis of Gadolinite, together with an Ex-

amination of some of the Salts of Yttria and Cerium.
By Thomas Thomson, M. D., &c, and Andrew Steel,
M. D 403

III. Examination of Lymph, Blood, and Chyle. By John

Miiller, M. D., &c 424

IV. Experiments and Observations on Visible Vibration. By

Charles Tomlinson, Esq ,433

V. On the Accidental Colours of certain solutions on Mer-

cury. By Charles Tomlinson, Esq 439

VI. On Malt. By Robert D. Thomson, M. D. 441

VII. Analysis of Wolfram. By Mr. Thomas Richardson . . 449

VIII. Erysipelas of the Extremities successfully treated by
Mechanical Pressure. By James Allan, Esq. . . . 452

IX. On the mean Temperature of the Ground at Various

Depths. By F. Rudberg 456

X. Scientific Intelligence 458

1. Ashmolean Society of Oxford . ib.

2. Royal Institution 464

3. Comparison of the two Theories of Electricity . . ib.

4. Dr. Lardner on Halley's Comet 465

5. Mr. Wheatstone on Speaking Machines 469

6. Metropolis Soft Spring Water Company 470

7. Address to Meteorologists 471

8. Postscript to Mr. Walker's paper on the Adjustment of

the Eye, &c ib.

9. Optical Experiment 472

10. Prevention of Dry Rot by Corrosive Sublimate . ib.

11. Mode of Preserving Iron and Steel from Rusting . . 473

12. Communication by Egypt to India 474

13. Botanic Garden in Japan ib.

14. Phloridzin, a New Substance 475

15. Greatest Ascents in the Atmosphere ib.

16. Diamonds in Africa . ,. ib.

Meteorological Journal. By the Rev. J. Wallace 476

Index 477

PREFACE

i

The utility of periodicals, in contributing to the rapid
progress of Science and Literature, is sufficiently evinced
in the simple fact, that their origin is but of recent date.

It is true, that some have endeavoured to discover their
existence among the Romans, from a few obscure pas-
sages of Ovid and Tacitus. There can be little hesitation,
however, in concluding, that the allusions of these authors
refer not to publications analogous to our periodicals,
but to incomplete or unfinished works, corresponding
with the first editions of books in the present day.

The first periodical appears to have been published in
the reign of Elizabeth in 1588, under the name of the
" English Mercurie," an "original number of which, is
preserved in the British Museum. Until the reign of
James II., periodicals Were warmly encouraged, when
bigotry and politics usurped their place.

Towards the end of the sixteenth, and during the course
of the seventeenth centuries, numerous Scientific bodies
were formed throughout Europe, for the purpose of culti-
vating Science, and of disseminating the results of their
labours. Accordingly, the Royal Society of London,
commenced the publication of its transactions in 1665,
and its example was followed in 1699, by the Royal
Academy of Sciences of Paris. The succeeding century,
gave rise to many periodicals in Britain, which were sig-
nally effective, in spreading that taste for Science and
Letters, which has so long distinguished this great
country.

vol. I. B

II PREFACE.

A few years have only elapsed, since not less than six
Scientific Journals, were published in Great Britain ;
these have now dwindled into two, one of which, is
published monthly in London, and the other quarterly, in
Edinburgh.

The pages of the former, are chiefly devoted to original
communications, while the latter, is principally conspicu-
ous for its details of Natural History. There seems,
therefore, to be required a separate periodical, which may
afford intelligence not only of what is transacting at home,
in reference to a more extended field of Science, but like-
wise of the researches of those, who are labouring in the
same great cause abroad. With this object in view, the
Records of General Science has been projected ; and with-
out detaining our readers, it is only necessary to state,
that as utility is the great principle to be followed in con-
ducting it, no pains shall be spared on the Editor's part,
in endeavouring to collect all important new facts, which
may be ascertained both at home and abroad — more espe-
cially, in the Sciences of Chemistry, Mineralogy, Geology,
Natural History, Physics, and the Arts. The powerful
assistance, of the Editor's relation, Dr. Thomson, of
Glasgow, whose great knowledge and experience, in con-
ducting the Annals of Philosophy, one of the most efficient
Journals, of this, or any other country, under his manage-
ment are well known, cannot fail to be considered as a
high recommendation. And it is hoped, from the favour-
able manner in which the project has been received, by
many distinguished cultivators of Science, that general
support may be extended to the publication, in order that
the Editor may be enabled to afford sufficient time for
such an arduous undertaking.

RECORDS

OF

GENERAL SCIENCE

JANUARY, 1835.

Article I

On Calico- Printing. By Thomas Thomson, M. D., F. R. S.,
L. and E. &c, Regius Professor of Chemistry in the
University of Glasgow.

Calico-printing is the art of applying one or more
colours to particular parts of cloth, so as to represent
leaves, flowers, &c, and the beauty depends partly on the
elegance of the pattern, and partly upon the brilliancy
and contrast of the colours. The process is not confined
to cotton cloth, as the term calico-printing would lead us
to suppose. It is applied also to linen, silk, and woollen
cloth ; but as the processes are in general the same, I
shall satisfy myself with describing them as applied to cot-
ton, because it is with them that I am best acquainted.

The general opinion is, that this ingenious art originated
in India, and that it has been known in that country for a
very long period. From a passage in Pliny, who probably
composed his Natural History about the middle of the
first century of the Christian Era, it is evident that calico-
printing was understood and practised in Egypt in his time,
but unknown in Italy.

" There exists in Egypt," says he, " a wonderful method
of dyeing. The white cloth is stained in various places,

b2

4 Dr. Thomas Thomson on [Jan.

not with dye-stuffs, but with substances which have the
property of absorbing (fixing) colours. These applications
are not visible upon the cloth ; but, when the pieces are
dipt into a hot caldron containing the dye, they are drawn
out an instant after, dyed. The remarkable circumstance
is, that though there be only one dye in the vat, yet dif-
ferent colours appear on the cloth ; nor can the colours be
again removed." # That this description of Pliny applies
to calico-printing, will be evident to every person who will
take the trouble to read the account of the processes which
we are going to give.

The colours applied to calico in India, are beautiful and
fast. The variety of their patterns, and the great number
of colours which they understood how to fix on diffe-
rent parts of the cloth, gave to their printed calicoes a
richness and a value of no ordinary kind. But, their pro-
cesses are so tedious, and their machinery so clumsy, and
they could be employed only where labour is so cheap
as to be scarcely any object to the manufacturer. It is
little more than a century and a half since calico-printing
was transferred from India to Europe, and little more than
a century since it began to be understood in Great Britain .
The European nations who have made the greatest progress
in it, are Switzerland, France, especially in Alsace, some
parts of Germany, Belgium, and Great Britain.

In Europe, the art has been in some measure created
anew. By the application of machinery, and by the light
thrown on the processes by the rapid improvements in
chemistry, the tedious methods of the Indians have been
wonderfully simplified ; while the processes are remarkable
for the rapidity with which they are executed, and for the
beauty and variety and fastness of the colours.

I propose in this paper to give a sketch of the diffe-
rent processes of calico-printing, such as they are at present
practised by the most skillful printers in Lancashire, and in
the neighbourhood of Glasgow .f

* Plinii Hist. Nat. lib. xxxv. c. 11.

t I think it right to state, that for all my knowledge of Calico-Printing, I am
indebted to my friend, Mr. Walter Crum, Calico-Printer, in the neighbourhood
of Glasgow. With a liberality, for which I feel greatly indebted to him, he has
explained his processes to me without mystery or reserve.

1835.] Calico- Printing. 5

PRELIMINARY PROCESSES.

The cotton cloth, after being woven, is subjected to seve-
ral preliminary processes, before it is fit for calico-printing.
It will be sufficient merely to allude to them. They are
singeing and bleaching. The singeing is intended to remove
the fibres of cotton which protrude on the surface of the
cloth. This is done, by passing the cloth rapidly over the
surface of a red-hot iron cylinder, which burns off all the
hairs, or protruding fibres of the cotton, without injuring
the cloth. Of late years, an ingenious coal-gas apparatus
has been substituted for the red-hot iron, both in Manches-
ter and Glasgow.

The bleaching of cotton consists essentially of four dif-
ferent processes. 1. The cloth is boiled with lime and
water; it is then washed clean. 2. It is steeped for some
hours in a solution of chloride of lime, or bleaching powder,
as it is usually called. From this steep also it is washed
clean. 3. It is boiled in a solution of American potash.
After the duty was taken off common salt, carbonate of
soda (and consequently caustic soda) became so cheap,
that it gradually took the place of pearl ashes * 4. The
cloth is now almost bleached; it requires only to be
steeped in water holding in solution about four per cent,
of sulphuric acid, to complete the process.

Cotton cloth at an average, takes about two days to
bleach. But, when there happens to be occasion for greater
dispatch, it is no uncommon thing to complete the bleach-
ing and callendring in twenty- four hours.

PRINTING.

There are two modes of printing, namely, block-printing,
and cylinder-printing. The former has been practised from
time immemorial; the latter is a modern invention, and
originated, probably, after the introduction of the art of
printing into Great Britain.

The block is a piece of sycamore, (or, more commonly, a

* An impure Soda ash is now very generally used by Bleachers. For,
as every hundred pounds of crystallized carbonate of Soda contains 62£ of
water, the expense of carriage is more than double, and although the form indi-
cates in some measure the purity of this salt, every Bleacher knows how to
estimate the value of the drier preparation.

6 Dr. Thomas Thomson on [Jan.

fir board, on which a piece of sycamore is glued) on which,
the pattern intended to be printed on the cloth is cut.
The parts which are to make the impression, are left pro-
minent, while the rest of the block is cut away ; just as is
practised for wood engravings. When the pattern is too
complicated, and the lines too fine to be cut in wood, they
are made by means of small pieces of copper, drawn out
into narrow ribbons of the requisite fineness ; these are in-
geniously driven into the block, and the intervals are filled
up with felt. Great patience and ingenuity are displayed
in making these blocks for use, and calico-printers are
under the necessity of keeping a number of workmen, at
high wages, for that express purpose.

The inventors and drawers of the patterns, constitute
another class of ingenious artists, in the pay of the calico-
printers at high wages.

The cylinder is a large cylinder of copper, about a yard
in length, and four or Hve inches in diameter, upon which,
the pattern to be printed on the cloth is engraved. This
cylinder is made to revolve, and press against the cloth,
taking up the mordants, or colours to be printed on the
cloth as it revolves. By this ingenious contrivance, two
or even three different colours, are printed on the cloth at
once, and the printing proceeds, without interruption, till
a whole piece, or indeed, any number of pieces attached
to each other are printed.

Another method of printing is almost the same as copper-
plate printing. The patterns is engraved upon a flat copper
plate, a yard or more square. Upon this plate, the colour
or mordant to be applied, is spread. It is then pulled. As
it passes along, an elastic steel plate, called a doctor, takes
off' all the colour, except that which fills the engraving.
Being pressed against the cloth in the act of pulling, it
prints upon it either in mordants or colours, as may be
the impression of the pattern.

Whether the printing is applied by the block, the cylin-
der, or the flat plate, the treatment of the goods is nearly
the same.

Most commonly, the printing process is employed to fix
the mordants upon the cloth, which is afterwards dyed in
the usual way. Those parts only retain the colour which

1835.] Calico- Printing . 7

have imbibed the mordant, while the other parts of the
cloth remain white. Sometimes acids, or other substances,
are printed on cloth already dyed, to remove the colour
from certain portions of jt which are to be left white, or to
receive some other colour.

Occasionally, substances are printed on cloth before it is
dipt into the indigo vat, to prevent the blue colour from
becoming fixed on those parts to which they are applied.
Substances possessed of these properties are called resist
pastes.

It is a very common practice to communicate mordants
and colouring matters to cloth at the same time.

We must give a sketch of the different substances thus
applied, before proceeding to detail the different processes.

I. MORDANTS.

The term mordant, is applied by dyers to certain sub-
stances with which the cloth is impregnated before it is
dyed, otherwise the colour would not fix, but would dis-
appear on washing or exposure to the light. The name
was given by the French dyers, (from the Latin word mor-
dere, to bite,) from a notion entertained by them that the
action of mordants was mechanical, that they were of a
corrosive, or biting nature, and served merely to open the
pores of the cloth, into which the colouring matter might
insinuate itself. It is now understood that their action is
chemical. They have an affinity to the cloth, which causes
them to adhere to it ; while the colouring matter has an
affinity for, and adheres to the mordant.

The usual mordants employed by the calico-printer, are
the three following : —

1. Alumina, or the alum mordant. This mordant is made
by dissolving alum in water, and adding acetate of lime to
the solution. The liquid has a specific gravity of 1*08,
and contains about as much alum undecomposed, as the
liquid can hold in solution. For particular purposes,
calico-printers make a mordant by mixing three parts of
acetate of lead with four of alum. This mordant consists
of a mixture of acetate of alumina and alum ; for, about a
third part of the alum remains undecomposed.

When cloth is impregnated with this mordant, such is

8 Dr. Thomas Thomson on [Jan.

the affinity of the alumina for the cloth, that the acetate of
alumina, and even a portion of the alum, are decomposed,
and the particles of alumina adhere to the fibres of the cloth
so firmly that they cannot be removed by washing.

In order to determine the quantity of alumina fixed on
on the cloth by the aluming process, I got a quantity of
the cotton cloth that was to be dyed Turkey-red ; 1000
grains of this cloth were burnt, and the ashes being re-
served, and subjected to a chemical analysis, were found to
contain 0*4 grain of alumina; 1000 grains of the same
cloth after being dyed Turkey-red, and of course, impreg-
nated with the alum mordant, were treated in the same
way. The alumina obtained amounted to 8 grains. The
length of a piece of this cloth, weighing 1000 grains, was
1 yard 5§ inches, and its breadth 33 inches. Thus, a piece
of cloth, amounting to 1386 square inches, or rather, 2772
square inches, (as both sides of the cloth had been equally
subjected to an aluming process) had combined with 7*6
grains of alumina ; or every square inch of the cloth had
combined with 0*0027 grains (^th of a grain nearly) of
alumina.

1000 grains of the same cloth were dyed the palest
shade of Turkey-red usually given to cloth. When burnt,
the ashes were found to contain 0*8 grain of alumina.
Subtracting the 0*4 grain of alumina belonging to the
cotton fibres, there remains 0*4 grain for the quantity
communicated during the aluming process. In this case,
every square inch of surface of the cloth had combined with
0-00012 grain of alumina, or less than g^th of a grain.
Yet this quantity of alumina small as it is, was essential
to the permanence of the dye. For, when unalumed cloth
was dyed with madder, the colour was easily washed out
with water.

When cloth to be dyed red is impregnated with this
mordant, it is not thickened. When applied only to par-
ticular parts of the cloth, by the block or cylinder, it is
thickened with flour, qr calcined starch, or gum Senegal,
according to the nature of the style of work.

2. Oxide of tin. Perchloride of tin is very much used
as a mordant. The colouring matter is previously mixed
with it, and both are applied at once. Such applications

1835.] Calico- Printing. 9

are usually called chemical colours.* The mixture is allowed
to dry on the cloth, which is then merely washed with
water. When colours are applied in this way they are
easily altered by soap, exposure to the light, &c. Hence,
in common language, a chemical colour means a fugitive
colour. The colours produced in this way, are pink from
Brazil wood, peach wood, and cochineal ; purple from log-
wood, and yellow from Persian berries.

Perchloride of tin is much used in another common pro-
cess of calico-printing, known technically, by the apella-
tion of steam colours. It is decomposed and converted
into stannate of potash. The whole piece of cloth is im-
mersed in the liquid containing the stannate of potash, and
dried. The peroxide of tin is then deposited on the cloth,
by immersing the piece in a solution of sal ammoniac, or sul-
phate of magnesia ; but most commonly, in a very weak
solution of sulphuric acid. The different colouring matters,
previously thickened with starch, are then printed on the
cloth, and the whole subjected to the action of steam. By
the joint action of moisture and heat, a combination takes
place between the colouring matter and the oxide, which is
thus rendered insoluble. And no considerable quantity of
water is ever present to carry off the colouring matter, be-
fore it has .combined with the mordant.

3. Peroxide of iron. — This metallic oxide is much used as
a mordant. It is employed in the state of acetated pro-
toxide of iron, formed by dissolving iron in pyrolignic acid.
Within a few days after it has been applied to the cloth,
especially if exposed to a moist atmosphere, it loses its acid,
and the iron becomes peroxidized.

Acetate of iron, of the specific gravity 1*05 gives a black,
with madder. Various shades of purple are obtained by add-
ing different portions of the mordant and dye-stuffs. Diffe-
rent shades of red, from brown, red, to pink, are obtained in
the same way, substituting the alum mordant of various
strengths for the iron. Chocolates are got by mixing the

* A very general error prevails with regard to Chemical colours, that it is the
mode of applying them which renders them fugitive. It is, because Chemical
colours are made with changeable materials, that they are more easily acted on
than madder colours. Brazil pink for instance, is equally acted upon by light
and soap when dyed.

10 Dr. Thomas Thomson on [Jan.

aluminous and iron mordants, and then dyeing with
madder.

Indigo, oxide of manganese, catechu, &c. are colours per
se, and therefore, require no mordant.

II. DISCHARGERS OF COLOURS.

Most colours are fixed to the cloth by mordants ; or if
they be metallic oxides, they retain their affinity only at a
particular state of oxidizement. # Thus madder is fixed
by alumina, and cochineal by means of oxide of tin. Man-
ganese adheres to the cloth only when in the state of
sesquioxide, and is washed away by water the moment it is
converted into protoxide. Hence, when the printers wish
to discharge a colour from cloth, they employ something
that will dissolve the mordant, or which will deoxidize the
oxide, or colouring matter, if no mordant be present. The
dischargers are either acids, or substances having a strong
affinity for oxygen ; the former being employed to dissolve
the mordants, and the latter to deoxidize the oxides. The
chief of these are the following : —

1 . Citric acid is much used to dissolve alumina, and per-
oxide of iron, and thus to prevent the formation of colour
on particular parts of the cloth, by removal of the mordant,
which would otherwise produce them. It is obtained by
evaporating lemon juice, and thickening it with gum-sene-
gal for the cylinder, or with gum and pipe-clay for the
block. Its action is occasionally assisted by bisulphate of
potash, or sulphuric acid.

• Sometimes the citric acid is first printed on white cloth,
and afterwards the aluminous or iron mordant is applied
slightly thickened. It is dried immediately to prevent the
swelling of the acid figures. At other times, the mordants
are first applied, and the acids printed over them.

In both cases, the goods are afterwards passed through
hot water, containing cow dung, and well washed before

* Almost every thing which can he applied to cloth, in a state of solution, and
which becomes afterwards insoluble in water, either by precipitation, or spon-
taneous decomposition, sticks to the cloth when it is washed. Water, therefore,
does not remove protoxide of Manganese, and the protochloride of tin alluded to
at the conclusion of this section, as a means of removing the sesquioxide or
peroxide of Manganese, not only takes away their oxygen, but converts them
into a soluble chloride.

1835.] Calico- Printing. 11

they are dried. This removes the mordants from all those
parts to which the acid has heen applied, which of course,
remains white after the cloth is dyed.

2. Tartaric acid thickened with gum, is applied by the
block, or cylinder, to cloth previously dyed Turkey-red.
It is then passed through an aqueous solution of chloride
of lime. The acid disengages chlorine from the chloride,
which of course, destroys the colour of those parts to
which it had been applied, while all the other parts of the
cloth retain their red colour. When oxide of lead is de-
posited on the cloth, along with the acid, and the cloth
after passing through the aqueous solution of the bleach-
ing-powder, is passed through an aqueous solution of
bichromate of potash. The parts that would have re-
mained white, are converted into a fine yellow. This
beautiful process is not confined to Turkey- red.

3. Protochloride of iron is used to discharge the manga-
nese brown, and substitute a buff. This it does, by de-
priving the manganese of oxygen, and thus rendering it
soluble : (the manganese is made soluble by conversion
into chloride of manganese) while the protochloride of iron,
being converted into perchloride, deposites peroxide of iron
on the cloth, which produces the characteristic buff or
orange colours of that oxide.

Sulphate of iron is used in a variety of ways. It de-
oxidizes the indigo in the indigo vat, and renders it soluble
in lime-water. It produces gold, buff, 8fc. colours, and
makes a good chemical black with logwood.

4. Protochloride of tin, when applied to cloth dyed brown
by the sesquioxide of manganese, immediately deoxidizes
it, discharges the colour, and leaves the part white. If it
be mixed with Brazil wood, or cochineal, it discharges the
manganese, but leaves a pink. When mixed with logwood,
it leaves 'djmrple ; and when with Prussian blue, a blue.

To produce a yellow upon manganese brown, chloride of
tin is mixed with sulphate of lead. This mixture thick-
ened with roasted starch, is printed on the manganese
brown. As soon as it is dry, the manganese being reduced
to the state of chloride may be washed off; but the sulphate
of lead adheres to the cloth, in consequence of an affinity
between them. The cloth being now limed, and passed

12 Dr. Thomas Thomson on [Jan.

through a solution of bichromate of potash, those parts
which contain the oxide of lead are dyed a beautiful yellow.
Chloride of tin is capable also of removing peroxide of
iron from cloth, by reducing it to chloride, as it does the
sesquioxide of manganese. For this purpose it is sometimes
printed on a deep colour, composed of peroxide of iron and
quercitron yellow. The protochloride of iron is formed
and washed away, while the oxide of tin remaining, con-
stitutes a mordant for the quercitron. Thus the parts to
which the tin was applied become yellow.

Protochloride of tin is also employed occasionally, to
discharge the orange, consisting of dichromate of lead
from the cloth. This it does by reducing the chromic
acid to protoxide. But as the green oxide of chromium
still continues fixed, the discharged parts do not assume a
good white colour. But this does not much affect the blue
and purple colours substituted for the orange, by mixing
the tin with Prussian-blue, or with logwood.

When protochloride of tin is decomposed by carbonate
of soda, protoxide of tin is obtained. This protoxide is
used along with potash, to render indigo soluble. The
protoxide deoxidizes the indigo, and the potash dissolves
the yellow base. It is then applied to the cloth in the way
that will be explained afterwards.

III. RESIST PASTES.

These are substances which have the property of restor-
ing the blue colour to dissolved indigo, and thus, of pre-
venting it from becoming fixed on those parts to which the
resist-pastes have been applied. Any substance which has
the property of readily parting with oxygen, answers this
purpose. Sulphate of copper, or any salt containing black
oxide of copper, when put into the indigo vat, instantly
revives the indigo, by communicating oxygen to it. The
hydrated black oxide of copper has the same effect, and so
have the sesquioxide and deutoxide of manganese.

The calico-printer's indigo vat is a very deep large vessel
filled with water, into which indigo, sulphate of iron, and
an excess of lime are put. The lime decomposes the sul-
phate of iron, and the disengaged protoxide of iron coming
in contact with the indigo at the bottom of the vat, deprives

1835.] Calico- Printing. 13

it of an atom of oxygen, and thus renders it capable of com-
bining with the lime, and of forming a compound which
dissolves in water, and forms a yellow liquid. Where this
solution is in contact with the atmosphere, the indigo is
revived, assumes its blue colour, and loses its solubility.
Hence, the blue scum which always covers the surface.
But this scum, in some measure, protects the rest of the
vat. When cloth is dipt into this vat it comes out yellow.
But from the exposure, the indigo gradually absorbs oxy-
gen and becomes blue. The cloth at first, from the mix-
ture of the blue and yellow, has a green colour, which
slowly deepens into blue. But if, to any parts of the cloth
before it be dipped into the vat, something has been applied
which has the property of giving out oxygen to the indigo ;
all the indigo which would be imbibed by these parts is
revived, before it comes in actual contact with the cloth ;
and, in the revived state, it is incapable of combining
chemically with the cloth, but may be easily washed off.
Hence, the parts covered by resist-pastes remain white.

The following are the principal resist-pastes used by
calico-printers :

1. Blue paste, or vitriol paste consists of a mixture of
sulphate and acetate of copper, and the solution is thick-
ened with gum-senegal and pipe-clay for the block, and with
flour, for the cylinder. When the cloth on which this
paste has been printed is dipt into the indigo vat, the in-
digo is revived before it has time to reach the surface of
the cloth. After dyeing, the piece is passed through weak
sulphuric acid, to remove the oxide of copper which has
been precipitated on it.

2. Mild paste consists of sulphate of zinc, gum, and
pipe-clay. It is used along with colours which copper would
injure, or which would be destroyed by immersion in sul-
phuric acid. It resists a pale blue, and the removal of
the oxide of zinc by an acid, is not necessary, as it is when
copper has been employed

Sulphate of zinc, as well as all the other metallic salts
and all the acids, precipitates indigo from its solution in
lime. It does not revive the indigo like the salts of copper ;
but when the base of indigo is precipitated, it is not so
readily fixed as when in a state of solution. The oxide of

14 Dr. Thomas Thomson on [Jan.

zinc with the gum and pipe-clay, acts mechanically in
keeping it at a distance.

3. Red paste consists of the alum mordant already de-
scribed, mixed with acetate of copper, gum, and pipe-clay.
It resists pale blues, and the alumina remains upon the
white portions of the cloth, to be afterwards dyed red, with
madder or yellow by quercitron bark.

4. Neutral paste is a name given by printers, to a com-
pound of lime juice, sulphate of copper, gum, and pipe-
clay. It resists during a short dip in the blue vat ; and
the lime juice gives it the property of remaining white
when the piece is dyed in madder, even when the preced-
ing red paste goes over it. This acid also prevents the lime
of the blue vat from precipitating copper upon the cloth,
which would cause the parts to assume a deep brown tinge
when dipt into the madder vessel.

5. Chrome yellow resist paste consists of a mixture of a
salt of copper, to resist the blue vat with a salt of lead, to
produce a yellow with bichromate of potash, after having
been dyed in the blue vat.

The preceding observations were necessary, to give the
reader an idea of the various processes, followed by the
calico-printers, and with the rationale of them. I shall now
proceed to explain the different colours. And both the
simplest and most intelligible method of proceeding seems
to be, to place pieces of printed calico before the eyes of the
reader, and describe the way in which the colours on them
have been produced. We shall begin with the simplest
colours, and proceed gradually to more^omnlex onps

1. Madder Red. — The alum mor-
dant described above, is made into a
paste, and printed on the cloth by
the cylinder. After being dried and
exposed in a warm room, till the
alumina has had time to leave the
acid with which it was united, and J
combine with the cloth, it is passed through a hot mixture
of cow's dung and water. It is then washed in cold water,
and agitated a second time in the same hot mixture. After
being thus freed from all soluble or loose matter, it is dyed
in madder. This process consists in the exposure of the

1835.]

Calico- Printing .

15

cloth to the action of madder, suspended in water. In con-
sequence of the very sparing solubility of the colouring
matter of that root, and the difficulty of applying it equally
to all parts of the cloth, the process requires to be con-
ducted slowly, and the heat to be very gradually raised. The
purest portion of the colouring matter being first given out
by the madder, the degree of heat is varied, according to
the fineness of the colour we desire to obtain.

After dyeing, those parts of the cloth intended to be
white, are always, more or less, tinged with the madder,
and much pains are necessary to restore their purity. For
this purpose, boiling with bran, or with soap, exposure to
light upon the grass, clearing with chloride of lime, or
other substances, which have the property of dissolving or
destroying this colouring matter, with repeated wash-
ings in cold water, are all resorted to according to
circumstances. And several of these operations have the
additional effect of brightening the red, by abstracting a
brownish matter, which always combines with the alumina,
at the same time with the red colouring matter.

2. Madder Purple. — The iron mor-
dant thickened in the same way as
the alum mordant, is similarly ap-
plied. The cloth is then exposed to ..■ I
the air for a few days, and the iron |
fixes itself on the cloth in proportion
as it becomes peroxidized . The piece
is then cleaned and washed as described lrrxne last proc
dyed in madder, and cleared in the same way as in the red
just described. The depth of the purple depends upon the
strength of the iron mordant. If its specific gravity be as
high as 1-04, it forms a black, as appears in the three suc-
ceeding specimens. \i x x {-'jM

3. This piece shows two different
shades of purple, or rather black
and purple along with red, all dyed
at once. The black and purple are
printed together by the cylinder ma-
chine, with two copper rollers, and
the purple is printed afterwards by
the block.

16

Dr. Thomas Thomson

4. Cochineal Pink. — After the
black in this pattern has been pro-
duced in the way already detailed,
it receives an alum mordant on those
parts which are intended to become
pink. It is then cleansed and dyed
in cochineal, in a similar way as

when cloth is dyed with madder. The cochineal does not
tinge the ground as madder does ; and therefore, does not
require, nor is it of sufficient permanence to bear the same
clearing operations. So much colouring matter does the
cochineal insect contain, that one ounce is sufficient to dye
fifteen or twenty yards of such a pattern, as No. 4.

5. Logwood Black. — The same alumi
mordant which forms a red with
madder, becomes black when dyed
with logwood. The iron mordant
has the same property ; but it forms
a brownish, and less pleasing colour.
Rinsing the piece of goods in hot
bran and water, is sufficient to remove the tinge of los:w<
from the white ground.

6. The two shades of colour in
No. 6, are obtained from mixed alum
and iron mordants, dyed in a mix-
ture of madder and quercitron bark.
The mode of producing the black
and white figures on it, will be ex-
plained afterwards.

7. Prussian Blue — The iron mor-
dant is applied, and the cloth cleansed
in the way already described. It is
converted into prussian blue of va-
rious hues, by immersion in cold
prussic acid. This acid is liberated
from a weak solution of prussiate of
potash, by an equivalent of sulphuric acid. A more
convenient process for this colour, is now employed,
and it will be explained, when we come to speak of steam
colours.

1835.]

Gdico- Printing .

17

8. Buff from Iron. — This pleasing
colour is merely the peroxide of iron.
A mixture of sulphate of iron and
acetate of lead is printed on the cloth,
constituting in fact, sulphate and
acetate of iron together. After ex-
posure to the air for a considerable
time, to produce as large a deposit as possible upon the
cloth, the iron is farther precipitated by immersing the
piece in thick lime water, or in a mixture of caustic potash
and lime. A portion of black oxide is thus thrown down
along with the red, which speedily changes in the fresh
water and air to which it is afterwards exposed.

9. Manganese Bronze. — A solution
of sulphate of manganese is printed on
the cloth by the copper roller. When
dry, the piece is passed through a
strong caustic alkali, and then allow-
ed to fall into a vessel containing chlo-
ride of lime. This converts the man-
ganese into sesquioxide, which has a strong affinity for cotton .

10. China Blue.
fixed upon cotton in a

Indigo may be
variety of

ways. By heating it with orpiment
and caustic potash, it is deoxidized
and dissolved. If gum-senegal or
roasted starch be not dissolved in the
solution, it forms what is called
pencil blue, which may be printed upon cloth by means of
the copper roller, or by the block from a sieve of a peculiar
kind. Applied in either of these ways, the indigo soon re-
covers its blue colour, and being no longer soluble, it
remains upon the cloth, while water removes the substances
with which it was mixed.

By another process, indigo in the blue state is mixed
with orpiment in a solution of sulphate of iron, and de-
oxidized after being printed on the cloth, by alternate im-
mersions in lime and copperas. It is known that indigo
in the deoxidized or white state, is soluble in alkalies,
forming a yellow coloured solution. This solution deposits
its deoxidized indigo on the cloth by mere contact. In this

vol. i. c

18 Dr. TJiomas Thomson on [Jan.

way the indigo which is at first loosely laid upon the fibres,
and easily removeable by washing, is slowly combined with
them, and thus becomes fixed on the cloth. A large quan-
tity of iron is necessarily attached to the cloth during this
process, and a continued action of sulphuric acid is neces-
sary for its removal.

A third process consists in dissolving powdered indigo in
a hot solution of potash, and stannite of potash, or by boil-
ing it in potash or soda, along with metallic tin. It is
then precipitated in a white state by muriatic acid, and
the precipitate being thickened and mixed with fresh
chloride of tin, is printed on the cloth. When dry, the
piece is immersed in a solution of carbonate of soda. The
indigo becomes yellow by combining with the soda, and in
this soluble condition, attaches itself permanently to the
cloth. It soon afterwards becomes blue, by the absorption
of oxygen from the atmosphere.

11. Catechu Brown. — This im-
portant dye-stuff, formerly known
by the name of terra japonica, is
procured by boiling the brown heart
wood of the acacia catechu, or
khair-tree. It is obtained by sim-
ply boiling the chips in water, until ^ 1 BF mj£^jj2^&'£
the inspissated juice has acquired a proper consistency.
The liquor is then strained, and soon coagulates into a mass.
It comes to this country both from Bombay and Bengal.
It consists chiefly of tannin, but contains also a little alu-
mina, which may perhaps assist in fixing the colour on
the cloth.

The catechu is dissolved in acetic acid; a solution of
copper and sal ammoniac is added to it, and the whole
printed on the cloth. It is allowed to stand a few days, during
which the colour deepens very much, and is then worked off.

Chrome Orange. --The dichromate jt w *3flt* *4aS*
of load is precipitated upon the sur- •nT" *it
face of cotton cloth, by printing on '-
it a solution of lead, and then im-
mersing the cloth in a hot solution
of a chromic salt of potash, or of {
lime, containing a slight excess of

1835.] Calico- Printing. 19

base ; or, it is sometimes obtained from the yellow chro-
mate of lead, produced from the bichromate of potash, by
abstracting a portion of its acid in hot lime-water.

To be continued.

Article II.

A Journey in Spain. By M. F. Le Play. (Abridged
from the Annals des Mines, torn, v.)

Spain presents numerous points of interest to the man of
science, but in proportion as this fact has been gradually
developing, so has the political state of events in that un-
fortunate land increased the difficulties of investigation. It
appears, however, unquestionable, that the obstacles to
travelling, at least on the thoroughfares of Spain, (as from
Bayonne to Cadiz, where the route is as fine as any on the
continent) have been greatly exaggerated.

Spain was anciently celebrated for its mineral riches.
Pliny speaks of lead, tin, iron, copper, silver, gold, and
mercurial mines, which were all in activity, but were relin-
quished towards the termination of the Empire of Rome.
The Moors explored numerous mines, in the east of the
Peninsula, but on their expulsion these sources of wealth
were entirely abandoned. Spain still bears on its surface
permanent marks of the energy with which the improve-
ments introduced from the east were overturned. When
the traveller demands the cause of the innumerable ruins
and abandoned mines which cannot fail to attract his atten-
tion, he learns that these desolating catastrophies occurred
at the expulsion of the Moors. As a finishing blow to
Spanish industry, the Kings of Spain in the fifteenth cen-
tury,issued an interdict against working the Peninsular
mines for the purpose of encouraging those of America.
The mercurial mines of Almada alone were in operation ;
because, their product was necessary for the extraction of
the precious metals in New Spain. The quantity sent from
thence annually, amounted to 6000 quintals. Towards the
middle of last century the mine of Huancavelika in Peru,
which had previously supplied the greatest part of the

c2

20 A Journey in Spain [Jan.

mercury for the precious mines, became depreciated in the
quality of its product, and thus a new stimulus was afforded
to those of Almeyda. But these intervals of prosperity
seem to have been the mere flickerings of the flame before
it expired, for war raged in the Peninsula, America as-
sumed its independence, and the industry of Spain was
almost extinguished. In this condition Spain remained till
1820, when political events changed in some measure the
state of affairs.

The inhabitants of the mountainous country of Alpujarras,
who had lived, from the time of the departure of the Moors,
in a wretched and immoral state, roused themselves from
their lethargy, on the intelligence of the destruction of the
odious monopoly, and began to work their lead mines. In
the course of a few months these poor men were compari-
tively wealthy, for by 1826, no less than 3500 mines
were in activity in the Sierras of Gador and Lujar ; and in
1833, M. Play ascertained that 4000 shafts had been opened
in the Sierra of Gador alone. Before 1820, the royal works
which had the sole power of smelting ores, produced annu-
ally only thirty or forty thousand quintals of lead. In
1823, however, the product was increased to 500,000, and in
1827, to 800,000 quintals.

This prodigious increase in industry created a great sen-
sation in Spain ; and all classes of society, directing their
attention to the mines', conceived that they had only to turn
up the soil, in order to acquire endless treasures.

The government, at the same time, gave its countenance
to the labours of the people, by forming two mining schools,
the one at Madrid, the other at Almeyda, and by sending
several young men to study the art of mining at Freiburg.
M. Vallejo, who had been banished during the political
disturbances, and had improved his time by studying at
Paris, returned to his native country, and is at present
engaged with a geological description of Spain. Erlorza
also, an artillery officer, having visited the iron works of
England, Belgium, Hartz, Piemont, and France, has in-
troduced the most approved smelting system of these
countries, into the neighbourhood of Marbella and Pe-
droso in Andalusia. By his advice the iron works of Gal-
licia have been altered ; and speedily his improvements

1835.] by M. F. Le Play. 21

will extend over Spain. During the short period described,
the product of the mercurial mines of Almeyda increased ;
the ancient copper mines of Rio Tinto long neglected, were
now worked with energy ; the calamine mines of Alcaraz,
in the eastern part of La Mancha, are successfully explored
at present, lead is raised in considerable quantities at
Linares in Jaen, and at Falsete in Catalonia. In the
neighbourhood of Oviedo, rich mines of coal which occur
there, supply, although the communication is bad, the
establishments of Andalusia. Coal mines have also been
opened by a company near the river Aviles ; and in another
part of Spain, the small coal bason of Villa Mieva del Rio,
situated eight leagues above Seville, is worked with increas-
ing activity, and supplies the steam boats, which make the
voyage from Seville to Cadiz in twelve hours.

'M. Le Play travelled by Tolosa, Miranda, through the
Sommo Sierra to Madrid, by Cabrera and Alcovendas, and
made the subsequent observations.

At Vittoria the powerful causes which have given to the
Pyrenees their form, is strongly observed ; and near this place
also occurs the border of the sea, in which are deposited ter-
tiary formations. This border, as well as the two stages of
the cretaceous formation, is parallel to the direction of the
two principal edges of the Pyrenees, running nearly from
west 18° N., to E. 18° S. Hence, Biscay, Navarre, and the
North of Arragon, present a simple geological structure ;
and the road from Bayonne, nearly perpendicular to the
direction of the chain, is extremely favourable for studying
the two bands of chalk, below which the Jura formation
shews itself occasionally. The plains of Old and New
Castile appear to have been recently elevated, and sub-
sequent to the deposition of the most modern tertiary for-
mations, for Le Play has observed that the surface was
formed exclusively of tertiary masses of calcareous marls,
gypsum and compact limestone ; and below these stratified
rocks, thick beds of sand and rounded pebbles occur, which
possess a considerable depth in the plains which cross the road
from Madrid to Estramadura, between the Tagus and the
boundaries of Old and New Castile. Le Play considers this
formation as contemporaneous with the formation produced
by the disruption of the principal Alpine chain.

22 A Journey in Spain [Jan.

The tertiary layers are observed thick at Briviesca in Old
Castile, and in the undulating plain to the south of Madrid,
and at Cuesta de la Reyna, on the sides of the great cut
which exists in this plain near Aranjuez, where the Tagus
and Jarama unite. The sea in which these tertiary forma-
tions are deposited appears to have extended in the direction
from Bayonne to Cadiz over Aragon, and to have commu-
nicated with the Mediterranean by an opening across the
mountains of Valencia and Catalonia, which was probably
the ancient strait of Gibraltar. The southern part of Spain
seems to have been only recently disjoined from Africa.
The epoch of the elevation of Central Spain is referred by
Le Play to that of the principal chain of the Alps ; the na-
ture of the soil, the directions of the chains of mountains,
the course of the rivers, the stratification of the rocks,
being sufficient traces of a revolution contemporaneous
with the appearance of the ophites.

The Sommo Sierra chain, whose summits are clad with
snow during the whole year, is almost entirely composed of
granite, which has broken a thick layer of gneiss and mica
slate, at some remote period.

No trees adorn the desolate plain which extends from
Sommo Sierra to Madrid; and no symptom of an approach-
ing capital is observed until the traveller fairly reaches
Madrid, which forms a perfect oasis. Over the small stream
Manzanares, an elegant bridge conducts to the capital of
Spain. Here the only object of interest is a cabinet of
natural history, derived from Spain and its colonies, but
arranged according to the systems extant in the reign of
Charles III.

Within a few years Government have instituted a school
of mines, which although well supported in some of its
departments, with the exception of a considerable library,
collections of minerals and apparatus, is defective in the
necessary means for instructing students.

The great plains which extend from the Tagus to the
mountains of Guadarrama, consist of clay and sand. The
greatest part is uncultivated; but the abundant natural
harvest of lavender and leguminous plants, is a sufficient
proof of the fertility of the soil. At Talavera, however, the
soil is richly cultivated, and the numerous aqueducts which

1835.] by M. F.LePlay. 23

rise above the olive groves, are a lasting memorial of the
exertions of the Arabians in the advancement of agriculture.
Travelling in Estramadura is dangerous, for even the
husbandman is compelled to arm himself during his la-
bours in the field. From Almaraz to Trujillo, the traveller
passes through forests of oak, and gradually descends to
the latter city, the birth-place of Pizarro, which is situated
on the sides of a granite hill. The granite of Trujillo is
separated from that of Sierra de Guadelupe, by a band of
transition slate. Near Logrosau, small veins of quartz and
phosphate of lime occur, which have been magnified into
mountains of phosphate of lime, by some credulous indi-
viduals.

To Almeyda from thence, the soil consists of solid peb-
bles, and on the South-East, at the Guadiana, a transition
plain exists. Almeyda in some points resembles the Hartz,
but especially in the manners of the people, which have gradu-
ally at different periods been introduced from Germany. The
mines of Almeyda are very ancient ; for according to Pliny,
the Greeks extracted vermillion from them 700 years before
our era. The Romans drew annually from them, 100,000
livres of cinnabar.

The present flourishing state of these mines is indicated
by the fact, that 22,000 quintals of mercury are annually
furnished by them, and that 700 men are employed in mining,
200 in extracting the ore, besides a great number of mule-
teers, who convey the mercury to Seville. The veins are
so rich, that although the mines have been worked for ages,
the mining has only been carried the depth of 300 varas, or
300 metres. The whole vein is extracted, and when distilled
yields 10 per cent, of mercury. The same mineral is found
in a number of points in the direction of a band, which ex-
tends to Almadenejos, where the metal is extracted from a
black slate, containing very little cinnabar. The minerals
are treated at Almeyda in eight furnaces called Buytrones,
and at Almadenejos in five.

The mercury has a fatal action on the industrious miners,
and with infinite regret the traveller beholds men in the
prime and vigour of their days, presenting a deadly aspect.
M. Play passes a high eulogium upon the manners of the
miners, whose characters in every respect are of the high-
est order.

24 A Journey in Spain [Jan.

The Sierra Morena form a chain of round topped moun-
tains, appearing naked and barren when seen from afar,
but in reality covered with a diminutive forest of strawberry
trees, (Arbutus Unedo) pistachio, and different species
of cisti.

Near Cordova, at the foot of the chain, the waterworm
stone formation is observed, where it covers a shell lime-
stone containing fossils identical with those of Corsica.

The whole of the low plain of Andalusia appears to con-
sist of a formation analogous with that of Castile ; but as
the characters of the formation are different in a mineralo-
gical point of view, the sea in which it was deposited,
must have been separated by the promontory of the Sierra
Morena. The central part of Estramadura is covered
with a rich herbage, which affords abundant pasturage to
the Merino sheep.

At Badajoz, a small chain of tertiary hills crosses the
Guadiana ; and dislocated shell-limestone passing to dolo-
mite, is in intimate connection with the infiltrations of
crystalline rocks, of diallage and hypersthene. The latter
are also met with at Almeyda Cazallase. The tertiary
sand extends parallel to the frontiers of Portugal, while
the chain of Alburquerque consists of slate and quartz,
affording a curious succession toward Caceres, from gra-
nite to slate, and transition greywacke. The slate and
grey wacke are cohered with beautiful forests of green oaks
and cork trees, but the granite is destitute of vegetation.
The chain of Montanches consists of granite. The Sierra
d'Orellana, a transition ridge contains hematite near Oxel-
lanita. To Llerena, the rocks are slate and greywacke,
but here, limestone occurs with beds of galena, car-
bonates of copper, &c, and extends along the Rio Biar.
Near Fuente del Arco a small bason of coal occurs, with
nearly horizontal beds. The sides of the hills here are
covered with beautiful olive plantations, and the soil
though little cultivated, is of the richest and most pro-
mising nature.

In the beginning of the seventeenth century, the silver
mines of Guadalcanal near Llerena, were worked by two
Germans, brothers, of the name of Fuggars, who amassed
great wealth, and gave origin to the proverb still current in

1835.] by M. F. Le Play. 25

Spain, as rich as Fucares. The mineral is contained in cal-
careous veins, in small quantity, but not in the sulphate of
barytes, which occurs also in the neighbourhood.

Recently a company have re-opened these mines, but it
is feared, will be obliged to relinquish them, after an expen-
diture of above 4000Z. At Cazalla, silver mines were for-
merly worked, but are now abandoned. African vegetation
is here observed in the form of the Agave Americana and
Chamoeras humilis. The Sierra Morena, to the north-east
of Seville, contain a great variety of stratified rocks belong-
ing to the transition formation, but are principally formed
of granite and mica slate. At the foot of these mountains
is the coal bason of Villa Nueva del Rio, which is bounded
on the south by the plain of the Guadalquiver. This coal is
worked by a company of Seville, and the peroxide of iron
is smelted by another company at Pedroso, the product be-
ing exported into France in the form of bars.

Seville is one of the most prosperous towns in Spain,
which it owes to its situation on the fine navigable Guadal-
quiver, and to its admirable climate, — for here oranges and
dates grow luxuriantly, and plants of the warmest climates
are matured in the botanic garden. Seville possesses an
excellent cannon foundery, where the best pieces in Europe
are cast.

On the Rio Tinto we meet with copper mines, which
were worked by the Romans, Arabians, and Moors, and
were re-opened in the beginning of the eighteenth cen-
tury, but it was only in 1787, that the present method of
extracting the copper by cementation with iron from the
water flowing from the mine was adopted. The iron em-
ployed for this purpose is derived from Pedroso, and the
quantity of copper raised amounts to 1800 quintals. The
country by the mouth of the Guadalquiver to Cadiz and
Tarifa, consists of tertiary formations ; and at Conil, clay
marl occurs, impregnated with abundance of sulphur
crystals.

The coast, from Tarifa to Almeria, is extremely uniform
in its configuration, presenting a ridge of lofty mountains,
rising up from the sea, formed of clayslate and limestone,
with occasional masses of serpentine, dolomite, calcareous
and dolomitic brecchia.

26 A Journey in Spain [Jan.

Protoxide of iron is found half a league from Marbella,
at a considerable height on the south of Sierra de Ronda,
and is smelted in the works of Rio Verde, either by the
charcoal furnace or by the reverberatory furnace, with coal
which is brought by the French ships from Asturia.

The hills in the vicinity of Grenada, consist to a consi-
derable height of sand, and at Vega appear to cover the
marls and gypsum of the lacustrine bason of Alhama. On
the heights of Alhambra and Generaliffe, the debris of
grenatiferous mica slate, as upon the summits of the Sierra,
are observed in abundance. The Sierra Navada owes its
origin to several successive disturbances, but the presence
of sand at such an elevation above the plain of Grenada,
leaves no doubt of the very recent occurrence of the last of
these movements. If the sands of Generaliffe be contem-
poraneous with those of Castile, and be superior to the
marl and gypsum, then it is probable that their elevation
was accomplished simultaneously with the origin of the
Eastern Alps. The direction of the summits of the Sierra
Nevada, is from E. 20° N. to W. 20° S. No granite could be
detected on their summits; but mica slate was noticed.
It is probable that an attentive examination of this ridge
may throw some light upon the theory of Beaumont. The
country between the Sierra Navada and the sea consists of
elevated chains, whose summits are covered with mica
slate, filled with garnets; but the central part of these
mountains is principally composed of clay slate, associated
frequently with brecchia, united to black saccharoid lime-
stone, dolomite, fragments of limestone, quartz, and talc-
slate, which are found at a great elevation.

It is in the ridges of Alpuj arras nearest the sea, in the
Sierra de Lujar and Gador, that the lead mines occur
which have been already mentioned. The Sierra de Gador
is chiefly composed of the same compact limestone which
associated with the clay-slate, and intersected frequently
by masses of gypsum, serpentine, &c, form a great portion
of the chain which extends from Almeria to the Straits of
Gibraltar. The product of the mines is so far from de-
creasing, that in consequence of the depreciation of the
price of lead, and the abundance of the ore, it was deter-
mined to cease from working during six months of the

1835.] by M. F. Le Play. 27

year, which raised the price of the metal. The Galena,
from the Sierra de Gador, is used in the state in which it
comes from the mines, in thirty-one different works, com-
prising sixty-nine reverberatory furnaces, and fifty-eight
common furnaces ; the minerals affording, by the former
method, sixty-six per cent. The mountainous nature of
the country renders the formation of good roads imprac-
ticable, and hence, the product of the mines is carried, by
numerous troops of asses and mules, first to the works,
and then, after reduction, to the ports of Adra, Roquetas,
and Almeria.

Article III.

On Respiration. By Thomas Thomson, M. D., F. R. S.,
L . and E . , &c . Regius Professor of Chemistry in-the Uni-
versity of Glasgow.

When the experiments on respiration were made by
Lavoisier, Goodwin, Menzies, Davy, &c, towards the end
of the last century, it seems to have been the generally
received opinion, that every individual by inspiring the
air into his lungs, produces the very same change upon it.
At least, the conclusions respecting respiration to be met
with in Physiological and Chemical books, depend for their
accuracy, upon this assumption. Nothing, however, can
be farther from the truth. The chemical changes produced
in air by respiration, vary in their extent, not only in
different individuals, but even in the same individual at
different times ; and that to such an extent, that if we
analyze air thrown out of the lungs at different times, we
find the quantity of carbonic acid, sometimes not to exceed
two per cent, and at other times to amount to more than
seven per cent. Dr. A. Fyfe and Dr. Prout have shown
many years ago, that an alteration is produced in the
quantity of carbonic acid in the air expired, by the mode
of living of the individual : that when the constitution is
affected by mercury, the proportion of that gas in the air
expired is diminished, and that it is diminished also by
nitric acid, by spirits, and by a vegetable diet. But I have

28 Dr. Thomas Thomson [Jan.

found that the most unexpected alterations are observable
in the same individual, though he be in perfect health,
and though he make no sensible alteration in his mode of
living.

During the course of the month of May, 1832, 1 analyzed
air from my own lungs on ten consecutive days, between
eleven and twelve o'clock each day. Before stating the
results, it may be proper to mention the method of analysis
employed. I procured a glass tube, capable of holding
about three cubic inches of air, and about half an inch
in diameter. It was shut at one end and open at the
other. This tube being filled with mercury, and placed
inverted on a mercurial trough, I introduced into it about
two and a-half cubic inches of air from my lungs, taking
care, in the first place, by making half an expiration
through a narrow glass tube, to expel all the common air
from the trachea and mouth, and also from the tube, by
which it* was conveyed to the eudiometer. The surface of
the mercury in the tube was then marked by tying round
it a sewing thread, and the whole was left till the air
ceased to contract. Then a quantity of moderately strong
potash ley was introduced, and the whole was left un-
touched for twenty-four hours. The diminution of bulk of
the air was then carefully marked, by tying a sewing
thread round the tube at the new surface of the mercury.
I then filled the tube with mercury, up to each of the places
marked by the sewing threads, and weighed each portion
of mercury. The difference between the two weights, gave
the diminution of bulk sustained by the air, by the absorp-
tion of its carbonic acid. I then calculated, what the bulk
of the air and of the carbonic acid gas absorbed would have
been, at the mean pressure and temperature; making
allowance for any change in the height of the barometer
and thermometer, which took place during the interval.
I ought to observe, however, that during the ten days of
these experiments, both the barometer and the thermometer
were tolerably steady.

The following table exhibits the volume of carbonic acid
gas, in 100 parts of the air expired from my lungs during
each of the ten days, at 11 o'clock a. m. : —

1835.]

on Respiration.

29

CARBONIC ACID.

4-64

per cent.

4-70

tt

6-07

(<

3-27

it

526

a

CARBONIC ACID.

6 - 2-05 per cent.

7 - 2-39

8 - 3-85

9 - 3-05
10 - 7.16

I was not a little surprised at these results : the diffe-
rences being so much greater than I had anticipated. The
mean of the whole is 4*24 per cent., which, therefore, I am
disposed to consider as representing the mean quantity of
carbonic acid gas, contained in 100 volumes of air expired
from my lungs.

I was naturally induced to examine the air from the lungs
of several other persons, in order to see whether there
would be the same difference in theirs as I had observed
with respect to myself. The gentlemen whose breathing
was examined, were chiefly those who were occupied with
practical chemistry in my laboratory. The following table
exhibits the results obtained : — ,

CARBONIC ACID.

Mr. Thomas Thomson, (aged 14) 3*06 per cent.

Ditto, next day

-

-

3-61

Mr. J. Colquhoun,

(aged 18)

3-09

Mr. Forrest, (aged 18)

-

2-10

Ditto, next day

-

-

5-19

Mr. Coverdale

-

-

2-54

Ditto, next day

-

-

1-71

Mr. Cargill -

-

-

4-68

Mr. Bruce

-

-

5-46

Dr. Duncan

-

-

6-17

Dr. Short

-

.

6-85

Mr. Frazer

-

-

7-08

I prevailed upon two ladies to allow me to examine the
air from their lungs. The first was an unmarried lady
about seventeen years of age ; the second a married lady,
aged about thirty. The results were as follows : —
First lady - 2-35 | Second lady - 4*06
The diversity here is fully as great as in my own case,
but the mean of the whole does not differ much from that
of my own. I am disposed, therefore, to infer from these
trials, that the average volume of carbonic acid gas, in 100

30 Dr. Thomas Thomson [Jan.

volumes of air, expired from the lungs at 11 o'clock a. m.
is 4-24.

But, from Dr. Prout's experiments, (Annals of Philoso-
phy, II., 328; and IV., 331,) it appears that the quantity of
carbonic acid gas produced by respiration, is at its maxi-
mum at noon, and that its quantity at 11 a. m. is to the
mean quantity for 24 hours, as 3*92 to 3*45. It is obvious,
from this, that the mean volume of carbonic acid gas in
100 volumes of air expired, deduced from the preceding
experiments, is 3*72.

I made a few trials to ascertain how much air different
individuals are capable of forcing out of their lungs after a
full inspiration. The quantity as might be expected, varies
much in different individuals. But when the same indi-
vidual repeated the trial, the result was very constantly the
same. The following table shows the results : —

Mr. T. Thomson 150 cubic inches.

Mr, G. Thomson 163

Dr. Duncan - 180

Dr. Thomson 193

Mr.J.Colquhoun200

Mr. Coverdale 200

</

Mr. Bruce

• 200

Mr. Forrest

- 200

Mr. Frazer

- 200

Dr. Short

- 210

Mr. Cargill

- 250

200 cubic inches is the most common quantity ; but in one
case it amounted to as much as 250.

The number of respirations in a minute does not vary
much in different individuals, being very nearly twenty, or
rather between nineteen and twenty.

I believe that great errors have been committed in the
attempts to determine the quantity of air thrown out of the
lungs by a common expiration. I am satisfied that the
quantity which I pitched upon from the experiments of
Menzies, Lavoisier, &c, namely, forty cubic inches is far
too high. I find, after a great many trials, (for it is very
difficult to make a natural expiration when your attention
is called to it,) that the quantity of air which I myself throw

1835.] < on Respiration. 31

out at a natural expiration, is sixteen cubic inches. My
nephew, Dr. Andrew Steel, who was a tall man, (about six
feet,) with an expanded chest, also made many trials, and
satisfied himself that his ordinary expiration was sixteen
cubic inches. Messrs. Allen and Pepys determined the
volume of air expired by them at an ordinary expiration, to
be sixteen and a half cubic inches. From these facts, I
think we are entitled to conclude that a common expiration
does not much exceed sixteen cubic inches.

If these data be correct, and they cannot be very far from
the truth, it will be very easy to calculate the quantity of
carbon thrown out of the body daily by respiration. Allow-
ing 20 respirations per minute, and 16 cubic inches of air
taken in and thrown out at each respiration, we have
28,800 respirations in 24 hours, and 460,800 cubic inches
of air passing through the lungs. Of this |I2 or 17141*76
cubic inches are converted into carbonic acid gas. Now 100
cubic inches of carbonic acid weigh very nearly 50 grains : so
that the weight of carbonic acid formed is 8,570*8 grains,
fxths of which, or 2337*5 grains are carbon. This amounts
to nearly nine ounces avoirdupois, or somewhat more than
half a pound.

Article IV.

On the Changes produced in the Composition of the Blood by
repeated Bleedings. By Thomas Andrews, Esq.

The object of the following experiments is to determine
with precision, the changes which are produced in the com-
position of the blood by repeated abstractions of large quan-
tities of it from the general circulation. In the human
subject, opportunities seldom occur of procuring proper
specimens for examination, although the operation of vene-
section is so frequently performed, as in those cases where
it requires to be repeated at short intervals the blood is
generally in a morbid state. Instead of waiting for such
casual occasions, I directed my attention to those animals
in which the composition of the blood is nearly the same as
in man, conceiving that similar results would in either case
be produced. I selected the blood of calves for the purpose
of experiment, and as it is the practice of butchers in this

32

Mr. Andrews on the Changes of the

[Jan.

country to bleed these animals several times before they are
slaughtered, I availed myself of this circumstance to pro-
cure suitable portions of blood . The animal is bled from a
large orifice in the jugular vein, till symptoms of syncope
appear, and the operation is in general repeated at intervals
of twenty- four hours. It is once fed between each operation
upon a mixture of meal and water, but this is often omitted
before the last bleeding.

The appearance of the blood becomes greatly altered by
the successive abstractions; the crassamentum is at first
very large, and a portion of the red globules are unattached
to it, but it progressively diminishes in bulk while its con-
sistency increases, till upon the fourth bleeding it appears a
small contracted ball immersed in a large quantity of serum,
adhering to the stopper of the vessel in which it is contained,
and presenting on its external surface an exact cast of the
interior of the vessel.

The following analyses were performed by the same me-
thod that I formerly employed in a set of experiments on
the blood of Cholera patients, which were published in the
Philosophical Magazine for September 1832. They are
nearly all a mean of two separate analyses which seldom
differed from each other more than 0*5 per cent.

A calf was bled four times ; between the first and second
bleedings a week elapsed, but the rest took place at intervals
of twenty-four hours, and the animal was fed between each
operation. The composition of the serum and blood at each
bleeding is exhibited in the following tables :

SERUM,

Water ....
Albumen and Salts

Water

Albumen and Salts.
Red globules & fibrin

FIRST.

SECOND .

THIRD.

FOURTH.

92.19

7-82

93-96
6-04

93-81
6-19

94-18

5-82

100-00

100-00

100-00

100-00 j

BLOO]

D.

'

FIRST.

SECOND.

THIRD.

FOURTH.

81-36

6-89

11-75

85-49
5-50
9-01

87-41

5-77
6-82

89-25
5-52
5-23

100-00

100-00

100-00

100-00

1835.]

Blood by repeated Bleedings.

33

The serum had at the third bleeding, a specific gravity of
1-020, and at the fourth, of 1*017. At the third bleeding,
the specific gravity of the blood itself was 1*031.

The next calf whose blood was examined, was nine weeks
old. I did not procure any blood from the first bleeding.
The third bleeding was twenty- four hours after the second,
and during that period, the animal was once fed ; twelve
hours afterwards it was bled a fourth time, but it received
no more food :

SERUM.

,

SECOND.

THIRD.

FOURTH.

Water

Albumen and Salts

93-32
6-68

94*39
5*61

94-59
5-41

100-00

100*00

100-00

BLOO

D.

SECOND.

THIRD.

FOURTH.

Water

Albumen and Salts

Red Globules and Fibrin

82-05

5-85

12-10

89-14
5-29
5-57

88-92
5-06
6-04

100*00

100-00

100-00

The albumen and salts it is evident, decrease at each
bleeding ; the diminution is, however, very variable, and
even after the fourth time, does not amount to one per
cent, and a half. In the globules, the same diminution takes
place, but to such a degree that they are at least reduced
to less than one half their original quantity. To this prin-
ciple, a remarkable exception occurs in the composition of
the blood taken at the last bleeding of the second calf,
where the globules are slightly increased above the pre-
ceding analysis ; but it will be observed, that the animal
received no food during the intervening period, from which
the blood might obtain a fresh supply of serum, while the
tendency of the different excretions of the animal was to
drain from the circulating mass its aqueous part, and thus
to increase the apparent quantity of the globules. This
explanation is confirmed by the following analysis.

A calf three weeks old was bled twice before it was

VOL. I. d

34

Dr. R. D. Thomson on the History

[Jan.

killed, twelve hours elapsed between the two bleedings,
during which time it obtained no food : —

SERUM.

FIItST.

SECOND.

Water

Albumen and Salts

92-48
7-52

93-35
6-65

100-00

100-00

BLOOD.

FIRST.

SECOND.

Water

Albumen and Salts

Globules

82-48

6-70

10-82

83-47

5-95

10-58

100-00

100-00

The globules have here it is true diminished at the second
bleeding, but so slightly, that we may attribute this cir-
cumstance to the unassimilated chyle which must have been
present in the system. In the former case, the animal
had been exhausted by previous depletions, and hence pos-
sessed no store from which the blood could derive even a
small portion of serum, as in the latter instance.

Article V.

History and Analysis of the Vanadiate of Lead. By

Robert D. Thomson, M. D.

" »v

When the history of the brown lead mineral of Zimapan is
considered, it appears not a little remarkable that Vana-
dium should have remained for nearly thirty years in obscu-
rity, after the idea of its existence was suggested. But the
discovery of the metal within the last few years, is a strik-
ing proof of the improvement in chemical analysis, and of
the assiduity and careful scrutiny with which the whole
material world is in progress of being examined.

Humboldt, under the date of 14th November 1803, pub-
lished in Gehlen's Journal, a notice of the analysis of a

1835.] and Analysis of the Vanadiate of Lead. 35

brown mineral from Zimapan, by Del Rio, in which the
Mexican chemist it was stated, had discovered a new metal.
The mineral was considered similar to specimens from
Schoppau in Saxony, Hoff in Hungary, and Pollaven in
Brittany.*

Andre del Rio appears to have examined the Zimapan
mineral in 1802, and to have written a memoir in which he
expressed his opinion that this substance was not a phosphate,
and that it contained neither uranium nor chromium ; and
stated that he procured from it 14-8 per cent, of a new
metal, which at first he called Panchrome, on account of
the variety of colours presented by its oxides and precipi-
tates, and afterwards Eritrone, because it formed with alka-
lies and earths, salts which became red either by heat or by
acids. t But having read in the work of Fourcroy that
the chromates afford by evaporation yellow or red salts, he
came to the conclusion in 1804, that the brown mineral
was a chromate of lead, with an excess of base, in the state
of protoxide of lead. %

In his Spanish translation of the Third Edition of Kars-
ten's Mineralogical Tables, published in Mexico in 1804, he
used language still more strongly opposed to his original
opinion, and affirmed that the mineral consists of

Oxide of lead . . . . i 80-72
Chromic acid . . . ' . .14*80

Arsenic, oxide of iron, and muriatic acid 4*48

100-00

He found the quantity of arsenic to amount sometimes to
two per cent., and always observed its presence, both by
distillation and the blow-pipe.

It is quite obvious, from these two separate recantations,
that Del Rio was convinced, from his own researches, that
the substance which he at first considered new, was one
which was already known to chemists, and that his original
experiments were not valid. The observation, therefore,

* Gehlen's Neues Allgemein journal der Chemie, 6th part, vol. ii. 695.
t Annates de Ciencias Naturales de Madrid, No. 19, February 1804. Annales
des Mines, iv. 499.

% Annales de Ciencias, No. 19.
§ Gilbert's Annalen der Physik, Ixxi. 7.

D 2

36 Dr. R. D. Thomson on the History [Jan.

of Berzelius, that Del Rio was induced to alter his opinions
in reference to the composition of the Zimapan mineral,
out of respect to scientific authority is incorrect.*

The Annates de Ciencias Naturales of Madrid, the medium
through which Del Rio communicated the change of his
views, although published by the Spanish botanist Cava-
nilles did not find their way among chemists in general.

In the Journal de Mexico of the 11th September 1811,
Del Rio published a true statement of the case, an extract
of which was given in the Annates des Mines, (IV. Vol. for
1819,) transmitted by Alaman a Mexican mineralogist.

Collet Des Cotils, who had heard of the discovery of Del
Rio, but unaware of the repetition of his experiments,
having been furnished with a specimen of the mineral,
analyzed it and published his results in 1805, a year after the
corrected analysis of the Mexican chemist had appeared. f

Des Costils found the mineral to afford before the
blow-pipe upon charcoal, sometimes a slight smell of arsenic,
and to be speedily reduced.

Heated with borax, it dissolved readily, and gave it a
light emerald-green colour. His method of analysis was as
follows : A portion of the mineral in powder, having been
digested with the assistance of a gentle heat, in dilute
nitric acid, the whole of it dissolved, forming a clear yellow
solution with a tinge of green, except a small quantity of a
reddish matter, which he found to be oxide of iron, contain-
ing a little silica and chromic acid. Into the solution, con-
centrated sulphuric acid being then poured, a white powder
fell, which was recognised as sulphate of lead. The filtered
liquor afforded no precipitate with ammonia. The excess
of ammonia was dissipated, and the acid thrown down by
nitrate of lead. The precipitate was yellow, resembling
the chromate of lead, and contained some sulphate of lead,
which was removed by taking up the chromate, by digestion
in nitric acid. In another experiment, the mineral was
dissolved in muriatic acid ; the excess of acid removed, and
the mineral acid thrown down by nitrate of silver. A fine
red precipitate was the consequence. With nitrate of mer-
cury, a yellowish compound was formed.

* Kongl. Ventenskap. Acad Handlingar, 1831 — 1
t Anaales de Chimie, liii. 268.

1835.] and Analysis of the Vanadiate of Lead. 37

To determine the quantity, of muriatic acid, a new portion
was dissolved, and the solution was precipitated by nitrate
of silver. The products of the analysis were : —

Metallic lead .....

69-0

Oxygen, (supposed) ....

5-2

Oxide of iron, insoluble in nitric acid .

3-5

Muriatic acid .....

1-5

Chromic acid . . . . .

16-0

95-2

Loss

4.8

100-00

Without dwelling upon the method of analysis adopted
by the French chemist, which was liable to great inaccuracy,
it may be sufficient to recapitulate the grounds upon which
he concluded that the acid contained in the mineral was
identical with chromic acid.

1. The compound of the acid with lead was yellow. It
is now known that the chromate and vanadiate of lead are
both similar in their colour, but identity of colour is not
identity of composition.

2. Nitrate of silver produced a red precipitate. Chro-
mate of silver varies in colour according to the temperature
at which it is precipitated ; being reddish brown when
thrown down from a hot solution, red with a tinge of
purple in its cold state, and carmine red with excess
of acid.

The vanadiate of silver is likewise variable in colour ;
being yellow when neutral, but with excess of acid, deep
orange yellow.

3. Nitrate of mercury produced a yellow precipitate.
Now chromate of mercury is purple or deep red, and
vanadiate of mercury is a fine lemon yellow. From this
fact it is evident, that the conclusions at which Des Costils
arrived were not authorized by the results of analysis, even
in reference to the slender claims which variety in the
colour of the precipitates of analogous acids has by itself
to determine difference of chemical nature.

After the consideration of this analysis, it appears cer-
tainly extraordinary that the nature of the compound should

38 Br. R. D. Thomson on the History [Jan.

so long have been considered as ascertained. So little at-
tention, however, it appears had been paid to the subject
by mineralogists, that Lucas in his Tableau Methodique
des especes Minerales, published in 1813, places the Zimapan
mineral under phosphate of lead, and even in 1817, Brei-
thaupt committed the same mistake.* After the analysis
of Des Costils this interesting mineral remained in com-
parative oblivion till April 1830, when Professor Sefstrbm,
while examining iron from the Mine of Taberg in Smaland,
introduced a new substance to the acquaintance of chemists,
by the discovery of Vanadium, f

In the begining of 1831, Wohler appears to have sub-
jected the brown lead mineral from Zimapan to analysis,
and to have concluded that it was a compound of vanadic
acid, and protoxide of lead. J

In the course of the winter 1830-31, Mr. Johnston states
that his attention was directed to a mineral from Wanlock-
head, which he obtained from a mineral dealer as an arse-
niate of lead, and that he procured by analysis, what at
first he considered impure oxide of chromium ; but having
repeatedly attempted to separate the chromium in an insu-
lated state, and several properties appearing which were
distinct from those of chromium, he concluded that it was
a new substance. §

Having finished the history of the discovery of the vana-
diate of lead so far as I am acquainted with it, I proceed
now to the consideration of the properties and composition
of such specimens as have been subjected to examination.

1. The only quantitative analysis of the native vanadiate
of lead which has hitherto been published, is that of Berze-
lius. The specimen examined was from Zimapan, and pos-
sessed little colour, but it was mixed with oxide of iron,
which gave it a brown appearance. || Nothing is said of its
density, but Breithaupt under the title of Vanadiner blei
spath, states the specific gravity of the Zimapan mineral at
6*831 .H The process of the Swedish chemist was to dissolve

* Del Rio's Letter to Gilbert, 1. Annalen der Physik und de> physikalischen
chemie, lxxi. 7.

t Ann. de chim. lvi. 105.
$ Ann. de chim. xlvi. 111.
§ Edinburgh Journal of Science, v. 166.

|| Kongl. Vetenskap. Acad. Handl. 1831. Annal de Chim. xlvii. 402.
% Vollstandig characteristik des Mineral Systems, 54 — 1832, 8vo.

1835.] and Analysis of the Vanadiate of Lead. 39

the pulverised mineral in dilute nitric acid ; to precipitate
the chlorine by nitrate of silver ; to throw down the excess
of silver by muriatic acid ; to replace the volatilized nitric
and muriatic acids by sulphuric acid ; evaporate to dryness,
and fuse the residue with sulphate of potash, in order to
separate the lead, and to estimate the quantity of acid by
the loss. The results of the analysis were,

Chloride oflead^Iorine «J \ 993

Oxide of lead .... 67-99
Vanadic acid . . . .21*34
Impurity . . . . . *73

100-00
With some corrections, the analyst considers this equiva-
lent to,

Chloride of lead . . . 25-33

Vanadiate of lead . . .74-00
Impurity . . . . .0*67

100-00
No phosphoric acid was detected in it, and a mere trace of
arsenic acid was present.

2. Vanadiate of lead from Wanlockhead according to
Mr. Johnston, is found in two states. 1. In the form of
mamillee, from the most minute size to that of a pin-head,
sprinkled over a surface of calamine. The specific gravity
6*99 to 7*23. Opaque; varying in colour from straw-yellow
to a reddish-brown ; lustre resinous ; streak white. In the
finer specimens, the mineral appears in groups of six sided
prisms. 2. In the second state in which it occurs, it re-
sembles peroxide of manganese when earthy and porous,
presenting an amorphous and rounded appearance ; colour,
steel-grey, fusing before the blow-pipe like the first variety,
and retaining its yellow colour on cooling. The mineral
was found in an abandoned lead mine, but only in one spot,
about six fathoms in length, where the vein presented the
appearance of having been disturbed by violent causes.

3. Hausmann noticed a mineral associated with red lead
ore, which he suspected to be chromate of lead. It pos-
sessed a dark yellowish, or liver brown colour, occurring in
small botryoidal and stalactitic forms, glistening feebly in-

40 Dr. JR. D. Thomson on the History [Jan.

ternally, or glimmering and resinous ; fracture, flat, con-
choidal or uneven; opaque, soft, streak sisken-green. He
conjectured that it was similar to the Zimapan mineral, and
there can be no hesitation in admitting that his suspicions
were correct.*

Native vanadiate of lead has been recently obtained at
Beresow, near Katharinenburg in the Uralian Mountains,
and its mineralogical characters have been investigated by
Gustav Rose.f Among the lead ores in the gold mines, a
green ore of lead is found, which crystallizes in double six
sided prisms. It melts before the blow-pipe, crystallizing
on cooling, and contains some phosphoric but no arsenic
acid. In a specimen brought from Eeresow, Rose observed
the six-sided prisms on one side green, and on the other
brown. Having tried them before the blow-pipe, he found
the brown crystals to be vanadiate of lead. They are re-
gular six-sided prisms, some of them very small, others
larger. The crystals of greater size are found near the lead
ore, and contain a nucleus of the ore. The crystals possess
a chesnut-brown colour, a shining lustre, especially the
small ones, and have the same hardness as the grey lead
ore. Before the blow-pipe the mineral decrepitates strongly,
melts upon charcoal into a globule, and the lead is reduced.

With salt of phosphorus it fuses in the outer flame into
a glass, which when hot is reddish yellow, when cold yel-
lowish green ; and in the inner, into a glass possessing a
chrome green colour.

In nitric acid it dissolves readily. The solution gives with
nitrate of silver, a considerable precipitate of chloride of
silver. The filtered solution gives with sulphuric acid, a
white precipitate of sulphate of lead, and then precipitated
by suphuretted hydrogen, a brownish red precipitate of
sulphuret of vanadium. Rose concludes from these cha-
racters that the mineral he examined was identical with
the brown lead mineral from Zimapan. The vanadiate of
lead of Beresow is found in crevices in granite, .which
communicate with the quartz veins in which gold is found.

The mineral is liable to be confounded with the lead ore,
because both substances crystallize in six-sided prisms, and

* Journal de phys. Ixiii. 38. Jameson's Mineralogy, iii. 413.
t Poggendorff Annalen der Chemie, xxix. 455.

1835.] and Analysis of the Vanadiate of Lead. 41

both are combinations of a salt of lead with chloride of lead.
Rose considers the Beresow mineral to correspond with
that from Zimapan.

4. The mineral which I* am now to describe, was derived
from a different locality from any of those mentioned. It
was brought to Glasgow by Mr. Doran, an Irish mineral
dealer, who stated that he had procured it in an abandoned
lead mine in the county of Wicklow in Ireland, and is now
in Dr. Thomson's cabinet.

Its colour is light brownish yellow, streak white. Com-
monly it appears in the form of small rounded masses or
spheres placed on a surface of phosphate and arseniate of
lead; but sometimes it is crystallized in six-sided prisms.
Opaque with some translucence at the edges, brittle. The
fracture is even or often flat conchoidal. Lustre resinous.
Hardness 2*75. The specific gravity I found by one trial
6*675, by another 6*651, which numbers approach each
other so nearly, that I am disposed to consider the true
density of vanadiate of lead to be 6*663.

When exposed to the action of the blow-pipe on charcoal,
it fuses with considerable frothing into a bead, which is
precisely similar to the mineral itself. If the fusion is con-
tinued the matter spreads on the charcoal, and possesses at
last a dark scoriacious aspect. When the blast is continued
and carbonate of soda added, globules of metallic lead are
produced and a black scoria remains.

With borax fuses into a bead, which is transparent and
red while in fusion, but on cooling it becomes suddenly
opaque and deep blue, when the proportion of vanadiate
is considerable; but emerald green if it be small.

With salt of phosphorus in small quantity, it fuses into
a fine emerald green transparent glass.

30 grains of the mineral carefully broken, and separated
from the substance forming the basis on which the round
masses were placed, were pulverized and digested in a
flask on the sand bath with pure dilute nitric acid. The
whole of the powder speedily dissolved, forming a deep
orange solution, with the exception of a minute portion of
a yellowish coloured matter, which remained in the bottom
of the flask. The contents of the flask were transferred
into a large watch glass.

After remaining at rest for a short period the superna-

42 Dr. R. D. Thomson on the History [Jan.

tant liquor was drawn off, and the residue washed with
repeated additions of pure distilled water. The insoluble
matter when dried on the sand bath, possessed a brown
colour, and weighed 0*07 grain. This lost by a red heat
0*02 grain, leaving for the weight of the anhydrous powder
0*05 grain. Before the blow-pipe this substance fused with
carbonate of soda into an oblong green mass, which became
somewhat lighter coloured by a continuance of heat, and
with borax and salt of phosphorus into a light green glass
bead. Hence, it appears to have consisted principally of
vanadic acid, mixed however with some impurity, as is
obvious from the action which was presented with car-
bonate of soda.

The liquid which had been drawn off from the insoluble
matter, as well as the washings, was concentrated and
precipitated by nitrate of silver, when a white substance
fell, becoming curdy by agitation. This precipitate was well
washed, and when dried on a watch glass by the heat of the
sand bath, weighed 3 grains exactly. It was melted by the
heat of a spirit lamp and lost 0*02 grain, leaving of dry chlo-
ride 2-98 grains. Now 18-26 : 4-5:: 2-98 : 0*734= chlorine.
After the separation of the chloride of silver, the liquid was
evaporated to dryness. The residue dissolved readily in
water, to which a few drops of nitric acid had been added,
leaving, however, a greyish powder, which proved to be
oxide of silver derived from the excess of nitrate of silver,
and was separated by filtration.

A drop of muriatic acid occasioned no precipitate in the
liquor. Through the solution, which was yellow coloured
after concentration, a current of sulphuretted hydrogen
was passed for four hours. A copious precipitation of sul-
phuret of lead ensued, and the supernatant liquid assumed
a fine transparent blue colour. The precipitate was washed
with repeated additions of water, allowing it to subside,
and then drawing off the liquid. The sulphuret of lead
weighed in a watch glass after being subjected to the heat
of the sand bath 26*02 grains. 10 grains carefully heated
over a spirit lamp, for some time after it ceased to give off
sulphur, lost 0*37 grain. By another trial 10 grains lost
0*40 grain by a heat applied twice as long, so that in the
first experiment the free sulphur had not been completely
dissipated. This makes the loss upon the whole precipitate,

1835.] and Analysis of the Vanadiate of Lead. 43

supposing it deprived of all moisture and free sulphur 1*04
grains = 24*98 grains sulphuret of lead. 9*6 grains of the
heated sulphuret were digested in nitric acid, with a drop
or two of sulphuric acid. The resulting precipitate was
thrown on a filter. After edulcoration and heating, it
weighed 11*56 grains sulphate of lead. Hence, 24*98 grains
sulphuret of lead in this case are equivalent to 30*08 grains
sulphate of lead, and in the latter are contained 22*164
grains protoxide of lead.

I have adopted the method of determining the quantity
of lead contained in the mineral, by converting the sulphur
into sulphuric acid, and obtaining the lead in the state of a
fixed salt, because it appears to be more free from objections
than when the proportion of lead is calculated from the
precipitated sulphuret of lead, whose definite composition
after exposure to a considerable temperature might be
called in question. For in this experiment which was
made with great care, the proportion of oxide if estimated
from the sulphuret would amount to 23*314 grains.

According to M. Fournet, sulphuret of lead when exposed
to a strong heat, volatilizes in the manner which is precisely
exhibited by the following formulae : 12 Pb + 24 S m (4
Pb + 8 S + (8 S)J where the portion 8 S separates at
first followed by 4 Pb + 8 S leaving 8 Pb + 8 S which
by a continued heat loses ( 2 Pb + S) + 2 Pb + 4 S*

Through the solution filtered from the sulphate of lead
a current of sulphuretted hydrogen was passed, but without
effecting any precipitation or colouration, indicating the
absence of arsenic in the mineral. I am disposed to con-
sider the impurities which have been observed in some
analyses, as proceeding from the portions subjected to ex-
amination having been mixed with the base upon which the
mineral was placed. In some of the specimens which I
examined, the phosphate and arseniate of lead, forming the
seat of the vanadiate of lead, extended above the base of the
mamillary masses towards their interior, but as they differed
very considerably in colour, the separation of the latter
from the former was easily accomplished.

The liquid after the separation of the sulphuret of lead was
evaporated. It assumed a blue colour, and when only a small
portion of fluid remained it gradually became green, and on

* Annates de Chimie et de Physique, lv. 413.

44 Dr. R. D. Thomson on the History [Jan.

being largely diluted re-assumed its blue tint. As from the
appearance of the colours in the solution, it was evident that
some of the acid had parted with a portion of its oxygen,
and been reduced to the state of oxide, it was necessary to
render the whole of a homogeneous nature. For this pur-
pose a quantity of oxalic acid was added to the liquid, and
to ensure the total conversion of acid into oxide, a current
of sulphuretted hydrogen was passed through it. The
solution became muddy and a dark precipitate appeared,
which was separated by filtration, and when heated was
completely volatilized, and was obviously sulphur. The
solution possessed now a rich blue colour. It was concen-
trated on the sand bath, in order to drive off the excess of
sulphuretted hydrogen. Nitrate of lead afforded no pre-
cipitate, indicating the absence of sulphur and phosphoric
acid. An excess of carbonate of soda was then added,
which precipitated the hydrous oxide of vanadium, in the
form of a bulky greenish brown precipitate, becoming
black by exposure to heat. It was thrown on a filter and
washed with hot water. After exposure to a red heat, it
weighed 21*39 grains. According to the numbers which
Berzelius has attached to the oxides of vanadium, we have,
in order to arrive at the quantity of acid which is equiva-
lent to this portion of oxide, the following proportion : —
10-5 : 11-5:: 21-39 : 23-436 = vanadic acid.
The results of the analysis therefore are : —

Chlorine ... -734 2-446

Protoxide of lead 22-164 73*880

Vanadic acid . . 7-031 23-436

Insoluble matter . -048 0-160

29-978 99-923.
If we view the acids as forming subsalts with the bases,
with which the numbers nearly agree, the composition of
the mineral will be

Chlorine . . .

2-475

1 atom

Lead ....

14-292

2 "

Protoxide of lead

59-361

8 "

Vanadic acid . .

23-712

4 "

Insoluble matter

0160

100-000

1835.] and Analysis of the Vanadiate of Lead. 45

or Dichloride of lead . 16-767
Divanadiateoflead . 83*073
Insoluble matter . . 0*160

100*000

equivalent to

1 atom Dichloride of lead, and
4 atoms Divanadiate of lead

and the formula, Pb* Ch. + 4 Pb* V.

Article VI.

Transmission of Heat through different Solid and Liquid
Bodies. By M. Melloni. Ann. de Chimie, lvi.

Radiating heat passes immediately, and in greater or less
quantity, through a certain class of solid and liquid bodies.
This class is not precisely identical with diaphanous bodies,
as opaque plates or such as possess only a slight trans-
parency, are more diathermanous, that is to say, more per-
meable to radiating heat than other plates completely
transparent.

Different species of calorific rays exist, which are all
emitted simultaneously, and in different proportions by
burning bodies. Rock-salt formed into a plate, and suc-
cessively exposed to rays of the same force, proceeding from
different sources, transmits immediately, the same quantity
of heat. A plate of every other diathermanous substance,
placed in the same circumstances, transmits quantities more
feebly in proportion as the temperature of the radiating
source is less elevated ; but the differences of each trans-
mission diminish in proportion to the thinness of the plate.
From whence it follows, that the different rays of heat from
different sources are intercepted in greater or less quantity,
not on the surface, and from an absorbing power, which
varies with the temperature of the source, but even in the
interior of a plate, by an absorbing power similar to that
which preserves certain kinds of light in a coloured medium.

We arrive at the same conclusion in considering the loss
which the" rays of heat from a source of high temperature
sustain in passing through the successive elements of which

46 M. Melloni on the Transmission of Heat through [Jan.

any other diathermanous plate besides rock-salt consists.
In short, if we imagine the plate to be divided into several
equal slices, and if we examine by experiments, the pro-
portion of the quantity lost, to the quantity falling upon
these slices, we shall find that the loss thus calculated,
decreases rapidly with the distance from the surface, but
the decrease becomes less sensible, so that the loss ought to
take an invariable value when the rays arrive at a certain
depth. This is precisely what happens when ordinary light
enters a coloured medium, the loss of intensity being at first
great, and gradually diminishes. A third proof of the ana-
logy which exists between the action of diathermanous
bodies upon radiating heat, and the action of coloured
media upon light, is derived from successive transmission
through heterogeneous screens. The luminous rays which
proceed from a coloured plate pass abundantly through a
second plate similarly coloured, and undergo a great ab-
sorption, in proportion as the colour of the second plate is
more or less analogous to the colour of the first.

There is only one diaphanous and colourless body, which
acts in the same manner on luminous and calorific rays.
All others allow every species of light to pass indistinctly,
but they absorb certain rays of heat, and transmit others.
Thus, we find in these bodies a true calorific colouring
power, which is invisible, and is called by the author,
diathermansie.

The following table exhibits the relative diathermanous
power of different substances : —

Rock-salt, clear, - - - - 92
Flint-glass, clear, - - - 67
Sulphuret of carbon, colourless, - 63
Chloride of sulphur, dark, - - 63
Rock-crystal - - - - 62
Rough topaz, clear-brown, - -57
Brazil topaz, clear, - - - 54
Crown-glass, clear, - - - 49
White agate, transparent, - - 35
Barytes spar - - - - 33
Oil of turpentine - - - - 31
Nut oil, yellow, - - - - 31
Oilofcolsa 30

1 835.] different Solid and Liquid Bodies. 47

Aqua marine, blue,

-

-

-

29

Borax, dull,

-

-

-

28

Tourmaline, Brazil,

-

.

-

27

Balsam Capiva

.

-

-

26

Adularia

-

-

-

24

Ether -

-

-

-

21

Gypsum

-

-

-

20

Sulphuric acid

-

-

-

17

Nitric acid, Alcohol,

Citric

acid

-

15

Alum -

-

-

-

12

Pure water -

.

-

, -

11

The colours introduced into a diaphanous medium always
diminish more or less its diathermanity ; but they do not
communicate the property of detaining certain kinds of rays
of heat. They act upon the transmission of radiating heat,
as brown substances on the transmission of light. There is
an exception in opaque green and black glass, but these two
colouring matters appear to act by modifying the diather-
manity, a quality which is independent of colouration. The
quantity of radiating heat which traverses two polarizing
plates of tourmaline does not change, when the angle of
the axes of crystallization is increased ; the rays of heat
cannot be polarized by this mode of transmission, and in this
respect they differ totally from the rays of light. They
resemble light however, in the property of refracting, which
is proved by rock salt, the only one of the diathermous
bodies capable of transmitting calorific rays from any source.

In ordinary prisms they cannot produce refraction except
upon a certain portion of radiating heat, for the glass inter-
cepts several kinds of rays of heat proceeding from very hot
sources, and absorbs almost the whole heat which is emitted
by bodies below incandescence. Hence, the doubt which
has been hitherto entertained upon the refrangibility of
obscure heat.

Article VII.

Products of the Distillation of Pit Coal. By F. F. Runge.
(Poggendorff, Annalen xxxi. 65.^

From the oil of pit coal rectified over oxide of copper, three
bases and three acids are partly separated, or are partly

48 F. F. Range on the Products [Jan.

formed, which differ in their chemical properties from any
substances hitherto observed.

BASES.

1 . Cyanol.

Cyanol (blue oil) is a volatile substance, almost destitute
of any peculiar smell, neutralizing acids and forming salts
which partly crystallize. It produces in a solution of mu-
riate of lime a blue colour, which is removed by an excess
of chlorine. The salts of cyanol dissolve in solutions of
muriate of lime, producing a fine violet blue colour, which
by free chlorine is converted into orange. They impart to
the colourless solution of the white pith of the elder and
pine wood, an intense yellow colour, which is not destroyed
by chlorine, at least under the circumstances in which other
organic colours disappear Thus, a piece of Turkey red
cotton speedily loses its colour, when after being moistened
with oxalic or tartaric acid it is immersed in a solution of
muriate of lime. Paper, cotton, linen, wool, and silk are
not coloured yellow. The effect of the salts of cyanol in
colouring pine wood is so strong, that a drop containing
only ^^o of cyanol produces a distinct yellow colour in the
wood. The yellow colouring is not imparted to the fibrous
part of the wood, but to a peculiar matter in the wood
which also exists in other species of trees. The resin has
no connexion with this colouring power.

The oil of pit coal contains a great quantity of cyanol,
whose presence is easily detected by mixing 1 part of oil
with a solution of 20 water and 1 part muriate of lime.
The oil becomes dark red and the solution assumes a blue
colour, similar in intensity and appearance to the moist
ammonia sulphate of copper. It is changed by the muriate
of lime into an acid which forms compounds possessing
a blue colour.

Cyanol is very readily detected by muriatic acid, when
coal oil is mixed with the latter in the proportion of 3
volumes to 1 . The acid becomes brown ; and a splinter of
fir wood introduced into the solution, has the yellow colour
already described communicated to it, thereby indicating
the presence of cyanol.

2. Pyrrol.

Pyrrol (red oil) in a pure state is a gaseous body possess-
ing the odour of turnips, (markochen r'ubenj and may be

1 835.] of the Distillation of Pit Coal 49

detected by dipping a stick of 'fir moistened with muriatic
acid in a vessel containing pyrrol, when it is tinged purple
red, and which like the effect of cyanol is not removed by
chlorine. Paper, &c, treated in the same manner remains
colourless. The colouring power of the compounds of pyrrol
is not less strong than that of cyanol. Nitric acid produces
in the aqueous solution of pyrrol a red colour.

It is difficult to detect pyrrol in coal oil, as the cyanol and
carbolic acid render its re-action indistinct, but it may
easily be discovered in water which has been employed to
wash common street gas, by saturating it with muriatic
acid, and dipping into it a stick of fir. A purple red colour
is occasioned.

Pyrrol forms the principal constituent of empyreumatic
ammonia, and when its peculiar smell is known, it may be
distinguished among the odours which are disengaged by the
distillation of bones and horns. Pyrrol is also contained in
tobacco oil.

3. Leucol.

Leucol (white oil) has been so termed because its re-action
is colourless. It does not produce a blue colour in muriate
of lime, nor does it communicate to fir any tinge. Leucol
is an oily substance, and is well characterized by the salts
which it forms with acids. It loses its smell by its com-
bination with acids, and forms with oxalic acid crystallized
salt.

When brought in contact with the moist skin, acetate of
Leucol emits a smell like phosphorus.

Acids.
1 . Carbolic Acid.
This acid is a colourless oily substance, sinking in water.
Its smell is extremely empyreumatic; it is caustic and
burning, and has a strong action on the skin. When the
skin is rubbed with it a feeling of burning is felt, and a
white spot is produced, which on being touched with water
becomes red, and in some days desquamates. In this re-
spect it corresponds with creosote, but differs in being acid ; in
being precipitated by acetate of lead, and in not being altered
by ammonia or the atmosphere, and in being converted by
nitric acid even diluted into a reddish brown matter.

VOL. I. E

50 F. F. Runge on the Products [Jan.

Carbolic acid dissolves in water. The solution is colour-
less and the acid is easily rendered conspicuous with nitric
acid. The water is at first yellow or orange, and afterwards
reddish brown ; a stick of fir plunged in dilute carbolic
acid, takes after being moistened with muriatic acid in half an
hour, a blue colour. The vapour of muriatic acid also tinges
shavings moistened with carbolic acid of a blue colour.
This tinge withstands the action of chlorine in a high degree.

The salts of carbolic acid are colourless, and many of
them can be crystallized ; their aqueous solutions present
the same appearances with fir as the solution of carbolic
acid. Carbolic acid precipitates albumen, prevents organic
substances from putrifying, and removes the putrid smell
of meat when digested with an aqueous solution, much
better than chlorine. The presence of carbolic acid may be
detected in coal oil by mixing it with lime water, filtering
and evaporating to the consistence of a syrup. Muriatic
acid separates impure carbolic acid from this mass, which is
impure carbolate of lime.

2. Rosolic Acid.

This acid (rose oil) is a product of the chemical decom-
position of coal oil, and contains what is remarkable, a
true pigment. It produces red and lake colours which are
equal in beauty to saffron, cochineal and madder.

Rosolic acid is a resinous mass which may be reduced to
powder, and assumes an orange yellow colour.

The principle from which rosolic acid is formed has not
yet been detected ; but its presence may be easily demon-
strated by mixing lime water with coal oil, filtering the
watery solution, and allowing it to stand for some hours.
The colourless or yellow solution now becomes red ; which
is occasioned by the precipitation of the rosolate of lime.

3. Brunolic Acid.

Brunolic acid is formed in the same way as the rosolic. It is
vitreous, shining, easily pulverized, and resembles asphal-
tum. Most of the compounds of brunolic acid are brown
and insoluble, while those of rosolic acid are red and soluble.

Besides these six substances, there is still another which
has not been obtained in a separate state.

1 835.] of the Distillation of Pit Coal , 51

Separation of Cyanol and Leucol.

Mix together and agitate 12 parts of coal oil, 2 of lime
arid 50 of water. After 6 or 8 hours pass the liquid through
a filter. It is of a brownish yellow colour and should be
distilled to one half. The liquid which comes over con-
sists of a thick oil, and a solution of it in water contains
carbolic acid in combination with ammonia, leucol, pyrrol,
and cyanol. Five distillations are required to separate the
cyanol and leucol from this mixture. The first distillation
is conducted with an excess of muriatic acid, by which
means the pyrrol and carbolic acid pass over into the receiver,
and the process is continued till the liquid passing over is no
longer red, brown, or yellow, when it is to be mixed with nitric
acid. The retort now contains a mixture of ammonia, leucol
and cyanol in union with nitric acid. This mixture possesses
a bright lyellow colour, and should now be distilled with an
excess of caustic soda. The three bases pass over into the
receiver with the water, and in the retort remains the yellow
ley with nitric acid. The matter is to be re-distilled with
an excess of acetic acid, and the process is to be continued till
the liquid passing over tinges fir wood. Acetate of cyanol
and leucol collect in the form of a colourless solution in the
receiver, while a great portion of the ammonia remains in
combination with acetic acid forming a residuum.

The acetic acid salts are now to be converted into oxalates
by distillation with oxalic acid. When the liquid which
passes over tinges wood yellow, it is a proof that the bases
are saturated. The liquid in the receiver is now to be gently
evaporated to dryness. The mass consisting of oxalates of
cyanol and leucol mixed with a little colouring matter
and ammonia, should be reduced to powder digested with
spirits, and thrown on a filter. The spirits and colouring
matter pass through the filter and leave the salts. This
digestion and filtration should be repeated until the liquid
passing through is colourless. The funnel should then be
transferred to another vessel, and spirits digested on the
salts as long as any are dissolved.

Oxalate of ammonia now remains upon the filter, and
the spirits contain in solution oxalates of cyanol and leucol,
which by the evaporation of the spirits are obtained in crys -
tals. These are to be dissolved in water and laid aside

e 2

52 F. F. Runge on the Products [Jan.

to crystallize. Fine needle crystals of oxalate of leucol first
appear, and after some time crystals also of oxalate of cyanol
make their appearance. The latter are in broad plates of
a brownish colour, and change with muriate of lime to a
violet blue, and turn wood to a yellow colour.

Should the two salts after separation not be quite pure,
they should be repeatedly dissolved in alcohol and crystal-
lized. To separate the two bases from the salts, it is only
necessary to distil them with soda ley, when they pass over
into the receiver with the vapour of the water.

Separation of Pyrrol.

It is extremely difficult to obtain pyrrol in a separate
state, in consequence of its affinity for carbolic acid. To
obviate the effects of the acid, it is best to saturate the
empyreumatic ammonia which passes over from the distilled
bones with an acid. The matter which passes into the re-
ceiver should be mixed in the first Woulf 's bottle, after be-
ing filtered, and the discharged gases absorbed by caustic
potash, or lime-water. By distillation, the pyrrol is carried
into the receiver, forming a colourless solution, which pro-
duces a purple-red in wood. To purify the pyrrol, it should
be distilled with muriatic acid, when muriate of pyrrol
passes over. When distilled with caustic ley the pyrrol
comes over pure.

' Separation of Carbolic Acid.

Agitate together 12 parts of coal-oil ; 2 of lime, and
5 of water, at intervals, for six or eight hours. The filtered
liquid should be boiled down to a fourth part, filtered after
cooling, and mixed with an excess of muriatic acid. Im-
pure carbolic acid collects at the bottom of the vessel, in
the form of a brownish oil. The supernatant liquid should
be removed, the brown oil washed with water, and subjected
to distillation. A milky liquid passes over, from which
some colourless oily drops separate, which are pure carbolic
acid. As much water is now to be added to the receiver
as will dissolve the oil, and then the liquid precipitated with
acetate of lead. Carbolate of lead is formed, which after
being well washed, is subjected to dry distillation. The car-
bolic acid collects in the receiver in the form of a yellow oil,

1835.] of the Distillation of Pit Coal. 53

which after rectification, appears as a thick liquid, con-
sisting of pure anhydrous carbolic acid. When the lead
salt is not properly dried, water passes over with the acid.
This process is necessary to free it from the heterogeneous
compounds in the coal-tar, which are ammonia, cyanol,
pyrrol, and leucol. These are removed by the boiling.
Creosote and sulphur are partly precipitated by the lead,
and the rosolic and brunolic acids remain in the retort,
while the water is separated by rectification.

Separation of Rosolic and Brunolic Acid.
The residue in the retort, after the last process, is to be
boiled with water, dissolved in spirits, and mixed with
lime-water. A rose coloured solution of rosolate of lime is
formed, and brunolate of lime remains at the bottom, as a
brown precipitate. From the rosolate of lime the rosolic
acid is separated by acetic acid, and again combined with
lime, whereby brunolic acid separates. The decomposition,
by means of acid and repeated solution, should be continued
as long as brunolic acid is observed. The rosolic acid is
then collected on a filter, and dissolved after edulcoration
and drying in alcohol. There remains on evaporation,
a vitreous, hard, orange-coloured mass. The rosolic acid
may also be separated by evaporating the solution of roso-
late of lime to the thickness of syrup, and mixing it with
J spirits. In the course of a day red crystals of the salt
appear on the sides of the glass, which are to be removed,
well washed, dissolved in water, evaporated, and treated
with acetic acid and lime-water. The brunolic acid is se-
parated from the brunolate of lime by digestion with an
excess of muriatic acid. The brunolic acid separates in
brown flakes, which for complete separation from the
rosolic acid, must be repeatedly treated with lime and acid.
The acids separated from the lime by muriatic acid, are
dissolved in soda ley, and the solution is mixed again with
muriatic acid, when a pure precipitate of brunolic acid
falls, which may be completely purified by solution in
alcohol. *

* Reichenberg.(Schweigg. Journ. lxix. 19) has drawn the following conclusions
with regard to pit coal 1 — L__of an ethereal oil is procured by distillation, with
water which is identical with petroleum. 2. Petroleum is not a product of the

54 F. F. Runge on the Products [Jan.

Article VIII.
On Pittacal, a new dye-stvff, (Poggendorff's Annalen xxxi.)

Pittacal (ttltto, and kciaaos) is a name which Reichen-
bach of Blassko has given to a substance which is obtained
from impure picamare, or from portions of the oil of beech-
tar, which are heavier than water. Dissolve them in spirits
and add a drop of barytes water. The colourless liquid
becomes immediately blue, and in five minutes assumes an
indigo shade. When tar-oil is mixed with potash-ley till
it acts, litmus is only slightly tinged acid, and the oil is
placed in a solution of barytes ; while the latter becomes
pale- red, the oil on coming in contact with the air, is
rendered blue, and in a few hours black. With dry hydrous
barytes also, the tar-oil deprived of its acid by potash,
assumes an indigo colour in the air ; and lime, magnesia,
potash, soda, ammonia, hydrous silica, give it a reddish
or yellow colour. The cause of these colours depends on
the presence of pittacal.

Pittacal is a dry, hard, brittle, dark-blue dye, of the
appearance of indigo. It is destitute of smell and taste,
and is not altered by a moderate heat ; but in a high tem-
perature carbonizing without an ammonical smell. In a
pure state, it seems rather to be suspended than to dissolve
in water. When well filtered, after some days, dark violet
flocks separate, and the solution is then completely colour-
less. Litmus, turmeric, light and air have no effect upon
it. Dilute acids, with the exception of nitric acid dissolve
it; sulphuric acid producing a violet-blue, or carmine
colour ; muriatic acid a purple-red, and acetic acid an aurora-
red. The last, by an excess of alkali, becomes again blue,
and if ammonia is the alkali employed, the solution is a
more delicate test for acids than litmus paper. In alkalies
which precipitate it from acids, even from water, it is inso-
luble. The dark-blue compound with lime, dissolves with
an aurora-red colour in acetic acid. An excess of ammonia

burning of coal in the earth. 3. Artificial petroleum has so much resemblance to
oil of turpentine, that perhaps, we may infer petroleum to have been the oil of
turpentine of ancient times. 4. Eupion and petroleum are different principles.
Rectified coal tar oil contains, with other substances, petroleum and eupion.
/>. The coal strata have not been exposed to higher temperatures. 6. Petroleum
wells appear to be the product of simple distillations of the coal strata through the
natural heat of the earth.

1 835.] of the Distillation of Pit Coal. 55

restores the blue tint. Neither alcohol, ether, nor eupion
dissolve it. Acetate of lead, salts of tin, ammonia, sulphate
of copper, and acetate of alumina, precipitate it blue, which
is not changed by an excess of ammonia. Pittacal is
therefore useful as a dye-stuff. It fastens on cotton and
linen very well with alumina and salts of tin.

Article IX.

On the acid nature of the Blood, and the distinction between
Arterial and Veinous Blood. By R. Hermann. (Bog-
gendorff's Ann. xxxi.J

Three years ago the author announced that he had dis-
covered acid in the blood, but his position was not admitted
by any chemist. In 1833, he took advantage of the pre-
sence of Dr. Stevens in Moscow to repeat his experiments.
He found 1 . That neutral tincture of litmus was coloured
red by veinous blood taken from the arm of a healthy Rus-
sian aged 31 years.

2. The coagulum being rubbed up with distilled water
boiled, and the solution containing the salts concentrated,
the residue did not alter tumeric, and had a doubtful effect
upon litmus paper.

3. 720 Gran of veinous blood fresh from the arm, were
heated with a solution of muriate of lime in a pneumatic
apparatus, and the gas extricated was collected over mer-
cury. Potash absorbed, \ Russian cubic inch carbonic acid.

6. Veinous blood was coagulated at a high temperature,
and the coagulum boiled with water and evaporated. The
concentrated residue exhibited an acid nature to tincture of
litmus, and to red litmus paper rendered red, an alkaline
state. On examination, he discovered that the distilled
water employed, contained phosphate of soda, and observed
that he could produce this paradox, by adding to phosphate
of soda some acetic acid. As the neutral phosphate of soda
has an alkaline effect upon vegetable colours, he conceives
that the acid re-action of the blood is to be attributed to the
presence of acetic acid.

6. Tincture of litmus mixed with fresh serum, was ren-
dered red. Red litmus paper became blue in the same

56 L. Gmelin and F. Tiedemanris [Jan.

liquid. When heated in a pneumatic apparatus, carbonic
acid escaped.

Dr. Stevens observed that the colouring matter of the
blood is at first dark, but at last black. In this state it
is obtained, when the coagulum is digested in distilled
water and the salts thereby removed. The dark hue of the
colouring matter is quickly changed to arterial red, when
it is brought in contact with the neutral salts, and the red
colouring matter becomes dark when added to acids, even
carbonic acid. The veinous blood contains free carbonic
acid, which can be removed, not only by exposure to the
atmosphere, but even to hydrogen at common temperatures.
By these means, he explains the difference between arterial
and veinous blood. Hermann states, that he had made simi-
lar observations previously.

It has been shewn, (Ann. de Chimie xix.J that when
arseniate or phosphate of soda appear in a solution, which
with the addition of arsenic or phosphoric acid, exhibits an
alkaline re-action, the liquid after crystallization is strongly
acid ; but if potash is the base of the crystallized salt, then
the solution is alkaline. In the first case the salt is neutral,
in the last, acid. Litmus paper moistened with a solution
of biphosphate or binarseniate of potash becomes red, dried
it becomes blue, when the salt by crystallizing takes up
the acid, which reddened the litmus paper.

Article X.

Researches on the Blood. By L. Gmelin and F.Tiedemann,
assisted by E.Mitscherlich. Poggendorffs Annalen xxxi.

Observers have differed with regard to the presence of
carbonic acid in the blood.

Vogel found that under the receiver of an air pump, lime
water was acted on by the disengaged carbonic acicl.

Scudamore obtained in the same way, by means of barytes
water, a precipitate of carbonate of barytes, equivalent to
J or ^ cubic inch of carbonic acid gas, from six ounces of
blood.

Brande procured from one ounce of arterial or veinous
blood 2 cubic inches of carbonic acid.

1835.] Researches on the Blood. 57

On the other hand, Darwin could detect no such acid,
and Dr. Davy asserts that it is neither extracted during the
spontaneous coagulation of the blood, nor by the air pump,
nor by coagulating the serum by heat, and that serum ab-
sorbs carbonic acid in greater quantity than pure water,
which would not be the case if it was charged with carbonic
acid.

Gmelin and Tiedemann examined with great care the
blood of a dog taken from the femoral-vein and artery, and
placed in different tubes under the receiver of an air pump.
The result was that neither carbonic acid nor any other
permanent gas was extricated. To ascertain the accuracy
of Davy's statement with respect to the absorbing power of
blood being greater than that of water, carbonic acid was
allowed to stand over arterial blood for 5 days, when it was
ascertained that 100 measures of blood absorb 120 of car-
bonic acid. The coagulum appeared blackish red, and the
liquid portion was extremely clear.

Since blood contains no free carbonic acid, it was neces-
sary to ascertain whether any existed in it in a combined
state. Vinegar was added to each of the kinds of blood
which had been collected, as in the former experiments, with
every precaution to ensure accuracy, and was placed under
a receiver. A quantity of carbonic acid escaped from both,
more abundantly from the veinous than the arterial. The
arterial blood mixed with vinegar, as well as the veinous
blood, left over mercury for 3 weeks, was converted into a
blackish brown mass without being separated into serum
and coagulum. About the same period, without a know-
ledge of the Heidelberg experiments, Ed. Ch. F. Stromeyer
obtained the same results.*

How do these facts agree with the present theories of
respiration 1

Lavoisier conceived that without coming in contact with
the respired air, a liquid consisting principally of carbon
and hydrogen is absorbed through the pulmonary mem-
branes into the bronchi, and is converted into carbonic acid
and water through the oxygen of the inspired air. As this

* Schweigg. Journ. fur Chem. lxiw 105.

t Memoirs de1 l'acad des Sc. An. 1790, inserted in Scherer's Journal der Chemie
x. 560.

58 L. Gmelin and F. Tiedemanns [Jan.

theory does not render it necessary to suppose free carbonic
acid in the blood, it is not at variance with the observa-
tions of Gmelin and Tiedemann, but the passage of gases
into moist animal membrane, and also the immediate contact
between air and blood cannot be well doubted of. Davy
inferred from his results that air passes through the moist
coats of the pulmonary vessels, and is taken up by the serum,
the oxygen partly forming with the carbon of the cruor car-
bonic acid, and partly combining with the cruor. When
he found that after the inspiration of hydrogen some carbonic
acid was expired, though much smaller in quantity than
after the inspiration of air, he concluded that veinous blood
contains some free carbonic acid. According to the obser-
vations already given, it appears that the arterial and
veinous blood contain no free acid but carbonic acid com-
bined with alkali. And if we suppose acetic acid to be
formed in respiration, (for we find it in the blood and in
most organic liquids which are exposed to the influence of
air in combination with alkalies), then must the veinous
blood contain more alkaline carbonate than the arterial,
when by the formation of acetic acid a portion of the alka-
line carbonates will be converted into acetates.

By means of a barytes solution in an exhausted receiver,
they estimated that 10,000 parts of arterial blood contain
8*3 of combined carbonic acid, and 10,000 parts of vein-
ous blood 12*3 of acid in the same state, being in the pro-
portion of 2 to 3.

They sum up their views of respiration in a few propo-
sitions : —

1 . That in the pulmonary cells inspired air is absorbed
into the moist membranous vessels, and is thus brought. in
contact with the blood.

2. The azote of the air is not sensibly absorbed by blood,
but almost the whole of it remains in the cells. On the
contrary, as oxygen is taken up by the blood abundantly, it
flows out of the cells into the vessels in proportion to its
absorption, and the mixture of gas remaining in the lungs
must therefore contain more azote and less oxygen than
the air.

3. The oxygen taken up by the blood combines partly
with carbon and hydrogen, and forms carbonic acid and

1835.] Researches on the Blood. 59

water, and partly unites with the solid organic compounds
contained in the blood. From these proceed acetic or lactic
acid, which combines with a portion of carbonate of soda
contained in the blood, and drives its carbonic acid into
the cells.

4. The acetate of soda loses in its course through the
different secreting organs its acetic acid, combines again
with carbonic acid after undergoing many decompositions
in its passage with the mass of blood through the body,
and enters into the lungs on its return as carbonate of soda.

Is urea contained in the blood after the extirpation of
the kidnies ?

The authors directed their attention to this point, which
it is well known has been decided in the affirmative by
Prevost and Dumas, {Ann. de Chim. xxiii.)

On the 14th January 1832, the right kidney of a dog
was removed, and in 14 days the wound healed.

The left kidney was cut out on the 11th February, and
on the 13th the animal died. The substances taken from
its body which were subjected to examination, were : 1. The
liquid vomited ; 2. The blood collected from the great
vessels, amounting to 2 ounces ; 3. The bile ; 4. The con-
tents of the small intestines. All these substances were
dried separately on the water bath, and digested with hot
water. The filtered liquid was precipitated by acetate of
lead, and the lead removed by carbonate of ammonia. The
fluid was evaporated to dryness, and treated with absolute
spirits. The residue, after evaporation, was dissolved in a
little water, and evaporated with nitric adid in a glass tube.
The solution from the blood produced, with a drop of nitric
acid, a yellowish, white crystallized precipitate, which was
collected on a filter, washed with cold water, and dried. A
portion of it heated m a platinum spoon left a trace of car-
bon ; another part, heated with potash, disengaged no am-
monia. A third portion was heated with water and car-
bonate of barytes. The mixture was digested with ab-
solute spirits, and filtered This liquid, * which was not
precipitated by sulphuric acid, gave by spontaneous eva-
poration, long colourless needles, weighing 2 milligrames.
They were soluble in water and spirits ; were dissipated by

b'0 C. Hansteen on the [Jan.

heat, and precipitated by nitric and tartaric acids ; they
consisted therefore of urea.

From the vomited matter urea was procured, but in such
small quantity as with difficulty to be appreciated. A
brownish flocky precipitate was obtained from the bile, not
completely resembling urea. No precipitate could be de-
tected in the contents of the small intestines, or from the
faeces.

Thus, the result of the German chemist's researches is,
that urea can be formed without the aid of the kidnies.
The French chemists, Vauquelin and Segalas, found no
urea in the blood of a dog 48 hours after the extirpation of
the kidnies, a circumstance which is probably to be ascribed
to the short period which elapsed between the operation
and the experiment.

No urea, or sugar of milk, in healthy blood.

Ten pounds of fresh blood from the cow, evaporated to
dryness in the water bath, were digested with hot water,
and again evaporated. The residue was taken up by water,
and precipitated by acetate of lead. The filtered liquid was
precipitated by carbonate of ammonia, and evaporated to
dryness, and the residue digested with absolute spirits.
The latter process was repeated, when by evaporation, a
combination of soda, with a fatty acid, remained.

In the solution of the residue, nitric and oxalic acid oc-
casioned no precipitate of urea, but they separated the fat
acid (acid of oil?). It should be observed that, by this
process, they had previously ascertained jfg of urea, and ~>
sugar of milk to be appreciable. It appears, therefore,
that cow's blood contains neither urea nor sugar of milk,
or at least, in extremely minute quantity.

Article XI.

On the Magnetic Intensity of the Earth. By C. Hansteen.
(Poggendorff's Ann. xxviii.)

The interesting-phenomena of the declination and inclina-
tion of the needle, lead us to the conclusion that in the
southern as well as in the northern hemisphere, there are

1835.] Magnetic Intensity of the Earth. 61

two points which appear to be the centres of the magnetic
force. If we call these magnetic poles, then the earth
possesses four poles. If the magnet is placed in the north-
ern hemisphere to the westward of one of these points, the
north pole is directed to the eastward ; and if to the east-
ward, it points to the west. When the intensity of the
degree of the inclination is investigated round the pole of
the earth in parallel circles, we find that it continues to
increase until the meridian is attained in which one of these
points lies, where it reaches its maximum.

An important point to determine with regard to the mag-
netism of the earth, is the degree of its strength or intensity.
For a long time it was disputed by the learned whether the
magnetic force was equally strong over the whole earth's
surface, or was different in different places. Mallet who
was sent in 1769, to observe the transit of Venus at Ponoi
in Russian Lapland, (Nov. Comm. Petrop. torn, xivj allowed
magnetic needles of 6" to move through an arc of 20° to 24°,
and found' that for the four first oscillations 14" less were
required than at St. Petersburg. The difference, however,
was so small that no inference could be drawn from it.

The French Academy gave instructions to the mathema-
ticians along with La Perouse in 1785 — 88, to investigate
the subject, and Lamanon* in a letter from St. Catharina
stated that he had made a number of observations; but
these as well as his subsequent ones were unfortunately
lost by the disastrous shipwreck. Captain (afterwards Ad-
miral) De Rossel made observations between 1790 and 1793
at Brest, Teneriffe, Amboyna, Java and Van Dieman's Land,
and ascertained, that if we reckon the intensity at Amboyna
in the neighbourhood of the equator unity, then it will be
at Teneriffe 1*3, at Brest 1*4, and at Van Dieman's Land T6.
Hence, it is inferred that the magnetic force at the equator
is smaller than towards the pole. But as there is a difference
of 5° of latitude between Brest and Van Dieman's Land,
the former being in 48° and the latter in 43°, and as the
intensity is greater at the latter than at the former place,
it is evident that the intensity does not alone depend on the

* This ill-fated individual who filled the situations of Natural Philosopher,
Mineralogist, and Meteorologist, was murdered hy the natives of Macuna, 11th
December, 1787. See Dillon's Voyage — Edit.

62 C. Hans teen on the Jan.]

latitude, but that under one and the same latitude in one
meridian it must be greater than in another.

In 1799 Humboldt found that the oscillations of the needle
became constantly slower towards the South as far as about
7° S. L. in Peru, where the needle remained horizontal.
The direction of the magnetic force was also horizontal.
Southward from this point it begins to increase.

The smallest intensity being taken as unity, then the
greatest force was in Mexico 1*32, and Paris 1 35.

Captains Ross and Sabine increased our data with regard
to the magnetic force, but from the observations of Parry
and Franklin, Hansteen conceives that no accurate in-
ferences can be deduced, as the needles changed their mag-
netic state. The results of these observations as well as
those of Oersted and Erikson in Germany, France and
England ; of Keilhau, Bock, and Abel in Germany, Tyrrol
and Switzerland ; of Keilhau in Spitzbergen ; of Hansteen
in Norway, Sweden, Denmark and Finland ; (Pogg. xivj
and of Sabine in Africa, have afforded materials for a mag-
netic chart upon which the intensities of the different paral-
lels may be compared by what Hansteen terms isodynamic
lines. From these it appears that the intensity in America
in the same latitudes is much greater than in Europe, and
that the isodynamic lines running parallel with the equator in
America and in the Atlantic Ocean, pass towards the North-
east, but again in Europe resume their parallelism with the
equator. The line which represents, in the northern
hemisphere, the intensity 1*5, a little to the north of
Havannah, winds to the north-east by Iceland, and then
east between Spitzbergen and the North Cape. This line
of intensity again passes southward, and incloses the other
magnetic north pole in Siberia. The definition of this line
is in conformity with the observations made by Hansteen.

Some time before Hansteen's tour in Siberia, Captain
King who was sent by the British Government to examine
the coast between Rio de Janeiro and Valparaiso, supplied
with Hansteen's apparatus for determining the intensity,
communicated many of his observations, through the
Admiralty, to Hansteen. Hansteen procured a very in-
teresting suite of data from Captain Liitke, determined
between the years 1826 and 1829, from Behring's Straits

1835.] Magnetic Intensity of the Earth 63

and Kamschatka, through the Southern Sea to the Philip-
pines. Dr. Erman of Berlin, who travelled through
Russian Asia, embarked at Kamschatka and returned by
Cape Horn, communicated also much interesting matter.
The Emperor of Russia sent a number of observers to the
Caucasus, in 1829, under professor KupfFer. who were
supplied with the proper instruments for ascertaining the
magnetic force. Captain Freycinet supplied materials
likewise.

Hansteen has fixed upon the smallest intensity observed
by Humboldt as unity, although recent researches have led
to the belief, that this is not the absolute minimum, but
that we must look for this point in Southern Africa.

The point of greatest intensity is New York, where it
amounts to 1*801. Yet this is probably not the maximum
as the direction of the line appears to indicate, that the
intensity on the West coast of Hudson's Bay may be as
high as 1*9. If we follow the 60" of parallel from Hudson's
Bay to Christiania, it will be observed, that this Latitude
cuts the different curves which indicate the intensities 1-8
1-7— 1-5— 1-4.

The isodynamic line of 1*4 which passes from Jamaica
and the Azores through England to Christiania, turns then
easterly and cuts the 60 degree of latitude at St. Peters-
burg. In this parallel a minimum of intensity is observed
between Christiania and St. Petersburg in the meridian of
Abo. Following out this parallel to the east, the intensity
is found to increase, being at Bogoslowsk 1-5, and at 120°
east from Ferro 1*7. Between 120° and 130° it attains its
maximum of 1*72, and further east it decreases, so that
about 123° it is 1*7, and in the meridian of 168° 1*6.

About 167° it reaches another minimum = 1*56 at Olu-
torskoi. The greatest intensity observed in Siberia was
detected by Lieut. Due at Wilwisk = 1*76. Hansteen in-
fers from these data, that in the northern hemisphere,
two magnetic mean points or poles exist, and that the
Western Pole, in North America, exhibits a stronger in-
tensity than the eastern one in Siberia.

The observations with respect to the magnetic force in
the southern hemisphere are extremely scanty ; those of
King and Liitke only extending along the coast of South

64 C. Hamteen on the [Jan.

America, while the whole of the Southern Atlantic, be-
tween South America and New Holland, is completely
destitute of any magnetic notice. According to De Rossel,
the intensity of Van Dieman's Land is 1*6. Tracing the
50° of latitude from South America to New Holland, we
observe that the intensity about the meredian 290° east,
must be somewhat above 1 *5, and that it decreases to 0*9
about 30° east from Ferro.

Under Van Dieman's Land, 170° east from Ferro, it ap-
pears to be 1*7. Thus, it may be inferred that in the
southern hemisphere there are two maxima of intensity
on these two points, where the declination and inclination
of the needle have indicated the existence of two magnetic
poles.

In the neighbourhood of the equator at Rio Janeiro,
Bahia, the Island of Ascension, and St. Thomas, the inten-
sity is = 0*9. Through these points, if a curve be dr^wn,
indicating this intensity, it will cut the equator at 30° east
from Ferro, and traverse Africa and the Indian Ocean near
the equator, and thence will pass through Java and Sura-
baya, where according to De Rossel it is 0*917. This
line by reflection is curved to the south as far as 50°S.L.,
and gradually reaches Bahia. If we follow a meridian
from North to South, we observe that the intensity gradu-
ally decreases, and again increases on the south of the
equator ; but they differ much in different meridians. The
intensity in the meridian 300° at New York is 1-8, (40° N. L.)
and 1-0 in 7° S. L. in Peru. In the meridian 40° the greatest
intensity is 1*55, while in 20° or 30° S. L. the intensity is
scarcely above 0*8, which appears the smaller minimum,
using the term comparatively. Hence, the smallest inten-
sity 0#8 in Africa, is to the greatest intensity 1*9 in North
America, as 1 to 19 or 1 to 2*4.

Another remark is that the intensity upon the whole, is
greater in the northern than in the southern hemisphere.
Thus we find the intensity at New York in 40° North to be
1*8, while in the same southern latitude in New Holland
the magnetic force is only 1*57. The same fact holds with
regard to the Siberian pole ; for on the borders of China
south of the Baikal sea in 50° N. L. intensity is 1*6, but
in the same southern latitude only 1*3.

1835.] * Magnetic Intensity of the Earth. 65

In the course of his investigations upon the earth's mag-
netism, Hansteen has made the interesting remark that the
Polar lights derive their origin from the four magnetic
points on the earth's surface, where the maximum of inten-
sity is observed, and that the irregular movements of the
needle during the appearance of the Northern lights, indi-
cate the most intimate connexion between them and mag-
netism. These movements of the magnet appear in the
same instant at distant places, for Hansteen observed on
the 26th August 1825, at Tornea, a sudden diminution of
the magnetic intensity, while M. Arago at Paris at the
same moment remarked a great movement in the needle,
and Holmbce at Christiania, and Herzberg at Hardanger
noticed an aurora.*

Lately it was determined at the request of Humboldt,-
that magnetic observations should be registered every hour
at Berlin, Freiberg, Petersburgh, Kasan,and at Irkutsk an
observatory is now in progress.

It is a point of some importance to attend to the relation
between the mean temperature of a place, and its position
in respect to the magnetic pole.

Mercury it is known freezes at Hudson's Bay in 55° N. L.,
which does not occur in Europe. In his journey in Siberia,
Hansteen had the mercury in his thermometer frozen many
days between Krasnojarsk and Nishne Udinsk. On the
30th of January in 55°| N.L. at Bagranowskaia, he froze
three or four pounds of mercury. At Jakutsk in June 1829,
Due and Erdman caused a well to be dug, and found the
earth frozen at 30 feet, and where a thermometer fell below
the freezing point, while in the air it was high. At Turnshansk
(65°) Hansteen found the earth frozen considerably under
the surface, while the temperature of the air was 25° R.
(56°i F.) in the month of June. At Terra del Fuego the
climate is very severe, although this island stretches from
23° to 55°, and is surrounded by the great ocean which tends
to meliorate the climate. Hence it appears that the tem-
perature in the vicinity of three of the magnetic poles, is

* The discovery of the intimate connexion which subsists between the aurora
and magnetism, was demonstrated by Dr. Dalton as early as towards the end of
the last century, so that the remark of Hansteen must be considered only as a con-
firmation of the fact ascertained by the English philosopher. — Edit.
VOL. I. F

66 Analyses of Books. [Jan.

much lower than in other places under the same latitude.
With the fourth magnetic pole in the Indian Sea, we
require the observation that there is in its neighbourhood
no other land in a more southerly latitude than 30°. This
idea of a connexion between the earth's magnetism and its
temperature, has been taken up by Sir David Brewster ;
and in a copy of Hansteen's magnetic chart published by
him in his journal, he has laid down two frigid poles in the
northern hemisphere, the one in North America, the other
to the North of Siberia. It may be asked, what is the cause
of the low temperature at these points, and why does the
magnetic pole change its condition ? The principle cause
appears to be that the greater magnetic intensity, the inferior
temperature, and the aurora borealis proceed from a peculiar
dynamic influence in the internal parts of the earth, which
is yet unknown to us. If we had observations on the annual
mean temperature for 200 years in different parts of the
earth, especially in the greater geographical latitudes, we
should possess data to determine whether or not the altera-
tions in the magnetic pole produced a change in climate,
and also if such a connexion does exist between these
phenomena.

It is remarkable that in 1825, although Hansteen had
previously paid great attention to the subject of the earth's
magnetic intensity, he had no knowledge of a system fur-
ther than that the intensity is greater at the poles than at
the equator. In 1830, he sketched out the system upon a
small part of the earth's surface, and in the same year com-
pleted his chart so far as observations allowed. Such is
the consequence of the combination of men of power and
cultivators of science.

Article XII.

ANALYSES OF BOOKS.

Traite experimental de Electricite, et du Magnetisme, et de
leurs rapports avec les Phenomenes Naturels. Par M.
Becquerel, torn. i. Paris, 1834.

This is an interesting work, and forms a concise digest of the facts
which have been ascertained in the important branch of science of
which it treats.

1835.] BecquereTs Traitt Experimental, Sfc. 07

The author divides the work into two parts. In the first division
he considers the general properties of the electric principle in rest
and motion, as well as those relating to magnetism. In the second,
he treats of their relations with chemical affinity, and their applica-
tion to phospherescence, to spontaneous actions and other phenomena,
which seem to derive their origin from electricity. In the histo-
rical preface with which the work commences, three periods are spe-
cified as forming distinct eras in the science.

The first period begins with Thales, 600 years before the Christian
era, the first individual as far as we can learn from history, who
observed the power of attracting light bodies, which amber acquires
when exposed to friction, and terminates with the great discovery of
Galvani in 1790. The second period extends from this discovery
(inclusive) to 1820, when Oersted demonstrated the intimate con-
nexion subsisting between electricity and magnetism. The third
period brings the history of electricity and magnetism down to the
present day.

Passing over this division of the treatise, which we consider well
worth perusal, we proceed to present a short outline of the applica-
tions of electricity to the explanation of natural phenomena.

Phosphor esence, according to the facts which have been ascer-
tained in reference to it, is produced in particular bodies by : 1 . Heat,
as occurs in the diamond, when submitted to a considerable tempera-
ture, a fact observed by Boyle in 1 663, and in anhydrous nitrate of
lime, and likewise in fused muriate of lime. Many other bodies ex-
hibit this phenomenon in these circumstances, as shells, sulphate of
lime, caustic potash, soda, and chalk. 2. Percussion, as adularia
when struck in such a manner as to form fissures in the internal
substance chalk. 3. Friction. 4. Exposure to the light of the
sun, as in diamonds which lose this property by calcination, tubes
of glass, &c. 5. Compression, which excites a luminous appear-
ance in all bodies, water especially when compressed in a tube
with a piston exhibits this property, and also olive oil, alcohol, ether,
acetic acid, sulphur, sulphate of magnesia, nitrate of potash, black
oxide of manganese, mica vegetable charcoal, oxygen and common
air. According to Pearsall, chlorophane which loses its phospho-
rescent property by heat, resumes this quality by exposing it to the
action of a Leyden phial.

This phenomenon, which is familiarly illustrated during the expo-
sure to heat of fluor spar in a dark situation, and in the putrefaction
of fishes, admits of explanation on the principle that light accom-
panies the disengagement of electricity only when the latter possesses
sufficient tension, and that it is owing either to the separation of the
two electricities at the moment when they are disengaged, or to their
action upon the surrounding bodies, in order to form a neutral fluid.
When the two electricities separate by friction the chemical action
of two bodies which are in contact, it is impossible to collect the two
fluids unless the two bodies are not good conductors, because they
are so rapidly reinstated, that the two surfaces cannot accumulate
enough of electricity to procure for them, on account of the conduct-
ing power of the body, enough of tension to produce the luminous

f2

68 Analyses of Books. [Jan.

phenomena. Thus good conductors are not phosphorescent, but bad
conductors are possessed peculiarly of the property of phosphorescence.

Heat in delating the ultimate particles of eertain bodies, deprives
them of their equilibrium, and produces electricity ; but in some cir-
cumstances a change in the state of their aggregation is occasioned by
the same agency, which is a* very productive cause of electricity.

State of the globe at its formation. — This is delicate ground to
speculate on. M. Becquerel's explanations do not appear to be suited
to the object to which they refer, but on the contrary, are bold and
even rash. For the sake, however, of giving some insight into the
theories which are now emanating from chemical geology upon such
an interesting topic, we shall proceed a little farther with the sub-
ject. Geologists in general consider that the sedimentary deposits
whose layers are more or less inclined to the horizon, have been dis-
placed by subterraneous agency, which has acted after their formation,
and given to the different elevation on the globe particular characters.
These causes having acted at different epochs, it is obvious that several
classes of mountains have been elevated which are distinguished by the
direction of their course. Von Buch has shewn that the soil of Ger-
many may be divided into four systems, and Elie de Boumont has
endeavoured to classify the successive elevation of the European
mountain ranges by referring them to twelve epochs. In the Alps
the secondary and tertiary beds are inclined, while in the Vosges and
England all the formations superior to the coal are nearly horizontal,
from which circumstance and others of a similar nature, Beaumont
has obtained an argument of no small importance to his theory. The
systems which he enumerates are : 1. of Westmoreland and Hunds-
ruck. 2. Of Ballon (Vosges) and Boccage (Calvados.) 3. Of the
North of England. 4. Of Pays-Bas and S. Wales. 5. Of the
Rhine. 6. Of Thuringerwald, Bohmerwald and Morvan. 7* Of
Mount Piles, Cote d' or and Erzgebrige. 8. Of Mount Viso. 9. Of
the Pyrenees. 10. Of Corsica and Sardinia. 11. Of the E. Alps.
12. Of the principal chain of the Alps from Valais to Austria.

Gneiss and granite are the rocks which have disturbed the newer
formations, and protrude through them in the form of peaks If we
could determine in what state these important constituents of the
globe existed in the internal part of the earth, and with what they
were associated, a great step would be gained. Our author how-
ever has not waited for any accurate knowledge on this head, but in
company with M. Ampere has proceeded to theorize.

He considers the earth to have been primitively in a gaseous
state. By the radiation of the heat into the regions of space the
temperature of this mass of elastic matter was gradually diminished,
condensing the different bodies according to their refractoriness and
density. The metals would be first deposited, and would form an
immense bath in the centre, from which an enormous heat would
emanate, to retard the condensation of the other vapours. The first
nucleus would be formed of unoxidized metals, after which less
fusible substances would be deposited, producing new compounds.
Potassium and sodium, in consequence of their strong affinities for
a number of bodies, are convenient substances for effecting powerful

1835.] BecquereVs Traitt Experimental, fyc. 69

results in these successive changes. The temperature continuing to
lower, oxygen, hydrogen, and non-metallic bodies would act upon
each other, and give origin to water and acids, which would produce
a multitude of combinations. The first re-action upon the alloys of
potassium with the more combustible metals would be strong, and
give rise to heat sufficient to volatilize again many of the condensed
bodies. At this period, the saline and earthy bases would be formed,
and the oxygen having been absorbed by a great number of bodies,
much azote would remain, in consequence of its weak affinity for the
bases. As the diminution of temperature always continued, the
crust formed over the metallic bath would occupy less space, and
give rise to contractions and elevations which would produce the
mountains according to Beaumont's explanation. The waters he
conceives which began at first to cover the earth's surface were
strongly acidulated, and in filtering through fissures in the crust
would be accumulated in cavities, from whence they would fall on
the fused metals, and give rise to earthquakes and volcanoes. These
actions being frequently renewed the crust of the earth would in-
crease in thickness, and would allow liquids to pass with greater
difficulty, and eruptions would then become less frequent, in conse-
quence of the diminution of atmospheric temperature. Then began
organized beings to appear in the form of monocotyledonous plants
of colossal dimensions, flourishing in an atmosphere possessing a much
greater proportion of carbonic acid than now exists in it, an idea
which is strengthened by the circumstance of the contemporaneous
limestone containing shells of molluscous animals.

In the last of the transition formations we meet with remains of
zoophytes and molluscous animals, then fishes, reptiles, birds, and
mammiferous animals. The air being purified, and the earth having
acquired greater stability, man appeared to rule over the hitherto
spiritless globe. The world being thus formed, disintegration of the
elevated matter, by electric, chemical, and other agencies, affords an
explanation of the newer deposits.

Volcanoes. — The products of Vesuvius are lava, sometimes gra-
nite, mica slate, sulphurous and muriatic acid gases, sometimes car-
bonic, rarely azote. In the fissures of the rocks are found common
salt, sal ammoniac, chlorides of copper and iron, boric acid, sulphur,
sulphuret of arsenic. The volcanoes of America emit gases, differing
from those of Vesuvius ; Talima affords vapour of water, carbonic
acid gas, and sulphuretted hydrogen, as well as those of Purace,
Pasto6, and Tuqueres. Humboldt relates that a shower of fish was
discharged by a Mexican volcano. The most plausible theory con-
siders these phenomena to be connected with a communication existing
between the seats of volcanoes and the waters of the ocean ; for the
epoch when these eruptions were common, was when the communi-
cation was more easy. Then was effected that great depression in
the West of Asia, whose lowest level is the Caspian Sea, and Lake
Aral, (50 to 30 toises below the surface of the ocean) which extends
from Saratov to Orenburgh, and appears to have an intimate con-
nexion with the elevation of Caucasus and Hindoukha. This bason
or crater resembles Hipparchus, Archimedes and Ptolomy, on the
surface of the Moon, which are thirty leagues in diameter.

70 Analyses of Books. [Jan.

Terrestrial Heat. — The facts with which we are at present ac-
quainted tend to prove that every place on the surface of the globe
has an invariable mean temperature. The mean temperature of the
equator is between 81*5 and 82° 4, being modified by the great extent
of the equatorial seas. The entrepid northern navigators have found
a great difference, in the same latitude, between the temperatures
on land and in the open sea. At Melville Id- the mean heat was
— 18° 5C, while in the open sea it was — 8° 3. Calculating from
these data, the temperature of the pole would be — 25° or — 30°.

It is remarkable that those places which are situated on the same
isothermal line do not present the same vegetable productions.
Hence, some have divided climates into constant, where the tem-
perature is steady during the year, variable, and excessive, which
comprehend those where the differences are very great. Cassini, in
1671, had remarked that under the Observatory of Paris, the tem-
perature was steady during the whole year ; and the observation has
been confirmed, the heat being determined to be 11° 82 (53° F.)
Cordier has inferred, from his researches on the temperature towards
the interior of the earth, that below a particular point where the
temperature is steady, the heat increases with the depth, to the
amount of 1° for every 25 to 30 metres.

M. Fourier has demonstrated that the cooling of the globe, if
such a fact is admitted, must be very slow, being less than ^-^0
of a centigrade degree for a century ; and he has drawn these conse-
quences : 1. All the heat below a particular point where the tem-
perature is steady, has been possessed by the earth from its com-
mencement. 2. This heat is intense in the nucleus, and at a certain
distance from the centre it begins to diminish by regular laws up to
the steady point. 3. The internal equilibrium changes with time,
and will continue to alter until the whole heat is dissipated, but this
process is going on in an extremely tardy manner. 4. The heat de-
rived from the interior cannot appreciably modify that of the surface.

Humboldt has observed that in Mexico the decrease of tempera-
ture is not proportional to the height ; and Boussingault has found
that in twenty-three years the sources of the Mariara have increased
in temperature from 59° 3 C. to 64° ; and those of Strincheras, from
90° 4 to 92° 2. The diurnal variation of the thermometer at the
equator on the sea is 1° to 2° , while on the continent it is 5° to 6°.
At the equator the ocean's surface is hotter than the air ; but at the
poles the reverse is the case.* Between the tropics, the heat dimi-
nishes with the depth ; on the polar seas it diminishes as we descend.

Such are some of the principal circumstances bearing upon terres-
trial heat with which we are at present acquainted .

The formations of which the globe is composed is the next subject
which our author takes up, after speculating upon the method in which
it was consolidated, applying known agents to the explanation of vol-
canic phenomena, and tracing out a sketch of the facts which have
been ascertained in reference to terrestrial heat. He first notices allu-

* In lat. 2° 9' N., long. 20° 38 W., I found the temperature of the Atlantic
Ocean 79<>r>, that of the air being 79° ; and in 2*20 S.L^ 59<>5' E.L. the thermo-
meter stood in the air at 80°, and in the Indian Ocean at 88°6. — Edit.

1835.] BecquereVs Traitt Experimental, 6fc. 71

vial deposits which are in process of formation, consisting of peat,
marls, gravel, stalactities, pisolites, and travertines. He then passes
to mineral waters or salt springs, which are so influential in bringing
up from considerable depths soluble salts. In these are found car-
bonate of soda, borax, alum, deposited in the fissures of rocks, nitrate
of soda as in Peru, nitrates of potash, lime and magnesia, as in
Hungary, Ukraine, Podolia, &c; sulphate of magnesia, sulphate and
carbonate of lime. These substances seem to be deposited by the
water when traversing fissures of rocks, and which action is more
energetic in proportion to the increase of temperature. The quantity
of salts brought by these means is much greater than one without
consideration would infer. The Carlsbad water discharges annually
746,884 pounds of carbonate of soda, and 132,923 pounds of sulphate
of soda, in addition to numerous other substances. Now, the ope-
ration of solution must be effected by the electro-chemical action of
the thermal waters upon the rocks, at a greater or less distance from
the earth's surface.

The origin of the ocean's saltness has attracted the attention of
many, but little light has been hitherto thrown on this subject. It
is, however, apparent that the quantity of saline matter varies on
account of the proximity of rivers ; thus, the Baltic and the Black
Sea are weaker than the ocean, and still more so than the
Mediterranean.

From Boussingault's observations, it appears that the temperature
of hot springs diminishes with the height ; and hence, he infers that
they have their origin in the volcanic fires. He found that the
mineral waters near volcanoes, contained sulphuretted hydrogen and
carbonic acid, the identical gases which were detected among the
vapours emitted from their corresponding volcanoes. The carbonic
acid he considers as the product of the calcination of carbonate of
lime and soda, or of their re-action upon silicious or aluminous sub-
"stances, and the sulphuretted hydrogen may derive its origin from
the re-action of the vapour of water upon sulphuret of sodium.

The rocks of the tertiary formations are in general calcareous and
silicious with a predominance of magnesia, especially where the
gypsum appears. Under this head are included the new formations
characterized so happily by Mr. Lyell, and to whose work it is proper
to refer the reader for accurate and interesting information.

The secondary rocks include the chalk, which is the result of
chemical precipitation, the oolites, a sedimentary group, as well as
the muschelkalk and zechstein.

In the transition rocks, the coal, according to Deluc, has been
formed at a slight elevation above the sea like turf, and has been
submerged and covered by the sand of the ocean. If these waters
are supposed to have borne along with them earthy matter of an
elevated temperature, an explanation will be afforded for the absence
of animals in these rocks. The water under which the coal was
formed must have possessed the property of holding iron in solution,
as is apparent from the quantity of iron-stone which usually accom-
panies coal. Hence, the atmospheric pressure may have been greater.
The formations which derive their origin from the greatest depths,
are obviously granite, mica slate, and the rocks usually termed pri-

72 A nalyses of Books . [Jan.

mary. The porphyries, euphotides, or compounds of jade and dial-
lage, serpentines, black porphyry, or ophites and dolomites, are more
variable in their position.

Among volcanic products the trachites are considered most an-
cient, and are sometimes stratified. The traps, or basalts afford
many minerals ; the lava group contain also many species. Both
iEtna and Vesuvius have been known to eject granite, in addition
to the pulverulent and solid matter which they continue to emit at
intervals.

Decomposition of Rocks — Veins. — According to Becquerel,
veins are not to be considered as products of one general cause, but
of a concurrence of several causes. The veins in the most ancient
rocks are smaller than in the newer rocks, the largest existing in the
schists and transition limestones. Werner considered that rocks were
decomposed by two acids: 1. By carbonic acid as when granite
and gneiss or felspar alone are decomposed and form kaolin. 2. Sul-
phuric acid derived from pyrites, as in veins of felspar, mica, and
amphibole. Arsenic acid he considered produced a similar effect.

M. Fournet, who has paid much attention to veins, distinguishes
two kinds : those of igneous origin, such as porphyries, trachites, &c.
in which the silica has formed combinations by means of heat ; and
those of aqueous origin, as we see illustrated in mineral waters. To
exemplify the former, he cites those instances where sulphuret of
iron, silica, and iron pyrites have been deposited upon the fragments
of primitive rocks, and with regard to the latter, he mentions cases
where talc and mica are changed into a grey substance, and granites
where felspar is altered into kaolin, likewise talcose schists where
steatite is isolated in veins. In the veins of Pont Gibaud, he ob-
served four other epochs. At the second period new branches were
formed, which were filled with secondary and tertiary products,
especially quartz, but likewise sulphurets, which have formed alter-
nating zones of pyrites, galena, and hyaline quartz in small crystals.
A third period distinguishes a dilatation which disturbed the sources
of the galena and introduced solutions of sulphate of barytes. At
the fourth epoch, the incrusting power of these sources appears to
have been enfeebled, when pyrites and minute veins of carbonates
were deposited. The fifth epoch was contemporaneous with the
basaltic eruptions. It is obvious, that for an explanation of the mode
in which these veins are tilled, we must have recourse to chemistry.
Thus, hydrate of iron proceeds from the decomposition of pyrites;
the powder of hydrous oxide is derived from the decomposition of the
carbonate, galena is gradually converted into a black pulverulent
substance, which gives birth to black and white carbonate. With
regard to the formation of rock-salt, Dumas has observed that in one
variety of it which decrepitated when placed in water, the cause
was attributable to hydrogen which condensed in its cavities.

Granite. — Saussure attributed the decomposition of this rock to a
corrosive juice which dissolved the gluten uniting all its parts.
Vanquelin and Alluan traced the cause to disintegration of the rock,
and the removal of the alkali in the felspar by water. But Berthier
has shewn that silica as well as potash is removed, a silicate of

1835.] BecquereVs Traitt Experimental, 8fc. 73

potash disappearing and silicate of alumina remaining. Felspar is
probably one of those bodies whose particles are placed in such inti-
mate union that acids have no effect upon it until it be exposed to
electro-chemical agency. Fournet has observed three preliminary
stages in the decomposition of granite. 1. A superior zone of a red
or yellow colour, indicating the peroxidation of iron. 2. A middle
zone of a deep green colour. 3. An inferior zone, presenting all
the characters of a perfect granite, but falling to pieces when touched.
He accounts for the successive decomposition from the surface, inter-
nally to dimorphism, which has changed their crystalline texture
like arragonites and laumonites. Gustav. Rose has produced
pyroxene and amphibole as instances of this dimorphism, of which
some result from rapid, others from slow cooling. The theory of the
felspar decomposition Fournet sums up shortly. The iron is per-
oxidized, carbonic acid is absorbed and takes the place of the silica,
which, being set at liberty in a gelatinous state, dissolves in water,
or alkaline carbonates, and gives origin to crystals of hyaline quartz,
iorites, agates, opal, calcedony, and silicates, as chabasite, mesotype.

This theory, however, rests upon two suppositions which have not
yet been demonstrated. 1. That igneous rocks do not acquire a state
of permanent equilibrium, and that they exhibit in the course of time
an effect of dimorphism, and 2. that carbonic acid is absorbed by
these rocks. The latter appears to be strongly exhibited in Auvergne,
where numerous mineral springs, which escape from granite fissures,
act upon the rocks, and form small irregular basons which they fill
with hydrous peroxide of iron.

Sparry iron ore. — Granite before it decomposes disintegrates,
but the iron ore retains its form, and yet changes its chemical nature.
Becquerel has examined the process of the decomposition of this
mineral in Isere, and he has found it entire when preserved from the
contact of air and water. In Dauphine it is decomposed in such a
manner as to give out heat and light, which burst into flame and
continue to burn. The inhabitants regard the presence of these
flames as a decided proof of the existence of rich mines of this
mineral. The mineral contains carbonate of manganese and mag-
nesia. The iron and manganese change into hydrates, lose their
carbonic acid which combines with the magnesia, and renders it
soluble in water. Water is decomposed to afford oxygen to the
hydrate, and the hydrogen inflames after overcoming an immense
pressure.

According to Chapert, when some of the minerals accompanying
this iron ore are roasted, and left to spontaneous action, after some
days, sulphate of magnesia and iron, and carbonate of copper appear,
facts of great importance in electro-chemistry. Four kinds of pyrites
accompany this ore, which give origin, to 1 . Neutral sulphate of iron.
2. Earthy sulphate, a yellow substance, resinous or earthy. 3. Ochre
proceeding from the action of air upon the neutral sulphate ; besides,
sulphate of iron and alumina, manganese, lime, zinc, &c.

Lavas. — Granite decomposes readily in contact with bay-salt, as
is evinced in Scotland and Clermont. The facility of the decompo-
sition of lavas varies with their composition ; thus the pyroxenic rocks
of Auvergne decay more rapidly than the Labradore masses of

74 Analyses of Books. [Jan.

Como. Wacke is a rock formed by the action of water upon these
rocks, and contains calcareous spar, zeolites and piperine.

There is reason to think that the crystals which are found in bay-
salts, have been deposited after the consolidation of the rocks in which
they are found, because most of them are altered by a strong heat,
and lose their water of crystallization. Fournet attributes the for-
mation of zeolites to the transportation of the elements by water from
the neighbouring rocks.

Organic matter. — The mode in which organic matter undergoes
decomposition has not been much studied, but a few curious facts
have been ascertained. Davy found the manuscripts of Herculaneum
converted into a kind of turf, the leaves being united into a single
mass by a peculiar substance, formed by the chemical changes of the
vegetable matter. The guano in Peru is found in deposits of 50 or
60 feet deep, and is formed of the excrement of herons which inhabit
the coast.

Necker de Saussure has observed the teeth of the ursus spil&us
in the mines of Carmiola, corroded as if by an acid. Turpin has
noticed the egg of the garden snail to be covered on the interior
surface of its envelope, with rhombohedral crystals of carbonate of
lime. The cellular tissue of the cactus, and the medullary tissue of
palms contain oxalate of lime in crystals.

Nitrification. — When distilled water is placed over plates of
iron, lead, zinc, or tin, ammonia is formed in consequence of the
combination of the hydrogen of the water with the azote of the air.

Vanquelin found ammonia in some rusty spots on a sabre, which
had been employed by an assassin, and that other traces presented the
same substance. Protoxide of iron, yenite, earthy oxide of iron
heated in a tube, give out ammonia. Ammonia was detected in the
ferruginous water of Passy after evaporation. Boussingault has
observed it likewise in oxidized iron by taking a fragment of it,
treating it with dilute muriatic acid, evaporating the washings, and
heating the residue with quick-lime in a tube, using the precaution
to moisten them with water. Faraday obtained ammonia, by heating
zinc foil in a glass tube with potash. The experiment succeeded
even in hydrogen gas. Potassium, iron, tin, lead, and arsenic like-
wise afford much of it, with soda, lime, barytes or potash. The
alkalies alone do not yield it.

The formation of saltpetre has long been a subject of interest.
Dumas conceives that the presence of organic matter is not essential.
Claubry attributes its production to the action of an acid moisture
upon carbonate of lime.

Fournet thinks that nitric acid may be formed without the pre-
sence of organic matter, by the re-action alone of the elements of air
and vapour of water. For according to Saussure, oxygen is more
condensable by porous bodies than azote, in the proportion of 65 to
4'00 ; and Gay Lussac and Humboldt have observed that air dis-
engaged from water by boiling, contains more oxygen in proportion
to the slowness of its extrication. The result is that oxygen is not
only retained with a greater power, but the composition of the last
portions of the air approaches protoxide of azote. Fournet has con-
cluded, that the united action of porous bodies and of water upon the

1835] BecquereVs Traite Experimental, Sfc. 75

elements of air, would produce at first, protoxide of azote ; then
nitrate of ammonia, which when decomposed, resolves itself into
protoxide of azote and vapour of water. The nitrate acts upon the
alkaline carbonates and forms nitrate of potash, while the ammonia
is disengaged in union with carbonic acid. He applies his theory to
explain the production of nitrate of ammonia, dissolved in rain by the
electric agency. He concludes by observing, that in every electric
chemical action, however feeble it may be, if water is decomposed in
contact with air, ammonia is formed.

Last geological revolution. — Becquerel endeavours to calculate
this period, by a method which it must be allowed is extremely
vague. He finds that the cathedral of Limoges, which has stood for
four centuries, and is built of granite, is decomposed on that side
where the winds and the rain beat to the depth of 3J lines, and that
the rock in situ is disintegrated to the depth of 5 feet or 720 lines.
If both have progressed at the same rate, he conceives that the rock
in its natural place must have been decomposing for above 82,000
years.

Terrestrial magnetism. — From the facts which have been
brought forward by Humboldt and others, it appears proper, that
experiments should be made upon the magnetism of the rocks, which
constitute the formations of the country in which the experimenter is
placed, or at least to determine at what point the extent of oscilla-
tions diminishes without changing their number.

Atmospheric electricity. — Saussure has shewn that in summer
the electricity of the calm air is much weaker than in winter ; and
that the apparent force of electricity, depends not so much on the
absolute height of the place of observation as upon the relative
height, or on the insulation of the place. Disseminated as this prin-
ciple is through the medium of the vapour of water, it is highly
probable that it exercises no inconsiderable effect on the plants and
animals which are of necessity subjected to its influence.

Becquerel terminates the first volume of his work, with some
remarks upon the agencies by which the decomposition of some rocks
and the formation of some insoluble compounds may be explained,
which comprehends a recapitulation of some points. But he shews
more particularly, how electro-chemical action operates in producing
many minerals. Phosphate of iron in mines and crevices he con-
siders to be the result of the action of electricity, which is disengaged
during the peroxidation of iron and the decomposition of organic
matter. The formation of the chromate of lead as it exists native,
may be imitated by treating a solution of nitrate of lead with chalk
and then with chromate of potash. In the course of a montli or two,
crystals of chromate of lead were observed on the surface of the
chalk. By mixing sub-nitrate of copper, with arseniate of copper,
a double arseniate of copper and ammonia, and of arseniate of lime and
ammonia is formed. The re-action of bi-carbonate of soda upon
gypsum gives origin to carbonate of lime which crystallizes, sul-
phate of soda remaining in solution.

A supplementary chapter is appended, containing a short outline
of the interesting electro- chemical researches of Dr. Faraday.

76 Scientific Intelligence. [Jan.

Article XIII.

SCIENTIFIC INTELLIGENCE, &C.

I. — Method of destroying Mice Sfc, in their lurking places.
{Ann. de Chirn. xlix. 437.)

M. Thenard, in 1832, submitted to the Academy of Sciences apian
for destroying noxious animals, when they have taken refuge in their
hiding places. The instrument of destruction is sulphuretted hydro-
gen, which he had remarked to be peculiarly deleterious to animal
life. Animals when allowed to breathe the pure gas fall down as if
struck with a bullet. Even when considerably diluted with atmos-
pheric air, the effects are deadly. A horse dies in less than a minute,
in air containing ^0 of this gas. A dog of moderate size is speedily
killed in air containing ^ while a greenfinch expires in a few seconds
in air possessing ?~r of sulphuretted hydrogen. Influenced by these
facts, the French chemist proposed the employment of this gas to
several individuals for the purpose of extirpating noxious vermin,
but his suggestions being treated with indifference, he determined to
put the method in practice by his own experiments.

His first trial was in an apartment infested by rats, which shewed
themselves occasionally during the day, and at night were actively
engaged in plundering a chest of oats, to which they had access
through an aperture of their own formation. The holes by which
theji retreated amounting to 18 in number, Thenard adapted to each
of them in succession retorts capable of containing half a pint mea-
sure, by introducing the beak of the retort and filling up the interval
round its neck with plaster. Sulphuret of iron was deposited in the
retort, formed from a mixture of iron filings sulphur and water, and
dilute sulphuric acid was introduced by means of a tube placed in
the tubulure. The sulphuretted hydrogen was disengaged with
great rapidity, and in a few minutes not a rat remained alive in the
building. His next experiment was in an old abbey where he was
equally successful, and having opened up part of the wall he found
many dead rats. He recommends the application of this method to the
destruction of moles, foxes, and all animals which cannot be extirpated
by the usual means. Thenard then gives popular directions for the
formation of the materials required to produce the gas.

Mix 4 parts of iron filings, 3 parts flowers of sulphur in a mortar
with a pestle. Place the mixture in a convenient vessel, and
moisten it with 4 parts of boiling water, stirring it with a piece of
wood or glass. Add gradually afterwards 4 parts more of water, and
introduce it into the retort. Pour upon the mixture common oil of
vitriol diluted with five times its volume of water, and continue to
add it gradually till the effervescence ceases. Should any of the gas
escape into the apartment and occasion inconvenience, it may be re-
moved by dropping a little sulphuric acid upon bleaching powder.
The holes should be closed immediately, to prevent the disagreeable
effects of the putrefaction of the carcases of the animals which have
thus been destroyed.

1835.] Scientific Intelligence. 77

II. — Fresh Water formation in Gyeece with Lignites. By
M.Theodore Virlet. (Annales des Sciences Naturelles,
torn. xxx. 160.)

In 1830 a report was very generally spread of the discovery of coal
in Greece. M. Theodore Virlet, who was in that country soon after
the coal was said to have been observed, proceeded to the spot for the
purpose of examining into the truth of the report. He visited the
Sporades Septentrionales or Devil's Archipelago, situated at the
mouth of the Gulfs of Voloand Salonica, near the coasts of Thessaly
and Macedonia, where it was said coal existed. He found the islands
of Skiathos, Skanzoura, and Diodelphia to consist of primitive rocks,
those of Xero, Xera, Panagia, Jaoura, Piperi, &c. to belong to a
calcareous formation. In the island of Skopelos the latter rests on
clay slate, and in some respects agrees with the transition limestone,
but the existence of a number of fossils and especially Hippurites
semicostellata, proves its distinct nature. Tornatella prisca, and
Turritella antiqua Desh are likewise met with.

Iliodroma is a long, narrow, mountainous island which consists of
three formations : 1. Mica-slate, clay-slate and limestone. 2. Blue
and grey limestone. 3. A fresh water tertiary formation containing
lignites which occupies half of the surface of the island, and was mis-
taken for coal. The lower portion is situated 200 or 300 metres above
the sea, and is constituted of blue or green marls with a great deposit
of fresh water and land shells belonging chiefly to the genera Planor-
biSjPaludina, Helix. Over these marls lie thin strata of marly lime-
stone without fossils, but containing an irregular bed about 2 feet
(Paris) thick of lignite, in general mixed with clay and shells. Above
the lignite grey marls occur, filled with the debris of fossil vegetables.
The whole of the formation is about 190 English feet in thickness.
Among the fossils obtained from this formation, the most numerous
belonged to what M. Adolphe Brongniart who examined it, has
termed Taxodium Europeeum. It has also been found at Como-
thau in Bohemia, and at CEningen near the lake of Constance. It
belongs to the order Corniferae, and is characterized by long slender
branches, subglobose cones, with leaves spiral or sometimes arranged
in three rows.

Virlet considers this formation more ancient than that of CEningen,
and contemporaneous with the dislocation of strata which produced
the Dardanelles, and with the corresponding formation in Switzer-
land, and the marine deposit of Gompholites in the Morea.

III. — Oil extracted from the Spirit of Wine of Potatoes.

By M.J. Dumas. (Ann. de Chimie, lvi.314.)
Previous to rectification, spirit of wine whether it be obtained
from malt or potatoes, possesses a peculiar taste and smell which is
removed by distillation frequently repeated. It has been long known
that these properties depend on a peculiar oil, and its presence was
first detected by Scheele. Fourcroy and Vauquelin proved that the
oil was not a product of fermentation, but that it existed in grain
and could be separated by treating it with water, and taking up the

78 Scientific Intelligence. [Jan.

oil from the liquid by alcohol. M. Payen has shewn that the seat
of this oil is in the tegumentary part of the fecula of potatoes. Those
who have examined the oil proceeding from the spirit of barley, de-
scribe it as capable of crystallization, volatilizing with difficulty, un-
dergoing alterations by distillation, and staining paper permanently.
Pelletan found on the contrary, the oil from the spirit of potatoes to
be a true essential oil. Dumas examined a specimen from the manu-
factory of Dubrunfaut; it possessed a reddish yellow colour, and a very
disagreeable smell. When one breathes the air charged with it,
nausea and head-ache are produced. Carbonate of potash diminishes
the odour considerably, and when distilled with it renders it analogous
to that of nitric ether. In order to free it entirely from alcohol, it is
necessary to distil cautiously, and obtain a residue of pure oil boiling at
130° (266° F.) or 132° (269°) the alcohol passing over first. Dumas
suggests that although bearing some affinity to alcohol and ether, it
may belong to the family of camphors. The density of its vapour is
3*147, or calculating from the composition 3*072. It consists of: —

Carbon .... 68*6

Hydrogen ... 13*6

Oxygen .... 17*8

IV. — Mode"of Detecting some Organic Acids. By H. Rose,
(Poggendorff's Annalen. xxxi.)

Tartaric, racemic, citric, and malic acids may be readily detected in
the following manner : dissolve them in as small a quantity of water
as possible, and add to the solution an excess of lime water, so that
reddened litmus paper may become blue.

Tartaric and racemic acids form a precipitate in the cold state.
That produced by the tartaric acid dissolves completely in a small
quantity of a solution of ammonia, while that of the racemic acid re-
mains insoluble. Both acids can likewise be readily distinguished
by their treatment with a solution of sulphate of lime, when after
some time racemate of lime is deposited, while the solution of tartaric
acid is not affected.

The solution of citric acid yields no precipitate with lime water in
the cold state, but when heated, a considerable precipitation occurs.
If a small quantity of a very dilute solution of citric acid is mixed
with lime water, a precipitate falls by boiling, which is taken up by
allowing the solution to cool. The solution of malic acid occasions
no precipitate with lime water, either in the cold or by boiling. For
these experiments completely saturated lime water, should be em-
ployed.

V. — Iron Mine of Rancie. By M. Dufrenoy.
(Ann. des Sciences Naturelles, xxx. 59.)

The formation of Vic Dessos, consisting of a compound of white
saccharoid limestone, black compact limestone, shistose limestone,
belongs to the inferior portion of the Jura formations.

The Hematite of Rancie contained in this deposit, is disposed in
layers, and is connected with the granite at a little distance from

1835.] Scientific Intelligence. 79

the mine, and has been introduced into the lias formation at the
period of the upheaving of the Pyrenean granite. The saccharoid
limestone of the Valley of Sue owes its texture to its position in
contact with the granite.

The limestone contains Pecten equivalvis ; Terebratulae and
Belemnites.

VI. — Geological position of the Campan Marble. By
M. Dufrenoy. (Ann. des Sciences, xxviii.)

This marble forms a subordinate bed in the transition formation of
the Pyrenees. It consists of nodules of limestone, agglutinated with
clay slate of a greenish or reddish colour, presenting an amygdaloid
appearance. The nodules are Nautili, of which the spiral form may
frequently be detected. Dufrenoy considers the formation contem-
poraneous with that of Plymouth. Near the village of Sirach, in
the Valley of Prades, besides Nautili, several fossils peculiar to the
transition formation appear. Prades is situated on granite. Over
the granite, clay-slate reposes containing felspar veins and red oxide
of iron. This slate is green, passes insensibly into a mixture of lime-
stone, and then into the marble. In the limestone which succeeds
are formed Orthoceratites, Terebratulae, and Encrinites, similar
to those of Dudley.

It is remarkable that the strata which contain the nautili are at a
distance from the granite, and that in proportion as we approach
this rock, the nodules loose their organized character. At a little
distance at Tuchan, slates resembling those of Sirach occur covered
by the coal formation, where impressions of vegetables appear abun-
dantly. The coal is worked at Segur and Quintillan.

VII. — Effect of Gases on Vegetation. By M. Mac aire.
(Ann. des Sciences Naturelles.)

M. Macaire introduced some plants of Euphorbia, Mercurialis,
Senecio, Sonchus &c. into vessels along with chloride of lime in
the morning. When evening arrived the plants had not sufFered,
and the odour of the chlorine was as strong as at first. Next morning
they were found withered, the smell of chlorine had disappeared,
and was replaced by a very disagreable acid odour. The same result
was obtained on repeating the experiment several times.

Nitric acid withered the plants during the night, but in the day
time merely rendered some of them brown coloured.

Sulphurretted hydrogen produced no alteration when light was
present, but destroyed them in the night, by the absorption of the gas.

Muriatic acid gas acted in a similar manner.

VIII.— Notices of the Natural History of Egypt in 1832.
By M. Roux. ( Ann. des Scien. Nat.)

The only species of Helix which he found was the irregularis, in
the vicinity of Alexandria. He discovered two new species of

80 Scientific Intelligence. [Jan.

Salicoques, in the Nile which he termed Palaemon Niloticu and
Pelias Niloticus.

Ml Mokatan, in the neighbourhood of Cairo, consists essentially of
a limestone with nummulites, affording fine specimens of a species
belonging to the genus Xantho. Egypt is well supplied with birds
of prey, and contains most of those found in France. M. Roux saw
a Fringilla approaching the Cisalpina of Temminck. In Fayoum
he noticed flocks of pelicans to the amount of thousands, which
produced a noise resembling the discharge of musketry when they
struck the water with their wings in attempting to rise. They
appear easily capable of being domesticated. Mr. Hey an English-
man, possessed one which used to fly to the marshes adjoining the
Nile for the purpose of procuring food, but returned regularly to
the canja of its master.

Immense flocks of Anas Cinereus, se^etum and albifrons, and
perhaps also erythropus, may be observed in the morning and even-
ing ; the egypticus is found principally in the rocks of the Arabian
chain. M. Roux found a new insect belonging to Aptera hexapodes
among the sands at Giseh, which he terms Necrophylus arenarius,
The birds embalmed were Neophron permopterus, a species oifalco.
(faucon crassarelle,) Sparvius palumbarius, Ibis fascinellus. At
Saccarah he never noticed Ibis sacer.

IX. — Summary of a Meteorological Register kept at Eccles*
Berwickshire. By the Rev. James Thomson.

Barometer. Thermometer.

December 1833 . . . 28*960 43°-6

January 1834. . . . 29*411 38°*5

February — -570 40°-l

March — -531 45°4

April —-765 46°-8

May —624 55°2

June —-526 60°-4

July —-586 60°-8

August ...... — -444 62°-2

September — -594 55°-0

October —-482 49°-9

November — -510 43°-5

Mean for 1834 29*500 50°- 11

" 1833 29-257

" 1832 .... . 29-523

Mean for three years . . . 29*426

* Eccles is situated in about 55° 40' N. L.

ERRATUM.— Page 44, line 21.— The quantity of oxide here given is what is
contained in 100 grains of the mineral.
Page 70 last line, for 880-6 read 80°'5.

RECORDS

OF

GENERAL SCIENCE

FEBRUARY, 1835.

Article I.

Biographical Account of Alexander Volta. By M. Arago.
( Abridged from the Ann. de Chimie, vol. liv.J

Amber it was remarked, as early as the times of Theophrastus
and Pliny, possesses the remarkable property of attracting
light bodies, such as feathers, after it has been smartly
rubbed. The name of the substance ( electron ) came to be
applied to this property, which it acquired by friction. For
a long period electricity was confined to narrow limits, but
to Volta was left the developement of the brilliant science
which has succeeded the discovery of the principle, for he
found electricity by the aid of peculiar apparatus every
where ; in combustion, in evaporation, in the simple ap-
proximation of dissimilar bodies ; and thus assigned to this
powerful agent an immense field among terrestrial pheno-
mena, which yields only to that of gravity.

Alexander Volta, one of the eight foreign associates of
the Academy of Sciences, son of Philip Volta, and Magdalene
de Conti Inzaghi, was born at Como, in the territory of
Milan, on the 14th February 1745. He was educated under
his father's eye, in the public school of his native city, and
from his talents and indefatigable application, speedily
surpassed his school-fellows. At ten years of age he com-

vol. I. G

82 Biographical Account of [Feb.

posed a Latin poem descriptive of the phenomena observed
by the most celebrated experimenters of the day, which has
never however been published, and afterwards he wrote
some verses on Saussure's ascent to the summit of Mont
Blanc.

At eighteen years of age he corresponded with Nollet,
upon some of the most delicate questions in physics.

When twenty- four, he broached the subject of the Leyden
phial in his first Memoir. This apparatus was discovered
in 1746. Its singular effects were sufficient to justify the
curiosity which it excited over all Europe ; but this excite-
ment was in a great measure increased by the foolish
exaggeration of Muschenbrbek, who on receiving a feeble
charge, was affected with such extraordinary fear, that he
exclaimed emphatically, that he would not undergo a
second shock for the finest kingdom in the universe. To
Franklin is due the honour of having explained the mode
of action of the Leyden phial.

The second Memoir of Volta appeared in the year 1771,
in which we find no idea of system. Observation is the
author's only guide in endeavouring to determine the
electricity of bodies, and in assigning the temperature,
colour, and elasticity, which produce variations of the pheno-
mena, and in studying the cause of the production of
electricity, whether by percussion, friction, or pressure.

In Italy these Memoirs produced a strong sensation, and
their author was elevated to the situation of Regent of the
Royal School of Como, and soon afterwards was made
professor of physics.

The missionaries at Pekin, in the year 1775, communi-
cated to the philosophers of Europe the important fact
which they had accidentally observed, that electricity shows
itself or disappears in certain bodies, when they are sepa-
rated, or in immediate contact. This fact originated the
interesting researches of iEpinus, Wilcke, Cigna, and
Beccaria. Volta also made it his particular study, and
drew from it his idea of the perpetual electrophorus, an
admirable instrument which, in the smallest size, forms a
source of the electric fluid.

To his memoir upon the electrophorus, succeeded in 1778
another very important work. It had been already observed

18:35.] Alexander Volta. 83

that a given body, whether empty or full, possesses the elec-
trical capacity, provided the surface remains constant. The
experiments of Volta, however, shewed that of two cylinders,
possessing the same surface, the longest receives the greatest
charge, so that an immense advantage is gained by substitut-
ing for the large conductors of common machines, a system
of very small cylinders, although on the whole, these do not
occupy a greater bulk. In combining for example, sixteen
wires of thin plated rods, each 1000 feet in length, according
to Volta a machine would be produced whose sparks would
kill the largest animal.

None of Volta's discoveries were fortuitous. All the
instruments with which he enriched science were fairly
planned out in his imagination before the artist was em-
ployed to construct them.

In 1776 and 1777, the professor of Como was occupied
with purely chemical subjects. At this time chemists
considered that inflammable gas was a product of coal and
salt mines only, but Volta proved that the putrifaction of
animal and vegetable substances is always accompanied
with the disengagement of inflammable gas, and that if we
stir the bottom of stagnant pools, the gas escapes, producing
all the appearances of ebullition. Thus, the carburetted
hydrogen of marshes was first discovered by Volta.

He ascribed burning mountains and formations to the
same cause; and in 1780, visiting Pietra Mala de Velleja,
he proved that the phenomenon so celebrated at that place
was owing, not to petroleum or naphtha, but to carburetted
hydrogen. The electric spark was used to set fire to certain
liquids, vapours, and gases, such as alcohol, the smoke of a
newly extinguished candle, and hydrogen, but all these expe-
riments were made in the open air. Volta was the first who
repeated them in close vessels, in 1777, and to him there-
fore, is to be ascribed the idea of the apparatus in which,
in 1781 , Cavendish synthetically formed water by combining
the two constituent gases by means of the electric spark.
\ Volta never abandoned a subject until he had considered
it in all its branches, uniting in a remarkable manner, the
unusual combination of an inventive genius, and the spirit
of application. Thus, in his researches upon inflammable
gas, he discovered the electrical gun and pistol, then the

g 2

84 Biographical Account of [Feb.

permanent hydrogen lamp, so well known in Germany,
which lights itself by the most ingenious application of the
electrophorus ; and lastly, the eudiometer, which is still an
indispensible instrument in the analysis of gases, and has
enabled us to ascertain, that notwithstanding the immense
consumption of oxygen by men, quadrupeds, and birds, in
the act of respiration, and its necessary support of combus-
tion, whether we examine atmospheric air in the scorch-
ing equitorial regions, over the immensity of the ocean, the
elevated plains of Asia or America, the snowy summits of
the Cordillera or Himmalays, the proportion of oxygen
remains constant. Humboldt, Gay Lussac, and others,
have investigated the accuracy of different eudiometers,
and have found that Volta's is by far the most accurate.
In connexion with this subject, although not in chrono-
logical order, may be mentioned the experiments which he
published in 1793, upon the dilatation of air.

This question had attracted the attention of philosophers,
the results of whose experiments were very discordant.
Volta discovered the cause of these differences and shewed,
that in experimenting in a vessel containing water, we
ought to find increasing dilatations ; that, if there is not in
the apparatus any moisture but what usually covers the
glass, the apparent dilatation of the air may be increasing
in the lower part of the thermometric scale, and decreasing
in the upper part ; he proved by delicate experiments, that
atmospheric air, if it is contained in a vessel perfectly dry,
dilates in proportion to its temperature, that is, the elasti-
city of a given volume of atmospheric air is proportional to
its temperature.

When we heat air taken at a lower temperature, contain-
ing always the same quantity of moisture, its elastic force
increases like that of dry air. Hence, Volta concluded that
the vapour of water and air, properly speaking, dilate in the
same way, which is now known to be correct. Our know-
ledge upon this subject is, by the labours of Gay Lussac
and Dalton, now complete. They made their experiments'
before those of the Italian philosopher were known either
in England or France.

We come now to the researches of Volta upon the elec-
tricity of the atmosphere; but before considering them, it

1835.] Alexander Volta. 85

is proper to attend to the knowledge which had been previ-
ously acquired in this department. Dr. Wall, who wrote
in 1708, offers the ingenious observation that the light and
crackling of electrified bodies appear to a certain extent, to
represent lightning and thunder.

Stephen Grey, in 1735, observed that in time it is probable
means will be found of concentrating great quantities of
electrical matter, and of increasing the power of an agent,
which appeared to him, if small things can be compared
with great, to be of the same nature as thunder and
lightning.

Nollet, in 1746, gave it as his opinion that thunder, in
the hands of nature, is electricity in the hands of natural
philosophers.

The first views of Franklin, like those of his predecessors,
were simple conjectures ; but the former did not rest satisfied
with conjecture; he proposed to bring it to the test of
experiment, by observing if a pointed metallic rod would
afford sparks, during a thunder storm, similar to those of
the electrical machine. Without wishing to tarnish the
glory of Franklin, it may be remarked that the proposed
experiment was unnecessary. For the soldiers of the Fifth
Roman Legion had already made it during the African war,
on the day when, as Caesar tells us, the iron of their javelins
appeared on fire ; and in Friol at the chateau of Duino, the
overseer did what Franklin desired, when conformably to
his orders, with the view of protecting the fruits on the
approach of a storm, he ascertained with an iron instru-
ment, if sparks could be obtained from a rod placed verti-
cally. On the 18th May 1752, D'alibard during a storm,
procured small sparks from a pointed piece of metal which
he had placed in his garden, which was a month previous
to the results obtained by Franklin with his kite.

The introduction of thunder rods was the consequence of
Franklin's discovery. It is curious to look into some of the
writings of that period. In one place you find travellers
braving the storms with sword in hand, in the attitude of
Ajax menacing the heavens; in another, the clergy, to
whom custom has interdicted the sword, regretting bitterly
that they were deprived of this precious talisman. Some
philosophers did not admit the utility of these instruments.

86 Biographical Account of [Feb.

They granted the identity of lightning and the electric fluid,
the experiment of Marly la Ville having decided the point ;
but the small number of sparks which proceeded from the
rod made them doubt the possibility of extricating the
immense quantity of matter contained in a cloud. Even
the dangerous experiments of Romas de Nerac did not
satisfy them ; but the melancholy death of Richman, on the
6th August 1753, by the electric fluid which was conducted
by the string of a kite which he was raising, convinced
them of the fact, and enabled them they conceived to
explain a passage in Pliny, where the naturalist relates that
Tullus Hostilius was killed by lightning for having been
irregular in the performance of ceremonies, in consequence
of his predecessor Numa causing thunder to descend from
heaven. Subsequently, disputes occurred with regard to
the propriety of using thunder-rods with sharp points or
with nobs.# Lemonnier, in 1752, discovered that electricity
existed in the atmosphere, not only during storms, but
when the sky was perfectly clear. He observed also, that
in clear weather it underwent regular variations of intensity ;
and Beccaria established the fact that in all seasons, at all
heights, and during all winds, the electricity in clear
weather is constantly positive or vitreous.

For a considerable period after the Leyden phial had
been discovered, the electrometer was not thought of. Darey
and Le Roy, in 1749, invented one, and in 1752 Nollet pro-
posed an instrument consisting of two threads, which, after
being electrified by the effect of repulsion, separated like
the legs of a pair of compasses.

Cavallo, in 1780, realized what Nollet had only projected.
His threads were of metal, and bore at their extremities
spheres formed of the pith of the elder. Volta substituted
for the pith dried straws. His letter to Lichtenberg in
1786, in which he established, by numerous experiments,
the properties of electrometers formed with straws, contains
a description of the method by which these instruments
may be compared ; of the intensity of the greatest charges,

* I have omitted in the text to mention the observation of M. Arago, that the
circumstance of George III. taking part with those who recommended rods with
nobs, against Franklin, who advocated the use of pointed conductors, is to be
considered an important incident in the history of the American Revolution. — Edit.

1835.] Alexander Volta. 87

and of certain combinations of the electrometer and con-
denser. This letter is well worthy the attention of young
philosophers.

In 1785Saussure increased the delicacy of the electrometer,
by the simple addition of a stalk, eight or nine decimetres
in length. And Volta in 1787, further added to its sensi-
bility, by adapting to the metallic addition of Saussure a
lighted candle, or even a match. He even suggested that,
from the excellent electrical conducting power of flame,
the best method of preventing the evil effects of thunder
storms, would be to make large fires in the midst of plains,
or on the summit of elevated places. His views have not
hitherto been subjected to the test of experiment. Perhaps
some light might be thrown on the subject by comparing
the meterological observations of those localities where
iron-works are established with the surrounding agricultural
districts. The learned endeavoured, not from a wish to
honour the dead, to show that his discovery had been anti-
cipated by the ancients, and considered that the fabulous
Greek fires were to be ascribed to this cause.

The hypothesis which had been formed that the electric
phenomena are attributable to two fluids, naturally con-
ducted to the investigation of the source from which they
emanate. A simple experiment tended to solve the question.
A vessel insulated where water was evaporating gave evident
proofs of negative electricity. •

It is not well known to whom the merit of this experiment
is to be ascribed. Volta in one of his memoirs says, that
he had thought of it in 1778, but that different circumstances
having prevented him from executing it, he only succeeded
at Paris in March 1780, in company with some members of
the Academy of Sciences. On the other hand, Lavoisier
and Laplace merely say that Volta wished to assist at their
experiment, and to be useful to them. The cause of this
difference in their statements is that Volta was present at
the first experiment, which did not succeed, but was absent
from the successful one. He, however, planned the means
of discovery and the actual experiment, and is entitled to
the credit of the success. According to him, when the
insulated metallic vessel in which water is evaporating
becomes electrical, the water, .in order to pass into the

88 Biographical Account of [Ffb .

gaseous state, imparts to the bodies which it touches, heat
and electricity. The electrical fluid is therefore an essential
part of the great masses of vapours which are daily formed
at the expense of seas, lakes, and rivers. These vapours
being condensed in the cold regions of the atmosphere, the
electricity would accumulate, unless rain, snow, and hail
enabled it to return to its proper source.

We arrive now at the important epoch when a new form
of electricity was discovered. If is curious that the im-
mortal invention of the galvanic pile owes its origin to a
slight rheumatism with which a lady of Bologna was
affected in 1790, and for which, a dish of frogs was pre-
scribed by her physician. Some of these animals, deprived
of their skins by the cook of Madame Galvani, lay on the
table, when accidentally, an electrical machine was dis-
charged. The muscles although they had not been touched
by the sparks, were strongly contracted. Galvani, in
varying his experiments upon this point, observed that
similar contractions may be produced by interposing one or
two plates of a metal between a muscle and nerve ; and,
following up his researches, he thought he had proved
that positive electricity had its seat in the nerves ; negative
electricity in the muscles. These views seduced the public ;
electricity now took the place of the nervous fluid, which
had long been a great favourite, although its existence no
one had attempted to demonstrate, and it was thought that
the physical agent had been at length obtained in an insu-
lated state, which carries to the sensorium the external
impressions; but alas! this romantic dream was dispelled
by the rigid experiments of Volta, for he proved that con-
tractions are produced by merely touching the muscle with
two metals, and affirmed that electricity was the active
agent in these contractions.

Although opposed on all hands, he continued stedfast
in his opinions ; and at present, when a splendid science
has been erected on the discovery of Galvani, his deductions
are found to be correct.

It wa3 in the beginning of the year 1800 that Volta .
constructed the pile, the most wonderful instrument which
human intelligence has ever created ; for to it we owe some
of the finest discoveries in chemical science ; and with it

1835.] Alexander Volta. 89

must the name of Volta be handed down to succeeding
generations.

Some of the biographers of Volta have accused him of
enfeebled intellect during the last thirty years of his life,
but this charge must be repelled, when we learn that he
wrote two ingenious memoirs, the one upon the phenomenon
of hail, and the other upon periodical storms, and the cold
accompanying them, sixteen or seventeen years after the
discovery of the pile.

The duties to which Volta had been bound almost from
his infancy, retained him in his native city till 1777, when
he left the picturesque banks of the lake of Como, and
passed into Switzerland. At Berne he visited Haller, who,
from the immoderate use of opium, was early sent to his
grave.

At Geneva he formed a warm friendship with the historian
of the Alps, who was well able to appreciate the value of
his discoveries. That was a great age when the traveller,
without losing sight of Jura, could visit Saussure, Haller,
Jean Jacques, and Voltaire. Volta after an absence of a
few weeks, returned into Italy by Aigue Belle, carrying
with him, for the benefit of his country, that precious root
whose proper cultivation renders famine impossible. He
wrote an account of his journey, which was long buried
in the archives of Lombardy, and was only published in
1827, by M. Antoine Reina of Milan, on his marriage, for
in Italy every one in his own sphere, at this happy period,
endeavours to confer some benefit on his countrymen. So
remarkable are human institutions, that the fate of one of
the greatest geniuses of which Italy can boast was at the
mercy of the Administrator-General of Lombardy. For-
tunately, Count Firmiali who occupied this station, was a
friend of letters. The school of Pavia became the object
of his attention. He then established a chair of physics,
and in 1779, conferred it upon Volta. There Volta taught
for many years numbers of young men who congregated
from all parts of the country, not indeed, the mere details
of science, which can be learned from books, but the
' philosophical history of the different discoveries, and those
minute facts which escape vulgar intellects.

The language of Volta was lucid without preparation,

90 Biographical Account of [Feb.

sometimes animated, but always impressed with modesty
and politeness. These qualities, when allied with merit of
the first order, always make a deep impression upon youth ;
but in Italy, where the imagination is easily raised, they
produced complete enthusiasm. Volta, like his country-
men, was a domestic person, and it is thought he never
visited Naples or Rome. Certain it is that he never stirred
from home except with scientific views. If in 1780 we find
him crossing the Appenines from Bologna to Florence, it
was for the purpose of investigating at Pietra Mala the
nature of the inflammable gas. If in 1782, accompanied by
the celebrated Scarpa, he visited the capitals of Germany,
Holland, England, and France, it was to form an acquaint-
ance with Lichtenberg, Van Marum, Priestly, Laplace,
and Lavoisier, and to enrich the Cabinet of Pavia with
philosophical instruments.

At the invitation of Bonaparte, Volta repaired to Paris
in 1801, where he repeated his experiments upon electricity,
before a numerous commission of the Institute. At the
suggestion of the First Consul, they voted him a gold
medal by acclamation ; and, as Bonaparte did nothing by
halves, on the same day Volta received from the funds of
the State, 2000 crowns to defray the expenses of his journey.
Bonaparte displayed his enthusiasm in the cause of this
branch of the science, by establishing a prize of £2500 in
favour of the individual who should make a discovery which
could be compared with those made by Franklin and Volta,
and further, conferred upon him the cross of the legion„of
honour and of the iron crown, named him Member of the
Italian Council, and elevated him to the dignity of Count
and Senator of the kingdom of Lombardy. Volta made no
figure as a politician, falling short in this respect of Newton,
who, during his parliamentary career, is said to have spoken
only once in the House of Commons, and the solitary oration
was to direct the doorkeeper to shut one of the windows
through which a draft of air was directed upon the member
who was addressing the house. Volta, however, never
uttered a word.

He married in 1794 Theresa Peregrini, by whom he had
three sons. Two of them have survived him; the other
died at eighteen, when the brightest hopes were entertained

1835.] Alexander Volta. 91

of his talents. This misfortune is the only one which our
philosopher may be said to have experienced during his
long career. His discoveries no doubt created envy ; but
if, as Franklin says, happiness like material bodies, is
made up of insensible elements, then was Volta happy.
His difference of opinion with Galvani was no doubt unfor-
tunate. Yet no Italian ever pronounced the name of Volta
without profound esteem and respect ; and, from Raveredo
to Messina, he was hailed by the title of our Volta. Besides
the distinctions conferred by Bonaparte, he was honoured
by the different Academies in Europe. But these dignities
never created pride in him. The little town of Como con-
tinued to be his favourite residence. The flattering and
repeated offers of Russia could not prevail upon him to
change the beautiful sky of Milan for the fogs of the Neva.
Ambition or the love of money had no influence on him.
The desire of study was the only passion he possessed,
which preserved him pure from worldly connexions. A
strong and quick intellect, extended and just ideas, and
sincerity, were the characteristics of the illustrious professor.

Volta was tall, possessing handsome and regular features,
like those of an ancient statue, with a large forehead, which
profound thinking had deeply furrowed His manners
retained some traces of the rural habits which he had
acquired in his youth. Many persons remember having
seen Volta when at Paris enter daily the bakers shops, and
eat in the street large loaves which he had purchased,
without supposing that any one would remark him. These
minute circumstances with regard to great characters are
interesting. Fontenelle has said of Newton that he had a
thick head of hair, and that he lost only one tooth.

When Volta resigned in 1819 his situation in the Univer-
sity of Tesino, he retired to Como, and gave up all his
connexions with the scientific world, scarcely admitting to
an interview any of the numerous travellers who were
attracted to the place by his renown. In 1823 an attack of
apoplexy threatened severe symptoms, which were overcome
,,by medicine. But in March 1827, the venerable old man
was seized with a fever, which in a few days exhausted his
remaining strength, and on the 5th of the month he expired,
without pain, aged eighty-two years and fifteen days. It is

92 Dr. Thomas Thomson on the [Feb.

remarkable that on the same day, and at the same hour,
France lost the immortal author of the Mecanique Celeste.

The remains of Volta were carried to the tomb with great
respect. The professors, the friends of science, the inha-
bitants of the town and neighbourhood, accompanied the
body of this wise philosopher, of this virtuous father, of
this charitable citizen, to its last home. The handsome
monument which has been raised to his memory, near the
picturesque village of Camnago, is a striking proof of the
sincerity of their sorrow.

The place of Foreign Associate, which was left vacant
by the death of Volta, was filled by Dr. Thomas Young.
Scientific bodies are fortunate, when in recruiting, they
can thus make genius' succeed to genius.

1 Article II.

Chemical Analysis of Thulite. By Thomas Thomson, M. D.,
F. R. S., L. and E. &c, Regius Professor of Chemistry
in the University of Glasgow.

This mineral has been known for about twelve years ;
but I am not aware that any mineralogical description of
it, or chemical analysis of it has been published, either in
this country or on the continent. I got a specimen of it
last summer, from Dr. Bondi of Dresden. It bears so
striking a resemblance to bisilicate of manganese, that I
had no doubt before examining it, that I would find its
constitution similar to the composition of that mineral.
The blow-pipe indicated merely a trace of manganese, so
small that it was not worth while to attempt to separate it.
But I found abundance of peroxide of cerium, which I did
not expect. It contains also lime, potash, and peroxide
of iron, all seemingly in combination with silica. It consti-
tutes, therefore, a new and not uninteresting species of
cerium minerals, hitherto rather few in number. I con-
ceive, therefore, that a short account of its mineralogical
characters, and of its chemical analysis, will be acceptable
to the mineralogists and chemists of this country.

The locality of Thulite is Souland in Tellemark, Norway.
The mass of my specimen is white granular quartz, through

1835.] Chemical Analysis of Thulite. 93

which the Thulite is disseminated. I am ignorant of the
name of the individual who discovered and named it.

The colour is a fine rose-red, streak greyish, while my
specimen exhibits the thulite only in grains of a greater or
smaller size. But Mr. Brooke informs us that he found it
to yield to mechanical division an oblique prism, with angles
of 87° 30' and 92° 30'. But he could perceive no distinct
cleavage transverse to the axis of this prism.

Lustre vitreous ; hardness about 6 ; but the grains
separate from each other so easily that it is not easy to
determine the hardness, translucent on the edges.

Specific gravity of my specimens 3*1055. Breithaupt
states it at 3*124. This is a sufficient proof that thulite
differs entirely from bisilicate of manganese, for the specific
gravity of that mineral is 3*538.

Before the blow-pipe it fuses with carbonate of soda into
a greenish white opaque globule. With borax it fuses into
a colourless transparent bead, with a quantity of uncombined
silica in the centre. If to this bead we add a little nitre,
and fuse rapidly, the bead assumes a violet colour, shewing
the presence of manganese.

The analysis of this mineral was conducted in the follow-
ing manner: —

1 . 20 grains, when ignited in a platinum crucible, lost 0*31
grains of its weight. This loss was considered as moisture.

2. I found it partially, but not completely, decomposed
by muriatic acid ; 20 grains of it were treated with muriatic
acid till every thing soluble was taken up. The portion
unacted on had still a red colour. It was fused with twice
its weight of anhydrous carbonate of soda; most of the iron
and a portion of the cerium were dissolved by the muriatic
acid. But the silica and lime remained undissolved. As
from a previous analysis I had ascertained the nature of the
constituents, the two solutions were mixed together, and
the ingredients were separated in the following way : —

3. The whole being evaporated to dryness, and the dry
matter digested in water, acidulated with muriatic acid,
the liquid was thrown on a weighed filter to collect the
silica. After washing, drying, and igniting the silica, its
weight was found to amount to 9*22 grains.

4. The liquid thus freed from silica was rendered as

94 Dr. Thomas Thomson on the [Feb.

neutral as possible, and then digested with benzoic acid for
about half an hour. The whole was then passed through a
weighed filter. The liquid that passed through the filter
was colourless ; the iron in the state of benzoate was retained
on the filter. Benzoic acid was used instead of benzoate of
ammonia, because I knew from previous experiments that
benzoate of ammonia throws down cerium as well as iron,
which is not the case with benzoic acid. The benzoate of
iron left on the filter was washed with a solution of sal-
ammoniac till every thing soluble was taken up. Had I
washed it with water, as it contained an excess of acid, the
greater part of the benzoate of iron would have re-dissolved.
The benzoate of iron being dried and ignited left 1*09 grains
peroxide of iron.

5. The colourless liquid thus freed from iron, was preci-
pitated by ammonia, and the precipitate collected upon a
weighed filter. It was a white transparent jelly, which
took a very long time to wash it properly ; but it gradually
acquired colour by exposure to the air ; and after being
dried and ignited in an open vessel it was red. It was
peroxide of cerium, and weighed 5*19 grains = 4*813 grains
of protoxide of cerium.

6. The liquid thus freed from cerium was precipitated
hot by oxalate of ammonia, and the precipitate was collected
on a weighed filter, washed, dried, and ignited; it amounted
to 4*48 grains, and was carbonate of lime = 2*5 grains
lime.

7. Nothing else could be found in the liquid when treated
with carbonate of ammonia.

The constituents thus found are

Moisture 0-31 or 1-55

Silica 9-22 „ 46-10

Peroxide of iron - - - - 1*09 ,, 5*45

Protoxide of cerium - - - 5*19 ,, 25*95

Lime 2*50 „ 12*50

18*31 91*55

The loss of 8*45 per cent, rendered it probable that the
mineral contained an alkali. To determine this point, 28
grains of it in fine powder, were intimately mixed with 50
grains of litharge and 25 grains of nitrate of lead, and fused

1835.] Chemical Analysis of Thulite. 95

for ten minutes in a covered platinum crucible. The glass
was dissolved in nitric acid, and the silica separated in the
usual way. The lead was then thrown down by sulphuric
acid, and the last portions of it by sulphuretted hydrogen
gas. The oxides of cerium, of iron, and the lime, were
then thrown down by carbonate of ammonia. The residual
liquid was evaporated to dryness, and the ammoniacal
salts driven off by heat, a salt remained, which after solu-
tion, evaporation, and ignition, was found to weigh 6*87
grains, but it was impure. After some attempts to purify
it I mixed it with chloride of platinum, (after converting it
into chloride,) and alcohol, and evaporated to dryness. The
dry yellow residue was digested in common spirits, and after
every thing soluble was taken up, I dried the potash
chloride of platinum, and exposed it to a very strong red
heat. By this means the platinum was reduced to the
metallic state. It was weighed, and from the amount of
weight, that of the potash chloride of platinum was deter-
mined. The quantity of potash indicated was almost exactly
2 grains, which amounts to 8 per cent. Hence, the consti-
tuents of thulite are

atoms.

Silica 46-10 „ 23-05

Peroxide of cerium - - 25-95 ,, 3*7

Lime 12-50 „ 357

Potash 8-00 „ 1-33

Peroxide of iron - - - 5*45 ,, 1*1
Moisture ------ 1-55 „ 1-38

99-55

The atoms of silica amount to 23*05, while those of all
the bases are 9-7. So that if we consider the mineral as
composed of bisilicates, there is an excess of 3*65 atoms.
This excess however is easily accounted for. The thulite
analyzed was interspersed with numerous grains of silica,
varying in size from that of a pea to an almost microscopic
globule. Though I was at the utmost pains to exclude
these grains from the portion subjected to analysis, and
carefully picked out all the pieces of thulite, which appeared
free from silica when viewed through a microscope, yet, in
consequence of the extreme minuteness of the silica, it was
impossible to exclude the whole. Hence the reason of the

96 Dr. Thomas Thomson on the [Feb.

excess of silica, which I believe to be only apparent. The
constitution of thulite may be stated as follows : —

3 atoms bisilicate of cerium.
3 atoms bisilicate of lime,
lj atom bisilicate of potash.
1 atom bisilicate of iron.

Whether the water be an essential constituent or not is
not easily determined. Probably it is only mechanically
lodged in the pores of the mineral. The constituents of
thulite may be represented by the following formula:—

3 Cer. SH3CSH 1J K S2 + /S2
Whether all these bisilicates be essential to the mineral
can only be determined by the analysis of purer specimens
than I possessed. Were the bisilicate of cerium the only
essential ingredient, thulite would differ from cerite by
containing twice as much silica. Cerite is a simple silicate
of cerium, while the cerium in thulite is in the state of
bisilicate.

Mr. Richardson analyzed in my laboratory cyprine which
accompanies thulite. Its specific gravity is 3*2278, and its
constituents,

atoms.

Silica 38-80 „ 19-4

Alumina 20-40 „ 9*07

Lime 32-00 „ 9-14

Protoxide of iron - - - 8*35 „ 1*8

99-55
It is obviously a garnet, and analogous to grossularite in
its composition. No trace of copper could be detected in
cyprine.

Article III.

Analysis of Arden Limestone. By Thomas Thomson, M. LT.
F. R. S., L. and E., &c. Regius Professor of Chemistry in
the University of Glasgow.

Arden limestone is found about six miles south-west from
Glasgow, and is well known and highly valued, because it
furnishes a lime which sets readily under water.

1835.J Analysis of Arden Limestone. 97

It is a compact opaque limestone, with a grey colour and
splintery fracture. Its streak is white, and its specific
gravity 2*698.

1. 50*33 grains of this limestone were dissolved in nitric
acid. The loss was 21*5 grains, which was chiefly car-
bonic acid.

2. The undissolved matter weighed 7*89 grains. It was
fused with carbonate of soda, and analyzed in the usual way,
and was found to consist of

Silica - - - 6-33
Alumina - - 1*56

7-89

3. The nitric acid solution was evaporated to dryness, the
residue was re-dissolved in water, and thrown down by
caustic ammonia. A red matter fell, weighing, after wash-
ing and ignition, 3 grains, and was peroxide of iron.

4. The lime was precipitated by carbonate of ammonia.
The carbonate being collected, washed and dried, and
heated to incipient redness, weighed 39*4 grains.

Hence, the constituents are

Carbonate of lime - - -
Peroxide of iron - - - -

Silica

Alumina

52-29 „ 99-90
When Arden lime, in the state of quicklime is dissolved in
muriatic acid, and the solution concentrated, it gelatinizes ;
a sufficient proof that the silica, during the burning of the
limestone, had combined with lime. To this silicate of lime
probably is owing the property which the lime has of setting
under water.

39-4 „

78-28

30 „

5-96

6-33 „

12-57

1-56 „

309

Article V.
Notice of some Recent Improvements in Science.
By the Editor.
One of the most important objects in establishing the
present Journal being to afford information in reference to
the progress of science abroad* I intend in the following
article, which will be repeated from time to time according

VOL. I. H

98 Notice of some Recent [Feb.

to the supply of materials, to throw together in a connected
form an account of some important improvements which
have recently been made in several branches of physical
science. The labour necessary in preparing such articles
as those individuals must be aware who have engaged in
similar avocations, is so considerable, that I trust to the
reader's indulgence in respect to any errors or omissions
into which I may have inadvertently fallen.

I. ACOUSTICS.

It has been recently observed by M. Breschet, that in many
of the chondropterygious fishes, as the skate, torpedo, &c,
there are open ducts, leading out externally, by which a
communication is established between the centre and the
membranous cavities of the labyrinth, while in many of the
osseous fishes, especially the cyprini or minnow tribe, and
the clupeae or herring tribe, &c, an opening exists between
the swimming bladder and the labyrinth. He has likewise
detected in the sacs of the labyrinth in man and vertebrated
animals, concretions which he terms otolites and otoconies.
(Ann. de Chim.9 lvi.J. M. Cagniard Letour has obtained
some curious results from his experiments on the sonorous
vibration of liquids, and has attempted to explain the use
of the concretions observed by Breschet. In employing a
glass tube one metre in length, closed at the bottom, and
filled with water, he found that when rubbed with a moist
cloth, a sound was produced resulting principally from the
longitudinal vibration of the column of water, yielding 790
vibrations in a second. A syphon, open at both ends and
filled with water, under the same circumstances, afforded
an acute sound. Hence, we can account for fishes hearing
in cases where their auditory organs contained no gaseous
matter. He tried the effect of vibrations upon other liquids.
Several substances more dense than water afforded more
acute, others, more grave sounds than that liquid.

Among the first are carbonate of potash at 71°, and muriate
of lime at 87°. Among the second, sulphuric acid at 150° ;
sulphuret of carbon and mercury. The same observation
holds with liquids possessing an inferior density to water.
He concludes, 1. That the liquids in human ears are con-
tained partly in species of tubes. 2. That these tubes or

1835.] Improvements in Science. 99

canals are osseous. 3. That the semicircular canals have a
curviture answering to that of the syphon. The ound
appears to be increased by introducing a solid in contact
with the water ; for, with a water hammer containing several
small rounded stones, the globular vibration of the liquid
took place without requiring to have any impulse commu-
nicated to it, as with the common hydraulic hammer.
Hence, he conceives that the concretions in the labyrinth
may facilitate the globular vibrations of the liquid in which
these bodies are suspended. Latour and Breschet are both
engaged in the further prosecution of this interesting sub-
ject. The latter is investigating the functions of the
semicircular canals in the slug.

II. ELECTRICITY.

M. Peltier # has obtained some important results from
his experiments on electric currents. He finds, 1. That
every electric current, whatever be its intensity, elevates
the temperature of homogeneous conductors. 2. That the
temperature is equal over the whole length of the wire,
with the exception of the extremities, where it increases or
diminishes according as the bodies to which the conducting
wires are attached are good or bad conductors. Thus, a
zinc wire between copper and iron wires of the same diameter
affords with the same current different temperatures at each
of the extremities.

3. Whatever be the length of a conductor the elevation
of temperature is the same under the same current, even
when the extremity of the conductor is plunged into a cold
liquid. In order to obtain the same quantity with a more
imperfect conductor, it is necessary to increase the energy
of the electrical source. If a complete current of 20° is
procured, the elevation of temperature will be 10° over the
whole length of the wire. Hence, it is the quantity of
electricity completing the circuit which determines the
elevation of temperature, and not the quantity detained.
With a current of 15°, and a wire of 0-8 diameter, the
temperature of the latter was 2°*4 ; with a current of 30° it
was 7°, that is in the proportion of 2 to 3, or with a double

* Ann. de Chim. lvi. 371.
H2

100 Notice of some Recent [Feb.

current or half section of the conducting wire the tempera-
ture is trebled.

4. When wires of different conducting powers were alter-
nated and employed to convey the electric current, he found
that when the negative current passed from a good into a
worse conductor, the greatest elevation of temperature
occurred, as from copper to iron, lead, or tin. The con-
trary took place with the positive current. When the
negative current passed from the zinc to the iron, the
temperature was 30°, but in the case of the positive current
the elevation was only 13°.

It is remarkable that the temperature is higher when
there is a solution of continuity. Thus, when two copper
wires were brought in contact with two plates of bismuth,
an elevation of temperature was exhibited, but disappeared
on soldering the metals.

Professor Marianini,# who is actively engaged in philan-
thropise endeavours to render electricity beneficial to the
cure of the diseases of his fellow creatures, has inferred,
from numerous experiments upon frogs, that when their
organs of motion are subjected to the influence of an electric
current, the electricity accumulates, until by its tendency
to flow back, it opposes the current which contributes the
new supply, so as to render the action of no effect, or to
excite much more feeble contractions than at the commence-
ment of the experiment, and that the accumulated electri-
city gives rise to a movement in the opposite direction to
that proceeding from the electrometer, when the circle is
interrupted, and hence, a contraction is induced. A frog
was electrified for five hours, the circle was interrupted,
and contractions were excited dictinctly under the action of
the returning current.

Upon these principles Marianini was induced to try the
effect of galvanism upon a patient affected with palsy, after
the failure of other remedies, and having succeeded in pro-
ducing a cure, he applied it in several cases with equal
benefit. (Ann. de Chim. liv. 366.)

Into one of these cases I consider it proper to enter par-
ticularly. The Countess M. Fenerazoli Sandi, aged 23 years,
on the 5th of May 1827, in crossing the room fell on the

* Ann. de Chim. lvi. 387.

1835.] Improvements in Science. 101

floor, and in endeavouring to rise, perceived that she had
lost the use of her legs, and that all sensation had disap-
peared in that part of her body. Marianini was called in on
the 25th of June, after several able physicians had failed in
doing her any good. He began the treatment with a voltaic
pile, composed of 58 plates of copper, and as many of zinc.
Each pair was separated from the succeeding by a piece
of cloth immersed in salt water. A slip of lead leading
from the positive pole surrounded the upper part of the
limb, and a similar slip, leading from the negative pole,
was connected with a plate of tin placed between the instep
and the toes when a shock was to be given. 150 shocks
were first given to one of the limbs, and then an equal
number to the other, then to both simultaneously 300
shocks. Between each shock an interval of two seconds
was observed, and a rest for three minutes after 40 or 50
shocks. Sometimes the electric fluid was communicated
for the sake of variety, in a current, in a circuit, or by a
needle point, which communicated a pricking pain to the
patient. This treatment was continued for an hour, and
was,repeated on the 26th, 27th, and 28th of June. On the
29th the number of plates was increased to 75. The sensa-
tion experienced was so disagreeable that a wet towel was
wrapped round the limb. This lasted till the end of July.
He substituted an apparatus with a circuit of 100 vessels.
(couronnes de cent tasses.) The net superficies of the plates
was three square centimetres, and the liquid conductor was
sea water.

The number of shocks during the day was 800. Until
the 6th of July the Countess felt no signs of improvement,
that is 12 days after having commenced the treatment. On
the 9th, she could perceive, by touching it, that her foot
was in contact with a moist body. On the 13th, the elec-
trification by puncture caused great pain, although only
made with five pair of plates. On the 15th, the patient
could put her foot to the ground, but with fatigue. On the
22d she was electrified for the last time, and walked without
being fatigued.

Marianini reports the cases of six other persons of various
ages whom he had treated in a similar manner successfully.
Some of these had previously been bled with leeches, and their
spines stimulated by sinapisms. It must be added, however,

102

Notice of some Recent

[Feb.

that Marianini was not successful in any other cases, although
we are not informed how many patients were subjected to
the same method of cure. Let it be borne in mind, how-
ever, that if by the application of the electric influence,
even five out of a thousand of our fellow creatures can be
restored to health, from helplessness and misery, the physi-
cian is not justified in withholding the. assistance of such a
powerful agent.

M. Matteuci# in examining the pneumogastric nerves,
could observe no current in them. He concludes that some
foreign agency was interposed when any developement was
exhibited, and that although, in all probability, the secre-
tions depend upon the presence of opposite electrical states
in the hearing organs, no means have yet been devised for
appreciating their existence.

III. MAGNETISM.

Declination of the Magnetic Needle. — The mean oscillation
or difference between the easterly position of the magnet
in the morning, and its western direction in the afternoon,
at Frieberg, is exhibited in the following table, according
to H. W. Dove. (Poggen. Ann. xxxi.)

March . .

11'

12"-8

May . . .

12

41-6

June .

12

58-8

August .

12

21-2

September .

11

25-8

November .

8

37-8

December .

3

49-8

The mean oscillation for March, June, September, and
December, is 9' 51''-8. The regular increase from the cold
to the warm months is very distinct.

The removal of the extreme of the magnetic meridian
and its position, is as follows :

March . .
May . . .
June . . .
August .
September
November
December

A. M.

EASTERLY.

A

M.

WESTERLY.

8h 20'

4' 44"-6

lh

20'

6' 28-2

8 20

4 30-7

1

20

8 10-9

7 20

5 333

1

40

7 26-5

7

4 43-4

1

20

7 37-8

7 20

2 48-8

1

8 37

8 20

1 36-6

1

40

7 1-2

7

8-7

1

3 41-1

* Ann. de China, lvi. 439.

1 835 . ] Improvements in Science . 1 03

The westerly deviation is therefore greater than the
easterly.

In the following table the time is exhibited during which
the needle remains to the west and east of the magnetic
meridian : —

WESTERLY. EASTERLY.

March . . 10h 20' - 13h 40'

May ... 10 — - 14 —

June ... 10 — - 14 — »

August . . 8 — - 16 —

September . 8 20 - 15 40

November . 8 — - 16 —

December .13 — - 11 —

The inclination of the needle near Freiberg is stated by
Humboldt to be at 250 metres (273*41 yds.) under the
surface, 67° 35'*5, and on the surface, 67° 32'*99.

Reich (Pogg. xxxi.) gives the result of three years, not
the mean however, of the monthly summary, but of the
whole year : —
1831. 67°24'-80. | 1832. 67° 22'-65. | 1833. 67° 20'- 15.

Lohrmann ascertained the inclination for Dresden to be
67° 26'*34. The observations in these instances were made
with Gambey's modification of the magnet for measuring
the inclination.

The declination of the needle at Sitka, on the NW coast
of America, according to Erman, is 28° 19' E, the inclina-
tion 75° 43'.

IV. PNEUMATICS.

Mean Height of the Barometer at the Sea. — This is a sub-
ject which has latterly attracted much attention. Professor
Schouw of Copenhagen, more especially (Poggendorff's
Ann.) has collected numerous good observations, and has
drawn some remarkable inferences, which are strikingly
corroborated by the following tables, extracted from my
own observations with an excellent instrument made by
Cary. They illustrate an interesting law by which the
barometer is depressed as we approach the equator.

The numbers are corrected for temperature by the
attached thermometer. The observations were made at
10. a. m.

104

Notice of some Recent

[Feb.

N. Atlantic— N.E. trade.

S. Atlantic— S.E. trade

N. I..

BAR.

8. L. BAR.

35° 36'

-

30-329

22 19 - 30-063

34 4

-

30-389

28 - 30-094

31 1

-

30-212

29 40 - 30-152

27 24

30-024

32 16 - 30-121

24 45

-

29-974

33 30 - 30-158

20 52

-

29-910

17 29

-

29-868

8. Indian Ocean. — S.E. trade.

6 21

-

29-882

S. L. BAR.

31° 55' - 30-233

s.

Atlantic— S.E. trade.

27 48 - 30-123

S. I..

BAR.

19 28 - 29-934

5° 32'

-

29-853

13 26 - 29-856

8

-

29-821

9 43 - 29-843

13 7

-

29-946

From these tables it is obvious that the height of the
barometric column is increased as we recede from the equator,
at which part of the earth's surface it appears to assume a sta-
tionary elevation, which may be taken as a close approxima-
tion to the mean density at the level of the sea. The standard
barometric pressure for Britain has usually been considered
to be 29*820, while the mean of the lowest heights in the
observations previously stated is equivalent to 29*844.

The mean of eight observations at the Cape of Good Hope
gives for the height of the barometer 29'861 inches.

With regard to the Atlantic Ocean, Schouw sums up his
deductions under five heads : —

1. There is a zone between 0° and 15° possessing an
elevated temperature where the rains are periodic, the
annual mean of the barometer lying between 337'" and 338".

2. A zone between 15° and 30°, where steady winds pre-
serve the air dry, where rains seldom fall, the barometer
being 338 to 339.

3. In the third zone, between 30° and 45°, the dry winds
are interrupted, especially in winter, by the S.E. wind, or
returning trade breeze, which takes up the moist and hot
air of the torrid zone, and produces aqueous precipitations.
The mean barometric pressure is between 339" and 337'".

4. The fourth zone is comprised between 45° and the
polar circle. It receives during the whole year, and espe-
cially in summer, the returning trade wind, which, in
consequence of its meeting with colder winds, occasions
frequent rains. The barometer is 337" to 333*5'".

5. Beyond the polar circle, in the fifth zone, the mean
barometric pressure increases.

1835.] Improvements in Science. 105

Mean Temperature of the Air. — The mean temperature of
different places on the earth's surface, is a point of much
importance, in reference particularly to its steadiness, during
a given period. Because by such data, we are enabled to
determine whether the globe possesses a calorific focus from
which heat is continually emanating, or whether, according
to some philosophers, it is gradually throwing off the heat,
which its whole mass was originally possessed of.

Laplace has shewn in his observations on the ancient
eclipses, that the temperature of the earth has not varied
for 2500 years, the^o of a degree.

Fourier as has already been mentioned {Records of
General Science, vol. i. p. 70,) proved that the cooling
cannot have exceeded the ~^ of a degree during a century.
And M. Arago demonstrated that during 2001 years, the
maxima of cold have not increased.

Libri {Ann. de Chim. lii. 395,) has drawn the following
conclusions from his analysis of different theories. 1 . In
the interior of the earth, the temperature of the strata,
increases or diminishes with the depth. 2. From direct
observations, the calculation of eclipses, and the mathe-
matical theory of heat, it appears to be demonstrated, that
the mean temperature of the globe has not varied during
the historic period. 3. Future observations may perhaps
enable us to ascertain if the moon has attained a state of
calorific equilibrium, or if its mean temperature varies.
4. In a given time the cooling of each stratum in the earth
being proportional to the quantity of heat, the cooling will
be more rapid in the hottest strata towards the centre of
the earth. Hence, in order to study the future variations
of the mean temperature of the earth, it will be necessary
to make experiments with thermometers, deposited at very
considerable depths in the earth.

It is obvious, however, that we are extremely limited in
our means of determining temperatures at great depths,
the most distant point from the surface which has yet
been attained in this country (250 fathoms,) being a most
insignificant fraction of the earth's radius.

There are several methods of ascertaining the mean
temperature of terrestrial localities, which have been
employed with considerable success. Registers of the
thermometer have been kept during the several days of the

106 Notice of some Recent [Feb.

year, and a mean struck of the whole observations. The
altitude of a mercurial column has been noted, and the
density of the air has thus been applied to discover the
temperature, by means of calculations which are sufficiently
well known. The temperature of deep springs has been
considered as an index of the mean temperature of the
locality in which such aqueous sources occur.

These methods, however, do not apply equally well to
small as to great elevations above the level of the ocean.

The depth at which an invariable temperature is met
with, varies in different situations. M. Arago found that
at 25 feet, (26*6 English feet,) below the surface of the
earth, the thermometer was not steady, and did not indi-
cate a constant mean temperature. This may be ascribed
to the influence of the variable atmospheric temperature.
Taking advantage of this inference, Boussingault conceives
that in climates where the temperature is tolerable equable,
the earth can be affected to but a very slight extent by
slight alternations of heat, as happens in equinoctial situa-
tions, {Ann. de Chim. liii. 225.) In 1830, during his resi-
dence at Vega de Zupia, he instituted a set of experiments
with the view of settling this point, and came to the con-
clusion, that in less than an hour, a traveller may ascertain
the mean temperature of any place between the tropics,
whatever its elevation above the level of the sea may be.
To prevent the effect of atmospheric influence, he experi-
mented under cover of a cottage or in the shade. The ther-
mometer was introduced into a hole, which was deep enough
to allow the bulb to be a foot below the surface, the hole was
then closed up by a bit of paper or other convenient sub-
stance. The temperature of Zupia was thus found to be
between 21°3 (70°3 F) and 21°5 (70°7 F,) which it must be
admitted is a close approximation, considering that the
observations amounted in number to twenty. At Marmato
the thermometer placed 1 foot below the surface, 1426
metres above the sea, ranged between 70o,3 and 70°7. In
the Valle de Cauca, 1050 metres above the sea, the range
of seven observations was 23°6 (74°4) and 23°8 (74°8.)

At Purace, 2651 metres of elevation, the thermometer
placed in similar circumstances stood at 13°1 steadily,
during six observations on two separate (lays. At Quito,
with an elevation of 2914 metres, the mean temperature

1835.] Improvements in Science. 107

according to the determination of Colonel Hall and M.
Salaza, during the whole year is 150,5 (59°9 F,) which
corresponds exactly with the results of Selaza, obtained by
placing the thermometer 1 foot under the surface. Boussin-
gault from these, and a few additional instances concludes,
that at least, between the 11° N. L., and 5° S. L., this
method of ascertaining the mean temperature holds good.

The mean temperature of the shores in the neighbour-
hood of the equator, has been a subject of discussion.
Humboldt fixed upon 27°5 (81°5 F.) Kirwan 29° (84°2.)
Brewster 28°2 (82°7.) Atkinson 29°2 (84°5,) as the tem-
perature of the equator. Hall and Boussingault again,
have found the temperature of the torrid zone to vary
between 26° (78°8 F) and 28°-5 (83°3 F.) I consider these
facts too important to be overlooked, and am happy in
being able to communicate to travellers such a simple,
and at the same time, so apparently correct a method of
ascertaining the mean temperature of intertropical places.
In connexion with this subject we may consider the

Temperature of Springs. (Pogg. Ann. xxxi. 365.) — Arago
remarked that the increase of the temperature of the earth
might be estimated by the depth of springs. Spasky
considers that the value of this increase may be deter-
mined with accuracy. From his observations on the springs
of Vienna he has drawn this equation,

T = A + ax
in which T is the observed temperature, A the (unknown)
temperature on the surface, a the depth, and x the increase
of temperature for 1 foot in depth. As the value of each
observation depends on the quantity of water delivered by
each well in 24 hours, each equation must be multiplied
with this quantity of water. The general expression there-
fore is mT = m A + m a x
where m represents the quantity of water in 24 hours.

For Vienna Spasky gives

A = 8-0311.
x = 0*0117716.
Mean error of A 008601.
Mean error of x 0*00065.

Mean temperature of the atmosphere 8° 2 R. The value
of a; being found, we obtain 85 feet, or less than 27 metres
for increase in the depth for each degree of Reaumur.

108

Notice of some Recent

[Feb.

V. CHEMISTRY.

Table of the specific heat of bodies.
Avogadro has recently made experiments upon this interesting
subject. The following table contains the results of these trials,
with the numbers affixed by other experimenters. #

Carbon ....
Protoxide of lead .
Red oxide of mercury
Protoxide of tin . .
Deutoxide of copper
Oxide of zinc . •

Anhydrous lime . •

Peroxide of iron. .

Red oxide of lead . .
White oxide of arsenic

Alumina, anhydrous .
Deutoxide of tin . . .
Peroxide of manganese
Quartz ......

Sulphuret of iron . . .
Sulphuret of lead . . .

Cinnabar

Yellow sulphuret of arsenic
Chloride of sodium . . .
Chloride of potassium . .
Chloride of lime ....
Deutochloride of mercury .

Protochloride

Red oxide of iron (hydrous)
Alumina (hydrous) . . .
Lime (hydrous) ....
Potash (hydrous) . . .

Carbonate of lime . . .

Carbonate of potash (anhydrous) . .
Carbonate of soda (anhydrous) . . .
Sulphate of lime (anhydrous) . . .

Sulphate of potash

Sulphate of soda (anhydrous) . . .
Sulphated protoxide of iron (anhydrous)
Sulphate of copper (anhydrous) . . .
Sulphate of zinc (anhydrous) . . .

Nitrate of potash

Nitrate of soda

Sulphate of lime (hydrous) ....

Avoprado

0-257
0-050
0-050
0-094
0-146
0-141

0-179

0-213

0*072
0-141

0-200
0-111
0-191
0-179
0-135
0-046
0-048
0-105
0-221
0-184
0-194
0-069
0-041
0-188
0-420
0-300
0-358

0-203

0-237
0-306
0-190
0-169
0-263
0-145
0-180
0-213
0-269
0-240
0-302

0*25 Crawford

0'049 Gadolin

0*50l Lavoisier and Laplace

0*096 Crawford

0*227 Crawford

0-137 Do.
S 0-223 Crawfoid
£ 0*21 7 Lav. and Laplace

0-167 Gadolin
r 0*068 Crawford and Kirwan
y 0-059 Gadolin
C 0-062 Lavoisier and Laplace

0-185 Gadolin

0-096 Crawford

0-195 Crawford (agate)

0-226

S 0-256 Crawford
* 0-207 Gadolin

Ann. de Chim. \v. 92.

1835.] Improvements in Science. 109

Atmospheric Air. — According to Berthollet, by the usual
phosphorus eudiometer, the remaining azote is increased
by the phosphorus vapour 4^ of its volume. To satisfy him-
self upon this point, Brunner passed a quantity of atmos-
pherical air from a gas holder, first through mercury and
chloride of lime, and then through red hot iron filings.
The gas thus freed from oxygen was placed over mercury,
the temperature and pressure being noted. A stick of dry
phosphorus was next allowed to remain for some time in
the gas, but produced no change in its volume. Some-
times, after standing many days, a slight dimunition took
place, but never amounting to 1 per cent., which was
ascribed to the admission of a small portion of oxygen.

Tralles, from theoretical views, calculated that the quan-
tity of oxygen in atmospherical air diminishes with the
height, and that at the surface of the sea, air contains

21*00 per cent.
1000 feet above the sea 20*90
8000 Do. - - 20*22

Saussure found the quantity less upon the hills than in
the vallies, (1*25 less) by means of Priestley's eudiometer.
Berger, with sulphuret of potassium, phosphorus, and
nitrous oxide, estimated the proportion at between 20 and 21
per cent.

Configliachi observed that with phosphorus the propor-
tion of oxygen was smaller below 50° than above 64£°.

The mean of 14 experiments by Brunner gives for the
proportion of oxygen in common air, determined by means
of phosphorus, 20*915 per cent.

The smallest quantity obtained was 20*75, the temperature
of the residual azote being 50° F, and the pressure 555*9
millimetres, and the greatest result was 21*11 when the
thermometer was 53f° F, and the barometer at 556.0 mill.
Both experiments were made about 7 a. m. (Pogg. xxxi. 1.)

Compounds of Carbon and Hydrogen. — Dumas and Boullay
have endeavoured to prove, by numerous analyses, that,
1. A compound of carbon and hydrogen acts as a base,
analogous to ammonia; 2. That alcohol and ether are
hydrates of this body ; 3. That carbohydrogen forms with
hydracids, anhydrous compound ethers; and 4. That the
same body with oxygenacids forms compound ethers con-
taining an atom of water.

110 Notice of some Recent [Feb.

Dumas conceives that alcohol contains hydrogen united to
water, and hydrogen united to carbon. Following out these
theoretical considerations, he has examined the product of
the distillation of alcohol with chloride of lime in solution
which he terms chloroforme. It consits of

Carbon 10'24

Hydrogen- - - 0*83
Chlorine - - - 88*93

100-00

The formula for this compound is obviously 2 C + H +
3Ch.

Bromoforme is prepared by treating bromide of lime
with alcohol, or pyro-acetic-spirit. It consists of

Carbon 5*44

Hydrogen 0*47

Bromine 94*09

100-00

and its formula is3C + H + 3B.

Iodoforme is formed in a similar manner, and contains

Carbon 3-20

Hydrogen 0-33

Iodine 96-47

100-00

corresponding nearly with 2 C + H + 3 I.

Chloral has its composition expressed according to Dumas,
by the formula, 4C + H + 0 + 3Ch.

Mercaptan. (Ann. de Chim. lvi. 113.J — When sulphovi-
nate of barytes is distilled with a solution of sulphuret of
barium, an ether passes over which swims on water, and
may be freed from sulphuretted hydrogen attached to it
by agitation in water, and separated from water by
chloride of lime. Thus purified, it is colourless, smells
like assafoetida, and burns readily. By distillation it
is separated into a more volatile portion, termed by Zeise,
mercaptan, an extraordinary appellation, from its affinity
for mercury, (corpus mercurium captans,J and into a more
fixed substance called thealic ether.

Mercaptan, when obtained pure from the mercaptide of
mercury, is colourless, with a smell of assafoetida. Sp. gr.

1835.] Improvements in Science. Ill

0-842. Boiling point 62° (143° F.) Very soluble in alcohol
and ether; acts with violence on deutoxide of mercury,
forming a compound of Hg + 2 Su + 4 Su + 4 C + 10 H.
So that the composition of mercaptan is4C + 10 H + 2Su.
The mercaptide of mercury melts at 86° C, resembles fused
chlorale of potash, it is decomposed at 175° C ; it is insoluble
in water. Mercaptide of gold consists of 2 Au + 4 C + 10
H + 2 Su, is an amorphous mass without colour, and is
not decomposed at 220°. Mercaptide of platinum resembles
that of mercury in composition. Mercaptides of potassium
and sodium are alkaline.

Zeise conceives the state of the combination of the ele-
ments of mercaptan may be represented by (4 C + 10
H + S) + (2H +S.) Liebig makes it 4 C + 12H+2S.
Absorption of deutoxide of Azote by salts of Protoxide of
Iron. — Priestley first observed that the salts of protoxide of
iron absorb deutoxide of azote ; and Davy afterwards ascer-
tained that a cubic inch of a saturated solution of sulphated
protoxide of iron, absorbs 12 cubic inches of this gas. All
the soluble salts of protoxide of iron, without exception,
possess the property of absorbing a determinate proportion
of deutoxide of azote, which is proportional to the base.
To determine directly the quantity of gas absorbed, Liebig's
apparatus was employed by Pelligot, (Poggendorff's Ann.
xxxi. 24.) The apparatus was weighed, a determinate por-
tion of salt introduced, the weight noted, a little water
poured in, and the weight a third time observed, then it
was attached to a Woulf's bottle by means of a ribband of
caoutchouc, from which the dry gas was disengaged. By
means of this apparatus, with the necessary precautions,
he obtained the following results : —

15*433 gr. (1 gramme) of anhydrous sulphated protoxide
of iron, absorb 4*07 cubic inches (66*7 cub. cent.) or 9* per
cent, of its weight. 15*433 gr. chloride of iron absorb
4*339 cubic inches (71*1 cub. cents) or 10*7 of its weight
per cent.

The solutions which absorb deutoxide of azote are not
altered, for the salts remain in the state of a protoxide, and
can be restored to their former state by heat. Sometimes a
little peroxide of iron is formed, and a little azote is dis-
engaged, but these partial decompositions proceed from the

112 Notice of some Recent [Feb.

independent oxidation of the protoxide, and are not con-
nected with the gas absorbed ; and this is further proved
by the fact, that if the solution is evaporated in a vacuum,
the gas disappears, and the salt remains unaltered. It
may be observed, however, that ferro-prussiate of potash,
does not produce a Prussian blue colour, with the salt in
this state, but forms a reddish brown flocky precipitate,
which changes its colour to blue on exposure to the air.

Phosphate of soda, as well as all salts which by double
decomposition produce insoluble precipitates, with the
salts of protoxide of iron, form when the last salts are
saturated with deutoxide of azote, compounds in which the
gas remains in combination. The precipitate occasioned by
phosphate of soda is reddish brown, and passes in the air
into phosphate of iron. But these combinations are so
extremely unstable, that it becomes almost impossible to
study their nature.

With regard to the other metallic solutions the effect is
quite different. The gas is absorbed by chloride of tin and
nitrate of mercury, but the chloride decomposes the
deutoxide of azote, and takes up the oxygen necessary to
produce an oxide of tin. A solution of nitrate of mercury
saturated with the gas, deposits speedily a crystallized salt
which is a hyponitrate and less soluble than the nitrate.

The circumstances to which we have directed our atten-
tion above, deserve to be prosecuted, as they have no
analogy in mineral chemistry.

Reduction of Chloride of Silver, (Journal de Chimie d'Erd-
mann, 1833, p. 270. J — The best method of reducing chloride
of silver is that of Mohr, which consists in mixing the
chloride with the third of its weight of colphane, and
heating the mixture moderately in a crucible until the
flame ceases to be of a greenish blue colour, then to increase
the heat, for the purpose of fusing the silver and collecting
it at the bottom of the vessel.

BASES.

Method of procuring Selenium. — Brunner employed, for
the purpose of extracting selenium, the refuse from the
sulphuric acid manufactory at Luckawitz, in Bohemia,
(Poggendorff, Ann. xxxi.) The dried refuse is to be distilled

1835.] Improvements in Science. 113

in a glass retort; a small quantity of acid liquor first
passes over, then sulphur follows, which condenses in
the receiver ; 100 parts of the dried matter contains 42
of sulphur. It should then be pulverised and boiled
with a concentrated solution of potash till the solution is
saturated with sulphur. Dilute the liquid with from four
to six times its volume of water, and expose it to the air. In
eight or ten days an efflorescence takes place on the surface
of the liquid, which, as it separates into considerable pieces,
sinks by shaking to the bottom of the vessel. When this
precipitation ceases the substance is to be well washed. It
consists of pure selenium. From the solution a light black
matter separates, which is 'carbon, and may be separated
from the selenium by filtration. If the solution is allowed
to remain for some days in the air, after the separation from
the selenium, a red powder collects on the surface, which
is a combination of sulphur, with a little selenium.

To free the selenium first obtained from a small quantity
of sulphur, it may be again treated with potash, but in this
case, a small quantity of selenious acid remains in solution ;
or it may be oxidized by nitric acid, and precipitated with
sulphate of ammonia.

In the same way the selenium may be separated from the
compound of sulphur and selenium, which appears to be a
combination of sulphuret of selenium with sulphur. If the
solution be exposed to the air after the separation of the
selenium and red compound, for six or eight weeks, more
sulphur is deposited, with a little selenium, which may be
separated by potash.

A small portion of selenium still remains in the liquid,
which may be extracted by saturating the potash with mu-
riatic acid, and then treating the sulphur which separates
with potash as before. But it will be found that the quan-
tity obtained in this way is not worth the trouble of the
process.

The black pulverulent residue which remains after the
distillation of the sulphur, contains a small quantity of
selenium. It consists of silicious sand, charcoal, lead,
lime, iron, alumina and sulphur. To separate the selenium
1 part of the matter is to be heated with 1 part of saltpetre
and 2 or 3 of common salt, in a crucible, until the black

VOL. I. I

114 Notice of some Recent [Feb.

colour is removed and a red tint appears. The mass is then
washed, and boiled with muriatic acid till all the nitric acid
is driven off, and the selenium is then precipitated by sul-
phate of ammonia. From 1 to If per cent, of selenium is
thus obtained from the residue.

Precipitation of Antimony by Sulphuretted Hydrogen, {Ann.
de Pogg. xxviii. 481.) When antimony is precipitated from
the solution of its chloride, in water mixed with tartaric
acid, by sulphuretted hydrogen, it is in the state of a pure
sulphuret, and retains no sensible quantity of chlorine. But
when the gas passed through the liquid is insufficient to
throw down the whole of the metal, the precipitate is, as
M. L. Gmelin observed, a chloro-sulphuret. This com-
pound becomes black by drying on the sand bath, and
exhales fumes of chlorine and antimony.

Economical method of preparing the Protoxide of Copper,
by M. Malagute, {Ann. de Chim. liv. 216.) Fuse with a
gentle heat 100 parts of sulphate of copper, and 59 crystal-
lized carbonate of soda, and continue the heat until the
mass solidifies. Pulverize it, and add exactly 15 parts of
copper filings, then expose to a white heat, and keep it up
for twenty minutes. Powder the cooled mass, and wash it.
The residue is protoxide of copper, of a beautiful colour,
and the first washings contain sulphate of soda, which may
be extracted by evaporation. The oxide thus prepared costs
only 4s. 2d. for 2 lb. 2 oz. 2 dr.

If we were content with calcining the sulphate with
copper, or employed anhydrous carbonate of soda, the pro-
duct would be less beautiful and less pure. The proportion
of carbonate of soda given is sufficient to decompose half of
the sulphate of copper, and a greater proportion, so far from
being advantageous, would afford an oxide much less pure.

Separation of the Fixed Alkalies from Magnesia. — When
the alkalies and magnesia are in the state of chlorides, the
bases may be separated by converting them into sulphates,
treating the solution with acetate of barytes, heating them
after evaporation, and separating by water the soluble alka-
line carbonate from the carbonates of barytes and magnesia.

Formerly, the separation was produced by a strong heat,
which converted the greatest part of the chloride of magne-
sium into magnesia, by the water of crystallization converting

1835.] Improvements in Science. 115

the chloride into muriatic acid. This method, however, is
not correct, because the whole of the chloride of magnesium
is not decomposed, and, by consequence, a portion of it is
obtained along with the soluble salt, and spirits act in the
same way as water. But when chloride of magnesium is
heated in a small platinum crucible, over a lamp with a
double stream of air, and then a bit of carbonate of ammonia
is placed in it, and the heating repeated several times, with
the precaution of moistening the salt with a drop of water,
the magnesia will be completely decomposed. If the dried
residue be dissolved, and tested with nitrate of silver, a
mere trace of the chlorine will only be detected.

Rose endeavoured to separate in this way chloride of
lithium from chloride of magnesium, but of the original
quantity of chloride of lithium, he only obtained 93 per
cent. The remaining magnesia afforded an opalescence
with nitrate of silver. The cause of the difference is, that
part of the lithia, from the presence of carbonate of am-
monia, is converted into carbonate of lithia, which, on
account of its solubility, cannot be readily separated from
the magnesia.

Chlorides of sodium and potassium may be heated
frequently with carbonate of ammonia, without changing
their weight. Chloride of calcium, on the other hand,
undergoes a similar change with the chloride of lithium.

By access of the air, the chlorides of potassium and
sodium are changed, and therefore, the preceding state-
ment must be understood as referring to their behaviour in
a covered crucible.

Rose has made some experiments upon the volatility of
chlorides of sodium, potassium, and lithium, which are
very important.

1*0255 grms. of chloride of potassium lost by a red heat
in a small platinum crucible 6 lines in depth during the first

quarter of an hour - 0*0845

During the second quarter - - - - 0*0890

1*016 chloride of sodium in the same vessel during the

first quarter 0*038

During the second quarter - - - - 0*039

A mixture of 0*932 grms. chloride of potassium, and
1*175 chloride of sodium, lost in the same circumstances

i2

116 Notice of some Recen t [Feb .

0-065. From which it appears that in mixture they retain
the same volatility as when separate. Chloride of lithium
is more volatile than either of the other chlorides.

1-134 chloride of potassium heated in a large crucible,
18 lines deep, lost in the first quarter of an hour 0*026 grm.
In the second quarter 0*0265

1.101 grms. chloride of lithium in the same circum-
stances lost in the first quarter ------ 0*017

In the second quarter ------- 0*013

1-100 grms. of chloride of sodium in the first

quarter 0*007

In the second quarter ------- 0*009

The relative volatilities, therefore, of these salts, begin-
ning with the most fixed, is chloride of sodium 1, chloride
of lithium 1J, chloride of potassium 3J, in a deep crucible,
but in a shallow crucible the proportions are different, the
volatility of the chloride of sodium being represented by 1,
and that of chloride of potassium hj2^,(Pogg. Ann. xxxi.)

Manufacture of Artificial Soda. — The calcined sulphate of
soda is converted into sulphuret of sodium, by heating it
with pulverized charcoal. The sulphuret is dissolved, and
oxide of copper added to the hot liquid. The liquid is
evaporated after filtration until its spec. grav. be 1*41 or
1*48. Then, on allowing it to remain from 24 to 28 hours,
the undecomposed sulphate of soda crystallizes. The super-
natant liquid is evaporated to dryness. By this process,
for every 100 parts of sulphate of soda, 65 of caustic of
soda are obtained. It may be converted into carbonate by
heating with charcoal.

Metallic copper, as well as its oxides, can separate the
sulphur from the sulphuret of sodium, but in general the
protoxide is preferable. To procure this oxide, metallic
copper is to be heated to redness, and plunged into water
containing in solution 0*02 of nitrate of soda from Chili.
The sulphuret of copper, which is the product of this pro-
cess, mixed with -6 of sulphur in powder is easily converted
into sulphate by heat. These processes are followed at
Hof., according to Prukkner, (Annal de Schweigger, b. vii.)
Separation of the Oxide of Cobalt from Oxide of Nickel,
{Ann de Chim. lvi. 333.) — M. Persoz separates these oxides
by dissolving them in nitrate or muriatic acids, adding as

1835.] Improvements in Science. 117

much paraphosphoric acid as will saturate the two oxides.
Ammonia is poured in, which forms a precipitate re-dis-
solved by an excess of ammonia, and the liquid becomes
violet coloured. When allowed to stand the excess of alkali
flies off, and the solution becomes turbid in consequence of
the deposition of ammonia paraphosphate of nickel, which
at first possesses a greyish colour, but ultimately becomes
green. When the precipitate completely subsides, the rose
coloured supernatant liquor is drawn off, which, if it con-
tains no more nickel, may be evaporated to the consistence
of a syrup. The paraphosphoric acid may be separated from
the oxides by carbonate of soda.

Separation of Oxide of Cadmium from Oxide of Bismuth. —
Persoz has observed that the paraphosphate of bismuth is
insoluble in ammonia, and that the paraphosphate of cad-
mium is very insoluble. Hence, this is a ready method of
separating the two oxides. He prepares the acid by calcin-
ing pure phosphate of ammonia.

Separation of Oxide of Uranium from the Oxide of Cobalt,
Nickel, and Zinc. — The subacetate of lead separates the
oxide of uranium from the other three oxides, for a solution
of this salt poured into a solution of uranium in nitric acid,
occasions a precipitation of uraniate of lead, the other oxides
present not being affected.

Manufacture of the Tarn Tarn and Cymbals of the Chinese,
(Ann de Chim. liv. 329.) — According to M. Stanislaus Julien,
the Chinese in the formation of the tam-tam, run the alloy
into leaves, and then fashion it in the proper way; but
according to Darcet this is impossible, because the alloy is
as brittle as unanealed glass. The tam-tam and cymbals
consist of

Tin ... . 0-20
Copper . . 80

100
The most probable mode of manufacture appears to be
by running a piece modelled in sand in a font with the
alloy. The piece taken from the mould is finished off, and
tempered like steel. If it is distorted by being plunged
while hot into cold water, the injury is rectified by a ham-
mer. The tone appears to be given either by the tempering

118 Notice of some Recent [Feb.

or by proper hammering. It is then polished by a lathe,
and completed.

Method of obtaining Iridium and Osmium, after the separa-
tion of Platinum, by F. Wohler. (Pogg. Ann. xxxi.) — The
black pulverulent residue which remains after the solution
of native platinum in aqua regia, contains, besides the com-
bination of osmium and iridium, a considerable quantity of
free iridium, and some iron titanium. Wohler recommends
the following process for separating them : Mix equal por-
tions of the residue and decrepitated common salt, and
place them in a green glass tube, which is to be passed
through a tube furnace similar to that in the apparatus of
Liebig. To one end is fixed an apparatus for the production
of chlorine, and the other communicates with a vessel filled
with ammonia, preceded by a bulb for the absorption of the
oxide of osmium . Under the tube, hot coals are to be placed, in
order that the mixture contained in it, which should occupy
three fourths of its diameter, may be exposed to a strong
heat. The chlorine is then allowed to pass through the
tube. By this operation sodium-chloride of iridium, and
sodium-chloride of osmium are formed, both of which salts
are soluble in water, while the iserine remains insoluble.
A little chloride of osmium will be formed in the first
portion of the tube. The greater portion of the oxide of
osmium will have crystallized in the bulb situated at the
extremity of the tube. The bulb is to be exposed to a heat
so as to melt the oxide, and in this state it may be poured
into a flask or glass tube. The tube may be placed on one
side, so as to allow the oxides to sublime in the form of
long crystals on the opposite side.

To the ammonia, which contains more or less oxide of
osmium, and is coloured yellow by it, let some sal-ammoniac
and carbonate of soda be added, and let the whole be then
evaporated to dryness, and heated to redness in a glass re-
tort. By this method the oxide will be reduced to the
metallic state, which, by treating with water, will remain
in the form of a black powder. It is then washed and dried.
The oxide in the bulb may be reduced in the same manner
after it has been dissolved in ammonia.

When the tube with its contents is placed in a cylindrical
vessel full of water, all the soluble portion dissolves. A

1835.] Improvements in Science . 119

deep brownish red solution of double salt of iridium is
formed. The liquid after standing should be decanted
from the residue, which consists of iserine, and some pieces
of osmium and iridium. The fluid drawn off is distilled
to separate the oxide of osmium, which may still exist in it.
When the whole of the acid has passed over, the distillation
is stopped and the solution filtered. It is then to be eva-
porated over a fire, and during the concentration, carbonate
of soda is to be added in excess, which throws down a
blueish black precipitate.

The dried black mass will then be strongly heated in a
Hessian crucible, and after cooling, be digested in water.
The residue is a sesquioxide of iridium. The filtered salt
solution contains, besides common salt and carbonate of
soda, also chromate of soda, which gives it a yellow colour.

The sesquioxide of iridium contains, besides osmium, some
oxide of iron. It is to be placed in a glass tube, and hydro-
gen passed over it at a red heat till water ceases to be
formed. Metallic iridium thus obtained is a black powder.
It contains much caustic soda, which was chemically com-
bined with sesquioxide, and is now taken up by water.
By digestion in muriatic acid the iron is removed. After
washing, it may be placed between layers of filtering paper,
and pressed for several hours with a screw press. Heated
then in a crucible, it is obtained in the form of a firm polished
grey mass. Metallic iridium may be obtained by a shorter
method, but not In such purity; by evaporating the solution
of sodium chloride of iridium to dryness, heating to redness,
so as to melt the salt, and begin to volatilize the chloride of
sodium. The iridium will thus be reduced, and remain,
after digestion in water, as a grey or black metallic powder.

Use of Iridium in the manufacture of Porcelain. (Pogg.
xxxi.) — The substances hitherto employed for painting
porcelain consisted of combinations of oxide of iron and
oxide of cobalt, the former producing grey and Indian ink
tints, and the latter the brown or blueish hues. It has been
lately ascertained, however, that iridium and rhodium
communicate to porcelain grey and black tints. The black
colour of iridium is very deep and pure, while its grey tint
is complete, without any tendency to blue or brown. The
residue from the Russian platinum mint contains iridium,

120 Notice of some Recent [Feb.

and is now employed at the Royal Berlin Porcelain Manu-
factory for painting the superior kinds of ware.

Separation of Lead and Bismuth.* — Stromeyer dissolves
both oxides in nitric acid, and boils the solution with an ex-
cess of caustic potash. The oxide of bismuth loses its water
and remains in the form of a yellow powder, while the
oxide of lead dissolves in the potash. The solution is
saturated with acid, and precipitated with an alkaline
oxalate.

To detect Copper in Lead by the Blowpipe. f — Plattner
recommends the following plan for this purpose : The lead
containing the copper is reduced upon charcoal to a small
melted globule. Twice its weight of boracic acid is added ;
and the globule being so placed as half of it to touch the
acid and half the charcoal, it is melted into a glass. The
lead oxidizes and dissolves in the acid. In this way the
lead is so oxidized that the small residual globule will
readily afford with the salt of phosphorus and tin the
peculiar characters of copper.

ACIDS.

Distillation of Nitric and Muriatic Acids. — According to
Wittstock, if a quantity of saltpetre be distilled with a
third of its weight of dilute sulphuric acid, sufficient to
form a bisulphate of potash, a sudden and rapid extrica-
tion of nitric acid takes place at the time, when the clear
mixture becomes milky, by which the liquid from gently
boiling, is forced into violent ebullition, and a great quan-
tity of salts is deposited in the retort. A similar occurrence
takes place when common salt is distilled with sulphuric
acid in sufficient quantity, to produce bisulphate of soda.
A strong ebullition being observed on the deposition of this
salt. (Poggendorffs Ann. xxxi. 31. )

Crenic and Apocrenic Acids. — In subjecting to analysis
the water of the well at Porla in Oerebro, Berzelius dis-
covered two new acids.J (Poggendorffs Ann. xxix. 1.)
When the water is exposed to the access of air, a yellow

* Poggendorff, xxvi. 553. Berzelius Jahresbericht, 1834, 151.

t Pharm. Centrall. iii. 859.

X Porla well lies in the country of Oerebro, on the boundary of the parishes of
Skagerhult, Viby, and Bodarne, on the edge of a great moor, which extends to
no great depth (3 ellen) covered with sphagnum palustre, and resting on a hard
bottom of sand and gravel.

1835.] Improvements in Science. 121

deposit or ochre precipitates. The water yields in ^J^

parts,

Chloride of potassium 0*3398

Chloride of sodium 0*7937

Soda combined with crenic acid . . . 0*6413
Ammonia combined partly with crenic acid

and partly with carbonic acid . . . 0*8608

Bicarbonate of lime ....... 9*0578

Bicarbonate of magnesia 1*9103

Bicarbonate of manganese 0*0307

Bicarbonate of iron 6*6109

Phosphate of alumina 0*0110

Silica . 3*8960

Crenic acid 5*2535

29*4058
From the ochry deposit the new acids are obtained. It
consists of

Crenate* of iron 90*54

Carbonate of lime 3*54

Phosphate of alumina with trace of magnesia

and manganese 0*38

Silica 5*54

100*00
The temperature of the water is 44°* 6 F, and the gas
which is continually rising from the bottom of the well,
consists of 6 vols, of azote and 1 carbonic acid.

Berzelius treated this deposit in the following manner :
the ochre was boiled with caustic potash, which produced
a brown solution, from which some ochre was deposited
after standing for some time. This precipitate was thrown
on a filter, the filtered solution boiled and iron deposited,
sulphuretted hydrogen being passed through the liquid,
the remaining iron in solution was separated.

Crenic acid, (Kprjvr] a well) was obtained from the alka-
line solution by the following process *. The liquid was
supersaturated with acetic acid, and acetate of copper
added. If the precipitate was green, the acid was added
in greater quantity. Acetate of copper was then added as
long as a brown precipitate continued to fall. The crenate
of copper remained in solution in the acetic acid, and when

122 Notice of some Recent [Feb.

it apparently precipitated, it dissolved again, leaving apo-
crenate of copper.

This is slightly soluble in the filtered liquid, but when
washed, it is completely dissolved. These washings were not
mixed with the liquid passing through the filter. The latter
was saturated with carbonate of ammonia in slight excess.
and then was gently heated to 50° C (122° F) when the
crenate of copper fell down. As long as the solution con-
tinues green, it is a proof that the precipitation is not
completely effected, and is to be remedied by the cautious
addition of carbonate of ammonia, or by heating the solu-
tion. The crenate of copper possesses a light grey-green
colour, if brown, it contains apocrenic acid.

It was then washed, mixed with a little water, and a
current of sulphuretted hydrogen passed through it. The
sulphuret of copper thus obtained was brown, and the solu-
tion which passed through the filter was also brown.
After standing 24 hours in a corked flask, it was filtered.
The metallic sulphuret was so much the longer in separat-
ing from this solution, in proportion to the quantity of
water added. It frequently happens, that when the solu-
tion passes through at first clear, the metallic sulphuret
begins to follow during the process of washing, in conse-
quence of the formation of bicrenate of copper. The
brown solution was heated in a corked flask at a tempera-
ture of 80° C (176° F,) and thrown on a filter. The filtered
crenic acid formed a pale yellow solution, which must be
kept from the access of the air, for then it is converted
into apocrenic acid. By evaporation, free from the contact
of air, a dark yellow mass was obtained, consisting of
crenic acid, crenates of lime, magnesia and manganese,
which was treated with absolute alcohol. Crenic acid and
a trace of crenate of magnesia were taken up, while the
other bases remained as acid salts. The alcoholic solution
was evaporated, free from the contact of air. The residue
possessed a yellow brown colour. It was dissolved in
water, and mixed with a solution of acetate of lead. The
first precipitate formed was brown, which partly dissolved,
leaving a brown residue of apocrenate of lead. The so-
lution was filtered and precipitated with acetate of lead.
The precipitate was well washed, dried, excluded from

1835.] Improvements in Science. 123

the air, and a current of sulphuretted hydrogen passed
through it.

The filtered solution possessed a pale yellow colour,
which by evaporation, free from the action of air, yielded
a thick pale opaque yellow mass, which was crenic acid in
the purest state.

Crenic acid is yellow, destitute of any appearance of
crystallization, without smell, and in the dry state it tastes
acid, but in a dilute solution, produces no effect on the
tongue, although it reddens litmus paper. It dissolves in
all proportions in water and absolute alcohol. The alco-
holic solution evaporated in the air becomes brown. The
aqueous solution when dried assumes the appearance of a
syrup. When distilled, it affords an acid liquor and a
brownish yellow oil. Distilled with caustic potash, ammo-
nia is produced. While in the retort charcoal remains,
which burns completely away when the acid is pure.
Crenic acid consists of carbon, hydrogen, azote and oxygen,
in proportions which have not yet been determined.

It dissolves in nitric acid in the cold without change ; by
the application of heat some nitrous gas is disengaged,
and nitric acid may be distilled off. By evaporation a yel-
low mass is left in the water, possessing an intensely bitter
taste, which unites with an alkali when the latter is added
to it, forming an alkaline crenate.

When silica is separated from a crenic acid solution, the
precipitate contains crenic acid which can be separated by
an alkali; but the silica by heating becomes black and
disengages an animal smell, and when moist is dark grey,
when dry, white.

The compounds of crenic acid and the alkalies are easily
soluble in water, and in concentrated solutions resemble
vegetable extracts. The salt3 of the alkaline earths are
less soluble, and those of the metallic oxides difficultly
soluble, but dissolving more or less by washing.

To determine the atomic weight of crenic acid, a solution
of acetate of lead was precipitated by a portion of pure cre-
nic acid ; the precipitate was white by reflected, and yellow
by transmitted light. It was washed and dried, free from
access of air at a temperature of 100° C (212° F.) It weighed
0*59 grm. ; decomposed by sulphuric acid 0*4165 grm. of
sulphate were obtained, dried at the same temperature.

124 Notice of some Recent [Feb.

After being heated in a platinum crucible, by which
operation it first became brown and gave out smoke, it
assumed a white appearance and weighed 0*41 grm., ac-
quiring no change by treatment with nitric acid. This
product is the apocrenic acid combined with the sulphate
of lead. Now as the weight of an atom of sulphate lead is
to the crenate of lead as 41 to 59, the atom of crenic acid
is 1333*4. By analyzing the crenate of lime Berzelius
obtained for the atomic weight of the acid 1358*38.*

Apocrenic Acid. — Apocrenate of copper is precipitated
when the ochre has been treated with potash, and acidified
by acetate of copper. This is washed twice with cold water,
It is then to be mixed with a little water and a stream of
sulphuretted hydrogen passed through it. The solution is
dark brown, and by concentration blackish brown. By
absolute alcohol the pure acid is taken up and freed from
the salts. A small portion remains on the filter with the
sulphuret. This is taken up by acetate of potash, the
solution evaporated, and the apocrenic acid dissolved in
alcoholofsp.gr. 0*864. The acid may then be separated
from the potash by means of muriatic acid.

To ascertain the atomic weight, apocrenates of lead and
barytes were analyzed. By the former the numbers were
1693*0, and by the latter 1642*2.f

Action of Formic Acid upon some oxides and peroxides of
metals. — 1. Gobel finds (Schweigg Seidel, vii.) that solutions
of gold, platinum, and palladium are not decomposed by free
formic acid even at the boiling point. This acid volatilizes
gradually without separating the least trace of metal ; but
the formate of soda completely precipitates these metals
partly in brilliant spangles, and partly in the form of powder.
The solutions of nitrate of silver and mercury are decom-
posed by free formic acid ; but the decomposition is more
rapid by means of the alkaline formate.

2. The red oxide of mercury affords an easy method of
determining the quantity of free formic acid, either mixed
with other acids or combined with bases. The proportion

* If we reduce these weights to convenient numbers, we have for a mean
13*458 which approaches 13-5 so nearly, that we can have no hesitation in admit-
ting itas the atom of crenic acid. — Edit.

t 16-75 appears, therefore, the atom of apocrenic acid.— Edit.

1835.] Improvements in Science. 125

of formic acid may be judged of by the volume of carbonic
acid disengaged, when a liquid containing formic acid is
heated with red oxide of mercury. The carbonic acid
should be collected and estimated in a proper apparatus.

When formic acid is combined with bases, it is necessary
to add, besides the red oxide of mercury, some acetic acid
to set the formic acid at liberty.

3. The formates of zinc, copper, cadmium, bismuth, lead,
nickel, uranium, cerium, and cobalt, when exposed to a red
heat in a glass tube over a spirit lamp, are decomposed and
their oxides are completely reduced. If the flame of the
blowpipe is directed upon the more difficultly fusible metals,
while in the tube they appear through the glass to possess
the metallic lustre peculiar to them. The employment of
formic acid for procuring the rare metals, is to be preferred
to hydrogen, and as the price of formic acid is low, it is to
be hoped that the reduction will be speedily made on a great
scale.

4. Formic acid may also be used to determine the quan-
tity of oxygen contained in the peroxides. For this purpose
a determinate quantity of the peroxide is heated with formic
acid. The gas disengaged, which is a mixture of carbonic
acid and common air, should be collected, and the quantity
of carbonic acid determined by means of caustic potash
noting the barometric pressure, the temperature and mois-
ture, and by dividing the volume of the acid by 2, the
quotient expresses the volume of oxygen taken from the
peroxide. Its weight is then calculated.

5. The method recommended by Dobereiner of preparing
formic acid with sugar, is a very good one. The acid thus
obtained always contains some acetic acid, which is de-
tected when it is treated with red oxide of mercury. The
acetic acid may be separated by employing instead of chalk,
as recommended by Dbbereiner, carbonate of lead, to satu-
rate with the assistance of heat ; the acid liquid passing over
in distillation, and separating by crystallization the formate
of lead which is less soluble than the acetate, which dis-
solves easily. The formate is distilled with sulphuric acid
previously diluted with its weight of water, and pure con-
centrated formic acid is thus obtained possessing an acid
and agreeable odour.

126 Notice of some Recent [Feb.

Malic Acid, — Liebig recommends ( Poggendorff Ann.
xxviii.^) the following process for obtaining this acid. Add
carbonate of lime or some other alkaline carbonate to the
boiled and filtered juice of the service tree till it is neutral-
ized. Mix the neutral solution with nitrate of lead until
precipitation ceases, and allow the liquid to remain in a warm
place some days. During this time the flocky precipitate
is converted into yellowish white needles. Acetate of lead
may be employed in place of the nitrate ; but a quantity of
colouring matter is thus precipitated. The impure malate
of lead is now to be boiled after washing with dilute sul-
phuric acid till it loses its granular appearance. To the
thick matter, which contains sulphate of lead, sulphuric
acid, malic acid, colouring matter, and other acids, a solu-
tion of sulphuret of barium is now to be added in small
portions. The clear solution will now be filtered, saturated
with sulphuret of barium and carbonate of barytes, and
heated to the boiling point. Tartrate or citrate of barytes
remains undissolved. The pure malic acid is obtained
when the barytes is saturated with dilute sulphuric acid.
If any barytes should remain in solution, the addition of a
little spirit of wine will separate it.

By analyzing the malate of silver organically he ascer-
tained the constituents of malic acid to be

Carbon 41*47

Hydrogen .... 3*51
Oxygen 55*02

100-00
M. Jules Gay Lussac found in 1832, the composition of

citric acid, Carbon 42*05

Hydrogen .... 3*57
Oxygen 54*38

100*00
Hence, if these analyses are correct, we have the com-
position of each represented by

4 atoms carbon . . 0*25
\ 2 atoms hydrogen . 3

4 atoms oxygen . . 4

7*25
and their formula is40 + 4C + 2H.

1835.] Improvements in Science. 127

Malate of silver may be obtained by mixing nitrate of
silver and malate of ammonia. It is a white granular
precipitate, becoming yellow by drying, and consists of

66*53 oxide of silver, and 33*47 malic acid. It dissolves
in hot water, and metallic silver precipitates on cooling.

Malate of zinc consists of oxide 37*75, and 62*25 of acid.

The crystallized salt has 3 atoms of water, which are
driven off at 240°.

Malate of magnesia is formed of 23*45 magnesia, and
76*55 acid.

Malate of barytes, when formed from a solution of a
malate is deposited by evaporation, in the form of a white
crust, which is insoluble in cold and hot water, but readily
on the addition of a drop of nitric acid. It consists of
56*441 barytes, and 43*559 malic acid.

Paramedic Acid. — Winckler described an acid under the
name of fumaric acid, (Jahresbericht 247,) which M. Demar-
cay has shewn (An. de Chim. lvi. 429,) to be paramalic acid.

It is obtained from the juice of the fumaria officinalis, by
treating it with animal charcoal, and precipitating by acetate
of lead. The precipitate being washed, and a little water
added, it is to be decomposed by sulphuretted hydrogen.
By nitration a clear liquor is obtained, from which crystals
of paramalic acid are separated by evaporation. Hitherto
this acid has only been obtained by the decomposition of
malic acid. The paramalate of silver, when analyzed,
afforded for the composition of the acid

Carbon 41*84

Hydrogen . . . 3*41
Oxygen . . . .54*75

100*00
It dissolves with difficulty in cold water, more readily in
hot, and the solution affords by cooling arborizations. It
has an acid, styptic taste, volatilizes, and is sublimed by heat ;
forms crystallizable salts with ammonia and lime. It has
no smell, and dissolves in alcohol and ether. JNltric acid
sp. gr. 1*4 dissolves it completely, and fine needles separate
on cooling.

Pyrotartaric Acid. — This acid is prepared by distilling
tartaric acid, between the temperatures 337° and 374°.

128 Notice of some Recent [Feb.

The liquid obtained is introduced into a glass retort, and
distilled till it acquires the consistence of syrup ; the
receiver is then changed, and the distillation carried to
dryness. The last liquid which comes over is exposed to a
severe cold, or to spontaneous evaporation in vacuo. Yellow
crystals separate, which are pressed between blotting paper
and again re-dissolved in water. On cooling, crystals of
pure pyrotartaric acid are deposited. An analysis of this
acid afforded Carbon .... 52*11

Hydrogen . . . 5*30
Oxygen . . . . 42*59

100*00
This acid is white, destitute of smell, very soluble in
water and alcohol, with a taste resembling tartaric acid.
It melts at 212, and boils at 370°. Acetate of lead precipi-
tates it ; the white product is insoluble in water, but very
soluble in an excess of acetate. Pyrotartrate of potash,
when poured into a solution of the proto-nitrate of mercury,
produces a copious white precipitate, and forms with per-
sulphate of iron a yellow precipitate, soluble in twice its
weight of water ; with sulphate of copper a green product
which requires nearly the same quantity of water to
dissolve it.

Pure benzoic acid may be procured, according to Righini,
by dissolving the acid in four or five times its weight of
sulphuric acid diluted with six parts of water, adding
during the ebullition, a small portion of animal charcoal,
and filtering. On cooling the acid separates in crystals.
This process may be repeated if the crystals are not pro-
perly formed, and there is any smell. To obtain the cry-
stals in perfect purity, they may be dissolved in alcohol,
and the solution exposed in a subliming apparatus on the
sand-bath, the heat being applied in such a manner that
the alcohol alone is volatilized. The acid is thus obtained
in long needles, perfectly white and destitute of smell.
(Ann. de Chim. lvi. 444.)

Sulphobenzoic Acid. — This acid is formed by adding
benzoin to sulphuric acid as long as any of it is taken up,
allowing the flask to cool occasionally during the decom-
position. (Poggendorff, xxxi.) By dissolving the acid in

1835.] Improvements in Science. 129

water, a peculiar substance separates, which, from its pro-
perties, Mitscherlich terms a sulpho-benzoide. The acid is
saturated with carbonate of barytes, and the solution being
filtered and mixed with sulphated protoxide of copper,
large crystals of sulpho-benzoate of copper are obtained.

The sulpho-benzoates of zinc, protoxide of iron, silver,
potash, soda, ammonia, and many other salts, crystallize
well. The copper may be removed by sulphuretted hydro-
gen when the acid evaporated to the consistence of a syrup,
assumes a crystalline appearance, and is decomposed by a
strong heat. Sulpho-benzoate of copper may be exposed
to a temperature of 220° (328° F) without undergoing
decomposition, or affording a precipitation with solution of
barytes. Anhydrous sulpho-benzoate of copper, analyzed
by oxide of copper, yielded

Carbon 38*58

Hydrogen 2*62

Sulphur 16-94

Oxygen 21*03

Protoxide of copper 20*84

100-02
The acid may be considered therefore as composed of one
atom benzine and two atoms sulphuric acid.

SALTS.

Double salt of chloride of calcium, and oxalate of lime.
According to Julius Fritzche, when oxalate of lime is dis-
solved in warm concentrated muriatic acid, on cooling a
double salt of muriate of lime and oxalate of lime crystal-
lizes. By pressing the crystals on paper the free acid may
be taken up. and on placing them in water the muriate of
lime dissolves and the oxalate of lime remains. The latter,
after heating and solution in nitric acid, affords no precipi-
tate, or merely a slight opalesence with nitrate of silver, and
the solution gives no trace of oxalate of lime by ammonia.

This presents an easy method of analyzing the salt, by
digesting it in a platinum capsule, filtering, and then pre-
cipitating the lime from the filtered solution by oxalate of
ammonia. 2*563 grm. of the double salt gave 0*707 carbo-
nate of lime from the residue, treated with water and 0*705

vol. I. K

130 Notice of some Recent [Feb.

carbonate of lime from the portion dissolved in water. The

salt consists of

Oxalate of lime 0-904

Chloride of Calcium - - - - 0*778
Water 0-881

2-563
Double salt of chloride of calcium and acetate of lime. (Pog.
Ann. xxviii. 21 .) The combination of chloride of calcium
with acetate of lime is easily obtained by dissolving small
portions of both in water, and allowing the solution to eva-
porate. The double salt separates in large crystals. It is
very soluble in water. Analyzed by oxalate of ammonia
and nitrate of silver the constituents were

Acetate of lime - - - - 0*711
Chloride of calcium- - - 0*500
Water 0*789

2*563
Sulphated Protoxide of Iron, and Chloride of Iron. — Bons-
dorff has shewn, (Poggendorff, xxxi.) 1. That sulphate of
iron may be obtained completely free from peroxide, by
rendering, before crystallization, the solution acid, which
has been made neutral by boiling.

2. That this salt, moderately dry or moist, is not altered
by exposure to the air ; but in dry air, or in a temperature
of 104° F, in the course of time it gradually decomposes.

3. There are three varieties of vitriol, the first greenish
blue, formed from an acid solution free from peroxide ; the
second dirty green, from a neutral solution without per-
oxide ; and the last emerald green, from a solution impreg-
nated with peroxide salt.

4. Chloride of iron may be obtained pure by rendering
the neutral solution slightly acid by means of muriatic acid,
and drying the crystals in a temperature between 86° and
104° F, mixed in a close vessel with a little chloride. At a
temperature of 122°, and in dry air, the chloride falls to a
white powder.

5. The primitive form of the chloride of iron is an oblique
rhombic prism, and its atomic composition 1 atom chloride
of iron and 4 atoms water.

Solubility of Bitartrate of Potash. — Brandes and Warden-

1835.] Improvements in Science. 131

burg have made experiments upon the solubility of this salt,
and have found that at 212° F, 100 parts of water dissolve
6*68 parts of the salt.

100 parts water at 167° dissolve 4*55
„ 199° „ 2-64
75° „ 1-12
66° „ 0-49
The method of experiment was to allow a solution, satu-
rated at a high temperature, to cool down to the requisite
point, (Annalen der Pharmacie i. 7.)
To be continued.

Article V.

On a deposit of recent Marine Shells , at Dalmuir,
Dumbartonshire. By Thomas Thomson, Esq.

The coal formation of the South of Scotland, which extends
from the firth of Forth to the firth of Clyde, is closed
towards the west by the Kilpatrick hills, an extensive
greenstone chain which terminates in the Clyde, by the
rock upon which Dunglass Castle, the termination of the
Roman wall, is built. On the south side of the Clyde the
coal field extends a little further, but there also it fs inter-
cepted by a range of greenstone and porphyry rocks, consti-
tuting the hills to the south of Greenock. To the west of
the Kilpatrick hills, on the north side of the river, we find
the beautiful white or reddish but non-fossiliferous sand-
stone of the neighbourhood of Dumbarton and Helensburgh,
and in the vicinity of the latter place there is also found a
vast quantity of red sandstone conglomerate, which there
rests immediately on the clay-slate. This is the same con-
glomerate which is found on the south side of the river
below Greenock, as well as in the island of Arran, and along
the coast of the county of Ayr, and at Campbeltown in the
Mull of Cantire. In all which places this conglomerate
occupies a stripe of land adjoining the seacoast, while
the interior of the country consists, about Greenock of
greenstone, about Helensburgh and in Arran of clay-slate,
and in Ayrshire of the coal beds.

The rocks in the neighbourhood of Glasgow are in many
places covered with alluvial deposits, the nature of which

k2

132 Mr. Thomas Thomson on a [Feb.

varies very much in different places. In some parts of the
immediate neighbourhood of this city, we find low hills of a
thick miry clay, full of water- worn stones, and quite des-
titute of fossils. In others, and particularly under Glasgow
itself, there occurs a deposit of very pure sand, of consider-
able thickness, rising in one or two places to a considerable
elevation. This arenaceous deposit would appear to extend
to a considerable distance, since the red conglomerate in the
neighbourhood of Helensburgh, at the distance of twenty-
six miles from Glasgow, is also covered with a very line
sand to the depth of eight or ten feet, in which shells are
said to have been found during the digging of the founda-
tions of Roseneath Castle. Here, however, there is also
interposed between the sand and the secondary rocks, a bed
of stiff clay very similar to the clay about Glasgow, by the
position of which we may perhaps conclude, from analogy,
that the corresponding clay at Glasgow is below the sand,
and though no distinct section has there been obtained, yet
the more frequent occurrence of the arenaceous beds might
perhaps lead us to the same conclusion.

In the neighbourhood of Dalmuir, about 8 J miles from
Glasgow, a section of the sand deposit is exposed by a small
stream known by the name of Dalmuir burn. A few years
ago, the proprietor of that part of the country found it con-
venient to alter the course of this stream. During the
formation of the new course a great deal of sand was cut
away, and in one particular place the workmen were sur-
prized to find that they were digging through a mass of
shells. The extent of the spot in which the shells are
found is so limited that it would probably have remained
unknown had not the overseer of Mr. Dunn's estate been
kind enough to point it out to me when I was in that
neighbourhood collecting fossils from the shale beds con-
nected with the coal.

The locality in which the fossils are exposed is situated on
the banks of the Dalmuir burn, about 100 yards above the
bridge by which the road from Glasgow to Dumbarton crosses
it, and about a mile from the Clyde. The current of the
stream is not very rapid, so that the bed of shells is probably
not more than 20 feet above the level of the Clyde, which at
that place is sensibly salt at high water. The breadth of

1835.]

Deposit of Recent Marine Shells.

133

the channel of the stream at this place is about 14 feet, and
the depth of the banks is about 2£ feet. The sandy deposit
appears to extend on both sides of the stream, upwards and
downwards without alteration, but the fossils are confined
to a circular or rather elliptical space, the breadth of which
(across the stream) is about twenty-five feet, while its length
is only about 15 feet. The deposit extends back from each
bank only about 6 feet, so that more than one half of the
whole mass has been cut away during the change of the
course of the rivulet. The whole depth of the bed, as it
exists at present, is about 2£ feet, but I am informed by the
overseer upon the estate, who superintended the workmen
during their operations, that after the soil had been removed,
ten or twelve feet of earth full of sand was carried away, so
that the depth of the bed in its original state must have
been 12 or 14 feet.

The number of species which have been already collected
in the situation described amount to about thirty.

I have been greatly indebted to Mr. Sowerby for his
assistance in determining their names.

I. Echinus Esculentus.

Shells.

1. Balanus costatus

2. Mya truncata

3. Amphidesma Boysii

4. Saxicava rugosa

5. Tellina tenuis

6. Lucina flexuosa

7. Cyprina vulgaris (pro-

bably)

8. Cardium edule

9. Nucula minuta

10. Astarte minima

11. Anomia ephyppium

12. Mytilus edulis

13. Modiola albicostata
Pecten Islandicus

14
15

pusio

Lottia parva (Patella p
Montag.)

1 7 # pissurella Noachina ( Ce-
moria Flemingu, Leach
MSS.J

18. Helix levigata (Montag.)

19. Velutina communis

20. Natica glaucinoides

21 . Littorina vulgaris

22. Trochus cinerarius

Margarita 1

Rissoa 1

23.
24.
25.
26.
27.
28.
29.
30.

Lacuna vincta
Fusus Bamifius
lamellosus

Buccinum undatum
> striatum NS.?

* The Fissurella Noachina has been found at Oban, Argyleshire, by Mr. Lowe,
See Zoolog. Journ. Mr. Sowerby has compared a specimen from Dalmuir with

134 Mr. Thomas Thomson on a [Feb.

The last shell was marked by Mr. Sowerby as a new
species of Buccinum. Although approaching B. undatum,
it may be distinguished by the following characters : —

1. Buccinum striatum.

B. Anfractibus longitudinaliter undatis, transversim striatis,
parum convexis, costis longitudinalibus fere rectis.

This buccinum approaches nearly to B. undatum, from
which, however, it is easily distinguishable by several
particulars.

If B. undatum be examined with a microscope, it will be
found that the transverse ridges are elevated, broad and
distant, and there is between each of these ridges, in the
upper whorls, a narrower and less elevated ridge, and in
the lower or newer part of the shell, generally about three.
Now, in B. striatum, the ridges are so flat that the shell
may much more properly be said to be spirally striated,
than covered with transverse ridges. The whorls in the
new shell are also much flatter than in B. undatum, and the
longitudinal undations which in that shell are considerably
concave towards the mouth of the shell, are here almost
quite strait. F. lamellosus possesses the following cha-
racters :

2. Fusus lamellosus.

F. oblongus, longitudinaliter costatus, parte superiore an-
fractuum subangulato ; anfractibus 10 costatis, costis
elevatis ad aperturam testae, concavis, supra subspi-
nosis ; apertura ovali, cauda breviori quam apertura,
late canaliculata, parum reflexa.
This pretty little fusus is about 5 lines in length, and 2£
in breadth, being more minute than recent specimens. Each
whorl is furnished with ten longitudinal ribs, and the inter-
stices are perfectly smooth. The ribs are considerably
elevated and acute, and are rather prominent on the upper
part of the whorl, which is slightly angled. There they
rise so as to form small teeth, beyond which they are con-
tinued obliquely along the flat part of the whorl, quite to
the suture. The canal is open, and rather wide, but not so

the Cemoria Flemingii of Leach in the British Museum, and has ascertained their
identity. The Fusus lamellosus, is the Murex lamellosus of Lamark, and a
remarkable circumstance connected with the history of this shell is, that hitherto
it has only been found in the South Sea, at the Falkland Islands, with a specimen
from which locality I have been favoured by Mr. Sowerby. — Edit.

1835.] Deposit of Recent Marine Shells. 135

long as the aperture. It is turned to the left, and is a little
reflexed.

The shells which have been found in the Dalmuir sand
have in general lost all colour, and become of a dull yellowish
white, but otherwise, though brittle, they are in a state of
beautiful preservation. They appear to be all natives of
the British seas, with the exception of the F. lamellosus,
which has only been observed about the Straits of Magellan,
and Natica glaucinoides, which is a crag fossil. But the
relative proportions in which they occur by no means agree
with that in which our seas produce them. On the contrary,
in general those which are most common in the sea, appear
to be rarest there, while those which are found at Dalmuir
in the greatest profusion are mostly rare in the sea. For
example, of the Mya truncata, which is one of the commonest
shells in the Firth of Clyde, only one imperfect specimen
has been found at this place, while Fusus Bammus, Lacuna
vincta, Fissurella Noachina, and Astarte minima, none of
which are common shells, together with Natica glaucinoides,
which is a crag fossil, are very common at Dalmuir. Car-
dium edule is extremely scarce, and Mytilus edulis is equally
so, and Ostrea edulis has never been met with, while on the
other hand, Pecten islandicus, and Patella parva, are very
common. From these facts it is evident that the deposit
cannot have taken place while the inhabitants of the Firth of
Clyde were in every way the same as they are at present.

The shells which have been assembled in this confined
spot, and buried in sand in this extraordinary manner,
appear to have been collected from very different situations.
The Nucula minuta, and the Velutina, inhabit deep water ;
the Buccina, and the Astarte, frequent the sands about low
water, in which the Mya truncata and the Cardium edule
bury themselves; while the Mytilus and the Modiola attach
themselves to rocks in deep water, and the Littorina (and
probably the Natica) frequent those rocks which are alter-
nately covered and laid bare by the ebbing and flowing of
the tide.

It is remarkable, and is a circumstance which adds to
the extraordinary nature of this deposit, that the sand in
the immediate neighbourhood of the fossils is quite desti-
tute of any traces of shells. Few of the shells which it

136 Dr. Scouler on some fossil Crustacea [Feb.

contains have been previously found fossil, and therefore it
appears probable, that if not considered as belonging to the
recent period, it must be referred to a very late tertiary era,
at a time when all the low lands on the banks of the Clyde,
at least as far up as Glasgow, have been covered by an arm
of the sea.

Article VI.

Account of some fossil Crustacea which occur in the Coal for-
mation. By John Scouler, F. L. S. Lecturer on Mine-
ralogy to the Royal Dublin Society.

The recent discovery of the remains of fishes and reptiles
in the coal formation of Burdiehouse, rendered it extremely
probable that similar relicts might be detected in the ex-
tensive carboniferous strata of the west of Scotland. With
this expectation, different quarries in the vicinity of Glas-
gow were examined, and although but a short time could
be devoted to the investigation, the research was not alto-
gether unsuccessful. The remains of fishes, fSauroid fishes
of Agassiz) were found in several localities, and in one
place beds of limestone occur, which abound in impres-
sions of ferns and entomostraca.

This limestone is situated about a mile to the east of
Paisley, and was first pointed out to me by Mr. Murray of
the Glasgow Botanic Garden. This rock is distinct from,
and probably reposes on the true carboniferous limestone,
but as only a small patch of it is exposed, the greater part
being covered by the soil, it was impossible to trace its
relations with the subjacent strata. This limestone is of
an extremely compact nature, with little plates of calcareous
spar disseminated through its substance. It readily splits
into flags of variable thickness, which are sometimes made
up of a multitude of extremely thin layers, indicating that
the whole stratum has been formed by the gradual and
tranquil deposition of transported matters. The organic
matters diifer widely from those which we observe in the
carboniferous limestone. I could detect no Productae, nor
any fragments of corals, or stems of crinoid animals, nor in
short, any decidedly massive production. Instead of these,

1835.] which occur in the Coal formation. 137

on splitting up the rock we observe impressions of ferns
of great rarity and beauty, the remains of entomostraca
which are of gigantic size, when compared with the ana-
logous species which still abound in our lakes and pools.
Two species belonging to a new genus were obtained, and
the number might have been greatly increased, had not the
hardness of the rock rendered the extraction of the speci-
mens a difficult task. The following is a short description
of these remains :

1 . Argas testudineus, (Fig. 1 .) The shell is rounded and
deeply emarginate at its anterior extremity, and surrounded
by a thinner margin ; the epidermis is covered with nu-
merous elevated lines. Two ridges extend through the
whole length of the shell, one on each side, their position
being intermediate between the margin and the middle
line. The tail (abdomen) is articulated, but the number
of joints is uncertain, perhaps seven or eight, and it termi-
nates in three appendices (respiratory organs ?) as is the
case in the recent genus Apus. In our specimen these
appendices are of equal length, and have a similar form,
while in the genus Apus, the middle one is the shortest,
and its form is different from that of the others. No ves-
tiges of eyes, antennae or organs of locomotion could be
observed. The length of the specimen from the anterior
margin of the shell to the extremity of the tail is 2$ inches.
Length of the shell li inch. Breadth V5 inch. The shell
has a considerable resemblance both in size and form to
the dorsal shell of some of the fresh water turtles, and
hence the appellation, which we have ventured to give to
the species.

2. Argas tricornis, (Fig. 2.) The shell is elliptical but
truncated anteriorly, and much more depressed than in the
preceding species, and a single ridge runs in the direction
of the middle line. At the anterior extremity of the shell
there are three acute triangular processes, one at each
angle of the shell and one in the middle. Two grooved
lines extend around the circumference of the shell," the one
internal, separating the margin or thin portion from the
rest of the shell, and the other line external, dividing the
margin into two distinct parts. The posterior extremity of
the shell is very indistinct, and the number of joints in the

138 Dr. Scouler on some fossil Crustacea [Feb.

tail could not be ascertained. Length of the specimen
4J inches. Length of the shell 3 inches. Breadth 1J inch.
Length of the tail about lj inch.

This specimen as will be seen by an inspection of the
figure is greatly distorted, the shell has been curved, and
the tail or abdomen almost separated from the body. The
species is, however, completely distinct from the preceding.
The three processes at the anterior extremity of the shell,
and the single ridge running along its middle, are suffi-
cient to distinguish it.

That these animals were crustaceous and belonged to the
division entomostraca, is sufficiently apparent from a mere
inspection of the figures. That they do not belong to any
genus at present existing, may also be admitted. It is true,
that the characters not only of the genus, but also of the
higher groups of crustaceous animals, are chiefly taken
from the arrangement and number of masticatory organs,
feet and antennae, and that all these parts are wanting in
our specimens. Still we have sufficient data for distin-
guishing them from all the genera hitherto described.

In the Limuli the tail consists of a single ensiform appen-
dix, and the shell is divided into two distinct sections,
characters which the fossil species do not possess. Our
fossil species belong to Latreille's class of Branchiopodes
which comprehends the genera Apus, Cyclops, &c, but as
these genera are distinguished by the number of eyes, we
cannot apply these characters to the fossils where every
vestige of such parts is lost. Our specimens are, however,
nearly allied to the two genera which have been mentioned.
They differ from Cyclops, in having three caudal appendices,
while in that species there are but two. In the fossil genus
the shell consists of a single piece, while that of Cyclops is
composed of several sections. In the genus Apus the
middle caudal appendix is much shorter than the lateral
ones, and of a different form, while in the fossil the three
setae are all firm, and the skull has also a different form in
the two genera. We may, therefore, consider these ento-
mostraca, as constituting a new genus, which we have
named Argas, in conformity with the terms, Cyclops,
Monoculus, and Polyphemus.

Entomostraca have hitherto been considered of rare oc-

1835.] whith occur in the Coal formation. 139

currence in a fossil state. In the work of Desmarest on
fossil Crustacea, only two species are described, the Limulus
Walchii found in the bituminous limestone of Solenhofen
and Pappenheim, and the Cypris faba abounding in the
tertiary limestone of several places in France. To these
may be added another species of Cypris found in the Weal-
den rocks of England and figured by Mr. Mantel. They
appear to be more frequent in the carboniferous strata than
is generally suspected, as in addition to the two species
described in this paper, I have described and figured a
much more gigantic specimen (belonging to a different
genus) which was found near Bathgate. # The species to
which I have alluded was at least a foot in length, and the
specimen described measured nine inches, although a con-
siderable part of the posterior extremity was wanting.

The animals of the family entomostraca are cheifly inhabi-
tants of fresh water, although several species are found in
saline marshes and on our shores. With the exception of
the Limuli they are in general extremely minute, and can
only be studied by the aid of the microscope. They abound
in every pool, and may be collected in hundreds. Many of
them are parasitic, and suck the juices of tadpoles and
fishes ; while others swim freely about. The natural his-
tory of these animals is very remarkable on account of the
numerous metamorphoses which they undergo, so that dur-
ing different stages of developement they have but little
resemblance to the mature individuals. They often change
their skin, and at each change can re-produce any organs
they may have lost, and a single fecundation suffices for
the females for several generations.

If we omit the consideration of magnitude, there appears
to be a striking analogy between the vegetable and animal
inhabitants of our pools and lakes, and those of the coal
formation. The little equiseta seldom attaining to the
height of two feet, are the representatives of the ancient
calamites whose height exceeded 15 feet ; and the diminu-
tive ferns and mosses may be compared with the arborescent
ferns and lycopodiae of the coal, while the little entomos-
traca of our lakes are similar in structure, though far

* Edinburgh Journal of Natural and Geographical Science, vol. iii. p. 352.

140 Dr. Scouler on some fossil Crustacea [Feb.

inferior in size to the species which formerly existed in the
same places ; and the same remark applies to the fishes.

Besides the remains already described, the examination
of other places afforded different specimens. Although
unsuccessful in the search for the teeth of fishes, others
were more fortunate. Two teeth of Sauroid fishes were
found by my young friends the Masters Brown, in shale
at the sandstone quarry near Woodside. The sandstone is
covered by alternate beds of sandstone, coal, and shale, and
it is in the last named substance that the teeth are found.
Encouraged by the success of the gentlemen I have men-
tioned, I repeatedly examined the shale of this place, but
unsuccessfully, for the only specimen which I procured was
the spine of the fin of some fish resembling the bony spine
of the dorsal and pectoral fins of some Siluri. It was about
4 inches in length. A sauroid tooth was also found in the
neighbourhood of Campsie, and presented to the Ander-
sonian Museum at Glasgow by Mr. Graham.

Remains of fishes also occur in the parish of East Kilbride,
as had long ago been indicated by Ure in his interesting
work. In that parish the upper part of the limestone is
extremely rich in the remains of marine animals, such as
entrochi, ammonites, productae, reteporae, turbinoliae, Sfc. In
one place whose name I do not know, there are a number
of beds of clay and shale resting upon the carboniferous
limestone, which afford a different kind of organic remains.
In this situation we find the remains of fishes, coprolites,
and Crustacea. The coprolites are as distinct as those
figured by Mr. Mantel from specimens found in the chalk,
and are spirally twisted as is the case in those which are
observed in more recent formations.

No teeth were found, but one bone of a fish was procured
which I have communicated to M. Agassiz, whose labours
have so much illustrated this branch of natural history.
Fig. 1. Argas testudineus.

2. Argas tricornis.

3. Coprolite from East Kilbride.

1835.] which occur in the Coal formation.

141

142 Br. R. B. Thomsons Chemical [Feb.

Article VII.

Chemical Analysis of Crucilite, a new form of peroxide of
Iron. By Robert D. Thomson, M. D.
""" -— * vc
Iron is such an important metal, that every particular con-
nected with its natural history must be received with plea-
sure, both by the manufacturer and the man of science. It
is from this consideration that I venture to describe a new
form in which I have met with it occurring native, in com-
bination with its saturating dose of oxygen.

Previous to doing so, however, it may be observed, that
there are four principal states in which the peroxide of iron
has been hitherto found , which it may be proper to enumerate .

1 . Anhydrous peroxide of iron, or anhydrate or specular
iron ore, the primary form of which is a rhombohedron, and
whose composition may be represented by/.

2. Hydrous peroxide of iron, or perhydrate of iron. Its
primary form is a scalene four-sided pyramid, and its sign
/+Aq.

3. Dihydrate of iron, which has not been noticed in mi-
neralogical books, but has been examined by Dr. Thomson.
A massy specimen from his cabinet which I analyzed pos-
sessed a spec. grav. of 4*016, dissolved with some difficulty
in aqua regia, and consisted of

Peroxide of iron - - - - 77*48

Lime 6*41

Silica 6*00

Peroxide of manganese - - 1*50

Water - - 8*50

99*89
Now this is equivalent to

Peroxide of iron 2 atoms
Water - - - 1 atom
and the formula which expresses this composition is 2/
+ Aq.

4. Magnetic iron ore, consisting of 1 atom of protoxide
and 2 atoms peroxide of iron.

During the course of last year, the variety which has
been already alluded to was brought from Ireland by Mr.
Doran, the mineral dealer. It was seated in sandstone, the

1835.] Analysis of Orucilite. 143

crystals being arranged in the form of a St. Andrew's cross.
On measuring the angles at which these crystals crossed
each other, I found them to be of the value of 60° and 120°.
The crystals themselves were oblique four-sided prisms, the
acute angle measuring 59|°, but so near 60° that I have no
hesitation in considering the latter number as expressing
its true size : the obtuse angle measuring nearly 120° by the
common goniometer. From the cruciform disposition of
the crystals, it is proposed to term the mineral wucilite.

Before the blowpipe it behaves like peroxide of iron. The
crystals are red externally, occasioned probably by the par-
tial absorption of carbonic acid, which has converted them
superficially into a similar combination with rust which is
soft and pulverulent. Internally they are black, and pos-
sess the metallic lustre ; streak black shining ; cleavage
parallel to the faces of the crystals ; fracture uneven ; pos-
sesses no action on the magnet ; sp. grav. 3*579, which is
probably below the true density, as the portion with which
this number was determined, was decomposed. 25 gr. of
the crystals reduced to powder were digested in nitric acid,
and a little muriatic acid was added to increase the action
which was slow with the former agent alone ; a small por-
tion of silicious looking matter remained, which was edulco-
rated, and its weight noted. After ignition it assumed a
yellowish colour, and dispersed through it minute scales
of mica could be distinctly detected, and its appearance was
precisely similar to the sandstone in which the crystals
were seated. It was insoluble in boiling acid, and when
fused with carbonate of soda, alumina and silica were sepa-
rated, while some micaceous scales remained undecomposed.
It had obviously, therefore, been mechanically attached to
the mineral, although care had been taken to separate the
crystals as entirely as possible from the native rock.

The liquid which was separated from this insoluble resi-
due was precipitated by ammonia. A copious precipitation
of iron ensued, which, after being well washed with hot
water, was dissolved off the filter with dilute muriatic acid.
The solution was boiled with caustic soda, which threw
down the iron. This precipitate was again dissolved in
acid, and thrown down by caustic ammonia. The superna-
tant liquid was saturated and precipitated by carbonate of

144 Analyses of Books. [Feb.

ammonia; the resulting precipitate affording, with sul-
phuric acid and potash, crystals of alum. The liquid which
passed through the filter from the iron and alumina, afforded
a precipitation on the addition of oxalate of ammonia, and
afterwards magnesia was procured from it by the usual
process. A portion of the iron precipitate was dissolved in
acid, and to the neutral solution, benzoic acid was added,
which threw down the iron. The solution to which some
carbonate of soda was added was evaporated to dryness.
No residue ensued on the addition of water, indicating the
absence of manganese.

The iron precipitate, when dissolved, afforded powerful
indications of the presence of that metal, by prussiate of
potash. In the solid state it was not affected by the mag-
net. The results of the analyses are : —

Peroxide of iron • .81-666

Alumina 6*866

Silicious matter ....... 6-000

Lime 2-000

Magnesia 0-468

Loss, probably water 3*000

100-000
The quantity of mineral which could be afforded for the
purposes of analysis was, however, too small to determine
directly whether water was present as a constituent. The
relative proportion of the ingredients are

Peroxide of iron 5£ atoms
Alumina ... 1 atom
Silica .... 1 atom
but as it is not easy to conceive distinctly how such a com-
bination can exist, I am rather inclined to adopt the opinion
that the alumina and silica are mechanically mixed with
the oxide of iron.

Article VIII.

Traite Experimental de electricite, 8fc. Par M. Becqtjerel.
Tome II. Paris, 1834.

The appearance of this volume cannot but be regarded by every
cultivator of science as a great boon. The author has undertaken to

1835.] BecquereVs Traitt Experimental, fyc. 145

collect, from scattered sources, the numerous experiments which have
recently been performed so abundantly in elucidation of electricity,
and such a laudable enterprize deserves to be encouraged. To the
Englishman, this work cannot be perused without pleasure, because
he will find in it a view of the labours of his countrymen who are
taking the lead in this branch of Science, and who have essentially
contributed to increase to three large volumes what but a few years
ago was usually comprised in a few pages.

The first book of the present volume of Becquerel's works is
devoted to the consideration of Electrical Statics ; the second book
treats of Magnetism, and the third of Electro-dynamics.

1. There is an important question which it is a great object to
determine, in reference to the developement of electrity by friction.
Whether electrical phenomena derive their origin from the modifica-
tions which the ethereal substance supposed to surround the atoms of
matter undergoes, or from an imponderable fluid which exists in the
interstitial spaces of these atoms. Now, although the first be the
most probable of these suppositions, the facts hitherto observed are
insufficient to resolve the question.

Another interesting subject of inquiry is the relation existing
between conductors and non-conductors of electricity, for all the
elements of bodies, when in solution, are provided with the property
of obeying the action of electrical forces. There are no data, how-
ever, by which this question can be determined.

The author describes minutely electroscopes, or those instruments
which are necessary for detecting small quantities of free electricity
in bodies, and electrometers, a contrivance by which an approximation
can be reached of the charge of a machine, or of an electrical battery.
For appreciating the presence of feeble electrical currents, galvano-
meters, or multiplicators, are employed, in the adaptation of which,
M. Colladon has made some useful improvements. Under this head,
several tables of electrical intensities are given, which are of con-
siderable value.

1. The influence of heat upon the disengagement of electricity
forms that part of the science which has been termed thermo-elec-
tricity. Cumming, Sturgeon, and others, have prosecuted the inves-
tigation of this subject with great vigour. It has been observed
that during the conduction of heat through a bar of metal the
electricity is decomposed, and united in a manner analogous to
the propagation of heat through bodies, and that, in a ring of
bismuth or antimony, if one half is cooled, whilst the other is
heated, an electrical current is instantly produced. Sturgeon has
observed some curious facts in reference to this point, but has not
been able to deduce any general conclusion from his experiments,
save that the developements of the currents in the masses of bismuth
and antimony of different forms, of which all the portions are not
endued with the same temperature, are to be attributed to the
crystalline arrangements which the atoms assume, for if a little tin is
added to these metals the thermo-electrical property is lost. Sturgeon
has observed that all metals possess analogous thermo-electric pro-
perties, provided the experiments be made on considerable masses.

When the ring is constituted of different metals, or when a plate
vol. i. l

146 Analyses of Boohs. [Feb.

of copper is soldered to the extremities of a bismuth or antimony
cylinder, if heat be applied to one of the solderings, an electric
current is established which proceeds from the bismuth to the copper,
or from the copper to the antimony, according to the apparatus
employed. When circuits are formed with wires of different metals,
and the temperature of one of the solderings is elevated successively,
currents are produced which indicate an arrangement of the metals
according to have thermo-electric properties to be bismuth, platinum,
lead, tin, copper, gold, silver, zinc, iron, and antimony, which is
analogous to the order of their specific heats. In most of the metallic
circuits the intensity of the current is in proportion to the tempera-
ture up to 40° at least.

Some minerals exhibit thermo-electrical properties. In the tour-
maline these may be excited by slow heating and cooling, or by rapid
heating aud cooling. These vary, according to Becquerel, however,
in proportion to the size of the crystals, as the smallest tourmalines
assume a very strong polarity by feeble changes of temperature,
while Mr. Forbes has concluded from his experiments, that the size
of the section of the tourmaline employed has so much influence that
where the difference is considerable the largest crystal always is most
powerful. A crystal 1 \ inch in length possessed an intensity of 45°.
When broken at \ of its length, the two portions being heated and again
subjected to experiment, the largest portion indicated a deviation of 47°
and the smallest 43°. Mr. Forbes conceives that we may infer from
analogy that the intensity increases with the diameter of the tourmaline,
but that we are still ignorant if the length of the crystal has any in-
fluence on the electrical properties. Canton, Brard, and Haiiy, have
observed similar properties in other minerals, and Sir David Brewster
has announced them in above 35 bodies, consisting of minerals and
salts. He employed for detecting the pyro-electricity small portions
of the internal membrane of the arundo phragmites, which, when
dry, are extremely light, and adhere to the crystal which has been
heated to the number of 1, 2, and 3. Becquerel considers this test
insufficient, and affirms that the only criterion by which we can
decide upon electrical influence is, first, by the attraction of light
bodies presented to the electricity, and second, their repulsion suc-
ceeding the contact.

Heat diminishes the electrical conduction of metals, while it in-
creases this property in glass, gumlac, and other bad conductors, but
in what way has not been clearly made out.

2. The author enters into the consideration of the electricity
produced by chemical action, as when one body combines with another,
the substance acting the part of the acid becomes positively electrical,
while the alkali is negative; when one solution acts upon another;
when metals react upon acids or saline solutions ; when two different
metals react upon one or more liquids, for instance, if a plate of copper
and one of zinc, communicating each with one of the ends of the wire
of a multiplier, be immersed in a solution of sulphate of zinc, the copper
becomes positive and the zinc negative. 3. A review is then taken
of the experiments of Pouillet, in reference to the developement of
of electricity in combustion. Charcoal, when burned, was found, by
that experimenter, to emit positive electricity in the carbonic acid,

1835.] BecquereTs Traitt Experimental, Sfc. 147

negative in the charcoal, and the same effect was exhibited in the
combination of hydrogen with oxygen, but a negative result was
observed in the flame occasioned in the latter union. Becquerel
shews, however, that this subject requires further elucidation.
Water exhibits no sign of electricity when evaporation commences ;
but when it contains strontian or other bases, the vessel holding the
solution becomes positive, and the vapour of the water negative.

A source of electricity analogous to that of chemical action is the
decomposition of oxygenated water, or peroxide of hydrogen, a sub-
stance discovered by M. Thenard. All the metals, with the exception
of iron, tin, antimony and tellurium, tend to induce the separation of
the elements, and the phenomena dependent upon the contact of the
metals, and the peroxide proceed from its decomposition and from the
oxidation of the metal. When an oxide is brought in contact with
the peroxide, for example oxide of silver, two phenomena occur,
which give origin each to contrary currents which tend to destroy
each other.

4. With regard to the electrical effects produced in capillary action,
it appears that when muriatic acid acts upon spongy platinum, the
latter is at first positive and then negative immediately after. The
reverse occurs with nitric acid. It is obvious that acid is at first
absorbed and gives rise to heat, which occasions thermo-electric
effects ; but the elevation of temperature is not the only cause of the
phenomenon, for if the platinum is removed in the case of the nitric
acid, although a new immersion produces no effect, by heating and
re- immersion in the acid, the current proceeds from the acid to the
spongy platinum, and continues in this direction until the tempera-
ture be equalized in all parts. The direction of the current is the
same as that of a secondary current produced by concentrated acid.
Hence, the first current proceeded from the action of the acid and
platinum, but we are ignorant if it proceeds from a slight alteration
which the platinum may experience from contact with the acid.

5. Electricity may be elicited from all bodies if properly isolated
by pressure. Five substances thus pressed acquire opposite states.
All vitreous crystallized substances such as sulphate of lime, fluor,
spar, &c, when pressed on a disk of cork are electrified positively ;
while fruits such as the orange, under the same circumstances com-
municate to the cork an excess of electricity.

The disengagement of electricty by pressure is modified by several
causes, as the conductibility of bodies and heat. The author des-
cribes minutely an apparatus for determining the intensity of the
electricity developed by pressure, with which numerous trials
have been made on different bodies. The result of these shew that
the electrical intensity is proportional to the pressure, that is to say,
that if the pressure is doubled the intensity is likewise double ; at
least this law holds good as far as a pressure of 10 Kilogrammes
(22 lbs. loz. ldr.)

In connexion with the effect of pressure, cleavage is noticed.
When a plate of mica is rapidly cleaved in a dusk place, a feeble
phosphoric light is observed. On examination each of the separated
porti ons is found to possess an excess of opposite electricities.

l2

148 Analyses of Boohs. [Feb.

6. Two opinions have been broached to explain the effect of elec-
tricity by friction, viz : that it is derived from the adaptation of the
asperities of the surfaces rubbed upen each other, or from the reci-
procal action of the atoms of bodies upon each other. In favour of
the first opinion it is argued that the electrical excitement is great
in proportion to the roughness of the bodies subjected to friction j and
in support of the second the fact is brought forward, that if two
plates of glass or marble are slid upon each other so as perfectly to
cover each other's surfaces, they adhere powerfully to each other
independently of atmospheric pressure, for the same result occurs in
a vacuum. The author has performed a number of experiments for
the purpose of settling this question, from which it appears that the
disengagement of electricity seems to depend on the state of the divi-
sion of the parts of bodies and of the rapidity of friction, and that the
body whose parts undergo the most displacement has a tendency to
produce negative electricty.

The causes which determine the disengagement of electricity in
non- conductors are difficult of appreciation, but the state of their
surfaces has a greater influence upon the nature of the electricity,
than in the metals. Delarive conceived that all the metals when
they are rubbed with wood, the hand, or cork, &c, become nega-
tively electrical. Haiiy has given the name Disthene to a crystal-
lized mineral, whose surfaces have such an influence upon the nature
of the electricity disengaged in the friction of bad conductors, that
positive electricity is exhibited on certain faces, and negative on
others, by the same friction, without any apparent distinction be-
tween them.

Friction in a great number of cases may give origin to chemical
re-action, and electrical effects of chemical origin, have been some-
times attributed to purely physical causes. Becquerel is inclined to
conclude, however, that although chemical action is the most influen-
tial agent in the production of electricity, yet, that in the present
state of the science, it is not proper to abandon the theory of Volta,
in regard to developement by contact. Faraday considers contact to
have no influence.

7» Ampere was the first person who endeavoured to produce
electrical currents by the influence of other currents, but he merely
broached the fact, while Faraday following it out, has formed on it
an important branch of electricity. To the power which electrical
currents possess of exciting electricity, he has applied the term
induction, the induced current, occasioned by the action of the in-
ducing current being directed in a contrary direction. He has fully
confirmed the idea of Ampere, that magnets may be considered as
formed of electrical currents, turning round their molocules in a
direction perpendicular to their axis.

The author, after considering the sources of electricity of which
we have given an outline, proceeds to lay down the laws which
regulate its action.

He explains the important law demonstrated by Coulomb, that the
particles of electricity repel each other inversely as the square of the
distance. Coulomb has shewn that the loss of electricity .in the

1835.] BecquereVs Traite Experimental, Sfc. 149

atmosphere is always proportional to the electrical density ; and it
follows, from the experiments of Lord Stanhope, that the density of
the electricity of electrical atmospheres diminishes inversely as the
square of the distance from the excited body. But, as the demon-
stration of Coulomb's law has been very clearly stated by Dr. Thom-
son in his work on electricity, which, as it contains a full and accurate
description of electrical apparatus, and of most subjects contained in
the remainder of Becquerel's book relating to electricity, we shall beg
leave to refer to, as being more easily understood by the English
reader, and proceed to the section on

II. Magnetism. — After treating of the general properties of
magnetic needles, Becquerel proceeds to consider the earth's action
upon magnets. He describes very particularly Pouillet's compass
for determining the declination, and then brings forward some of the
results obtained by its means. The determination of the resultant
of the magnetic force of the globe is a point of importance, which is
measured by the number of oscillations of the needle occurring in a
given time, the needle acting in relation to the terrestrial magnetic
force, as the pendulum in connexion with gravity. Coulomb has
proved that in reference to the magnetic momentum, the number
19 17*76 represents the force of torsion, which would be necessary to
maintain the magnetic needle at 90°. The forces of torsion for the
deviation of a small number of degrees being proportional to the
angles or their signs, we have
force of torsion = mj fi ^ sin fa j = then force rf

sin. 90°
torsion 19l7"76. He found also that the momentum of needles is
nearly as the squares of the length of the threads of suspension.

2. The force of magnetic attraction and repulsion is inversely as
the square of the distance.

3. The author then proceeds to explain the method of forming
magnets, and describes particularly the application of Gilbert's dis-
covery by Scoresby, by which the magnetic influence can be imparted
to bars of iron without the aid of magnetized bodies. Two bars of
steel are taken, 30 inches in length, with two other plate bars of
steel 8 inches long and half an inch broad, and a long bar of iron,
all of them destitute of magnetic power.

The large bar of iron is first struck in a vertical position, and then
placed, without changing its direction, upon the steel bars which
have also been struck. They are then struck upon each other.
Each of the small bars, suspended vertically to the summit one of
the large steel bars, is successively struck, and in a few minutes they
acquire a considerable magnetic power. Two more of the small bars
united by two small iron parallepepids are rubbed with the four bars,
and are then replaced by two others, and these again by the two last.
Each pair of bars being then treated for a certain space, and being
changed after exposure to friction for a minute, is found completely
saturated with magnetic fluid. This method of preparing magnets
is not only more simple than those of the double touch of Mitchell
and Canton, and of successive contact of Duhamel and Alpinus, but
it increases considerably the magnetic intensity of the bar.

150 Analyses of Books. [Feb.

4. Kupffer has shewn, in regard to the effect of terrestrial mag-
netism upon bars not thoroughly magnetized, that a vertical magnetic
bar has more force when the north pole is directed downward than
in the opposite direction.

5. Quetelet has found that a single friction is sufficient to reverse
the poles of a magnet, and place the bar in a contrary magnetic
state, and that the influence which tends to bring the poles to their
primary state is the most powerful, although, after a certain number
of reversions this tendency diminishes.

6. Magnetic needles which are not too short possess directing
powers with an equal diameter proportional to their lengths, provided
their transverse section be always the same. It results from Cou-
lomb's experiments, that ceteris paribus needles should possess no
greater thickness than is necessary to prevent them from bending.

7. Mr. Barlow has succeeded in determining the law which
regulates the action of iron upon magnetic needles as on board of
ship, viz. : the tangents of deviation are proportional to the cubes of
the diameters, or as the power | of the surfaces, whatever be the
solid contents. The magnetic force being as the surface, and the
tangent of deviation | of the surface, it follows that the square of the
tangent of deviation varies directly as the cube of the force, or the
tangent of deviation varies directly as the power £ of the force.

8. The experiments of Haldat tend to shew that in untwisting an
iron wire which has been magnetized by torsion, its polarity is
removed ; and Nobili has almost proved that magnetism increases
more in proportion to the degree of tempering than to the mass of
the magnetic body.

9. Newton, in his optics, has stated that iron raised to a red heat
is not magnetic, while Kircher has made an exactly opposite remark.

Barlow found the action of iron raised to a blood red heat very
" intense, but extinct at a white heat ; between a red and white heat
he observed that the action increases in proportion as the bar is raised
above the needle, while at a low temperature the action of a bar of
iron in the same circumstances goes on always diminishing. He
heated bars of copper to an intense temperature, and on approachiug
the needle could detect no action. Hence, the heat does not act
independent of the iron. He supposes that during the cooling of
the bars the extremities where the cooling is most rapid become
magnetic before the rest of the metal, giving rise to a complex action,
but admits that this explanation is not sufficiently satisfactory.
Coulomb obtained similar results ; and Kupffer has demonstrated
that the diurnal variations do not contribute to diminish the magnetic
influence of the needle, but that the magnetic force of soft iron
increases with the heat. Mr. Christie found that between the
limits of 112" and 212" an increase of temperature produced an
increase of force in the magnetic power of iron, which seems to
argue against the idea that the action of the iron upon the needle
proceeds from the polarity which is communicated to it by the earth.
10. Coulomb was the first who pointed out the nicest method of
ascertaining the presence of magnetism in all bodies in nature,

1835.] BecquereVs Traite Experimental, Sfc. 151

by suspending them (after being cylindrically formed) by means of
a thread, applying a needle, and judging of the magnetic force by
the number and rapidity of the oscillations, and he extended this
method to detecting small quantities of iron disseminated through
greater masses of other metals. Biot employed it likewise to detect
iron in minerals, as for instance, in two different species of mica, one
from Siberia and the other from Zinwald, in Bohemia. The former
executed 7 oscillations in 55 seconds, the latter 12 in the same time.
The magnetic forces of each were as the squares of these numbers, or
49 to 144 ; considering these forces as proportional to the quantity
of oxide of iron., the Zinwald mica should contain 20 per cent, of the
oxide, and the other 6*8, which corresponds with the result of
analysis. Haiiy endeavoured to detect still smaller quantities of
iron by a modification of this plan. By these means it has been
ascertained that all bodies placed near very powerful magnets mani-
fest feeble magnetic properties attributable to small quantities of iron
which have not been detected by art. Arago has proved further that
all bodies in the neighbourhood of a needle which oscillates, produce
in it an action, the effect of which is to diminish the extent of the
oscillations without diminishing their number. He found also that
by causing a rotatory motion in a plate of copper, placed under a
magnetic needle, that the needle was driven from the magnetic
meridian at the commencement of the rotation, increasing in force
proportionally to the rapidity. Prevost and Colladon deduced from
their experiments that the angles of deviation, and not their signs,
increase in proportion to the rapidity that the signs of the angles of
deviation increase inversely with the power 2j of the distance.

Babbage and Herschel have announced that the law is not con-
stant, and that it varies between the square aud the cube of the
distance.

Barlow observed, that whatever be the direction of the axis of
rotation, if the movement of the rotating body is directed towards
the needle, the north pole of the latter is attracted ; if the contrary,
then the extremity is repulsed. If the needle be carried round the
rotating body parallel to the axis, it has a tendency to arrange itself
at right angles with it.

1 1. Electricity and magnetism although they agree in most respects
differ apparently in this, that electricity penetrates into all substances,
while magnetism only enters three bodies in a state of rest, viz. iron,
cobalt and nickel. Poisson has endeavoured to reconcile this and the
other facts with which we are acquainted in reference to this prin-
ciple, by his theory. He conceives that we may represent a mag-
netic body, as a collection of magnetic parcels separated by spaces
inaccessible to magnetism. The relation of the sum of all these par-
cels to the entire volume of the body which may be considered its
density, in relation to magnetism, will be a fraction which will ap-
proach unity more or less in bodies of a different nature, and which
ought to be given for each body in particular. He attributes all the
magnetic phenomena to two imponderable fluids, influenced by
general laws of equilibrium and motion, and which may exercise upon
bodies, in consequence of the reciprocal action of their particles, pres-

1 52 A nalyses.of Boohs. [Feb .

sure which may be measured. The law of their attraction and repul-
sion is inversely as the square of the distance. His theory of the
magnetic phenomena of rotation has been shaken by the discoveries
of Faraday.

III. Electro-dynamics. 1. To Oersted we are indebted for the
foundation of this branch of electricity. He demonstrated the action
of electric currents upon the magnet, while Biot and Savart prose-
cuting the subject discovered the law which regulates this action at
a distance, viz. : that the electro-dynamic force increases inversely as
the simple distance. M. Savary applying the formulae of Ampere
to the experiments of Biot and Savart, has found that the total
action of the wire was reciprocally proportional to the simple distance.
M. Colladon first observed the action of the Leyden phial upon the
needle. With a phial two feet square charged as strongly as possible,
the deviation of the needle was 32 °. Faraday has demonstrated fur-
ther, that a continuous deviation of the magnetic needle in the mul-
tiplier may be obtained with the common electrical machine, pro-
vided time be allowed to enable the action to be produced, by causing
the electricity to pass along imperfect conductors.

2. But one of the most important consequences from the discovery
of the action of the electric fluid upon the magnet was the observa-
tion of M. Arago, that the same current developed the magnetic pro-
perty in plates of iron or steel which did not previously possess it, and
that to communicate magnetism to needles deprived of it, it is ne-
cessary to place them in a direction perpendicular to the forming wire,
or if a strong degree of magnetic influence is required, it is necessary
to introduce them into a helix, and make the current pass across the
wire. Savary has observed, that the magnetic influence is produced
inversely as the distance of the needle from the wire, and that a given
discharge produces always magnetic power, so much the more intense
as the length of the wire is greater in relation to its diameter ; and
that equal fragments of the same needle, in the interior of a helix,
were always equally magnetized, Arago having previously shewn,
that similar needles are equally magnetized. He considers that all
the phenomena which he has observed, may be deduced from the
hypothesis, which ascribes the dependence not only of the intensity,
but the magnetic influence to laws, according to which, the minute
motions are extinguished in the wire, in the medium which surrounds
it, and in the substance which receives and preserves the magnetic
power. Moll has shewn that the force of the communication of the
magnetic power, depends on the rapidity of the current. Lipkins
and Quetelet have proved that very powerful magnetic effects may
be produced with voltaic elements on a confined surface, if the che-
mical action is energetic, and that on varying the dimensions of the
voltaic elements and the portions of iron, the energy of the effects
depends less on the size of the first than on that of the second.

In reference to the power of retention of magnetism on soft iron,
Mr. Watkins found that in applying a current across a helix to a piece
of iron, a weight of 120 pounds was sustained, but on interrupting
the current, 56 pounds only could be supported. He has concluded
that the power of suspension of electric magnets depends on a com-

1835.] BecquereVs Traite Experimental, Sfc. 153

plex induction, and that all magnetic phenomena, belonging to this
class of effects, derived their origin from this induction.

3. The last chapter in the present volume is devoted to a detail
of experiments, in relation to the production of electrical currents,
by the action of other currents, a branch of science which has been
entirely formed by Dr. Faraday, to which he has given the name,
electro voltaic induction. The experiment which laid the founda-
tion of these important observations was, that of employing two
cylinders of wood, rolling over them, in a spiral form, 12 spirals
formed each of 203 feet of copper wire, ^th of an inch in diameter,
and covered with silk, and causing one to communicate with the multi-
plier and the other with a pile of 100 pairs of double copper plates, of
4 inches square, and well charged. At the moment of contact the
needle underwent a deviation, then after some oscillations it returned
to its position of equilibrium, and was deverted again when the action
of the pile was interrupted, but in a contrary way ; the force of the
inducing current being, however, greater at the moment of contact
than when it is interrupted.

But not only are electrical currents induced by currents of elec-
tricity, but likewise, electricity is induced by the agency of magnets.
This is proved in the case of common magnets, by attaching to the
multiplier all the elementary spirals, introducing into its axis a
cylinder of soft iron, and then adjusting two magnetized bars, each
24 inches in length, so that on one side, their opposite poles being
brought in contact, the two others may touch equally with the two
ends of the iron cylinder, in order to transform it for the time into
a magnet. At the moment of contact the needle deviates, then
assumes its equilibrium, and deviates in another manner when the
bars are withdrawn.

Dr. Faraday has applied himself to the investigation of the new
electrical state of the substance during induction. He has named
this state electro-tonic, and considers it as a state of tension equivalent
to an electric current, at least equal to the current which is produced
when an induction takes place or when it is suppressed. He conceives
that when electric currents pass across bodies, the latter become
electro-tonic, and give rise to electro-chemical decompositions, the
current acting upon a portion of the electricity of the neighbouring
body in such a way as to drive off a portion and attract the remainder,
as happens in the disengagement of electricity by influence. In re-
ference to the application of the magnetic induction to the explanation
of the magnetic phenomena observed by M. Arago, it has been found
by Faraday that the electric current which is excited in a metal
rotating near a magnet, depends entirely as to its direction on the
relation of the position of the metal to the resultant of magnetic
action, or with the magnetic curves.

M. M. Nobili and Antinori have suggested a method for discovering
the distribution of currents, produced by the influence of magnets of
rotating disks. This is by applying the two extremities of the wire
of a multiplier, terminated by two thick conical points upon the
rotating disk. They have likewise exhibited the analogy of Arago
and Faraday's researches.

154 Analyses of Books. [Feb.

Faraday has, however, obtained the same results from terrestrial
magnetism as from magnets. He made a helix communicate with a
multiplier and a cylinder of soft iron which possessed no magnetic
power. This cylinder was placed in the helix, which had been
directed previously according to the magnetic inclination. The iron
becoming magnetic, induction was exhibited as if a magnet had been
actually employed. And from his experiments it appears impossible
that a metallic sphere can rotate without producing electrical currents
in its interior, in a planfc perpendicular to the plane of revolution,
provided that the axis of rotation does not coincide with the direction
of the magnetic inclination. He suggests that in the action of steam
engines their metallic mechanism may produce accidental electro-
magnetic combinations, which may occasion effects hitherto unob-
served. He thinks likewise that admitting the earth to produce
currents in her own mass during its rotation, by the electro-magnetic
induction, these currents at the surface will be directed into the parts
which approach the plane of the equator in a contrary way from
those which would take place towards the poles. Hence, if we could
examine the subject minutely, we might find negative electricity at
the equator, and positive electricity at the two poles.

He has advanced, but with diffidence, an opinion that the aurora
borealis may be derived from a discharge of electricity driven towards
the poles of the earth, from whence it might be forced, by natural
and particular means, to return to the equatorial regions above the
surface of the earth. He has observed that the current excited in a
copper wire is more powerful than that which is produced by the
same magnet in an iron wire ; and the metals whose properties he
has examined in reference to this may be arranged in the following
order : copper, zinc, iron, tin, and lead, which corresponds nearly with
their electric conducting power, and with what Babbage, Herschel,
and Harris have found in their experiments on magnetic rotation.
Faraday arranges the metals in three classes, in reference to their
connexion with the magnet ; 1, those which are affected when at
rest, as iron, nickel, cobalt; 2, conductors of electricity influenced
during rotation; 3, those which are perfectly indifferent to the
magnet, whether they are at rest or in motion.

It remains now to enquire into the nature of the currents of in-
duction. A striking difference exists between the currents produced
by magnetic influence in the helices and the hydro-electric currents,
and a remarkable difference between these currents and those derived
from an origin connected with heat. This difference has been gene-
rally ascribed to the greater tension of the hydro- electric piles than in
the thermo-electric piles.

According to the result of an ingenious experiment of M. Peltier,
currents of induction are formed by the union of several equal cur-
rents, for he obtained by the action of live helices, superimposed on
each other, a deviation four times greater than was obtained by a
multiplier with one turn ; it was double with that of ten turns, and
produced no effect upon one formed with a wire of 2000.

In uniting all the helices, so as to produce a single circuit, no effect
was produced on the multiplier with a single turn, nor on one with

1835.] BecquereVs Traitt Experimental, Sfc. 155

ten, if the diameter of the wire was small ; but the action was dis-
tinct when the wire possessed a certain thickness. The effect of the
multiplier of 2000 turns was tribled. Similar phenomena occur in
thermo-electricity.

To explain these facts, and others which have been observed in
reference to the interesting subject of induction, it has been con-
ceived that every electric current consists of the combination of two
currents, one positive and the other negative.

Article IX.

SCIENTIFIC INTELLIGENCE.

I, — New Expeditions of Discovery.
London University, Evening Meeting, 14th January.

Captain Maconochie opened the chair, to which he has recently
been appointed in this University, by delivering a lecture on the expe-
ditions of discovery, which are now in progress in South Africa and in
British Guayana. The subject is one of great interest, and attracted
much attention. The lecturer began by mentioning some facts with
regard to the Royal Geographical Society, under whose auspices the
travellers have started. This society he observed, was established in
1830, and notwithstanding the political state of distraction which
existed in the country at that period, was able in the course of a few
weeks to collect no less a sum than £ 7000, for the purposes of patro-
nising geographical research. It has already done a great deal. No
less than 4 volumes of transactions have been published by it, which
are full of important details. Through it the account of Lander's suc-
cessful descent of the Quorra, and of his discovery of the melancholy
end of poor Park, was first communicated to the public. The only
acknowledged report of Ross' recent perilous voyage was given by
this society, and the same observation applies to the enterprising
expedition of Lieut. Burnes and Dr. Gerrard across the wilds of Asia.
The lecturer read a passage from an address of Lieut. Burnes' des-
cription of his feelings at the intelligence, which he received during
his perilous journey, of the establishment of this society. He was
then with his companion at Bokhara, where a packet of newspapers
overtook him conveying the information. New vigour was immedi-
ately instilled into their adventurous spirits; as they were now
aware that there were some at home who sympathized with them,
and who, if they should perish on their route, would nobly rescue
their names from oblivion.

To confer additional importance on the influence of this society,
his Majesty has been graciously pleased to give his countenance to
its labours, and has generously granted an annual premium of 50
guineas to be bestowed on contributors to geographical discovery.
Premiums have been already conferred on Lander, Ross, and Burnes.

The society have it now in contemplation to patronise adventurers
in the discovery of the unknown regions of Africa and South America.
In the former country, with the exception of a few Portuguese

156 Scientific Intelligence. [Feb.

settlements on the east coast, visited by Captain Owen, the Cape
Colony and the course of the Congo for about 280 miles, the whole
of Africa, south of the Line is totally unknown to us. M. Douville
it is true, has lately published 3 volumes, and a quarto book of
drawings accompanied by a map, descriptive of a journey into the
interior, from Benguela on the west coast, where he lays down lakes,
rivers, and towns in abundance, as far as about 20° E. L., and 3° or
4° S. L ., but it is generally believed, that the whole is an imposition.
Captain Maconochie is, however, more charitable, and conceives that
the descriptions may be founded on fact, as Douville, who was in
London is an intelligent man, and appears to have visited the coun-
try, in connexion with the slave trade. On the east coast there
seem to be two favourable modes of ingress into the interior of this
terra incognita. One of these is by a river a little to the south of
the equator, termed in our maps Rio Grande, which is doubtless of
great size, and if followed, would lead the traveller far into the
interior.

The other inviting line of route, is by a river which pours itself
into the ocean a little to the north of Delagoa Bay, which is conjec-
tured to be the continuation of the large stream, observed by Camp-
bell in his visit to Kurrachane, a town situated in the interior of the
country. It is from this point that the new expedition is to start.
What adds to our interest, in reference to this portion of Africa, is
the fact of the native tribes in the interior, being well versed in some
of the most useful arts of life. The missionary Campbell, was the
first who penetrated to Kurrachane, near the 24° of latitude, but his
route was speedily followed by some of the Cape traders, who not-
withstanding the great land carriage of 1200 or 1400 miles, traded
with one nation alone to the amount of £ 1600. At Kurrachane,
we are told, iron is smelted and manufactured into knives, and
agricultural implements, of such superior quality as to be nearly equal
to steel. Cast iron pipes were seen by Captain Owen on the coast,
which were said to be brought from the interior. Agriculture appears
also to have made greater progress than to the southward, for at
Leetakoo, Campbell observed no stone-walls surrounding the corn
fields, while at Mashow and to the northward, these fences were
general, and in appearance would have been creditable even to
Britain itself.

The author of the treatise on maritime discovery, in Lardner's
Cyclopaedia, having placed these facts in a strong point of view,
before the Geographical Society, suggested the propriety of sending
an expedition from Delagoa Bay to Kurrachane. The society imme-
diately entered keenly into this project, which was steadily pursued
for 18 months, when pecuniary means were procured for carrying it
into execution. Captain James Alexander volunteered to take
charge of it ; and sailed in September last. News have been received
of his arrival at the Gambia, where he touched in his way, and by
the present time, it is expected he may have reached the Cape. His
instructions are to land on the north of the river at Delagoa bay, and
not to endeavour to navigate it, but to cross it, and follow the line
of the greatest population, to enquire into the manners and customs,
the state of the people in reference to the arts, and to ascertain, what

1835.] Scientific Intelligence. 157

would be the probable consequences of instituting a trade with them,
as the existence of the river leading into the interior promises great
facilities, should the chances of a successful commercial intercourse
be deemed probable. Should he succeed in reaching Kurrachane,
he has then performed all that the society have in view, but should
his health enable him to penetrate* farther, he may endeavour to
reach some of the Portuguese settlements, and will then have con-
tributed greatly to our knowledge of this portion of Africa.

With regard to the geography of the country to the northward of
Delagoa Bay, Captain Maconochie stated, that from the information
which he had collected from an envoy, whom the Imaum of Muscat,
has sent to this country for commercial purposes, it appears that
there is a large lake or inland sea, termed Marrabee, in the interior,
which extends as far north as the latitude of Mombaza, and is so broad,
that a row boat requires ten days to cross it. This Arab had been on
its banks, whither he had gone in company with caravans trading be-
tween the coast and that neighbourhood. The natives by peculiar
ceremonies are in the habit of receiving strangers into friendship, and
when they have once done so, they continue to afford them protec-
tion. The Muscat-man has undergone those ceremonies, and has
volunteered to accompany any English traveller, and ensures perfect
safety, as far as regards the natives. His account of the interior
agrees withjthat of Captain Boutchier who was wrecked on this coast.
He further states, that a traveller might accompany the natives in
their pilgrimage to Mecca, by Suakem, and would have protection
extended to them.

The new expedition into Guyana has for its object the examination
of the tract of high land which forms the southern boundary of
French Guyana, Surinam and part of Columbia, and divides into two
portions the great Oronoco Island, as it may be termed, for the Oro-
noco has been proved by the travels of Humboldt to communicate by
means of the Cassaquairo, with the Rio Negro, which terminates in
the Amazon. Humboldt penetrated as far as Esmeraldas, but from
this point to the Ocean, as far as regards our knowledge, it may be
said all is barren. Mr. Waterton, it is true, reached the frontiers of
Brazil, but his attention was almost entirely devoted to the study of
zoology, so that he has given little information in reference to the
physical features of the country. This tract is interesting, as having
been the El Dorado of Sir Walter Raleigh, who mistook mica for
gold ore, and as containing his great inland sea and city on its banks,
which continue still to have a place in maps, although they appear to
have no existence in reality beyond the occurrence of slight inunda-
tions. Some French travellers in French Guyana, have recently ob-
served tumuli resembling those of North America, which adds an
interest to the investigation of the habits and manners of the Indians.

The idea of sending this expedition has been entertained for some
time, but it was only lately that funds could be obtained. The
Geographical Society, however, offered to provide £ 500, which was
met by an addition of £ 1000 by the British Government. The in-
dividual intrusted with this expedition is now in the West Indies,
preparing at the proper season to proceed up the Essequibo river, in
prosecution of his journey.

158 Scientific Intelligence. [Feb.

Note by the Editor. — In listening to Captain Maconochie's lec-
ture, (in my report of which, as far as my recollection goes, I have
included every point of importance.) I was rather surprised that
he should have omitted to mention the expedition, which several
months ago, under the direction of Dr. Smith, proceeded into the
interior of South Africa, as from the liberal manner in which prepara-
tions have been made for it, and the well known qualifications of the
conductor, who is an excellent naturalist, there is some reason for
concluding, that the projected expedition of the Geographical Society
will be anticipated. Would it not have been more judicious, if the
Society had contributed their assistance to an expedition so well sup-
plied with the means of investigating both the physical and moral
state of the country ? As the present expedition starts from Delagoa
Bay, it can have no conveniences for carrying instruments for obser-
vation, or geological or botanical specimens, while Dr. Smith, being
supplied with commodious Cape waggons, has ample means of return-
ing with splendid collections of natural history specimens, and it is
certain, that the enlightened members of the Geographical Society
would be the last individuals, who would not say that the objects of
science should occupy a s most prominent place in expeditions of
discovery.

With regard to the expedition suggested by Captain Maconochie
to Lake Marrabee, there seems to be no object in view except that of
geographical discovery, which although very laudable shonld always
be combined with something higher. I conceive that by far the most
desirable route for an expedition of discovery, would be the ascent of
the Bahr al Abiad or true Nile, which would lead into the very centre
of Africa, now known to be the finest and most fertile portion of that
vast continent. If the source of this river were attained, a most in-
teresting tract of country would be investigated, the nature of the
Mountains of the Moon, as they have been poetically designated,
which in all probability give origin to the Nile and Congo, with nu-
merous other rivers, would be ascertained, and the traveller might
then endeavour to make his way to Marrabee, or by the Congo, ac-
cording as circumstances determined him. The origin of one of the
largest rivers in the world, for an account of which we still depend
upon the vague reports communicated to Herodotus, (from whose
statements it appears, that above 300 miles of the course of this river
have never been visited by any modern traveller,) of the savage ex-
peditions would be determined. In selecting individuals to undertake
these . expeditions, however, it would be proper to employ such as
have acquired considerable knowledge of Science, and if intelligence
that such journeys were in contemplation, were more generally dis-
seminated, I am convinced that persons could be procured, possessing
the necessary requisites. Two persons with a servant could accom-
plish a great deal, viz. a Medical man having a knowledge of Geo-
logy and Natural History, and a Navy Officer who would require
to be a draughtsman and a good practical astronomer. Every one
who engages in such enterprises must reconcile his mind to the worst
that can happen, and must not anticipate kind treatment from na-
tives, for although one tribe may afford protection, its very sympathies
may be excited by its inferiority to more savage neighbours.

1835.] Scientific Intelligence. 159

II. — Improvement in the Arts.

Printing in Colours. — It has long been a subject of regret that
notwithstanding the high state of perfection which the arts of print-
ing and engraving have reached, that hitherto attempts at printing
in colours have been attended with complete failures. Mr. G.
Baxter, Wood-engraver, King's Square, Goswell Road, has however,
succeeded in printing in colours from wood, so successfully, that we
consider it proper to call the attention, especially of naturalists, to
the works of this meritorious young artist, who, being master both
of engraving and printing, will be enabled, if properly encouraged,
to make great improvements in this interesting branch of art, which
he may be said to have originated. We have before us a delineation
of Howard's Modifications of Clouds, in which the superiority of the
new style over the common method of colouring is most strikingly
exhibited.

III. — On the native country of Maize (Zea mays.)

Roulin, Humboldt, and Bonpland, have noticed this plant in its
native state, in America, and have hence concluded that it was
originally derived from that country. Michaud, Daru, Gregory,
and Bonafous state, that it was known in Asia Minor before the
discovery of America. Crawford, in his History of the Indian
Archipelago, tells us that maize was cultivated by the inhabitants of
these islands, under the name of djagoung, before the discovery of
America. In the Natural History of China, composed by Li-Chi
Tchin, towards the middle of the sixteenth century, an exact figure
is given of maize, under the title of la-chou-cha ; and Rifaud, in his
u Voyage en Egypte, &c, from 1805 to 1827," discovered this grain
in a subterraneous excavation in a state of remarkably good preserva-
tion. M. Virey, however, refutes these statements, (Journal de
Pharmacie, xx. 571,) by shewing that these authors have mistaken
the holcus sorghum for maize, and that the maize of Rifaud is the
holcus bicolor, a native of Egypt according to Delile. Where maize
occurs in the east their is no proof of its having been carried there
previously to the discovery of America.

Maize, (Zea, mays) therefore sprung from America ; millet, or
couz couz, from Africa ; rice, (oryza sativa,) from Asia ; and
wheat, barley, and oats, from Europe.

IV. — Hydrate of Iron, an antidote for arsenious acid.*

Dr. Bunsen of Gottingen has proposed the hydrate of iron as an
antidote in cases of poisoning by arsenious acid, for he finds that a
solution of the acid is completely precipitated by the hydrous oxide.
He has observed likewise that if the latter body is exposed to a gentle
heat with arsenious acid in very fine powder, an arsenite of iron is
formed. He has ascertained by experiments on dogs that from two
to four drachms of the oxide, mixed with sixteen drops of ammonia,
are sufficient to convert eight or sixteen grains of arsenious acid
into an insoluble arseniate.

* Journal de Pharm. xx.

160

Scientific Intelligence.

[Feb.

V. — New Pharmaceutical Preparations,

Employment of white oxide of lead in tic douloureux. — This
oxide has been employed in France with great success in the painful
affection of the face, known by the name of tic douloureux. A
layer of the following mixture

Ceruss, 1 ounce. White oxide of lead 2 or 4 gr.
is applied to the part affected, to the depth of half a line. The
intensity of the pain speedily subsides, and gradually dissappears. —
Journal de Pharm. xx. 603.

Collyrium of Nitrate of Silver of Dr. Munaret. — Take of
saturated aqueous solution of nitrate of silver iv. gr.

Distilled water, 1 ounce. Laudanum, iii. gtt.

This is very useful in chronic inflammation of the conjunctiva, and
even in the acute inflammation of the globe of the eye. The action
may be assisted by leaching and aperient medicines.

The Boletus Larycis, or white mushroom, is recommended by M.
Andral, in colloquative sweats. He prescribes it to the extent of 48 to
60 gr. made into pills of 8 gr. each, without observing any effect upon
digestion, although it was long supposed to be a drastic purgative.

M. Pouche has found the Cyanuret of gold, useful in siphilis and
scrophula. M. Figuier recommends that in preparing this compound
the chloride of gold should be neutral, that the cyanuret of potash
should not be alkaline, and should be free from formate and car-
bonate of potash. What remains after the calcination of ferro-prus-
siate of potash in close vessels answers very well, when dissolved
and carefully precipitated with the salt of gold, avoiding any excess of
the potash salt. M. Pouche rubs it on the tongue mixed with an
inert powder, such as iris of Florence washed with alcohol in the
proportion of 1 gr. cyanuret of gold to 3 gr. powder of iris. In the
form of pills it may be given in the following : Cyanuret of gold 1 gr.
Extract of daphne mazereum 3 gr. Powder of Mallows q.s. for 5 pills.

For children it may be made up

always begin with -^-th of a grain.

VI. — Register of the fall of
Macfarlane Observato

January
February
March .
April .
May .
June .
July .
August
September
October .
November
December

with chocolate paste. We should

Pain during 1834, kept at the
Glasgow University.

Inches.

3-954
1-368
1-759
0-134
0-762
2-078
1-183
2-523
2-578
1-403
3-007
1-112

21-861

RECORDS

OF

GENERAL SCIENCE.

MARCH, 1835.

Article I.

On Calico- Printing. By Thomas Thomson, M.D., F.R.S.,
L. and E., &c, Regius Professor of Chemistry in the
University of Glasgow.

(continued from p. 19. )

13. White discharge on Madder-Tied.

x<-

>K<

&4>>-<^\

j> > J" <r.. + j <

WAI

%vd

^

When the aluminous mordant already described is printed
on the cloth its basis (alumina) becomes fixed, and ready to
combine with whatever colouring matter may be subjected to
its action . Another mode of applying the same mordant, and
producing patterns with it, is to impregnate the whole cloth
with it, and afterwards to print the figure with a substance

VOL> I.

M

162 Dr. Thomas Thomson on [March.

which has the power of rendering alumina soluble in water.
The cleansing processes to which all cloths impregnated with
mordants are subjected before dyeing, remove that portion
of the alumina which has been rendered soluble, and leave
portions of the cloth in the shape of flowers, crosses, &c,
without any material capable of fixing the dye-stuff. When
the cloth is dyed in the way already described these portions
remain white, or at least become white after the requisite
washing.

The substance which has been found to answer best for
the removal of alumina and peroxide of iron is citric acid.
Some of the advantages of such an acid are obvious. It
does not corrode the cloth, though subjected to a consider-
able degree of heat. It is a fixed acid, with little tendency
to swell or travel to other portions of the mordant than
those with which it is intended to be combined ; and it has
the advantage over other vegetable acids of dissolving away
very completely all the alumina or oxide of iron, so that no
portion of these mordants is retained by the cloth. When
we consider the ease with which this acid is abstracted by
water, from the insoluble citrates, we would, apriore, infer
that it is very little adapted for this purpose of the calico-
printer, which, in fact, it is found to answer better than
any other. But the probability is that water has no such
tendency to abstract it from the soluble citrates, as citrate
of alumina, and citrated peroxide of iron.

The citric acid is often printed before as well as after the
application of the mordant. In the latter case it is generally
assisted by bisulphate of potash, or even sulphuric acid, by
which the more expensive acid is economized.

14. Madder and Logwood.

1835.] Calico- Printing. 163

The cloth is impregnated with the aluminous mordant
which is discharged on the white portions by the method just
described. It is then dyed with madder in the usual way,
only a quantity of logwood is mixed with the madder. This
logwood changes the madder- red to brown, and produces the
colour observable in the accompanying piece of calico.

15. Cochineal Pink.

The cloth in this case also is impregnated with the same
aluminous mordant, and the white portions are discharged
by means of citric acid, in the way described in a former
paragraph. It is then dyed in cochineal, which communi-
cates the beautiful pink observable in this specimen of
cloth.

For this beautiful dye we are indebted to America.
Cochineal is the name given to a small insect which
inhabits the cactus coccinilifera, and three or four other
species of cactus, on which it remains immoveable, deriving
its nourishment from the juices of the plant. It is a native
of Mexico, and had been employed by the natives as a red
dye. When the Spaniards entered that country in 1518, it
drew their attention, and in 1523 Cortes received orders
from the Court of Spain to procure as great a quantity of it
as possible. The earlier Spanish writers describe cochineal
as an insect ; but it came afterwards to be considered as the
seed of a plant ; and this erroneous notion was not fully
cleared away till about the middle of the eighteenth century.

The red principle in cochineal may be extracted by means
of alcohol. It has a fine purple colour, and may be obtained
in small crystals. It melts at 122°, and when heated, is

m 2

164

Dr. Thomas Thomson on

[March.

decomposed without yielding any ammonia, from which we
may conclude that it contains no azote. It dissolves readily
in water and alcohol, but not in ether. Acid gives it a
yellow tinge. Hence the reason why bitartrate of potash
must be added when we wish to dye scarlet with cochineal
alone. If we agitate newly precipitated alumina in an
aqueous solution of cochineal, the colouring matter com-
bines with the alumina, and gives it a fine red colour. The
paint called carmine is alumina impregnated with cochinealin.*

16. Black Ground and White.

The method of fixing the colouring matter in this case is
precisely similar to the two last examples : the sole diffe-
rence lies in the dye-stuff used. The calico is in the first
place impregnated with the aluminous mordant. The mor-
dant is afterwards discharged by means of citric acid from
those parts of the cloth that are to remain white. It is
then dyed to saturation in logwood.

Logwood is the wood of the hematoxylon campeschianum,
a tree which grows to a considerable size in Jamaica, and
on the eastern shore of the Bay of Campeachy. It owes
its dyeing powers to a colouring matter which it contains,
to which the name of hematin has been given. If we digest
the raspings of logwood in warm water, evaporate the
infusion to dryness, dissolve the residue in alcohol, and
distill off the alcohol to a syrup, and set the syrup aside,
crystals of hematin are deposited. They are needles
arranged in sphericles, and having a fine scarlet colour.
Hematin is but little soluble in water ; but it dissolves in

* This is the name given hy chemists to the colouring matter of cochineal.

1835.] Calico-Printing. 165

alcohol and ether. It combines both with acids and with
bases. It has a strong affinity for alumina, and may be
united at the same time with different metallic oxides.

17.

In this calico two engravings are employed. The deep
colour and the white objects are printed at once, by
two copper rollers, in the same machine : the white being
the lemon juice already described, thickened with gum-
senegal. After this another roller applies the ground work
over the whole piece with a solution of iron. The iron
becomes fixed on the cloth every where except where the
acid has been applied, which remains white.

18. Turkey-Red and White Bandanas.

The word bandana has been appropriated to cotton printed
pocket handkerchiefs. By far the most beautiful and the
best known of these are the Turkey-red dyed handkerchiefs,
with white spots, stars, or crosses, such as the specimen
now presented to the reader.

166 Dr. Thomas Thomson on [March.

What is called by the name of the Turkey-red dye has
long been known in the Levant, and in different parts of
Turkey. From that country it made its way to France,
and about fifty years ago it was begun in Glasgow, by a
Mr. Papillon, who established a Turkey-red dye- work
along with Mr. M'Intosh. He made an agreement with
the commissioners and trustees for manufactures in Scot-
land, that the process was to be by them published for the
benefit of the public at the end of a certain term of years.
Accordingly, in the year 1803, the trustees laid a minute
account of the different steps before the public. The pro-
cess has been followed in Glasgow ever since, and many
improvements have been introduced. The method of dis-
charging the colour, as exhibited in the specimen, was
first practised on an extensive scale by Henry Monteath and
Company, at Rutherglen Bridge. It is probable that the
process was discovered by more than one individual about
the same time. I know of at least three claimants ; but
not having the means of determining the priority of any of
them, I think it better to avoid uncertain details.

The method of fixing the Turkey-red dye on cloth is
complicated and tedious. I shall here give a sketch of the
different steps, and explain them so far as they are understood.

(1 .) The cloth is steeped in a weak alkaline ley, to remove
the weaver's dressing. This is technically called the rot-
steep. Four or five pounds of caustic potash are generally
employed for every 100 lbs. of cloth. The temperature of
the solution is from 100° to 120°; the cloth is kept in the
steep for 24 hours and then well washed.

(2.) From 7 to 10 lbs. of carbonate of soda are dissolved
in a sufficient quantity of water to keep the cloth (always
supposed to weigh 100 lbs.) wet. In this solution the cloth
is boiled for some time.

(3.) It is upon the third process that the beauty of the
colour depends more than upon any other. Without it the
dye cannot be produced upon new cloth ; but when old
cotton cloth that has been frequently washed (a cotton shirt
for example) is to be dyed, this process may be omitted
altogether.

A liquor is composed of the following ingredients : —
1 gallon of gallipoli oil

1835.] Calico- Printing. 167

1 J gallon of soft sheep-dung

4 gallons of a solution of carbonate of soda, of the

specific gravity 1*06
1 gallon of solution of pearl ash, of the spec. grav. 1*04.
mixed with a sufficient quantity of cold water to make up
22 gallons. The specific gravity of this liquor should be
from 1-020 to 1-025.

This liquor has a milk white appearance, and is, in fact,
a kind of imperfect soap. It is put into a large wooden, open,
cylindrical vessel called the liquor-tub ; and is kept con-
tinually in motion (to prevent subsidence) by wooden levers,
driven round in it by machinery. This liquor is conveyed by
tin pipes to a kind of trough, in what is called the padding-
machine, where the cloth is thoroughly soaked in it. The
longer the cloth is allowed to remain impregnated with this
liquor the better does it take the dye. Fourteen days is
the least period that this impregnation is allowed to remain.

The sheep dung gives the cloth a green colour, and is
found materially to assist the bleaching process to which it
is afterwards subjected. It is found to increase the rapidity
of the bleaching, especially when the cloth is exposed on
the grass between the different operations.

(4.) In favourable weather the cloth impregnated with
the imperfect soap of No. 3, is spread upon the grass to
dry. But in rainy weather it is dried in the stove.

(5.) The cloth thus dried is a second time impregnated
with the oleaginous liquid of No. 3. It is then dried again.

The impregnation and drying processes are repeated a
third time.

(6.) The cloth is steeped in a weak solution of pearlash,
of the specific gravity 1-0075 to 1*01, heated to the tempera-
ture of 120°. From this liquor it is wrung out and again
dried.

(7.) A mixture is made of the following substances : —
1 gallon gallipoli oil
3 gallons soda ley, of sp. gr. 1*06
1 gallon caustic potash ley, of sp. gr. 1*04,
diluted with as much water as will make up the whole to
22 gallons. In this liquid it is soaked as it was with that
of No. 3.

The cloth thus impregnated is in fine weather dried on
the grass, in rainy weather in the stove.

168 Dr. Thomas Thomson on [March.

(8.) The process No. 7 is repeated thrice, and after each
soaking the cloth is exposed for some hours on the grass,
and finally dried in the stove.

(9.) The cloth is steeped in a mixed ley of pearlash and
soda, of the specific gravity 1*01 to 1*0125, heated to the
temperature of 120°. It is allowed to drain for some hours
and then well washed. It is then dried in the stove. The
object of this process is to remove any superfluous oil which
might adhere to the cloth. Should any such oil be present,
the succeedingprocess, the galling, couldnot be accomplished.

(10.) For the galling, 18 lbs. of alleppo galls are to be
boiled for four or five hours in 25 gallons of water, till the
bulk is reduced to about 20 gallons. This liquid, after
straining, is strong enough to impregnate 100 lbs. of cloth,
with the requisite quantity of nut galls. Of late years
sumach from Sicily has been substituted for nut galls ;
33 lbs. of sumach being reckoned equivalent to 18 lbs. of
nut galls. Sometimes a mixture of 9 lbs. of nut galls and
16 j lbs. of sumach is employed.

In this liquor, heated to 80° or 100°, the cloth is fully
soaked. The sumach gives the cloth a yellow colour, which
serves to improve the madder-red, by rendering it more
lively.

(11.) The next process is to fix the alumina on the cloth.
This step (as has already been observed) is essential, because,
without it the madder dye would not remain fixed.

In this country alum is used by the manufacturers ; but
in many parts of the Continent acetate of alumina is em-
ployed. To form the alum liquor of the Turkey-red dyers,
to a solution of alum of the specific gravity 1*04, as much
pearlash, soda, or chalk is added, as is sufficient to preci-
pitate the alumina contained in the alum. Through this
muddy liquor, (which should have a temperature from 100°
to 120°,) the cloth is passed and steeped for twelve hours.
The alumina is imbibed by the cloth, and unites with its
fibres.

(12.) The cloth thus united with alumina is stove-dried,
and then washed out of the alum liquor.

(13.) These essential preliminary steps having been taken,
the cloth is ready to receive the red dye.

From 1 to 3 lbs. of madder, reduced to the state of pow-
der, for every pound of cloth is employed ; the quantity

1835.] Calico-Printing. 169

depending upon the shade of colour wanted. The cloth is
entered into the boiler while the water is cold. It is made
to boil in an hour, and the boiling is continued for two
hours. During the whole of this time the cloth is passed
through the dyeing liquor by means of the winch.

For every 25 lbs. of cloth dyed, one gallon of bullock's
blood is added. This is the quantity of cloth dyed at once
in a boiler. The addition of the blood is indispensable for
obtaining a fine red colour. Many attempts have been
made to leave it out, but they have been unsuccessful. I
suspect that the colouring matter of blood is fixed upon the
cloth. Its fine scarlet tint will doubtless improve the colour
of madder- red.

(14.) Madder contains two colouring matters, a brown and
a red. Both are fixed on the cloth by the dyeing process,
giving the cloth a brownish red, and rather disagreeable
colour. The brown colour is not nearly so fixed as the red.
The object of the next process, called the clearing process, is
to get rid of the brown colouring matter. The cloth is
boiled for twelve or fourteen hours in a mixture of 5 lbs.
soda, 8 lbs. soap, and from 16 to 18 gallons of the residual
liquid of No. 9, with a sufficient quantity of water. By this
boiling the brown colouring matter is mostly removed, and
the cloth begins to assume the fine tint which characterizes
Turkey-red dyed cloth. It is still further improved by the
next process.

(15.) Five or six pounds of soap, and from sixteen to
eighteen ounces of protochloride of tin, in crystals, are dis-
solved in water in a globular boiler into which the cloth is
put. The boiler is then covered with a lid, which fits close,
and the boiling is conducted under the pressure of two
atmospheres, or at the temperature of 250|°. The boiler is
furnished with a safety valve and a small conical pipe, the
extremity of which has an opening of about x|ths of an inch
in diameter, from which there issues a constant stream of
steam during the operation. The salt of tin is found mate-
rially to improve the colour. Probably the oxide of tin
combines with the oleaginous acid of the soap (fixed in the
cloth.) This insoluble soap doubtless unites with the red
colouring matter of the madder, and alters the shade.

(16.) After all these processes, the cloth is spread out on

170 Dr . Thomas Thomson on [March.

the grass, and exposed to the sun for a few days, which
finishes the clearing.

Such is a very short, but accurate, sketch of the
Turkey-red dyeing, as practised in the principal works in
Glasgow. Many attempts have been made to shorten the
processes, but hitherto without success. The impregnation
with oil, or rather soap, is essential. If one, two, or three
immersions be omitted, the- red is inferior in proportion to
the omissions. Doubtless this soap combines with and
remains attached to the cloth. And the same remark
applies to common soap.

Cloth bleached with chloride of lime does not produce a
good red. Doubtless the fibres of the cotton wool combine
with lime or rather with sulphate of lime, which, by decom-
posing the oleaginous soap, prevents it from combining with
cloth. But cloth bleached by the old process, namely,
boiling in ley or soap, and exposure to the action of the
sun answers perfectly. The colours would be as good
without the galls as with them. But there would be con-
siderable difficulty in sufficiently impregnating the cloth
with the alum liquor, without its being previously passed
through the alum decoction, especially if the cloth be in
the least degree greasy.

The whole cloth, of which a specimen is shown at No. 18,
is dyed Turkey-red. The white stars with eight rays con-
stitute an after process, and are formed by discharging the
dye by means of water impregnated with chlorine. Fifteen
pieces of cloth, dyed Turkey-red, are laid flat upon each
other on a plate of lead of the size of the pocket handker-
chief. Another plate of lead is laid over them, and the
two plates are pressed violently together, either by means
of screws, or in the more perfect establishments, by the
Bramah press, exerting a pressure of about 200 tons.
Through the upper plate are cut holes corresponding exactly
with the star, cross, &c, to be discharged on the cloth. A
solution of bleaching powder, mixed with an acid to set the
chlorine at liberty, is made to flow over the upper plate,
and forced by ingenious contrivances to pass through the
cavities cut in the plate. It penetrates through all the
fifteen pieces of cloth, discharging the colour, while the
violent pressure effectually prevents it from spreading to
those parts of the cloth which are to retain the colour.

1835.]

Calico- Printing .

171

When this process was first put in practice, the edges of
the holes in the lead were left sharp, the consequence of
this was, that the violent pressure to which they were sub-
jected caused them to cut the cloth, so that the whole
spots soon fell out, leaving holes in their place. This was
ascribed to the corrosive effect of the chlorine, whereas, it
was in reality owing to the bad construction of the leaden
plates. Henry Monteath & Co. were the first persons who
manufactured these handkerchiefs, or bandanas, as they are
called, and they realized by them a very large fortune.

19. Two Turkey-Reds and White.

iSS 4&

This is an improvement on the original bandanas described
in the last paragraph. The two reds are dyed at the same
time ; difference in the tint is owing to the aluming, a much
greater portion of the alumina, being fixed upon those parts
of the cloth that are to have the deep red than those that are
to receive the light red. The white flowers and sprigs are
produced by discharging the dye. The method of doing
this was originally contrived in France. Mr. Thomson of
Primrose Hill, near Clitheroe, took out a patent for it about
eighteen years ago, which having now expired, the process
is open to every person. To accomplish it, a solution of
tartaric acid thickened with gum-senegal, is printed in the
usual way upon those parts of the cloth that are to be
white. The cloth is then passed slowly through a solution
of chloride of lime. The acid disengages the chlorine from
the bleaching liquor, and the free chlorine discharges the
colour. The cloth is immediately passed through pure
water to prevent the discharge from spreading.

172

Br. Thomas Thomson on [March

20. White Discharge upon Bronze.

The cloth is first soaked in a solution of sulphate or
chloride of manganese, and dried. It is then passed through
a strong caustic alkali, by which the white hydrated
protoxide of manganese is precipitated on the cloth. This,
by exposure to the air gradually darkens, being converted
into sesquioxide ; and this change is further promoted by
the action of bichromate of potash.

Protochloride of tin is the substance best adapted for
producing white figures upon this ground. By its means
chloride of manganese is produced, which is readily removed
by water ; while peroxide of tin either takes the place of the
manganese or may be also rendered soluble by employing a
free acid along with the solution of tin.

21. White upon Blue.

The blue vat is a solution of deoxidized indigo in lime-
water. To form it the indigo is ground to a fine paste
with water, and then mixed with sulphate of iron and an

1835.] Calico- Printing. 173

excess of lime. In a few hours the indigo is deoxidized
and dissolved. The new products, peroxide of iron and sul-
phate of lime, are allowed to subside, and a clear yellow
coloured solution of indigo remains. When a piece of cloth
is dipped in this solution the yellow indigo immediately
quits the lime to deposit itself upon the fibres of the cloth.
When the cloth is exposed to the air the indigo soon recovers
its oxygen and becomes blue.

The indigo solution has a yellow colour, but its surface is
always blue ; or, if very strong, copper coloured, from the
oxidizement of the indigo by the contact of air. Acids
throw down from it white indigo ; while those metallic
oxides that readily part with their oxygen throw down the
indigo in a blue state. This is the case with the sesqui-
oxide and binoxide of manganese, the salts of copper and
its blue hydrate. And these substances are taken advantage
of by the printer to produce various effects upon his calicoes.
In the specimen before us oxide of copper has been employed
to prevent the indigo in the blue vat from attaching itself
to particular parts of the cloth. For this purpose a solution
of the sulphate or acetate of copper made into a paste with
flour or pipe-clay and gum-senegal, is printed upon the
white cloth, and when dry, the whole is immersed in the
blue vat. The indigo becomes-fixed upon those parts of the
cloth where no paste has been applied ; but, on the surface
of the paste it is arrested by the copper, which, by yielding
oxygen, renders the indigo blue and insoluble before it can
reach the cotton. A little of the copper remains after wash-
ing, which is taken away by means of sulphuric acid.
(To be continued.)

Article II.

Researches into the Number of Suicides and Murders committed
in Russia in 1821-22. By M. C. T. Hermann, [read 1832
and 1833.] {Peter sburgh Memoirs, ii. 257.)

The results detailed in this paper were procured from the
governors of the different provinces. The population,
according to the returns derived from them, of the pro-
vinces collectively, was in 1820, 39,030,072; and in 1827,
39,572,633. Since 1812 the increase of the population has
been very rapid. . For the seven years alluded to, the increase

174 M. C. T. Hermann on the number of [March.

of the industrious population was 75,508 annually. Her-
mann begins with the western provinces of Moscow, Yaros-
lav, Vladimir, Riazan, Toula, Kalouga, Kostroma, Orel,
Koursk, and Voronega, where the people are chiefly
Russians. In 1820 the population of these provinces
amounted to 10,593,251. In this population there were in

1821, 520 suicides; and in 1822, where the cases were
investigated, 505; total, 1,025; mean = 512£ ; while the
number of non-investigated suicides was in 1821, 132; and

1822, 168 ; total 300; mean 150. The total of these two
classes of suicides amounted therefore in 1821 to 652; and
for 1822, 673; total 1,325; mean 662 J. The number of
homicides in 1821 was 223, and in 1822, 200; total 423;
mean 211 J. The proportion to the population therefore is,

1 investigated suicide to . . 20,669 inhabitants.
1 non-investigated suicide to 70,621 ,,

1 suicide of both classes to 15,989 ,,

1 homicide 50,086 ,,

Hence, the suicides were above three times more numerous
than the homicides, and the latter to the former in the
proportion 1 to 3J.

The following table exhibits a relative statement of the in-
vestigated suicides in the different governments for 1821-22 :

Investigated. Non-investigated.

,T 5 39^ town 110 } 22 town

Moscow. . . ^72|country H2 \ 9country.

Yaroslav 684 - 16

Vladimir 55-13*

Orel 48* - 10

Toula . .44|-11

Kalouga 40-8

Voronega 38-32

Riazan 37 - 22£

Kostroma 8-1

512£
From this enumeration, compared with former years, it
appears that the number of suicides has not increased in
Kostroma. In Toula and Kalouga the difference is trifling.
But in the most industrious governments, where the passions
are more liable to be excited, as Moscow, Saratov, Vladimir,
the number is on the increase. The proportion of suicides
to the population appears from the following table : —

1835.] Suicides and Murders in Russia in 1821-22. 175

Town of Moscow : one suicide to 6,250 of both sexes.

Government of 11,678

Vladimir .... 18,207
Kalouga .... 20,770

Toula 21,165

Koursk 21,536

Orel 24,362

Riazan 28,697

Voronega .... 32,710
Kostroma .... 120,546
As it is not easy to determine when there is no examina-
tion into a case, what is the cause of death, the uninvestigated
tables may contain some errors. But in the following
enumeration the nonwnvestigated suicides are alone referred
to:--

Inhabitants

Suicides

Square Miles.

to the

not

square mile.

Investigated.

Voronega . . .

1,363

985

32

Moscow .

. . .

481

2,488

31

Riazan .

■ . .

731

1,455

22£

Yaroslav .

. .

609

1,444

16

Vladimir

. . .

874

1,145

13}

Orel . . .

790

1,495
1,757
1,535

10

Toula . .

542

11

Kalouga .

, . .

541

8

Koursk .

, . .

743

1,768

5

Kostroma

' ' *.

1,439

671

1

Kostroma, in all the previous statements, presents always
a very extraordinary example of good morality. The non-
investigated suicides in that province amount only to one,
although it has the greatest extent ; much wood in it, and
a very active navigation on the Volga. The quality of its
soil is very inferior, the agriculturist has much to do in
cultivating it, for nature has done little.

Voronega, with an immense extent of surface, possesses
but a small population. It forms part of the Steppes, and
hence the number of non-investigated suicides.

Koursk is of great extent, but has a more concentrated
population, and few non-investigated suicides.

Orel, with a greater extent and fewer inhabitants, has

176 M. C. T. Hermann on the number of [March.

double the number of these cases. Riazan possesses a
woody and marshy surface.

Vladimir is extensive, with a concentrated population.
Toula, which is of considerable size, has a good population,
and is more of a manufacturing than agricultural country.
There are few non-investigated cases. Kalouga is an agricul-
tural country, and contains still less. It is a striking proof
of the good state of the police in Moscow, that there are
only nine cases of doubtful issue in that city.

In comparing the population with the number of doubtful
suicides, we find that one occurs in

Vladimir for every . 37,088 inhabitants.
Voronega .... 41,968
Riazan . . .. 47,190

Yaroslav .... 54,995

Toula 85,715

Moscow, Government 94,077
Capital . . 11,731

Kalouga 103,852

Orel 118,105

Koursk 202,735

Kostroma .... 914,372
It is remarkable that Koursk, on the S.W. of this plain
(of the Oka,) and Kostroma, on the E.N.E., bear the most
favourable results.

Kalouga, Toula, Moscow, and Yaroslav, on the N.W.,
surpass in this respect the governments situated more
towards the.E. Vladimir, Riazan, and Voronega.

Homicides. — The mean number of these for the two years
is 21 14, which are divided among the governments as
follows : —

Moscow . . 33s — (9* in the town, 24 for the government.)

Orel .... 28

Koursk . . 27

Toula ... 27

Riazan . . . 234

Kalouga . . 194

Vladimir. . 174

Yaroslav . . 174

Voronega . 104

Kostroma . 74

2114

1835.] Suicides and Murders in Russia in 1821-22. 177

Comparing this table with the former results, we find
Kalouga and Kostroma holding the same situation. There
are fewer homicides in 1822 in Moscow than in 1820, and
the same observation holds good with regard to Orel, Toula,
and Vladimir, &c.

With regard to the relation of the homicides and suicides
to the order in which the governments follow, for these
crimes in 1822, it appears that the capital and government
of Moscow has the greatest number of these two kinds, and
Kostroma the least. Suicides are more frequent than homi-
cides in Yaroslav and Vladimir, and the latter more nume-
rous in Orel, Toula, Riazan and Kalouga. This is perhaps
explained by the greater or less concentration of the
population.

The proportion of the homicides to the population is as
follows :

Moscow, Capital ... 1 to 27,125) q9 Qfif>
Government . . 35,279 S '

Toula 34,921

Orel 42,180

Kalouga 42,629

Riazan 45,608

Koursk 48,655

Yaroslav 50,281

Vladimir 57,222

Voronega 127,903

Kostroma 128,583

Here, it is remarkable that Voronega and Kostroma, the
most extensive governments, exhibited the most favourable
state.

With regard to the proportion of the sexes who have
committed crimes, the returns of registers show that in

1821, 428 men and 92 women committed suicide.

1822, 406 „ 99 „

Total, men . . 834 mean for the year 407
Total, women 191 ,, ,, 95*

or one women to 41 men.
Of non-investigated cases in

1820, there were 111 men, 21 women.
1822, „ 146 „ 22 „

Total, men . . 257 ; mean 128i
Total, women .43 ,, 211
or one woman to six men.

VOL. I. N

178 M. C. T. Hermann on the number of [March

Total Suicides. ,

1821, Men 539. Women 113

1822, „ 552. „ 121

1091 234

mean 545* mean 117

or one woman to 4^ men.

The interest of these details increases when we take into
consideration the condition of the people among whom
these crimes exist.

Peasants.

1821, 387 men, 71 women. | Total, 787 men; mean 393J

1822, 400 „ 98 „ ] „ 169 women „ 84J

Mean of the two sexes, 478.

Merchants, Workmen, and Free People.

1821, 77 men, 22 women

1822, 77 „ 16 „

Total, 154 men ; mean 77
38 women ,, 19

Mean of the two sexes, 96.

Soldiers.

1821, 57 men, 17 women | Total, 110 men ; mean 55

1822, 53 „ 6 „ | „ 23 women „ 11J

Mean of the two sexes, 66h.

Nobility.

1821, 15 men, 3 women | Total, 32 men; mean 16

1822, 17 „ 1 „ | „ 4 women „ 2

Mean of the two sexes, 18.

Clergy.

1821, 3 men — women Total, 8 men; mean 4

1822, 5 „ „ J

To render this statement more interesting, it would be
proper to have an enumeration of the population of the
various classes. Hermann, however, gives only a rough
calculation, which is as follows : — Considering the total
10J millions, there are of

Peasants .... 8,000,000

Third state
Clergy . .
Nobility .
Military .

2,000,000
100,000
200,000
200,000

1835.] Suicides and Murders in Russia in 1821-22. 179

According to the different conditions a suicide occurs in
the proportion among

Peasants of 1 to 16,757* inhabitants.
Tiers etat „ 20,833$
Soldiers „ 3,009
Nobility „ 11,111
Clergy. „ 25,000

Among the peasantry there are
At Moscow, 95 suicides in a male population of 424,605
Proportion of suicides 1 to 4,446|.

Yaroslav 66h 368,839

„ 5,997*

Vladimir 48* 461,682

„ 9,518|

Voronega 27 274,329

„ 10,170*

Toula 31* 359,259

„ H,461|

Kalouga 31 358,940

„ 11,5781

Riazan 36 434,640

„ 12,0731

Koursk 26^ 339,635

„ 12,8161

Orel 23i 488,929

„ 20,805*

Kostroma 7* 399,248

„ 53,233*
Among the tiers etat the numbers are :

Koursk 21 suicides in 264,068

or 1 in 12,574f

Voronega 15 292,725

„ 19,515

Orel 15 144,303

9,620|

Moscow 8* 51,218

6,0251

Riazan 8 54,605

6,825|

Vladimir 3 . . 13,075

„ 4,358*

Yaroslav 2* 15,903

„ 6,361*

Kalouga 2 . . . 20,854

„ 15,427

Toula 2 / 49,528

„ 24,764

Kostroma no example . . 11,179

n2

180

Mr. C. T. Hermann on the number of [March

Among the clergy, in two years, at Moscow, the propor-
tion is 1J to . . . . 6,853 Riazan, 1 to . . 6,897

Yaroslav, 1 to . . 3,664 Koursk, J to . . 7,035

In the other six governments, among 40,307 persons,
there are no suicides among this class.

It appears, therefore, that suicides happen most frequently
among the peasants of Moscow and Yaroslav, and more
rarely among those of Orel and Kostroma. The free agri-
cultural labourers belonging to the third class are very
numerous in Koursk, Orel, and Riazan. <

The nature of the death is interesting in relation to the
manners :

Men.

Women.

Total.

Deaths from drunkenness .
,, by hanging . . .
,, brule la cervelle* . .
,, cutting the throat .
,, drowning ....
,, poisoning ....

242

136

19

11

2

29

63

1 in 1821

1

1

1

271
199

The cases from drunkenness occurred in the governments
in the following proportions :

Men.

Women.

Total.

Moscow, town . . .
,, government .

14*
44

4
4

\66h

Yaroslav . . .

51

5

56

Vladimir

39

4

43

Koursk

24

2

26

Riazan

16

H

18

Kalouga

16

H

17*

Toula

12

2

14

Orel

11

3

14

Voronega

8

If

9*

Kostroma

6§

i

7

The cases of premeditated suicide are most frequent among
the peasants and soldiers, and are performed by hanging, and
occur most numerously in Moscow, Koursk, and Orel,
being rare in Yaroslav and Vladimir, and almost unknown
in Kostroma. The species of death by violence among the
nobles, and sometimes among the soldiers, is bruler la cervelle.
At Moscow a magistrate and a student died in this manner.
* Literally, burning or searing the brain.

1835.] Suicides and Murders in Russia in 1821-22. 181

Among women it never happens. Cutting the throat is not
common. At Moscow, in 1821, a stranger cut his throat
with a razor. There were only eleven cases in eight govern-
ments. Poisoning is very rare. At Moscow, in 1822, a
soldier was poisoned, and a female servant, by her lover.
At Yaroslav, in 1822, a young officer was poisoned ; in 1822
a peasant; and in Voronega, in 1821, a soldier suffered the
same fate. In six governments, only seven cases of pre-
meditated suicide occurred. In 1822 a student at Moscow
threw himself from a window, and in the same year, a
merchant of a melancholic temperament killed himself in
a similar manner.

The causes which have occasioned the suicides are ex-
tremely interesting, as they throw some light upon the
analogous situation of persons of the same class ; but, in
general, they are unknown. A few, however, have been
ascertained.

In Moscow a peasant hanged himself in a passion during
1821. In Kalouga, a peasant, overcome with melancholy,
strangled himself in 1822. A peasant at Riazan, in 1821,
afraid of being inlisted; in 1822 another, afraid of being
punished by his master, committed the same crime. Similar
acts were perpetrated by peasants in Kostroma, from low
spirits, in 1822; by another in Toula in 1821, in conse-
quence of being punished by his master ; and a third in 1821,
in Orel, afraid of punishment ; a fourth for having lost his
horse, which a peasant had taken from him for debt.

In a population of 10 J millions one homicide occurs for
every 49,645£ inhabitants. Of this number 141 are men,
33 women, and 37s children : in the proportion of

Men to women . .

,, children . .

Women ,, . .

Both Sexes ,,

For a mean of two years there

among

4* to 1
3* „ 1

4J

1}

1

are of assassinations

Men.

Women.

Children.

Total.

Peasants . . .

10H

25*

31

158

Free people . .

19|

Si

2

25

Military . . .

ioI

ll

3

15

Nobility . . .

6

2

—

8

Clergy ....

31

i

11

5i

182

Mr. C. T. Hermann on the number of [March

The proportion among the sexes are, among the

Peasants.

Free people.

Military.

Nobility.
Clergy.

Men to women

,, children
Women ,,
Both Sexes ,,
Men to women

,, children
Women ,,
Men to women

,, children
Women ,,
Both sexes ,,
Men to women

4i children
Women

4 to

3i„

1 „
41

9*„
1*„
7 „
3*„
1 h
4 „

3 ;,

7 „

1 „
21 „

Both sexes,,

The greatest number of these assassinations have been
perpetrated by the fist or a stick, by people of low birth, in
consequence of quarrels in the streets, inns, or roads. The
peasant in Russia is not armed as he is in Spain, Portugal,
and Turkey, and hence, when he commits murder, it may
be in consequence of drunkenness or anger, he employs the
first instrument he can lay his hand on to satisfy his feel-
ings. The children who have perished by violence are
principally illegitimate, and have been murdered by their
mothers, not having the means of procuring admission for
them into the government establishments. Those who have
been murdered by the weapons mentioned, are enumerated
in the following table : —

Men.

Women.

Children.

Total.

Koursk

15

3J

1

91J

Moscow, government

9

1

2

|>

,, town . . ,

—

n

41

Riazan . . .

104

n

2J

14|

Toula

7*

n

H

13J

Orel

8

3

2

13

Yaroslav ....

81

i

2

11|

Vladimir . . .

9

i

1

11

Voronega . . .

5

ii

2

8J

Kalouga . ♦ .

6

1

11

Kostroma . . ,

3*

1

I

5

Total

82

17

23

122

1835.] Suicides and Murders in Russia in 1831-32.
Persons murdered by the knife or hatchet.

183

Men.

Women.

Children.

Total.

Moscow, government.

3

—

Sh

,, town . .

2

1

3

Toula . . .

4

1*

—

5J

Riazan . ,

3

1

—

4

Orel . .

3

i

Sh

Koursk .

n

I

3

Kalouga .

i

i

—

H

Yaroslav . ,

i

i

H

Vladimir .

i

1
5

—

n

Kostroma

i

i

2

A very common method of murdering is, however, by
strangling or choaking. In ten governments, twenty men,
six women, and three children, suffered in this way. Only
two cases of poisoning occurred.

The following table embraces in one view the various
descriptions of murders : —

Killed by fist or bludgeon .
Killed with knife or hatchet
Strangled or suffocated . .

Drowned

Killed with fire-arms . . .
Poisoned

Men.

Women.

Children.

92

17

23

26

6

—

20

6

3

5

3J

10

4

1

—

2

1

1

149

34J

37

With regard to the state of families, we find that in
Koursk, a father was assassinated by his two sons in 1822;
a mother by her son, at Kalouga, in 1822. Five husbands
were murdered by their wives, and twenty-three wives by
their husbands.

At Koursk, a son was assassinated by his father in 1822,
the only instance in ten governments. At Toula, in 1821,
two brothers were killed by their brothers ; and at Orel,
in 1822, a similar instance of one person occurred. Among
the clergy, at Vladimir, the wife of a deacon, in 1821 , killed
her son ; in the government of Moscow the wife of an inferior,
and in Toula, in 1822, the daughter of a priest killed their
illegitimate children. In Moscow, in 1822, an uncle mur-
dered his nephew. The same year, at Kalouga, a nephew
killed his uncle ; and at Koursk, in 1821, a grandfather his

184 Notice of some Recent [March

grandson. In 1822 there were twelve assassinations in
families, while in 1 821 there were only four.

The majority of perpetrators of murders, who amounted to
423 for two years, are unknown; 217 are in this state, but
206 have been discovered. Of this number, 127 were com-
mitted by peasants, in the governments of Riazan, Orel,
Koursk, and Voronega ; twenty by soldiers or deserters ;
seven by free people ; six by employed persons ; and four
by the nobility. Eighty murders have been perpetrated by
women, viz. : seventy-two children killed by their mothers
in two years, five husbands by their wives, and three un-
certain cases. The remaining 343 murders were committed
by men.

The causes of these have generally been desire of gain,
the vagabond life of deserters, melancholy, but above all,
the gross manners of the lower classes. A peasant slew a
guard of the forest in 1821, in Moscow, because he pre-
vented him from escaping from the wood. A peasant of
Vladimir, in 1822, killed another for having trampled on
his rye. Murders on the high roads have generally been
committed by soldiers who have deserted. In 1821, in
Vladimir, three merchants slew three persons sent by their
masters to transact some business.

In 1822, in Toula, two proprietors were killed by their
domestic slaves from discontent. In 1821, at Riazan, a
proprietor was murdered from an unkown cause. Similar
cases occurred at Kostroma, Koursk, and Orel. At Koursk,
in 1821, a peasant wishing to save another from recruiting,
put poison in his ears, of which he died. Among the clergy
there are five murders among the inferior grade. A person
of noble extraction, employed at the manufacture of Toula,
killed the person with whom he lodged, from hatred, in
1822. In three other cases, anger or drunkenness were
the causes of murders.

Article III.

Notice of some Recent Improvements in Science,
(continued from p. 131. )

Compounds of Azote. — In organic chemistry we can separate
from one substance, by means of different re-agents, a number

1835.] Improvements in Science. 185

of bodies differing very materially in their nature from the
substance in which they were previously combined . To ascer-
tain if this fact held good in reference to inorganic substances,
Liebig submitted to examination a ternary compound, which
he formed in the following manner : (Ann. de Chim. lvi.) He
passed through a solution of sulpho-cyanodide of potassium a
current of chlorine gas . When boiled with dilute nitric acid
an orange-yellow body precipitated, which, in its composi-
tion, was identical with the radicle of hydrosulphocyanic acid.
Hence, he considered it as sulpho-cyanogen. This substance,
when heated, is decomposed, and a quantity of sulphur and
sulphuret of carbon comes off, while a yellow powder remains,
which was employed by Liebig in his subsequent researches,
Liebig terms this citron-coloured powder mellon. When
exposed to a temperature at which glass melts, it is decom-
posed into pure cyanogen and azote. Analyzed with oxide
of copper, carbonic acid and azote are procured in the pro-
portion of 3 to 2. He considers it composed of

Carbon . . 458-622
Azote . . . 708-144

1166-766
and explains its formation by conceiving 2 atoms of sulphuret
of carbon = 2 C -j- 4 S and 4 atoms of sulphur to be
subtracted by the heat from 4 atoms of sulpho-cyanogen,
whose composition he states = 8C + 8A-f8S. There
remains therefore 6 C 4- 8 A.

Mellon, when heated in dry chlorine gas, combines with
it and forms a white body, possessing a strong smell, and
acting upon the eyes. The same substance may also be
procured by heating together two parts chloride of mercury
and one sulpho-cyanodide of potassium. Mellon may be
produced by heating sulpho-cyanodide of potassium in a
current of dry chlorine gas. With potassium mellon com-
bines and forms a transparent easily fusible mass, which
dissolves in water, imparting to it a taste of bitter almonds,
precipitating the metals not as cyanodides, and is decom-
posed by the agency of acids.

2. Melam.— This substance is procured from hydro-sulpho-
cyanate of ammonia, a salt which is formed by distilling
together two parts of muriate of ammonia, and one part

186 Notice of some Recent [March

sulpho-cyanodide of potassium. The composition of the
hydro-sulpho-cyanate of ammonia is analogous with that of
urea, sulphur being substituted for the oxygen of the
latter. When heated, the first effect is to disengage a con-
siderable quantity of ammonia, then sulphuret of carbon,
and soon sulphuret of ammonia appears in the neck of the
retort. After the distillation is over a new substance is
observed in the retort, mixed with chloride of potassium
and sal-ammoniac. By washing, the salts are taken up,
and the grey matter called melam, which remains, is inso-
luble in water, ether, and alcohol. It is frequently mixed
with a little sulphur, which may be removed by levigation.
It is decomposed by a strong heat into ammonia, cyanogen,
and azote. If it is boiled in potash it readily dissolves, and
the filtered liquor deposits a white granular matter, which
is melam in a state of purity. Analyzed by means of oxide
of copper, melam yielded,

Carbon . . . 30*550
Hydrogen . . 3-860
Azote .... 65-589

100-000

When boiled with nitric acid it dissolves, and crystals of
cyanuric acid are deposited on cooling. Fused with potash,
cyanic acid is formed. Boiled with a solution of the same,
and concentrated, it deposits crystals. The supernatant
liquor retains a trace of this substance, which is precipitated
by sal-ammoniac or carbonate of ammonia, affording a white
gelatinous product, identical with the substance procured
by treating melam with muriatic acid.

3. Melamine. — By this name Liebig distinguishes the
substance which has just been described. To obtain it in a
state of purity, he recomends taking the residue after the
distillation of 2 lbs. sal-ammoniac, and 1 lb. sulpho-cyanodide
of potassium, and adding to it a solution of 2 ounces of
potash in 3 or 4 of water, and boiling them until the liquid
be quite clear ; after which it is to be filtered and evapo-
rated gradually, when crystals of pure melamine are
deposited. These crystals are octohedrons, with a rhombic
base, in which the angles are about 75° and 115°. They
are white, contain no water, and are not altered by the air.

1835.] Improvements in Science. 187

Cold water dissolves very little melamine, but hot water
readily dissolves it. Melamine combines with all the acids,
and forms very characteristic salts. When heated with a
solution of sal-ammoniac it gives out ammonia, and com-
bines with muriatic acid. The sulphates and nitrates of
copper, the salts of zinc, iron, manganese, are decomposed
by a solution of melamine in water, and the oxides are
precipitated. Fused with potash, cyanate of potash is
produced ; if it is in excess, mellonuret of potassium is
formed. Liebig found the composition of melamine to be

Carbon . . . 28*460
Azote .... 66-673
Hydrogen . . 4*865

100-000
Melamine, heated with nitric and sulphuric acids, yields
ammonia, and a substance which remains dissolved in the
acid, and is identical with the product of the action of con-
centrated acids upon melam.

Melamine has a strong affinity for sulphuric acid. The
formation of needle formed crystals is the result of their
combination, which are scarcely soluble in cold but easily
soluble in hot water.

Nitrate of Melamine is readily formed by adding nitric
acid to a cold solution of melamine in water, until the
liquid be strongly acid. It is in the form of long needles.
By combustion this salt gives carbonic acid and azote, in
the proportion of 6 to 7.

When a solution of melamine is added to nitrate of silver
a white crystalline precipitation ensues, which consists of
1 atom melamine . . . 16*
1 ,, nitric acid ... 6*75
1 ,1 oxide of silver . . 14-75

37-5

Oxalate of melamine is less soluble in water than the
nitrate. It affords, by analysis, carbonic and azote in the
proportions of 8 to 6, and obviously consists of

1 atom melamine . . . 16*
1 ,, oxalic acid . . . 4*5
1 ,, water .... 1*125

21*625

188 Notice of some Recent [March

Acetate ofmelamine is very soluble in water, and crystal-
lizes in large rectangular flexible plates.

Phosphate of melamine is very soluble in boiling water.
A concentrated solution leaves, on cooling, a white mass
formed of needles placed concentrically. Formate of mela-.
mine dissolves easily and crystallizes.

4. Ammeline. — This substance remains in solution in the
caustic potash when melamine is prepared. It may be
separated by saturating the alkali with an acid. It is best
to employ acetic acid, because the mineral acids dissolve
it in excess. Carbonate of ammonia and sal-ammoniac
precipitate it also from its alkaline solution. After preci-
pitation it should be washed and dissolved in nitric acid.
Concentrate the solution and long four-sided colourless or
slightly yellow prisms will be separated; or precipitate
it from its solution in nitric acid by means of caustic am-
monia, or carbonate of ammonia.

Ammeline is a white shining crystallized substance when
precipitated by ammonia, insoluble in water, alcohol, and
ether, but soluble in the caustic alkalies and in most of the
acids. When heated it affords a crystallized sublimate
of ammonia, and, if the heat is carried far enough, is
converted into cyanogen and azote, leaving no residue.
Towards acids it acts as a base, but it is weaker than
melamine. Its salts are partially decomposed by water.
Ammeline, analyzed by oxide of copper, afforded

Carbon .... 28*553
Azote . . . . 55-110
Oxygen .... 12*451
Hydrogen . . . 3*884

100*000
Nitrate of ameline consists of

1 atom ammeline . 16*
1 ,, nitric acid . 6*75
1 „ water. . . 1-125

23*875

Nitrate of ammeline affords with nitrate of silver, a pre-
cipitate of the same nature as that produced by melamine,
being white and crystalline, and consisting of one atom

1835.] Improvements in Science. 189

each of ammeline, nitric acid and oxide of silver. Liebig
explains the formation of ammeline and melamine, by con-
sidering that from 2 atoms of melam and the elements of
2 atoms of water, 1 atom of melamine and 1 atom of amme-
line result.

By boiling melam with hydrochloric acid, ammeline and
ammonia are produced by the aid of 2 atoms of water.
Cyanate of potash is produced by the action of potash on
dry ammeline, the cyanic acid in this case being formed by
1 atom of ammeline combining with 2 atoms of water, the
resulting product being 3 atoms of acid.

5. Ammelide results from adding alcohol to a solution of
melam or melamine in concentrated sulphuric acid. It
precipitates in the form of a thick white precipitate. It
may be also obtained by heating nitrate of ammeline till the
soft mass becomes solid, or by boiling melamine in concen-
trated nitric acid. By boiling impure melam in dilute
sulphuric acid, it dissolves, and crystals of sulphate of
ammeline appear by evaporation, which are decomposed,
if the liquid is boiled or further concentrated. Ammelide
precipitates by the addition of the alkaline carbonates or
alcohol. It is a white powder and seems a neutral body.
Its composition corrected by theory is,

Carbon .... 28*444
Azote .... 49-410
Oxygen. . . . 18-606
Hydrogen . . . 8-538

100-000

Liebig considers that it represents an anhydrous cyanate
of ammonia or urea, which is deprived of all its water and
the half of it ammonia. It is remarkable, that among the
transformations of melamine, its saturating properties seem
to diminish in proportion to the quantity of oxygen with
which it combines. The same observation is applicable to
vegetable bases, as for example, narcotine and solanine
whose basic functions are not well characterized, but
which are distinguished from the stronger bases by con-
taining a greater proportion of oxygen.

6. Cyanilic acid. — If the yellow powder which is obtained
from the decomposition of sulpho-cyanodide of potassium

190 Notice of some Recent [March

by chlorine, and which is mixed with chloride of potassium,
be well washed and boiled with nitric acid, it dissolves
gradually, and the liquid on cooling deposits colourless
and transparent octahedrons with a square base, which
consist of pure cyanilic acid. To accelerate the decomposi-
tion of the salt of potash, it is advantageous to add twice
its weight of common salt. At first chloride of sulphur
distils over, and latterly long needles of chloride of cya-
nogen are deposited in the neck of the retort. The yellow
residue is carefully washed and dissolved in nitric acid.
The new acid is more easily soluble in cold water than
cyanuric acid. The crystals contain water which they lose
by heating, to the amount of 21 per cent. Its composition
is, Carbon .... 28-185

Azote .... 32-640
Oxygen. . . . 36-874
Hydrogen . . . 2*300

100-000
which Liebig considers equivalent to 6 atoms of each. To
determine the atomic weight of the acid, a portion was
neutralized by ammonia, and precipitated by nitrate of
silver. 93*3 cyanilate of silver afforded 54*5 chloride of
silver. 58*2 after being exposed to a red heat, left 26-4 silver.
Hence, the atomic weight of the acid is 16-25 or double
that of cyanuric acid, which it very much resembles in its
properties. Cyanilic acid is converted into cyanuric acid
by dissolving it in sulphuric acid, adding water and crystal-
lizing. All the cyanurates and cyanilites are decomposed
when they are crystallized in an acid liquor; the bases
remain in solution, and the crystals which are formed are
cyanuric acid or cyanilic acid. In precipitating the nitrate
of silver by cyanilate of potash, Liebig obtained a substance
which had precisely the same composition as cyanurate of
silver, from which it would appear that the alkalies can
change cyanilic into cyanuric acid.

7. Chloride of Cyanogen. — During the decomposition of
sulpho-cyanodide of potassium by chlorine, besides chloride
of sulphur, chloride of cyanogen distils over, which may
be separated from the former by sublimation in a vessel
through which a current of dry chlorine is passed . Chloride

1835.] Improvements in Science. 191

of cyanogen thus obtained consists of brilliant needles,
possessing a strong disagreeable odour. To determine the
quantity of chlorine, the salt was dissolved in alcohol,
ammonia was added, and the liquid boiled with a great
quantity of water until all the spirit was volatilized.

Nitric acid was then added, in excess, and precipitation
produced by nitrate of silver. The composition of the
chloride of cyanogen was in this manner determined to be

Chlorine . . . 57*03
Cyanogen . . . 42-97

100-00
or equal atoms of chlorine and cyanogen. Chloride of
cyanogen dissolves in absolute alcohol without alteration.

8. Cyanamide. — If chloride of cyanogen is moistened with
ammonia, and gently heated, it loses its crystalline form,
and is reduced to a white powder, which is slightly soluble
in boiling water, and is precipitated on cooling in flocks.
The same substance is obtained by passing ammoniacal gas
over chloride of cyanogen in powder. A white powder is
the result, which maybe purified by washing. The chlorine
which it contains is not removed by ammonia. Potash
disengages ammonia from cyanamide. Liebig considers it
analogous in its composition to oxamide, and to a chloride
of cyanogen.

Uric Acid. — Liebig states that he was encouraged to make
the preceding researches in the hope of finding a new com-
bination which would throw some light upon the composi-
tion of uric acid. Liebig considers the determination of
Dr. Kodweiss, with respect to the proportion of azote, to
be nearer the truth than any other. He himself makes the
composition of uric acid :

Calculated. Experiment.

Carbon ... 36-11 - 36-073

Azote .... 33-36 - 33-361

Oxygen ... 27-19 - 28*126

Hydrogen. . 2-34 - 2.441

Method of procuring Oxide of Chromium in Crystals. —
Wohler has found that the green oxide of chromium, which
is well known as a green powder, may be obtained in the

192 Notice of some Recent [March

state of crystals by passing the vapour of chloro-chromic
acid through a red hot glass tube. # A mixture of chlorine
and oxygen is formed, and the crystals of oxide are deposited
in the tube. Thus prepared, it is not green but black, pos-
sessing the metallic lustre, and has the same form as
native peroxide of iron, (fer digiste or rhombohedral iron
ore) which he considers a proof of the ismorphism of these
two oxides. The spec. grav. in the crystallized state differs
little from that of peroxide of iron, being 5*21.

It scratches rock crystal, hyacinth, and cuts glass. In
the crystallized state it is therefore as hard as corundum,
which, with the exception of the diamond and rhodium,
is the hardest of known substances. Chloro-chromic acid
was discovered by Professor Thomson in 1824, and is pre-
pared by distilling in a glass retort 500 gr. sulphuric acid,
with 190 gr. dry bichromate of potash, and 225 gr. of
decripitated common salt. According to Dr. Thomson, it
consists of one atom chlorine, and one atom chromic acid.
Rose considers it a combination of two atoms chromic acid
and one perchloride of chromium. Wbhler prepares it by
distilling ten parts common salt, 16*9 neutral chromate of
potash, and thirty parts of concentrated sulphuric acid.

SALTS.

Crenate of potash and crenate of soda form a yellow extract
looking mass, which becomes hard and cracks, and is neutral
to test-paper ; soluble in absolute alcohol ; scarcely soluble
in spirits of the sp. gr. 0*86. When heated gives out fumes
smelling of tobacco, and leaves alkaline carbonates.

Crenate of Ammonia leaves in the air a brown extractive
matter which reddens litmus paper. In this state it contains
much ammonia, which maybe separated by potash or lime.

Crenate of barytes is so slowly soluble in water that it
may be precipitated in a yellow flocky state, but is dissolved
by the addition of more water, and leaves a kind of varnish
on the vessel.

Crenate of lime is more easily soluble, but can be precipi-
tated. Its solubility is much affected by the presence of
other salts. It precipitates in pale yellow flocks, when a

* Ann. de Chim. lvii. 105.

1835.] Improvements in Science. 193

solution of alkaline crenate is mixed with a solution of
'chloride of calcium. The solution of this salt leaves behind
it a yellow transparent varnish. It dissolves completely in
water. When the neutral salt is mixed with excess of acid,
evaporated, and then treated with alcohol, a pale yellow
acid salt remains, easily soluble in water. A basic salt is
obtained by mixing lime-water with the neutral salt.

Crenate of Magnesia is very soluble in water.

Crenate of Alumina is insoluble in water, but the acid
salt is soluble. Ammonia does not precipitate the base,
but affords a double salt by evaporation, which is soluble,
and affords pure alumina by calcination. The neutral
crenate has a portion of its alumina precipitated by
ammonia.

Crenate of Manganese is a pale yellow powder.

Crenate of Iron is soluble in water. It may be obtained
from the ochre, by mixing the latter with water, and passing
a current of sulphuretted hydrogen through it. By evapo-
ration in a place free from air this salt remains.

Percrenate of Iron may be formed by adding crenic acid
to a solution of sulphate or chloride of iron. It is dirty-
white when dry, and earthy reddish-gray when moist. It
dissolves completely in ammonia.

Crenate of Lead is produced when crenic acid is poured
into a strong solution of acetate of lead as long as the
resulting precipitate exhibits a brown or dark-yellow
appearance. When this ceases, the crenic acid is to be
dropped into the acetate of lead, the precipitate washed
with water, or rather with alcohol, and dried in a receiver,
over sulphuric acid. When dry it is a light-gray powder,
and is to a certain extent soluble in water. It is also soluble
in acetic acid, and somewhat in crenic acid.

Crenate of Copper is precipitated from the acetate, but
not from the sulphate, by crenic acid. The precipitate is
it first dirty-white, and then light-gray, with a yellowish

'een tinge. It is little soluble in water. Its precipitation
is not complete in the cold, but is fully effected at a
temperature of 50° (122° F.)

An acid salt is formed by the addition of crenic acid to
the neutral salt. It is a gum like mass, insoluble in alcohol.

Crenate of Mercury forms a yellow flocky precipitate, and

VOL. I. O

194 Notice of some Recent [March

is formed in a solution of nitrate of mercury, by crenicacid,
or its soluble salts.

4

Cremate of Silver is formed by dropping crenic acid into a
solution of nitrate of silver. It is a grayish white matter,
becoming purplish after some time. The water of Porla
becomes red by the addition of nitrate of silver, which is
obviously owing to the re-action of the crenic acid.

The alkaline apocrenates can be best formed by pouring
apocrenic acid into the solution of an alkaline acetate, and
extracting the alkaline acetate remaining, after evaporation,
with alcohol. The matter produced forms a blackish mass,
which gives a brown tinge to its solution in water.

The ammoniacal salt becomes acid by evaporation, dissolves
readily again in water, and reddens litmus paper ; 100 parts
of dried apocrenic acid, at 212° F, give, after solution in
ammonia, and evaporation in the water bath, 113*22 parts.
Considering this to contain an atom of water and one of °
ammonia, and to constitute a biapocrenate of ammonia, the
numbers, according to the previously ascertained atomic
weight, would be 112-98.

The earthy apocrenates are dark-brown precipitates,
which, by washing, form a yellow solution. If the solution
is evaporated a brown residue remains, which is again
soluble in water. With excess of base an insoluble salt is
formed.

When apocrenic acid is added to the hydrate of alumina
in excess, the acid will be precipitated. With a small por-
tion of hydrate, apocrenate of alumina is obtained in solution.
When an alkaline apocrenate is digested with the hydrate,
it is so completely precipitated that the solution loses its
colour, and contains only a trace of crenic acid.

The precipitate is brownish black, and is a double salt.#

Apocrenate of Copper, when precipitated out of an acetic
acid solution, with excess of the latter, is acid possessing a
brown colour, and having a slimy consistence. It is soluble
in small quantity in pure water. By adding to this solution
alkali the neutral salt precipitates. It forms double salts
with ammonia and soda.

Apocrenated Protoxide of Iron is soluble in water, but by

* Whether the atomic weight of apocrenic acid is 16*5 or 16*75, must he
determined by future experiments. — Edit.

1835.] Improvements in Science. 195

exposure to the air is converted into the peroxide salt. The
latter is a black flocky precipitate, soluble in caustic am-
monia, and giving a dark colour to the solution. After
evaporation to dryness, a dark extract looking mass remains,
from which water dissolves a neutral double salt, and leaves
a basic oxide salt. Caustic potash likewise dissolves the
perapocrenate of iron, but a precipitate soon subsides, the
apocrenate of potash being dissolved in the solution, and a
basic salt separating. The solution may be freed completely
from iron, by passing a current of sulphuretted hydrogen
through it, but in no other way can the iron be entirely
precipitated.

Croconate of Potash may be formed by passing carbonic
oxide through a glass tube over fused potassium. When
exposed to the air the compound inflames with explosion,
and dissolving in water, and affording, by evaporation, long
prismatic needles of croconate of potash. It consists of

Carbon . . . 27-83
Oxygen ... 29-17
Potash . . . 43-00

100-00
Vermilion. — According to Wehrle, vermilion similar to
that of China can be made by the following process : — Sublime
common vermilion, in very fine powder, with the hundredth
of its weight of sulphuret of antimony, then digest the subli-
mate with the sulphuret of potassium, and afterwards with
muriatic acid, and lastly, with J per cent, of gelatine, dis-
solved in water ; wash and dry it ; a very small portion of
sulphuret of antimony is sufficient to impart to the vermilion
a beautiful crimson colour. (Poggendorff, Ann. xxvii.)

Potash Cyanide of Iridium. — This salt, which crystallizes
in long four-sided prisms, resembling gypsum, was obtained
by Mr. Booth of Philadelphia, by heating a mixture of
anhydrous potash cyanide of iron with powder of iridium.
The salt is colourless, soluble in water, insoluble in alcohol,
is not precipitated by muriatic acid, and contains no water.
By heating it becomes black, and, if the heat is pushed
farther the iridium separates.

o2

196 Notice of some Recent [March

VEGETABLE BODIES.

Sugar of Secale Cornutum, (Jahresbericht, 1834, 275.) —
Wiggers describes a species of sugar obtained from this
fungus, by treating it with water and alcohol, which crystal-
lizes in four-sided prisms. It is transparent and colourless,
soluble in alcohol and water, insoluble in ether. Forms
oxalic acid when nitric acid is poured on it, but does not
decompose by boiling the acetate of copper. It is very
similar to the mushroom sugar, only the latter crystallizes
in right angled prisms.

Starch. — The French chemists have been much engaged
with investigating the composition of this important sub-
stance. Their exertions deserve praise, for it is quite obvi-
ous that an accurate knowledge of its nature must precede
any great improvement in the conversion of its elements
into several important luxuries of life. M. M. Payen and
Persoz describe a substance procured from it to which they
apply the term diatase, possessing very powerful properties.
It is procured by bruising in a mortar fresh sprouted barley,
moistening it with half its weight of water, and submitting
it to pressure. The liquid which separates is mixed witn a
quantity of alcohol sufficient to destroy its viscidity, and
precipitate the azotized matter, which is separated by filtra-
tion. The filtered solution precipitated by alcohol affords
impure diatase, which is purified by three additional solu-
tions in water and precipitations. It is then collected on a
filter, and dried in a thin layer on a plate of glass by a
current of hot air, and lastly, pulverized and placed in
well stoppered flasks. Diatase has no action upon the
fibrous matter, inuline, gum-arabic, lignine, albumen, glu-
ten, tannin, or animal charcoal, but upon fecula it possesses
a most wonderful action, dissolving two thousand times its
weight of fecula in four times the weight of water, at a
temperature between 149° and 161°.

The fecula, according to the same chemists, consists of
99* 5 parts of a substance which they term amidone, and 0-5
fibrous matter. Amidone is procured by boiling for some
minutes a mixture of one part of fecula in 100 parts of
water, passing through a double filter, evaporating rapidly
and drying it in thin slices. By taking it up with cold
water, filtering, evaporating, and drying, the substance is

1835.] Improvements in Science. 197

obtained, mixed with some impurity, which may be removed
by digestion in cold water, and solution in hot, at the tem-
perature 176°, and drying it in vacuo after repeating the
process several times. Amidone is insipid, neutral, colour-
less, diaphanous, elastic, absorbs moisture from the atmos-
phere ; dissolves in water of the temperature 149°, but is
not acted on by cold water unless the two be agitated
together, when a notable portion is taken up. It is insoluble
in alcohol, which extracts some essential oil, and precipitates
it from its aqueous solution. If a solution of tannin be
poured into an aqueous solution of amidone, a copious milky
precipitation ensues, which is re-dissolved by an excess of
the latter. Iodine forms with it a blue compound, which
is insoluble in water below the temperature 149° ; gelatinous
alumina, animal charcoal, phosphate of lime, and isinglass,
remove it from its mixture in water, and several acids
and salts produce the same effect.

A number of experiments, made by the authors, prove
that the amidone of the fecula and of the incomplete re-action
of diatase only differs in its degree of division. Barytes
forms a white bulky precipitate in a solution of amidone.
Subacetate of lead affords an insoluble precipitate, as well
as lime water.

If to fecula, mixed with five times its weight of water,
we add 0*005 of diatase, at the temperature 158°, the whole
of the amidone is destroyed, as may be proved by the absence
of any action upon adding iodine. It is converted into
sugar and gum, which are distinguished from the substance
from which they were produced, by being soluble in water
and weak alcohol, in not being' precipitated by tannin,
subacetate of lead, or any of the re-agents mentioned.
Alcohol of -816 to -794 does not dissolve them. The gum
and sugar are distinguished from each other by the sugar
dissolving in alcohol of -850, without leaving any residue,
while gum is precipitated by the same agent.

The sugar, by the agency of yeast and heat, is converted
into alcohol and carbonic acid, while the gum of amidone,
under the same circumstances, does not produce alcohol,
but by the action of sulphuric acid it is converted into
sugar. According to Biot, the gum obtained from fecula,
by means of diatase, produces on the plane of polarization

198 Notice of some Recent [March

rotation to the right. The authors propose to retain for it
the term dextrine, or gum dextrine.

The fibrous parts of fecula are kept together by interposed
amidone, and various bodies adhere to this envelope, as
carbonate and phosphate of lime, silica, and essential oil.
If the temperature of the fecula is gently raised in water to
202° the amidone swells and ruptures the envelope, pro-
ducing starch.

The authors conclude with some important deductions
from their experiments. In laboratories, and in rural
economy, they suggest that diatase will be useful for the
analysis of fecula, flour, bread, and different amylaceous
substances, but more particularly, will be found an elegant
method of analysing organic substances. The same sub-
stance presents us with the means of obtaining the dextrine
and fibrous matter free from amidone; of procuring the
latter substance in abundance, and of converting it into
gum and sugar. M. Serres has employed dextrine in the
great hospitals at Paris, as a substitute for gum-arabic,
with success, as it is destitute of the insipid taste of that
substance,

M. Guerin Varry has obtained very different results from
his analysis of starch, which by no means hold out to us the
same prospects, but, as great care seems to have been em-
ployed on both sides, we do not hesitate to give place to the
experiments of each, as we consider the subject still clouded
with a few ambiguities.

We confess, however, that Varry's reasons for considering
the substances which he describes as distinct, are far from
being conclusive.

Amidine* forms, according to M. Guerin Varry, one of
the constituents of starch. The method of obtaining it is
to boil, for a quarter of an hour, one part of the fecula of
potatoes in 100 parts of water, pour the liquid into a deep
vessel, allow it to stand till the tegumentary matter is
deposited, decant the fluid, filter it, and evaporate it by slow
boiling, to the consistence of a syrup. The residue is then
to be thrown on a linen cloth, which retains the amidine,
and allows a liquid to pass, which on evaporation at a
temperature below 212°, still deposits amidine. To separate

* Ann. de Chim. ch. de phys. lvi. 225.

Water

. 3-00

Ashes

. 0-20

Amidine .

. 96-80

1835.] Improvements in Science. 199

this it is necessary to filter again and evaporate, and this
treatment should be repeated four times. A liquid is thus
obtained, which, on evaporation to dryness, leaves a residue
completely soluble in cold water. This new solution is
deprived of its colour by animal charcoal, purified and pre-
cipitated by alcohol. The precipitate is thrown on a filter
and washed with alcohol at the temperature 176° ; it is then
dissolved in the least possible quantity of hot water, and the
liquid submitted to a gentle heat. The substance thus
obtained consists of

Oxygen . . 53*15
Carbon . . 39*72
Hydrogen. . 7*13

100*00
It possesses a slightly yellowish colour when dry ; white
when hydrous, and is destitute of taste and smell. In thin
portions it is transparent, and is easily reduced to powder.
M. Biot found, on examining an aqueous solution of amidone,
that it produced upon the polarized rays of light a deviation
towards the right three times as great as cane sugar. When
heated in the air or in vaccuum, it fuses, swelling up, with-
out volatilizing. Cold water dissolves it completely, be-
coming very mucilaginous, but it is more soluble in hot
water. It is insoluble in alcohol and sulphuric ether. It
adheres so powerfully to the porcelain vessels in which it is
evaporated, that, in Varry's experiments, the glaze was
frequently removed although great precautions were em-
ployed. The aqueous solution becomes acid in some days.
Nitric and muriatic acids produce in the cold with amidine
solutions which are coloured strongly blue by iodine. It is
not so soluble in sulphuric acid. Its solution in potash,
when neutrallized by an acid, is coloured blue by iodine,
which detects the presence of amidine in a solution containing
but a minute quantity of it. Nitric acid converts it into
oxalic acid ; 100 parts of amidine and 250 parts of sulphuric
acid, at C 150°, affords 95*80 parts of anhydrous sugar.
The dextrine of Biot and Persoz appears to be an impure
substance containing amidine.

Fibrous amidine (amidine tegumentaire ) is procured by
boiling one part of fecula with 200 parts of water, for a

200 Notice of some Recent [March

quarter of an hour, and allowing the fibrous matter to be
deposited. The supernatant liquor should then be decanted,
and the fibrous matter again boiled with the same quantity
of water, and for the same length of time. This treatment
is to be continued until the filtered liquid, after evaporation
to dryness, leaves no residue, which is turned blue by iodine.
The matter is then dried by a moderate heat. When dried
at a temperature below 212° it possesses a slightly yellow
colour, and presents the appearance of small pellicles, mixed
with small lumps, easily pulverized. It is destitute of taste
and smell, and has no action on test paper. In an aqueous
solution of iodine a fine blue colour is occasioned when this
substance is introduced, which disappears by heating the
solution up to a temperature of 194°, but re-appears on
cooling. When kept for 100 hours in 10,000 times its
weight of boiling water, it is not converted into globules,
as has been stated by Raspail, Biot, and Persoz. It is
insoluble in cold and boiling water, alcohol, and sulphuric
ether. In contact with water it swells, becomes white and
elastic ; 100 parts of insoluble amidine, gently heated with
800 parts of nitric acid, produce 25*46 parts of anhydrous
oxalic acid. If 1 part amidine is digested with 2 J sulphuric
acid at 150°, after twelve hours a syrup is obtained, which,
when boiled with 200 parts of water for two hours, is con-
verted into sugar of starch and vegeto sulphuric acid.

Varry finds the composition of fibrous amidine and woody
fibre, or lignine, almost identical. The constituents of these
substances are

Oxygen. Hydrogen. Carbon.
Fibrous Amidine 40'67 6-59 52-74

Lignine .... 41-78 5-69 52-33*

Hence, I think there is very great propriety in his query.
Is not fibrous amidine merely woody fibre combined with a
small quantity of amidine, which exhibits an action on
iodine 1 The author, however, is rather inclined to consider
these substances as different, and to explain their similarity
on the principle of isomerism, a term which, like that of
nervous in medicine, is now employed on the Continent to
explain all difficulties in reference to analogous compounds.

* By the analysis of Gay, Lussac, and Thenard.

1835.] Improvements in Science. 201

Varry describes a soluble amidine which he considers to be
fibrous amidine held in solution by amidine.

Starch, he states, is therefore composed of 2*96 parts of
fibrous amidine, and of 97*04 parts of a soluble substance
which contains an insoluble matter, identical with fibrous
amidine, and a soluble matter or amidine. This is to the
soluble amidine as 60*45 to 39*55.

Lichenine, is the name which M. Varry gives to the
soluble part of the lichen Islandicus, (cetraria Islandica.)
He prepares it in the manner indicated partly by Ber-
zelius, viz : allowing the lichen to remain twenty-four
hours in contact with water and potash of commerce,
in the proportion of 1 lb. lichen, 18 lbs. water, and 1 oz.
potash; the liquid becomes brown, the lichen is placed
on linen and then macerated with a new quantity of water,
and this is continued till it becomes bitter and alkaline.
The lichen is boiled with 9 lbs. of water down to §, the hot
solution is passed through linen, and the residue expressed.
Varry treats this residue twice with three times as much
water as the lichen employed. The jelly thus prepared
was dissolved in boiling water, and passed through a filter.
The solution was precipitated by alcohol ; the precipitate
re-dissolved in water at 212°, and the liquid evaporated to
dryness by heat. When thus obtained lichenine is yellowish
when dry, colourless when hydrous. It is destitute of taste
and smell, transparent in thin portions, and is not easily
pulverized. In cold water it swells, and scarcely dissolves
in this fluid at the ordinary temperature ; but is completely
soluble at 212°, and forms with it a very thick mucilage.
It colours iodine blue, but has not such a powerful effect as
an equal quantity of amidine. From its aqueous solution
it is precipitated by alcohol and sulphuric ether.

Subacetate of lead precipitates it abundantly, insoluble
in cold water, but soluble in a few drops of acetic acid. An
aqueous solution becomes acid by standing, evaporated at
a temperature below 212°, pellicles form on the surface,
which are completely soluble in boiling water. 100 parts of
lichenine at 150°, and 250 sulphuric acid produce 93*91 parts
of anhydrous sugar. Nitric acid by its action on lichenine
produces no mucic acid ; hence, there is no arabine pre-
sent in it.

202 Notice of some Recent [March

M. Varry has made an interesting observation in refe-
rence to the action of this acid upon lichenine, by which
oxalic acid may be formed at a much cheaper rate than it
is at present. He digested 100 parts of lichenine with 600
parts of nitric acid of sp. gr. 1*34, and at the end of 28 days
formed a quantity of hydroxalic acid ; this is easily converted
into oxalic acid, for if the temperature is raised from the
ordinary heat of the atmosphere to 140°, crystals of oxalic
acid are deposited equivalent to 48*17 parts for 100 liche-
nine. The composition of lichenine is

Oxygen . . . 53*43
Carbon . . . 39*33
Hydrogen. . . 7*24

100*00
being analogous to amadine.

Picrolichenine. (Jahresbericht, 1834, 319. J — In the
Variolaria amara Alms has discovered this substance which
crystallizes and communicates to that lichen its bitter
taste. The lichen is boiled with rectified spirits, the solu-
tion distilled to three-fourths, and the remainder allowed
to evaporate spontaneously. In the course of a week,
picrolichenine separates in crystals. These can be most
effectually separated from the thick mother liquor by
treating them with caustic potash ley, dissolving them in
alcohol and crystallizing. The crystals are in the form of
transparent colourless four-sided double pyramids with
rhombic bases, destitute of smell, but possess a strongly
bitter taste. Sp. gr. 1*176. Melts at 212°. Gives no trace
of ammonia by dry distillation, but the usual products.
Insoluble in cold water, slightly so in hot water. Soluble
in alcohol, from which solution, it is precipitated by water
in flocks. It is dissolved also by ether, volatile and fat
oils, ammonia, sulphuric and acetic acids. From the two
latter, it is precipitated by water. Alms recommends it in
small doses as an efficacious remedy in intermittent fever.

Ergotine, (Berzelius Jahresbericht, 1834, 319.) — Wiggers
has extracted a principle from the secale comutum, which
he terms ergotine. The ergot of rye is treated with ether
and alcohol, and the solution evaporated. The ergotine
remains in the form of a reddish brown powder. By heat-

1835.] Improvements in Science. 203

ing it gives a peculiar smell, and tastes aromatic and bitter.
It is neutral, insoluble in water and ether, soluble in alco-
hol, from which solution it is precipitated by water in ^
reddish brown flocks. By chlorine it is bleached. By
sulphuric acid dissolved, and again precipitated by water.
Caustic potash, but not carbonate of potash, dissolves it.
It is decomposed by nitric acid, but the product is nether
oxalic nor mucic acids.

Cerine Ceraine and Myricine. — Ettling ( Ann. der Phar-
macies ii. 265.) obtained cerine from wax by alcohol. It
was crystalline, colourless, and consisted of, Carbon 78*862.
Hydrogen 13*488. Oxygen 7*647. From the cerine, ce-
raine was formed by drying and pulverizing the mass,
treating the margaric salt with alcohol, and afterwards the
residue with water, and then boiling in dilute muriatic acid,
evaporating to dryness, boiling in alcohol and allowing
crystals to form by cooling. The crystals melted on the
sand bath to free them from moisture yielded, Carbon
80*44. Hydrogen 13*75. Oxygen 5*81.

Myricine, or the portion of wax insoluble in alcohol of
0*833 was dissolved in boiling absolute alcohol ; after cool-
ing, the product deposited was melted and analyzed. It
gave Carbon 80*01 . Hydrogen 13*85. Oxygen 6*14.

Principle in Sarsaparilla. — According to Thubery a cry-
stalline substance exists in the sarsaparilla root which is
taken up by alcohol. 10 pounds of the root contain 3 oz.
1 dr. of the substance which is colourless and tastless, soluble
in alcohol and water. On charcoal it burns with the smell
of benzoin.

Strut hiin, (Jachresbericht, 1834, 316.) — Bley has obtained
from the root of the gypsophila struthium, commonly termed
radix saponariae levanticae, a substance which he terms/
Strut hiin. The bruised root was freed from oily matter by
ether, and afterwards digested in absolute alcohol This
solution was distilled in the water-bath till the liquid
amounted to a small quantity, and was then evaporated in
the air. By cooling, struthiin was deposited in white
flocks, which, when dry, form in yellow pieces. Struthiin
is destitute of smell, has a sweetish, mucus taste. It is not
volatile, but is inflammable, and burns with flame. It is
soluble in water, which it makes frothy like a solution of

204 Notice of some Recent [March

soap. It is insoluble both in hot and cold absolute alcohol,
but somewhat soluble in alcohol containing water, insoluble
in ether. It is decomposed by hot sulphuric acid, but is
not dissolved by muriatic acid. The root contains \ per
cent, of struthiin.

Eight months after the experiments of Bley were made,
M. Bussy published an analysis of the same root, and
termed the principle saponin, which he found to consist of

Carbon . . . 51'
Hydrogen. . . 7*4
Oxygen . . . 41*6

100-0

but he observes that this is merely to be considered an
approximation.

Various Vegetable substances, {Ann. de Chim. i. 197.)—
Pelletier has analyzed a number of vegetable substances,
and obtained the subsequent results : —

Carbon. Hydrogen. Oxygen.

1. Oily matter of opium . 72-39

2. Caoutchouc of opium . 87-89

3. Santaline 75-03

4. Olivile 63-84

5. Sarcocolline, Azote. 57*15

6. Piperine 4-51 70'51

1 . The oily part of opium which remains after the evapo-
ration of the ether solution, is mixed with narcotin and
caoutchouc. From the latter it may be separated by
alcohol, and from the former by muriatic acid.

3. Constitutes the colouring matter of sandal wood.

4. The sap of the Poenea mucronata produces sarcocoll,
and from the latter the sarcocolline was extracted, first by
heating it with ether, and then with absolute alcohol.

Benzine. — When benzoate of lime is subjected to distilla-
tion at a temperature of 300°, (572° F.) a brown oily matter,
denser than water, comes over, and carbonate of lime re-
mains. If this oil be distilled on the sand bath, a limpid
oil passes over, which is lighter than water, and possesses
the smell of bitter almonds, and boils at 82°, (179° F.) By

11-82

15-78

12-11

—

6-37

18-60

8-06

28-10

8-34

34-51

6-80

18-28

1835.] Improvements in Science. 205

continuing the process water is produced, and a second oil,
which boils about 250°, (482° F.)

1. It holds in soluticfti a third substance, which has a
white colour, and crystalline structure. It is naphthaline.
The oil, at 20°, assumes the appearance of an emulsion, and
is termed by Peligot benzone, in conformity with acetone
and margarone. Benzone consists of

Carbon . . . 86-5
Hydrogen . . 5*4
Oxygen ... 8*1

100-0

It is a thick oil, colourless when pure, but generally pos-
sesses an amber tint, with a slightly empyreumatic smell,
and it is lighter than water. It is not attacked by nitric
acid and potash, but is decomposed by sulphuric acid.

2. The naphthaline is perfectly white, fuses at 78°,
(172° F.), boils at 210°, (410° F.), and consists of

Carbon . . . 93*86
Hydrogen . 6*14

100-00

3. The oil procured by the gentle distillation is colour-
less, lighter than water, boils at 82° (179° F.) and possesses
an aromatic smell. It consists of

Carbon . . . 92-45
Hydrogen. . . 7-55

100-00
and is therefore a bicarburet of hydrogen.

Peligot conceives, however, that if the decomposition of
the benzoate of lime could be effected at a moderate tem-
perature, nothing but benzone would be produced, and
carbonate of lime would remain. The formula for benzoate
of lime according to the experiments of Wohler and Liebig
will be : 14 C + 6 H + 40 + C.

If we take from this an atom of carbonate of lime, we
have remaining for the composition of benzone,

13 C + 6 H + 2 O, {Ann. de Chim., lvi, 59.)

Mitscherlich# has examined the same substance under

* Pogg. Annal. xxix. 231.

20G Notice of some Recent [March

the name of benzine, and considers it the base of benzoic
acid, which is therefore a combination of benzine and car-
bonic acid. •

Peligot states that benzone distilled with quick lime
produces carbonate of lime and naphthaline, and that in
distilling hydrous benzoic acid with lime in excess, bicar-
buret of hydrogen is the only product.

JVitro-benzide, is the name given by Mitscherlich to the
product of the action of fuming nitric acid upon benzine.
It is a yellowish coloured substance, possessing a sweet
taste and peculiar smell somewhat between that of bitter
almonds and oil of cinnamon. Its spec.grav. is 1*209. Its
boiling point is 415°. At 37° it begins to solidify, and cry-
stalline needles are observed. Sulphuric acid decomposes
it. It detonates when heated with potassium. It is almost
insoluble in water, and completely so in ether and alcohol.
Concentrated nitric and sulphuric acids dissolve it easily,
It consists of

Carbon . . . 58*53
Hydrogen. . . 4*08
Azote . . . . 11-20
Oxygen . . . 25*99

99*80
Sulpho-benzide, is procured by the following process. Ex-
pose benzine to the action of anhydrous sulphuric acid, or
acid of Nordhausen until a thick liquid is produced, which
dissolves completely in a little water. Saturate the acid with
barytes, and decompose the salt of barytes in solution with
sulphate of copper ; after evaporation, sometimes crystals
of the copper salt are obtained, and sometimes sulpho-ben-
zoate of copper ; and in addition, a crystalline powder sepa-
rates when the liquid is reduced to dryness. This substance
is very slightly soluble in water and may be completely
freed from the acid which it retains by repeated washing
in the water ; but to have it in a state of absolute purity,
it should be dissolved in ether, the solution filtered, eva-
porated, and the resulting crystals subjected to crystalliza-
tion. At 212° it becomes a transparent colourless liquid,
and boils at a temperature between the boiling points of

1835.] Improvements in Science. 207

mercury and sulphur. It is destitute of taste and smell,
insoluble in alkalies, soluble in acids, from solutions in
which it is precipitated by water. With sulphuric acid it
forms a peculiar acid, which forms a soluble salt with ba-
rytes. It suffers no alteration when distilled with nitrate
or chlorate of potash. It detonates with saltpetre at a red
heat, and also with chlorate of potash at a very high tem-
perature. At the ordinary temperatures chlorine and bro-
mine have no action on it, but at the boiling temperature
chloride of benzine is formed, and in this way the quantity
of oxygen contained in it was determined. It is composed
of Carbon . . . 66.42

Hydrogen . . 4*52
Sulphur . . . 14-57
Oxygen . . . 14*49

100-00*
Madder is such an important article in the art of dye-
ing, that its proper culture and natural history have justly
attracted the attention of chemists. Schlumberger, a Ger-
man, has lately published an account of a series of experi-
ments, which he has made for the purpose of determining
the causes of the difference between the madder of Alsace,
and that raised in Avignon, from which he has inferred,
that carbonate of lime is indispensable, that, when we
wish to dye red and violet colours with madder upon
cotton with an alum or iron mordant, if we use Avignon
madder the addition of lime is in general unnecessary, be-
cause it naturally contains carbonate of lime, except in a
few instances where the plant has been raised on a soil
containing little calcareous matter; while the Alsace mad-
der which contains only a small portion of lime, although
it can produce as deep a shade as the former, yet does not
form so permanent a colour ; but when lime has been added,
the dye is equal to that of Avignon. Besides lime, there
are several other substances which produce standing colours
with madder These are in the order of their power, car-
bonate of lime being the best, phosphate of lime, carbonate
of magnesia, hydrous protoxide of lead, protoxide of zinc,
carbonate of zinc, protoxide of manganese, hydrous per-

* Ann. de China, lrii. 85.

208 Notice of some Recent [March

oxide of manganese, hydrous protoxide of cobalt, acetate of
lime, and phosphate of cobalt. The Avignon madder loses
its permanence when treated by acid which dissolves the
salt of lime.

M. Robiquet, who along with Colin and Logier has
been paying much attention to the subject, although
he does not deny the truth of the facts to a certain
extent, brought forward by the German chemist, ascribes
them to a different cause. He affirms, that lime is not
necessary for obtaining permanent madder colours, and
indeed, that its presence impedes good dyeing. He has
found in madder two colouring matters, alizarine and pur-
purine, which vary in their relative proportions, according
to the nature of the soil, the cultivation, climate, and age
of the root. In most of the acids, alizarine is insoluble, so
that when an acid is present, this colour cannot be fixed.
The Avignon madder contains no free acid, while the Alsace
madder does, as is apparent from its yellow colour. The
latter contains much purpurine, and is therefore, better
fitted than the Avignon madder, for dyeing lake colours,
the agent necessary being purpurine. A hot solution of
alum dissolves the purpurine, and does not attack the
alizarine, which is remarkable, because, when the latter
has once combined with alumina, the affinity is very strong.
Robiquet, infers therefore, from these circumstances, that
it is not the same colouring matter which becomes alter-
nately fixed or fugitive, according to the presence or absence
of chalk, but that it is owing to the existence in the madder
of two distinct colouring matters, one of which, the purpu-
rine is soluble in acids, and can therefore, readily be
brought in contact with the mordant, while the other re-
quires neutralization, previous to solution. Robiquet found
that during boiling, carbonic acid was extracted from mad-
der, which he considers as being either present naturally,
or as being formed by the alteration of some of the prin-
ciples during the process. At a temperature of about 300°,
not only carbonic acid, but acetic acid also, without oil was
discharged. Robiquet conceives, that the fine colour of
Turkey red is owing to the combination of the two colouring
matters, and that the fixation of the purpurine is to be
ascribed to the oil, ( Ann. de Chim. lvii. 70.)

1835.] Improvements in Science. 209

Oil of Wax. — Ettling has examined the oil of wax after
freeing it from paraffine and margaric acid. Red oil of wax
was distilled with four parts of water to one half. It was
then digested with potash, which removed a brown matter,
and afterwards distilled and rectified with muriate of lime.
It became pale-yellow ; sp. gr. 0*7502; boiling point 137°
(278° F.) It consists of

Carbon . . . 85*535
Hydrogen . . 14*224
Oxygen . . . 0*241

Annalen der Pharmacies 100*000

Products of the decomposition of alcohol, by peroxide of
manganese and sulphuric acid. {Ann. de Pogg. xxviii. 508.)
C. G. Gmelin announced that when alcohol is distilled with
peroxide of manganese and sulphuric acid, formic acid was
formed, but Dbbereiner disputed the fact. M. L. Gmelin,
to settle the matter, distilled two parts of alcohol with
four of water, two of sulphuric acid, and two peroxide
of manganese. He obtained as the product, pure water,
and a substance possessing the smell of naphtha, containing
much formic acid, with a little acetic acid. When no
water is added to the alcohol a small quantity of formic
acid only is formed, and the residuum possessed the smell
of benzoine. He did not, however, detect the presence of
benzoic acid.

Pyroxilic Spirit, by M. S. Leibig, {Journ. de Pharm. v. 32.)
In distilling wood vinegar, wood spirit is obtained, which
strongly resembles alcohol, but is very impure. To purify
it after rectification, it is saturated with chloride of lime,
which it dissolves, it is then allowed to settle. An empy-
reumatic oil which it contains, separates and swims on the
surface. It is distilled a third time, and in order to separate
the water it is rectified several times over chloride of cal-
cium. Pure wood spirit is a colourless fluid with the pene-
trating smell of ether, possessing the taste of pepper. It
boils at 140°. Its sp. gr. is 0*804 at 64J°. It burns with a
blue dim flame. It consists of

Carbon . , . 0*5382 3 atoms.

Hydrogen . . 0*1097 5 „

Oxygen . . . 0<3510 1 „

VOL. I. P

210 Notice of some Recent [March

and therefore may be considered as formed of

Ether ... 1 atom.

Oxygen. . . 1 „
Formation of Ether, (Poggendorff, xxxi. 273.) — Mitscher-
lich, in carefully investigating the formation of ether, has
observed that sulphuric acid, by its affinity for water, pro-
duces the compound of one volume of hydrogen gas, and
one half volume of oxygen gas, forming water* It appears
also that water passes over with the ether, and that the
sulphuric acid has previously combined with the water.
Alcohol will not be converted into ether when treated with
other substances which have a greater affinity for water
than dilute sulphuric acid. If a concentrated solution of
the acid is heated with alcohol to the temperature of 140°,
(252° F.) the point at which ether is formed, no trace of
ether can be detected in the liquid which passes over.
Ether is formed in the production of sulphovinic acid, by
the action of sulphuric acid on alcohol. When sulpho-
vinate of potash is mixed with lime at a temperature above
200°, (392° F.) sulphuric acid, salts, and alcohol are formed,
with some oil of wine. Similar decompositions and combi-
nations occur on the contact of numerous substances, as the
conversion of a species of sugar into alcohol and carbonic
acid ; the oxidation of alcohol when it is converted into
acetic acid ; the conversion of starch into sugar, by boiling
it with sulphuric acid. When combinations of ether with
acids, as acetic ether, are treated with caustic potash,
acetate of potash and alcohol are the products.

Creosote. — Hubschmann has simplified the process for
preparing this substance, which at first promised to be of so
much importance both as a medicine and antiseptic. (Ann.
de Chim. lvii. 105.) He distils tar oil as it is afforded in
the process for obtaining pyroligneous acid, in a large retort
with a small portion of sand, in order to increase the num-
ber of bubbles which are formed during ebullition, and thus
diminish its violence. What comes over at first, consisting
of eupion, acetic acid, &c, is laid aside, but whenever a
liquid begins to appear which falls drop by drop into the
receiver, the latter is to be changed, and the distillation
continued until the mass becomes foamy. The product
of the distillation is then poured into a vessel with about

1835.] Improvements in Science. 211

double its volume of water, to which a sufficient quantity of
sulphuric acid has been added to enable the fluid containing
the creozote to swim on the surface. The liquid is then
boiled for some minutes. After cooling, the colourless
liquid below is separated, and the brown oil is rectified in
a retort. The product may again be subjected to the same
treatment with sulphuric acid and water. The colour is
still brown, but after being separated from eupion it is
pale-yellow.

In order to separate the eupion, the rectified product
should be dissolved in a solution of caustic potash, according
to Reichenbach's method.

The supernatant oil is separated, the ley heated, and
after cooling, it is converted by sulphuric acid into a solu-
tion of sulphate of potash and creozote, which swims on
the surface. The latter may be obtained colourless, by
washing it in water mixed with a slight excess of solution
of potash, and then distilling it. Hubschmann considers
that, as an agent in medicine, its powers have been greatly
overrated, and that the only use which ought to be assigned
to it is its application for ameliorating the pain of carious
teeth.

Picamare, [pix amara] {Schweigg. Jour, lxvii.) — Reichen-
bach gives this name to a substance obtained from tar-oil,
which, by repeated distillation, being brought to a sp. gr.
of 1*08, is mixed with caustic potash of sp. gr. 1*15, in the
proportion of 1 part to 8. In the course of two days a
compound of picamare and potash is formed, which may be
decomposed, and the picamare obtained by acids. Creosote
remains in the mother liquor. Pure picamare is colourless,
greasy, with a strong smell, inflammable, and bitter tasted,
boiling at 120° C, (248° Fahr.) It is insoluble in 1000 parts
of water, to which it imparts a bitter taste. It dissolves in
any proportion in ether, sulphuret of carbon, and petro-
leum, and does not combine with paraffine and eupion. It
unites with chlorine, iodine, bromine, phosphorus, sulphur,
and selenium, and dissolves in sulphuric and nitric acids.
It . crystallizes immediately with all alkalies, even with
ammonia.

Paraffine (parum affinis.) — When tar from beech wood is
distilled to dryness, three liquids pass over into the receiver,

p2

212 Notice of some Recent [March

in the upper part alight tar-oil, in the middle an acid liquid,
and at the bottom a heavy oil. The latter is to be distilled
a second time, and when the matter becomes scaly, the
receiver should be changed, and the heat increased until
the residue becomes black and thick. In the receiver,
which is filled with a yellow vapour, an oily liquid appears,
in which spangles of paraffine are observed. From this
liquid, which, if it does not exhibit the characters described,
must be again distilled, the paraffine may be obtained by
the following methods : — Mix it with from six to eight times
its weight of spirit of wine, (sp. gr. -837.) In a short space
a thick liquid separates, which must be again washed with
spirit of the same strength, till it is converted into colour-
less thin portions, then these are to be dissolved in hot
absolute alcohol, and the solution allowed to cool. This
process may be repeated until a snow white precipitate of
paraffine is obtained. (Pogg. Ann.)

ANIMAL SUBSTANCES.

Structure of the Nerves and Brain, {Pogg. Ann. xxviii.
463.) — According to Ehrenberg the cerebral mass consists
of parallel tubes expanding in a varicose manner, and con-
verging to the base of the brain. The brain is a system of
capillary vessels similar to the nerves. The nerves of sen-
sation and the sympathetic nerve consist of soft, cerebral,
medullary matter ; the latter surrounded by nervous tubes.
These may be termed jointed nerves (nerves of sensation? )

All other nerves consist of tendinous, cylindrical tubes,
formed of a peculiar medullary matter, which may be called
tubular nerves, (nerves of motion ?)

The nervous medullary matter is absent in the brain
and jointed nerves.

The structure is the same in man and all vertebrated
animals. In the inferior vertebrated animals, the soft,
cerebral matter is observed in small quantity, while the
tubular substance is abundant.

In the vascular net of the cortical substance of the brain,
large globules are scattered, which are proportional to the
globules of the blood.

By the aid of powerful instruments, Krause has been
able to observe in the cerebral and nervous substance small

1835. Improvements in Science. 213

fibres, which partly run in a winding manner, parallel
to each other, and partly cross each other obliquely in
such a way that they can be traced through their cross-
ings. The first appear especially in the longitudinal clus-
ters in the base of the brain, the latter in the limits of the
white and gray substance of the brain. These fibrils have
generally a diameter of J^o t0 64o °f a lme> Dut at intervals
they swell into knots which are 2Jo in thickness, and consist
of an extensive, tough, transparent substance, soluble in
water, and of spherical, slightly transparent, white, ner-
vous globules, which possess a diameter of from 6}0 to ^
being roundish or oblong. In the thin fibrils the globules
lie in one row, but in the thicker fibres two or more are
arranged abreast without forming regular rows. In many
parts of the nervous substance, as in the slices of the cere-
bral mass, few or no parallel fibres are detected, while
globules either of a cylindrical or elliptical form may be
observed. In the grey matter the globules are heaped to-
gether, and occasionally may be noticed transverse fibres,
or their curved oblique courses traced. The knots of the
fibrils Ehrenberg considered to be bladders. Krause, how-
ever, concludes that the fibrilli are solid cylinders and not
tubes, because in the globules magnified 1000 times, he saw
an outer border of the circuit, and on the cut edges of the
brain and nerves which contain longitudinal and transverse
fibrils, and therefore must be cut through. He never could
observe light by magnifying to the highest degree, and by
every possible change of illumination.

He considers water an improper medium through which
to view the globules, because, as in the blood, their form is
altered by that fluid, and he recommends the fresh serum
of the blood and water holding in solution albumen.

Professor Ehrenberg, in answer to Krause, states that he
has made observations with and without water upon the
nervous substances, and by the aid of an instrument much
more powerful than that employed by Krause, and has found
them steady, and still adheres to the opinion that the fibrilli
are tubes.

Combination of albumen with metallic oxides, albumen, and
chloride of mercury, by F. Rose. — The precipitate by albu-
men in a solution of chloride of mercury is soluble in an

214 Notice of some Recent [March

excess of albumen, but insoluble in an excess of chloride
of mercury. If the precipitation is produced by an excess
of chloride of mercury, the solution passing through depo-
sits by evaporation crystals of chloride of mercury, which
have a yellowish colour,from some dissolved albumen, but
very inconsiderable in quantity.

In ammonia the moist precipitate is soluble, but after
some time the solution becomes muddy, and is increased by
the application of heat.

In potash the moist precipitate dissolves easily, the solu-
tion depositing gradually black metallic mercury.

By acetic acid also the precipitate is dissolved, and is not
altered by boiling. Sulphate of copper added to the solu-
tion produces a green, and chloride of iron a yellowish
brown precipitate.

According to Bostock, the precipitate is a combination
of the constituents of muriate of mercury with albumen,
but Orfila considers it a compound of albumen and chloride
of mercury, as its solution was coloured black by a free al-
kali. This, however, was no proof, because all organic
substances which are not volatile, reduce mercury from
oxide of mercury or solution of chloride of mercury, when
a free alkali is present.

From the experiments of F. Rose, it appears that this
precipitate is not a combination of chloride of mercury with
albumen, but of albumen with the oxide of mercury. The
same result took place with the serum of the blood. A
solution of the red matter of the blood yielded with an ex-
cess of the chloride of mercury a red precipitate, which
consisted of a combination of the colouring matter with
oxide of mercury, albumen, and sulphated protoxide of
copper.

An excess of a solution of sulphate of copper completely
precipitates albumen of a green colour, which is dissolved
by an excess of albumen. Ammonia dissolves the precipi-
tate, forming a dark blue solution. Potash produces a vio-
let solution. A solution of carbonate of soda dissolves it
completely, occasioning a violet colour. Potash throws
down the copper, but in the filtered liquid no sulphuric
acid can be detected.

If the precipitate is heated and dissolved in nitric acid,

1835.] Improvements in Science. 215

no effect will be produced on the addition of sulphate of
barytes. Hence, the precipitate consists of albumen and
protoxide of copper. In one experiment the percentage of
oxide was 1*69, and in another 1*60, affording a very small
saturating power to the albumen. The serum of ox blood
exhibited the same appearances. A solution of colouring
matter of blood produces with sulphate of copper a flocky
reddish brown precipitate, which is a compound of the red
matter and protoxide of copper, containing 1*901 per cent,
of oxide.

Albumen and Chloride of Iron. — By the mixture of the
solutions of these substances a reddish brown precipitate
is formed, which is readily soluble in an excess of ether.

The moist precipitate dissolves easily in ammonia, and
potash has the same action.

Acetic acid and solution of sulphate of copper dissolve it
likewise. In the heated residue of the precipitate with
carbonate of soda, no trace of chlorine can be detected. In
this combination the percentage of peroxide was in one trial
2-799, and in a second 2-887.

Albumen and Sulphate of Zinc. — This precipitate is white
and is dissolved by an excess of either constituent. It is
very soluble in acetic acid, ammonia, solutions of carbonate
of soda and sulphate of copper. In the three first solutions
no trace of sulphuric acid can be detected. Hence, the
precipitate consists of oxide of zinc and albumen containing
2*729 per cent, of oxide.

Albumen combines with many other bases, the most of
which are soluble both in an excess of albumen and of the
salts of the base. (Poggendorff's Ann.)

Colouring matter of Blood. (N. Journal fur Chemie, iv.
314.) — Hembstadt conceives that as sulphur forms one of
the constituents of the blood, and as iron exists in the
colouring matter, the red colour of the blood may proceed
from the presence of the sulpho-cyanate of iron. He states
that the colour of the blood may be imitated by mixing
albumen, water of the blood, or milk with hydro-sulphuret
of cyanogen and a little chloride of iron.

Concretions. — Lassaigne found an elastic concretion in
the lungs of a horse to consist of some fat and fibrine of
the blood.

216 Notice of some Recent [March

He analyzed a tumor from the kidney of a woman, and
obtained an albuminous liquid in which Cholestin was con-
tained.

Wiggers found a concretion from the uterine portion of
a woman's placenta to contain fibrine, with some fat and
albumen 46*1645, phosphate of lime with traces of mag-
nesia 43-6709, carbonate of lime 3*1646, water 7*000.
(Journ. de Chim. Medic, viii. 551 .)

Calculus from the Kidney. — This calculus was found in
the kidney of a male subject, which had been brought to a
dissecting room in Glasgow. The quantity procured was so
minute, that the tests which I could apply were more limited
than could have been wished in the case of this concretion,
which appears to have contained at least traces of xanthic
oxide.

Before the blow-pipe it blackens, giving out an odour of
animal matter, and fuses into a white enamel, very soluble
in nitric acid. When evaporated to dryness the residue
has a fine orange colour, and when boiled with water, it
does not appear to be dissolved, but tinges it of a hyacinth
colour, which is converted into a lemon yellow by the
addition of a little nitric acid. Insoluble in caustic am-
monia. Not sensibly soluble in caustic potash, by which it
is precipitated from the nitric acid solution, the precipitate
not being re-dissolved by adding an excess of potash.

Creatine, (Journal de Chem. Med. viii. 548.) — Chevreul
gives this name (from K^a<; flesh) to a crystalline substance,
which is obtained by heating with alcohol the extractive
residue which remains after the evaporation of the solution
of muscle. A substance remains then mixed with the ex-
tractive matter, from which it may be separated by crystal-
lization. It exists in minute quantity in muscle. It is
colourless, crystallizes like common salt, in cubes, has no
taste, is neutral, insoluble in alcohol, very soluble in water
and nitric acid.

BOTANY.

Botany of Wermland and Dalsland, by C. G. Myrin. —
Dalsland is a small province of Sweden, on the west of
Lake Wener, presenting an undulating surface, and belong-
ing to the primitive formations. Wermland lies rather
north of Lake Wener, and extends as far north as 61°,

1835.]

Improvements in Science.

217

gradually narrowing to a point. Its length is 1 10 miles,
and its greatest breadth 80, but it tapers gradually, and
towards the northern extremity is only a few miles broad.
In both provinces the number of plants observed are of

Algae 125

Musci and hepaticae . 197

Filices 35

Phanerogamae . . . 521

322

556

878

Those peculiar to Wermland = 35
Common 466

501

Peculiar to Dalsland . 55
Common 466

521

The species arranged according to Wahlenberg are in-
cluded in the following table of natural orders :

Composite .

Gramina. .

Calamariae .

Tripetaloideae

Senticosae

Personatae

Caryophylleae

Holoraceae .

Papilionaceae

Verticillatae

Amentaceae

Bicornes . .

Multisiliquae

Siliquosae .

Gruinales .

49
47
43
25
24
24
23
22
21
19
19
18
16
16
15

Umbellatae . .
Campanaceae .
Succullentae . .
Orchideae . . .
Stellatae . . . .
Columniferae .
Sarmentaceae .
Calycanthemae
Asperifoliae . .
Inundatae
Dumosae .
Luridae .
Rotaceae .
Pomaceae

15

12

12

10

8

8

6

6

6

5

5

5

5

5

Gentianeae .
Coniferae .
CoronariaB
Tricoccae .
Rhoeadeae
Aggregatae
Scabridae .
Aroideae .
Spattiaceae
Ensatae . .
Sepiariae .
Trihilatae .
Vepriculae.
Najadeae .

The species of phenogamous plants and ferns found in
these provinces which do not extend to Britain are chiefly
the following : —

Scirpus nanus ; Poa sudetica ; Galium trifidum ; Cam-
panula cervicaria ; Selinum carvifolia ; Allium angulosum ;
Ornithogalum minimum ; Convallaria bifolia ; Juncus arti-
culatus; J. nodulosus; J. supinus ; J. stygius; Polygonum
biforme; P. minus; Pyrola chlorantha; the P. um bellata

218 Notice of some Recent [March

Cucubulus behen ; Silene rupestris ; Alsine rubra ; Sedum
anuum; Sorbus scandica ; Rosa collina; Potentilla norve-
gica; Tormentilla recta; Anemone hepatica, A. vernalis;
Geranium Bohemicum ; Corydalis bulbosa ; Orobus vermis ;
Viciavillosa; Trifoliumagrarium,T. hybridum; Scorzonera
humilis; Filago montana ; Neotna repettis ; Calla palustris ;
Carex chordorrhiza ; C. leporina ; C. heleonastes C. loliacea ;
C. canescens, C. livida; C. globularis; Salix limosa; Blech-
num spicant ; Onoclea struthioptens ; Botrychium rutace-
um ; Lycopodium inundatum. — (Kongl. Vet. Acad. Hand.
1831, 171.)

Dr. Al Bunge has given a list of about 600 plants collec-
ted by him in 1831, principally between the great wall of
China and Pekin, in the Petersburg Memoirs (ii. 75.)
Among them we observe many new genera and species, and
likewise a considerable proportion indigenous to Great
Britain, as the Papaver rhaeas ; Chelidonium majus ; Capsella
bursa pastoris ; Sisymbrium sophia ; Lepidium ruderale ;
Raphanus rhaphanistrum ; Medicago lupulina and sativa;
Pisum sativum ; Pyrus malus ; Epilobium hirsutum ; Daucus
carota ; Apium petroselinum ; Pyrethrum parthenium ; Cicho-
rium intybus ; Hyoscyamus niger ; Solanum nigrum ; Mentha
piperita ; Glaux maritima, Sfc.

Fossil plants in the calcareous green sand of Skania. — Nilsson
describes the remains of four dicotyledonous plants in this
formation. : —

1 . Phyllites (Acer? Cretaceum) folio quinquinervi? venoso.

2. Phyllites (Salix? Wahlbergii) fol oblong vel elliptic
integerr, subundatis costati venosis, venis alternis petiolo
mediocri.

3. Phyllites (Almis ? Friesii) fol osubrotundato elliptico ?
subcrenato costato, venoso, venis alternis frequentioribus.

4. Phyllites (Comptonia ? antiqua) folio sinuato venoso,
in petiolum fere attenuato, lobis integerrimis Monocotyle-
donous.

5. Cannophyllites septentrionalis fol lanceolat? undato
nervis frequentissimis e costa parallele exeuntibus, et an-
gulos acutos formantibus.

6. Cycadites Nilssoni fronde pinnata pinnis 5-6 long lin
lanceolat integerrimis marg subrevolutis ? unnervibus
canaliculato carinatis e petiolo basi dilatato, oblique unila-
teraliter exeuntibus.

1835.] Improvements in Science. 219

Cycadites praecedentes speciei ? Spad linear, elongat sub-
cylindric squam imbric fructum superantibus ovat subro-
tund obtusiusculis integer convex, inferior patulis, superior
adpressis, fructibus inferior, magis explicatis subrotund
depressis convex obtusissimis, arete imbricatis magnitud
lentis superior, multo minor magisque globosis.

Plants in the coal formation of Skania. — Abies St ember gii,
ramulis adscendenti erectis tuberculatis : fol confert tuber-
culis insertis linear, acutiuscul sessil, uninervibus erecto,
patentibus, vel patent, semipollicaribus ramulis paullo an-
gustioribus.

Lycopodites phlegmariformis caule erectiusculo, fol inte-
ger, acutiusculis, erectopatentibus uninervibus (per exsicca-
tionem) transverse lineatis semiamplexicaul, alternis, infe-
rior remotioribus oblong lanceolat, superior imbricat oblong
minoribus.

Potamophyllites? Agarethiana, fol lingulato linear ner-
vosis, integerrimis. — Kongl. Vet. Acad Handl. 1831, 340.

Article IV.
Analysis of Kirwanite. By Robert D. Thomson, M. D.

This mineral, to which it is proposed to apply the name
Kirwanite, in honour of the late distinguished Irish chemist,
is found in the county of Antrim, filling amygdaloidal
cavities in basalt.

The texture is fibrous ; the fibres diverge from a centre,
forming green brushes ; opaque ; about the hardness of sul-
phate of lime. Before the blowpipe per se becomes black,
and partially fuses. Fuses with soda, borax, or salt of phos-
phorus, into a dark brown glass. Sp.gr. 2-941. The com-
position of the mineral is

Silica 40-50

Protoxide of iron . 23*91

Lime 19*78

Alumina . . . . 11*41
Water 4-35

99-95

t220 Dr. R. D. Thomsons [March

which corresponds with 4 atoms Silica

1 ,, Lime
1 ,, Alumina
1 ,, Water.

Hence, its formula is C S + /S + Al S2 + Aq.

Article V.
Chemical Analysis of Wollastonite. By
Robert D. Thomson, M. D.
The term Wollastonite has been applied to a variety of
minerals. Hauy distinguished the table spar or bisilicate
of lime by this name. And the same title has been be-
stowed, it appears, on Zurlite, which is brought from the
Capo de Bove, near Rome, and is described by Remondini,
in the Memoirs of the Academy of Naples.

The Wollastonite of the Castle Hill, Edinburgh, turned
out on analysis to be Prehnite. The other localities where
table spar is said to occur, must therefore, be considered
as doubtful. It would seem proper that the names by
which these minerals have been recognized, should con-
tinue to be attached to them, and that the name of Wol-
laston should be conferred on a distinct species. " I have
been induced," says Pr. Thomas Thomson, " in order to
commemorate the many obligations which mineralogy owes
to Dr. Wollaston, to apply the term Wollastonite, to a
mineral which I believe to be new, and which has a very
close relation to the species, which Hauy designated by
that name," (Edinb. Trans. 1831.)

The following particulars were ascertained with the
assistance of Professor Thomson : —

The mineral occurs in veins, in a green stone which is
brought to Glasgow from Kilsyth, and is found abundantly
on the banks of the Forth and Clyde canal.

It possesses a white colour with a slight shade of green.
Texture fibrous, the fibres being arranged in tufts diverg-
ing from a centre, and thus having the appearance of im-
perfect crystallization. The edges are translucent, and the
lustre inclines to silky. Fracture splintery, and the frag-
ments are sharp edged. Hardness intermediate, between
that of selenite and calcareous spar; sp. gr. from 2*850 to
2*8760. Before the blow-pipe it melts with some difficulty

1835.] Analysis of Wollastonite . 221

into a white enamel with froathing. With borax it fuses
into a bead, yellow while hot, but becoming colourless on
cooling. With salt of phosphorus in excess, it fuses into a
colourless bead, leaving a skeleton of silica. With carbo-
nate of soda, it effervesces and fuses into an opaque bead
with a reddish blue colour.

25 gr. were twice analyzed, by fusion with carbonate of
soda and solution in muriatic acid precipitation by the appro-
priate re-agents. The sum of the constitutents in one case,
(consisting in both of silica, lime, magnesia, peroxide of
iron, alumina and water,) wras 22*050 gr., and in a second
instance, 22*455 gr. It was obvious, therefore, that the
deficiency was owing to the existence of an alkali as a con-
stituent of the mineral.

10 gr. of the mineral were finely pounded, and intimately
mixed in a platinum crucible with 50 gr. carbonate of
barytes, prepared by precipitating the chloride of barium
by carbonate of ammonia, the chloride of barium having
previously had a stream of sulphuretted hydrogen passed
through its solution, to separate the lead which is usually
mixed with that salt as it. is met with in shops.

The mixture was kept at a red heat for nearly two hours.
The decomposed mass was then digested in dilute muriatic
acid. The whole of it dissolved with the exception of the
silica which was thrown on a filter and washed with hot
water. Carbonate of ammonia, and a little caustic ammonia
precipitated the remaining constituents and the barytes.
The liquid from which every thing was separated except
the alkali was evaporated to dryness, and cautiously ignited
in a platinum capsule. What remained proved to be chlo-
ride of sodium. It weighed 1*8 = *72 sodium, which is
equivalent to *96 soda. The constituents per cent, are,

Silica . . .

. 52*744

Lime . . . .

31*684

Soda . . . .

. 9*600

Magnesia . .

1*520

Peroxide of iron

. 1*200

Alumina . .

0*672

Water . . .

2*000

99*420

222 Dr. Andrew Steel [March

Now, we may consider this as equivalent to

26*37 atoms of silica
9* ,, lime

2-4 ,, soda
•5 ,, magnesia
or, considering a portion of the soda replaced by magnesia,
we should have nearly

9 atoms silica
3 ,, lime
1 ,, soda
equivalent to 3 atoms bisilicate of lime
1 atom tersilicate of soda,
and expressed by the symbol 3 C S2 + N S3 ; or we may
consider the magnesia replacing the lime, which would
make the composition of the mineral

4 atoms bisilicate of lime
1 atom tersilicate of soda
with the formula, 4 C S2 + N S3. Whatever view we
adopt, we see that the mineral differs essentially from table
spar, which consists of one atom of lime united to two of
silica, answering to the formula C S2.

Article VI.

On Spirits. By Andrew Steel, M. D.#

Of all the numerous manufactures which this country
possesses, and which have contributed so materially to* her
wealth and influence, there is scarcely one which has
attracted less the attention of men of Science, or in which
the progress of Chemistry has been the means of intro-
ducing so little improvement, as that of Spirits. Whilst
others have been more or less perfected as the nature and
properties of the materials employed or products obtained

* The death of this excellent young man, in December, 1832, from disease
contracted in India, deprived Science of a most promising supporter, society of an
amiable member, and the Editor of an affectionate friend. In order to account
for some allusions which occur in the present article, it is necessary to observe,
that it constituted the first of a series of' papers, which he was preparing to draw
up from original investigation, when the checquered scene of life closed on him
for ever. — " Laevius fit patientia quicquid corrigere est nefas."

1835.] on Spirits. 223

have been more accurately determined, this has remained
nearly stationary.

The subject is undoubtedly a difficult one, from the little
progress that has yet been made in the developement of
the laws which regulate the formation and decomposition
of organic substances. Whether we shall ever be able to
reach this point is questionable ; it can only be hoped for
as the result of an accumulation of facts, ascertained by
careful and persevering examination of the processes them-
selves.

Hence, it is to be regretted that in place of this, the
ingenuity of our distillers should have been so exclusively
directed to the improvement of their apparatus ; and con-
siderable as we must allow their success in this way to have
been, it is highly probable that had the same expense and
labour, neither of which have been spared, been directed
with different views, the results would have been still more
satisfactory.

The usually received explanation of the nature of the
process of fermentation itself, on the changes which take
place during its progress is rather the result of theoretical
reasoning than actual experiment.

Hence, the very laws which regulate the manufacture of
spirits from being founded on data deduced from these
theories, prove uncertain in their application and inade-
quate to their object, and in consequence to ensure the
protection of the fair trader and revenue in a case where
the duty so much exceeds the cost of production, as in this
article, our legislators to obviate the deficiency, have been
under the necessity of imposing checks and regulations of
the most restrictive kind : obliging the manufacturer to
follow a certain routine, and leaving him but a very limited
extent of power to attempt alteration or improvement.

The operation of these laws, therefore, however necessary
in a revenue point of view, must with justice bear part of
the odium of the little progress that has been made in im-
proving this branch of our national industry.

Not that our revenue Boards have been indifferent on the
subject or unaware of these legal differences, though hitherto
from the want of more correct principles, the numerous
attempts that have been made at improvement, have been
found productive of but little real advantage.

224 . Dr. Andrew Steel [March

The importance of the subject whether considered as re-
gards the interest of the agriculturist, the manufacturer,
or the revenue, appears at once from the facts, that in the
United Kingdom, above twenty-three million gallons of
spirits are annually produced, requiring above one and a third
million quarters of grain, the value of which may be esti-
mated at two and a half million pounds sterling, and yield-
ing a revenue to the Crown of above five millions per
annum, exclusive of the malt duty.

That processes involving such vast interests should have
in this country been so much neglected, is certainly to be
wondered at. By our continental neighbours the subject
has been prosecuted with much assiduity. Their not being
hampered by such restrictive laws, in addition to the facilities
afforded in an investigation of this kind, by the immense
quantity of grape juice fermented, has enabled them in
some points decidedly to get the start of us. Not limited
to a certain class of materials, beetroot, potatoes, even the
potatoe apple and a number of other vegetable productions,
are made to yield a quantity of excellent spirit sufficient to
afford a fair remuneration to the distiller.

Although our present revenue laws do not allow this
promiscuous employment of material, we have no doubt
that if it could be shown to be advantageous, to permit the
employment of others than those now sanctioned, or as
regards these if any alteration could be suggested by which
the processes could be shortened or rendered more produc-
tive, little difficulty would be experienced in obtaining such
a modification of the laws as to give encouragement to the
improvement of a manufacture of such national importance.

At present an inquiry of this kind is one of peculiar interest
from the question of the propriety of the introduction of
molasses as material into our Breweries and Distilleries,
having been so lately the subject of a Parliamentary inves-
tigation, and the very contradictory evidence delivered to
the committee of the House of Commons, is a sufficient
proof, if any were wanting, how uncertain the notions of
even practical men are on this subject.

Having the results of a considerable number of experi-
ments connected with these points which we have made at
different times, a knowledge of which we think will be
found useful both by the manufacturer and chemist, and at

1835.] on Spirits. 225

all events may serve to draw the attention of others more
qualified to the subject ; we have been induced to arrange
them as in the following papers, and shall in the present,
as preliminary, confine ourselves to the composition of
spirits of different specific gravities, a fact necessary to be
accurately ascertained before proceeding to an examination
of the processes by which they are produced.

Various tables of this kind have, indeed, been published in
the continental periodicals, but besides differing from each
other, and being drawn up for temperatures rendering a
calculation, and that from uncertain data, necessary to re-
duce them to that usually employed in this country, the
specific gravities are only given the length of three figures,
a degree of accuracy scarcely sufficient even for practical
purposes.

The very elaborate tables of Mr. Gilpin published in the
transactions of the Royal Society for the year 1794, the
result of four years experimenting, though highly valuable
in themselves, from the inconvenient form in which they
are drawn up, and the unfortunate choice of a compound in
place of pure alcohol as the standard; the calculations
necessary in making use of them in practice are so tedious
and complicated, as to have rendered them of but very little
practical utility.

From the care and attention bestowed on these experi-
ments, the accuracy of the results can hardly be questioned ;
hence, any attempts at repetition, on the same extended
scale at least, and probably with an inferior apparatus,
would to say the least of it be quite superfluous ; a very few
carefully performed experiments being quite sufficient to
afford data for re-calculating the whole of these experiments
if necessary, and arranging them in a really useful form,
though a very small part is all that will be required for our
present purpose.

These experiments have merely consisted in making
mixtures of alcohol and water, and deducing from the
specific gravity of the compound, the composition of Mr.
Gilpin's standard spirit.

Of the ultimate composition of anhydrous alcohol, the
number of distinguished chemists who have made it the

VOL. I. Q

226 Br. Andrew Steel [March

subject of investigation, and with results so closely agreeing

leave no doubt of its being a compound of

1 Atom Olefant gas . . . . 1*75
1 Atom water 1*125

2-875
or at least of Carbon, Hydrogen and Oxygen in these pro-
portions.

For its preparation various processes have been recom-
mended by different writers. Mixing it with substances
having a powerful affinity for water, as the diliquescent
salts, and distilling, or by placing it along with the same
salts, or what is preferable, with quick lime in separate
vessels under an exhausted receiver.

It is not a matter of indifference however, which of these
processes are followed, as the specific gravity of the result-
ing alcohol will be found to differ ; that obtained by ab-
stracting the water by means of quick-lime, will in general
be found heavier than that obtained by distillation from the
deliquescent salts, more especially carbonate of potash.
This has been accounted for by supposing the formation of
a little ether during the process.

The real reason we believe to be the presence of a small
variable quantity of one or more peculiar oils, of which
every specimen of commercial spirit that we have had an
opportunity of examining contains more or less ; the origin
and nature of which we shall endeavour to ascertain more
particularly afterwards.

When carbonate of potash is employed, the greatest part
of this oily matter is separated, while, by the other process, it
is allowed to remain ; hence, the reason of the difference in
specific gravity ; the correctness of this supposition could
only be proved by ascertaining the specific gravity of the
oil itself, the small quantity that we have been able to
procure has rendered this impracticable, not more indeed
than to allow us from its properties to decide that it was
an oil.#

* It has often been remarked that when potash or its carbonate is added to
spirits, and the mixture allowed to stand for sometime, it becomes yellow coloured,
this, in place of being occasioned by the decomposition of the alcohol, we believe
to be only a test of the presence of the above mentioned oil.

1835.] on Sjnrits. 227

We are, therefore, inclined to give the preference to
Lovvitz's process, though even by it the alcohol obtained is
not always uniform in its specific gravity. The variation is
however but trifling.

When dry carbonate of potash is added to spirits till it is
no longer dissolved, but remains dry at the bottom of the
vessel, the specific gravity of the residual alcohol after dis-
tillation, which is necessary to free it from the yellow
matter and a minute quantity of the carbonate of potash
which it holds in solution, is uniform, varying but very
little, in repeated trials we have made from -8179 at 60°.

The mean of two experiments with peroxide of copper,
performed however, with an apparatus too imperfect to give
more than a mere approximation, gave as its composition :
Olefiant gas . . . 54-632 7-
Water .... 45*368 5*813

100-

Approaching very nearly 4 atoms of alcohol and 1 of water.

That this is really the true composition of the spirit ob-
tained in this way, is still more satisfactorily proved from
its specific gravity being almost identical with that of the
mixture of alcohol and water made in those proportions.

The fact we think if correct will prove valuable by ena-
bling chemists to obtain with comparatively little trouble,
a highly rectified alcohol and that of uniform strength,
from a want of attention to which, and employing alcohol
of different strengths in their experiments, our knowledge
of the properties of this important substance is still ex-
tremely limited.

It was the determination of this point that induced us to
make choice of atomic proportions in the experiments, of
which the following table exhibits the results.

The alcohol employed was of the specific gravity of -79460
at 60°, it contained no trace of oil, nor did it with the nicest
re-agents afford the least indication of containing carbonate

If this yellow coloured alcohol be gently distilled to dryness, the colouring
matter remains behind, combined with the potash, from which it may be separated
by the addition of an acid, under the form of a foeted oil. The whole of this is
not, however, abstracted by one process, but by repetition, rejecting the first
portion distilled in each, we at last obtain an alcohol, which suffers no change
whatever on the addition of potash.

Q2

228

Analyses of Books.

[March

of potash, which has been stated by M. Dubue to be always
the case with alcohol prepared by its means.

The mixtures were made by weight, well shaken, and
allowed to stand 24 hours before the specific gravity of the
mixtures was determined.

Atoms of

Weight of

Spec. Grav.
of Mixture.

Mean
Spec. Grav.

Condensation.

Alcohol.

Water.

Alcohol.

Water.

1

0

2-875

•79460

—

—

4

1

11-5

1-125

•81793

•80945

•00617

3

1

8-625

1-125

•82598

•81392

•01206

2

1

5-75

1-125

•83843

•82224

•01619

1

2-875

1.125

•86726

•84334

•02392

2

2-875

2-25

•90420

•87336

•03084

3

2-875

3-375

•92662

•89373

•03289

4

2-875

4-5

•94118

•90847

•03262

5

2-875

5-625

•95090

•91961

•03130

6

2-875

6-75

•95763

•92833

•02930

7

2-875

7-875

•96243

•93555

•02708

8

2-875

9-

•96597

•94111

•02486

9

2-875

10-125

•96871

•94593

•02278

10

2-875

11-25

•97092

•95002

•02090

C To be continued. J

Article VII.

ANALYSES OF BOOKS.

Philosophical Transactions for 1834, Part II.

This portion of the transactions of the Royal Society contains several
important papers, especially in the department of electricity. The
contents are :

On some Elementary Laws of Electricity. By W. Snow Har-
ris, F. R. S.

On a general method in Dynamics. By W. R. Hamilton, Esq.

An Investigation of the Laws which govern the motion of Steam
Vessels, by P. W. Barlow, Esq.

On* the generation of the Marsupial Animals. By R. Owen, Esq.

Observations on the structure and functions of tubular and cellular
Polypi and of Ascidiae. By Joseph J. Lister, Esq.

On the nervous system of the Sphynx Ligustri. By G. New-
port, Esq.

Experimental Researches in Electricity, 8th Series. By M. Fa-
raday.

1835.] Philosophical Transactions for 1.834. 229

On the functions of some parts of the Brain. By Sir Charles Bell

On the repulsive power of Heat. By the Rev. B. Powell.

On the equilibrium of a mass of Homogeneous Fluid at liberty.
By James Ivory, Esq.

Observations on Torpedo. By John Davy, M. D.

Remarks in reply to Dr. Daubeny on the air disengaged from the
recent Volcano. By John Davy, M. D.

On the ova of the Ornithorynchus Paradoxus. By R. Owen, Esq.

Observations on the motions of Shingle Beaches. By H. R. Pal-
mer, Esq.

Analysis of the Moira Brine Spring. By A. Ure, M. D.

Experiments on the Velocity of Electricity, &c. By C. Wheat-
stone, Esq.

Electricity. — Mr. Harris for the purpose of prosecuting his re-
searches invented a new electrometer, by the medium of which he
has observed two new laws. 1 . A given quantity divided upon two
perfectly similar conductors, was found to exert upon external bodies
only a fourth part of the attractive force apparent when disposed upon
one of them. 2. When divided upon three perfectly similar con-
ductors, the force upon either is only one ninth of the force apparent
when disposed upon one of them, and so on ; that is, the quantity
being constant, the force is as the square of the surface inversely, or
the surface being constant as the square of the quantity directly.
These are illustrated by the following experiment :

Three or four perfectly similar and equal conductors of a cylindri-
cal form being well insulated, a given quantity of electricity was
communicated to one of them by means of a charged jar, and the at-
tractive force measured by the electrometer. The electrified bodies
being now reduced to a neutral state, a second equal quantity was
again communicated to the same conductor as before, after which it
was caused to touch one of the others so as to divide the charge on
both. Each conductor was observed to be equally charged ; the force
however after making the requisite correction for distance between
the attracting bodies amounted only to one fourth of the previous
force. The results are represented in the following table :

Comparative quantity.

l . . .
J . . .
i . . .

i • • •

2. The author distinguishes three elements peculiar to the condi-
tions of electrical accumulation. 1. The comparative quantity actu-
ally accumulated. 2. The quantity not sensible to the electrometer.
3. The quantity appreciable by the electrometer.

3. It was supposed by Mr. Singer, that the diminished intensity
observable in disposing a given quantity of electricity, is altogether
referable to the attractive force of the atmosphere,to the influence of
which the electric particles become more extensively exposed ; but
this hypothesis is not corroborated by the experiments of Mr. Harris

Force in degrees.

Distance of attracting

l'orce at distance

surfaces.

of an inch.

30° . .

. . 1 .

.

. 30°

5— . .

. . 1-25 .

.

7-8—

2+ . .

. . 1-28 .

.

3-27 +

1+ . .

. . 1-29 .

1-8-f

230 Analyses of Books. [March

He placed a brass ball about two inches in diameter in the centre of
a large receiver, and connected it with an electroscope by means of
a brass rod passing right through a collar fixed in a glass plate and
socket. A quantity of electricity was communicated to the ball, suf-
ficient to cause a divergence of 40° in the electroscope. This effect
was not influenced by removing fifty-nine sixtieths of the air in the
receiver. •

4. In reference to the transmission of electricity between con-
ductors, it appears that when the attracting force operating between
two conductors can overcome the atmospheric pressure, a discharge
ensues between the nearest points of the opposed surfaces. In these
points the force appears to become at length indefinitely great in re-
spect of points more remote, so that the whole quantity accumulated
is finally determined through them. Thus the precise points of con-
tact between two spheres being found, and the spheres subsequently
separated by given distances measured between these points, it may
be shewn that the respective quantities requisite to produce a dis-
charge will vary with the distances directly. The distance at which
electricity can be discharged in air of a given density is an accurate
measure of the comparative quantity contained in a unit of space, or
of the tension (by which is to be understood the elastic force of a given
quantity accumulated in a given space, and is directly as the density
of the stratum,) and the attractive force discovered by the electrome-
ter, or the intensity is directly as the square of the quantity con-
tained in a unit of space.

5. The effect of an atmosphere varying in density and temperature
in restraining electrical discharges, is as follows :

1 st. The respective quantities requisite to pass a given interval,
varied in a simple ratio of the density of the air. When the density
was one half as great, the discharge occurred with one half the quan-
tity accumulated, that is to say, with one fourth of the attractive
force indicated by the electrometer. 2nd. The distance through
which a given accumulation could discharge was found to be in an
inverse simple ratio of the density of the air, the intensity or free ac-
tion being constant. In air of one half the density, the discharge
occurred at twice the distance, or the resistance of air to the passage
of electricity is as the square of the density directly, and if as the den-
sity of the air be decreased, the distance between the points of action
be increased, the electrical accumulation will still remain complete.

6. Heated air is not as is frequently stated a conductor of electri-
city, and heat does not facilitate electrical transmission through air
in any other way than by diminishing its density. Supposing heat
to be material, it is a non-conductor of electricity, because the incor-
poration of a conducting with a non-conducting substance is found to
impair the insulating power of the latter, as in the case of air charged
with free vapour, whereas in the intimate union of two non-conduc-
tors the insulating power remains perfect.

7. Sir Humphry Davy has well illustrated the effect of heat in
imparing the conducting power of metals, and the same fact has been
observed by Mr. Christie. Dr. Ritchie, however, has lately brought
forward an objection ; for, in transmitting electricity over a forked
iron rod, one of the legs of which he heated to redness, he found

1835.] Philosophical Transactions for 1834.

231

that the electricity passed in preference from the heated side rather
than from the cool side. To make this experiment free from objec-
tion, it would be necessary to insert the heated iron rod in an
exhausted receiver. Dr. Ritchie was aware of this, but conceives
that the effect of a heated wire would be a species of electrical eva-
poration from its surface. His very ingenious paper in the philoso-
phical transactions has certainly not attracted that attention which it
deserves. The objection stated to his experiment by Mr. Harris,
does not appear to affect the results which he obtained.

8. Volta observed that of two plane surfaces of equal area, that
which has the greatest extension has also the greatest capacity for
electricity. Mr. Harris has prosecuted this fact, and ascertained that
the intensity varies in an inverse ratio of the perimeter of plates
which he employed, varying in shape from a circle through a square
up to a long parallelogram. The following illustrates the results : —

DIMENSIONS, — AREA = 75 SQUARE INCHES.

Length.

Breadth.

Perimeter.

Intensity.

12-5

25-

54-5

6
3
1-4

37 inches.
56 „
112 „

9°

6

3

The extent of edge has no influence on the intensity. The inten-
sities of conductors are therefore, it appears, inversely as their peri-
meters, and the intensity varies in an inverse ratio of the area when
the perimeters remain the same, from which, it follows that the
intensity must vary inversely with those quantities jointly, or calling
I, intensity, A, area, P, perimeter, we have

IOAP

But supposing the quantity of electricity to vary, then the intensity
being as the square of the quantitv, the formula is

t *2
^ AP
and the capacity of a conductor being measured by the quantity of
electricity it can receive under a given intensity, there follows *2 a
I A P, or with a constant intensity, * representing the capacity, we

obtain capacity .

- VAP

It appears that the intensity does not vary in an inverse ratio of
the square of the surface according to the general law, except when
the areas are so disposed that the whole perimeter of the various
plates is as the respective surfaces.

9. The operation of electricity on distant bodies, by induction, is
quite independent of atmospheric pressure, and is exactly the same in
vacuo as in air, the attractive force varying as the squares of the
respective distances inversely.

1st. The attractive force exerted between an electrified and a
neutral uninsulated conductor, is not at all influenced by the form
or disposition of tjie unopposed portions.

2d. The force is as the number of attracting points in operation

232 Analyses of Books. [March

directly, and as the squares of the respective distances inversely ;
hence the attractive force between two parallel plane circles being
found, the force between any other two similar planes will be given.

3d. The attractive force between two unequal circular areas is no
greater than that between two similar areas each equal to the lesser.

4th. The attractive force also of a mere ring and a circular area
on each other, is no greater than that between two similar rings.

5lh. The force between a sphere and an opposed spherical segment
of the same curvature, is no greater than that of two similar segments,
each equal to the given segment.

It has been much agitated whether electricity can pass through a
vacuum, but the fact is, that as it is impossible to produce such
absence of matter by artificial means, it seems unnecessary to dwell
upon it.

The experiments of Harris go to prove that electrical divergence
is completely independent of atmospheric attraction, and is therefore
in accordance with the opinion with which he sets out, that electricity
is a subtle material agent, essentially involved in the constitution of
ordinary matter. The experiments, however, upon which such de-
ductions can be founded, it is obvious, must be conducted with the
greatest delicacy, and in such cases, absolute certainty is scarcely to
be looked for.

The paper of Dr. Faraday constitutes the Eighth Series of his
researches in electricity, and consists of corrected and extended views
of the theory contained in his Fifth and Seventh Series. The whole
paper is pregnant with important matter. It has been objected to
Dr. Faraday's papers on electricity that they are difficult to under-
stand, in consequence of the new nomenclature which he has intro-
duced, and perhaps there is reason, in some instances, in similar com-
plaints, for surely, it is said, when plain English words can express
facts or opinions, it is improper to substitute technical expressions,
either in science or literature ; and a language which can muster, in
alphabetical array, seventy-five thousand words, does not stand in
need of unnecessary innovations. Such observations, however, do not
apply in the present instance ; because, the new terms are few, and
obviate much circumlocution. They may, however, be attended to
with propriety by those who are only entering upon discovery. In
medicine, more especially, it is too obvious that technicalities have
served, in many instances, to form cloaks for ignorance and quackery.

In the present series, the author enters upon the investigation of
the important point whether the supply of electricity is due to
metallic contact or chemical action. For the purpose of determining
this point, he took a plate of zinc, about eight inches long and half
an inch wide, which was cleaned and bent in the middle to a right
angle. A plate of platinum, about three inches long and half an
inch wide, was fastened to a platinum wire, and the latter bent to
a right angle. These two pieces of metal were arranged together,
but outside a vessel, and its contents, which consisted of dilute
sulphuric acid, mingled with a little nitric acid. A piece of folded
bibulous paper, moistened in a solution of iodide of potassium, was

1835.] Scientific Intelligence. 233

placed on the zinc, and was pressed upon by the ends of the platinum
wire. When under these circumstances, the plates were dipped into
the acid of the vessel described, there was an immediate effect at the
bibulous paper, the iodide being decomposed, and iodine appearing at
the anode, i. e., against the end of the platinum wire. As long as
the lower ends of the plates remained in the acid, the electric current
continued, and the decomposition of the iodide proceeded. On re-
moving the end of the wire from place to place on the paper, the
effect was evidently very powerful, and on placing a piece of turmeric
paper between the white paper and zinc, both papers being moistened
with the solution of iodide of potassium, alkali was evolved at the
cathode, against the zinc, in proportion to the evolution of iodine at
the anode. Hence, the decomposition was perfectly polar, and
decidedly dependent upon a current of electricity passing from the
zinc through the acid to the platinum in the vessel, and back from
the platinum, through the solution to the zinc at the bibulous paper.
The fact of the decomposition being produced by the electrical cur-
rent, was proved by the circumstance of the decomposition ceasing
when the acid and its vessel were removed from the plates, and being
again removed when the contact was repeated. The same position
was deduced by varying the experiment, amalgamating pieces of
zinc over the whole surface, and employing dilute sulphuric acid in
the vessel. The same effects resulted when caustic potash was used
instead of acid, and also when brine was substituted. The inferences
which the author draws are, 1st., That metallic contact is not neces-
sary for the production of the voltaic current; 2d., That a most
extraordinary mutual relation of chemical affinities of the fluid exists
which excites the current and the fluid which is decomposed by it.

The use of metallic contact in a single pair of plates appears evi-
dent from the experiments. For when an amalgamated zinc plate
is dipped into dilute sulphuric acid, the force of chemical affinity
exerted between the metal and the fluid is not sufficiently powerful
to cause sensible action at the surfaces of contact, and occasion the
decomposition of water by the oxidation of the metal, although it is
sufficient to produce such a condition of the electricity as would
produce a current if there was a path open for it.

Now, the presence of a piece of platinum touching both the zinc
and the fluid to be decomposed opens the path required for the elec-
tricity, because only one set of opposing affinities are to be overcome ;
whereas, when metallic contact is not allowed, two sets of opposing
affinities must be conquered. Some have considered it impossible to
decompose bodies by Hare's calorimeter, or Wollaston's powerful
single pair of plates, but this was owing to their considering the
decomposition of water a test of the passage of an electric current.
But the author observed that bodies would differ in facility of decom-
position by a given electric current, according to the condition and
intensity of their ordinary chemical affinities, and he has corroborated
the fact by new experiments. In employing different fluids to excite
the action, he procured currents of electricity varying in intensity
and by consequence in their effects. Dilute sulphuric acid acting
upon the zinc and platinum plates decomposed iodide of potassium.

234 Analyses of Books. [March

protochloride of tin, chloride of silver, but water acidulated with
sulphuric acid, solution of muriatic acid, solution of sulphate of
soda, fused nitre , and the fused chloride and iodide of lead, were
not affected by a single pair of plates excited only by dilute sulphuric
acid. All these substances were, however, readily decomposed by
adding a little nitric acid to the dilute sulphuric acid. It is suffi-
ciently obvious that the addition of the nitric acid operated by in-
creasing the intensity or power of the current.

By the reference which is thus made of the intensity of the electric
current to the intensity of the chemical action, the conclusion is
drawn that by using bodies such as fused chlorides, salts, &c, which
may act upon the metals with different degrees of force, effects
would be obtained due to different intensities, which would serve to
assist in the construction of a scale, so as to supply the means of
determining relative degrees of intensity accurately in future re-
searches. The bodies which have been examined are decomposed in
the following order, the first being disunited by the current of the
lowest intensity. Iodide of potassium (solution.) Chloride of silver
(fused.) Protochloride of tin (fused.) Chloride of lead (fused.)
Iodide of lead (fused.) Muriatic acid (solution.) Water acidulated
with sulphuric acid.

Another proof that metallic contact has nothing to do with the
production of electricity, and that electricity is only another mode
of the exertion of chemical forces, is the production of the electric
spark before the metals are brought in contact, and by the influence
of pure chemical agency in an experiment where the spark is obtained
by placing in contact a plate of zinc and a plate of copper, and plung-
ing them in dilute sulphuric acid.

The principles which the author endeavours to establish in the
course of his researches are, that the electricity of the voltaic pile is
not dependent either in its origin or its continuance to the contact of
the metals with each other. It is entirely due to chemical action,
and is proportionate in its intensity to the intensity of the affinities
concerned in its production, and in its quantity to the quantity of
matter which has been chemically active during its evolution. The
production of electricity is a case of chemical action, while electric de-
composition is simply a preponderance of one set of chemical affinities
over another set which are less powerful. The scource of the elec-
tricity exists in the chemical action which takes place directly between
the metal and the body with which it combines, and not in the
subsequent action of the substance so produced with the acid present.
Thus if zinc, platinum, and muriatic acid are employed, the elec-
tricity depends upon the affinity of the zinc for the chlorine, and
circulates in proportion to the number of atoms of the zinc and
chlorine which unite. But for this direct action upon the metal
itself, it is essential that the oxygen or other body be in the state of
combination, and limited to the state of an electrolyte, that is a
body which is decomposed when the electric current is transmitted
through it.

Some bodies there are which are capable of exerting chemical
action upon the metals which arc not electrolytic ; but these must

1835.] Philosophical Transactions for 1834. 235

be chosen from among the metals ; charcoal also answers. No elec-
tric current is however induced by these means. An electrolyte is
always a compound body, and can act as an electric conductor only
when decomposing. Water is the most familiar electrolyte. The
attraction of the zinc for the oxygen is greater in the case of water
than that of the oxygen for the hydrogen, but in combining with it,
it tends to throw into circulation a current of electricity in a certain
direction. The sulphuric acid used in the voltaic circuit is not capable
of producing any sensible portion of the electricity of the current,
by its combination with the oxide formed, because it forms no part
of an electrolite, nor is it in relation with any other body present
in the solution which will permit of the mutual transfer of the par-
ticles, and the consequent conduction of the electricity. Now, an
electrolyte conducts in consequence of the mutual action of its
particles, but the elements of the water and sulphuric are destitute
of this relation. This corroborates the statement of Sir H. Davy,
that no electric current is induced by the combination of acids and
alkalies. If the acid and base be dissolved in water, it is possible
that a small portion of electricity, proceeding from chemical action,
may be conducted by the water without decomposition, but the
quantity will bear no proportion to the equivalents of chemical force.
If a hydrogen acid be used, then a current may be induced by the
chemical action of the acid on the base, for both bodies now act as
electrolytes.

This view of the oxidation of the metal being the cause of the elec-
tric current, is proved by the effects of alkaline and sulphuretted solu-
tions when used as conductors. It cannot be supposed that the alkali
acts chemically as an acid to the oxide formed, because our knowledge
leads to the conclusion that the ordinary metallic oxides act rather as
acids to the alkalies. Ammonia as well as potash produced the same
electric currents. Alkalies seem not to be influenced by the acids, in
effecting electrical currents, but are superior in force and in bringing
a metal into what is called the positive state. It is proved by the
fact that if zinc and tin be used, or tin and lead, whatever metal is
put into the alkali becomes positive, that in the acid being negative.
Davy shewed that if iron and copper were plunged into dilute acid,
the current passed from the iron through the fluid to the copper.
In the solution of sulphuret of potash it is reversed. Two experi-
ments in addition complete the series of proofs of the origin of elec-
tricity on the voltaic pile. A fluid amalgam of potassium containing
not more than -~ of that metal was put into pure water, and con_
nected through the galvanometer with a plate of platinum in the same
water ; a current passed from the amalgam to the platinum, which
must have been owing alone to the oxidation. Again, a plate of clean
lead and a plate of platinum were placed in pure water, a current
passed from the lead to the platinum, so intense as to decompose a
solution of the iodide of potassium, when acted upon in the manner
described at the beginning of the paper. This likewise appears to
have been an instance of the effect of oxidation.

An important point to determine is the state of the metals and the
conductor in a simple circuit, before, and at the instant when the
metallic contact is completed. Dr. Faraday conceives it impossible

236 Scientific Intelligence. [March

to resist the idea that the voltaic current which we have seen is de-
pendent upon oxidation, must be preceded by a state of tension in the
fluid, and between the fluid and the zinc, the first consequence of the
affinity of the zinc for the oxygen of the water. He endeavoured to
investigate this by transmitting a ray of polarized light through a
solution of sulphate of soda across the course of the electric current,
and examined it by an analyzing plate, but though it penetrated
seven inches, not the slightest trace of action on the ray could be de-
tected, nor was the effect different when nitrate of lead was substi-
tuted. A beautiful experiment proves a state of tension acquired by
the metals and the electrolyte before the electric current is produced,
and before the metals are brought in contact. He took a voltaic ap-
paratus consisting of a single pair of large plates, namely, a cylinder
of amalgamated zinc and a double cylinder of copper, and placed them
in ajar containing dilute sulphuric acid, so that they could at plea-
sure be placed in metallic communication by means of a copper
wire, arranged so as to deposit the ends into two vessels of mercury
connected with the two plates. As long as the plates were kept sepa-
rate no action occurred ; but when connected, a spark (contrary to
the common idea) was elicited, and the solution decomposed. Hence,
it appears that as the electricity is produced by the material action
of the zinc and water, so these by being brought in contact are placed
in a state of powerful tension, which, although it did not decompose
the water, caused a spark to pass between the zinc and a fit discharger
when the interval was small enough. The idea which Berzelius has
broached that the heat and light of combustion are the consequences
of the action of chemical affinity, without the production of an elec-
tric current, appears to the author to be a mere imagination.

With regard to the direction of the movement of evolved and com-
bining bodies, it appears that if in a voltaic circuit, the activity of
which is determined by the attraction of zinc for the oxygen of water,
the zinc move from right to left, then any other cation included in
the circuit being part of an electrolyte will also move in the same
direction, and as the oxygen of the water by its natural affinity for
the zinc, moves from left to right, so any other body of the same class
with it I. e. any anion will follow the same course.

These statements of our author correspond with the general views
of Davy in his Bakerian lecture.

(To be continued.)

Article VIII.

SCIENTIFIC INTELLIGENCE.

I. — Mellonis Experiments on Heat.

Royal Institution Evening Lecture, 23rd of January.

Dr. Faraday commenced the lectures of the season by describing
and exhibiting the experiments which Melloni, a young Italian
philosopher now resident at Paris, contrived to elucidate the nature
of heat.

The great improvement which he has introduced, and which bids

1835.] Scientific Intelligence. 237

fair to enable us soon to develope completely the cause of the pheno-
mena dependent on the presence of this important principle, is the
adaptation of the thermo-multiplier as a delicate indicator of sensible
heat. All the experiments which had been previously made on this
subject were performed by means of Leslie's differential thermometer,
which although comparatively, as to other instruments a delicate
contrivance, is surpassed in an infinite degree by the thermo-multi-
plier. The multiplier consists of about 30 pairs of bars of bismuth
and antimony ; the elements being so extremely delicately formed
that the extremities present a surface of ~ of an inch square. These
are made to communicate with the multiplier, by means of wires
leading from the extreme bars. The multiplier consists of a coil of
silver wire, armed with silk, and having a magnetic needle so placed
in a free space within the centre of the coil, as to enable it to oscillate
readily. Now, it was observed by Melloni, that when heat, even
that of the hand, is applied to the pile, a powerful effect is produced
upon the needle of the multiplier, which undergoes an immediate
declination, and traverses an arc more or less great if the heat is
constant in a constant interval. It is quite obvious, therefore, that
this must be a most excellent thermoscope, and must be admirably
adapted to the delicacy which is necessary in experimenting in re-
ference to heat. Provided, then, with this apparatus, Melloni set
about examining accurately the relations of heat and light, a problem
which philosophers have long been endeavouring to elucidate. For
this purpose, he studied permeability of heat through different bodies.
Mariotte concluded, from his experiments, that the heat of a common
fire does not pass through glass, or at least, in very minute quantity.
Scheele went further, and decided that not a ray of heat traversed
glass. Pictet, however, repeated Scheele's experiment, and obtained
a contrary result. From these observations, and those of Herschel,
it was inferred that heat does not pass through diaphanous substances,
with the exception of atmospheric air. Prevost and Delaroche, by
ingenious adaptations, proved, however, that heat is transmitted
directly through glass, independent of its conducting power, and this
fact has been allowed, with few exceptions, by all philosophers.
But although this admission was made, the subject was involved in
great obscurity, and presented an inviting field of inquiry to the
ingenuity of Melloni. No examination had been instituted into the
influence of the state of the surface, of the thickness of the substances
through which the heat was transmitted, or of their internal struc-
ture upon permeating heat. These, however, were taken up by
Melloni, and he is still engaged in the prosecution of his researches.
It is easy to see how the different relative diathermal powers or
capacities of bodies for transmitting heat could be determined by the
apparatus of Melloni, for all that was required was to interpose the
substance whose powers were to be investigated, between a steady
heat and the voltaic pile, when their capacities would be indicated by
the rapidity of the action upon the needle. That the heat is actually
transmitted, and does not pass by conduction, is proved by the fact
that the internal portions of the glass do not instantly become heated,
which is demonstrated by placing a glass screen in front of the pile,
nd intercepting the communication with the source of heat. The

238 Scientific Intelligence. [March

posterior surface of the glass plate would radiate the heat conducted
from its interior towards the pile if the hypothesis that the heat is
communicated by conduction were correct. But this does not occur,
and hence, there is no alternative left but the conclusion that heat
permeates bodies directly. Heat and light agree, therefore, in this
property, that both possess the power of passing through bodies. It
is proper that each should have such a capacity distinguished by
appropriate names, until their identity be proved. Melloni terms
the permeating power of heat through bodies, diathermal power,
just as we indicate capacity of bodies to transmit light by the names,
transparency, opalesence, &c. The diathermal power is subject to
similar modifications. Heat, however, differs from light in this
respect, that the facility with which it is transmitted by different
bodies has no relation to their transparency.

Thus if we suppose the rays of a constant heat to be represented by
100, the only body which appears but slightly to diminish this when
interposed as a screen is rock salt, whose diathermal capacity is 92,
but the quantity of heat transmitted through a crystal of smoke-co-
loured quartz will be denoted by 57, and through a crystal of alum
by 12 where the difference is so very great as to excite astonishment.
This and similar facts have induced Melloni to conclude that heat
and light are distinct ; but in this opinion Dr. Faraday does not
coincide.

Melloni has also examined the diathermal relation of colours, and
has found that their powers are in the following order : violet 53,
yellowish red 53, purple red 51, bright red 47, pale violet 45, orange
red 44, clear blue 42, deep yellow 40, bright yellow 34, golden yel-
low 33, dark blue 33, apple green 26, mineral green 23, very deep
blue 1 9. Hence, we see that the mineral relations of the colours to
their heating power is so completely altered that the violet ray which
in the spectrum possesses temperature 25 or 30 times below that of the
red ray, observes here a higher temperature, but the result seems mo-
dified as occurs with light by the nature of the power employed, to
illustrate the comparative experiments.

Dr. Faraday exhibited many of the experiments which Melloni
has described in his papers, especially in reference to the diathermal
properties of rock salt, glass, alum, with screens of which substances
he had been supplied. The absorptive power of different colours, in
relation to the solar spectrum was well illustrated by means of the oxy-
hydrogen blowpipe. The contrivance of passing the decomposed ray
through a volume of disengaged ammonia had a happy effect, the co-
lours of the spectrum being as it were made to float in the air.

He likewise exhibited the method of polarizing light by means
of tourmaline, by which fanciful figures are formed, and light
transmitted or withheld by merely altering the relative position
of the screens properly adapted.

Dr. Faraday directed the attention of the meeting to a fine bust
of Mr. Fuller by Chantry, and observed that the title engraved on it
was a sufficient eulogium : " John Fuller, who gave ,£10,000 for the
encouragement of Science in the Royal Institution." A fine painting
of Earl Spencer was exposed for the first time in the library, where
also several ingenious models and casts, and several specimens of litho-
graphic printing from zinc plates attracted notice.

1835.] Scientific Intelligence. 239

1 1 . — Microscopal Objects .
Mr. Andrew Pritchard, Pickett Street, Strand, has just published
a useful little work for such persons as take an interest in examining
the beauties of the minute works of nature. It contains a list of 2000
microscopic objects, and is intended to serve as a guide for selecting
and labelling subjects of natural history, botany and mineralogy. Some
good observations are prefixed in reference to mounting microscopical
subjects, with remarks on the circulation of animals and plants.
III. — Isinglass.
From the experiments made by Mr. Smith in the United States, it
appears that the intestines of the fish the gadus merluccius furnish
the purest species of isinglass, (Journ. de Pharm. xx. 593.) not
inferior to that obtained from the sturgeon. The swimming bladder
of this fish is larger than that of other species of the same family.
It is cut out and washed with pure water, and then dried in the
sun. When partially dry it is pressed between wooden rollers as
thin as paper. The long stripes of isinglass which are met with in
commerce, are the intestines of the gadus morrhua.

IV. — Prize of the Imperial Academy of Sciences of
St. Petersburg, for 1836.
For a considerable period it has been known that in some insects,
besides the abdominal nervous system, there exists another very deli-
cate series of nerves, situated on the dorsal portion of these animals.
Something analogous has been noticed in the class of annelides, as
in the leech, &c. This system deserves attention, because it seems
to bear some resemblance to the sympathetic nerve in vertebrated
animals. The Academy proposes for the subject of the prize for the
ensuing year, " Researches upon the different degrees of develope-
ment of the intestinal nerves in invertebrated animals, accompanied
with exact and detailed designs." They request attention to the
following points : —

1. What is the developement of the intestinal nervous system in
those classes of invertebrate animals where it has been observed ?
(especially tenthredinates, ichneumones, and some sections of hemi-
pipterous and dipterous insects. )

2. Can a system of intestinal nerves be demonstrated in any inver-
tebrated animals besides those in which they have been already found?

3. Can the different forms of the system of intestinal nerves be
reduced to certain general types ?

4. Do these general types agree with established classifications, or
do the intestinal nerves follow a peculiar developement ?

5. What relations subsist between the intestinal system, of nerves
and the rest of the nervous system, in reference to ramification and
size ?

6. What reasons can be alleged for or against the analogy which
exists between this nervous system and the sympathetic nerve in
superior animals ?

The academy will grant a prize of 200 ducats to the person who
shall resolve this question ; but in case none of the essays sent are
completely satisfactory, the author of the best of these will receive
according to the extent and importance of his work, an encouraging
prize of 100 or 50 ducats.

The memoirs cannot be received after the 1st of August 1836.

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RECORDS

OF

GENERAL SCIENCE

APRIL, 1835.

Article I,

Biographical Account of M. Desfontaines. By Aug-Pyr De
Candolle. {Abridged from the Ann. des Scien. Naturelles,
March 1834.)

Rene Louiche Desfontaines was born at Tremblay, in
the department Ille-et-Vilaine, in Brittany, a town dis-
tinguished as being the birth-place of the anatomist Bertin.
His birth-day it is impossible to ascertain, as the registers
of Tremblay were destroyed during the revolution. He
was himself of opinion, that he first saw the light towards
the end of 1751, or beginning of 1752. His father, though
poor, exerted himself for the purpose of giving him as good
an education as possible, and sent him to school in his native
town, where he learned a little Latin. The master also
endeavoured to form his morals, but treated him in the
harshest manner, reprimanding and punishing him for
the slightest faults, and grating his ears with the dis-
couraging cry that he was good for nothing. One day he
was threatened with severe punishment for having taken
some apples from a garden, and in order to escape from his
master, made his escape by a window and fled to his father's
house. What was the embarrassment then of his family?
What shall we do, they exclaimed, with this refractory boy
w ho resists all chastisement and is fit for nothing 1 His
father, persuaded by the opinion of the master, and believ-
ing that his son was not capable of making any progress in

VOL.1. R

242 Biographical Account of [April

his studies, determined to make him a cabin boy. What
the causes were which prevented him from following up
this project are unknown, but it is probable that Science is
indebted to his maternal interposition for one of her most
distinguished supporters. It was determined, however,
that another opportunity should be afforded him of acquir-
ing knowledge, and the little apple stealer was sent to the
College of Rennes.

The young scholar was at first impressed with the idea
which had been so often repeated to him by his first master,
of his being destitute of intellectual capacity, that he could
scarce persuade himself of the contrary. He distinguished
himself, however, in some of his first tasks ; received praise
for his success ; had new zeal instilled into his mind, and
at the end of the year carried off several prizes.

In communicating the good news to his father, he
requested him to inform his first master of his success,
and to remind him of his prediction that he had no capacity
for any thing. He continued this innocent spirit of revenge
at each new victory, and it is remarkable, that he did not
cease to send similar communications until he was elected
a Member of the Academy of Sciences. Those who were
acquainted with Desfontaines could scarcely recognize in
this anecdote of his youth, that continual modesty which so
highly characterized him.

In consequence of his success at the College of Rennes,
Desfontaines was sent to Paris to prosecute the study of
medicine. He soon attached himself, in preference, to
botany, and it was in consequence of his devotion to this
study that the period of his graduation was retarded till
1782, in his 30th year. In the course of his medical studies
he became intimate with Lemonnier, first physician to the
king, and professor of botany to the Jardin des Plantes.
Lemonnier, although not holding a place among the first
ranks in Science, greatly contributed to its progress in
France, by the influence which his situation enabled him to
exercise with the powerful persons in the state, and the
employment which he gave to promising naturalists.
Commerson, Michaux, Labillardiere, and Desfontaines,
were indebted for a portion of their success to his patronage.
Alas ! at the same time, the two last have terminated their

1835.] M. Desfontaines. 243

mortal career, and history alone remains to bear witness
of their labours. #

Desfontaines became the favourite and intimate friend of
Lemonnier. Their simple and excellent characters, their
devotion to science and the investigation of truth, established
between them a powerful friendship, notwithstanding the
difference of their ages. It was a similar mildness and
amiableness of character which united in the bonds of
friendship Desfontaines with Malesherbes, Duhamel,
Denainvilliers, Fougeroux, and others. Desfontaines was
also encouraged by M. Antoine Laurent de Jussieu, who
was some years older than himself, and who had succeeded
his uncle Bernard in the professorship of the Jardin du Roi.
In 1783 he was made a Member of the Academy of Sciences.
This title, which is so justly honourable, was deserved by
his Memoirs on Tithonia and Ailantus, and upon the Irrita-
bility of the Sexual Organs. Determined not to remain
idle, he procured the necessary funds for accomplishing a
botanical journey, and encouraged by his countryman
M. De Kercy, consul at Algiers, he determined to investi-
gate the coast of Barbary, from the frontiers of Tripoli to
those of Morocco, viz : the territories of Algiers and Tunis.
These countries, although so near Europe, had been little
visited, and had not been examined in a botanical point of
view, except cursorily, by Dr. Shaw. Desfontaines' plan
was approved of by the Academy, and on the 16th August
1783, he departed from Marseilles for Tunis.

He remained two years in these countries ; visited them
in their whole extent, from the sea to the summits of
Mount Atlas, and even examined the narrow strip of land
which lies to the south of this ridge, and between it and
the desert of Sahara. His examination of these govern-
ments was facilitated by the protection of the French consul,
and by the kindness with which he inspired the Deys. He
had permission to visit the whole country, under the care
of an armed Turk. Although he felt the advantage of this

* Jacq Jul Hauton de Labillardiere, was born at Alencon, in 1755, and died
at Paris, 8th January 1834, fifty-three days after his intimate friend Desfontaines.
He travelled in Syria under the patronge of Lemonnier, and accompanied Entrecas-
teaux in his search for La Perouse. He had published five portions of his work
on the Plants of Syria ; a Voyage round the World ; two volumes on the Plants
of New Holland, and New Caledonia, besides some Memoirs.

2r

244 Biographical Account of [April

protection, he was in constant uneasiness lest the slightest
insult offered by a Moor should be resented by his guard,
whose brutality inspired him with horror. Very different
was the character of the ignorant and barbarous princes of
these kingdoms, who administered justice to their subjects
in an equitable though rude manner.

During the two years of his residence in Barbary, Des-
fontaines laboured without ceasing. Strong and vigorous
in his constitution, sober in his habits, active in investigat-
ing every subject which came under his notice, he studied
ardently the botany of this country, and although half a
century has elapsed since he left it, scarce a single plant
has been discovered which had escaped his searching eye.

He turned his attention also to the study of animals.
His fine collection of insects, deposited in the Museum of
Natural History, furnished Fabricius and Latreille with
several new species; and in 1787, he published a memoir
describing several new species of birds which he found on
the coast of Barbary. He studied also antiquities, and
wrote several papers on ancient geography and ancient
monuments. His Memoirs on the Lotos of Lybia, which
supported the Lotophagi ; that upon the acorns of Atlas,
and one on the economical uses of dates, are proofs of his
classical knowledge, and of the critical acumen with which
he exercised it.

During his residence in Barbary, he formed a friendship
with two botanists who visited that country with similar
views to his own, which death alone terminated. These
were M. M. Martin Vahl, professor of botany at Copenhagen,
who has acquired great celebrity as an accurate botanist,
and M. Poiret, who has published on Barbary, and reserved
the account of some of his labours for the Encyclopedic Me-
thodique. Connexions thus formed amid toil and danger,
are much more indelible than friendships contracted amid
the haunts of civilization. De Candolle makes this remark,
from having often heard these old men relate with energy
and pleasure the recollections of this active period of
their lives.

On his return to Paris in 1785, Desfontaines found
Lemonnier as friendly as ever, who at this time had almost
engaged him in the unfortunate expedition of La Perouse ;
when illness prevented the intended project from being

1835.] M. Desfontaines. 245

carried into effect. His protector then used his influence
to have him appointed his successor, with the intention
himself of resigning the situation which he held of Professor
of Botany in the Jardin du Roi. This establishment was
then under the direction of Buffon, who joined to his su-
perior talents an overbearing manner, as is well known. He
possessed ex officio the patronage of the professorships, and
M. Lemonnier was afraid if he resigned, that a stranger
would be appointed in his place. He represented the matter
to Buffon, but although they were on intimate terms, no
answer could be obtained except, " Let M. Lemonnier give
in his resignation and I shall exercise the powers of my office.3'

After hesitating for a considerable time, Lemonnier, how-
ever, thought he could understand the intention of Buffon,
and resigned his situation without receiving any assurance
from Buffon. For two days no answer was received from
Buffon ; but at the expiration of that time he nominated
Desfontaines, giving him to understand that he did so, not
for the sake of his patron but from his own free will. Thus,
in 1786, Desfontaines found himself in a situation exactly
suited to his taste. From this period he continued to receive
new honours from the learned and from government ; being
one of the first named for the formation of the institute ;
elected by his associates to the chair of the Academy of
Sciences, and Administrator to the Museum. He was ap-
pointed a Knight of the Legion of Honour, and nominated
professor of Botany to the Faculty of Sciences of Paris.

The cares and duties in which he was thus engaged pre-
vented him from drawing up the result of his labours in
Barbary. Louis XVI, who had taken a great interest in
this expedition from the account which his physician had
given him, expressed a desire to peruse his manuscripts,
and Lemonnier requested his friend to entrust his journals
to him, in order that the king might read them.

These journals were unfortunately mis-laid, and as he
possessed no regular copy of them, all this portion of his
travels which did not consist of collections was completely
lost. A few fragments retained by him, containing an im-
perfect account of the first part of his travels, were pub-
lished by Lalande in 1784, in the Journal des Savans. This
accident discouraged Desfontaines, and it was not till near

246 Biographical Account of [April

the close of his career, and when the expedition to Algiers
attracted attention to that country, that he yielded to the
request of Walkenaer to admit of the publication of his
manuscripts.

These fragments appeared in 1830, in the Nouvelles An-
nates des Voyages (vol. xvi, xvii.) but their author took no
part in the publication, and often regretted that a publication
of his should have been presented to the public, written in
such a careless style and so disfigured with typographical
errors.

Desfontaines being thus prevented from writing a his-
torical account of his travels, devoted his time entirely to
botany ; bestowing much pains on the nomenclature of the
plants of the garden and on his botanical course. In the
latter, he developed the principles of vegetable physiology.

His manner was simple and clear, without any pretension,
and till the last his. lectures were flocked to. Extracts from
these have been published in the first volume of the Decade
Philosophique, and re-printed in the Annates oV Usteri. At
this period of his life, being occupied with the study of the
plants of Barbary, he -presented to the Academy several
descriptive memoirs which were published either in his
Memoirs, in the Journal of Fourcroy, or in the Actes de la
Societe oV histoire Naturelle.

During the bloody period of the revolution, Desfontaines
remained shut up in the Jardin des plantes, engaged with
the description of his herbarium, visiting such men of science
as were cruelly put in prison, and encouraging those who
required it. At his eminent peril he visited M. Ramond
while in confinement. M. Lheritier being basely imprisoned
and threatened with death, Desfontaines with his friend
Thonin exerted himself to procure his pardon. They ob-
tained a suspension of the sentence under the pretext that
Lheritier was about to publish the collections of M. Dom-
bey, and thus saved his life. Such conduct at that eventful
period, must be characterized as a proof of the strongest
friendship and of great courage, and is the more praise-
worthy when the natural timidity of Desfontaines is taken
into consideration ; a timidity, however, which arose from
an excess of modesty and distrust in himself.

On the accession of the calm which succeeded the storms

1835.] M. Desfontaines. 247

of the revolution, Desfontaines appeared at the opening of
the Institute with a work of the first description. His
residence in Barbary had given him an opportunity of seeing
much of the date tree, and his attention had thus been
called to the study of the palm tribe. He had written on
this subject some notes to M. Daubenton, who had made
use of them in his memoir upon the organization of wood,
and had presented a paper upon the subject to the Academy
in 1790.

New reflections, and the comparison of a number of trees
had extended his ideas, and enabled him to comprehend
the intimate relation which exists between the structure
of the trunk and that of the organs of the seed, upon
which the basis of the natural classification was placed.
In 1796, he presented a memoir upon the organization of
monocotyledonous plants, which was received with the
greatest praise by botanists, and placed Desfontaines in
the highest rank of science. This memoir showed the
great differences which exist in the structure and the mode
of increase of the two great classes of Phanerogamous
vegetables of which, one has the conical trunk increasing
by the addition of new layers on the exterior of the ligneous
matter, and the other the cylindrical trunk deprived of
true bark, and increasing by fibres, of which the youngest
are on the centre and the oldest on the sides. This me-
moir confirmed their division by characters of the first
order, opened a new field to anatomists and classifiers, and
although a period of forty years has elapsed, still continues
to be the basis of the principal botanical works, the key
of the natural method of vegetable organography. The
author, astonished at his own triumph, appears to have
considered- that he had produced too great a revolution in
the science, and left to others the developement of the con-
sequences of his discovery, a fact which proves that with
superior talents there must be united a certain firmness of
character, in order to produce the proper consequences from
a discovery.

From the period of his return from Barbary, Desfontaines
was constantly employed in studying, describing, and
drawing the plants which he had collected ; and in 1798, he
began to publish the result of his labours, under the name
of Flore Atlantique. This work created a new era in botany,

248 Biographical Account of [Apri

and has continued to be ranked among the most talented
and classical works. It was when he was finishing this
work that De Candolle became acquainted with him. Des-
fontaines permitted him to work with him, furnished him
with the means for extending his knowledge, guided him
by his advice in the method of observing the characters of
plants, and treated him with the tender feelings of a father.
Most of those who have obtained a scientific name in France,
during the present century, can boast of a similar intimacy.

M. M. De Mirbel, and Adr. de Jussieu have expressed
their gratitude in their eulogium upon him. When he had
completed this great work he directed his strenuous atten-
tion to the garden, in reference to its management, and the
nomenclature of the plants, and even in his old age he was
to be seen carrying books, and his herbarium, for the pur-
pose of correcting errors which had been committed during
the sowing and transplanting of the plants. Neither the
heat of the sun nor the inclemency of the season repressed
his zeal in the discharge of his duty. He published three
editions of a catalogue in 1804, 1815, and 1829.

The establishment of the Annates des Museum, afforded
him an opportunity of describing the new plants which
flowered in the garden. From 1802 to 1807 he wrote those
notices in this work which have contributed so much to
Science, and in 1807 and 1808, he published the beautiful
plates of Aubriet, who had accompanied Tournefort, repre-
senting the plants of the east. This work testified the
great esteem which Desfontaines entertained for the memory
of Tournefort, and served to remove a number of miscon-
ceptions which botanists had fallen into with regard to the
discoveries of this traveller.

During two or three years, in conjunction with De Can-
dolle, he published a portion of a work containing abridged
descriptions of plants cultivated in the Jardin des Plantes,
but the labour was so great that the intention of completing
it was given up. In 1809, he published his Histoire des
Arbres et Arbrisseaux, containing an account of those trees
and shrubs which may be cultivated in France. Its tendency
was practical, and he was assisted in it by M. Deleuze.
After the completion of these works Desfontaines began to
feel a degree of ennui, for he had never possessed any taste
for the world. During the revolution he was in the habit

1835.] M. Desfontaines. 249

of repairing every evening to the Society of his friend
M. Thonin, with whom he spent many agreeable hours, in
company with the painter Van Spaendonck, and the geolo-
gist Faugas de St. Fond. His sister also occasionally visited
him, when she was able to leave her native Brittany. In
these circumstances, having met with a young woman,
without fortune it is true, but of an open and agreeable
character, he married her at the age of 63 years. This
union commenced under happy auspices, and his letters at
that period prove the degree of his happiness. He became
the father of a daughter, for whom he entertained the
greatest affection, which was the more felt in consequence
of his being obliged to separate from his wife, by reason of
a disease induced by a weak and delicate constitution. He
now occupied his time with the examination of the herbaria
of the museum, and from 1815 to 1822, enriched Science
with a description of seventeen new genera of plants, in the
Memoirs of the Museum. These genera are Pogostemon,
Chardinia, Ricinocarpos, Gymnarhena, Ancylanthos, Hetero-
dendron, Mezoneuron, Heterostemon, Ledocarpon, Micrantha,
Dipophractum, Stylobasium, Chamaelancium, Polyphagmos,
Asteranthos, Gyrostemon, Cordylocarpon. He published also
about the same time new observations upon some known
genera, as Leucas, Amaiona. He continued his zeal in making
the reports with which he was entrusted by the Academy
of Sciences, till between his 70th and 80th year, at an age
when most men are anxious for retirement. But his senses
gradually began to fail him ; his sight especially, which was
at one time so acute, became weaker, and in his 80th year
he was threatened with total blindness. Yet, on the 10th
October 1831, while in this state, he wrote a letter to De
Candolle, describing an observation which he had made on
the fecundation of plants, which, although not new, is not
without interest.

It was represented to him that a chance existed of re-
covering his sight by an operation for cataract. Sometimes
he felt inclined to believe this, but at other times he remem-
bered what had been said to his colleague M. Lamarck, on a
similar situation, and he derided his own credulity. Still
he preserved the cheerfulness of his disposition and the
benevolence of his heart ; amused himself with his plants,
and was delighted when he could recognize any of them by

250 Professor Powell on the Repulsion produced [April

the touch. He also drew up notes for the colonization of
Algiers, a point upon which he had been consulted by
government.

One thought alone distressed him in the prospect of
death, the circumstance of leaving his young daughter
without a protector. Fortunately his nephew, to whom
he had acted as a father, and who is a distinguished road
and bridge engineer, had imbibed a tender regard for his
cousin ; and Desfontaines had the pleasure of uniting on
his death-bed, the two individuals whom he most loved.
Government provided for his wife. Thus assured of the
happiness of his dearest friends, he met death amid suffer-
ing it is true, but with a serenity and calmness which
could not be surpassed. The benevolence of his character,
seemed on this occasion, to increase, and " I have learned,"
says Jussieu, " from his death-bed scene to love him still
more." He recited classical recollections, adapted to his
situation, testified his love for those friends who were
present by tender remarks, sent kind remembrances to
those who were absent, and at last, expired on the 16th of
November, 1833, aged 81 years. His situation has been
supplied by M. Adolphe Brongniart, a young botanist of
the highest promise. His herbarium of Barbary, he gave
to the Museum, and his general one has been obtained by
Webb, a botanist, who will undoubtedly make a good use
of it.

M. DeCandolle, gives a list of Desfontaines publications.
They amount to about 70, including memoirs and volumes.
M. De Candolle characterizes Desfontaines as being one of
the most excellent men that could be met with, as well as
one of the most distinguished philosophers of his age.

Article II.

An Abstract of some researches on the Repulsion produced
between Bodies by the action of Heat, with additional
observations. By the Reverend Baden Powell, M.A.,
F.R.S., Savilian Professor of Geometry, Oxford.

The curious point to which my attention has been directed,
is one of those which too generally fail in securing the
attention of philosophers, from the circumstance that they

1835.] between Bodies by the Action of Heat . 251

belong to a class of phenomena hardly coming within the
specific range of any one of the great divisions of Science ;
or rather, belonging equally to several, are but little con-
sidered in any. In the " Records of General Science,"
however, some account of them may perhaps find a place.

At the meeting of the British Association at Edinburgh,
I gave a short statement of the experiments which I had
made : an account of them was also read before the Royal
Society, and is now printed in the Philosophical Transactions
for 1834. But a brief outline of their nature and object
may not be unacceptable to some readers, especially as it
will be essential to render intelligible the further observa-
tions I wish to add.

The expansion of bodies by heat seems to imply a mutual
repulsion of their particles ; and it is a question naturally
suggested, whether such a power of repulsion may not
generally belong to heat, or be excited by it between
particles or masses of matter at sensible as well as insensible
distances. But, however obvious the suggestion of such
an inquiry, it is of a nature not easy to be pursued or
decided.

The subject has been partially investigated by Sig. Libri,
and by M . M . Fresnel and Saigey ; but their researches do
not appear to have been regarded as decisive, and have
ever been viewed with considerable doubt ; and they are
eertainly dependant upon experiments of the most extremely
delicate and difficult kind, and those of Fresnel confessedly
left in an incomplete state.

Recently, the inquiry has been revived by Professor
Forbes of Edinburgh, who has referred to the same
principle to account for the singular phenomena of certain
vibrations of heated metallic bars, first noticed by Mr.
Trevelyan, and since fully investigated by himself in a
paper in the Edinb. Trans, vol. xii.

In a different form the subject had occupied my attention
before I was acquainted with Professor Forbes's investiga-
tions ; but, on reading his paper, a new interest attached to
the inquiry, and in pursuing it, I conceive I have obtained
some results which appear decisive on a question at once
of importance in the analogies of physical action, and which
has hitherto been regarded as at least involved inconsiderable
uncertainty.

The method I pursued was that of forming Newton's rings

252 Professor Powell on the Repulsion produced [April

between lenses, and applying heat, which would afford a
simple mode of deciding the question, if there be any
separation of the glasses by repulsion, since it would be
rendered visible by the contraction of the rings. As to the
error which might arise from the warping of the upper
glass by the heat, it will be evident, on a little considera-
tion, that heat applied outside of either glass will tend, by
the change of figure, in every case, in the first instance, to
diminish the angle of contact : that is, if no other cause
interfere, to make the rings enlarge without altering the
central tint, until the curvature become equal to that of the
convex surface.

I invariably found, however, that from the first moment
the rings regularly contract, and the central tint descends in
the scale till the whole vanishes. There are, however, several
precautions necessary to be attended to. If the glasses be
more than very slightly convex, the portion of surface
throughout, which they approach sufficiently near for the
repulsion to act, is very small. This may render the total
effect far too weak to overcome the weight of the upper
glass, or even its inertia, though placed vertically. With
surfaces of such curvature as to give the first bright ring a
diameter of about 0*3 inch, on placing a red hot poker a
little above the glasses the effect never failed to be produced.
Upon the whole, the experiments, though simple in principle,
certainly require some care ; but with all precautions, and
after the most careful consideration of all causes which can
have tended to produce or affect the result, it appears to
me that the separation of the glasses through the extremely
small, but finite and known spaces, whose changes are
indicated by the degradation of the tints, can only be due
to the real action of a repulsive power, produced or excited
between the surfaces of the glasses by the action of heat.

There are many questions relating to the nature and
properties of this repulsive power, which are immediately
suggested, and some of which appear capable of solution by
variations of the same method.

The distance at which the repulsive power can act is
shown, by these experiments, to extend beyond that at
which the most extreme visible order of Newton's tints is
formed. But I have also repeated the experiment success-
fully with the colours formed under the base of a prism
placed upon a lens of very small convexity ; and according

1835.] between Bodies by the Action of Heat. 253

to the analysis of these colours given by Sir J. Herschel, (on
Light, 641,) the distance is here about the 1100th of an inch.

Beyond these very small distances other methods must
be resorted to. But the certainty of the result within these
limits perhaps confirms its probability at greater distances,
as inferred by Fresnel and Saigey.

I tried several experiments on the effects of different
sorts of surfaces, from which I conceive, though we may
infer that cceteris paribus, the better radiating power of the
surface increases the effect ; yet there are other circum-
stances which affect the result more powerfully, and these
seem to be, in general, whatever may tend to the more rapid
communication of heat.

This is still more conspicuous when the rings are formed
in a thin plate of water between the lenses. The effect is
here even greater than in air, and we may presume, inde-
pendent of radiation.

There are several subordinate circumstances attending
these results which are deserving of notice. When the
lenses are in close contact, there is, in all cases, a consi-
derable attraction opposed to the repulsive power. If the
central black be formed, it requires a very considerable
intensity of heat to overcome the attraction, which at that
minute distance is extremely powerful.

When the heat is removed the colours return, and the rings
are gradually restored to the same character as they had at
first. This is more remarkable when simple plates of glass are
employed as before described. When the heat has restored
the bent glass to a plane figure, on its removal the rings
return, and consequently, the glass is again bent without
any fresh pressure, though the force originally applied to
produce the curvature was very considerable ; this is pro-
bably owing, in a great measure, to atmospheric pressure.
In this case, however, the colours will only return up to a
certain point, generally not higher than the beginning of
the first order.

When two glasses are pressed together there is a repulsion
to be overcome, evinced by the force which it is necessary
to apply, and in general, it is evident, that if a plate resting
on another be bent by pressure, as in these experiments, the
influence of heat in restoring it to a plane form will be
opposed both by the attraction at the centre, which tends
to prevent that part from being raised, and by the repulsion

254 Professor Powell on the Repulsion prQduced [April

towards the exterior parts, which tends to prevent them
from being depressed. When the curvature begins to change,
therefore, there is somewhere between them a neutral or
nodal point whose position does not change ; this point may
be very near, or even in the centre, when the attraction is
very strong there. A remarkable instance of this occurs
when the first black of the scale is formed between glass
plates, and heat carefully applied exactly over the central
point of the black space ; in this case, when the black space
is a | inch or more in diameter, I have often continued the
application of the strongest heat for a great length of time
before any separation could be effected, when at length it
has taken place with a sudden force and an audible click.
Sometimes the black spot has continued unaltered until the
glasses have cracked, when the fragments have still con-
tinued to adhere powerfully : meanwhile the outer rings
have continued gradually enlarging.

In the foregoing statement, I have observed, that in
using plane glasses, it was necessary to allow for the effect
of warping. But there are certain considerations which
show that that precaution is unnecessary. For, acccording
to the beautiful experiments of Sir D. Brewster on the
progress of heat through glass, as evinced by its action on
polarized light, it appears distinctly, that the change of
structure (if I may so speak) in the molecules of the glass is
produced at the same instant, on both sides of the plate : so
that the effect of warping cannot take place. This is ren-
dered evident to the eye, by the symmetrical arrangement
of the luminous bands, from the first moment of the appli-
cation of heat, on each side of the dark central band, which
occupies the neutral line along the middle of the thickness
of the glass.

When two plates of glass are laid upon one another there
is a certain resistance or repulsion which may be overcome
by pressure. We can press them together till attraction
takes place. On removing the pressure they remain adher-
ing. If we press them more they are brought closer, and
produce the colours of thin plates. We may thus produce
successively any given tint, and on removing the pressure
that tint will remain, or the glasses continue in the same
position to which they have been brought.

This seems to show that the attraction and repulsion are
in exact equilibrio at all distances, (within this range,) and

1835.] between Bodies by the Action of Heat. 255

this may hold good with any law, provided the law be the
same for attraction as for repulsion.

On the application of heat a greater intensity of repulsion
is excited ; if we could ascertain the law of its increase with
the distance and increase of temperature, we might thence
infer the law both of attraction and repulsion between the
surfaces ; and thence, (if the expression be integrable,) that
between the molecules of the substances.

All this, as just observed, takes place only within a certain
range of interval. When the central black is formed, we
seem to have arrived at a limit where attraction prevails ;
and where the application, even of great heat, will not
easily overcome it.

The close contact of a glass and liquid in capillary attrac-
tion appears to be within this limit ; for here, in several
cases referred to in my paper, it appears that no application
of heat can overcome the attraction.

With respect to one of those experiments, viz : that of
Sig. Libri, which I had stated I could not succeed in repeat-
ing, I have since been informed that the experiment will
succeed, provided the heat applied to the wire be that of a
flame urged by a blowpipe. This, at any rate, proves the
great intensity of the attraction, which requires so extremely
high a degree of heat to overcome it.

Oxford, Feb. 17, 1835.

Article III.

On Spirits. By Andrew Steel, M. D.
( Continued from p. 228.J

The greatest condensation takes place in the mixture of
1 atom of alcohol, and three of water : experiments made
with a view of determining this point with more minute-
ness, seem rather to indicate it as slightly above this.

Atoms of

Weight of

Spec. Grav.
of Mixture.

Mean
Spec. Grav.

Condensation.

Alcohol.

Water.

Alcohol.

Water.

1
1

1
1

2-9
3*
3-1
325

2-875
2-875
2-875
2-875

3-242
3-375
3-513
3-659

•92446
•92663

•92877
•93095

•81974
•89373
•89581
•89815

•03272
•03290
•03296
•03280

or between 3 atoms and 3* 1

256 Dr. Andrew Steel [April

It is very difficult to make experiments of this nature
with absolute accuracy : allowing a very small error to have
been committed, it would bring it exactly to 3; to which,
however, the experiments approach so nearly, as we think
to warrant the conclusion, that the atomic proportion is
really the point at which the greatest condensation takes
place. So that, we have, at least, two definite compounds
of alcohol and water, possessing distinct properties.

The first is a compound of

4 atoms alcohol . .. . 11*5
1 „ water .... 1-125

12-625

the second of

\ atom alcohol . .

. . 2-875

3 ,, water . .

. . 3-375

6-250 *
From the above, with the assistance of Mr. Gilpin's
table, we have computed the following, exhibiting the

* The condensation or diminution in volume which takes place, almost with-
out exception, on mixing substances of different specific gravities with each
other, has been usually explained by writers on the subject, as the result of a
powerful chemical affinity between them.

If we admit the ultimate atoms of all bodies to be spherical, by far, certainly,
the most plausible doctrine that has been advanced, and in favour of whiclv indeed
this very phenomenon of condensation, is perhaps, the most decisive proof that
can be adduced, there is no need of any affinity for its explanation.

The amount of the diminution in volume, depends on the specific gravity, or
more correctly, on the difference in size of the ultimate atoms of the substances,
and is in fact, the mere mechanical effect that must be produced by mixing
together spherical atoms of different bulks, and is well illustrated by the following
simple but very striking experiment :

Lead drops of different sizes (Nos. 4, and 10,) were taken as the representa-
tives of two substances of unequal sized atoms.

Into a graduated glass tube, 50 measures of No. 10, and 50 measures of No. 4,
were introduced. Their bulk in this state was of course, exactly 100 measures,
on being well shaken so as to mix them thoroughly, their bulk was reduced to
95 measures, so that a concentration of 5 per cent, had taken place, this amount
was found to vary with the proportions employed.

It maybe objected to this explanation, that some substances on mixture actu-
ally increase in volume, a fact, if true, quite incompatible with the above views.
We believe, however, that more correct experiments will do away with the
greatest number, if not the whole, of these exceptions.

The subject seems worthy of attention, as likely to throw great light upon some
of our chemical theories, even from the above simple experiment of the lead drops,
we think some inferences of the highest importance to atomic chemistry may be
deduced.

1835.]

on Spirits.

257

specific gravity of mixtures of alcohol and water at every
0*5 per cent., and the result of a number of comparative
trials which we have made upon it at different points have
been highly satisfactory.

We have added a table of corrections, to be added or sub-
tracted for each degree. The spirit under trial is above or
below 60°, and will be found to give a sufficiently near
approximation at temperatures between 50° and 70°, and
will be even quite sufficient for a much greater range where
a very great degree of accuracy is not required.

Alcohol

Sp. Gr-

Cor.

Alcohol

Sp. Gr.

Cor.

Alcohol

Sp- Gr.

Cor

Alcohol

Sp. Gr.

Cor.

Alcohol

Sp. Gr.

Cor.

per
Cent.

at

for

per
Cent.

at

for

per

at

for

per
Cent.

at

for

per
Cent.

at

for

60° Fah.

each0

60° Fah.

each0

Cent.

60° Fah.

each0

60° Fah

each0

60° Fah

each0

100-

•79460

48

79-5

•84840

47

59-

•89759

45

38*5

•94213

39

18-

•97382

19

99-5

•79568

48

79-

•84924

47

58-5

•89873

45

38-

•94311

39

17-5

•97443

18

99'

•79716

48

78-5

•85136

47

58-

•89988

45

37-5

•94406

39

17-

•97504

18

98-5

•79845

48

78-

•85248

47

57-5

•90101

45

37'

•94502

39

16-5

•97564

17

98-

•79973

48

77-5

•85369

47

57-

•90215

45

36-5

•94595

38

16-

•97625

17

97-5

•80102

48

77'

•85491

47

56-5

•90328

45

36-

•94689

38

15-5

•97686

16

97'

•80231

48

76-5

•85612

47

56-

•90442

45

35-5

•94782

37

15-

•97748

16

96-5

•80361

48

76'

•85733

47

55-5

•90554

45

35-

•94876

37

14-5

•97806

15

96*

•80490

48

75-5

•85854

47

55-

•90666

45

34-5

•94967

36

14-

•97865

15

95-5

•80620

48

75-

•85975

47

54-5

•90778

45

34-

•95059

36

13-5

•97930

14

95-

•80750

48

74-5

•86095

47

54-

•90891

44

33-5

•95148

35

13-

•97995

14

94-5

•80880

48

74-

•86216

47

53-5

•91005

44

33.

•95238

35

12-5

•98059

13

94-

•81010

48

73-5

•86356

47

53-

•91119

44

32-5

•95325

34

12-

•98124

12

93-5

•81146

48

73-

•86456

47

52-5

•91232

44

32-

•95412

34

11-5

•98188

12

93-

•81271

48

72-5

•86576

46

52-

•91345

44

31-5

•95496

33

11-

•98253

12

92-5

•81398

48

72-

•86696

46

51-5

•91487

44

31?

•95581

33

10-5

•98320

12

92-

•81524

48

71-5

•86815

46

51-

•91570

43

30-5

•95662

32

10-

•98387

12

91-5

•81660

46

71-

•86935

46

50-5

•91680

43

30-

•95743

32

9-5-

•98456

11

91-

•81797

48

70-5

•87053

46

50-

•91791

43

29-5

•95822

31

9-

•98525

11

90-5

•81953

48

70-

•87172

46

49-5

•91896

43

29-

•95902

31

8-5

•98595

10

90-

•82108

48

69-5

•87291

46

49-

•92001

43

28-5

•95979

30

8-

•98666

10

89*5

•82286

48

69-

•87411

46

48-5

•92115

43

28-

•96057

30

7-5

•98739

10

89-

•82465

48

68-5

•87529

46

48-

•92229

43

27-5

•96132

29

7-

•98812

10

88-5

•82594

48

68-

•87648

46

47-5

•92337

43

27-

•96207

29

6-5

•98887

10

88-

•82724

47

67-5

•87767

46

47-

•92446

43

26-5

•96279

28

6-

•98963

10

87-5

•82857

47

67'

•87886

46

46-5

•92554

42

26-

•96351

28

5-5

•99041

9

87-

•82982

47

66-5

•88006

46

46-

•92663

42

25-5

•96421

27

5-

•99120

9

86-5

•83112

47

66-

•88123

46

45-5

•92770

42

25-

•96491

26

4-5

•99201

9

86*

•83242

47

65-5

•88238

46

45-

•92877

42

24-5

•96558

25

4.

•99282

9

85-5

•83371

47

65-

•88354

46

44-5

•92986

42

24-

-96626

24

3-5

•99373

9

85-

•83499

47

64-5

•88473

46

44-

•93095

41

23-5

•96691

23

3-

•99464

9

84-5

•83627

47

64-

•88593

46

43.5

•93200

41

23-

•96757

23

2-5

■99547

9

84-

•83754

47

63-5

•88709

45

43-

•93306

41

22-5

•96821

22

2-

•99630

8

83-5

•83881

47

63-

•88826

45!

42-5

•93408

41

22-

•96886

22

1-5

•99721

8

83-

•84008

47

62-5

•88973

45!

42-

•93511

41

21-5

•96949

21

1-

•99813

7

82-5

•84133

47

62-

•89121

.45 1

41.5

•93612

40

21-

•97012

21

0-5

•99906

7

82*

•84259

47

61-5

•89208

45

41.

•92714

40

20-5

•97074

21

81-5

•84385

47

61-

•89295

45

40-5

•93815

40

20-

•97136

20

81-

•84509

47

60-5

•89411

45 i

40-

•93916

40

19-5

•97198

20

80-5

•84633

47

60-

•89528

45

39-5

•94015

40

19-

•97260

20

80-

•84757

47

59-5

•89643

45

39-

•94115

40

18-5

•97321

19

VOL. I.

258 Dr. Andrew Steel [April

Before leaving this part of our subject, there is another
point which it will not be out of place to determine, the
composition of the spirit, which, in the language of the
trade and revenue, is denominated proof, and by reference
to which, the value of all other spirits is ascertained.

The intention of Government being to levy a certain
amount of duty upon the real quantity of alcohol contained
in spirits, the amount of this duty must necessarily vary
with the strength. In place of taking pure alcohol as the
standard to which the value of such spirits are referred, a
much inferior strength has been, wisely perhaps, made
choice of, as it is of consequence that every standard of this
kind should be that which is most commonly employed,
besides the more important reason, that any small error in
ascertaining the strength, &c, will be of much less conse-
quence in an inferior than in a more valuable spirit.

The proportional value of spirits will be no less truly
ascertained, by reference to the quantity of such standard
spirit, that would be capable of producing or being produced
by that given compound, provided it be certainly and pre-
cisely defined. This, unfortunately, can hardly be said to
be the case.

The first attempt to fix it by parliamentary authority,
was by the 2 G. III. c. xxv., by which it is enacted, " That
each gallon of spirits, of the strength one to six, under hydro-
meter proof, shall be taken and reckoned as seven pounds
thirteen ounces the gallon."

The omission to fix the temperature, coupled with the
awkwardness of describing a mixture, differing from proof
rather than proof itself, and from which the latter could
only be inferred, from a calculation, in which different
data may be assumed, are the leading causes of all the
uncertainty relating to this subject.

Unsatisfactory as this first attempt was, it was contrived
to render it still more so, by the one which succeeded ;
27 G. III. c. xxxi., enacting, " That all spirits shall be
taken to be of the degree of strength, which the said hydro-
meter, called Clark's, shall denote it to be."

This instrument was, perhaps, the very worst that could
have been made choice of, different instruments, varying
not only from each other, but from themselves, to the

1835.] on Spirits. 259

amount, in some of the higher indications, of nine or ten
per cent.

The deficiency of these acts was soon universally ac-
knowledged ; and shortly after the passing of the latter,
application was made by government to the Royal Society,
for the institution under their direction, of a series of ex-
periments, by which the actual relative values of spirits
and the consequent just appreciation of the duties to be
paid by each, might be ascertained.

The experiments that we have already had occasion to
notice were the result of this application. Unfortunately,
however, in place of fixing the value of the (at that time
considered) legal proof spirits, and determining the relative
value of other strengths to this, they thought proper to
propose a new standard, and drew up the result of their
experiments so as to be applicable to this.

Leaving out of view the temporary inconveniences that
would have been experienced by the trade and revenue
officers, from the adoption of this proposal, it would be
difficult to point out any advantage that would have been
gained, by changing the standard from 0*92, to an equally
arbitrary point 0*825, while very satisfactory reasons
might be adduced against it. Hence, though these tables
undoubtedly afforded data' for a very accurate system,
from not meeting the immediate views of Government,
little advantage was taken of them, and the uncertainty in
the standard was allowed to continue.

One more attempt has since been made to overcome this
difficulty, a difficulty, which certainly it is surprising
should have been allowed to remain, in spite of three
successive enactments, for the express purpose of doing
away with it ; since, had a certain specific gravity at a fixed
temperature, been declared to be that of proof spirit, the
question would have been at once clearly and definitely
settled, it remains to be seen, how far this has been accom-
plished by the succeeding act, the one by which proof spirit
is at present defined. The exact words of the act are,

" That an hydrometer, called Sikes, had with great care
been completed, and had by proper experiments made for that
purpose, been ascertained to denote as proof spirits, that which
at the temperature of 51 degrees, weighs exactly twelve thir-
st

260 Dr. Andrew Steel [April

teenth parts of an equal measure of distilled water." 58 G.
III. c. xxviii.

Three different specific gravities may, and have actually
been deduced from the above as that of proof spirits by
different writers, each of which, in one sense, must be
considered as legal, and as agreeing literally with the words
of the act.

This ambiguity arises from the omission to state the
temperature at which the weight of water was to be con-
sidered as unity.

Hence, 1st. by considering this to be intended as 60°, the
legal point at that time, the act is interpreted f3 of 1 =
•92308, the specific gravity of proof spirit at 51° ; hence,
it would be -91921 at 60°.

2nd. By considering 51° as the point intended, we get
•92308 as the specific gravity of proof spirit at 51°. Water
being, at the same temperature, or raising both to 60°, we
get -92003 as the specific gravity of proof spirit.

This last has most commonly been considered as the
specific gravity of the spirits intended to be defined by the
act as proof. That it really is not so, we shall show imme-
diately, but that i? parts of the weight of an equal bulk of
water at 51° considered as unity at 60°, is the legal specific
gravity of proof spirit at 51°. The weight of a given bulk
of water reckoned 1 at 60°, will, by Captain Kater's experi-
ments, weigh 1*0004 at 51°, nearly J| parts of which m
•92338, is the specific gravity of proof spirit at 51°= -91957
at 60°.

From this ambiguity, it is obvious, that our present law,
whatever may have been the intention of its framers, does
not define proof as relates to spirits of other strengths.
It is in fact, with a little alteration in its wording, precisely
of the same import, as that of the 58 G. III. c. xxviii. above
quoted, merely substituting Sikes' hydrometer for that of
Clark's, or in other words, declaring that spirit to be proof,
which is indicated as such, by Sikes' hydrometer; and though
the fact of stating the weight, which trial had indicated such
spirits to be, in terms of itself, in place of one to six under
proof, must have been allowed a great improvement ; the
omission of not stating the temperature of the water has
rendered it quite nugatory. So that in reality, the act

1835.] on Spirits. 261

does not advance us one step to the attainment of our
object, as it simply substitutes one maker's instrument in
place of another, leaving the vast interests depending upon
its indication to the accuracy of the maker, or perhaps, his
workman. We have no other method of settling this dis-
puted point, but that of ascertaining the specific gravity
of spirit indicated as proof at 60° by this instrument.

In different trials, we have found this to vary from *91936
to '91978, or rather, spirits within this range were all
indicated as exactly proof by the hydrometer, evidence
that it is not sufficiently delicate to show very small varia-
tions, but decisive enough in proving, that the specific
gravity deduced by the latter of the above views *91957 at
60°, is that of legal proof spirits, and therefore, containing
by weight, Alcohol . . . 49-2

Water. . . . 50-8

100-0

When it is considered, that by the above act, Sikes'
hydrometer is made a national standard, it becomes in-
teresting to inquire, how far from the accuracy in its
relative indication, or its intrinsic merit, it is entitled to
such a distinction.

This hydrometer like every other, is simply a sp. gr.
instrument, indicating the difference between the weight
of an equal bulk of water, and of the liquid under trial.
In place, however, of being so graduated as simply to give
this, which is all that the instrument is capable of doing,
the whole range of specific gravity which it takes in has been
divided into one hundred parts. This, at the very first, has
the obvious disadvantage of rendering its indication quite
unintelligible, but through reference to a voluminous set
of tables which accompany it, and which give the per
centage as it is called, over or under proof, at every 0*2
of each of these hundred divisions.

There is some difficulty in exactly defining the terms,
over and under proof, which are consequently very often
misunderstood. If we mix 50 measures of proof spirit
with 50 measures of water, from the concentration which
takes place, this mixture will not be 50 per cent, under
proof, but only 49. Again, if to 50 measures of proof

262

Dr. Andrew Steel

[April

spirit, we add water, till the bulk is exactly 100 measures,
such a mixture, in the language of Sikes, will be 50 per
cent, under proof. The term per centage, is in one sense,
therefore obviously defective, since spirit for example of
50 per cent, under proof, is not composed of 50 of spirit
•+■ 50 water, but of 50 spirit + 51 of water.

Knowing the composition of proof spirits, we can easily
calculate the per centage in these terms, of that at any
other specific gravity, and the correspondence of the indi-
cation of the instrument with this, will be a proof of its
accuracy, and vice versa.

The rule for this calculation may be represented generally,
as follows :

Let s=the specific gravity of the liquid under tried.
,, c=its per centage of alcohol.

,, #=the proof spirit it contains per cent, or is capable
of producing.

,, y=the per centage, in the language of Sikes' tables,
2-0325203. S.c.=2.21029jsc = ;c_

X = -

■91957

and y= iqq°£ as the spirit is over or under proof.

Thus, in the case of proof itself, we have

s = 91957, and c = 49*2, consequently,
x = 2-21029 x -91957 x 49-2 = 99.999, and
y = in this case to 0*
The following table exhibits the correspondence between
Sikes' Hydrometer, and the per centage calculated from the
specific gravity by the above rule.

Sp. Gr.

of the spirits

Per Centage
by

Per Centage
Calculated.

Difference.

tried at 60?.

Hydrometer.

•82580

61*5 o.p.

61-71

0-2

•83524

57-1

56-74

0-36

•90925

8-2

8-31

0-11

•91957

oo-o

00-0

o-oo

•93247

10-8 u. p.

10-757

0-043

•93442

l?-7

12-636

0-064

•96350

45-4

44-63

0-77

•97904

71-3

70-14

1-16

•98700

84-4

83-2

1-2

1835.] on Spirits. 263

The result of these experiments on the gravities above
proof must be considered highly satisfactory, as evidence of
the correctness of the instrument in this part of its scale ;
the differences not being greater, than may be allowed to
proceed from inaccuracies unavoidable almost in performing
such experiments. Below proof, on the other hand, the
difference becomes more considerable than can be accounted
for in this way , the error apparently increasing with the
specific gravity of the spirit.

The instrument employed was wet, for the first time, in
these experiments, after being received, warranted, from
the hands of the maker ; we have no reason to suppose,
therefore, any accidental inaccuracy in it or its weights.

In each experiment, the specific gravity of the spirit was
accurately taken, and, in the above table, to allow every
thing in favour of the instrument, we have given that
which came nearest the indication : hence, the difference, as
deduced from the table, is less than a mean of the experi-
ments would have given.

It may, indeed, be said that the error is as probably in
our tables of the composition of spirits, as in the instrument ;
the result of the following experiments, we think, prove
decidedly that this is not the case :

One part, by measure of proof spirit, was mixed with two
parts of water, well shaken, and allowed to stand twenty-
four hours ; it is obvious that, supposing no condensation
to have taken place, the mixture was exactly 66-666 under
proof; but, from the effect of the condensation, would, in
reality, be a little less than this, or 66*5.

The instrument, on trial, gave 68*9. The same experi-
ment was repeated, with exactly the same result, though,
by the weighing bottle, a sensible difference could be
detected in the specific gravity.

The two mixtures were united and well shaken; the
hydrometer still indicated the spirit as exactly 68*9 u. p.
The specific gravity of this latter mixture, by a mean of
several trials, was -97688 at 60°, which, by calculation,
gives 66*533 as the per centage of the spirit, certainly very
near the truth.

A mixture of 25 parts of proof spirit and 75 of water,
was found to be indicated by the hydrometer as 77*6 u. p

264 Dr. Andrew Steel [April

The specific gravity of this mixture was -98187, at 60°,
giving 75*04 u. p., being much nearer the truth than the
instrument.

Other experiments were tried in the same way, but, as
the results were precisely similar, we think it unnecessary
to detail them, as the above, if thought worthy of confi-
dence, are quite sufficient to warrant the conclusion that
this legalized hydrometer is erroneous in its own indica-
tions, at strengths much under its proof point, to the extent
of between two and three per cent.

We venture to give this opinion, even founded as it is on
experiment, with much diffidence, well aware of the diffi-
culty and numerous sources of error that have to be obviated
in an investigation of this kind.

Another fact may be mentioned, however, which very
powerfully supports the accuracy of the above conclusion
viz., that in the re-distillation of low wines and feints, weak
spirits obtained in the processes of the distiller, varying in
strength from 50 to 90 under proof, the quantity of stronger
spirit produced, is considerably greater than they actually
contained, as indicated by the hydrometer. The average
of this excess may be stated at about 3*2 per cent. This
well known circumstance has been usually explained by
distillers as originating from the presence of foreign matter
in these weak spirits, evident, indeed, from their colour ;
its quantity is, however, in general, too trifling to account
for the whole difference, though it will very satisfactorily
explain why the increase is rather greater than the result
of our experiments would indicate.

There is still another defect in this instrument, or rather,
in its tables, giving rise to, perhaps, even more serious
errors than the above, which has been long well known,
though no attempt has been made to remedy it. No allow-
ance is made for temperature ; spirits are charged only by
their per centage, the same at the temperature of 80° as at
30° ; it is therefore obvious, that when both are brought to
the temperature of 60°, the one will have paid a much greater
duty per gallon than the other.

In conclusion, we must remark, that in legislating on any
subject, but more especially when of such importance as
the present, accuracy and simplicity ought to be the points

1835.] on Spirits. 265

aimed at ; from the neglect of the latter, in the existing
law, the former has been compromised.

It would, however, be no difficult matter to substitute a
system possessing both the above requisites; simple, as being
merely a statement of facts, and accurate as far as the state
of Science will enable experiment to approach.

The standard, or proof spirits, should be clearly defined>
and its specific gravity stated at a fixed temperature, and,
probably, for this purpose, 62° Fahrenheit, would be the
most convenient point, as that made choice of by the Com-
missioners for Weights and Measures, and, consequently,
that at which the specific gravity, by altering the decimal
points, gives the weight per imperial gallon in pounds
avoirdupois.

Two very eligible points offer themselves for that of the
standard spirit.

That composed of equal parts by weight of alcohol and
water, or that proportion of the two at which the greatest
condensation takes place.

Though the latter would be the most scientific, the
former, as differing little from the present standard, would
perhaps be preferred.

A simple specific gravity instrument, with the assistance
of tables, containing the value of spirits at every other
gravity, either by considering the proof spirit as unity, or
expressed in per centages as now made use of, but referred
to the same temperature 62°, is all that will be required.

Probably, giving tables constructed on both these princi-
ples would be found a stiU^reater improvement, the former
as affording a very simple means of ascertaining the value
of, or duty to be paid per gallon by spirits of every specific
gravity, the latter as necessary in estimating with facility
the bulk of proof that any other spirit would produce.

Article IV.
Notice of some Recent Improvements in Science.

MINERALOGY.

This science has made rapid progress ever since minerals
began to be arranged according to their strict atomic
composition. In confirmation of this statement, it is
only necessary to refer to the pages of foreign journals,

266 Notice of some Recent [April

and to those of our own country, but especially of the trans-
actions of the Royal Society of Edinburgh. The arrange-
ments, however, which have hitherto been made public, are
not suited to the chemical systems of this country, and it is
therefore, with pleasure that we inform our readers, that
a system of Mineralogy, by Professor Thomson is in the
press, completely adapted to the present state of the science,
both as regards order and description. The following spe-
cies have lately been analyzed, principally on the continent:
1 . Graphite — A beautiful specimen of this mineral from
Ceylon, found in Gneiss in small pieces about the size of a
nut yielded : {Edinburgh Journal, and Journ. der Chem.
oV Erdmann, 1833.)

Carbon . . . .

62-8

Iron

5*4

Silica

21-6

Alumina ....

9-3

Lime . . . * .

0-2

99-3

Anthracite, from the beds of Baconniere at LaChauniere,

gave

Carbon ....

84-7

Water and bitumen

8-0

Iron pyrites . . .

4-3

Earthy matter . .

3-0

100-0
{Ann. des Mines, vi.)
2. Hydro-boracite. — Resembles gypsum, spec. grav. 1*9.
Before the blowpipe melts into a transparent glass, which
does not change on cooling, and tinges the flame greenish.
The mineral is slightly soluble in water, and is readily dis-
solved by nitric and muriatic acids with the assistance of
heat. It contains

Lime . . 13*298 1 atom
Magnesia . 10*430 2 "
Boracicacid 49*922 2 "
Water. . 26*330 3 "

100*000
and its formula is (C + M) B2 + 3 Aq. (Fogg. Ann.)

1835.]

Improvements in Science.

267

3. Spinelle. — M. Hermann khic\\( Bogg. 1831^ has found
this mineral composed of

Silica 2-25

Alumina .... 68*95
Magnesia . . . . 25*72
Peroxide of iron . . 3*48

100*40

4. Pleonaste. — Consists of, according to Abich,

Silica . . . .
Alumina . . .
Magnesia . . .
Protoxide of iron

2*50
65*27
17*58
13*97

99*32

5. Chabasite. — E. Hoffman has given the following ana-
lyses of this mineral, from different localities : (Pogg.Ann.)

Reibendorfal
Bohemia.

Fassathal.

Parsburg.

Sp. gr. 2-127-

Sp. gr. 2*112

Sp. gr. 2-075

Silica . . .

48*18

48*63

51*46

Alumina .

19*27

19*52

17*65

Lime ....

9*65

10*22

8*91

Soda ....

1*54

0*56

1*09

Potash . . .

0*21

0*28

0*17

Peroxide of iron

—

—

•85

Water . . .

21*10

20*70

19*66

99*95

99-91

99*79

6. Radiolite. — Pfaff found this mineral to consist of
(Schweig Seidell xxiii. 394.)

Silica 48

Alumina 27

Soda 10

Magnesia ... * 3

Water 10

98

268 Notice of some Recent [April

7. Humboldtilite. — Kobell finds this mineral composed of

Silica 43-96

Alumina . . . . 11*20

Lime 31*96

Magnesia ... 6*10
Protoxide of iron . 2*32

Soda 4-28

Potash .... 0-38

100-20
and itsformulais5Al.S + 9CS + 3(| M + { F) S2 + NS2

8. Phenakite from Ural. — Colour yellow, or like quartz.
Sp.gr. 2-969 ; crystals rhombohedrons. The angle of the
rhombohedron is very obtuse, being, according to measure-
ment by the common goniometer, 114°. Colour, none.
Before the blowpipe it does not fuse per se. Fuses with
difficulty with borax, and salt of phosphorus. It is found
in Siberia, and has received its name from its resemblance
to rhombohedral quartz, (fcmi; deceiver.) Hardness greater
than quartz, but less than topaz. It contains

Silica .... 54-54
Glucina . . . 45*46

100-00 (Poggendorff Ann.)

9. Magnesia, — protoxide of iron — A mineral thus consti-
tuted has been described by Breithaupt. (Jahrbuch. vi.
1833.) It is brought from N. America, and is accompanied
with uraniferous spinelle. The crystals are imperfect octa-
hedrons ; cleavage uneven and slightly conchoidal ; lustre
semi-metallic; colour deep greyish black, slightly mag-
netic; sp. gr. 4-418—4-420.

Before the blow-pipe infusible, per se. With borax it
behaves like the tetaniate of iron. It consists of protoxide
of iron, much magnesia, a notable quantity of tetanic acid,
and a little alumina.

10. Junclterite. — The crystals of this mineral, according
to Dufrenoy (Ann. des Mines, vi. 273. J are rectangular oc-
tahedrons, with nearly equal faces. Two of its cleavages
are parallel to the diagonal planes of the octahedron, and

1835.] Improvements in Science." 269

form between them an angle of 108° *26; the third is per-
pendicular to the axes of the same octahedron, and lead to
a rhomboidal prism under an angle of 108° 26'. Junckerite
possesses a yellowish gray colour, very similar to certain
varieties of Scheelin. Before the blow-pipe with borax it
forms a yellowish, transparent, green glass. Sp. gr. 3*815.
It was found in the mine of Poullaouen, (Finistere) in small
quartz veins, which traverse the greywacke in which the
mine exists. The name was applied in honour of M . Juncker
the director, by M. Pailette sub-director, by whom the
mineral was discovered. It consists of

Protoxide of iron . . 53*6

Carbonic acid . . . 33*5

Silica 8*1

Magnesia 3*7

Loss 1*1

100-00

Most of the carbonates crystallize in rhombohedrons.
Those which do not, such as the carbonates of barytes,
strontian, lead, &c, possess a crystalline form analogous to
arragonite. Analogy would, therefore, induce us to believe,
that we know only one of the forms of these carbonates,
and that if they were met with in another form, that form
would be a rhombohedron. Junckerite presents a second
example of a carbonate, occurring in the rhombohedral
form, and in that of a right rectangular prism. The car-
bonate of lead crystallizes in the form of a right rhomboidal
prism, under angle of 117°, which differs from arragonite by
only 50 or 55 minutes ; but the sulpho-carbonate of lead,
from Leadhills, described by Mr. Brooke, occurs in rhom-
bohedrons with an angle of 107° 30'.

Dufrenoy considers that this combination is not a dis-
tinct substance, but only a carbonate of lead mixed with
sulphate of lead,* because the two elements are not in de-
finite proportions, and because it would present the third
instance of a dimorphous carbonate, and we should then
have a similar relation between the angles of the rhombo-
hedral carbonates 105° 5', 107°, 107° 30', as with those of the

270 Notice of some Recent [April

right rhomboidal prisms 116° 5', 117°, 118°. He conceives
that the two forms which the substances endued with di-
morphism present, are connected by a law like the two roots
of an equation of the second degree, and that one being
known the other may be deduced from it. The rhomboidal
prism would be according to the few examples we possess,
tbe form corresponding to the rhombohedron. He cites in
favour of this idea, the cases of the fer oligiste, which cry-
stallizes in octahedrons, and iron, which is observed some-
times in the form of octahedrons, and sometimes of rhom-
bohedrons, but he does so cautiously, because he is not
certain of the exact nature of these substances in their
different crystalline states. He remarks, that the specific
gravity of arragonite is a little above that of the carbo-
nate of lime, being 2*9 to 2*7. The specific gravity of the
prismatic carbonate of iron is 3*8, while that of spathic
iron is 3*6. He infers, from these two examples, that
when the atoms are so arranged as to affect the prismatic
form, they are more condensed than when they unite to
form rhombohedrons.

11. Franklinite, according to the analysis of Abich, con-
sists of

Silica -40

Alumina .... -73
Peroxide of iron . . 68*88
Oxide of manganese . 16*32
Oxide of zinc . . . 10*81

97*14
12. Danaite is found in Franconia. It is a gray metallic
mineral, very brilliant. Sp. gr. 6*214. Possesses an
arsenical smell when heated. According to Hayer it con-
sists of

Sulphur 17*84

Arsenic . . . . . 41*44

Iron 32*94

Cobalt 6*45

Loes 1*33

100.00

1835.] Improvements in Science. 271

It has been named in honour of Professor J. Dana.
(Americ. Journ. iv. 386. )

13. Hypochlorite. — This mineral forms a superficial coat-
ing on clayslate. It is associated with native bismuth,
arsenical cobalt, sulphur of arsenic, and quartz. Its texture
is foliated ; cleavage compact or slaty ; lustre slightly
vitreous ; colour green, more or less translucid. Sp. gr.
2-935-3-045. (Ann. des Mines, vi.)

14. — Antimonial Nickel. (Poggendorff Ann. xxxi. 134.)
H. Stromeyer and Hausmann have examined this mineral.
It was found by Volkmar in the Andreasberger mountains,
mixed with calcareous spar, galena, cobalt ore, and resembles
Kupfer nickel, but is easily distinguished by the colour. It
occurs in crystals of six-sided tables; fracture uneven.
The extremities of the tables possess a strong metallic lustre.
The colour of fresh pieces is copper- red, with a strong tinge
of violet. The powder has a reddish-brown colour, and is
darker than the colour of the fracture. It is not magnetic.
Before the blowpipe it gives out neither a smell of garlic
nor sulphur. Heated in a glass tube some antimony
sublimes. Nitric acid separates the sulphur when galena
is contained in it. The solution of this mineral in nitric,
displaced by tartaric acid, gives, with sulphuretted hydro-
gen, an orange coloured precipitate, which is taken up by
potash, and, by reduction with hydrogen, is converted into
antimony. The solution, freed from antimony, affords,
with carbonate of soda, an apple-green precipitate, which
dissolves in ammonia with a sapphire blue colour. It con-
sists, according to analysis, of

Nickel 28-946 - 27-054

Antimony 63-734 - 59-706

Iron 0-866 - 0-842

Sulphuretoflead. . . 6-437 - 12-357

99-983 99-959
15. Plagionite. — The crystals of this mineral belong to
the oblique rectangular prismatic system of Beudant. If we
consider the faces belonging to an octahedron for the
punvictur form, then the faces parallel to the plane of the
two axes are truncatures of the anterior angles. They are
implanted in quartz. Fracture conchoidal. G. Rose has

272 Notice of some Recent [April

termed it plagionite, from (irAay*o<r oblique) in consequence of
the oblique form and inclination of the axis, which measures
107° 32'. It consists, according to Rose, of

Lead 40-52

Antimony . . . 37*94
Sulphur .... 21-53

99-99

Besides simple sulphuret of antimony, in the Wolfsberg
antimonial veins, there are a great many combinations of
sulphuret of antimony and sulphuret of lead in different
proportions, viz : zinkenite, 3 Sb. su. + Pb. su. Plagionite,
Federerz, Bournonite. The two first have only been found
at Wolfsberg. {Poggendorff, xxviii. 421.)

16. Native Litharge has been found half way up the volca-
noes of Popocatepetl and Iztacictualt in Mexico, correspond-
ing exactly in appearance and composition with that derived
from the lead furnaces, (Ann. des. Mines, yi.J

17. Arsenical Pyrites has been analyzed by E. Hoffmann
from four localities :

Sulphur .
Copper .
Bismuth .
Arsenic .
Nickel .
Cobalt .
Iron .
Serpentine

Schneeberg.

Sladming.

Hartz.

Reichenstein.

0-14

5-20

11-05

1-94

0-50

tt

tt

a

2-19

it

tt

it

71-30

60-41

53-60

65-99

28* 14

13-37

30-02

a

it

5-10

0-56

tt

tt

13-49

3-29

28-6

a

tt

it

2-17

102-27

97-57

98-52

98-16

18. Arsenic Ulance. — Karsten found the composition of
a specimen from Marienberg, in Saxony
Arsenic .... 96-785
Bismuth . . . 3-001

99-786
(Schweig. Seidel, xxiii. 390.)

1835.} Improvements in Science. 273

19. Sternbergite. — Zippa finds this composed of

Silver . . . 33-2
Iron .... 360
Sulphur . . . 30-0

99-2
equivalent to 4 F Su. + Ag. Su.

(Poggendorff, Ann. xxvii.)

20. Melanochroite. — This mineral is found in the neigh-
bourhood of Beresow, in the Uralian Mountains, in lime-
stone, where it is accompanied with vauquelinite, phosphate
of lead, quartz, and galena ; colour between cochineal and
hyacinth ; compact ; crystals, rhomboidal prisms, with two
large faces, which gives them a tabular appearance ; edges,
translucent ; streak, brick-red ; sp. gr. 5*75. Before the
blowpipe fuses easily into a brown mass, which assumes a
crystalline structure on cooling. In the reducing flame it is
converted into oxide of chromium and metallic lead. It
consists of Oxide of lead . . 76*36

Chromic acid . . 23*64

100-00

It is obviously, therefore, a subsesqui-chromate of lead.
(Poggendorff, xxviii.)

21. Chrome iron ore, from Baltimore, was found by Abich
to contain, {Poggendorff, 1831.)

Crystallized. Amorphous.
Silica ...... — 00-83

Alumina 11-85 13-85

Oxide of chromium . . 60*04 54*91

Protoxide of iron . . 20*13 18*97

Magnesia 7*45 9*96

99*47 98*52

22 White Arseniate of Iron. — Kersten found a specimen
of this mineral from Freiberg, to consist of

Arseniate of iron . . 70*70
Water : 28*50

(Schweigger SeidcVs Jahrbuch, vi. 182) 99*20

VOL. I. T

274

Notice of some Recent

[April

23. Polybasite.—

H. Rose has analyzed this mineral from

the following localities : —

.

Guarisamny,

Mexico.

Schemnitz.

Freiberg.

Sulphur . » ,

. 17-04

16-83

16-35

Antimony . ,

. 5-09

0-25

8-39

Arsenic . .

. 3-74

6-23

1-17

Silver . .

. . 64-29

72-43

69-99

Copper . .

. . 9-93

3-04

4-11

Iron ....

. 0-06

0-33

0-29

Zinc .

. . o-oo

0-59

0-00

99-70

100-30

100-15
(Poggendorff, xxviii. 156.)

24. Voltzite. — This mineral is found at Pont Gibaud, in
Puy de Dome. It possesses a pearly lustre ; colour rose-
red, or yellow; granular; fracture irregular; softer than
glass ; sp. gr. 3*66. It consists of

Sulphuret of zinc . . 82-92
Oxide of zinc . . . . 15*34
Peroxide of iron . . . 1*84

(Poggendorff, xxxi.) 100- 10

25. — Carbonate of lead and zinc comes from Mount Poxi,
in Sardinia, in the form of small crystals, irregularly grouped
together in rock quartz ; white and translucid ; hardness
equal to calcareous spar; sp. gr. 5*9. It contains
Carbonate of lead, with traces of chloride of lead 92*10

Carbonate of zinc . 7-02

(Jahrbuch, 3d, 1833, p. 335.) 99*12

26. Gahnite, according to the analysis of Abich, consists
of Silica . . . 3*84

Alumina . . 55*14
Magnesia . . 5*25
Peroxide of iron 5*85
Oxide of zinc 30*02

100*10
The specimen was from Fahlun.
27. Blue Arseniate of Copper, (Jahrbuch, 1st, 1833. p. 73.)

1835.] Improvements in Science. 275

from Cornwall, consists, according to Trolle Wachtmeister,
of

Oxide of Copper .

. 35-19

Alumina ....

. 8-03

Peroxide of iron .

. 3-41

Arsenic acid .

. 20-79

Phosphoric acid

. 3-61

Silica and quartz .

. 6-99

Water

. 22-24

100-26
28. Platinum, in Siberia, is found in fine sand. A piece
was obtained at Nischne Tagil, weighing 4 Kilogrammes,
(8 lbs. 13 oz. 4 dr. avoird.) in 1827, and three bits in 1831-32,
the two first weighing 8 kil. (17 lbs. 11 oz.) and the third
5 kils. (11 lbs. 1 oz. 1 dr.) It is accompanied with gold,
osmium, iridium, magnetic iron, chromium, brown oxide of
iron, oxide of titanium, epidote garnet, rock crystal, and
sometimes diamonds. The sand is composed of jasper,
quartz, and greenstone, and likewise small yellow crystals
of rhomboidal, dodecahedrons, resembling chrysoberyl, the
nature of which is not known. Among the rocks which
accompany platinum in the Uralians, serpentine is the most
remarkable. Gold appears generally to exist in the same
rock with platinum. (Journ. de St. Petersburg, 1833.)
" 29. Osmium and Iridium. — Two minerals have been ob-
tained in the Uralians, composed of these two metals. One
found at Newiansk possesses a compound crystalline form,
consisting of the combination of a double pyramid with six
faces, with a right hexagonal prism. It possesses a blue
metallic lustre. Hardness nearly that of quartz. Sp. gr.
19-386—19-471. Before the blowpipe, on charcoal, it does
not decompose. In the matrass with saltpetre a feeble
smell of osmium is observable. It is found in the auriferous
sand of Newiansk, 95 versts to the north of Katharinenberg.
It is also observed at Bilimbajewsk and Kyschtim, and
several other places in the Urals. The crystals of the
variety from Nischne Tagil have the same form as the
preceding. The colour is blueish-gray, analogous to that
of sulphuret of antimony. Hardness about that of quartz.
Sp. gr. 21*118. Before the blowpipe, on charcoal, becomes
black, and loses its lustre, and disengages a pungent smell

t2

276 Notice of some Recent [April

of osmium, which acts upon the eyes. It is found in the
platiniferous sand of Nischne Tagil. It is never associated
with gold.

These two combinations of osmium and iridium, possessing
the same shape, G. Rose considers that the idea of the
isomorphism of the two metals is confirmed. The Nischne
Tagil variety, which contains more osmium than that of
Newiansk, having a higher specific gravity, it follows that
osmium is heavier than iridium. Osmium ought then to
have a higher specific gravity than 21*118. Hence, it is
obvious that Berzelius' sp. gr. 10 is quite erroneous.
( Poggendorff Ann. xxix. 452.)

30. Native iridium has been found at Nischne Tagil, ac-
companied with gold and platinum. It is in grains of the
colour of silver, verging towards yellow, possessing a strong
metallic lustre, and is extremely hard. Sp. gr. 23*5— 23*6.
Insoluble in acids. It is combined with some osmium, and
may be easily fused. ( Breithaupt in Schweigg Journ. 1833.J

31. Chemical composition of Native Gold, particularly
Uralian Gold. — Gold is never found in the earth in a pure
state, but is always combined with more or less silver.

Fordyce examined a specimen from Konsberg, in Norway,
which consisted of 28 gold, 72 silver in the 100 parts.
Klaproth obtained gold from Schlangenberg in the Altai,
64 gold, 36 silver ; and Lampadius, from an unknown lo-
cality, procured 96*6 gold, the remainder being silver and
iron. Boussingault analyzed gold from different places in
Colombia, and found it combined with silver in variable
quantities, but always in definite proportions, viz. : one
atom of silver with 2, 3, 4, 5, 6, 8, and 12 atoms gold.
(Ann. de Chimie, xxiv. and xlv.) G. Rose, while travelling
in Siberia with Baron Homboldt, made a collection of gold
ores for the purpose of determining the truth of the French
chemist's position.

In the Uralian Mountains, gold is found in rocks and
distributed among sand. Previous to 1819, it was extracted
from rock veins, but after this period, the discovery of sand
containing it occasioned the abandonment of working the
rock mines. Gold in rocks is found always in quartzose
veins ; at Beresow, occurring in the form of crystals, and at
Newiansk, in plates, while at Czarewo Alexandrowsk, pieces
are met with which weigh from 13 to 24 livres, (18 lbs. to

1835.]

Improvements in Science.

211

96 lbs. Troy.) Gold produced by the different workings
is assayed in the mints of Katharinenburg, and St. Peters-
burg.

The following table exhibits the composition of gold from
different localities, all being richer than gold from Colombia
and Siebenburg : —

Katharinenburg
Hiel. . . .
Miask . . .
Bogowslowsk
Kuschwa . .
Werch Isetsk
Nischne Tagil
Kaslinski .
Newiansk . .
Do. . . .
Sisersk . . .
Ufaley . . .
Schaitansk
Bilimbajeusk .

Bewdinski . .
Usewoledski .
Bissersk . .

Gold.

Silver.

sand

93-01

6-99

rock

87-40

12-60

sand

93-0

7-00

—

88-80

11-20

—

90-30

9-70

—

92-70

7-30

—

90-73

9-27

—

91-97

8-03

—

91-42

8-58

rock

92-95

7-05

sand

91-78

8-22

—

91-45

8-55

—

95-10

4-90

—

93-54

6-46

—

91-24

8-76

. —

93-33

6-67

—

89-01

10-99

—

88-72

11-28

Before the blowpipe, pure gold and pure silver are readily
distinguished by their fusing into a transparent and colour-
less glass, with salt of phosphorus in the exterior flame.
In the interior flame, if the quantity of silver is small, the
glass is opaline and yellowish, but if great, altogether
yellow and opaque. The native alloys act in the same
manner, but an alloy which contains only £ per cent, of
silver has no action on salt of phosphorus.

When the quantity of silver is small, which can be easily
detected by the golden colour of the alloy, the metals may
be dissolved in a covered capsule, in aqua regia. The greatest
portion is converted into chloride of silver. Decant the
solution and remove the chloride by the aid of a glass rod,
and add a new dose of acid. If the alloy contains more than
20 per cent, of silver, the chloride sticks to the glass, and
gives rise to inaccuracy. The two acid solutions should then
be diluted. The first is only slightly muddy ; for, it appears

278 Notice of some Recent [April

that a saturated solution of gold does not dissolve a notable
quantity of chloride of silver ; the second, on the contrary,
deposits a considerable quantity of this substance. When
the whole chloride has been deposited it should be filtered
and weighed, after being dried and fused in a porcelain
crucible. Evaporate the liquid in a porcelain crucible, to
drive off the excess of chlorine, and when fumes cease to be
given off, treat it with oxalic acid. Place the liquid in a
glass defended by a convex cover, in order that no gold may
be mechanically removed with the carbonic acid, and allow
the glass to remain for 24 hours in a warm place. Filter
the liquid, evaporate to dryness, and pass a stream of sul-
phuretted hydrogen through the solution of the residue in
muriatic acid. A trace of copper is thus separated, and the
iron may be removed by hydro-sulphuret of ammonia.

When the gold contains more than 20 per cent, of silver,
the correct plan is to assay the alloy in a cupel with lead
and silver, and to treat the new alloy with nitric acid, which
takes up the silver only. Gay Lussac shewed that a loss of
silver is sustained to a small extent in, this way, and G.
Rose, to obviate the inadequacy of this plan, tried a num-
ber of others, and at last hit upon one which he considers
better than any other yet devised. Fuse the native gold
in a small porcelain crucible with lead, by means of a lamp
supplied with a double current of air. Digest the mass in
nitric acid ; detach it from the crucible, and place it in a
glass vessel, adding a new portion of nitric acid diluted
with water, in order to dissolve the nitrate of lead ; wash
the residue ; dissolve it in aqua regia ; precipitate the chlo-
ride of silver dissolved, diluting the liquid with water ; fil-
ter the liquor and evaporate to dryness. Dissolve in water,
and precipitate the gold by means of muriate of iron. Sul-
phated protoxide of iron does not answer for the precipita-
tion, because the gold in solution may still contain a little
lead. Dilute the nitric acid solution with much water; then
treat it with chloride of lead, and not with muriatic acid,
which may precipitate part of the lead in the state of
chloride. Place the liquid in a warm place, to favour the
precipitation of the chloride of silver, and when the solution
has become clear, collect the chloride upon the filter which
was used to filter the solution of gold. The minute portion

1835.] Improvements in Science. 279

of iron cannot be appreciated, on account of the quantity
of lead.

Rose has never found platinum and gold associated. He
deduces from his analyses several important consequences.

1 . Native gold does not contain gold and silver in defi-
nite proportions.

2. Gold and silver being thus combined in indefinite
proportions, he concludes that they are isomorphous, an
inference which cannot be deduced with the same certainty
from the identity of their crystals.

3. Native gold always contains silver, copper, or iron.
The smallest quantity of silver was in a specimen from
Schabrouski, which contained *16 per cent, of silver, but

*35 per cent, of copper were present.

4. The specific gravity is in the inverse ratio of the
proportion of silver contained in the mineral.

In general, fused gold has a greater density than native
gold, which, however, may be owing to cavities in the latter.

5. Different specimens from the same locality vary in
composition.

6. Gold found in veins varies in different parts of the
same mine.

7. He finds that the gold from sand contains more silver
than that from veins. The proportion in the former being
89*7 per cent, of silver, and in the latter, 79*1, a fact com-
pletely contrary to the determination of the Russian govern-
ment, for the mining of gold has entirely yielded to the
process of procuring it from sand. (Poggendorff Ann.)

METEORIC STONES.

According to Hofrath Stromeyer, copper exists in all
meteoric masses. He examined specimens from Agram,
Lenarto, Elbogen, Bitburg, Gotha, Siberia, Louisiana,
Brazil, Buenos Ayres, and the Cape of Good Hope, and
found in all of them an appreciable quantity of copper,
varying from 0*1 to 0*2 per cent., and he came to the con-
clusion that the presence of this metal must be considered
as constant a character of these substances as are the nickel
and cobalt, which are found in greater proportion. {Ann.
tier Physik, xxvii. 689.)

Berzelius appears to have entirely overlooked this metal,
in meteoric stones, for, in the analysis of a mass from
Macedonia, he found

280 Notice of some Recent [April

Silica 39-56

Protoxide of iron 13*83 > iq.qq
Peroxide of iron 5*00 5

Alumina 2*70

Oxide of chromium . . 0*50

Lime 1-86

Magnesia ..... 26-30

Oxide of Nickel . . . 0*10

Oxide of manganese . 2-40

Potash 2-08

Soda 1-20

(Kongl. Vetensk. Acad. Hand. 1828, 156.) 95*53

H. Stromeyer examined a mass found at Magdebourg in
1831, the specific gravity of which which was 7*39, and its

constituents, Iron - - - 74-65

Molybdenum 10*19

Copper - - 4-32

Cobalt - - 3-07

Nickel - - 1*23

Manganese 0*01

Arsenic - - 2*47

Phosphorus 2-27

Sulphur- - -92

Silicon - - -39

Carbon - - -48

10-000
Another body found near the Iron Works of Rothehutte,

in the Hartz, afforded, Iron - - 81*14

Molybdenum 1*08

Copper - - 7-69
Cobalt -
Nickel -

Manganese- 0*14

Arsenic - - 1*82

Phosphorus -81

Sulphur - - -62

Silicon - - 1*94

Carbon - - -69

Calcium - -29

(Ann. des Mines, v. 568.) 98*62

\ 2-40

1835.] Improvements in Science, 281

Eaine, — Hermann,1* of Moscow, examined a substance
termed inflammable snow, which fell on the 11th April
1832, thirteen versts from Wolokalamsk, and covered a
considerable space of ground, to the depth of 1 to 2 inches.
Colour, wine-yellow, transparent; soft and elastic, like
gum; sp. gr. 1*1; smelling like ranced oil; burns with a
blue flame, without smoke ; insoluble in cold water ; soluble
in boiling water, upon which it swims ; soluble in boiling
alcohol; dissolves also in carbonate of soda, and acids
separate from the solution a yellow viscid substance, soluble
in cold alcohol, and which contains a peculiar acid. Ana-
lyzed ,by oxide of copper, it gave

Carbon . . 61*5
Hydrogen . 7*0
Oxygen . . 31*5

100-0
Hermann calls it JSaine, signifying oil of heaven.

MINERAL WATERS.

1. Saline Springs. — Boussingault has observed numerous
springs of this nature among the Andes, with iodine in
solution, and has remarked that the inhabitants who em-
ployed the water of such springs for domestic purposes were
free from goitre, a disease extremely prevalent in the ele-
vated parts of South America. They appear indiscriminately
in the ancient and modern strata. The most remarkable
are those of Guaca, near Medellia, in Antioquia, where
the water proceeds from a micacious syenite, covered
occasionally by quartzose sandstone, containing layers of
pyritic lignite. At the village of Samson, on the Rio Negro,
there is a spring which contains so much glauber salt that
it is little used. It consists of

Chloride of sodium - - 43*
Sulphate of soda - - - 53*
Carbonate of soda - - - 1*0
Carbonate of lime - - - 3*0
Iodine a trace

1-
The district of Vega de Supia contains many saline
springs. The principal rock is syenitic porphyry, which

* Pogg. Ann. xxviii. 566.

282 Notice of some Recent [April

possesses traces of iodine. Five wells hold in solution the
following substances : —

Chloride of sodium - -
Chloride of calcium - -
Chloride of magnesium
Sulphate of soda - - - -
Sulphate of lime - - -
Carbonate of soda - - -
Carbonate of lime - - -
Carbonate of magnesia
Iodine

The valley of Magdalena possesses some iodine waters,
and that of Cauca a great number.

On the plain of Mira is situated the base of the volcano
of Cotocaxo. This plain is covered with sand and common
salt, which is most probably derived from the subjacent
trachyte, a rock containing glassy felspar imbedded in a
basis of pyroxene.

2. Water of Songragne. — The temperature of this water
is 74° C. (45J F.) The spring is situated 706 metres (770§
yards) above the Mediterranean, and arises from a sandstone
covered by secondary limestone. The salts present with
their water of crystallization are, according to Berther,#
Sulphate of soda . . . 12*22

Penol.

Muela.

Ciruela.

Mogan Quinchia.

81-

65-

59-

59-

83-

9*

<<

14*

a

a

1-

it

14-

tt

a

a

31-

a

37-

9-

9-

a

13-

a

a

t<

4*

tt

1-

tt

a

5-

tt

2.

8-

a

a

tt

1-

a

trace

trace

trace

trace

trace

1-00

1-05

1-00

1-00

1-00

Sulphate of lime .

. 5-85

Sulphate of magnesia

. . 4-68

Chloride of potassium

. 2-37

Chloride of sodium

, . 74-88

100-00

no trace of bromine or iodine could lb

e detected.

3. Soultz

. — This water has a spe<

jific gravity of 1*2884,

and contains

Chloride of magnesiun

l . 15-84

Chloride of calcium

. 6-19 <

Chloride of sodium

. 10-94

Chloride of potassium

. 2-08

Bromide of sodium

. . 0-50

35-55

Memoirs, 313.

1835.] Improvements in Science. 283

II. Acidulous Waters. — 1. Ueberlingen on the borders of
Lake Constance, possesses a copious acidulous spring, which
has a temperature of 11° to 12°, and a density of 1*002,
containing in the pound of 16 ounces, the following sub-
stances, by the analysis of Herberger. {Journ. de Pharm.
xix. 192.)

Carbonic acid .... 266*6 cubic inches
Azote . 43*3

Proto-carbonate of iron . 43*424 grms.

Proto-carbonate of manganese 3*936 ,,

Sub-carbonate of soda . . 14*600 ,,

Sulphate of soda . . . 39*000 „

Chloride of calcium . . 30*280 „

Chi oride of magnesium . 19*920 ,,

Matter containing azote . 32*600 ,,

Carbonate of lime . . . 88*520 ,,

Alumina 6*000 „

Silica 32*000 „

. . 00-30

. . 00*60

. . 13*45

2*95

. . 7*00

360.880
The ochry substance which it deposits consists of
Hydrous protoxide of iron . 75*70
Oxide of manganese
Extractive matter
Carbonate of lime
Carbonate of magnesia
Silica and alumina

100*00

This water is employed as a tonic.

2. Cramaux. — Its temperature is 4° 5' C. (40° 1' F.) 24

litres (li galls.) analyzed by Lamothe# afforded

Carbonic acid - - - £ vol.

Carbonate of iron - 50 gr

Sulphate of iron - - 12 ,,

Carbonate of lime - 48 ,,

Sulphate of lime - - 24 ,,

Muriate of lime - - 48 ,,

Muriate of potash - 48 ,,

Sulphate of magnesia 7 ,,

Animal matter - - 3 ..

* Journ. de Pliarm. xix. I9S.

240

284 Recent Improvements in Science. [April

3. Acidulous water of Cambon. — M. Blondeau, (Journal
de Pharm. xxi. 674.) finds this water, which is situated in
the department of Cantal, in a clay slate formation to
contain

Bi-carhonate of soda,
Carbonate of magnesia,
Carbonate of lime,
Sulphate of soda,
Chloride of sodium,
Carbonic acid,
Traces of organic matter.
III. Hot Springs. — In the neighbourhood of the volca-
noes of the Cordilleras, according to Boussingault, ' the
temperature of thermal springs does not diminish with the
altitude, from which it would appear, that the heat is
derived from internal fires. They contain carbonates of lime
and magnesia, chlorides of calcium, and sodium, sulphates
of soda, lime, magnesia, traces of silica, carbonic acid,
and sulphuretted hydrogen gases, (Ann. de Chim. 52. 181.)
IV '. Sulphureous Waters. — Waters of St. Genis. — Professor
Lavini procured from a litre (61*02 cubic inches) of this
water, 19*5 cubic centimetres, (1*17 cubic inch) of carbonic
acid, 5 (0*3 cubic inch) sulphuretted hydrogen, and 17*5
(1*05 cubic inch) of azote, and the following solid contents
in the same volume of water:

Silica O0254 grms.

Peroxide of iron- - 0*0066
Alumina - - - - 0*0015
Carbonate of lime - 0*0535
Iodide of sodium - 0*0136
Sulphate of soda - 00151
Carbonate of soda - 0*2733
Chloride of sodium - 2* 1034

2-4924
St. Genis is situated in Piedmont, about 4 leagues to the
East of Turin. The temperature of the water is 5° R.
(44°1 F.) (Memoire della JReale Accademia, delle Scienze di
Torino, xxxvi. 19.)

1835.] On Dysluite. 285

Article V.

On Dysluite. By Thomas Thomson, M.D., F. R.S., &c.
Regius Professor of Chemistry ?n the University of
Glasgow.

The mineral of which I mean to give an account in this
paper, was sent me at least seven years ago, by Dr. Torrey
of New York; and some years after, I received a fresh
supply from Mr. Nutall. Dr. Torrey informed me in his
letter, that it had been discovered by two American Minera-
logists, (I think they were Mr Keating and Mr. Vanuxem ;
though of this I am not quite sure, as I have not Dr. Tor-
rey's letter at hand,) who gave it the name of dysluite, from
its difficult fusibility with carbonate of soda, and who were
engaged in analyzing it. This information prevented me
from doing any thing more than giving it a cursory ex-
amination, which satisfied me that dysluite was a new
mineral of rather a curious nature, and highly deserving
the attention of mineralogists. Being unwilling to deprive
the American mineralogists of the credit which might
accrue to them from the analysis, I cautiously abstained
from alluding to it, in a paper on the analysis of American
Minerals, published in the Annals of the Lyceum of Natural
History of New York, in the year 1828. But six years
having elapsed since that period, and no analysis nor notice
of dysluite having appeared in the interval, I take it for
granted, that the American gentlemen have relinquished
their intention of prosecuting the analysis, and that, there-
fore, I ought no longer to withhold the knowledge of this
curious mineral from mineralogists.

Dysluite occurs at Stirling, in New Jersey, interspersed
through a dark coloured limestone, and immediately mixed
with crystals of octahedral iron ore and several other
minerals, which it is unnecessary to describe here. I ob-
tained it by dissolving the limestone in muriatic acid, and
picking out the crystals of dysluite from the other crystals
and grains with which it was mixed.

Colour yellowish brown, sometimes lighter, sometimes
darker. In grains varying from the size of a mustard seed,
to that of a pea ; most of them crystallized in regular octa-
hedrons. Texture foliated. Lustre of the faces of cleavage

286 Dr. Thomas Thomson [April

splendent, resinous, the faces of the crystals are frequently
rough and have little lustre ; easily frangible ; hardness 4*5 ;
specific gravity 4*551.

Before the blowpipe assumes a red colour but does not
fuse, on cooling it resumes its natural colour and appear-
ance. When heated on charcoal it becomes darker but
does not melt. With carbonate of soda it does not fuse ;
but the soda while in fusion appears red, on cooling it re-
sumes its white colour. With biphosphate of soda it does
not fuse. The flux while in fusion assumes a fine red
colour ; when it becomes solid, the colour changes to yel-
low ; and when quite cold, it resumes its usual colours and
transparency, the assay remaining unaltered in the centre.
With borax it dissolves very slowly. The bead is trans-
parent and has a very deep garnet red colour.

1. To determine the component parts of this mineral,
100 grains of it were reduced to a very fine powder, and
heated for an hour in a platinum crucible with thrice the
weight of anhydrous carbonate of soda. The mixture
had been fused, and when cold had a fine green colour,
indicating the presence of manganese in the mineral. On
digesting the fused mass in muriatic acid, 67 grains of the
mineral remained undecomposed.

This residue was again fused with thrice its weight of
carbonate of soda, and kept for an hour in a strong red
heat ; the fused mass was similar to the former. Being
digested in muriatic acid, 33 grains of the mineral still
remained undecomposed.

These 33 grains being treated with thrice their weight
of carbonate of soda as before, the whole dissolved in mu-
riatic acid, except a few flocks; which being heated a
fourth time with carbonate of soda, and the mixture di-
gested in muriatic acid, a complete solution was obtained.

2. The solution in muriatic acid had a strong yellowish
red colour, shewing that the mineral contained much per-
oxide of iron. They were all mixed together and evapo-
rated to dryness in a porcelain dish.

3. The dry mass, which had a yellow colour, was digested
for an hour in water, acidulated with muriatic acid, and
then passed through a filter. There remained on the filter
a white powder, which, being washed, dried and ignited,

1835.] onDysluite. 287

weighed 2 grains ; dried by the blow-pipe, it melted with
effervescence into a transparent colourless glass with
carbonate of soda, and was not soluble in acids. It was,
therefore, silica.

4. The liquid which had passed through the filter, to-
gether with the washings, was evaporated down to a
manageable quantity. It was then neutralized and pre-
cipitated by caustic ammonia, added in excess. The whole
was thrown on a filter, and the yellowish red residue on
the filter well washed. The colourless liquid which passed
through the filter was concentrated on the sand-bath,
partly to drive off the excess of ammonia, and partly to
reduce it to a manageable quantity ; during the concentra-
tion white flocks fell. The quantity of this precipitate was
much increased on adding carbonate of soda to the liquid.

This precipitate was collected on a filter, washed and
dried. It possessed the following properties :

Q..) When heated to redness, it became yellow, but re-
sumed its white colour on cooling.

(2.) Soluble in sulphuric, nitric and muriatic acids. The
solutions colourless ; and when neutral, possessed the
peculiar taste which characterizes the salts of zinc.

(3.) The nitric acid solution precipitated in white flocks by
caustic ammonia, re-dissolved by an excess of the precipitant.

(4.) Precipitated in white flocks by caustic potash, and
re-dissolved by an excess of the precipitant.

(5.) Precipitated in white flocks by the alkaline carbo-
nates, and not re-dissolved by an excess of the precipitant.

(6.) The sulphuric acid solution being cautiously evapo-
rated, yielded transparent white crystals in four-sided
prisms, almost rectangular, and easily recognizeable as sul-
phate of zinc.

It is obvious that the powder thus obtained was oxide of
zinc.

To the liquid from which this precipitate had been ob-
tained, oxalate of ammonia was added, and the liquid con-
centrated. In this way an additional precipitate was slowly
obtained, which was oxalate of zinc.

All these precipitates being collected and exposed to a
strong red heat, left 16*8 grains of oxide of zinc.

5. The red precipitate collected on the filter, (in para-
graph 4) was well washed, and while still moist, was dis-

288 Dr. Thomas Thomson [April

solved in muriatic acid. This solution was mixed with a
great excess of caustic potash, and boiled for two hours in
a porcelain vessel ; the whole was then passed through a
filter. The liquid which passed through was colourless ;
the matter remaining on the filter was dark red.

6. The potash solution which thus passed through the
filter, together with the washings of the filter, was evaporated
to dryness in rather a strong heat, and the dry residue being
mixed with water, was digested (in the cold) in muriatic
acid. A white powder remained undissolved, which, being
separated and ignited, weighed 13*04 grains. It possessed
the following characters :

(1.) When heated before the blow-pipe with nitrate of
cobalt, it assumed a beautiful blue colour.

(2.) It dissolved by heat in sulphuric acid, and the solu-
tion being mixed with a solution of sulphate of ammonia,
yielded crystals of alum. The powder then was alumina.

7. The muriatic acid solution being supersaturated with
carbonate of ammonia, a white precipitate fell, which being
separated and ignited, possessed the characters of alumina,
and weighed 17*45 grains.

Thus, the whole alumina extracted from the mineral was
30.49 grains.

8. The dark red precipitate which was collected on the
filter (in paragraph 5) being dried and ignited, weighed
50*53 grains.

9. It was digested in muriatic acid. The whole dissolved
except a white powder weighing 0*996 grains. It was silica
slightly impregnated with iron.

10. The muriatic acid solution was mixed with carbonate
of ammonia till it was rendered as neutral as possible ; in-
deed a few flocks had precipitated. It was then heated in
a flask. Carbonic acid gas escaped in abundance, and the
whole peroxide of iron was precipitated. The whole was
thrown on a filter, the oxide of iron was collected on the
filter and washed ; the colourless solution which passed
through being mixed with carbonate of ammonia, a white
precipitate fell, which became brown by strong ignition,
and possessed the character of oxide of manganese. It was
equivalent to 7*76 grains of protoxide of manganese.

11. The peroxide of iron remaining on the filter being
dried and ignited, weighed 41*774 grains.

3835.]

on Dysluite.

289

From the preceding analysis the constituents of dysluite
appear to be

Alumina - - - - -

Oxide of zinc - - -
Peroxide of iron - -
Protoxide of manganese
Silica ------

Water

Atoms.

30-490

13-55

8-

16-800

3-2

1-89

41-774

8-38

4-96

7-760

1-69

1-

2-996

1-498

0-88

0-400

100-12

If we admit the silica to be only an accidental mixture,
it is evident that dysluite consists of
8 atoms alumina
2 ,, oxide of zinc
5 ,, peroxide of iron
1 ,, protoxide of manganese
The alumina obviously acts the part of an acid, as it does
in spinell, automolite, sapphirine, and candite. But in all
of these, several atoms of alumina unite with one of the
bases, which are manganese and peroxide of iron. But
dysluite is composed of simple aluminates, the formula
exhibiting its constitution being

5/A1. + 2ZA1. + mn Al.
It is worthy of remark, that the crystalline form of dys-
luite is the regular octahedron, the same form which spinell
and all the other crystallized minerals, in which alumina
acts the part of an acid, assume.

Note. — The four minerals mentioned, in which alumina
acts the part of an acid in union with a base, have their
composition represented by the following formulae, as
deduced from analyses made in the laboratory at Glasgow.

1 Spinelle, Sp. Gr.

3-523 .

MAI.6

2 Sapphirine ,,

3-428

. 2M A1.6 + MS3

3 Candite „

3-617

8MAl.* + 5/Al.2£

4 Automalite ,,

4-261

. Z Al.6

To which may be added

Chrysoberyl ,,

3-711

. eGLAl.^/AUJ
Edit.

VOL. I

290

Dr. R. D. Thomson on the

[April

gp' Neat's TXtngiie

Great Id.

II og
EUp7,iaUa Id.

§ 9 ^
fl x

I-".' TTo*g»

Rtuer

1 835.] Geology of the Bombay Islands. 29 1

Article VI.

Sketch of the Geology of the Bombay Islands. By
Robert D. Thomson, M. D.

Although Bombay has been known to Europeans since the
year 1509, when the Portuguese Viceroy Ameyda captured
a vessel in what the historian of the time has termed " the
River of Bombaim,"# no connected view of the geological
nature of the islands and antiquities in its neighbourhood
has hitherto appeared. It is with a view of contributing to
supply this omission, that the facts contained in this paper,
which were acquired by observation, in the course of a short
residence in that presidency in 1832, were drawn up.

The mean of fifty-nine observations in May, June, and
July, 1832, gave me 83°* 14' for the temperature of the
harbour of Bombay. This includes twenty-seven observa-
tions made after the setting in of the monsoon, on the 14th
June. But a period of thirty-two days, immediately previous
to this' date, affords 83°-43' for the mean temperature of the
hot season; and twenty-seven observations gave for the
commencement of the rainy season a mean temperature of
82°* 85. The average temperature for 1803 was 81|°, and
for 1804, 80J° ; and the number of rainy days for these
years 102.f

The quantity of rain which fell in June, July, August,
and September 1817, was 104 inches.^ On the 23d June
1817, no less than 93 inches of rain fell in one day. In
fact, the inhabitants of temperate countries can form no
idea of the quantity and force of the rain which falls
between the tropics. The mean barometrical height for
half of 1816 and 1817, was 29'986 inches.

The harbour of Bombay, situated on the Concan, or
Pirate Coast of the western peninsula of Hindostan, is
possessed, as its name implies, of peculiar excellence and
capaciousness,^ and has, therefore, been considered of great
value ever since it became part of the British possessions.
It may be described as forming the southern portion of a

* Sousa's " Portugues Asia," Tome. i. p. 146.

f Ann. of Philosophy, xiii. 145.

t Ann. of Philosophy, xii. 212.

§ From the Portuguese Buon-Bahia, good hay. The accompanying chart of
the harbour and islands of Bombay, I have enlarged from that of Laurie and
Whittle.

u2

292 Dr. R. B. Thomson, on the [April

rectangular bay or recess, which lies between Tull Point in
N. lat. 18° 47', and Basseen, in N. lat. 19° 19', and between
the parallels of E. Ion. 72° 47' and 73° 3', possessing, therefore,
an extreme length of thirty-two miles, and an average
breadth of sixteen miles. The island of Salsette occupies
seventeen miles in the length of the northern part of the
bay, acquiring a breadth of from fifteen to seventeen miles,
while its circumference has been computed at seventy miles.

A considerable proportion of the remaining part of this
bay is occupied by Bombay, Caranja, Elephanta, Butcher,
Woody, and Cross Islands, which, being disposed in a
crescentic manner, form the harbour of Bombay, an open
and extensive bason eight miles in diameter, affording
good anchoring ground and secure shelter for fleets of
ships of the largest burthen. It is these insulated por-
tions of land, that I have designated the Bombay Islands.
The appearance presented by these islands is highly pic-
turesque, as they are in many places adorned with thriving
woods, which, between the tropics, always produce rich
and refreshing scenery. But, in the Island of Bombay, the
present trees appear of recent origin ; for, we learn from
older writers that the land was formerly swampy, and
afforded no plants or trees worthy of mention. At present
the higher parts of Salsette and Caranja are nearly destitute
of trees, but they are for the most part thickly clothed
with straggling jungle.

The general contour of these islands corresponds closely
with that of the adjacent continent, and as far as the latter
has been investigated, the formation appears identical.
The altitude attained by the rocky masses in these insulated
lands is never great, although they are all considerably
elevated above the level of the ocean. The dark hills of
Salsette reach the greatest height, next to them in order
come the rugged masses of Caranja and Elephanta, but
Bombay and the remaining islands approach more nearly
the character of plains.

Before taking a separate view of each of the more con-
siderable of these islands, it seems satisfactory to present at
one view a description of the rocky masses and minerals,
which form their essential constituents, and here it may be
premised, that the rocks belong all to that class which has

1835.] Geology of the Bombay Islands. 293

been termed trappean, or, theoretically, volcanic, as dis-
tinguished from the granitic series, or plutonic rocks.

1. Basalt, occurring in situ at the ruins of a chapel in
Salsette; colour, dark-gray, or blackish, with numerous
crystals of olivine and augite interspersed ; fracture, irre-
gular, dull. The upper portion of the ridges in Salsette
appears to consist of this rock, or modifications of it.

2. Black Basalt, in Elephanta, often presenting a homo-
geneous aspect when fractured, but frequently containing
minute portions of olivine, sometimes in rounded granules,
at other times crystallized ; texture highly indurated. This
and the former variety, fuse before the blow pipe per se
into a mass resembling pitch stone. The celebrated figure
of the elephant, close to the village of Gallipooti, consists
of this rock but it appears to be of limited extent.

3. Amygdaloid, appearing at the great temple of Ele-
phanta, possesses a hard wacke basis, containing cavities
filled with rock crystal and zeolites, &c, some of which
are often met with enclosed in the strong mass in the form
of rounded nodules, whose crystalline structure is not appa-
rent until they are transversly fractured. The rock has a
purplish aspect, and is evidently decaying in many situa-
tions, by the readiness with which the atmospherical influ-
ences act by the medium of the amygdaloidal cavities.
Before the blowpipe per se this rock simulates fused basalt.

4. Yellowish gray claystone porphyry, at the lower cave
of Elephanta. The predominating particles have a yellow
resinous appearance, with a black basis.

5. Green claystone porphyry, appearing at BaboolaTank ;
fine-grained, and admitting of a good polish, interspersed
with dark-coloured soft particles, which have an even frac-
ture, and appear to be small masses of indurated clay.

6. Amygdaloid, with a light coloured, porphyritic basis
and green cavities, accompanied generally with large crystals
of calcareous spar, from the neighbourhood of Parell. The
calcareous spar is sometimes dark-coloured, probably from
the effect of reflected light upon it in its impacted situation.

7. Numerous large fragments of shell conglomerates may
be observed on the shore of Elephanta, consisting of a
nucleus of porphyry, or amygdaloid, closely surrounded by
adhering bivalves, which afford means of extending the
limits of the growth of the mangrove.

294 Dr. R. D. Thomson, on the [April

The amygdaloidal cavities contain numerous species of
various classes of minerals, but those which are of very
common occurrence are included under these genera.

CLASS I. ACIDS. GENUS, SILICA.

1 . Rock crystal, termed Palunca in the Malabar language ;
Spadika in the Grantham dialect, occurs very abundantly in
each of the islands, in the form of crystals, varying from
the most minute size to half an inch in length.

2. Common quartz.

3. Milk and Rose quartz.

4. Chalcedony.

5. Amethyst.

6. Agate.

7. Carnelian, rare in the immediate neighbourhood of
Bombay.

8. Oriental jasper, or blood stone, also rare, but abundant
in Guzurat and Cambay.

CLASS II. — ALKALIES.
I. GENUS LIME.

Calcareous spar.

II. GENUS ALUMINA.

1. Mesolite, whose composition is expressed by the
formula 3 Al. S + (J C + J N) S3 + 3£ Aq. *

2. Heulandite, observed frequently in Caranja and Ele-
phanta, appearing in the form of large white crystals.

Of this last genus the number of species in India will be
found extremely numerous, indeed there can belittle doubt
that this country will afford an immense field of discovery
for future mineralogical investigators, nor is the scantiness
of our mineralogical knowledge of India so much to be won-
dered at, when we reflect that, as yet, scarce a single addition
has been made to our lists from the British possessions in
the East, where, of all portions of the globe, geological
facts point out the certainty of the greatest mineralogical
stores.

The agate occurs in the form of round nodules, as well as
in flat waterworn cakes. The chalcedony forms a basis
generally upon which the rock-crystal and amethyst are
seated, and in one beautiful specimen procured in Caranja,
fine crystals of heulandite are similarly placed. The meso-
lite occurs in large radiated crystals, and likewise in the

* The result of an analysis by me. Jamesons Journal, 1834.

1835.] Geology of the Bombay Islands 295

state of a lump-sugar appearance, which, when fractured,
exhibits minute, slender, silky-like crystals, disposed in a
radiated form.

Carnelian may be procured in the bazaars, brought from
Cambay, where it seems to exist in considerable abundance.
It appears that the specimens of this mineral which are
worked into ornaments, are principally obtained from the
neighbourhood of Broach, by sinking wells in the dry
seasons in the channels of torrents, at the bottom of which
they are found lying in the form of round nodules, inter-
mixed with other rolled pebbles, probably forced by the
impetuosity of the mountain streams from greater eleva-
tions, and generally weigh from a few ounces to two or
three pounds.

Some of them are red, others pink, but the most delicate
and beautiful is certainly the colourless or opaline variety.
There can be little hesitation in affirming that similar sources
of this mineral exist in the beds of the numerous streams
which abound between Bombay and the Ghauts, and which
add so materially to the grandeur of this romantic region.

A beautiful variety is brought to Bombay, containing
elegant arborizations resembling the ramifications of in-
closed mosses, a phenomenon which in many instances
appears to be justly attributable to such a cause. #

Bloodstone, or oriental jasper, as sold in the town by the
Parsees, appears also to be imported from Guzurat, and
the adjacent territories. It is characterized by presenting
a greenish appearance, with numerous blood-red streaks or
veins traversing it in various directions. It is to the latter
species, or to the mock pearls so frequently employed as
ornaments by the inferior castes, that we are to refer the
expression of the historian of Alexander : " lapilli ex auri-
bus pendent." f But with regard to the " Gemmas marga-

* The remark of Pliny, " Infestantur plurimis vitiis — aliis ' capillamentum
rimze simile," with regard to rock-crystal, refers to the presence of Titanite.
Hist. Nat. Lib. xxxvii . c. 2.

The same naturalist ohserves of rock-crystal, " Oriens ethane mittit, sed Imlic.p
nulla praefertur." Hist. Nat. xxxvii. 2. Which is ignorantly denied by Garcias
ab Orto, who was for several years Viceroy of India. He says " Nullo autem
ex praedictis loco crystallus invenitur quemadmodum nee per universam Indiam."
Hist. Arom. et Simplic lib. i. c. 47, p. 171.

t Quint Curt lluf. 1. viii. c. ix.

296 Dr. R. D. Thomson, on the [April

ritasque mare litoribus infundit," it is not easy to give a
satisfactory explanation, although the latter obviously relate
to the pearls of the Indian seas.

We proceed now to a separate sketch of the islands, in
the order of their importance.

BOMBAY ISLAND.

The whole island maybe considered as a plain, variegated
on the east with considerable undulations, which form the
small eminences termed Mazagon, Parell, and Oblong hills.
The southern part divides into two necks of land, of which
the eastern portion, a low and flat surface, affords the site
for the Fort and Dungeree, or the Black Town, and leav-
ing an intermediate space called the Esplanade, terminates
at Mendam's Point, the commencement of the Coulaba
Causeway. The western promontary is considerably elevated,
consisting principally of Malabar Hill, which lies near the
entry of the harbour, and terminates at Malabar Point. In-
cluded between these points, with -a crescentic outline, as
between the prongs of a fork lies Back Bay, a considerable
portion of water, with a sea communication, occupying a
span of 2\ miles, the total mean breadth and length being
about 1| and 1 j miles respectively. The water is shoal,
having a depth of 2J fathoms in the centre, and contains
several sands, sunken rocks, and others exposed- at low
water.

The essential composition of this tract is claystone-por-
phyry and amygdaloid, and in some places, as on Malabar
Hill, basalt shews itself, each corresponding with the varie-
ties described, but seeming to vary with regard to the pro-
portion of the bases and the magnitude of the cavities, and
consequent quantity of the mineral contents. From Men-
dam's Point, a ledge of amygdaloid runs out south-west by
south, to form a junction with Coulaba or Old Woman's
Island, a flat and rocky mass, thinly covered with soil,
which barely conceals the subjacent rocks, bearing every
mark of having been at some period a continuous portion
of that promontary of the island of Bombay upon which the
town is situated. Advantage has been taken of this ledge
to form a connecting causeway between the two islands,
which is left quite dry at low water, so that a free land

1835.] Geology of the Bombay Islands. 297

communication may be kept up in such circumstances. The
prevailing rocks in this little insulated land are the same
as those already mentioned, with the occasional appearance
of basalt as if in dykes. At the southern point a dangerous
rocky mass extends out to sea nearly three miles in length,
assisting, with the aid of Tull Reef, in rendering the mouth
of the harbour extremely narrow, for, if we deduct these
obstructions to navigation, its span is not above four miles,
although the distance from Coulaba to the nearest point of
the continent equals seven miles.

The Coulaba Reef has been termed, from its forked figure,
the Prongs, and appears to consist of the general rock, in
a highly indurated form. The same series occurs at the
New Bunder, by the Apollo Gate, where the amygdaloid
appears to lie over the porphyry, which is very hard when
first exposed, and is employed as a building material. The
New Bunder is formed of it; but notwithstanding the
excellent quality of the stone for enduring the effects of
aqueous friction, it is remarkable that an effectual plan has
not been fallen upon to render the building of the jutty
durable, as it is continually undergoing displacement from
the action of the tide. The utility of the Bunder cannot be
disputed for the numerous ships which annually increase in
frequenting this excellent port, and the situation of this
quay, from its being exterior to the fort, is very important,
and is perhaps safer than the Old Bunder during the height
of the monsoon.

To the north of the town the surface begins to rise
gradually until the small eminence of Mazagon is formed.
Beyond it are Parell and Oblong Hills, all preserving a
rounded outline, thinly sprinkled with cocoa-nut trees,
(Cocos nucifera) and affording some pasture land. At Ba-
boola, a tank has been cut out of the solid rock, supplied
with a broad flight of steps, to enable the inhabitants to
have free access to the water, which they employ for all
purposes. It is from similar reservoirs that the principal
supplies of water for domestic purposes are obtained, and
for the use of the crews of ships visiting the harbour.

As much discussion has taken place with regard to the
influence which water procured from such sources may have
upon the health of seamen, by affecting the alimentary

298 Br. R. D. Thomson, on the [April

canal, and, as the solution of the difficulties of the inquiry
are very closely connected with the geological nature of the
country, a few words upon the subject may not be out of
place here. The whole of the soil which covers the island
being extremely thin, it is obvious that the bottoms of the
tanks, which are several feet below the level of the sur-
rounding surface, must consist of solid rocks, and the mar-
gins being fortified with artificial building, we see that the
water can have little opportunity of acting upon the soft
soil, so as to produce a mixture of the earthy particles, and
hence, that the substances of a saline nature in solution
must derive their origin from the disintegrated rocky mass.
A muddiness, however, generally exists in these waters,
which appears to be produced by the agitation excited by
the natives entering for the purpose of carrying off the
water, and for bathing ; but the proportion of mechanical
mixture thus occasioned does not necessarily exist in general
to any greatly appreciable amount, because, when the cause
of excitement is removed, the commingled matter speedily
subsides. The temperature is always equal or above that
of the atmosphere, and in the dry season may be rated at
from 80° to 86°. It affords the following results with
re-agents : —

1 . A solution of acetate of lead produces a copious white
flocky precipitate.

2. A slight precipitation with oxalate of ammonia.

3. A muddiness with muriate of barytes.

4. A milkiness with lime water.

5. A precipitate with nitrate of silver.

From these facts we may deduce that the water contains
in solution (1.) a quantity of vegetable or animal matter.
Judging by the eye of the relative proportions of the preci-
pitate by acetate of lead in the Thames and Bombay water,
we should be inclined to refer the maximum to the former,
and no one will affirm that the water procured from the
Thames is pernicious to health.
(2.) Small quantities of
Chloride of sodium
Sulphate of lime
Carbonate of lime.
The animal and vegetable matters are derived, there can

1835.] Geology of the Bombay Islands . 299

be little hesitation in concluding, from substances which
readily gain admittance in consequence of the exposure of
the tanks, and the presence of the saline matter must be
attributed to the same sources as in other similar situations,
their small proportions being explained by the want of free
communication between the water and the soluble portion
of the earth.

The rock at Baboola is close grained, and is extremely
hard, approaching in some measure to a green stone, as it
appears sometimes in Scotland, with the aspect of an
aqueous deposit. It affords an excellent material for
mending the roads, which for their smoothness cannot be
surpassed. This rock appears limited in its range ; for at
Parell, amygdaloid occurs with very large cavities, filled
with the usual mineral. The northern portion of the
island is similarly constituted, presenting nearly a level
surface, thickly clothed with a great variety of trees and
shrubs,* which afford a grateful shade from the over-
powering influence of the solar rays, " vim solis umbrae
laevant." The coast is low and rocky with the water gra-
dually shoaling to the land, which at ebb tide leaves a
dry and pleasant beach. The amygdaloid shews itself fre-
quently in the form of half sunk rocks and dangerous
ledges, especially along the Coulaba' shores, but suffering
in the lapse of time from the action of the sea, and occur-
ring remarkably in conjunction with the clay-stone por-
phyry, the latter often rising up between two rounded
masses of the former, sometimes placed above it, at other

* Among the trees of the island, the Ficus religiosa and Indica are the most
stately, which appear to have attracted the attention of Europeans, as early as the
time of Alexander the Great, if we may judge from the admirable description of
Quintus Curtius, " Plerique rami instar ingentium stipitum flexi in humum
rursus, qua se curvaverant, erigebantur, adeo ut species esset non rami resurgentis,
sed arboris ex sua radice generata^." — Q. Curt. Ruf. lib. ix, c. 1.
** Branching so broad and long, that in the ground
The bended twigs take root, and daughters grow
About the mother tree." — Milton.
The variety of trees and shrubs is great, but perhaps, the finest ornaments are,
Morinda citrifolia, Capparis acuminata, Artocarpus integrifolia, Terminalia alata,
Getonia floribunda, Michelia champaca, Mimusops elengi, Gretvia microcos, and
Orientalis, Annona relicula and squamosa, and Tamarindus Indica, which if any
members of the vegetable kingdom can be considered as indigenous in this island,
must hold the highest rank.

300 Dr. R. D. Thomson on the [April

times under it, both being traversed frequently with basaltic
dykes. All these rocks at the shore may be observed
covered with shells, and their surface with a decomposed
powdery matter, which on inspection turns out to be the
basis of the rock crumbling into dust. At the distance of
two miles from the town, many of the shells which abound
so profusely on the sea-shore are calcined, by which pro-
cess, they are converted into caustic lime, which the natives
term chunam, a substance in great request, both as a mor-
tar, and as an edible rolled up in the betel leaf. The latter
habit, which has been denominated by some writers a
luxury, ought rather to be termed a necessary practice, as
we find it prevailing wherever the sole articles of diet are
procured from the vegetable kingdom, the different sub-
stances employed fulfilling the same end, whether it be on
the coral rocks of the Pacific, the arid deserts of Africa, or
the interminable forests of America.

SALSETTE ISLAND. *

The description of the geological structure of one of these
islands, may be said to include almost the particulars of
the whole, but for the sake of greater perspicuity, we have
ventured to consider them separately. The essential com-
position of Salsette, is clay stone porphyry and amygda-
loid, corresponding with those rocks in Bombay, but basalt
occurs in very considerable tracts, and assumes more de-
cided forms. The island is very irregular in its surface,
consisting of ridges and intervening vallies, which in com-
bination afford agreeable scenery.

The basalt forms two ridges which run parallel to each
other, the one on the west and the other on the east of the
narrow strait which separates the island from the continent,
appearing above the amygdaloid which forms the base of the
hills ; and therefore, leading us to conclude, that its ejec-
tion has been subsequent to that of the amygdaloid.

The alteration which the eruption of the basalt has pro-
duced on the masses through which it has been forced, by
rendering the two rocks at the point of contact similar,
and as if passing into each other by a gradual transition,
are sufficiently obvious, but at the same time, the two varie-
ties are as distinct as any of the projected series in general

1835.] Geology of the Bombay Islands. 301

appear, so that in a theoretical nomenclature, (the esta-
blishment of which, it must be admitted, is not for the
advantage of science,) not only the varieties of the trap
formation should be discriminated, but the whole group
should have an appellation, indicative of its production at
a distinct period, and under different circumstances, from
modern volcanoes. The term subaqueous volcanic rocks,
expresses the hypothetical nature of their ejection.

In the centre of the island are situated the celebrated
temples of Salsette, or rather their remains, since they have
received great mutilation, not from the influence of natural
causes, which from the hardness of the rock of which they
are formed, they are calculated in a great measure to with-
stand, unlike the polished remnants of Greece and Rome,
which are daily dissolving in the very rains which nourish
the earth,# but from the hands of barbarous men.

It is not our purpose to describe them ; it is sufficient to
refer to accurate details respecting their appearance and
size, which have afforded subject of admiration to nume-
rous ages.f They are literally caves in hills, composed of
porphyry and amygdaloid, thus differing from the pagodas
on the coast of Malabar which consist of black basalt. %

The Portuguese, who were the first European settlers in
this country, justly merit the high degree of reprobation,
which has been attached to their conduct, in the destruc-
tion of these extraordinary antiquities, for they must have
been infatuated with the most determined intention of mu-
tilation. The date of this dilapidation may be reckoned
about the year 1564, as we learn from the historian of that
period ; that D. Antony de Noronha, the 9th Viceroy, and
23rd Portuguese governor of India, who succeeded John
de Mendo§a in 1564, and held the office till 1567, finding
the people incorrigible, notwithstanding the exertions of

* Davy's Consolations in Travel, Dialogue vi. p. 266.

\ Gemelli Careri, vol. iii. p. 36. Asiatic Society Trans, vol. iv. Sousa notices
a tradition that a subterraneous passage exists between " Canari," and Cambaya,
running under the sea, which was the work of Bimilamansa, who was king of all
that country in the third century. Others attribute the work to the holy prince
Josaphat. F. Antony de Porto, a Franciscan, is said to have travelled for seven
days in this passage, without arriving at its termination. Sousa's Asia, torn. ii.
258, 395.

X Sonnerat Voyage aux Indes, torn. ii. c. 4.

302 Dr. R. D. Thomson on the [April

the religious of the society of Jesus, who had laboured in-
defatigably for the conversion of infidels, and had sent
some of their number into the island of " Salsete," which
contained 66 villages of pagans ; destroyed all their pagodas
to the number of 200. # The soil in this neighbourhood is
highly improveable, if we may judge from the flourishing
appearance of the gardens at Powey, and the quantity of
product raised. In the low valley which runs towards the
centre of the island, the suface is completely covered with
a coating of salt, left by the evaporation of the sea-water,
which periodically inundates the low ground. This salt in
its impure state is employed as a condiment by most of the
natives and naturalized inhabitants of the neighbourhood.
Without drawing any very general or sweeping conclusions,
from the fact of the existence of a recent salt deposit in this
situation, we cannot fail to remark, that an extensive
formation is actually in the course of being produced, for
the product of the disintegrated rocks, will obviously be
spread successively over each saline residuum, and as each
new bed is laid, the subtrata will acquire additional firm-
ness and solidity, combined with the agency of the high
mean temperature, which the most trivial observer will
detect as a powerful agent in tropical countries, in binding
together the most arid particles. f

This valley is formed by a break in the continuity of the
basaltic ridge, the southern portion of which terminates here,
but resumes its altitude and course near Tanna. The vale
is overlooked by the hill which forms the extremity of the
ridge. The ruin of a Portuguese chapel crowns its summit,
consisting of the basalt, (a gray rock with augite crystals
interspersed, which forms its foundation, No. 1.) At the
base of the ridge near the shore is a similar ruin, built of
porphyry, and at each of them there is a corresponding

* " Portugues Asia, by Manuel de Faria y Sousa, translated from the Spanish
by Capt. John Stevens," Lond. 1695, 3 tomes, 8vo., tome iii. p. 14. tome ii.
p. 258. The original title of the work is Asia Portuguesa, 3 torn. fol. Lisboa,
1666-75.

t Some distinguished Geologists have attributed the colour of the red sand
stone to the ferruginous parts of the porphyry, from whose -disintegration, they
consider this formation to be derived. Humboldt Essai geognostique sur le
Gisement des roches, 2nd Edit. Paris, 1826, p. 203.

1835.] Geology of the Bombay Islands. 303

inscription on sandstone tablets, which must evidently have
been procured from a great distance.

The words of the inscription are contracted, and are in
the Portuguese language. They relate to some individual
of the name of Aquias, probably a priest, as the word
sevserdros occurs ; and the dates of the 2d of April 1620,
and 28th November 1630 appear.

Near it is situated a Mahometan garden, neatly laid out
in the English style, with grass walks, flower and vegetable
borders, and a variety of fruit trees.

The ascent to the summit of the hill is rendered difficult,
by the abruptness of the declivity and the loose fragments
containing mesolite, chalcedony and quartz nodules, which
readily yield to pressure, and roll to the base of the hill.
The degradation of rocks cannot better be observed than in
this neighbourhood, where we see them comminuting, roll-
ing to the base and assisting in elevating the level of the
vallies, and diminishing the relative height of the hills, of
which a similarly striking illustration is afforded at the
north-west side of the Pyrenees .# The product of this
disintegration is well expressed by the German epithet,
geschiebe the ratchill of the miners, and must necessarily
constitute the most recent formation wherever it occurs.

From the summit of the hill the prospect is very fine,
the east view being bounded by those extraordinary trap
mountains whose configuration is so well expressed by their
names, Funnel Hill, and the Queen of Mahratta's Castle,
with the connecting ridge of the Ghauts. While, to the
south, the harbour and islands of Bombay appear as if at
the feet, and to the north, the dull high land terminates
the prospect, the foreground being enlivened by the rich
foliage of the Tamarind (Tamarindus Indica) and lofty Pal-
myra, (Borassus flabelliformis) and the more humble,
though not less elegant jungle, consisting of the Ixora,
(Ixora coccinea) Euphorbia, (E. neriifolia), and Lawsonia,
(L. inermis.)

On the north-eastern side of the strait which separates
Salsette from the continent, alow basaltic ridge extends for
four or five miles parallel with the ridge of Salsette, and

* Link's Travels in Portugal, 8vo. 1801, p. 64.

304 Analyses of Boohs. [April

witli the Ghauts, presenting, wherever the rock is unco-
vered, a columnar structure, and in three places, clusters
of columns rise up, some of which are fifty feet high and
twenty inches in diameter, the shafts being variously four
or seven sided. #

( To he continued.)

Article VII.

ANALYSES OF BOOKS.

Philosophical Transactions for 1834, Part II.
( Continued from p. 226. J

II. Intensity necessary for Electrolyzation. — In this part of the
paper the author demonstrates that by producing a ' current by the
action of sulphuric acid upon amalgamated zinc in one vessel, passing
it through acid in a second vessel by platinum electrodes, a current
may pass for a long period, but may be of so low an intensity, as to
fall below that degree at which the elements of water unassisted by
any auxiliary force capable of forming a combination with the matter
of electrodes, separated from each other. He found that a solution
of sulphate of soda can conduct a current of electricity incapable of
decomposing the neutral salt present ; that this salt, in a state of
solution, requires a particular intensity for the separation of its ele-
ments, and that the requisite intensity is superior to that necessary
for the decomposition of iodide of potassium, likewise in solution.
Fused chloride of lead can also conduct a current having an inten-
sity below that required to effect decomposition. Fused chloride of
silver is decomposed by a similar current. A drop of water and
fused nitre conducted a current without decomposition. It appears,
farther, that the necessary electrolytic intensity for water, is the same
whether it be pure, or rendered a better conductor by the addition of
acids, for the power of acids, alkalies, salts, and other bodies in solu-
tion to increase conducting power, appears to hold good only where
the electrolyte through which the current passes undergoes de-
composition.

Currents of electricity produced by less than eight or ten series of
voltaic elements, can be reduced to that intensity at which water can
conduct them without suffering decomposition, by causing them to
pass through three or four vessels, in which water shall be successively
interposed between platinum surfaces.

This subject is worthy of prosecution, in order to enable us to
arrange electrolytes in the order of their electrolytic intensities. In
terminating this portion of his paper, the author observes, in relation
to intensity generally, that when a voltaic current is produced, having
a certain intensity dependant upon the strength of the chemical affi-
nities by which that current is excited, it can decompose a particular

* Ann. of Philosophy, vii. 309.

1835.] Philosophical Transactions for 1834. 305

electrolyte without relation to the quantity of electricity passed, the
decomposition of the electrolyte being produced, if the intensity is too
high. If this be confirmed, then we may arrange matters so that
the same quantity of electricity may pass in the same time into the
same decomposing body, in the same state, and yet differ in intensity,
decomposing in one case, and in the other not.

III. Voltaic Battery. — From the principles laid down, it is
evident that the quantity of electricity in the current cannot be
increased by multiplying the quantity of metal oxidized ; a single
pair of plates, throwing as much electricity into the form of a cur-
rent, by the oxidation of 32*5 grs. of zinc as would be produced by
increasing the quantity of oxidized metal a thousand times. For the
action in each cell is not to increase the quantity set in motion in
any one cell, but to assist in urging that quantity forward, and in
this manner, the intensity is increased, without affecting the
quantity, beyond what is proportionate to the zinc oxidized in any
single cell of the series. Ten pairs of amalgamated zinc and platinum
plates, when acted upon by sulphuric acid, produced such a quantity
of gas as to prove that just as much electricity, and no more, had
passed through the series of ten pairs of plates, as had been trans-
mitted through or would have been put in motion by any single pair,
notwithstanding the consumption of ten times the quantity of zinc.
All these facts tend to shew that the act of decomposition opposes a
certain obstruction to the passage of the electric current, and that
this opposing force is overcome in proportion to the intensity of the
decomposing current. When ordinary zinc is used in a voltaic pile, the
waste of power is very great, for 3^ ounces of zinc, properly oxidized,
can circulate a current capable of decomposing nearly an ounce of
water, and of evolving 2400 cubic inches of hydrogen. This waste,
however, is greater with common zinc than with the pure metal, for,
when common zinc is acted upon by dilute sulphuric acid, portions
of copper, lead, cadmium, are set free on its surface, and form small
but active voltaic circles, which act apparently on the zinc surface,
but, in reality, upon those accidental metals. This effect is removed
by employing amalgamated zinc plates, which afford the full equiva-
lent of electricity for the oxidation of a certain quantity of zinc, but
are active only when the electrodes are connected. This improve-
ment in the voltaic battery is of great importance, for effects of
deecomposition can now be obtained with ten pairs of plates, which
formerly required 500 or 1000 pairs of plates. Dr. Faraday con-
ceives that in further improving the battery, plates of platinum or
silver may very likely be used instead of- copper, in order to avoid
the occasional solution of the copper, and its precipitation on the zinc.
IV. Resistance of Electrolytes to Electrolytic Action. — By
interposing a platinum plate, and adding sulphuric acid to a pair of
zinc and platinum plates, the current was completely stopped, by
requiring it to decompose water, and evolve both its elements before
it should pass. The same effect almost was produced when two pairs
of plates were used, and one interposed plate. But, in the case of
three pairs of plates, a current was induced which passed an inter-
posed platinum plate, but was stopped by two. The current origi-
nated by four pairs of plates was also obstructed by two interposed
vol. i. x

306 Analyses of Boohs. [April

platinum plates. Five pairs of zinc and platinum, with two inter-
posed platinum plates, yielded a feeble current. Six voltaic plates,
and four intervening platinum plates, induced a feeble current.
The effects of retardation were altered when variety was made in the
nature of the liquid employed between the plates, nitric acid appear-
ing to increase the intensity of the current, muriatic acid transmitting
a current more easily than pure sulphuric . acid. Increasing the
strength of the sulphuric acid caused no change in the effect.

On varying the nature of the interposed plate, it was found that
with one voltaic pair and one interposed zinc plate, as powerful a
current was induced as if the interposed zinc plates was absent.
With two amalgamated zinc plates there was still a powerful current,
but some obstruction occurred. On using three intermediate zinc
plates, there was still further retardation, though a good current of
electricity passed. Plates of copper seemed at first to occasion no
obstruction, but after a few minutes the current almost entirely
ceased.

All these retarding effects exhibit most distinctly the chemical
relations and source of the current, and add to the evidence of the
identity of the two.

V. Remarks on the Voltaic Battery. — The action of the battery
is weakened by the formation during its activity of substances which
may even tend to produce a counter current. In an experiment made
by Faraday, the retardation of the current was obviously referable
to the state of the film of fluid in contact with the zinc plate, the
acid of the film being instantly neutralized by the oxide formed.

A second cause of diminution in the force or the voltaic battery is
that extraordinary state of the surfaces of the metals described by
Ritter, which causes them to oppose the passing current.

The author directs, 1st. That weak and exhausted charges should
never be used at the same time with strong and fresh ones, in the
different cells of a trough, or the different troughs of a battery,
because, the plates in the weaker cells retard the progress of the
electricity originating in the stronger cells. 2d. The associating of
strong and weak pairs of plates should be avoided, as one part is apt
to act as an interposing plate.

3d. Reversing tin plates, either by accident or otherwise, has an
injurious effect, by opposing the current in a manner similar to inter-
posed plates of platinum. For, in a series of four pairs of zinc and
platinum plates, in dilute sulphuric acid, if one pair be reversed it
almost neutralizes the power of the whole. Other causes affect the
passage of the electrical current, and there is one especially of com-
mon occurrence, viz : when the copper is precipitated upon the zinc
in the cells.

Dr. Davy's paper on the Torpedo oculata and diversicolor,
termed indiscriminately by the Maltese, Haddayla, contains some
experiments on the electricity of these species of animals, which
establish the anticipation of Faraday, that by the application of
Harris's electrometer to the torpedo, the evolution of heat would be
observed. In his experiments detailed in a former volume of the

1835.] Philosophical Transactions for 1834. 307

Transactions, it was demonstrated that the electricity of the torpedo
is capable of acting like voltaic electricity in effecting chemical de-
compositions. He enumerates at present all the tests or indications
of the electricity of the torpedo now known, which are : 1st, the
philosophical effect, as the sensation it imparts is sometimes called :
2d, the chemical effects, as the precipitation of iodine, the decompo-
sition of water, &c. : 3d, its effect on the thermometer, galvanometer,
and on steel in the spiral. These tests are, in point of delicacy, in
the order in which they are enumerated. Dr. Davy has been unsuc-
cessful in his attempts to elicit a spark from the torpedo, although it
has been said that a spark has been obtained from the Gymnotus
electricus.

With regard to the seat of the electrical power, it appears that
when the brain has been divided longitudinally, the fish has conti-
nued to give shocks. When the brain was completely removed the
fish instantly lost this power. Humboldt stated that a shock may be
procured by touching only one surface of the fish, but Davy finds
that it is necessary to touch the opposite surfaces of the electrical
organs, or a conductor or conductors connected with them, before a
shock can be received. On some occasions a shock was received when
only one surface was apparently touched, but in that case the dis-
charge probably took place through the water, and when one surface
is touched, the animal instinctively makes an effort to bring the other
surface in contact with the offending body.

There appears, however, to be no connexion between the muscular
and electrical power. Two views may be taken of the phenomenon.
It may be considered either, 1st, a form or variety of common elec-
tricity ; or 2d, a distinct kind ; or 3d, not a single power, but a com-
bination of many powers. The first opinion is supported by Dr.
Faraday. The only objection to it is the interruption of the torpedinal
electricity by the smallest quantity of air, and its want of the power
and attraction of the air, which affords some foundation for the
second idea.

The origin of the electricity of the fish may also be urged as an
argument for its specific nature, but without much plausibility,
because, we are ignorant of its cause and nature. The third opinion
may serve as a guide for more minute investigation. The author
suggests that other varieties of electricity may owe their effects to
the union of several powers, or ethereal fluids, and their peculiarities
to the predominance, in various degrees, of these fluids. Dr. Davy
found the skin covering the electrical organs, deeper coloured and
thicker than below, more vascular, with stronger muscles, and more
mucus, the under surface having a greater supply of cutaneous
nerves, and a blood-vessel enlarged into a little bulb, situated one
on each side of the porta, below the plexus of nerves supplying the
the pectoral fin, the use of which may be to propel the blood into the
pectoral fin and electrical organ.

The only remaining paper connected with electricity, in this por-
tion of the Transactions, consists of an account of experiments by
Mr. Wheatstone, on the velocity and duration of electric light. In

x2

308 Analyses of Books. [April

1747 Dr. Watson found discharges through a circuit of four miles in
extent, two miles through wire and two through the ground, to be
apparently simultaneous. Mr. Wheatstone repeated a similar expe-
riment, substituting for the imperfect judgment of the eye, a revolv-
ing mirror. This instrument revolved 800 times in a second, and
during this time the image of a stationary point would describe 1600
circles ; the elongation of a spark through half a degree, a quantity
obviously visible, and equal to one inch seen at the distance of 10
feet, would therefore indicate that it exists the 1,152,000th part of
a second. The deviation of half a degree between the two extreme
sparks, the wire being half a mile in length, would indicate a velocity
of 576,000 miles in a second. This estimation is on the supposition
that the electricity passes from one end of the wire to the other : if,
however, the two fluids in one theory, or the disturbances of equili-
brium in the other, travel simultaneously from the two ends of the
wire, the velocity measured will be half that in the former case, or
288,000 miles in a second. The greatest elongation of the sparks
was 24", indicating a duration of about the 24,000th part of a second.
The general conclusions which the author draws from his experi-
ments are, 1st, The velocity of electricity through a copper wire
exceeds that of light through the planetary space. 2d, The distur-
bance of electric equilibrium, in a wire communicating at its extre-
mities with two coatings of a charged jar, travels with equal velocity
from the two ends of the wire, and occurs latest in the middle of the
circuit. 3d, The light of electricity in a state of high tension, has
a less duration than the millionth part of a second. 4th, The eye is
capable of perceiving objects distinctly which are presented to it
during the same small interval of time.

Physics, 8fc.

Mr. Hamilton's paper on a general method in Dynamics is a most
elaborate one. He shews that in the method formerly employed to
develope the laws of motion, the determination of the motion of a
free point in space, depends on the integration of three equations, in
the ordinary differentials of the second order, and the determination
of the motions of a system of free points attracting or repelling one
another, depends on the integration of a system of such equations, in
number threefold the number of the attracting or repelling points,
unless we previously diminish by unity this latter number, by consi-
dering only relative motions. Mr. Hamilton's method is to reduce
the problem to the search and differentiation of a single function,
which satisfies two partial differential equations of the first order,
and of the second degree, and every other dynamical problem respect-
ing the motions of any system, however numerous, is reduced, in like
manner, to the study of one central function.

Mr. Ivory demonstrates that the beautiful theory of Clairaut,
which assumes for the foundation of its superstructure, a mass of
fluid in equilibrium, and that the pressure of every new stratum
upon the surface of which it is laid, is caused solely by the forces

1835.] Philosojjhical Transactions for 1834. 309

in action at that surface, is very satisfactory when no cause of
motion emanates from the fluid itself, and all the forces in action
depend merely on the place of a particle, but is defective when ap-
plied to fluids consisting of particles that act upon one another by
attraction or repulsion ; Clairaut having omitted to attend to the
attraction of the stratum, which is not infinitely little in its effect
upon the motion of a particle, and is expressed by the difference of
two definite integrals. The correction of Clairaut's theory is very
important ; because, to him belongs an essential part of the theory of
the earth, and he was the first that entertained correct notions
respecting the effect to alter the form of the terraqueous globe, pro-
duced by heterogeneity in its structure. In the theory of the French
philosopher, the equations of the upper surface of the fluid, and of
all the level surfaces underneath it, are derived from the single
expression of the hydrostatic pressure, and are dependant on the
differential equation of the surface.

They require, therefore, that this latter equation be determinate
and explicitly given ; and, accordingly, they are sufficient to solve
the problem, where the forces are known algebraical expressions of
the co-ordinates of the points of action, but they are not sufficient
when the forces are not explicitly given, but depend as they do in
the case of a homogeneous planet on the assumed figure of the fluid.
In the latter case, the solution of the problem requires farther, that
the equations be brought to a determinate form, by eliminating all
that varies with the unknown figure of the fluid.

The author establishes a theory on the subject, applies it to the
principal problems of the equilibrium of a homogeneous fluid at
liberty, and demonstrates that the figure of equilibrium of a homo-
geneous planet can be no other than an oblate elliptical spheroid of
revolution.

Mr. Barlow draws the following inferences from the results of
various experiments made to determine the efficiency of paddle-wheels
of steam-boats, so constructed as to make the floats enter and leave
the water nearly in a vertical position, as compared with common
wheels, and with relation to the consumption of fuel: 1. When the
wheel is but slightly immersed, little advantage is gained by the
vertically acting paddle: 2. When deeply immersed, the vertical
paddle has considerable advantage over the common wheel.

3. When the position of the common wheel is vertical, it affords
less resistance to the engine, and is less effective than in any pa t
of its revolution, which is exactly reversed in the case of the new
wheel.

4. In any wheel, the larger the paddles the less is the loss of
power ; because, the velocity of the wheel is not required to exceed
that of the vessel in so high a degree, in order to acquire the resist-
ance necessary to propel the vessel.

5. With the same boat and the same wheel no advantage is gained
by reducing the paddle so as to bring out, as it is called, the full
power of the engine, the effect produced being merely to increase
the speed of the wheel, and ^consume steam to no purpose.

6. With the same boat and the same wheel the speed will be

310 A liaises of Books . [A f in i .

increased by diminishing the diameter, or by reefing the paddles,
the increase of speed being in the ratio of the square roots of the
radii, or the cube roots of the powers employed. This is important
in long voyages, where the immersion of the paddles is great, in
consequence of the quantity of coals with which steam vessels are
required to be laden. An increase of speed will be given, amounting
to nearly one mile per hour, by reducing the diameter of the wheel
so as to allow the engine to perform its full duty.

7- An advantage would be gained by a wheel of large diameter,
as far as the immersion of the paddle produced by loading the vessel
is concerned, as it would not so sensibly affect the angle of inclination
at which it entered the water. But, to have large wheels, it is
necessary either to have the engines made with long strokes, or to
have the paddle-wheel on a different shaft, in order to diminish the
speed.

Anatomy and Physiology.
Sir Charles Bell, in his paper on the brain, begins by enumerating
some of the impediments which have retarded the discovery of the
structure and functions of that organ. 1. The nature of the inquiry,
since opposite results must be expected in making investigation upon
a subject so delicate. In practice, we find effects produced by causes
which seem quite inadequate. The presence of a small specula of bone
will sometimes be attended by no consequence, and at other times will
give rise to violent convulsions. 2. The disturbance of its circulation,
for no organ depends more intimately upon the condition of the circu-
lation within it than the brain. 3. The most frequent source of
error is the obscurity which hangs over the subject, for not one of
the grand divisions of the brain has yet been distinguished by its
function. Hence have arisen imaginary theories which always tend
to bury a science in obscurity. The present inquiries of the author
are directed to the prosecution of the fact discovered by himself, that
the nerves of motion and sensation originate from different sources.
He follows up these tracts ; marks the portion of the brain to which
they ultimately tend ; ascertains the effect of diseases on these parts,
and compares the system with the anatomical details. The conse-
quences which he has drawn from this investigation are : 1st, that
sensibility and motion belong to the cerebrum : 2d, that two columns
descend from each hemisphere, one of which, the anterior, gives origin
to the anterior spiral roots of the spinal nerves, and is dedicated to
voluntary motion ; the other sends out the posterior roots of the
spinal nerves, and the sensitive root of the fifth nerve, and is the
column for sensation : 3d, that the columns of motion which come
from different sides of the cerebrum, join and decussate in the me-
dulla oblongata, and that the columns of sensation also join and
decussate in the medulla oblongata: 4th, that these anterior and
posterior columns bear, in every circumstance, a very close resem-
blance to one another, agreeing in their sensorial expansions, being
widely extended in. their hemispheres, and in every respect, except in
the nervous filaments to which they give origin.

1865. Philosophical Transactions for 1834. 311

The anatomical descriptions are illustrated by drawings, which will
be found particularly serviceable in unravelling, as far as anatomy
can at present carry us, some of the intricacies of the cerebral organ.
The pons varolii, we observe, in an especial manner, has received
much attention from the distinguished author.

The generation of Marsupial animals, which constitute a distinct
tribe of mammalia, of which the kangaroo and opossum are the prin-
cipal members, has hitherto been involved in much obscurity. But
Mr. Owen, who has been fortunate enough to have it in his power
to examine the gravid uterus of a kangaroo, has observed some im-
portant facts. The genera of this tribe are characterized by possessing
a double uterus, and the true vagina is separated either wholly, or
for a considerable extent, into lateral canals, while the digestive and
generative tubes both terminate within a common cloacal outlet. In
these respects, therefore, they approach the oviparous vertebrata.
The foetus examined by the author was contained in the left uterus.
No placental structure could be observed. The chorion was very
thin. A transparent amnios enveloped this foetus. The umbilical chord
was two inches in length ; the uterus two inches in length, and above
an inch in diameter. No perceptible trace of an allantois or urinary
bladder could be detected ; but in another foetus two weeks old, a
urachus was detected. The author concludes from the observations
of others, coupled with his own, that the ovulum quits the ovisac
as in ordinary mammalia. In the kangaroo uterine, gestation
continues 39 days ; in the opossum 26 days. The former has been
determined with certainty in the Zoological Gardens, and therefore,
overturns the statement of Hilaire, who made the period 4 months.

With regard to the relation between the size of the umbilical
vesicle, the least vascular placenta and a corresponding simplicity of
brain, it appears that in the kangaroo, although shortly after birth the
brain resembles in structure that of the lowest vertebrata, yet it
afterwards assumes a more complex form than that of the opossums
or dasyures. The individuals of the marsupial tribe seem low in in-
telligence, never manifesting any sign of recognition of their keepers
or feeders, and being unable to utter vocalized sounds. When they
are irritated they emit a wheezing or snarling guttural sound, the
necessary apparatus for producing vocalized sounds being absent.
In this respect they resemble the reptilia.

In the author's communication on the ornithorhyncus para-
doxus, this idea of similarity and that lactation might co-exist with
a mode of generation essentially similar' to that of the viper and sa-
lamander is fully confirmed. The regular gradation is traced which
exists in different orders of mammalia, in which true viviparous or
placental generation takes place, towards the ovo-viviparous or ovi-
parous modes, in which the exterior covering of the ovum never be-
comes vascular. The ornithorhyncus is shewn to constitute a con-
necting link in the chain. Both of these papers are accompanied by
plates.

Mr. Lister has observed the existence of currents within some

312 Analyses of Books. [api*l

zoophytes.* In the Tubular ia indivisa, a current of particles was
seen within its tube, which, in its combined and steady flow, resem-
bled the circulation in plants of the genus chara. The general
course of the stream was parallel to the slightly spiral lines of irregular
spots on the tube. Between the stomach and the mouth a remark-
able action was observed. The mouth became swollen by a flow into
it from the stomach, which continued for about a minute. The con-
tents of the mouth were then squeezed back into the stomach, and
during this reflux the connecting orifice was seen distinctly open, and
it continued so till the stomach became nearly empty. The orifice then
closed gradually, preparatory to the effort of forcing the fluid back to
the stomach. Two currents were continually going on both in the
mouth and stomach, one flowing down the sides and an opposite one
in the axis.

These observations were made by a microscope which magnified
100 times, and drawings were taken by a camera lucida slid over the
eye piece.

In the Sertularia pluma Ellis, a current was observed following
in the channel backwards and forwards through the main stem and
lateral branches of a pluma, and might be compared to the running
of sand in an hour glass, five ebbs and flows occupying 15 J minutes.
When the connexion of a plume with the root was interrupted by
bending its stem, the stream running down the middle was observed to
continue its flow up one of the lower and stronger lateral branches,
and then to return down that branch and up the main stem. The
section of a stem made below the commencement of the side branches
exhibited a small stream apparently followed by viscid matter. Ca-
volini first observed this, but no subsequent writer has noticed it. In
Sertularia pumila, an irregular motion was noticed in the stomach
and mouth, and likewise, but not distinctly, in S setacea, dichoma,
and in species of Campanularia.

In a small Ascidia occurring on the conferva elongata, circula-
tion was observed through the transparent coat, the particles of the
blood not exceeding 00025 inch in diameter. The blood enters the
heart from the peduncle, the ventricle contracts in the middle and
drives the fluid into the branchial organ, and into a network of vessels
over the stomach and intestines. After the circulation has gone on
for a while, the pulsations become fainter and gradually cease when
the current is reversed. A Polyclinum exhibited also internal mo-
tions.

In Cellularia and Flusira none of the internal currents which
ill the sertulariae connect the different parts of the zoophyte were ob-
served, nor was any circulation detected. Each animal is enclosed
in its cell, and sends out its mouth and arms through a valve. A
short sheath precedes them, from whence the arms rise straight to-
gether, and then open to a funnel-shaped figure of beautiful regu-
larity, serving probably to draw food to the mouth by currents. Be-

* The useof this term has been much reprobated by Lamarck, but notwithstand-
ing his censure it still continues to be employed by many distinguished naturalists ;
and it is sufficiently expressive of a class oi beings whose nature is st 11 involved
in great obscurity. — Edit.

1835.] Philosophical Transactions for 1834. 313

tween the animals of these genera no line of distinction could b
detected. From these physiological observations, corrections may be
brought about of the arrangement of many species. The Serialaria
lendigera he removes from the Sertulariat and the Anguinaria
anguina from the Tubular ids to the Cellular polypi.

In the paper of Mr. Newport, a minute detail is given of the ner-
vous system of the Sphynx ligustri during the latter stages of its
pupa and imago states, and on the means by which its developement
is effected. During the passage of the insect from the larva to the
pupa state, the gauglia and nervous cords undergo great changes
both in their form and situation, and likewise in their number ; and
after these changes have been carried to a certain extent they are sus-
pended for several weeks, during which the insect hybernates. At
the end of this period the changes again proceed. The insect re-
mains in the pupa state about 43 weeks, and during this period the
concentration of the nervous system proceeds to a much greater ex-
tent. The author describes the double origin and connexions of the
nerves distributed to the wings, the object of which appears to be, to
establish a harmony of action between the wings in those insects es-
pecially, which are remarkable for velocity and power of sight, a dif-
ferent structure being adopted in those which fly with less regularity
or speed.

A pneumogastric nerve or par vagum is described, which is dis-
tributed to the organs of digestion and respiration. The author like-
wise notices lateral cephalic ganglia, which may be regarded as aux-
iliary brains, and a sympathetic nerve ; besides a set of nerves which
appear to correspond with the respiratory nerves of vertebrated
animals. The primary longitudinal nervous cords of insects are
shown to consist of two tracts, the one situated over the other, cor-
responding to the two columns of which the spinal cord consists in
vertebrated animals ; the one forms the seat of sensation, and the
other of motion. The same observation has also been made upon
the lobster, Scorpion, and Scolopendra, and in several insects, as
the Gryllus viridissimus, the Carabus, and Papilio urticae.

Such are the principal papers of which this portion of the Philo-
sophical Transactions consist. The substance of Mr. Powell's paper,
with additions, is inserted in a preceding part of this Journal. It is
rather remarkable, that with the exception of a short notice of a
mineral water, there is no purely chemical paper contained in it.

Article VIII.

SCIENTIFIC INTELLIGENCE.

I. — Employment of Gypsum in Agriculture.

Gypsum has been employed in Switzerland, Germany, England,
and North America for many years as a manure, but it was only
brought into use in France about forty years ago. At present it is
very generally used in that country, with the exception of the de-
partments of Gard and Herault. {Ann. des Mines, vi, 193.)

314 Scientific Intelligence. [April

For the purposes of agriculture it is sometimes calcined, which
deprives it of its water of crystallization, which in the hydrous gypsum
amounts to 2 atoms. This preparation is attended to in France,
where the expense of the process is less than in other countries. In
England, Germany, &c. it is generally employed in the crude state.
The effect which calcination produces, is to render the gypsum more
rapid in its operation, though the beneficial effects are less durable.
In France it is burned in a kind of lime kiln by means of coal, after
being reduced to powder.

It can be obtained in this state in Gard, for one shilling the 110
lbs. avoird., and it costs double the expense in Alais. Extensive
natural deposits occur in England in the neighbourhood of the
Humber, from whence it is brought to Glasgow and Manchester for
the use of the bleachers, who now employ it in considerable quantities.
Its purity may be negatively tested by vinegar, which, if it causes no
effervescence, shews that there is no carbonate of lime present. If it
swells up when water is thrown on it, and then assumes consistence,
it is a sign that it has been properly calcined. The best plaster will
absorb the greatest quantity of water. It is chiefly on artificial
meadows that we observe the best effects from its application, anore
especially on clover, lucern, sainfoin, and in general on the legumi-
nous tribe of plants possessing large and thick leaves. It has a
powerful effect also upon natural meadows which contain much clover,
vetches, and other analogous plants ; but upon the grasses the effect
of gypsum is trifling. It acts, according to M. Thibaud, by extracting
the moisture from the air, and stimulating the vital action of plants.

It sometimes doubles the product of clover, lucern, and sainfoin.
In France it is sowed like corn with the hand, about March or April
when the plants are a few inches above the soil, so as to allow the
gypsum to fall on the leaves- It should be done previous to rain,
but not during the fall of rain, or the existence of wind, or during
frost.

The quantity of gypsum applied to the land must vary of course
with the nature of the soil. In the course of fifteen or twenty days
the good effects resulting from its use are visible, if circumstances
have been favourable. The benefits of one application last for two
or three years, so that it is unnecessary to spread it every year. In
Gard and Herault sainfoin is principally cultivated for pasture, and
seems to thrive well in dry soils, especially in stony calcareous situa-
tions. About Alais, for the cultivation of this plant in artificial
meadows, the ground is first plowed in November, then again in
December, and the seed is sown in the beginning of April.

In Provence and in the southern parts of Languedoc, where the
effects of frost are less dreaded, it is sown in Autumn. The sainfoin
thus cultivated in inferior soil affords one or two crops in the year,
and lasts for four or six years ; then it is plowed up and corn is sub-
stituted for it. It is worthy of remark, that lands which previously
could not produce corn, has, by the use of gypsum in the manner
described, been able to raise good crops in the midland parts of
France. The agriculturists of Alais may procure gypsum from
Anduze, Salle, Roehcbelle, and Blanaves. To Drome it mav be

1835.] Scientific Intelligence. 315

curried from Gard arid Ardeche. At Herault it may be obtained at
Cruzy, Quarantc, Calzouls, Herepian, Beziers, Clermont, Loubes,
and Lodeve. It is extensively employed in Canada with the most
happy results. It was tried in Yorkshire by Lord Dundas without
any benefit, but the soil upon which it was spread was ascertained to
contain a quantity of gypsum. It might be employed, there can be
little doubt, with great advantage in the border counties, where the
trifolium pratense has in many places failed. This plant neces-
sarily from its strong and luxuriant nature, obviously must require
a considerable quantity of the manure. If it be deficient in quantity
the plants may vegetate, but must speedily perish from the effect of
the first frost on their delicate structures.

II. — Royal Institution. — Comparison of the Newtonian and
Undulatory Theories of Light. — 30th January.

Dr. Ritchie commenced his lecture on the two theories of light
which have been advocated by different philosophers for many years,
with a few observations with regard to the difficulty of acquiring
knowledge of the subject by direct experiment, in consequence of the
almost spiritual nature of the substance upon which it is necessary
to operate.

Newton whose opinion was long in vogue, having had his atten-
tion directed to the motions of bodies, considered light as a sub-
stance consisting of revolving spherical particles issuing from luminous
bodies moving in straight lines, and producing reflection or re-
fraction according as the extremities of the spheres, which came in
contact with a denser- medium, were sharp or obtuse. This theory
required certain postulates which appear, however, to be entirely gra-
tuitous. By the undulatory theory, which is often called the theory
of Huygens, which was suggested to his mind in consequence of Ins
attention being directed to the motions of the pendulum, although it
was known before his time, light is considered to consist of the
undulations of an ethereal fluid filling all space, and existing between
the particles of bodies. If such a fluid does exist, we might expect
that it would act in retarding the motions of the heavenly bodies.
It is obvious, however, that the planets can suffer no retardation,
because, in consequence of their revolutions, the ether will also acquire
motion and be carried along with them, but in reference to the comets,
which are extremely light bodies, we find a decided retardation, which
after making all allowances, can only be accounted for on the sup-
position of the existence of an etherial medium. This has been
clearly proved by Sir John Herschel, in his article on light in the
Encyclopaedia Metropolitana. Dr. Ritchie stated that he had only be-
come a convert to the undulatory theory of light about two years
ago, in consequence of Herschel's arguments, and an attentive com-
parison of the two theories. This ether, then, is supposed to exist in
the pores of all bodies, being more dense in solid bodies than in
empty space, but possessing less elasticity. An impulse being given
it, a succession of waves is produced, precisely like sonorous vibrations
which strike upon the retina and cause that membrane to move back-
wards and forwards, or vibrate, as the undulatory motions of the air,

316 Scientific Intelligence. [April

excited by sonorous bodies, occasions motions in the membrana tym-
pani. These vibrations follow in regular succession, and according
as they are more or less frequent or rapid in succession, the sensation
of colour is produced.

The following table exhibits the number of vibrations which are
distinguishable in a second, and the length of a wave :
Number of vibrations, Length of a wave.

32 32

64 16

128 8

4096 3 inches.

8192 ... . li
The number of vibrations which produce the different colours of
the spectrum has been calculated with wonderful precision :
Red . . . 458,000,000,000,000.
Orange . . 506 „

Yellow . . 635
Green . . 577 a

Blue ... 622
Indigo . . 658 „

Violet . . 727
The length of a wave is '0000266 inch, from which we can calcu-
late the vibrations.

These numbers are so enormous that one is apt to be sceptical as
to their accuracy. Their computation is, however, extremely easy,
and we are perfectly certain that they form very close approximations
to the truth.

By screwing two plates of glass together, the rays of light pass
through the first, and are refracted by the second, and when received
on white paper, exhibit the fits of Newton, consisting of alternate
light and dark colours. A happy idea struck Dr. Ritchie on the
morning previous to his lecture, that by a modification of this prin-
ciple, Newton's rings might be exhibited. He accordingly screwed
together two plates of glass, divided at their margins merely by a
layer of gold leaf, directing the pressure upon one central point with
the extremity of the screw, around which were beautifully displayed
the rings as he had anticipated. These may be enlarged by additional
pressure near their circumference. In this way these can be measured,
and the above numbers deduced. Frenelle, by means of ingenious
apparatus, has been enabled to exhibit the length of the waves, and
measure them by means of a microscope. His results were the same
as those given. Dr. Ritchie considers that the experiments of Frenelle
prove conclusively that light consists of the undulations of a fluid,
interfering with each other and producing darkness.

A further proof in favour of the theory is, that when light is passed
through a small aperture, by reflexion, we have, if we place a sheet
of paper opposite to the hole, alternations of red and dark colours,
and M. Arago has shewn that light moves more slowly through glass
than air. M. Colladon, by some very interesting experiments at
the lake of Geneva, has proved that with sound as with light, the
angle of incidence is equal to the angle of reflexion. Newton ob-
jected that if light, like sound, consisted of waves, sound ought to

1835.] Scientific Intelligence. 317

have a shadow. Now, the fact is, that when sound passes very
rapidly we have a kind of shadow of sound. When two tuning
forks are set differently, we have one sound ascending and the other
descending, affordingja strong similarity to the interference of undula-
tions. When light is polarized, as by Iceland spar, if we cause two
portions to act upon the same plane, alternations of dark and light
colours are obtained, shewing interference of waves, but when these
portions act at right angles no such interference takes place. When
light passes through a gas, and when we examine the spectrum, we
observe dark spaces, which may be occasioned by one wave interfering
with another. Light from the sun does not possess polarized pro-
perties which light from a hot iron does, shewing that light is derived
from the sun's atmosphere, and not from the substance of that lumi-
nary, because, in the latter case, there would be a gradual diminution
of its size. A strong argument in favour of the undulatory theory
is derived from a recent experiment of Mr. Faraday, who found, by
the action of electricity, that as much light was given out from a
copper wire in the course of a few days as could be emitted from the
sun in a year. Is it possible to suppose that this enormous quantity
of light existed pent up in a substantial form in the wire ? Dr. Ritchie
gives his decided negative to such an opinion, but is inclined to infer
that the light which enables us to see exists within ourselves, as the
heat which warms us is contained within us.

6th February. — Dr. Faraday exhibited some very beautiful expe-
riments illustrative of his new researches in electricity, an account
of which was read the previous night at the meeting of the Royal
Society. They referred to the phenomena of induction, which con-
stitute the facts from which Dr. Faraday has raised a new branch of
science. He shewed that the electric spark and shock may be obtained
by means of a helix connected with a voltaic pile and a long train of
wire, leading into a bason of mercury, the instant that the current is
broken ; proving that the effect is produced by the agency of the
induced current. The same phenomena do not occur when short
wires are employed. He exhibited likewise the electro-magnetic-
machine, in which the electricity developed in a coil of wire is beau-
tifully elicited by means of a magnet rotating in contact with mer-
cury. This instrument forms an excellent means for procuring an
instantaneous light, as the spark is capable of igniting combustible
bodies, as candles, lamps, &c. We shall take the earliest opportu-
nity of presenting our readers with an analysis of Dr. Faraday's
papers.

13^ February. — Mr. Landseer read a very learned disquisition
on a monument, of which a cast was brought to this country by Mr.
Joseph Benomi, who has recently published travels in the East. The
original of this ancient relic exists along with nine others on the sea
shore near the river Lycus, two hours journey from Bayrroot. With
the exception of this one of which the cast was exhibited to the meet •
ing, by permission of Lord Prudhoe, the monuments are much de-
faced.

They were probably seen by Herodotus, for he describes similar
relics in Ionia. Maundrell saw them in 17^7> and describes them
with great accuracy. Benomi is the only other modern traveller who

318 Scientific Intelligence. [April

has been fortunate enough to fall in with them. He, in the most
praiseworthy manner, undertook the labour of making a cast of the
most perfect one, instead of carrying off the original in the way too
often practised by eastern visitors.

It appears to relate to Sesostris or Rameses II., who lived, according
to Dr. Pritchard, 1007 years from the commencement of the Egyptian
era. The principal feature in it is the figure of a monarch, with a
sceptre in one hand, and a dove in the other, of which, however, only
the tail remains. The dove was the standard of the Assyrians, hence,
in the Bible it is represented as an oppressor. Over the dove are 7
orbs, which are the seven stars the pleiades, the Succoth-penneth,
or tents of the daughters in Scripture, called genial and exhilirating
stars, and are shedding their influence over the dove.

The face of the monarch is towards the east, and the stars are
placed on the east of the monument, rising with Aldebaran. Two
larger orbs represent the sun and moon, supplied with wings similar
to the sculptures of Persepolis. There is still another star which is
probably Venus, the morning star. Mr. Landseer from these and
similar data, concludes that this monument was sculptured in the
time of Pelassar or Salmanassar, twenty-five centuries ago. Another
monument of which a drawing by Benomi was exhibited, contains on
its margin the hieroglyphical name of Sesostris, identical with that
which exists on the table of Abydos. The sculpture represents the
figure of a man holding a bow in his right hand and a battle-axe in
his left, in the act of offering prisoners to a deity. Herodotus des-
cribes an Ionian monument almost identical with this. Another of
the monuments observed near Sidon, relates the circumstance of
Antoninus having altered the road along the coast, the former road
having been at a greater elevation.

In the course of his lecture Mr. Landseer displayed an intimate
acquaintance with sacred and profane history, and shewed that his
mind was keenly alive to the refinements of literature. In some of
the poetic flights in which he frequently indulged, we were brought
back to those ancient times, when the kindly influences of the hea-
venly orbs presided over human destinies, and the descriptions might
have almost induced the sanguine to regret, that such mysterious
days have passed away.

III. — Pharmaceutical Preparations .

1. Antacid Lozenges. — This preparation may be made as fol-
lows : — Take 33 oz. 34 dr. of pounded sugar ; Sesquicarbonate of soda,
1 oz. 7i dr. ; Mucilage of gum-arabic, 5£ oz. Mix the sugar and the
sesquicarbonate in a mortar, add the mucilage, which may be mixed
with a little conserve of roses, oil of peppermint, or orange-flower
water, and form the mass into a paste, which may be divided into
oval lozenges, weighing about 14| grains. Each will contain about
"- of a grain of sesquicarbonate of soda. (Journ. de Chim. Med.

2. Chloride of Zinc. — Professor Hanke* of Breslaw has employed
salt successfully as a caustic in fungus hematodes, malignant pus-
tules, neviae and syphilitic ulcers with a carcinomatous appear-
ance. He prefers it to corrosive sublimate, red precipitate, nitrate

1835. Scientific Intelligence. 319

of silver, or arsenic. The latter he thinks ought never to be used.
M. Canquoin recommends its application in cancerous diseases, in
the form of a paste, consisting of two to four parts of flour, to one of
chloride of zinc, brought to the proper consistence by means of water.

Muhrbeck has employed it with success internally, to the extent
of from - to 1^ gr. for the cure of periodical headache. Hanke has
also used it in chorea tic douloureux, epilepsy, dissolved in muriatic
ether, (1 gr. chloride, 6 scs. ether) beginning with five drops every
four hours. When taken in over-doses it produces nausea, vomiting,
cold sweats, convulsions. It may be prepared by distilling one part
of zinc with four parts of corrosive sublimate, or by evaporating to
dryness a solution of zinc in muriatic acid. These differ in some
respect, for the first, called, butter of zinc, is volatile, while the
other is only so at a red heat. (Journ. de Chim. Med. i. 77«J

3. Mercurial Ointment. — M. Langlois, according to the sug-
gestion of Chevallier, recommends the following process for making
this ointment : He introduced 1| lb. troy into a glass bottle, and
poured upon it 7t oz. of melted fat. He then placed the stopper in
the bottle, and agitated the mixture until it became cold. It was
then placed in warm water, and again liquified. While still soft,
the mixture was poured into a marble mortar previously heated with
warm water in order to retard the cooling. It was then triturated
briskly for three quarters of an hour. No globules could then be
observed. The same quantity of fat was added as at first, and the
whole was triturated for an hour. The preparation of the ointment
was now completed. (Journ. de Chim. Med. i. 125.^

IV. — Muriate of Ammonia in some Minerals.

M. Vogel of Munich has found, 1 . That muriate of ammonia exists
in the oxide of iron from Bohemia, but those oxides which he exa-
mined that were brought from Bavaria, at a distance from volcanoes,
contained none.

2. That the common salt of Frederickshall, in Wirtemberg ; the
rock salt of Hall, in Tyroll, as well as the different salts of all the
countries of Bavaria, contain, like volcanic products, muriate of
ammonia.

3. That the water of saline springs does not appear to contain
sensible traces of muriate of ammonia, (Jounal de Pharm, xx. 501. )

V. — Peroxide of Manganese.

Vogel of Munich has found organic matter in this mineral, as
well as in amphibole, nepheline, asbestus, adhesive state of Menilmon-
tant, felspar, and flexible sandstone of Brazil. He detects the organic
matter by boiling the mineral with distilled water, decanting without
filtering, and exposing the liquid to the sun mixed with a few drops
of nitrate of silver ; if organic matter is present a red wine colour
will be produced. The presence of this matter in the peroxide of
manganese accounts for the carbonic acid which comes over in the
preparation of oxygen. The muriatic acid which is sometimes ob-
served when oxygen is obtained from this mineral by sulphuric acid,
is derived from the latter, as Mr. Kane had shewn. (Journ. de
Pharm. xx. 502 J

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RECORDS

OF

GENERAL SCIENCE

MAY, 1835.

Article I

On Calico-Printing. By Thomas Thomson, M.D., F.R.S.,
L. and E., &c, Regius Professor of Chemistry in the
University of Glasgow.

( continued from p. 173. )

In the paper on Calico-Printing inserted in the third
number of this Journal, I gave an account of the mode
employed, to prevent the fixing of the dye on particular
parts of the cloth, or of discharging it after it has been
fixed. At present, I mean to explain the methods practised
in the application of chemical colours to calicoes.

The term chemical seems originally to have been applied
to certain colours, which were prepared by means of sub-
stances brought directly from the laboratory of the chemist,
as distinguished from those made of materials previously
in common use. They consist principally of solutions of
tin, mixed with decoctions of the various dyewoods ; and,
as the colouring matter of these woods is readily acted
on by the light, as well as by alkalies and acids, chemical
colours came to be understood as necessarily fugitive colours.
Chemical blue also, (a solution of Prussian blue in muriatic
acid, or perchloride of tin,) and various other topical appli-

VOL. I. Y

322

Dr. Thomas Thomson on

[May

cations are of the same class. But the fugitive character
of these colours is to be attributed rather to the unstable
nature of the colouring materials, than to the manner of
their application. Could the colouring matter of madder,
for example, be produced pure and unchanged in a state of
solution, there is little doubt that the chemical which might
be obtained from it would be a permanent colour. A state of
solution more or less complete is necessary to the adhesion
of these chemical colours to cloth.

1. Chemical Black.

This colour is produced in a variety of ways. Some years
ago it was almost universally a decoction of nutgalls, to
which, after it became cold, nitrated peroxide of iron was
added, previously thickened with flour. A paste was thus
produced, of a slate colour, which being printed on the cloth
and afterwards exposed to the air, became black. Now it
is considered better to use a salt of the protoxide of iron,
which, after being printed on the cloth, is exposed to the
air. The iron is gradually peroxidized, and the colour be-
comes black. In a dry atmosphere, several days exposure
to the air are necessary to peroxidize the iron completely.
The black compound is then insoluble in water, and when
the cloth is washed, nothing is removed except the thick-
ening matter, and other superfluous matters which are
not combined with the fibres of the cotton. A chemical
black is also produced by mixing a decoction of logwood
with a protosalt of iron ; but it is not so permanent as the
gall black.

1835.] Calico-Printing. 323

The portion of calico here presented to the reader
exhibits specimens of no fewer than four different chemical
colours : namely, pink, blue, green and orange. I shall
endeavour to explain how these different colours are
obtained.

2. Chemical Pink. — This beautiful colour is produced
either from Brazil or peachwood. A decoction is formed of
these woods, which is thickened with gum-senegal, and
afterwards mixed with perchloride of tin. The salt preci-
pitates the colouring matter in the state of a lake, which is
re-dissolved by an excess of the salt of tin. In this state
of solution it is applied to the cloth, which in the course of
a few hours decomposes it, and when the cloth is washed,
the lake remains attached to it.

3. Steam Blue. — It is known that when hydro-ferro-
cyanic acid is boiled in water, hydro-cyanic acid is evolved,
and a white powder precipitates which becomes Prussian-
blue by exposure to the atmosphere. It is in this way that
what is called steam-blue is produced. Crystallized prussiate
of potash is dissolved in water, and mixed with tartaric acid.
Bitartrate of potash or cream of tartar precipitates, and the
remaining liquid consists partly of hydro-cyanic acid dis-
solved in water ; but it contains also ' the white Prussian-
blue, if such an expression may be permitted. This liquid
is thickened with gum and printed on the cloth.

Or sometimes gum-senegal is dissolved in aqueous prus-
siate of potash, and an equivalent of sulphuric acid added.

The print is now exposed to the steam of boiling water,
and the blue raised* (if the other colours will allow) in a

* The technical term for increasing the intensity of a colour.

y2

324 Dr. Thomas Thomson on [May

weak solution of chloride of lime (bleaching powder,) or of
bichromate of potash. Should such a process be incom-
patible with the other colours, the cloth is merely exposed
to the air for a considerable time, by which the blue be-
comes almost as deep as when chloride of lime is employed.

4. Steam-Green. — This colour is, in fact,v a combination
of the preceding, with a yellow colour, produced by a de-
coction of Persian berries, and fixed on the cloth by alum.
The precipitate of potash is dissolved in water, and this
liquid is mixed with a decoction of Persian berries and
alum. These substances have no sensible action on each
other while cold. But on the application of steam after
printing, the acid of the alum becomes united with the
potash, while the alumina combines with the yellow colour-
ing matter of the Persian berries, and fixes it on the cloth.
At the same time the heat causes the deposition of the white
Prussian-blue, which gradually assumes a blue colour by
exposure to the air. The blue and yellow colours united
are well known to produce a green.

5. Annatto Orange. — Annatto is dissolved in potash or
soda, and printed on the cloth. This constitutes the whole
process.

6. Chrome Yellow upon Turkey- Red.

This is produced by a modification of the patent process
described in a former part of this article. Tartaric acid
and nitrate of lead are dissolved together in water, which
is thickened with gum, and printed on those parts of the
Turkey-red cloth that are to become yellow. When the
cloth is passed through a solution of bleaching powder,

1835.] Calico-Printing. 325

those parts of it on which the tartaric acid had been de-
posited, are deprived of their colour, while at the same time
the oxide of lead detaches itself from its acid and becomes
fixed upon the cloth. The cloth, after being washed in
water, is passed through a solution of bichromate of potash,
which converts the oxide of lead into chromate, and thus
communicates the beautiful and permanent yellow colour.

7. Blue and Black upon Turkey -Red.

The mode of discharging the colour from Turkey-red
cloth has been already explained, and also the mode of
impregnating the white spots thus formed with chrome
yellow. At present we shall endeavour to explain how the
black, the blue, and the green, which add so much to the
beauty of the calico here presented to the reader, are induced.

To obtain the black a perchloride of iron is prepared,
by dissolving carbonate of iron in muriatic acid. This
solution is afterwards employed for dissolving Prussian-
blue, which it does very well, provided the blue be ground
into a fine powder. The solution is afterwards diluted with
water, and brought to the proper consistency by mixing it
up with starch, and keeping it for some time at the tempera-
ture of 200°. The paste thus made, when cooled down is
fit for use. It is applied to or printed on the cloth at the
same time with the blue, and with the acid which is to pro-
duce the white observable on a portion of the cloth. The
cloth being passed through a solution of chloride of lime,
the free lime precipitates oxide of iron upon the Prussian-
blue, which assumes a black colour, because it has been
superinduced upon the red.

326 Dr. Thomas Thomson on [May

The Prussian-blue, to induce the blue colour so conspicu-
ous in the calico, is dissolved in perchloride of tin, which is
prepared by passing a current of chlorine gas through a
solution of protochloride of tin. The solution is then
diluted with water, in which tartaric acid is dissolved, in
the proportion of 4 lbs. to the gallon, and afterwards
thickened with starch or British gum. It is then ready for
use. When cloth on which this paste has been printed is
passed through the vat containing a solution of chloride of
lime, the oxide of tin is precipitated by the action of the
free lime upon the perchloride, and fixes the blue on the
cloth ; while, at the same time, the tartaric acid, by dis-
engaging chlorine from the chloride of lime, destroys the
red colour of the cloth. Hence, the blue shows, as blue
always does when deposited on a white ground.

The yellow portions of the calico had been rendered white
in the way formerly described. The yellow was afterwards
induced by a decoction of Persian berries. When this
yellow die was deposited over the blue it formed the green
so conspicuous in the calico, and adding so much to its
beauty.

8. Chrome Yellow on Indigo Blue.

The mode of obtaining a white upon dark-blue has been
already described. To form a paste which shall at the same
time resist the blue vat and leave a mordant for yellow, a
solution of nitrate and acetate of lead, with nitrate and
acetate of copper, is formed and brought to the requisite
consistence with gum and pipeclay. While the indigo is
depositing itself upon the cloth, the lime which holds it in

1835.]

Calico- Printing.

327

solution is precipitating the oxide of lead on those parts of
the cloth to which the paste had been applied. After being
washed in water, the cloth is passed through a solution of
bichromate of potash. Those parts only become yellow
upon which the oxide of lead has been fixed. But the
colour is at first pale and dirty, from the presence of a
quantity of oxide of copper deposited at the same time with
the oxide of lead. To remove the copper and heighten the
yellow, the cloth is immersed in a weak solution of muriatic
acid in water.

9. Orange and Yellow upon Blue.

The process in this case is the same as in the last, only
the cloth, instead of being passed through a hot solution
of bichromate of potash, is passed through dichromate of
potash. Two atoms of oxide of lead combine with one
atom of chromic acid and thus produce the orange. When
weak nitric acid thickened with gum is printed upon
portions of this orange, half of the oxide of lead is removed,
and the orange is immediately converted into yellow.

10. Chrome Yellow upon Bronze.

* /v.

328 Dr. Thomas Thomson on [May

Sulphate of lead is mixed with chloride of tin, and printed
upon bronzed cloth. A double decomposition takes place,
and chloride of manganese with peroxide of tin is formed.
When the cloth is washed in water the chloride of manganese
dissolves and is carried away, but the tin remains adhering
to the cloth, and along with it the sulphate of lead. This
salt is afterwards decomposed by lime, and the oxide of lead
adheres to the cloth, and becomes yellow when the cloth
passes through a solution of bichromate of potash.

Instead of sulphate of lead, other substances may be
deposited in a similar manner. The pale chromate of lead,
for example, may be mixed with protochloride of tin, and
remain so for some hours without material injury. A yel-
low is thus produced without the necessity of any subsequent
operation. The lake from Brazil wood or cochineal may
also be employed to produce a pink discharge upon bronze,
that of logwood a purple, &c. But prints formed in this
way cannot be washed, even in cold water, with any degree
of freedom.

Red oxide of iron is permanently fixed upon bronzed
cloth, as may be seen in the specimen of cloth marked
No. 9, by printing a solution of protochloride of iron on the
parts of the cloth that are to undergo the alteration. In a
few hours the manganese and iron change places, the iron
being deposited on the cloth in the state of peroxide, while
the chloride of manganese is removed by washing.

11. Red and Chocolate Resist on Pale Blue.

If the aluminous mordant, with the addition of a little
verdigris and soft soap, and thickened with gum and pipe-

1835.]

Calico-Printing .

329

clay, be printed upon white cloth, the piece may be im-
mersed in the blue vat without any of the indigo attach-
ing itself to the parts of the cloth so printed. If the
piece of cloth be then dunged and dyed in the usual way,
a red is produced on a pale blue ground. The same mor-
dant, with the addition of acetate of iron, gives a chocolate
colour.

Let us now explain how the white portion in the speci-
men of printed cloth before us has been preserved from
the dye. A preparation called neutral paste is employed in
this style of work, to defend the cloth against both the
red and chocolate and the blue. It is a mixture of lime-
juice and sulphate of copper. If this mixture remains
upon the cloth longer than a few days, a portion of the
oxide of copper attaches itself so firmly to the cloth that
no washing is capable of removing it. And this portion
of copper attracts a portion of the madder in dyeing, and
tinges the part of the cloth intended to be white, of a pale
brownish red.

In the specimen before us, all that is now bronze, yellow
and pink, was originally printed with the white ; the three
colours given by catechu, Persian berries, and Brazil pink,
being a subsequent application. The green is the result of
berry-yellow on the blue, and the orange of the same colour
on the pink.

12. Pigment Printing,

This is a species of printing which has been lately in-
troduced for dresses which are not intended to be washed.
The colours are the same that are used for painting or

330 Dr. R. D. Thomson on the [May

printing on paper; and being body colours, which conceal
what is beneath them, they are used for black and various
other coloured grounds. A brilliant effect is thus produced
at small expense.

Article II.

Sketch of the Geology of the Bombay Islands. By

Robert D. Thomson, M. D.

( Continued from p. 304. )

ELEPHANTA ISLAND.

The form which this island presents at a distance is some-
what pyramidal, but on a nearer approach it is found to
consist of two distinct hills, with an intervening valley.
This vale is profusely studded with trees and bushes, as
well as the hills, which are clothed with wood from the
water's edge to the summits. Many of the trees are tall
and stately, as the brab or palmyra, while others are covered
with the densest foliage, as the tamarind, with its rich
green leaves and elegant blossoms. In the dry season the
island exhibits the best appearance from the summits of the
hills, or by approaching it from the sea, for at that time the
earth is dry, parched, and as if baked, being crossed in every
direction with fissures, which greedily suck up tbe rain
whenever it happens to fall, and, of course, is destitute of
that rich vegetable carpet which covers it during the pre-
valence of the monsoon. Then the soil is one mass of
verdure ; not a spot is naked ; the paddy ground being
enlivened with the presence of the rice crop, and the forest
waste adorned with grasses and elegant flowers. The rice
ground is very limited, and is situated at the lower part of
the vale, in the immediate vicinity of the village of Galli-
pooti. It is divided into parterres, or small inclosures,
fenced with impervious hedges of pricklypear (Euphorbia
neriifolia and terucalli.) The whole island is one mass of
rock, and the thin scattering of soil which hides but scan-
tily the main constituent of the island, is merely derived
from the disintegration of the latter. At the southern
landing place there is a ledge of large masses of amygdaloid,
(of which the cavities have been washed empty, if we except

1835.] Geology of the Bombay Islands. 331

a few nodules of quartz) over which the surf beats high and
renders landing dangerous, although it forms one of the
few situations in these islands, where boats can reach the
shore without grounding.

Near this landing place is a Portuguese ruin, situated on
a knoll, and adjoining it, we discover the extraordinary
artificial figure from which the island derives its European
name, for its Hindoostani name is Gallipooti. The animal
represented by this sculpture is evidently an elephant, fully
equal to the natural size, and, upon the whole, well executed.
The trunk and head have been separated from the body,
and lie fractured and prostrate on the ground. Considerable
damage has been done to other parts of the figure, for the
instrument of which we must have recourse to the tradition
current in that neighbourhood, which states that the Portu-
guese went so deliberately to work as to employ cannon in
effecting their barbarous work of destruction, from the idea,
as we have shewn, of extirpating superstition ! The rock of
which the figure consists is a very hard basalt, (No. 2.)
containing a few minute cavities, scantily supplied with
mineral crystals, and is of the same nature as the rock of
the adjoining hillock. From this spot the ascent of the
western hill is pretty easy, the pathway leading along the
bed of what constitutes a torrent during the wet season,
formed in the porphyry and amygdaloid, and runs to a
considerable depth ; a kind of natural walls rising up on
each side, which are overshadowed by carissa bushes
(Carissa carandas,) agnus castus # ( Vitex trifolia,) the
garruga tree (Garruga pinna ta,) with its abundant fruit
hanging in clusters, like the produce of the vine and castor
oil tree (Ricinus communis,) while the soil is ornamented
with the solanum (Solanum Jacquini,) and the Mexican
Argemone f (Argemone Mexicana.) About half way up

* The leaves of this shruh are employed by the Hindoo women in some religious
ceremony, as I found a quantity deposited on the convex stone in the lateral
square compartment of the great temple.

t The occurrence of this plant, (a native of the New World,) wherever the
Portuguese have formed settlements, is a striking instance of the agency of man
in the distribution of vegetable species. In addition to the habitat here given, I
have observed it at Malabar Point in Bombay Island ; on the Island of Coulaba;
and at the south end of the town of Macao, in China, in all of which localities it is
an abundant plant, affording a parallel case with that of the Chenopodium ambro-
sioides, (cited by Lyell, vol. ii. p. 83.) which we observe so abundantly in the
Island of St. Helena.

332 Dr. R. I). Thomson on the [May

the hill the smaller temple or caves are reached. They are
three in number, having the face of the rock polished
perpendicularly, and some pillars formed on its surface,
with several figures represented flying in the clouds. The
inferior part of the rock consists of a variegated porphyry,
sometimes reddish, and frequently of a yellow tint, the basis
consisting of clay, and the inclosed particles of altered
quartzoze grains, &c. (No. 4.)

Remains of painting are still observable, which seems to
have originally been of a red colour, but has in some places
faded to a purple hue. The upper part of the rock, com-
mencing at the roof of the apartments, is composed of
amygdaloid, having a wacke basis, and containing cavities
filled with rock-crystal, calcareous spar, zeolites, and many
other minerals which a careful examination would readily
detect. During the rains these caves are filled with water.
The whole face of -the hill above these caves is craggy, con-
sisting of amygdaloid, porphyry occasionally appearing, and
is covered with thick jungle, and climbers ascending the
stems of the numerous trees. Among the former we chiefly
remark the Dalbergia scandens, and among the latter, the
Getonia floribunda, with its bunches of flowers.

The path, continuing to wind up the declivity, conducts,
after passing a fine specimen of the tamarind tree, and of
the Asclepias gigantea to the great temple which faces the
north. Like the lower antiquities, it is an excavation in
the solid rock, with, however, a much greater extension of
human art, for the space included within the walls of the
large apartment is a square of 43 yards, # and 18 feet in
height, supported by three rows of pillars, consisting of
rounded fluted capitals and square shafts. The walls are
covered with gigantic figures, all of which have beenmutu-
lated, with the exception of the colossal representation of
the Trimurti fronting the entrance, and one entire masculine
form in the recess to the right. The rock is amygdaloid,
occasionally assuming a purely porphyritic appearance. The
effects of the atmosphere upon the more exposed portions
of the rock are obvious, for it is evidently decaying and
crumbling to powder, and, combined with the ravages pro-
duced by visitors, would, in the lapse of time, prevent the

* This number is derived from the resident sergeant. I made it forty-six
paces.

1 835.] Geology of the Bombay Islands. 333

probability of any remnant continuing, had not the fore-
sight of the honourable governors of the country obviated
the latter cause in some measure, by stationing a resident
sergeant to guard these interesting relics. The rock, when
first exposed, is highly indurated, and difficult either to
fracture or polish, both of which circumstances add greatly
to the wonder and admiration with which we must view the
temple and sculptures.

In geological investigations, not the least interesting
inquiry consists in observations with regard to the degra-
dation of the rocky masses, and the formation of the soils
for the growth of the members of the vegetable kingdom.
Such questions, it is obvious, can be most satisfactorily
solved on insulated lands, where no agencies save the pure
natural causes can come into operation. Coral islands,
which are of such recent formation, present the most simple
illustration upon this point, where we find the calcareous
masses splitting under the action of the sun's rays, crum-
bling and affording a scanty soil for foreign seeds floated
by currents to take root, and thus to extend the formation
of the soil, by the loosening power of their roots and the fall
of their leaves.*

The heat of the sun alone may be considered, therefore,
a powerful auxiliary in the production of soils, and this
influence is especially applicable to the Indian climate, where
the dark hue of the rocks greatly favours the imbibition
of heat ; an observation similar to that which was made by
Link, with regard to the black slates of Pezo,f and subse-
quently by Humboldt, was demonstrated in reference to the
black bare rocks on the banks of the Oroonoko, whose
temperatures were found to be elevated during the day
34|° F., and during the night 18° above that of the atmos-
phere .% In India, at the termination of the rains in Sep-
tember, the porous stony masses must of course be satu-
rated with moisture, and when the rays of the sun excite

* Dr.R. Forster has well described the structure and mode of formation of coral
islands, in Cook's Voyage, of whose accuracy the present writer had ample proofs,
while examining similar deposits on the coast of Sumatra. A fuller, but not more
distinct account of coral islands is detailed in Beechy's Voyage.

t Link's Travels in Portugal, 8vo. 1801, p. 64.

% Humboldt's Pers. Nar. vol. v. pt. i. 26.

334 Br, R. £>. Thomson on the [May

their influence, and are imbibed, the water must necessarily
be vaporized, and disintegration of the rocky masses ensue.
This effect of vapour must be considered as a powerful
agent, although not so explosibly effective as the freezing
of water :

cum tristis hyema etiamnum frigore saxa

Rumperet."*

Because, in one case the confined body has some means
of egress, though far from free, while, in the other, the
barriers must yield on every side to the overwhelming mass
within. When the soil is carefully examined, all the ap-
pearances confirm the idea of its derivation from the rocky
mass. It has a black colour, which it may in some measure
derive from particles of oxide of iron, which are occasionally
observable in the porphyry where it has begun to decom-
pose, and from the vegetable matter derived from the trees.
No considerable portions of iron have been detected in this
neighbourhood, although the oxide of that metal is found
in considerable abundance among the Ghauts, and is smelted
with some profit at the Mahabuleshwar hills. f In conse-
quence of the mixture of vegetable matter with this light
rocky production, the soil has been rendered fit for raising
some scanty crops, which serve to support the inhabitants
of the island, who amount to about a hundred. It is a
curious fact in the history of this island, that no water can
be obtained by sinking wells near the beach, and that the
sole supply of the inhabitants is procured at the summit of
the hill, where a cool spring exists in a dark cave near the
great temple, affording a plentiful supply, from which it is
conveyed by the Hindoos to their habitations in porous
earthen vessels.

CARANJA ISLAND.

This is a large island, situated the most southerly of any
in the harbour. It consists of two hills, with an intervening-
valley. The best landing place is situated on the north-
east side of the island, at a fishing village, where, however,
the water is very shallow, and where it is necessary, in
order to effect a landing, to employ a native canoe. The

* Virg. G. iv. 135.

t " Account of the convalescent station of Malcolm Paiton the Mahabuleshwar
hills," Bombay, 1830, pamphlet. The chemical nature of the ore is not stated in
this publication, but it is probably the magnetic iron ore.

1835.] Geology of the Bombay Islands. 335

shore here is bounded by rocks, as at Elephanta, of the
amygdaloidal species. The shingle consists of bivalve
shells (Area granosa) and waterworn porphyritic gravel.
The ascent of the lesser Caranja hill is gradual and easy
from the village to the summit of the ridge. The rocks
have an inclination to the east and west, as if shelving
down on each side of the ridge, presenting the appearance
of stratification, or successive deposition, and are covered
with low jungle of carissa, ixora, euphorbia, and lawsonia.
The descent on the west leads to paddy ground, where there
is another village, surrounded with neat gardens, and sup-
plied with a tank, fifteen or twenty feet in depth, dug out of
the solid rock, with a wheel and earthen pots to raise the
water, as is usual in the east. In this valley there is a fine
specimen of the Adansonia digitata, sporting a colossal
trunk, and spreading out its branches to overshadow the
circumjacent cultivated ground. # To reach the top of the
ridge it is necessary to cross several mountain streams,
whose beds are dry except during the rainy season. The
rocks are all amygdaloid, on the western as on the eastern
declivity, filled with zeolites, &c. and are well exposed in
the streamlets, sometimes rising in the form of round
masses, at other times shelving out and affording a level
run for the water, and then terminating in a small per-
pendicular fall at the edge of the rock.

On the eastern side, in this manner, a very picturesque
waterfall is formed, the height of the vertical face of the
rock being at least twenty feet, over which the whole
water of the torrent is precipitated in one sheet, presenting
altogether with the rich foliage of the tamarind in the
foreground, a pretty scene. Near this a specimen of meso-
lite was obtained, among innumerable minerals, which may
be observed scattered about on the surface of the island,
very frequently covered with a blue coating, produced by
the presence of iron. Besides mesolite I observed calce-
dony, agates, rock-crystal, calcareous spar, and heulandite.

The south-east point of the small hill consists of craggy
rocks of porphyry, affording, in their numerous recesses,

* In this valley I found a specimen of the Agaricus campestris, the identical
English ketchup mushroom, of the existence of which plant, in this part of India,
at such a slight elevation above the sea, I have never previously heard.

336 Dr. R. B. Thomson on the [May

abundance of hiding places for lizards and serpents, especi-
ally the Cobra de Capello, which is extremely frequent in
these islands. The clefts also afford good habitats for the
fern Gymnogramma chylomelanos, and the Asparagus
sarmentosus.

The large Caranja hill is similar in its conformation to
the smaller hill, and is crowned by the ruins of an old fort,
which was a place of considerable note, when Europeans
first settled on this coast.

At low water the island is connected with the continent,
the intervening valley being quite green, and studded with
a few pools of water. The vale which separates the two
hills, and divides the island into two parts, is covered with
palm trees, amid which are situated cottages and rich gar-
dens, at a small elevation above the level of the sea.

GENERAL OBSERVATIONS.

In the course of the preceding remarks it appears that,
on the continent and along the coasts of the different islands,
the soundings do not deepen suddenly, but that the water
at the shore is shallow, and that it gradually increases in
depth in proportion as we recede from the land. The same
remark applies to the whole coast, from the Persian Gulf
to Cape Comorin, and, it is on a careful attention to the
depth of water and the nature of the bottom, that navigators
in stormy weather must depend. In the latitude of Bombay
this remarkable sub-marine portion of land which can thus
be reached with the lead, attains an additional degree of
breadth, jutting out to a greater extent into the Arabian
sea, and, from its occupying such a considerable space, and
affording good fishing ground, although it can only be con-
sidered as an expansion of the shoal water along the coast,
it has been termed the Bank of Soundings. The deposit
generally obtained in the bottom of the harbour, and on
this bank near the coast, consists of a blue clay of a stiff
nature, and is, therefore, serviceable by affording good
holding ground for anchors. A section, representing the
relative situations of the sea and the Bank of Soundings,
will explain the subject more clearly than can be expressed
by detailed descriptions. The horizontal line represents the
sea level, and the inclined one the bottom of the ocean,

835.] • Geology of the Bombay Islands. 837

55 50 U7Sea

45 40 in

/

X

.y^1

/

~-J"^~'

which is here shewn to be a gradual descent from the sum-
mit of the high land. By sounding regularly we discover
our distance from the coast, as appears from the following
table :—

10 miles from the coast the soundings are 14 fathoms ;
bottom, mud.

40 do. 40 fms., sand, gravel, and shells of various colours.

50 do. 45 do. do.
160 do. 50 do. do.
170 do. 55 do. do.

We observe, therefore, that soundings extend as far to the
westward of Bombay as 2° 50', and that, until the bottom
of the ocean begins to ascend, in order to come to the day;
the bed consists of sand, mixed with shells, and that then
it is formed of mud. An observation with respect to the
nature of the shells would be of considerable importance,
because it might enable us to decide, whether they are
natives of deep water, or belong to the shallower parts of
the ocean.

Two explanations occur, to account for the appearances
here described, either, 1st. That the land and ocean have
retained their positions relative to each other since the
formation of the first, the production of the bank being-
similar to the clay deposit round the shore of the island
which so lately appeared, and sunk in the Mediterranean ;
or 2d., That the harbour of Bombay was formerly a valley,
and that the Bank of Soundings was at one time dry ground,
both of which have been submersed by the gradual en-
croachment of the sea. The most undoubted evidence
exists to shew us that this coast has been, even within the
range of a few centuries, subjected to violent convulsions
from earthquakes

vol. i. z

338 Dr. R. D. Thomson on the

In May 1618, six years after the settlement of the Eng-
lish at Surat, " a general and diabolical storm" occurred in
the neighbourhood of Bombay (Bombaim as it is termed
by old writers). It began at Bagaim (Basseen,) on the
15th of that month, and continued with such violence that
the people hid themselves in cellars, in continual dread lest
their dwellings should be levelled with the earth ; and at
2 a.m. an earthquake destroyed many houses. The sea,
according to the historian of the time, was brought into
the city by the wind ; the waves roared fearfully ; the tops
of the churches were blown off, and immense stones were
impelled to vast distances; two thousand persons were
killed ; the fish died in the ponds ; and most of the churches,
as the tempest advanced, were utterly destroyed. Many
vessels were lost in the port. At Bombay, sixty sail of
vessels, with their cargoes and some of their crews,
foundered.

At Aga§aim, a boat was blown by the force of the wind
from the sea into a house, where it killed a woman and her
child, and the trees were torn up by their roots.

Besides the presence of a violent commotion in the
atmosphere, and the powerful concussion of the earth,
volcanic action seems to have occurred, if we may be allowed
to deduce such an inference, from the highly embellished
representations of the historian, of giants seen in the air
throwing great globes of fire at each other, confusions of
human voices in the atmosphere, tramplings of horses, and
the sound of warlike instruments. It is added that much
of this nature occurred in " Salsete," and other places.*

The metaphorical figures expressed in the latter part of
the description, are strikingly similar to those employed by
Dion Cassiusf in his account of the eruption which de-
stroyed Herculaneum and Pompeii, where we are told that
giants were seen, and the sounds of trumpets were heard in
the vicinity.

Frequent mention of earthquakes may be found in the
history of the Malabar coast, (which extends from Cananore
to Cochin, about 42 leagues,) where they go under the de-
nomination of Bhumiculacam. In 1784, a strong concussion

* Sousa's " Portugues Asia," torn. iii.
t Hist. Rom. lib. 66.

1835.] Geology of the Bombay Islands. 339

was felt, and in the province of Nagaracotta, as well as on
the bank of the river Sarayuva, volcanic appearances are
evident. But the most remarkable changes are to be found
in the vicinity of Cochin. On its north side we find the
Island Vaypi, which was thrown up by the sea about the
year 1341. The soil upon this new formation resembles
that of the flat districts of Malabar, which consists of sea
sand and calcareous matter, combined with clay said to be
washed down from the Ghauts. The production of Vaypi
gave rise to a new era, termed Puduvepa (new introduction.)
In the same neighbourhood, Bartolomeo informs us, that he
was witness to the formation of an island, a mile in length,
in the course of ten years, before the church at Celtiyatti,
by the opposite effects of river and sea water, which may be
explained in the following; manner : During the months of
August and September, if the rains have been abundant,
the waters of the river clear away from its mouth, those
sandbanks which have been formed during the height of the
monsoon, in June and July, by the high sea which then
rages in a boisterous manner ; but if the rains have been
scanty, and the force of the river is not sufficient to carry
away the obstruction to its junction with the waters of the
ocean, an inundation of the adjacent country ensues ; the
inhabitants are driven from their dwellings, and so frequent
is this occurrence, that we are told grandchildren can
scarcely point out, with any certainty, the spot where their
grandfather resided, in consequence of the change in its
appearance.

Contemporaneous with the appearance of the Island of
Vaypi, the waters which during the rainy season are dis-
charged from the Ghauts, broke through the banks of the
river Cocci, and overwhelmed a village of the same name
with such impetuosity as to sweep it away, and formed in
that district a river, a lake, and a harbour so spacious, that
very large ships can now lie in security on the north-east
side of Cochin, where the river runs into the sea.*

According to the Hindoo records, the ocean has made
great inroads upon the opposite shore of India ; for, it ap-
pears, from the researches of D. Duante de Meneses, Por-

* Viaggio alle Indie Orientali da F. P. da S. Bartolomeo, Roma, 1796, 8vo.
English translation from tlie German of Dr. R. Forster, 8vo. 1800.

z2

340 Dr. R. D. Thomson on the [May

tuguese governor of India in 1522, among the native writ-
ings, that " Miliapore," seven leagues from " Paleacate,"
the ruins of which were then on the sea shore, was sur-
rounded, according to tradition, 1500 years previous to that
date, by 3,300 stately churches, and that the site of that
most ancient city was distant twelve leagues from the sea.
We are also informed that " St. Thomas dragged out of the
sea an immense mass of timber, which all the force of ele-
phants and art of men could not move."*

In the figure which we have given, it is evident that the
inclined plain at the land has been comparatively but re-
cently submersed, while the horizontal bed has been for a
longer period subjected to the action of the sea, as is evinced
by the layer of sand and shells. The whole of this hori-
zontal portion, likewise, we may decidedly conclude, was
inundated at the same period, for, after the sea had been
raised to the level of forty-five fathoms from the present
surface of the ocean, we can see no impediment to its laying
the whole plain, extending for at least a hundred miles of
longitude, completely under water.

The Hindoos, on the Malabar coast, have a tradition that
the sea extended to the foot of the Ghauts. There does
not appear, however, evidence tending in any degree to
prove that such an occurrence has been of recent date ; but
we are rather disposed to consider the native account, as an
indistinct remnant of the almost universal tradition of a
deluge during the human era.

The agencies of torrents appear of too trival a nature, to
afford a sufficient source of such an extensive submarine
formation, as that which we observe along the Concan and
Malabar coasts, although there can be no hesitation in
admitting that where considerable rivers do exist, the
debris collected by the force of their currents must prove a
serious obstacle to the encroachments of the ocean. But
at Bombay, where the bank is much broader than in
other parts of the coast, no remarkable accumulations occur
at the mouths of the rivers Pan well and Pen, whose
size, indeed, is sufficient to render such an occurrence ex-
tremely improbable, even if actual examination did not
demonstrate the fact to be as we have stated ; and the

* Sousa's " Portugues Asia," torn. i. 270.

1835.] Geology of the Bombay Islands. 341

extensive portion of land in Salsette, which is dry at low
water, is situated beyond the influence of any current save
that of the tide, which it must be admitted, however, is
extremely powerful.

' There seems no reason, then, for supposing that this bank
has been formed by matter forced down by the agency of
running water from the Ghauts, as some have concluded,
because, it exists where there are no rivers to produce accu-
mulations, and it is broadest at the mouths of the smallest
rivers.

. In bringing forward proofs of extensive changes and
violent convulsions, we have endeavoured to exclude
theoretical considerations, and probability is only implied
when we observe that the different islands in the bay may
have been the continuation of the high land in Salsette
and Tull, whose communications have been submersed, and
whose bases are now washed by the overwhelming waters
of the ocean.

Article III.

Geology of JEstramadura, and the North of Andalusia. By
M. F. Le Play. ( Ann. des Mines, vi. 297. 477J

The portion of country described in this paper is included
between the Rivers Tagus and Guadalquiver, on the north
and south, and between La Mancha and Portugal on the
west and east. Interesting as this district is, both in a phy-
sical and moral point of view, it is strange how little infor-
mation we have respecting it. The cities of Seville, Cordova,
and Badajoz, are the only names belonging to it which are
known to the rest of Europe, while Truxillo, Merida, and
Medellin are merely noticed as military stations during the
Peninsular war. Estramadura, and the Sierra. Morena,
which border it on the south, form an inland country, at a
distance from high ways, and remarkable for its vast pasture
lands, which serve to support large flocks of Merino sheep.
Onaccount of the paucity of the population, no travellers have
examined its Geology, for, the only allusion, in a scientific
point of view, to this portion of Spain, which M. Le Play
could discover, was in the small work of G. Bowles, which
was translated into French in 1776. The maps of this dis-

342 M. F. Le Play on the Geology of [May

trict, as might hence be expected, are very imperfect. M.
Le Play states that by far the most accurate is that of Bory
de Saint Vincent. The author has, however, constructed a
geological map, which, as far as his observations extended,
may be considered as correct, and as a most valuable con-
tribution to Science.

The central portion of Estramadura, about Talarrubias,
consists of a plain, which is elevated about 550 metres
(1804 feet) above the level of the sea. The town of Puebla
d'Alcocer, lies 50 metres above this plain, or 602 metres
(1975 feet) above the sea, which is almost exactly the alti-
tude of Madrid, and of the plain of New Castile, which
insensibly sinks towards the south-west, as it approaches
Estramadura. M. Le Play considers this plain as bear-
ing a striking resemblance to that of the Western Hartz,
not only in its corresponding elevation, but likewise in its
geological structure, vegetation and climate.

It preserves an agreeable surface, being distinguished by
ancient, inclined, and occasionally crystalline rocks, and
traversed by a few rivers, whose channels are about 160 or
170 feet deep, and of whose existence the traveller is not
aware till he approaches the ravine in which they run.
Even the largest of these, the Guadalquiver, is fordable in
June, above Seville, and the Guadiana is seldom in a state
to prevent its being crossed in the same manner.

The valley of the Guadiana is depressed 190 feet below
the level of the transition plain. The alluvia of its banks
rarely extend above 200 feet from either bank, and fre-
quently one of its banks consists of a vertical wall of schist
or greywacke. As the river leaves the Sierra d'Alcocer,
however, its escarpments disappear, and plains extend on
both sides. The valley of the Tagus is also deep, and where
it enters Estramadura, this river appears to force its way
with difficulty through a mountainous district. Very dif-
ferent, however, is the character of the Guadalquiver,
which traverses the plain of Andalusia, whose elevation
little exceeds the level of the sea. The plain, which extends
on the left between Cardova and Seville, is not raised more
than fifty feet above the bed of the river.

The ridge of the Sierra Morena follows the direction of
the Guadalquiver, from Cordova to Seville, which is a west

1835.] Estramadura and the North of Andalusia. 343

south-west course, but to the north, the limit, although not
so definite, maybe said to be included between Llerena and
Guadalcanal. In fact, the inhabitants of Estramadura, and
of Andalusia, differ in their definition of this ridge, because,
the mountains being about 1600 metres (5249 feet) above
the level of the sea, the former, in order to reach their
summit, have a less ascent, by above 500 metres, (or 1700
feet) than the latter. This chain appears to be formed of
several groups, which may have been at first separated,
but have been joined by some convulsion. The Sierra de
Guadalupe give a mountainous character to the country,
between the Tagus and Guadalquiver, and consist princi-
pally of granite, according to the reports of the muleteers.
The Sierra de Solana lie to the west of this ridge, and are
distinguished by their stratified graywacke formation.

The country extending between the Tagus and Guadiana
is characterized by numerous broken ridges, some of which
rise 1700 feet, and consist of granite. The depressions which
connect them are termed Puertos. Between the Guadiana
and the Sierra Morena, we find numerous ridges, under the
name of Sierra de Hornachos, running from south-east to
north-west ; Sierra de San Servan, running north and
west ; Sierra d'Alcocer, 350 metres above the plain, con-
sisting of quartzoze rocks, extending west and north ;
Sierra de Cabeza towards west and north. To the south
of these chains is situated the country of Almaden, which
is formed of four rectilinear ridges of hills, the highest of
which is 400 metres (1312 feet) high, and consisting of
quartzite. This district presents to the eye a very barren
aspect, and the traveller cannot understand why such a
considerable population should be attracted thither, until
he learns that rich veins of cinnabar exist in the barren
rocks. To the south of Almaden, between the Rio Alcudia
and Guadalmez, another ridge exists, elevated 450 metres
above the former river, in whose vallies immense masses of
quartzoze sandstone are observed. The western portion of
Estramadura, comprised between the Tagus and Sierra
Morena, is varied with numerous chains of subordinary
hills, attaining a height sometimes of 400 metres (1312 feet)
possessing a rounded outline, and entirely destitute of
arborescent vegetation. These chains are frequently inter-
rupted by parabolic hills with a vertical axis, which have

344 M. F. Le Play on the Geology of [May

generally been taken advantage of by invaders, for military
stations.

Estramadura, therefore, may be described as an elevated
plain, 550 metres (1804 feet) above the level of the sea, and
500 (1640 feet) above the plain which borders the Guadal-
quiver, through which the Guadiana runs, at an equal dis-
tance from the Guadalquiver and Tagus, in a direction a
little to the south of west, while the Sierra Morena, which
traverses the south of the district, triples, in many places,
the difference between the banks of the Guadalquiver, and
the numerous partly isolated chains afford variety to a
country which is always of a rude character. The different
formations met with in this district may be considered in
the following order, beginning with the most ancient
rock : —

1. Granite constitutes a very considerable portion of
Estramadura. Between Garlitos and Almaden, an isolated
tract of this formation occurs, extending from north-east
to south-west- The rock is composed of white felspar,
reddish-brown mica, and small portions of quartz, in minute
quantities, and possesses often a foliated structure. The
most important mass of granite, to the south of the Gua-
diana, is that which lies on the north border of the Sierra
Morena, extends from the east of Puerto Blanco to the
west of Benalcezar, and is surrounded by hills of schist.
The soil is derived from the disintegration of the granite.
To the north-west of this basin, a considerable extent of
granite is met with, the limits of which are marked by
Castuera, Campanario, Quintana, Zalamea, Malpartida,
and Bengareucea. On its eastern boundary the formation
is covered with granitic sand, and the rock possesses an
olive-green colour, derived from the mica.

In the middle of the formation, near the ancient mine of
El-Chantre, which has been long abandoned, the felspar
has, in decomposing, assumed a grayish appearance, and
the rock is covered with rusty stains, produced by the action
of the weather upon the mica. About Quintana the granite
consists of small grains, the hyaline quartz and felspar
forming a beautiful white basis, through which mica is
plentifully distributed. Here also occur large tabular
masses of granite, sometimes 100 feet in diameter, which
have become polished by the atmospheric influences. At

1835.] Estramadur a and the North of Andalusia. 345

Zalamea, a species of black porphyry appears, consisting of
a basis of amphibole and felspar, through which felspar
is disseminated ; M. Le Play calls it Melaphyre. Although
granite appears so frequently among the transition rocks
on the table land of Estramadura, it is seldom met with
among the rocks of the same formation in the Sierra
Morena, afid when it does occur among these mountains,
it is generally in a deep bed of a rivulet, as at Villaharta,
in the channel of the Rio Cuzna. Here the greywacke and
schist appear to be impregnated with the debris of the
granite. On the south of Pedroso, granite, to a small
extent, occurs, which, in decomposing, has given origin to
a thick layer of sand overlying it.

On the north of the Guadiana, the rock appears at
Albuquerque, containing very large felspar crystals, which,
in decomposing, become gray, and give the rock an appear-
ance like trachyte. The quartz is reddish. The town pre-
sents a remarkable appearance, in consequence of the houses
being built among immense masses of rock, which has pro-
duced the most tortuous streets imaginable. At Malpartide
another tract appears, where, from the nature of the soil,
large reservoirs of water have been formed for washing the
wool, which forms the staple product of the industry of this
country. The hills in this neighbourhood are covered with
rounded blocks of granite, lying over the granite soil, and
appearing to have no connexion with the subjacent rocks.
Hence, the inhabitants consider these the work of human
industry. M. Le Play explains their origin very satisfac-
torily, by considering these masses to have been connected
by narrow necks to the subjacent rocks, and that this bond
of union gradually decomposed, and left the main portion
of the blocks above the disintegrated matter. The Sierra
de Montaches, consists of granite, but the effect of external
causes in decomposing it are not nearly so apparent as at
Malpartida. A long band of granite extends from the
Tagus, by Truxillo, south easterly to Torjta, at no great
distance from the Guadiana. Detached blocks are observed
distributed as at Malpartida, upon the hills, the origin of
which admits of a similar explanation.

Euphotide and diorlte. — These consist of compact felspar,
containing a great quantity of crystals, or lamellar pieces

346 M. F. Le Play on the Geology of [May

of diallage, which possesses generally a green or greenish-
brown colour. They are very hard, and are not easily
decomposed. Near Almaden, in the bottom of a valley, a
great quantity of blocks of euphotide exist, which are
employed for fencing in the road to Madrid. It is com-
pact, and admits of a fine polish, the diallage frequently
approaching the appearance of actinote. It deserves to be
noticed that in the cinnabar veins of Almaden, large por-
tions of a rock analogous to euphotide are met with. At
Guarena, and upon the banks of the Guadiana, near Merida,
euphotide occurs in the tertiary beds. On the right bank
of the Guadiana, near Badajoz, the same rock is met with,
associated with dolomite and travertine, or porous lime-
stone, containing fresh water fossils. Sometimes the dial-
lage is distinct in the felspar basis ; it often contains actinote
passing into asbestus, pyrites, quartz, green talcose mica,
and chlorite in small scales. To the south-west of Albu-
querque, there are, fragments of euphotide similar to those
of Almaden, and considerable quantities are found on the
greywacke, which extends as far as Portugal to the west of
this city, in which country it very probably occurs in situ.

Near Cazalla, in the Sierra Morena, large blocks of
euphotide are strewed about, consisting of greenish felspar,
and of olive-green diallage, interspersed with small frag-
ments of protoxide of iron, which are sometimes so abun-
dant as to form the principal portion of the rock. At
Pedroso, Fuente del Arco, and Higueira, rocks possessing
a granitic structure, consisting of felspar and quartz, occur.
They appear to be of the same nature as euphotide. Asso-
ciated with the euphotide of Almaden, there are trap blocks
on the tops of the hills, having often the aspect of basalt,
and are obviously euphotide or diorite, cooled under diffe-
rent circumstances.

2. Mica Slate shewing itself near Albuquerque, in contact
with granite, is composed of a clay-slate basis, impregnated
with mica or talc, and gradually passes into clay-slate.
Near Cordova it also occurs in the midst of transition rocks,
and in contact with granite at Pedroso, where the quartz
predominates, and gives the rock the appearance of gneiss.

3. Secondary Rocks. — These correspond with those of the
rest of Europe, and afford a strong presumption of the

1835.] Estramadur a and the North of Andalusia. 347

uniform nature of the causes which have given origin to
the different formations. They lie over the mica slate in
the following order : clay slate and talc slate, alternating
with greywacke, and always with thick beds of quartz.
Limestone also is common on the heights between Llerena
and Guadalcanal, apparently belonging to the same series
of rocks. The mountain chain extending to the south of
Almaden consists principally of layers of quartz, without
any trace of fossils ; but at the lower grounds, where we
find sandstone and phyllades, passing into psammites,
remains of animals are frequently encountered, similar to
those of the secondary transition rocks of Britain.

In particular, a terebratula, with large whorls, and a
fossil corresponding exactly with the spirifer attenuatus of
Sowerby, have been met with, and similar remains have
been observed at St. Eufemia and Espiel. Hence, it
appears that there have been two periods in the transition
formation of Almaden, but their proper discrimination
would require a very attentive examination.

Clay slate alternating with talc slate, constitutes the
basis of the transition formation of Estramadura. The first
has a fine grain, slightly sonorous, with a beautiful blue
slate colour, and is sometimes separable into very thin
plates. The latter varies a good deal in the relative pro-
portion of its constituents, and passes often into phyllades,
a rock which contains much mica, agglutinated by a sandy
or earthy basis, and frequently resembling the psammites
of the variegated sandstone formation. Greywacke, how-
ever, is the predominant transition rock. Between the
Sierra d' Almaden and the Rio Guadalamez, it is very uni-
form in its structure, and is the only rock met with between
the granite of Albuquerque and Malpartida. It abounds,
although mixed with phyllades, in the neighbourhood of
Talarrubias, Orellana, Espiritus Santi Cabeza del Buey. It
is generally characterized by consisting of compact, hard
and fine grains, with a gray colour.

The quartz rocks do not exist to such an extent as in
Scotland, but are merely found in thick beds subordinate
to the transition rocks. In the hills between Espiritus
Santo and Almadan, the quartz is very compact, resembling
eurite, and frequently passes into sandstone. M. Le Play

348 M. F. Le Play on the Geology of [May

considers that the quartzoze chains have not been elevated,
but have been, as it were, sculptured out by the gradual
degradation of the surrounding country, the constituents
of which are much less durable than the indurated quartz.

The limestone of Llerena is very rich in metals, and forms
the summits of the mountains which run from south-east
to north-west, crossing the road from Badajoz to Seville.
The silver mines of Guadalcanal are situated in hills of
slate and greywacke, at the south-east extremity of this
limestone ridge. More southerly, compact and saccharoid
limestone is often met with, as at Cazalla and Pedroso.

The coal formation does not occur to any great extent
in Estramadura, but, being distributed in small patches on
the surface of the transition formation, throws some light
on the geology of the district. Impressions of equiseta and
filices exist abundantly in the rocks of the coal basons The
valley of Espiel, which is probably united with the coal
bason of Valmez, is surrounded by high transition hills.
The predominating rock is a quartzoze conglomerate, pass-
ing into pudding-stone, and is often impregnated with oxide
of iron.

The inhabitants raise for their own use a little coal, but
never dig deeper than nine or ten feet. It is very friable,
but possesses all the other qualities of good coal. The coal
basin of Fuente del Arco is surrounded by greywacke rocks,
and is situated at the foot of the limestone ridge of Llerena.
At Alanis, where coal has been dug, in addition to conglo-
merates and psammites, an argillaceous rock appears, con-
taining felspar and ochre. The bason of Villa Nueva del
Rio, on the Guadiana, is the only place where coal can be
said to be worked. The surface of the earth consists here
of conglomerate or pudding-stone. Below it are found
layers of coal and slate-clay, which is black, bituminous,
and contains numerous fossil impressions. The coal is of
good quality, but has only been extracted from the super-
ficial bed, by numerous pits which cover the surface. It
is consumed principally by the steam boats, and at the
forges of Pedroso.

4. Tertiary Rocks. — Near Cordova these rocks appear in
the form of shell limestone, of a porous structure, contain-
ing the remains of many animals, and among others^ a

1835.] Estramadura and the North of Andalusia. 349

terebratula and echinus , identical with those found in Corsica.
According to Deshayes these fossils characterize the second
tertiary period, of which there is an example near the Straits
of Bonefacio. The limestone beds have a slight inclination,
and appear to repose on slate and compact limestone, pene-
trated by veins of carbonate of lime. The hills formed of
this modern limestone, are separated from the right bank
of the Guadalquiver, by an alluvial band, forming a small
plain upon which the city of Cordova, with its gardens, is
situated. The left bank is formed of a steep wall of gray
marl, corresponding with the gray marls which accompany
the gypsum of the Paris bason. No organic remains were
observed, but it is probable that they do exist. At Badajoz,
a small chain of limestone hills crosses the course of the
Guadiana, forming a steep escarpment on its bank. On the
west of this precipice reddish-gray marls occur, possessing
the characters of travertine, and near it are found fresh
water fossils. Towards the east, the shell limestone is
replaced by alternate layers of dolomite and compact rocks.
The dolomite is crystalline, with a yellow colour, sometimes
filled with small cavities, and interspersed with rhombohe-
dral crystals. The rock itself is not slaty, but is deposited
in thick beds, which are separated by thin layers of slaty
rocks, which are white, earthy, and contain talc, sometimes
becoming compact. Associated with them are crystalline
rocks, consisting of felspar and amphibole, and crystals of
diallage, resembling euphotide, or the black porphyry of
Almaden. Sometimes, also, they contain green mica,
pyrites, and chlorite. No dolomite is found among the
transition rocks, and hence, M. Le Play conceives that the
dolomite formation of Badajoz is an altered state of the
lacustrine rocks, and that this modification is connected
with the infiltration of masses of euphotide.

Two specimens of this rock afforded, by analysis, the
following constituents : —

Lime 30-0 - 29*0

Magnesia 19*2 - 18-4

Protoxide of iron . . . . 2'6 - 4*3

Carbonic acid 46*4 - 45*2

Earthy matter *5 - 2*2

98-7 - 99-1

350 M. F. Le Play on the Geology of [May

Corresponding to Ca. C + (Mg. /) C *

Over the shell limestone is superimposed, at Cordova, an
argillaceous formation with rolled flints, which has obvi-
ously been transported thither as in Old Castile, Murcia,
Cape Palos, Marbella, and is considered as indicating a
third epoch in the tertiary series. At Badajoz similar
appearances present themselves, in the form of conglome-
rates, with flints, rising about 200 feet above the level of the
Guadiana. The fragments of conglomerate generally consist
of quartz, greywacke, slate and large flints. In the Rio
Gargaliga, reddish quartz appears ; the low plains of Serena
and Guadiana consist of fine silicious sand ; the hills in the
neighbourhood of the Guadiana are covered by clay, with
or without flints, renowned for its fertility, and termed in
the country tierra de barros. In addition to this formation,
numerous more recent disintegrations are observed in dif-
ferent situations, deriving their origin from atmospheric
influences.

Minerals. — Estramadura contains a vast variety of metallic
minerals, which, if properly employed, would raise this
district to the first distinction.

Mercury is found in large deposits in the form of cinnabar,
and native mercury occurs in the hill upon which Almaden is
built. The veins are parallel, almost vertical, and are distant
about sixty-five feet from each other. Their mean breadth
is about twenty-six feet, but sometimes the absolute dia-
meter is double this measurement ; the depth at which they
are worked is about 820 feet. One of these veins is termed
San Diego a levante, and the other San Francisco a levante.

The rocks which the veins traverse are principally quartz
and clay- slate. At the south-west, of the first vein, there is

* Magnesian limestone very often occurs in alternations with porphyry. In
Durham, breccia is connected with the extensive dolomitic beds ; and in Berwick-
shire I have described it (Loudon's Mag. of Nat. Hist. v. 627.) as alternating
with claystone-porphyry. Analysis shewed its composition to be,

Carbonate of lime . . 49*6
Carbonate of magnesia . 44*

Silica 4-

Peroxide of iron ... 1*2
Alumina 1*

99-8

This is, abstracting impurities, = Ca. C -f- Mg. C. — Edit.

1835.] Estramadura and the North of Andalusia. 351

a rock which the miners term freylesca, formed of small
distinct fragments of talc or clay-slate, possessing a dark-
gray colour, with a structure resembling some species of
porphyry. It is more easily worked than the other rocks,
and is conjectured by M. Le Play to be connected with
the formation of the veins. The veins themselves are
formed of compact quartz, impregnated with cinnabar, and
a small quantity of native mercury. Sometimes the matrix
of the mineral is a black bituminous slate, which becomes
white by calcination.

Notwithstanding the thickness of the vein, in consequence
of the good system of mining, its mass is extracted entire.
Frequently pieces of perfectly pure cinnabar are obtained.
A cubic metre (35*317 Eng. cub. feet) of the ore in a rough
state produces 325 kilogrammes (2 cwt. 11 lbs.) of mercury.
The mining is conducted by driving successive levels or
galleries, at different depths. The total depth of the pits
in May 1833 was 307 varas, (841 feet.) The annual product
of the mines of Almaden is 22*000 quintals (1078 tons.)
Hence, this spot alone furnishes twice as much mercury as
all the other mines together, in Carniola, Hungary, the
Palatinate, and Peru.

Silver mines, according to tradition, were anciently
worked in Estramadura and the Sierra Morena. Those best
known are at Guadalcanal. In the middle of the seven-
teenth century silver was raised here and at Cazalla, from
the transition slate, mixed with sulphur, antimony, and
arsenic. Silver is also said to exist about Logrosan and
Zafra ; and M. Le Play heard that mines of this metal had
commenced successfully to the west of Pedroso. At El
Chantre a silver mine is still shewn, but nothing could be
detected among the debris but pyrites and galena.

Lead is found abundantly, in the form of galena, in veins
in the stratified transition rocks. Defourcy found some
specimens to contain the following proportions of silver
and lead.

Lead. Silver.
Cardosa near Llerana .... 793- - 000*63

Los Pobres 752* - 000*47

Truxillo 789- - 000-35

San Calisto, Sierra Morena . . 630* - 000*30

352

M. F. Le Play on the Geology of

[May

Copper occurs in the same circumstances with galena, in
the shape of copper pyrites, blue and green carbonates.
The most common mineral is a mixture of green carbonate
of copper and hydrate of iron. It contains 30 per cent, of
copper, and is found near Talarrubias, where it forms
singular veins on the surface, to the north of Anora, at a
place called Casa Blanca, on the north of Cordova. These
three varieties contain

Oxide of copper .
Water and carbonic acid
Hydrate of iron . . .
Quartz

Metallic copper

Talarrubias.

Casa Blanca.

Cordova. |

37-8
16-4
28-8
16-0

46-1
18-5
29-1
5-0

63-6 j
25-4

6-5

30

99-0

98-7

98-5

30-2

36-8

50-8 !

The same mineral occurs at Garlitos in granite .

Antimony was mined during last century in the mountains
of La Mancha ; and in the bed of the Guadiana large blocks
of sulphuret of antimony are met with.

Iron is plentiful in this district, in the form of red oxide,
passing into fer oligiste, and red and brown hematite,
deposited in layers and veins in the quartz which crowns
the small chains of Estramadura. In the Sierra d'Orellana
vast excavations are observed, which were produced for the
extraction of this metal. On the right bank of the Rio
Guezna there are thick layers of fer oligiste, which supply
the works of Pedroso.

Such is the wealth of this province, which might be raised
to opulence and luxury if the people were stimulated to
industry.

Most authors who have written upon Estramadura,
struck with the limited population, when compared with the
extent of the province, have deplored the retrograde state
into which it has fallen. The symptoms of this falling off
are very distinct on the Guadiana, where large Roman
cities are transformed into country towns. The nature of
the soil, as depending upon the different formations, has
had a decided effect upon the distribution of the inhabitants.
The transition formation is in general much less fertile than

1835.] Estramadura and the North of Andalusia. 353

than the granite or tertiary beds. On the left bank of the
Guadiana we often look in vain for any trace of vegetable
soil.

A fine thick herbage of aromatic labiatae, liliaceae and
asphodelece, growing from the vertical portions of the slate
and greywacke, affords pasturage during the winter and
spring to wandering flocks which pass across New Castile
to the sources of the Tagus.

In May these plains are beautiful, but on the approach
of the heats of summer nothing is seen but a burnt surface,
destitute of trees and bushes, with the exception of a few
miserable oaks, whose wretched foliage only adds to the
dismal nature of the scene. At the bottom of the isolated
chains the case is different, for there vegetation flourishes,
and springs exist which nourish the fruit trees and oranges
as at Alcocer, Orellana, Castuera, &c.

The mountainous parts of the transition formation are
well wooded, and are susceptible of good cultivation.
Between the granite formations of Albuquerque, Malpar-
tida, and Montaches, the surface is covered with cork trees
and other species of oaks ; but these trees are always at
such a distance that the intervals may be sowed with corn.
The inhabitants have no word expressing a wood or forest.
The other mountains which constitute half of the surface
of Estramadura, are covered with thick bushes, eight or
ten feet high, consisting of plants which form the ornament
of our gardens, as Cisti, especially Cistus ladanifer, Pistacia
lentiscus, Arbutus unedo the tree heath, whose root pro-
duces an excellent charcoal, Spanish broom, several
species of rhamni, the common myrtle which is frequent
near Pedroso, and the rose laurel in the bed of streams.
The Sierra Morena is covered with these plants, which give
to it the sombre appearance expressed by its name, (black
mountain.) The granite formation is more fertile than the
preceding, and supports a greater population. And, not-
withstanding the abundance of solid blocks which obstruct
the agriculturist, granite hills, as at Torremocha, are well
cultivated, and are ornamented with oaks whose acorns
supply food for flocks of pigs.

In the same formation is situated Hinogosa, which enjoys
a fertility superior to that of Touraine and Normandy.
vol. i. 2 a

354 M. F. Le Play on the Geology of [May

But it is in the tertiary formations that the population has
been principally developed. The plains of the Guadiana
and Guadalquiver present prospects to the agriculturist
which are sought for in vain over the rest of the country.
It was on this fertile portion of the country that, under the
Romans and Arabs, so many populous cities grew up.
Here are situated Merida, with 4000 inhabitants ; Cordova,
which, in the days of Almanzor, extended for several
leagues along the banks of the Guadalquiver, but is not
now larger than a third-rate town in France ; and Seville,
whose ancient grandeur although no more, contains still
100,000 inhabitants.

In this country, where nature has been so profuse with
her gifts, the whole land, even among the principal cities,
lies desolate and waste, without promising any hope for the
poor or security for the rich. How momentous would be
the change should improved institutions and morals be
introduced. Cultivation might be general, and, together
with the product of the mines, the country would support
a population twenty times as numerous.

The author draws some important inferences in reference
to the causes of the appearances which the country of
Estramadura exhibits.

1 . The inferior transition formation and crystalline rocks
upon which the former repose, are conformable, which
shews that at the period when mechanical deposition began
to succeed chemical eruption, no violent action occurred.

2. The passage from the first into the second transition
period was marked by the appearance of the great chain of
Almaden. The latter, after this event, formed the crest of
a small island, running in the direction from east 40° north
to west 40° south. This island was formed at the same
time that Britain and the north of Normandy began to ap-
pear, its banks being inhabited by the same kind of mol-
luscous animals which existed in the latter.

3. The termination of the second transition period was
marked by the elevation of the land of Estramadura, but
this first revolution did not raise it to the level which it at
present possesses. Its surface had completely emerged,
with the exception of some small lakes or gulfs where the
coal formation was afterwards deposited.

1835.] Estramadur a and the North of Andalusia. 355

4. The coal basins were not all originally concentrated
in the Sierra Morena, where we find the present traces of
them ; but the deposits which were situated on the Guadiana
have disappeared under the influence of the same causes,
which have been already noticed as having wasted the
surface of the land.

5. The tertiary basin of Badajoz reposing immediately
upon the transition formation, it follows that the fresh
water limestone appearing to occupy the inferior part of this
formation was deposited in a basin which did not exist
before the tertiary period. This affords proof of the occur-
rence of movements of the land at an earlier period, in
addition to the vertical position of the marls and fresh water
limestone of Badajoz. The characters of the euphotide and
diorite, and their interstratification with the dolomite,
shew that there is an intimate relation between the most
recent revolution of the land in Estramadura, and the
appearance of these crystallized masses. This connexion is
similar to that which Dufrenoy has noticed between the
revolutions of the third tertiary era on the two declivi-
ties of the Pyrenees, and the eruption of these crystalline
rocks, composed of felspar and actinote, which he has
termed ophites. That this relation does actually exist
between the transported formation of Castile and Estrama-
dura, and the third tertiary epoch of' the south of France,
is further proved by the circumstance that arragonite occurs
in both places. The crystals observed in collections come
principally from Molida d'Aragon and Mingranilla, near
Cuenca.

With regard to the direction of the chains and stratified
rocks, Le Play considers that the first revolution which
took place between the two transition periods, produced in
the ancient transition strata, a rupture from east 40° north
to west 40° south, a direction corresponding with the slate
in the hills of Westmoreland, Hundsriick, &c.

This elevation is exhibited in a regular manner in the
Almaden chain, and directs the course of the rivers.

The modern transition formation was elevated at the
same period with that of Britain and Normandy. The
mechanical action which produced this elevation appears to
have exercised its chief force in a line passing through the

2 a 2

356 M. F. Le Play on the Geology of [May

axis of the granite basin of Torrenulano and Hinogosa, from
west 12° north to east 12° south. This direction is indicated
by the regular stratification of the slate and greywacke.
The same appearances are exhibited to the north of Cordova
in the hills which lie on the frontier of Portugal, to the
west of Albuquerque, but there, regularity is in many places
interrupted by more recent dislocations. An elevation pos-
terior to the deposition of the coal appears to have passed
from east to west 72° north, and presents itself regularly in
the chain of Solana, in the country of Montanches in the
Sierra de San Servan, in the neighbourhood of Pedroso,
and in the coal formation of Villa Nueva del Rio.

The revolution which has followed the third tertiary
period, from east 17° north to west 17° south, is clearly
indicated by the course of the rivers Duero, Tagus, Gua-
diana, and Guadalquiver. It is a remarkable fact, that
some of the fissures which contain the mercury of Almadcn
follow the same direction as the hills in which they are
situated. The author considers, that the production of
these veins was contemporaneous with that of the ophites,
which is confirmed by the circumstance of round masses
of ophite being occasionally found in the cinnabar. It has
been long thought that mercury was a recent formation,
but the facts here stated shew that its origin is more
modern than geologists had ever conceived. In comparing
Estramadura with the rest of Spain, M. Le Play considers
that the revolution which occurred after the first transition
period, originated the rocks of Almaden, the eastern part
of the Pyrenees by Castres and Carcassone, the Sierras
D'Albarracin and Molina, as well as the granite and old
stratified rocks, extending between Cape Ortegal and Cape
Finisterre. These all extend east 40° north.

After the second transition era, a revolution running
west 12° north, affected the whole of Spain, elevating the
Pyrenees in Asturia, the modern transition portion of
Estramadura, and probably, also the whole country between
the Tagus and Guadalquiver. To the south, it produced
also the Alpujarras, the Contraviesa, the Sierra de Lujar,
and all the mountainous country between Malaga and
Almeria. If a line be drawn through the small hills which
form the eastern part of the Sierra de San Servan, it will

1835.] Estramadura and the North of Andalusia. 357

form with the meridian an angle of 15° towards the west,
and will run from Cape Ortegal to the pillars of Hercules.
It thus points out a series of dislocations, which all assume
the same direction, and which formed the isthmus which
united Spain with Africa. The revolutions during the
secondary period acted principally in the south of Spain.
At the end of the secondary period, the revolution which
produced the Pyrenees, gave to the mountains running
from Cape Ortegal to Catalonia, the elevation which they
at present possess. The coast between Catalonia and Cape
Creuss was formed by the elevation of the Pyrenees, and
several islands varied the surface of the sea, which ex-
tended from the Alpuj arras chain to Corsica. On its
shores lived the echini and terebratulce of Cordova. But a
great revolution speedily supervened, which formed the
coasts of Catalonia, Valencia and Murcia, and elevated the
western Alps.

Cape Forcas in Africa and the islands of Alboran are in
the same line of elevation, and probably, constituted
another isthmus, which joined Africa with Spain. The
observations of Silvertrop upon the tertiary strata of
Murcia, demonstrate that the third tertiary formation,
reposes in horizontal layers on the inclined strata of the
second era, confirming the theory of Beaumont. The
strait of Gibraltar was formed by the same rupture which
produced the western Alps. At this period, an immense
pressure appears to have been created under the peninisula,
which elevated it to its present position, and projected
crystalline rocks or ophites through its substance. Hence
it is, that we find these rocks in mountains of different
ages, and that the latter affect an east north-east direction,
which characterizes the elevation at this period. The great
snowy chain which separates the two Castiles, the Sierra
Morena, presents the character of mountains formed suc-
cessively, and then re-united at a more recent period by
another eruption. The latter are composed of three dis-
tinct parts, in relation to the stratification of the rocks and
its direction. This revolution formed the Spanish Alps, the
Sierra Nevada, and the coast between Malaga and Gibral-
tar. By raising the Southern coast of Spain the lands which
united the latter with Africa were lowered, and the Strait of

358 Mr. Tomlinson s Experiments and [May

Gibraltar was formed at the time that the elevation of the
tertiary strata of France destroyed the ancient strait, and
joined Spain to the continent of Europe. The recent date
of this dislocation is confirmed by the direction of the
ophites, and the similarity of the plants and animals as
observed by Bory de Saint Vincent on the opposite coasts
of Africa and Spain.

Article IV.

Experiments and Observations on Visible Vibration.
By Charles Tomlinson, Esq.

" The subject is far from being exhausted ; and, indeed, there are few branches
of Physics which promise at once such amusing interest and such important
consequences in its bearings on other subjects." — Hersciiel.

1. The principal object of Philosophy is to explain as
much as is known of the code of laws by which the material
universe is governed, and to discover those laws which have
hitherto eluded the search of Philosophers.

2. As a discoverer of a law of Nature is more worthy
than an expounder, the votaries of modern Science have
been and still are engaged in promoting the dignity and
happiness of man, by increasing efforts to extend the
boundaries of knowledge by a more familiar acquaintance
with Nature's Book; with a code of laws which we are
bound to consider perfect in all respects, and commencing
its operations at a time when man first began to inhabit
this globe : so that, when we hear of the discovery of a new
law, we must not refer its novelty to Nature, but only to
ourselves. Human laws may be created, modified, and
changed to suit new emergencies, but every occurrence in
Nature is referable to a law which has existed, at least, as
long as man himself.

3. But philosophers disagree ! Yes ; and they do so
because the law on which they differ is imperfectly explained,
or not understood. As soon, however, as the law is well
appreciated, all doubts and difficulties are removed ; for it,
in common with other physical laws, is reduced to a propo-
sition remarkable chiefly for its exquisite simplicity.

1835.] Observations on Visible Vibration. 359

4. Among the Sciences which have been advanced more
or less towards perfection, the Science of Sound seems to
have shared an uncommon neglect, and, considering its
high importance, we are naturally surprised that no syste-
matic work, including details and recent discoveries in the
Science, exists. Many Philosophers of high character have
of late years added much, but their results are still con-
fined to the journals in which they first appeared, and most
cordially ought we to desire that some master mind would
devote itself to a full developement of this beautiful science.

5. I believe that Chladni, a German philosopher, about
the year 1787, first propounded the general law, that, in
order to produce a musical note from a glass containing a
liquid, both glass and liquid must vibrate in unison as a
system. It will be seen, however, in the course of these
experiments, that this law (if such it be) is by no means
universal in its application.

6. Chladni also first rendered vibration visible, and
reduced visible vibration to a system. His method con-
sisted in strewing sand on glass plates, which, when
vibrated, caused the sand to arrange itself into various
beautiful forms ; and, by means of experiment and calcula-
tion, he constructed tables of them, which have since been
extended considerably by Wheatstone and others.

7. If a glass containing water be vibrated by moving a
moistened finger round the edge, the water will undulate,
but the form of the undulse will not be very distinctly seen
on account of the length and transparency of the fluid.
Now, it occurred to me that by employing a denser fluid
the figures would be stronger, and better defined.

8. I accordingly poured about a fluid ounce of mercury
into a foot glass, and, as soon as the note was produced by
moving the moistened finger round the edge of the glass,
the mercury assumed a very beautiful appearance. A series
of concentric circles or bands of undulse were formed, the
centre of the mercury being the common centre of the
whole, round which centre a star appeared to revolve in
the direction of the finger, the radii of the star seeming
independent of the undulating bands. Within these bands
there also appeared a square figure with rounded corners,
which may be very distinctly seen by twilight, where the

360 Mr. Tomlinsoris Experiments and [May

undulse reflect the light well, and the space within this
rounded square does so imperfectly. I should also observe
that the surface of the mercury resembled for the most part
the case of an engine-turned watch, and the apparent revo-
lution of the star was in the direction of the linger, from
right to left, or from left to right, and the number of the
radii seemed to depend on the rapidity with which the
finger was passed round the edge of the glass, as well as on
the size of the vessel used, and the extent of the mercurial
surface.

9. Now, it is known that a body, a foot glass, for instance,
in sounding, contains a certain definite number of nodal
points or divisions, the vibrating portions between the
divisions performing their vibrations independently of each
other. These nodal points are points of rest, or at least, of
minimum vibration, and the parts of the mercurial surface,
which are comparatively quiescent during the vibration, are
lines which pass from the circumference to the centre of
the mercury, while the undulating rings, being in motion,
give an apparent motion to the star formed by the nodal
lines.

10. Dr. Thomas Young, in his Lectures on Natural
Philosophy, (vol. i. p. 385.) states, " that a vibrating glass
or bell divides, in general, into four portions vibrating
separately, and sometimes into six or eight; they may
readily be distinguished by means of the agitations excited
by them in a fluid contained in the glass." Now, I have
observed several and I think better modes of discovering
the nodes in a glass or bell. For instance ; procure # two
foot glasses, as perfectly in unison as possible, and about
three inches in diameter ; place on the glass, the nodes of
which are to be ascertained, a piece of very slender copper
wire, terminated at each end with a sort of half loop or
hook, so as to be free to move in the plane of the circle
described by the rim of the glass, and yet not to fall off
during vibration. Place the glasses on wood, or other good
conductor of sound, and vibrate with the moistened finger

* If two unisonant foot glasses cannot be procured, or if it be inconvenient to
accord them by water or mercury, the wire can be placed on one glass, and the
vibration produced by passing the moist finger round the exterior half, and the
result will be the same.

1835.] Observations on Visible Vibration. 361

the first glass ; the wire on the second will vibrate strongly,
and seek the nearest nodes and remain there. These two
nodes are of course exactly opposite to each other, and may
be marked with a dot of ink on the side of the glass imme-
diately below. The two other nodes are midway down, as
may be seen by moving the wire away from the two first
nodes, so as to be within the sphere of attraction (if I may
so speak) of the two second ; the wire will almost immedi-
ately attain those two points, and if the finger be slackened
in its pressure, so as to produce a clear but not a full note,
in order that the wire may not be jerked, and the finger be
then removed, the wire will invariably rest on the nodal
points.*

1 1 . Various forms of wire may be adopted ; a half circle
terminated with loops or hooks ; or a right angle, the sides
of which simply rest against the glass, while the apex
points towards the bottom of the glass ; or what, perhaps,
is most striking and satisfactory of all, four curved pieces
of wire, resembling ladies' hair pins, only with very short
legs, maybe employed, one leg within and another without
the glass. On placing these midway between each of the
four nodes, and vibrating the unisonant glass, the wires will
find out the nodes and continue to vibrate there.

12. I need not, of course, remark that the nodes are not
always, strictly speaking, at four equidistant points of the
same circle. One direction may contain more or less matter
than another, and when this is the case to an appreciable
extent, there will be an interruption in the vibration. For
instance : I find that in foot glasses, the rim of which is about
three inches in circumference, there are always four nodes which
are, or ought to be, equidistant ; if this be not the case, the
space between the first and second node will vibrate quicker
or slower than the space between the second and third, and
so on. Now, if one space vibrate 100, and another 101
times in a second, there will be an interference, and, conse-
quently, a momentary interval of silence. This may be
observed in a foot glass under the circumstances before
mentioned ; if the note be produced by the moistened finger,

* I should observe, that if, when the wire is vibrating at the node, one end be
moved away a little from that point, it will instantaneously regain the node, as if
it were a metallic spring.

362 Mr. Tomlinsoris Experiments and [May

and then removed, and the ear be applied close to the
glass, the note will be distinctly heard to consist of such
sounds as

woo, woo, woo, woo, icoo,
and so on until all vibration ceases.

13. In my early attempts to ascertain the nodes by means
of wire, I observed a very curious effect : I had employed
a piece of iron wire, entirely free from magnetism, placed
one end at the bottom of the glass, and the other resting
against the »side. On vibrating the glass containing the
wire, I found that it invariably turned towards the north,
and continued to vibrate there in the plane of one magnetic
meridian. I employed copper and brass wire, always with-
out the same effect. I therefore assured myself of the cor-
rectness of the first experiment, and got two or three friends
to repeat it, but the result was undoubted. I even found
that the result was obtained when the glass was half filled
with water or oil, so as to cover the wire, and that the
motion of the wire, and its retention towards the north,
seemed facilitated by that fluid.

14. In explaining this experiment I must refer to the
mode of inducing magnetism by percussion, such as an
inclined poker or bar of iron when struck by a hammer.
The blows strongly vibrate every particle of the mass of
metal, and, by a process not clearly comprehended, mag-
netism is induced. Now, in the above experiment, vibra-
tion, by a somewhat analogous process, renders the wire
slightly magnetic, and being free to move, it is of course
attracted by the magnetic force.

15. To return, however, to the vibrating mercury, we
must consider that as the vibrating parts of the glass act at
right angles to the mercury, the edge of that fluid is, as it
were, attracted and repelled, and the the first band of
undulae moves in the direction of the finger, as may be
shewn by placing a small shot or other small body on the
mercury, leaning from its convex edge against the side of
the glass. The attractions and repulsions that I speak of
may be illustrated by surrounding the mercury with a circle
of small shot at the circumference. If the glass be then
vibrated the shot becomes agitated in a singular manner.
All seem actuated by a uniform vibrating motion, and the

1835.] Observations on Visible Vibration. 363

sound produced by the shot is of a peculiar kind ; their
vibration even continues for some seconds after the finger
is taken from the glass, in consequence of the momentum
they and the glass have acquired, and the note gradually
becomes more acute and faint.

17. If a large glass be employed in the above experiment,
(15) and the finger be well moistened, and in its rotation
pressed rather heavily on the edge of the glass, so as to
produce a strong full noise, some of the shot will start from
the circumference to the centre, and there remain in a state
of rest. Indeed, the tendency of globular bodies is to the
centre, where they remain in a quiescent state.

18. A totally different appearance can be communicated
to the surface of the mercury, by moving the finger, not in
continued order round the glass, but with a jerking kind
of motion, pressing heavily, and resting for a moment at
intervals of about an inch. The mercury is then thrown
into broad concentric circles, sometimes perfect and some-
times broken.

19. The mercury can also be made to assume a variety of
forms, according to the mode of vibrating the glass, and
the quantity of mercury employed, by drawing a bow against
the edge or edges of the glass ; by pressing the finger more
or less heavily ; or by passing it round with greater or less
rapidity.

20. When the mercury is very clear the edge of the glass
will be seen distinctly reflected in it ) if a large soda water
glass be employed, and the finger moved slowly round, the
reflected edge will be seen thrown into a series of nodes
and ventral segments. The forms are very various and
interesting, and depend on the circumstances just men-
tioned (19.) If the mercurial surface be covered with a
thin coating of oil, the edge may still be seen distinctly
reflected, but it is not disturbed during vibration. (23.)

21. The glass below the mercury vibrates but little, nor
does the mercury vibrate much below its surface ; for the
hand can be placed round the inside of the glass below the
surface of the fluid, and the vibration of both seems unaf-
fected, except that the note does not sound so frill or so
clear.

(22.) The same observation applies when gelatinous and

364 Mr. Tomlinsons Experiments and [Mat

oleaginous substances are employed instead of mercury,
except that they do not vibrate.

23. I now proceed to notice the effects of this method of
vibration on other fluids, and their effects on mercury.
The fixed oils and sulphuric acid, I find, will not vibrate, and
when poured on the surface of mercury they entirely prevent
its vibration.

24. I attribute this preventive effect to the consistency
of those fluids, for muriatic acid vibrated and permitted the
mercury to vibrate. Nitric acid also vibrated, and its de-
composition seemed retarded by the vibration. I could not
distinguish whether the mercury vibrated ; but when two
drachms of acid were diluted with the same bulk of water,
both dilute acid and mercury vibrated readily.

25. When oil is poured on the surface of the mercury,
the vibration of the latter may be restored by the addition
of water ; the oil rising to the surface of that fluid allows
the mercury to vibrate. If, however, oil of cloves be em-
ployed, or any oil of greater sp. gr. than water, the water
will remain on the surface and vibrate, while the two strata
of fluids below remain quiescent; but, if sulphuric acid be
diluted with about its own bulk of water, it will vibrate and
allow the mercury to vibrate also.

26. At a temperature of 238° olive oil vibrates, or rather
undulates at or near its circumference, but all motion soon
ceases as the temperature falls.

27. Sperm oil at 340° vibrates as readily as water ; its
ready vibration decreases, of course, as the temperature
falls, and at about 180° its vibration ceases.

28. Sperm oil at 300° poured on mercury at the atmos-
pheric temperature vibrates, and allows the mercury to vibrate
as effectually as if it were but water. The temperature of the
oil rapidly decreases, in consequence of absorption of heat
by the mercury and radiation, but the most singular part of
this experiment is, that after the oil has ceased to vibrate,
the mercury vibrates readily, and turns the oil round at a
temperature so low as 80°, and a needle placed on the sur-
face of the mercury beneath the oil, turns slowly round in
the direction of the finger, as also small shot at the cir-
cumference.

29. Castor oil at 368° vibrates, but not readily. On

1835.] Observations on Visible Vibration. 365

adding about an equal bulk of mercury the temperature
fell to 190°, when both oil and mercury undulated a little,
but all motion ceased in a minute or two as the tempera-
ture fell.

30. A compound of castor oil and alcohol did not vibrate.

31. Rape oil, at the ordinary temperature of the atmos-
phere shews not the slightest indication of vibration ; nor
indeed, do any of the oils at ordinary temperatures (23)
but rape oil at 310° undulated at the circumference. On
adding about an equal bulk of mercury, the temperature
fell to about 140°, and both fluids undulated at the circum-
ference. A needle on the mercury beneath the oil was
quite unaffected. At 126° not the slightest motion was ap-
parent in the oil.

32. Linseed oil at 367° undulates freely and swims nar-
row slips of writing paper round in the direction of the
finger. The paper, however, soon sinks, shewing the small
sp. gr. of the heated oil.

33. Sulphuric acid, (sp. gr. 1*839) was heated to 239°,
when it vibrated almost as readily as water. After a short
time, about an equal bulk of mercury was added and the
temperature fell to 95°, but neither fluid vibrated.

34. The muriatic, nitric, acetic, and pyro-ligneous acids
are good vibrators, the two latter even better than water.
A narrow slip of writing paper placed on the surface of
either of the two latter, is borne round quickly in the direc-
tion of the finger

35. A mixture of sulphuric acid four parts, and alcohol
one part, vibrates well.

36. The saponaceous compound, procured by adding
liquor ammoniae to oil and water, does not vibrate.

37. I have already noticed the proposition of Chladni,
(5) that in order to produce a musical note from a glass
containing a liquid, that both glass and liquid must vibrate
together in unison as a system. Now in the above experi-
ments, whether the liquids that I used vibrated or not, I
always procured a full, clear, musical note from the glass ;
from the densest oil that I employed, which was castor oil, to

the most limpid sperm oil. I have even found, contrary to
the general and received opinion, that a glass containing a
liquid in a state of active effervescence, will yield a full and

366 Mr. Tomlinson s Experiments and [May

clear musical note by j)assing the moistened finger round the
edge of the glass, as has been done in all these experiments.
If to dilute nitric acid, sufficient to half fill a large soda
water glass, three or four lumps of carbonate of ammonia
be added, an active effervescence will of course ensue ; but
the same strong, clear note can be produced during the
most active effervescence, when small bubbles of carbonic
acid rise more than half an inch above the surface of the
liquid, and the only difference worthy of remark is, that
the moment the finger is removed from the glass the note
ceases ; whereas, with the oils and other liquids, whether
they vibrate with the glass or do not vibrate at all, the note
continues audible for a few seconds after the finger has left
the glass.

38. In the last experiment if the glass be struck it will
not, as Chladni says, ring. This striking is, however, at
best, but a very imperfect mode of vibrating a glass. It is
necessary that every part of the circle should receive an
impulse, which it can only do by the moistened finger. If,
however, the liberation of carbonic acid be such as to cause
bubbles of gas to rise up to the brim, the vibration will
certainly be deadened ; as when a saturated solution of
carbonate of soda is contained in the glass, if a saturated
solution of tartaric acid be added, the liquid will rise up
and interrupt the vibration, but if the acid be added in
lumps, the note will be uninterrupted.

39. I now proceed to notice the effects of solids placed
on the surface of the vibrating mercury. I placed upon it
a small magnetic needle, and as soon as the note was pro-
duced by means of the moistened finger, the needle revolved
in a contrary direction to the finger, and contrary to the
apparent motion of the star, (8.)

40. I then employed a two inch bar magnet, and this
during vibration, assumed a position east and west, as the
finger was moved from left to right, and west and east as
the motion of the finger was reversed.

41. I found, however, that unmagnetised iron wire re-
volved in an opposite direction to the finger, and as I saw
nothing in the experiment (40) to induce me to believe
that electricity was induced, I concluded that the efforts
of the bar magnet, which was a powerful one, to regain its

1835.] Observations on Visible Vibration. 367

natural direction, prevented the vibrating force from bear-
ing it round beyond east and west and west and east.

42. With impure mercury I found the motion of the
needle or wire much retarded, and on covering the surface
of clean mercury with a very thin coating of lycopodium
dust, the motion of the needle was altogether suspended.

43. I found pieces of wood, cork, paper, cotton, wool,
camphor, camphor in a state of ignition, a silver amalgam,
&c, all to follow the same general law of revolving, con-
trary to the direction of the finger.

44. I therefore, began to inquire, whether there might
not be opposing currents in the vibrating mercury, which
had hitherto escaped my notice, as indeed, was likely to
be the case, as the time that I could devote to this investi-
gation, out of an absorbing and anxious profession was so
limited, that I could only work by artificial light ; and I
afterwards found that in order to detect minute appearances,
a good natural light was indispensable.

45. I need not now detail the various experiments which
led me to the conclusion, that what I had suspected, was
really the case : that in vibrating mercury there is a series
of concentric currents ; that the outer current revolves in the
direction of the finger, but there are inner currents revolving
in an opposite direction, the number or force of which, is
greater than those which revolve in the direction of the finger .

46 In a second paper, I shall resume this subject. I
must, however, observe, that in performing these experi-
ments, the mercury should be perfectly clean and free from
amalgam ; and that in manipulating with the heated oils,
foot-glasses of about 3 inches diameter should be employed
and procured as thin as possible. The oils can be heated in
a Florence flask with the neck cut off to allow free evapo-
ration to the water contained in them. The glasses must
be heated first, and the oil poured in very gradually ; the
temperature is then to be noted, and the glass vibrated the
moment after. By this method, the glasses, if well an-
nexed, will bear a temperature of from 300° to 400°. It is
adviseable also to place the whole apparatus in a small tray,
in case of fracture either of the flask or glass.
Brown Street, Salisbury,
2Sth February, 1835.

368 Mr. Walker on the Adjustment of the Eye to [May

Article V.

On the Adjustment of the Eye to Distinct Vision at Different
Distances. By John Walker, Esq. Assistant-Surgeon
to the Manchester Eye Institution.

The adjustment of the eye to the distinct vision of objects
at various distances, is a question which is still considered
to remain undetermined.

It is not my purpose to enter into a history of the various
explanations offered, but rather to point out a very simple
experiment, which, I think, elucidates the point in dispute.
I may, nevertheless, first observe that it is generally admitted
that when the eye, from contemplating an object at some
distance, suddenly fixes itself on some other object very near
to the organ, there is a contraction of the pupil always
accompanying this change.

From this circumstance many have been led to believe
that the alteration in the size of the pupil is the chief, if not
the sole, change which occurs in the eye during this opera-
tion. Sir David Brewster has related experiments which
are easily verified, and which prove that the application of
a bright light to the eye, causing a contraction of the pupil,
enables the organ to adjust itself to distinct vision at a less
distance than before. Dr. Wells has also established the
fact that when the pupil is dilated by belladonna, the power
of adjustment is lost. It is also well known that when an
object is brought so close to the eye as to be invisible, by
looking at the same object, at the like distance, through a
a pin-hole perforated through a card, it becomes quite dis-
tinct. All these circumstances seem to favour the opinion
that it is merely the size of the aperture, through which the
rays of light are admitted into the eye, that regulates the
adjustment ; but still they are considered fallacious, and it
is thought that some alteration in the refracting media is
indispensable.

It occurred to me, whilst debating these facts in my mind,
that, with an artificial eye-ball, which I possess, fitted up
with a cornea, iris, lens, and a retina of ground glass, each
bearing its proper relation to the others, by varying the

1835.] Distinct Vision at Different Distances. 369

size of the pupillary aperture, we might discover whether
any other action, besides that of the pupil, was necessary to
effect the change in question. With this instrument the
following observations were noticed. The pupil being of a
moderate size, a small object, placed within a few inches of
the cornea, was represented on the retina in a very shadowy
and indistinct manner. On contracting the aperture, which
was done by covering the iris and pupil with a piece of black
riband, perforated in the centre, the picture of the object
appeared beautifully clear and well defined. Now, here
there could be no vital action, no change in the figure or
position of the lens, nothing but the alteration in the
dimensions of the pupil, and yet the desired effect was
produced in the most satisfactory manner. With the same
instrument, it is demonstrable, that if the lens be removed,
and the pupil remain of the natural size, no object whatever
will be represented on the retina ; but, with a contracted
pupil, and the lens still absent, a very fair outline of any
object will be clearly and distinctly seen.

Experiments of all sorts, I am well aware, generally ap-
pear more determinate and conclusive to their authors than
to indifferent individuals ; and, when they are anxious to
establish any particular theory, they do not easily see
objections, which to others are sufficiently apparent. It is
therefore not unlikely that I may have overrated the impor-
tance of these experiments, when I say that, to me, they
appear to settle the point at issue. If, however, I shall
have arrived at an unsound conclusion, I must then throw
myself back on the novelty and interest of the facts as my
only apology.

Article VI.

Account of some new Species of Minerals containing Barytes.
By Thomas Thomson, M.D., F.R.S., L. and E., &c,
Regius Professor "of Chemistry in the University of
Glasgow.

The species of barytes minerals hitherto described by
mineralogists are but few in number. The sulphate and
carbonate have been long known. When to those we add
vol. i. 2 b

370 Dr. Thomas Thomson on some new [May

the baryto-calcite of Brooke, and the stromnite of Dr. Trail,
together with harmotome and brewsterite, we enumerate
almost all the species of minerals containing barytes at
present known. Having, during an examination of the
mineral kingdom, in which I have been occupied for the
last eight years, met with several other minerals containing
barytes, and differing specifically from those already known,
it may, perhaps, be acceptable to mineralogists if I give a
short account of the most remarkable of those in this place.
1. Calcareo- Sulphate of Barytes. — This species, though
hitherto overlooked by mineralogists, occurs rather abun-
dantly in the lead mine of Strontian. This mine, as has
been long known, constitutes a vein in a mountain, con-
sisting partly of granite and partly of gneiss, and the vein
divides the granite portion from the gneiss. The gangue of
this vein consists of carbonate of lime, carbonate of stron-
tian (towards the bottom,) sulphate of barytes, harmotome,
calcareo-sulphate of barytes, &c. This last mineral pro-
bably has been overlooked, because it never occurs in the
state of crystals.

Colour, snow white; texture, foliated; very frangible;
translucent on the edges.

Hardness, 2- 75 on Mohs's scale; specific gravity 4*1907.
Before the blowpipe decrepitates, but does not fuse. When
subjected to analysis I obtained the following constituents :

atoms.

Barytes i . . 48*945 -

Strontian . . 0*790 -

Lime .... 6*605 -

Sulphuric-acid . 35*230 -

Silica. ... 4*140 -

Alumina . . . 3*460 -

Protoxide of iron 0*450 -

Moisture * * 0*565

100*185
We see that the sulphuric acid almost exactly saturates
the barytes, strontian, and lime. From this it can scarcely
be doubted that the other constituents are merely acciden-
tally present, and do not constitute an essential part of the
mineral.

1835.] Species of Minerals containing Barytes. 371

If we include the strontian with the lime, the mineral is
obviously a compound of

2 atoms sulphate of lime
5 atoms sulphate of barytes

or (which comes to the same thing)
1 atom sulphate of lime
2£ atoms sulphate of barytes. ,
The probability is, that this mineral has been hitherto
confounded with sulphate of barytes. When we find the
specific gravity of that sulphate stated as low as 4*2984, as
it is by Hatiy, or 4*136, as it is by Hoffmann, there can be
little doubt that the specimen examined was, in reality, a
calcareo-sulphate .

2. Baryto-Calcite. — I have given this name, perhaps
improperly, (as Brooke had already appropriated it to
another mineral) to another species of calcareous sulphate
of barytes, which occurs in Yorkshire, between Leeds and
Harrogate, connected with the millstone grit and moun-
tain limestone which occur in such abundance in that
country. But I state this as the situation solely on the
authority of the mineral dealer from whom I purchased the
specimen.

Colour, white, with a slight shade of blue ; texture, foli-
ated ; translucent when in thin plates ; lustre, silky ; hard-
ness, 4* ; exceedingly brittle, and very easily frangible.
Specific gravity 3*868*

Its constituents, by my analysis, are

Sulphate of lime . . 71*9 or 4| atoms.
Sulphate of barytes . 28*1 ,, 1 atom.

"100-

The foreign matter amounted to about 1J per cent. It
consisted of ironshot sand, probably introduced by the infil-
tration of water.

3. Sulphato- Carbonate of Barytes. — This mineral occurs
in Brownley Hill mine, in the County of Cumberland. I
first saw it in a collection of minerals exposed for sale in
Glasgow in November 1834, by Mr. Cowper, a mineral
dealer from Alsten Muir. Colour, snow white.

The specimen consists of a cengeries of very large six-sided
prisms, terminated by low six-sided pyramids. The surfaces
were so rough and irregular that it was impossible to measure

2 b 2

372 Dr. Thomas Thomson on some new [May

the angles, even with a common goniometer. The only-
angle of the prisms that it was possible to try, measured
about 130°, shewing that the prism could not be regular.
Three cleavage planes were rather obscurely perceptible
They were parallel to the faces of an obtuse rhomboid,
which seemed to meet at angles of about 100° and 80°.

Texture, foliated ; lustre, vitreous ; translucent ; hard-
ness about 3* ; specific gravity 4*141.

On subjecting it to analysis I obtained

atoms.

Sulphate of barytes

. 34-30

- 1-

Carbonate of barytes .

. 64-82

- 2-2

Carbonate of lime . .

. 0-28

Moisture

. 0-60

100-00
From this analysis I think it probable that the mineral
is a compound of

1 atom sulphate of barytes.

2 atoms carbonate of barytes.

Sp. 4. Calcareo- Carbonate of Barytes. — I give this name
to a mineral first described by Mr. Brooke, # and called by
him baryto-calcite. This name I could not adopt, for a
reason that will appear when the next following species is
described.

It exists in considerable quantity at Alsten Muir, in
Cumberland, both crystallized and massive.

Its colour is white, with a shade of gray, yellow, or green.
Cross fracture, uneven or imperfect and conchoidal.

The primary form of the crystal is an oblique rhombic
prism.

Pon M or M' 102° 54'
M on M' 106° 54'

The obtuse edges of the prism are almost always replaced
by tangent planes.

Lustre, vitreous, inclining to resinous ; varies from trans-
lucent to transparent ; hardness 4. Specific gravity, as
determined by Mr. Richardson in my laboratory 3*6363.

Before the blowpipe it does not fuse per se, but melts
easily with borax and biphosphate of soda into a trans-
parent glass.

* Annals of Philosophy, (Second Series) viii. 114.

atoms

62-20

■ 5-077

31-65 ■

■ 5064

0-30

0-85

315

1835. J Species of Minerals containing Barytes. 373

Its constituents, as determined by Mr. Richardson in my
laboratory, are,

Carbonate of barytes . .
Carbonate of lime . . .
Sulphate of barytes . .
Peroxide of iron . . .
Water, or volatile matter

98-15
It is obviously a compound of

1 atom carbonate of barytes.
1 atom carbonate of lime
Sp. 5. Bicalcareo- Carbonate of Barytes. — This mineral was
(among others) exposed for sale in Glasgow in November
1834, by Mr. Cowper, a mineral dealer from Alsten Muir.

1 purchased a specimen, and subjected it to chemical ana-
lysis, because it appeared to be new. Colour, snow white.

Crystallized in beautiful dodecahedrons with triangular
faces, composed of two six-sided pyramids applied base to
base. The faces were not bright enough to admit of mea-
suring their inclinations to each other. The inclination of
a face of one pyramid to the corresponding face of the other
was about 132° and the angles of the plane separating the
two pyramids were about 120°. Only a single cleavage
could be observed.

The crystals were in groups, upon a white crystallized
substance, which I did not analyze, but it had the aspect
of sulphate of barytes.

Lustre, vitreous ; cross fracture, uneven ; some imperfect
appearance of a foliated structure ; translucent ; hardness
2-25. Specific gravity 3-718.

When dissolved in nitric acid it left 0*75 per cent, of
sulphate of barytes. The moisture, which rather exceeded

2 per cent., was doubtless hygrometrical. Abstracting
these bodies, which I considered as foreign, the constituents
were atoms.

Carbonate of barytes . . . 49-31 or 4*02
Carbonate of lime .... 50-69 „ 8-01

100-

374 Dr. Thomas Thomson on some new [May

This is obviously

1 atom carbonate of barytes.

2 atoms carbonate of lime.

Thus, it contains exactly twice as much carbonate of lime
as the baryto-calcite of Brooke, though the constituents of
the two minerals are the same. It was the necessity of
having names by which these two minerals could be dis-
tinguished from each other that obliged me to alter the
name imposed by Brooke, and to adopt the terms calcareo-
carbonate, and bicalcareo- carbonate of barytes.

Sp. 6. Bary to- Sulphate of Strontian. — This species is
found in Drummond Island, in Lake Erie, and also at
Kingston, in Upper Canada. I got specimens from the
former locality from Major Menzies, and from the latter
locality from Dr. Holmes of Montreal.

The colour is white, with a very slight shade of blue.

The texture is laminated, and the laminae, which are
obviously imperfect crystals, diverge so as to form a kind
of pencil.

Brittle; very friable; hardness 2*75. Specific gravity
3-921.

Before the blowpipe in the platinum forceps, becomes of a
dazzling white, but does not easily fuse. Melts readily with
carbonate of soda into a transparent colourless bead, which
becomes white and opaque on cooling. With borax it fuses
easily into a white opaque globule.

Its constituents are atoms.

Sulphuric acid . . . 40-202 - 8-04 - 10*

Barytes 23*059 - 2'43 - 3-02

Strontian 35*724 - 5-49 - 6-82

Protoxide of iron . . 0*588 - 0*13 - 0*16
Water 0-720 -

100-360
This is obviously equivalent to

3*02 atoms sulphate of barytes.
6*82 ,, sulphate of strontian.
0.16 ,, sulphate of iron.
Including the sulphate of iron with the sulphate of
strontian, we have for the constitution of this mineral
3 atoms sulphate of barytes.
7 ,, sulphate of strontian.

1835.] Species of Minerals containing Barytes. 375

Sulphate of barytes and strontian are met with combined
in other proportions. I have seen three other species
described, but not having any of them in my cabinet, I have
not had it in my power to subject them to analysis. But
they have been analyzed by Dr Turner, and M. Gruner of
Hanover, and found composed of

atoms, atoms, atoms.
Sulphate of barytes . . 1 - - 2 - - 5
Sulphate of strontian . . 5 - ' - 7, - - 2

Article VI.

On Human Saliva. By C. G. Mitscherlich.
(Poggendorff's Annalen, xxvii. 320.^

A most important object in the analysis of animal secretions
is to obtain them in a pure state. In the case of the saliva
it is obvious that there are numerous difficulties in the way
of procuring that fluid free from the substances which may
accidentally find their way into the mouth, either from the
food after mastication, from the oesophagus, or from the
mucus surfaces. In order to avoid the mixture of foreign
matter which it must necessarily meet with in the mouth,
the best method would be to procure it externally from the
parotid gland, either by means of an artificial incision, or
during the occurrence of a salivary fistula. It was in the
latter way that Mitscherlich obtained the saliva which he
subjected to examination. The saliva flowed out by an
opening half a line in diameter, at the third grinder of the
upper jaw, on the left side, the mouth of the parotid
duct being completely closed up. The patient, who was
about 41 years of age, was not much affected, so far as
regarded his general health, except that some degree of
emaciation was present. Digestion remained regular. The
urine was acid ; the perspiration natural, and the dejections
as usual.

The method hitherto employed to determine the quantity
of saliva secreted by the glands, was to estimate that con-
tained in the mouth, a mode which was liable to great
objections ; but when the saliva of the parotid gland was all
evacuated by an opening in the cheek, the proportion of
the secretion under different circumstances was easily ascer-
tained.

376 C. G. Mitscherlich on [May

Mitscherlich found that the secretion is diminished by
passions of the mind, by perfect rest, and is always increased
by the motion of the lower jaw, and by coughing. During
mastication, and in the act of drinking, the saliva is sepa-
rated in abundance, and often collects in drops. At the
commencement of mastication the saliva was stronger both
in regard to chemical composition and consistence, than
towards the termination. During the night the quantity of
saliva was very small, as might be expected, when the
motions of the under jaw, of the tongue, as well as the
nervous action on the salivary glands are no longer stimu-
lating the secretion.

The quantity collected in an apparatus provided for the
purpose, and properly adjusted, from 8J p.m. to 5 a.m.
amounted to 0*748 grm. (11 J grs.) After breakfast, between
8| and 12 a.m. 1*862 grm. (19*1 grs.) of saliva were obtained.
The same experiment repeated gave in about three hours
1*242 grm. (29*2 grs.) In the course of four hours in the
afternoon, 1*9 gr. were procured, during which period and
that in which the previous experiment was made, the patient
spoke a good deal. During mastication the experiment upon
the quantity of saliva secreted were so often repeated that
Mitscherlich considers the point completely settled.

The smallest quantity procured during three meals was
46 grm. (708* grs.) the greatest quantity 74*5 grm.
(11*47 grs.) but, in addition to these regular repasts, the
patient drank twice daily a cup of tea, when 5 or 6 grms.
(77 grs.) passed through the fistula.

In this individual, therefore, with the usual diet of the
hospital, which consisted of water gruel and wheat bread
to breakfast, broth, beef, pulse, and bread to dinner, and
water gruel and bread in the afternoon, the amount of saliva
excreted in the 24 hours may be reckoned at between 65
and 95 grms. (1001 grs. 1463 grs.)

Mitscherlich endeavoured to ascertain the quantity of
saliva derived from the other salivary glands, and for this
purpose he caused the patient to spit into a glass vessel
during a given time. In 15 minutes the quantity in the
glass was 6*27 grms. (96 J grs.) and that derived from the
fistula 0*92. (14*16 grs.) the insoluble portion of the liquid
from the mouth being separated by filtration. This experi-
ment is not satisfactory, however, because the parotid is

1835.] Human Saliva. 377

the largest gland, and the other five glands yield more than
six times the quantity of fluid secreted by it.

With regard to the effect of different kinds of food in
increasing the quantity of saliva, Mitscherlich found great
difficulty in experimenting with precision, but every one
knows the disparity between soft and hard bodies in pro-
ducing saliva. Mitscherlich estimates the effect of the
former to the latter as 3 to 5.

Chemical nature of Saliva. — The saliva in the mouth acts
upon tests very variously, being generally slightly acid, often
neutral, and sometimes alkaline. The cause seems to be
that the saliva remains in contact with the mucus, which is
separated from the mucus glands in the mouth. The saliva
from the fistula which was exempt from the mixture was
alkaline during mastication, and acid at other periods.
Twice, however, shortly before eating, the saliva was found
to be slightly alkaline, and immediately after eating it was
perceived to be still alkaline, but remained so only for a
short time. When the saliva was drawn into the mouth
by the exertion of the patient it was observed to be slightly
acid. In this case the saliva from the fistula was neutral,
or scarcely acid. The saliva in the mouth often indicated
a free acid, and in the instance where the saliva from the
fistula was acid, the saliva of the mouth was completely
neutral. Mitscherlich was inclined to attribute this to the
chemical combination of the saliva with the mucus, by
which ammonia was extracted.

During eating and drinking the saliva was invariably
alkaline, for after the first mouthful the acid disappeared,
and reddened litmus paper became blue.#

Specific gravity. — Tiedemann and Gmelin found the
density of saliva produced during the smoking of tobacco
1*0043. In Mitscherlich's experiments it varied from
1*0061 to 1-0088, but when collected during the usual
hospital dinner, its specific gravity was almost constant at
1-0074. He found also, that the specific gravity was
greater, in proportion to the cessation from eating.

The density of the saliva in the trials of Tidemann and

* These statements are at variance with those of Dr. Donne, (Ann. de Chim.
lvii. 402.) who affirms, that the saliva is always alkaline in the healthy state, but
that he has found it possessing an acid re-action in diseases of the stomach, espe-
cially in gastritis. — Edit.

378 C. G. Mitscherlich on [May

Gmelin was greatly underrated, because they employed a
fluid which was produced by the stimulus of tobacco smoke,
and was mixed with the secretion of the mucus membrane
of the mouth.

Action of re-agents. — Saliva from the fistula was not
quite clear, for it contained some white flocks, which after
standing for some time sunk to the bottom of the vessel,
and were then separated in greater abundance from the fluid.
This first substance does not appear to belong to the saliva,
but seems to be derived from the mucus membrane of the
parotid gland and duct, as well as from the peculiar
membrane of the fistula. When the saliva is filtered this
substance remains on the filter. 29*797 grms. (458*8 grs.)
of fresh saliva are mixed with 0*0015 grm. (*023 gr.) of the
matter: 24*955 grms. (384*2 grs.) gave in another trial 0*019
grm. (0*29 gr.) This substance is insoluble in water,
alcohol and acids, dissolves in potash, out of which solution
it is precipitated by acids, and has when dried a brown
colour. Its chemical properties seem to indicate, that it is
not chemically combined with the saliva, but mechanically
mixed with that fluid.

The filtered saliva is quite clear ; more or less of a yel-
lowish colour ; not mucilaginous ; alkaline and of the density
already given. After standing for some time, a whitish
mucus like substance separates which is insoluble in water,
alcohol and acids, dissolves easily in potash, and is partly
precipitated out of this solution by acids. This substance
will be noticed in the sequel.

Alcohol produces in pure saliva a white precipitate,
which by heating is partly dissolved, but on cooling again
falls down.

The precipitate with nitrate of silver is easily soluble in
ammonia.

Tincture of galls occasions a clear brown precipitate,
which dissolves by the application of heat, but re-dissolves
when the liquid is allowed to cool.

Acetate of lead forms a copious white precipitate which
does not dissolve by heating, but disappears by an excess
of acetic acid.

Sulphuric acid gives a slight flocky precipitate ; caustic
potash and ammonia produce no visible effect.

Quantitative analysis. — The quantity of free alkali was

1835.] Human Saliva. 379

determined by the addition of sulphuric acid. 29*797 grms.
(458*8 gr.) of saliva of the specific gravity 1*0070 required
for complete neutralization, 0*0925 grm. (*416gr.) sulphuric
acid of the sp. gr. 1*816=0*066 grm. (1*016 gr.) common
sulphuric acid. Hence, 100 parts of saliva take 0*223 grm.
(3.43 gr.) sulphuric acid for saturation, which neutralize
0*174 grm. (2*67 gr.) soda.

In a second trial 59*594 grms. (917*6 gr.) saliva of sp. gr.
1*0074 required 0*163 (2*5 grs.) sulphuric acid of sp. gr.
1-816=0*117 grm. (1*8 gr.) sulphuric acid, or in 190 parts
0*196 sulphuric acid which saturate 0*153 soda.

When the sulphuric acid is added, a white flocky preci-
pitate falls down, which possesses the properties of the
salivary mucus. The first drop of acid produces a muddi-
ness, which *as the point of saturation approaches is in-
creased. Hence, it is probable, that as no carbonic acid
appears to be extricated, the soda exists in combination
with the mucus. This idea seems also to be confirmed by
the circumstance, that when the saliva is exposed to the
air, carbonic acid is absorbed by the alkali and the mucus
is precipitated.

The free alkali is not volatile, for no ammonia was driven
off by heating. To determine the quantity of inorganic bases,
47*7997 grms. (768*4 grs.) of saliva of the sp.gr., 1*0075
were treated with nitric acid till all the organic constituents
were destroyed. The dry residue amounted to 0*338 grm.
(5*2 grs.) which when dissolved in water, left 0*015 grm.
(£ gr.) Muriatic acid dissolved 0*008 grm. (*123 gr.) of
this, which after solution yielded a precipitate with ammo-
nia, consisting of phosphate of lime, equivalent to 0*0168
per cent. The portion which was insoluble in muriatic
acid was examined by the blow-pipe and found to be silica.
That part which dissolved in water amounting to 0*323
grm. (4*97 grs.) was treated with alcohol and chloride of
platinum, and precipitated 0*096 grm. (1*47 gr.) of potash
=0*209 per cent.

The solution filtered from this precipitate was evaporated;
the residue heated to redness and re-dissolved in water.
From which 0*17 grm. (2*6 grs.) chloride of sodium was
obtained =0*188 per cent. soda.

To determine the quantity of chlorine, 22*224 grms.

380 C. G. Mitscherlich on [May

(342-18 grs.) of filtered saliva of sp. gr. 1*0081 were mixed
with an excess of nitric acid, and precipitated by nitrate of
silver. The resulting precipitate amounted to 0*076 grm.
(1*17 grs.) chloride of silver =0*084 grm. (1*29 gr.) per
cent, of chlorine.

The proportion of phosphoric acid is given under phos-
phate of lime.

After the saliva has been treated with nitric acid until
all the organic constituents are destroyed, a residue re-
mains which is partly soluble in water, and affords a trace
of sulphuric acid with muriate of barytes. Saliva contains
therefore, muriatic acid, phosphoric acid, and sulphuric
acid. The potash being the stronger base is united with
the stronger acid, and the free soda being a weaker base,
is combined with its appropriate acid. There remain,
however, 0.094 potash in 100 parts, and 0*024 per cent,
soda to be neutralized by an organic acid. This is lactic
acid, which Mitscherlich has not been able to estimate in
the direct way.

The salts contained in saliva appear to be

Chloride of potassium 0*18 percent.

Potash (combined with lactic acid) . 0*094 ,,

Soda (with lactic acid) . . . . ' . 0*024 ,,

Lactic acid ,,

Soda (probably united to salivary mucus) 0* 164 ,,

Phosphate of lime 0*0174 „

Silica 0-015

Treviranus considered that the dark red colour which is
produced by adding to the saliva muriate of iron, was owing
to the existence, of what he called acid of the blood.
Gmelin ascribed this property to the presence of sulpho-
cyanic acid. A single drop of the solution of muriate of
iron, occasions a dark red colour in a great quantity of
saliva. By agitation the mucus separates, and a fine dark
red colour is exhibited in the saliva. Saliva from the
mouth, gave the same result as the saliva from the fistula,
and was the same both in the acid and alkaline states of
that fluid.

In the examination of the organic constituents, high
temperature is to be avoided, because they are altered by
such means. The evaporation of the water and alcohol is

1835.] Human Saliva. 381

to be conducted under the receiver of an air pump. The
quantity of the fixed constituents of the saliva, varies
slightly in different trials, but is in proportion to the
specific gravity.

Saliva of sp. gr. 1*0072 contains 1*468 per cent, of fixed
matter. 1*0079 „ 1*551

1*0083 „ 1*632

66547 grms. (1024*7 grs.) of filtered saliva of sp. gr.
1*0079 being neutralized with dilute sulphuric acid, yielded
a flocky white precipitate, which when collected and
washed on the filter, weighed 0*061 grms. (*93 grs.) The
liquid which passed through the filter was evaporated
under the receiver of an air pump, and left a residue
amounting to 1*051 grm. (16*17 grs.) 0*543 grm. (8*3 grs.)
of this matter dissolved in alcohol of sp. gr. 0*863, and the
other results after treatment with water and alcohol were,

grm. grs.

Insoluble in water and alcohol 0*212 3*264

Soluble in water, insoluble in alcohol ... 0*357 5*497
Soluble in water, insoluble in absolute alcohol 0*190 2*926
Soluble in water and absolute alcohol . . . 0*340 5*236

1*099 16*923
66*775 grms. (1028J grs.) of saliva of sp. gr. 1*0083 were
without being neutralized, evaporated to dryness by the
air pump and yielded 1*08 grm. (16*6 grs.)

These were analyzed and gave, grms. grs.

Insoluble in water and alcohol (sp. gr. 0*863) 0*281 4*327
Soluble in water and insoluble in alcohol

(sp. gr. 0*863.) 0*352 5*420

Soluble in water and insoluble in alcohol

(sp. gr. 0*800.) 0*296 4*558

Soluble in water and alcohol (sp. gr. 0 800.) 0*192 2*956

1*121 17*261
The portion which is not dissolved either by water or

alcohol is salivary mucus. Acetic acid swells it up, but

does not dissolve any of it either in the cold or by boiling.

Sulphuric acid gives it a red tinge, but causes no other

change.

Hydro-chloric acid, without heat after a long time, but

speedily by boiling, produces a blue solution.

382 C. G. Mitscherlich on [May

Ammonia acts like acetic acid. Caustic potash produces
an imperfect solution.

The matter soluble in water but insoluble in alcohol
(sp. gr. 0*863) is called by Berzelius salivary matter.
Gmelin made many experiments upon this substance, which
differ considerably from those of the Swedish chemist.
The salivary matter in neutralized saliva, acts strongly
acid upon test paper, but without neutralization, red lit-
mus paper becomes blue in the solution. It is of a yel-
lowish brown colour, but when the alkali is not saturated,
and it is kept from the moisture of the atmosphere, the
colour is white. The yellowish brown salivary matter dis-
solves in water, and when carefully evaporated does not
re-dissolve, but always leaves a trace of an insoluble sub-
stance. The white salivary matter, on the contrary, re-dis-
solves completely in water after evaporation to dryness.
Alcohol occasions a white precipitation which is dissolved
by water.

By the application of a strong heat carbonate of ammonia
is driven off, and the carbonaceous matter contains potash
and soda. No effect is produced upon the aqueous solution
of salivary matter by sulphuric, nitric, or hydro-chloric
acids, or by ammonia or caustic potash. The same is the
case with corrosive sublimate and muriate of iron. Nitrate
of silver gives a white precipitate which is re-dissolved by
ammonia.

If the salivary matter is obtained without neutralizing
the free alkali, then acetate of lead affords a copious white
precipitate which does not dissolve by boiling, becomes a
slight muddiness by the addition of water, and wholly dis-
appears by an excess of acetic acid. If the saliva is pre-
viously neutralized by sulphuric acid, the salivary matter
contains sulphuric acid salts, and when the sulphuric acid
is removed exhibits the characters already mentioned.

Infusion of galls does not alter the solution of salivary
matter.

The matter soluble in water and insoluble in absolute
alcohol is no longer soluble in alcohol of sp. gr. 0*863, and
consists principally of salts with some animal matter of a
yellowish colour. The solution of this substance is not
affected by muriate of barytes, corrosive sublimate, muriate
of iron, sulphuric acid, muriatic acid, nor by infusion of galls.

1835.] Human Saliva. 383

Acetate of lead forms a white precipitate which does not
disappear on the addition of water, and is not dissolved by
acetic acid.

Nitrate of silver produces a precipitate readily soluble in
ammonia.

By exposure to a strong heat it affords the product of ani-
mal matter, and a carbonaceous substance is left containing
potash and soda. It follows, from these experiments, that
the substance is identical with the salivary matter, and be-
comes soluble in alcohol of 0*863, by combining with
extractive matter.

The substance soluble in water and absolute alcohol has
a yellowish red colour; affords by calcination the same
products as other animal substances, and leaves a salt which
dissolves in dilute muriatic acid. This salt, when treated
with chloride of platinum and absolute alcohol, partly
precipitates and partly dissolves, affording in the usual way
potash and soda. The properties of this substance can be
best observed when the saliva has been neutralized with
sulphuric acid, as the extract then contains no dissolved
salt. As much water is now to be added as is requisite for
the solution of the animal matter, when the crystallized
salt dissolves first. The liquid is then decanted from the
crystallized salt, and on the addition of muriate of barytes
no sulphuric acid can be detected.

This liquid animal substance readily soluble in alcohol
and water has a red colour; possesses an acid reaction
without containing sulphuric acid, (perhaps lactic acid,
which may be obtained in a free state by the addition of
sulphuric acid,) and produces no precipitate with acids,
potash, ammonia and corrosive sublimate. Acetate of lead
produces a considerable white precipitate which dissolves
by boiling. Muriate of iron affords a flocky reddish preci-
tate, which does not re-dissolve by adding water.

A precipitation proceeds from the addition of nitrate
of silver, which completely disappears by the action of
ammonia.

The results of the preceding experiments may be summed
up as follows :

1. The separation of the saliva ceases when the muscles
and tongue are motionless, and by the absence of the usual
nervous stimulus.

384 Analyses of Boohs. [May

2. The quantity secreted depends upon the degree and
nature of the nervous stimulus.

3. The secretive organs are excited by the mechanical
action of the mouth.

4. The quantity of saliva which is separated from the
glands during eating and drinking is very great, and in-
creases with the hardness of the food.

5. From the parotid in the 24 hours from 65 to 95 grms.
or from 2 oz. 6 drs to 3 oz. troy, of saliva are separated.

6. Saliva from the mouth proceeding from five glands
amounts to six times the quantity from the parotid. The
saliva of the mouth, however, contains a considerable
quantity of mucus.

7. The saliva during the excitement of mastication or
drinking is alkaline, at other times acid.

8. The specific gravity varies from 1*0061 to 1*0088.
The causes which occasion these changes are not yet
ascertained.

9. The results of analysis are similiar to those of Gmelin
and Berzelius, who found it to consist of salts and organic
matter.

10. The organic constituents are salivary mucus ; a peculiar
salivary matter, with the characters which Berzelius has
described and extractive matter; a substance soluble in
alcohol of thesp.gr. 0*863, when the portion soluble in
absolute alcohol remains mixed with it, but insoluble, and
possessing the characters of salivary matter after that con-
stituent has been removed.

Article VII.

ANALYSES OF BOOKS.

The Transactions of the Linnean Society of London.
Vol. xvii. Part I. 1834.

Contents. — I. Description of the organs of voice in a new
species of wild swan (Cygnus Buccinator Richardson.) By W.
Yarrell, Esq., F. L. S., &c.

II. Description of three British species of fresh water fishes be-
longing'to the genus Lenciscus of Klein, by W. Yarrell, Esq.,
F. L. S., &c.

III. Observations on the Tropaeolum pentaphyllum of Lamarck,
by Mr. David Don.

1835.J Transactions of the Linnean Society of London. 385

IV. On the adaptation of the structure of the Sloths to their
peculiar mode of life, by Professor Buckland.

V. Observations on Naticina and Dentalium two genera of
Molluscous animals, by the Rev. Lansdown Guilding.

VI. Monograph of the East Indian Solaneae, by C. G. Nees
Esenbeck, M. D.

VII. On the Lycium of Dioscorides, by J. Forbes Royle, F. L. S.

VIII. A review of the natural order Myrsineae, by M. A. De
Candolle.

IX. On the Modifications of Aestivation observable in certain
plants formerly referred to the genus Cinchona. By Mr. D. Don.

X. Additional Observations on the Tropaeolum pentaphyllum.
By Mr. D. Don.

All these papers, with the exception of the two last, amounting to
six pages, were read before the Linnean Society in 1832. The
quality, however, of the materials of which this volume is composed
does not produce the same disappointment which is experienced in
reference to the quantity. We may refer more particularly to
Esenbeck's Monograph, and the distinguished De Candolle's review,
for the materials of both of which we are indebted to the industry of
Dr. Wallick and the munificence of the East India Company. It is
remarkable, however, that of 145 pages, of which the volume con-
sists, 90 are written by foreigners. I conceive that a short outline
of these papers will be highly acceptable to those who may not have
an opportunity of reading the transactions themselves.

The paper of Esenbeck treats of two natural orders, viz. Solaneae
and Verbascinae, in reference to Indian species : —

SOLANEAE.

I.SOLANUM.
16. S

i. Maurella.
A Pedicles equal to the common
peduncle.

1. S Fistulosum.

2. S Incertum syn nigrum.

B Pedicles of the fruit, shorter
than the common peduncle.
S Rubrum.

2. Geminifolia

3.

4.
5.

S Spirale.

S membranaceum,

6.

S laeve.

7.

S denticulatum.

a

S bigeminatum.

9.

S Neesianum.

10.

n.

S crassipetalum.
S decemfidum.

12.

S macrodon.

13.
14.

S lysimachioides.

3. Verbascifolia.
S verbascifolium.

15.

S auriculatum.

giganteum.
17. S vagum.

4. Melongena.
melongena.
heteracanthum.
5. Torva, (acute lobed
leaves.)
Wightii.
barbisetum.
ferox.
torvum.
Indicum.
jacquini.
procumbens.
sarmentosum.
trilobatum.

6. Nycterium.

29. S (nycterium) pubescens.

7. Pinnatifolia.
tuberosum.

18.
19.

20.
21.
22.
23.
24
25.
26.
27.
28.

30.
31.

S

S calycinum.

VOL. I.

2c

386

Atiali/ses of Books.

[May

20. Has been named in honour of the indefatigable Dr. Wight of
Madras, who for some time has employed painters and collectors
at his own expense, for the purpose of elucidating the botany of
Madras.

25. Under this species Esenbeck includes the S diffuxum of
Roxburgh. It is an abundant plant in Madras and Bengal, and I
have found it occurring plentifully in the neighbourhood of Bombay.

30. This merely refers to the potatoe as cultivated in Madras and
Bengal. It does not attain any considerable size in the hot parts
of these presidencies, but near Bussorah I believe it thrives much
better.

II. LYCOPERSICUM

] . L esculentum.

Dun.
2. L Humboldtii.

in. capsicum Linn.

1. C grossum. 3. C frutescens, the Tschili or Chili.

2. C fastigiatum. 4. C chamaecerasus.

1. P somnifera

2. P Peruviana.

iv. physalis Linn.

3. P puoescens.

4. P minima.

5. P angulata.

6. P Indica.

1. D alba

2. D fastuosa.

v. anisodus Lin.
Luridus.

vi. datura Linn.

3. D trapezia.

4. D ferox.

D stramonium.
D tatula.

VII. NICOTIANA.

N tabacum. Hab. near Katmandoo.

VIII. HYOSCYAMUS.

H Niger. Hab. near Futteghur, Moradabad, Delhi.

VERBASCINAE.

I. verbascum thapsus. Hab. near Gossain Than in Nepaul.

2. V Indicum. 3. V spec. dub.

II. celsia coromandelina. 2. C Viscosa.

III. isanthera permollis.

The paper of De Candolle does not require such a minute analysis
as the species of the order Myrsineae, which he has therein illus-
trated, are all natives of foreign climates, and cannot, therefore, be
so generally interesting as those of the order of Solanece. A few
facts may, however, be stated, which exhibit in a striking point of
view the rapid progress which botany is at present making in regard
the discovery of new species.

The order Myrsineae is now placed between the orders Sapoteae
and Primulaceae, from the latter of which it seems to differ in the
indehiscence of its fruit, and from the former by the constant defici-
ency of stamens alternating with the lobes of the corolla. This order

1835.] Transactions of the Linnean Society of London. 387

is divided by the author into three tribes, 1. Aegicereae, with an
erect embryo ; 2. Ardisiae, including the bulk of true Myrsineae ;
3. Moeseae, with an inferior ovarium, approaching to primulaceae.

He has proposed two new genera, Weigeltia and Conomorpha,
and a third, Choripetalum, which has not been sufficiently examined.
The species of this order produce a resinous substance, which appears
in the form of dots or reservoirs, in different parts of the plant,
chiefly on the leaves, flowers, and berries, and also in the hard wood
of the Myrsine and Aegiceras. It melts and burns in the flame of a
candle, is not soluble in water, but is so in oil or alcohol when mode-
rately heated, giving to the latter a rose colour, These facts were
particularly observed in the berries of the M. semiserrata. The
dots are dark or light brown, reddish or yellow, varying in size,
shape and position, in different species. The fruit of Embelia
ribes possesses a styptic taste, which the author supposes to depend
on this resinous substance.

Of 180 species of myrsineae 58 are described for the first time
by the author. They grow commonly on the hilly and mountainous
regions of the hottest parts of the globe. None have yet been found
beyond the 39th or 40th degree of latitude, viz. in Japan, whilst
they abound in Java and in some parts of India and South America.
No species is known in Africa except at the Cape and at the Canary
Islands, Mauritius, Bourbon and Madagascar. The 180 species are
distributed as follows : 112 in Asia and New Holland, 48 in America,
and 20 in Africa.

Mr Don, in his paper, shews that the form of aestivation of the
corolla is of great importance as a character to distinguish different
families, especially among the monopetalous orders, except in the
order Rubiaceae, where examples of every kind of modification
occur. In the Cinchona grandi flora and rosea it is imbricate, in
C lanceolata and the rest of the true cinchonae it is valvate, while
in the West Indian species it is induplicate and in the C exelsa
plaited. Of the genus cinchona he enumerates seventeen true species.
2. Combuena, (C grandiflora) two species ; obtusifolia and acumi-
nati ; 3. Lasionema ( C rosea) roseum ; 4. Exostema, seven species ;
5. Hymenodictyon (C excelsa) exelsum and thyrsiflorum ; 6. Lu-
culia gratissima and cuneifolia ; % Pinckneya pubens.

The other paper of Mr. Don is upon the Tropaeolum penta-
phyllum of Lamarck, which has been introduced into this country
by Mr. Neill of Edinburgh. He shews that it differs from the genus
Tropaeolum in having the aestivation of its calyx valvate, that of
Tropaeolum being imbricate. In the nature of its fruit, which is a
black juicy berry resembling the Zante grape, and in the reduced
number of its petals. He has formed it into a new genus, and
terms it Chymocarpus pentaphyllus. Its calyx is persistent, while
that of Tropaeolum is deciduous. The embryo is small and white,
contained in a thin cartilaginous testa, and the cotyledons round and
compressed. It belongs to the natural order Tropaeoleae, and is a
native of the sandy plains of Buenos Ayres. It was first observed by
Commerson, and afterwards by Tweedie.

2c2

388 Analyses of Boohs. [May

Mr. Royle has endeavoured to identify the plant termed Lj/cium
by Dioscorides. The hjcium of Asia Minor he considers may be
made from the Rhamnus infectorius, or different species of Rham-
nus, or the Berberis vulgaris. The hjcium of India, again, he
identifies wiih the produce of the Berberis aristata, occurring on
Choor mountain, 5000 to 8000 feet high, called in Arabic, Ambur-
barees, in Persian Zirishk, the Wood darkhuld and darchob, the ex-
tract hooziz, the hill name being chitrach, and also with the extract
obtained from the B li/cium growing at Mussooree, 3000 to 5000 feet
of elevation, called Kushmul, the extract rusot.

This rusot can be procured in every bazar in India, and is used
by the native practitioners in chronic and acute inflammations of the
eye, both simply and combined with alum and opium. It was
employed by Mr. M'Dowell in the Egyptian ophthalmia, and Mr.
Royle has applied it with beneficial effects in cases succeeding acute
inflammation. The extract is rubbed to a proper consistence with a
little water, sometimes with opium and alum and is then applied in
a thick layer over the swollen eyelids. The addition of a little oil
renders the preparation less desiccative.

It is mentioned in the Mukhzun-ool-udwieh, (store house for
medicines) under the name of loofuon, which is obviously the same
as look / on of the Greeks. Dioscorides describes it as being formed
from a shrub called Lonchitis, which is thorny, and has branches
three or more cubits in length, whose bark, when bruised, becomes
of a reddish colour and whose leaves resemble those of the olive.
In tl^ese respects Mr. Royle's plant agrees with that of Dioscorides.
Indeed we have rarely seen a more plausible deduction from etymo-
logy than is exhibited in the present instance. It is to be regretted,
however, that the rusot has not yet found its way into chemical
hands.

Comparative Anatomy, 8fc.

Mr. Yarrell describes the organs of voice in the Cygnus bucci-
natur, a new species of swan, figured by Dr. Richardson, from the
interior of the fur countries of North America. This species, which
is called the Trumpeter, furnishes the largest portion of the supply
of swan skins imported by the Hudson's Bay Company. Its beak is
black ; its trachea is made up of narrow bony rings and small inter-
vening membranous spaces as far as the first convolution within the
sternum ; but the returning portion of the tube, forming a second
convolution, is composed of broader and stronger bony rings, with
wider intervals. The course of the trachea within the sternum
differs from that of the hooper, for after descending by the neck it
passes backwards within the keel, and between the two plates of the
back bone to the depth of six inches, then curving horizontally and
slightly inclining upwards, returns at first by the side of and after-
wards over the first inserted portion near two thirds of the whole
distance. A second curve of this returning portion is then suddenly
elevated two inches above the line of the superior surface of the keel,
and traverses the interior of a hollow circular protuberance on the
dorsal surface of the sternum itself. The usual ascending curve of

1835.] Transactions of the Linnean Society of London. 389

the trachea then takes place, by which the tube, ultimately receding,
gains the interior cavity of the breast. The bronchiae are two inches
long. Such are the peculiarities which characterize this new species.

Two species of Leucisous, or dace family of fish, are described by
Mr. Yarrell, one of which, L. Lancastriensis, was merely noticed
by Mr. Pennant as likely to be new under the name of Graining. It
is more slender than the dace. In the latter the length is to the depth
as 4 to 1, but in the graining as 5 to 1. The head and back are of a
pale drab colour, tinged with red ; irides, yellowish-white ; the fins
pale yellowish-white. In the dace the back and sides yellowish
olive-coloured, tinged with blue ; lower fins pale red, with a smaller
number of fin rays in some fins, in others less. It occurs in a stream
which rises in Knowsly Park, in the Mersey and in the Alt. L.
elongatus, pinna dorsali supra pinnas ventrales posita, caudali profunde
biloba, capitis lateribus supra subparallelis ore parvo, dorso lateri-
busque superne subrufescenti, isabellinis inferne ventreque argenteis.

The other species, L coerulevs is quite new. He gives it the
English name of Azurine. Its depth is to its length as 7 to 2,
resembling the red eye in shape, but is easily distinguished from that
species by the silvery whiteness of the abdomen, which in the red
eye is of a brilliant golden orange, and also by its white fins, which
in the other are vermilion. L ovato-lanceolatus, pinna dorsali pone
pinnas ventrales posita, dorso plumbeo, ventre argenteo, pinnis albis.
B3D 10 P 16 V9 A 12 C 19.

Mr. Guilding observes that the Naticidae form a very distinct
family from the Neritidae. The former are apparently blind, the
operculum has no appendages; their useless tentacula are weak and
turned back on the shell, while in the act of creeping the head and
its organs are perfectly veiled by a broad expanded hood, the sensible
contractile apex of which serves to guide its motions. At first sight
they rather resemble the Bullidae.

He describes and figures two species of Dentalium, viz. D Semi-
strioiatum, and D Sowerbyi. Very little is known with regard to
this genus. M. Deshayes had previously thrown some light on its
history, but its position in the natural system is not yet made out.
Mr. Guilding is inclined to place it near patellae. It resembles in
its vent the genus fissurella, in its apical fissure the posterior
marginal rima of emarginula.

Dr. Buckland, in that spirit of benevolence with which the writ-
ings of naturalists are almost universally inspired, reproves the harsh
sentence which has been passed on the sloth by Cuvier and strives
to show that this vulgar type of indolence is undeserving the impu-
tation of feebleness or imperfection, and still more of the charge of
monstrosity ; that it affords a striking example of perfect mechanism
and contrivance when viewed in reference to the office it is destined
to fulfil, f< the animal being fitted to its state."

Cuvier has stated that we find in sloths such few relations to
ordinary animals that the general laws of existing organizations

390 Analyses of Books. [May

supply so little to them, and the different parts of their body seem
so much at varience with the laws of co-existence which we find
established throughout the rest of the animal kingdom, that we
might really believe them to be the remains of another order of
things, the living relics of that preceding state of nature whose ruins
we are obliged to search for in the interior of the earth, and that
they have by some miracle escaped the catastrophe which destroyed
the other species which were their contemporaries. The skeleton of
the Bradypus tridactylus, or Ai, says Cuvier, affords proportions
extremely anomalous, and apparently defective ; the arms and fore-
arms taken together are almost double the length of the thigh and
leg, so that when the animal goes on all fours he is obliged to drag
himself upon his elbows, and if he attempted to stand erect upon his
hind feet the entire fore foot would still rest upon the ground ; but
the Ai never can stand upright, because his hind feet are so ill
articulated for walking that they are unable to support the body in
such a position ; the pelvis is also so broad, and its cotaloid cavities so
set back that the thighs are kept at a distance, strutting outwards,
and the knees can never approach one another. The length of the
fore legs embarrasses the animal in its attempts to walk, and its
forward movements on the ground are made by fixing its claws on
an object and then dragging its body up to it. This is the unfavour-
able side of the subject. Dr. Buckland views it in a benevolent
light. The extraordinary length of the arm, and fore arm, so
inconvenient for moving on the earth, are of essential and obvious
utility to a creature whose body is of too great weight to allow it to
crawl to the extremity of the branches to collect the extreme buds
and youngest leaves which form its food ; these long arms, in fact,
perform the office of the instrument called u lazy tongs," whereby
the creature brings food to the mouth from a distant point without
any movement of the trunk. The structure of the arm fixed to the
shoulder by an universal joint admitting of rotation, and having at
the elbow two kinds of articulations which allow pronation and
supination, gives to the hand a power of moving in every possible
direction. The breadth of the pelvis and outward position of the
thigh bones, which are also broad and flat, the distance of the knees
from one another, and curvature of the bones of the leg, admirably
adapt these extremities of the animal to the purpose of clasping, and,
as it were, riding upon the trunks and branches of trees : A peculiar
condition of life was to be provided for, viz. that of a quadruped
which was to feed, to sleep, and in short, to dwell entirely upon
trees, for the succulent nature of its food renders it necessary to
descend to drink ; and if we look at the anomalous extremities of this
animal with a view to their use as instruments of continual suspen-
sion upon trunks and branches, the hind legs performing the double
office of adhesion and progression, and the fore legs the quadruple
function of adhesion, progression, prehension and defence, we shall
find each article of deviation from ordinary structure adapted to some
useful function in its peculiar economy, we shall find a new system
of machinery contrived and set together as it were on a new plan,
from old materials, (as machines of different functions may be com-
pounded from similar wheels, every motion having relation to some

1 835 . ] Transactions of the Linnean Society of London . 39 1

well defined and useful end) and the result of these deviations pre-
senting an animal structure not less perfect, in reference to its state,
than those slender and graceful forms of light and active quadrupeds
with which we usually, and perhaps more justly, associate our ideas
of perfect symmetry and beauty.

The stiffness of the toes and fingers of this animal, which fit it for
the habit of constantly living and feeding upon trees ; and the diffi-
culty of motion in other joints become advantageous and a source of
strength to an animal living as it does, while to one moving on the
ground, they would be a source of great inconvenience. The claws
of the Sloth are of unusual length, and so powerful that they are
capable of strangling a dog, holding him at arm's length. On trees
the Sloth is surprisingly tenacious of its hold. Mr. Burchell has seen
the limbs, even just after death, continue fast clinging round the
object to which they were adhering before the animal expired. All
mammalia, from the Giraffe and Camel down to the Cetacea, have
, invariably seven cervical vertetrse, while the Sloth was considered to
have nine. Mr. T. Bell has, however, shewn that the two lowest
are really dorsal, but their position so far in advance of the clavicle
and scapula, enables them to co-operate with the seven true cervical
vertebrae, in increasing the rotatory motion and flexibility of the neck.
Hence, the animal has the power of looking backward over its own
shoulder. Mr. Burchell has observed, that this animal can turn
its head quite round, and stare a person in the face who is directly
in its rear, while at the same time the body and limbs are unmoved.
He also noticed, that his captive Sloths assumed during sleep, a
position of perfect ease and safety on the fork of a tree ; their arms
embracing the trunk, their backs resting in the angle of a branch,
and their heads reclining on their own bosom, the animal being thus
rolled up nearly in the form of a ball, with the vertebral column bent
circular. The Sloth has no incisor teeth, because the leaves are
brought to the mouth, being collected from the branches by the
powerful claws.

Besides the four canine teeth, there are on each side four molars
in the upper and three in the lower jaw. The construction of these
teeth is the most simple that exists ; they are .composed of a cylinder
of bone encased with enamel and hollow at the two extremities, the
upper cavity being produced by the act of mastication, which wears
away the softer bony texture of the interior more readily than the
exterior enamel, and the lower cavity being filled with gelatinous
pulp which maintains the continual growth of the tooth, these simple
teeth being employed exclusively in the mastication of buds and
leaves are fully adequate to the wants of an animal which has no
need of more complicated teeth. Mr. Waterton states, that he " in
crossing the Esquibo one day, saw a large two-toed sloth on the
ground upon the bank, though the trees were not twenty yards from
him, he could not make his way through the sand time enough to
make his escape before we landed, he threw himself on his back and
defended himself with his fore legs. I took a long stick and held it
for him to hook on, and then conveyed him to a high and stately
mora, he ascended with wonderful rapidity, and in about a minute he
was almost at the top of the tree ; he now went off in a side direc-

392 Analyses of Books. [May

tion and caught hold of the brancli of a neighbouring tree, he then
proceeded towards the heart of the forest."

When resident at Para, near the mouth of the Amazons, Mr.
Burchell kept two full grown Sloths and a young one of a three-
toed species, in a garden enclosed with strong stockades ; they were
kept tied up to the pillars of a verandah to prevent their escape ;
against these pillars they always placed themselves in an erect posi-
tion, embracing the pillar with all four legs ; when not tied to the
verandah they got up into trees in the garden ; they slept both day
and night, always fixing their arms round something or other ; their
food consisting of branches was brought to them in the verandah ; they
appeared extremely stupid, and would never come to the food ; they
would eat no leaves but those of the Ceerypia.

None of these animals were ever seen to dfink. The full-grown
ones were never heard to utter any sound, but the young one occa-
sionally (though rarely) gave a short cry or whistling squeak of a
single note. They shewed no indication of fear and seemed to give
attention only with their eyes. They took no notice of the boy that
carried them often across the garden to their place in the verandah with
their long arms sprawling — the only objects of their regard were trees
— they fight on their backs and grapple their enemy to strangulation.
The use of the long wool that covers the body and even the face, seems
to guard them from the annoyance of insects.

Much as we admire the feeling which has dictated the criticism
of Dr. Buckland, we cannot help remarking, that the observations
which he has collected, although they tend to shew that the animal
is fitted to its state, confirm the suspicion that that state is a wretched
one, and bears few relations to that of ordinary, animals.

II. — Facts, Laws, and Phenomena of Natural Philosophy, 6fc.
Translated from the French of Professor Quetelet of
Brussels. With Notes by Robert Wallace. Glas-
gow, 1835, 12mo.

For this translation we are indebted to the industry of some young
ladies in the vicinity of Glasgow. Mr. Wallace the editor states, that
having been called to give lessons to some young ladies who were de-
sirous of acquiring a knowledge of Natural Philosophy, he proposed
that they should employ M. Quetelet's work as a text-book. This
proposal was adopted, the work translated, and the result of their
labours is now presented to the public. It is extremely gratifying to
see the tender sex not only enriching our books of science with their
pencils, but actually studying something more than mere superficialities.
M. Quetelet is concise in his statement of facts, of which the work
forms a good digest. The translation appears well executed, with
the exception, that the English proper names are in general not
translated. The recent important discoveries in electricity by Dr.
Faraday have entirely escaped the notice of the author, but should
have been introduced by the editor, as they include some very curious
phenomena and constitute a very essential part of the science. This,

1835.] Berwickshire Naturalists Club. 393

of course, will be attended to in another editioji, which from the
value of the publication, as an elementary book, may be required.

Ill . — Procceedings of the Berwickshire Naturalists' Club, p . 64 .

The Club whose proceedings are now before us was instituted in
1831, for the purpose of examining the natural history and antiqui-
ties of the county and its vicinity. The members meet in different
parts of the district, tive times within the year, and after making an
excursion in the neighbourhood of the place of meeting, accounts are
given of the discoveries which have been made in the different
branches of science, during the interval, from the preceding meeting.
The object of this association has been well described by Dr. Johnston,
its first president, anAtfte author of the Flora of Berwick. * It
affords," says he, " a point of rendezvous for the naturalists of the
district, where they may cultivate a mutual acquaintance ; where
.they may talk over their common pursuits and all its incidents ; where
they may mutually give and receive oral information ; where each
may nourish his neighbour's zeal ; where we may have our ' careless
season ' and enjoy f perfect gladsomeness/ "

That its establishment has not been in vain, is proved by the facts,
that several new zoophytes have been discovered by Dr. Johnston,
viz. Plumularia Catharina, Fleminea muricata, &c. While a
new plant the Tragopogon major has been added to the British
flora, and new habitats detected of some of the rarest plants, by
members of the club.

The first number of the transactions contains the addresses of the
two presidents, -Dr. Johnston and Mr. Baird on retiring from the
chair, in which they 'give a succinct account of the proceedings of the
association. In Dr. Johnston's address, a fact is mentioned in reference
to plants, similar to what has been subsequently noticed by Dr.
Johnson of Shrewsbury. The former gentleman says, " During our
excursion to Cheviot, it was accidently observed that where speci-
mens of the butterwort ( Pinguicula vulgaris) were somewhat
rudely pulled up, the flower stalk previously erect, almost imme-
diately began to bend itself backwards, and formed a more or less
perfect segment of a circle, and so also if a specimen is placed in the
botanic box, you will in a short time find that the leaves haye curled
themselves backwards, and now conceal the root by their revolution.
Now, the butterwort is a very common plant, yet I am not aware,
that this fact of its irritability has ever been mentioned."

This fact, * and those which Dr. Johnson has brought forward
are interesting, but can only be considered as an extension of our
knowledge of that principle of irritability which is so remarkable
in many plants.

The second number begins with the address of Mr. Selby, the
author of Illustrations of British Ornithology, in which the proceed-
ings of the club during 1834 are detailed. The same gentleman
mentions that he had succeeded in capturing the Macroglossa
stellatarum or humming bird moth, one of our rarest insects, in his
garden at Twizell House.

In a notice of facts relating to the Tormcntilla officinalis, by the

* Phil. Mag. vi. 164.

394 Analyses of Books. [May

editor of this journal, it is stated, that of 3700 specimens of flowers
examined by him, 3628 had all the characters of Tormentilla, 43
possessed those of Potentilla, while the remaining 29 varied in the
number and proportion of the divisions of the calyx and corolla.
From whjch it would appear, that the genus Tormentilla, as was
maintained by the accurate Sir James Smith, does exist, and that
the occasional multiplicity of petals and sepals is to be referred to
luxuriance of growth.

Mr. W. Baird iu a notice of the aurora borealis mentions, that on
one occasion, when this phenomenon was remarkably vivid, he thought
he heard a momentary sound resembling the noise produced by the
quick flight of a bird over head.

Dr. Johnston describes and figures three Roman urns of coarse
clay, which were dug up near Berwick. He considers them ^to
possess all the interest attached to antiquities of 1400 years existence.

This number terminates with a list of additions to the Flora of
Berwick, which have been made since the publication of Dr. John-
ston's Flora.

We would heartily recommend to naturalists in provincial parts
of the country, the establishment of societies like the club of Berwick-
shire, because we are convinced, that they will tend to nourish that
scientific spirit, which for want of due encouragement is too often
blasted'in the bud.

IV. — Abstract of a Paper on the Refraction and Polarization
of Heat. By Professor Forbes. (Read before the
Royal Society of Edinburgh on 29th January 1835.)

The First Section of this paper contains an account of a variety of
experiments undertaken with the thermo-multiplier of Nobili and
Melloni, the instrument exclusively employed in the subsequent re-
searches. By a comparison of its sensibility with that of air ther-
mometers, the author concludes that one degree of deviation of the
needle of the multiplier corresponds to an effect indicated by about
one-fiftieth of a centigrade degree on the others. Without increas-
ing the dimensions of the multiplier, by which its sensibility would
be impaired, he has been enabled, by an optical contrivance, readily
to measure one-tenth of one of its degrees, corresponding to one-five
hundredth of a centigrade degree. From an experiment intended
to detect the heat of the lunar rays, concentrated by a polyzonal lens,
thirty-two inches in diameter, and acting upon this instrument, he
concludes that the direct effect of the moon upon an air-thermometer
probably does not amount to one-three ^hundredth thousandth part
of a centigrade degree.

After mentioning his repetition of M. Melloni's experiments upon
the refraction of heat, the author proceeds, in the Second Section, to
give an account of his own researches on the action of tourmaline on
heat. At first he found (as it afterwards appeared M. Melloni had
done) that no more heat was stopped when the tourmaline plates
had their axes crossed, or transmitted least light, than when they
were parallel, or transmitted most. He afterwards detected a fal-

1835.] Refraction and Polarization of Heat. 395

lacy in his mode of operation, and proved the polarization of heat,
whether luminous or obscure, by tourmaline.

The Third Section treats of the polarization of heat by refraction
and reflection. The former method the author found by far the most
convenient, employing thin plates of mica, arranged at the polarizing
angle, and through which even dark heat was very freely transmitted.
The results were so marked that they were verified in a great va-
riety of ways, and with heat from sources extremely different, as that
of an argand lamp, and water below 200" Fahr. The polarization
of non-luminous heat by reflection was also established, though with
much less ease and simplicity. In this form it was announced by
Berard about twenty years ago, but hitherto his experiment does not
appear to have been repeated with success.

The Fourth Section considers the modifications which polarized
heat undergoes by the action of doubly refracting crystals. The ana-
logies here are derived entirely from those of light. Very numerous
experiments are quoted to shew that the effects are quite analogous,
even when the source of heat is water under the boiling point. The
doubly refracting substance used to depolarize was generally mica.
Out of 157 recorded experiments on depolarization, with three dif-
ferent mica plates, only one gave a neutral and one a negative result.
Yet of these 157 experiments, no less than 92 were made with heat
unaccompanied by any visible light. One very striking experiment
is quoted in illustration of the marked nature of the effects. When
the polarizing and analyzing plates were situated so as to transmit
least heat to the pile, and a thin film of mica was interposed between
the plates in such a position as would depolarize light under similar
circumstances, the film was found to stop more heat than it depola-
rized, or the needle moved towards zero ; but if a mica film much
thicker (so much thicker as to stop more than twice as much com-
mon heat as the first) was similarly placed, that film depolarized
more than it stopped, and the needle moved in the opposite direction
to the former one. The investigation of the laws of depolarization
given in this section are hardly capable of abridgment.

The following are the general conclusions : — *

1. Heat, whether luminous or obscure, is capable of Polarization
by Tourmaline.

2. It may be polarized by Refraction.

3. It may be polarized by Reflection.

4. It may be depolarized by Doubly Refracting Crystals. Hence —

5. It is capable of double refraction and the two rays are pola-
rized. When suitably modified, these rays are capable of interfering
like those of light.

6. The characteristic law of polarization in the case of light holds
in that of heat; viz., that the intensities in rectangular positions of
the polarizing and analyzing plates are complementary to each other.

7. As a necessary consequence of the above, confirmed by experi-
ment, heat is susceptible of circular and elliptic polarization.

8. The undulations of obscure heat are probably longer than those of
light. A method is pointed out of deducing their length numerically.

* These conclusions were stated nearly in these words (except the 6th) to the
Royal Society on the 5th January.

396 Scientific Intelligence. [May

Article IX.

SCIENTIFIC INTELLIGENCE.,

Royal Institution — 27th February.

I. — Floor Cloth Manufactory. — Mr. Brande gave a description
of this manufacture, and added greatly to its interest by going through
the various steps of the process, with the assistance of some workmen
employed in the manufactory at Knightsbridge. The main part
of the manipulation is similar to calico-printing, the figures on the
blocks being upon a much larger scale, and the cloths which are
printed being of an infinitely greater size. The common dimensions
of a floor cloth are 210 or 220 square yards, and hence the immense
size and often unseemly appearance of floor cloth works. A stout
canvass is chosen in the first instance. This is nailed to one ex-
tremity of a wooden frame, and stretched by means of hooks which
are attached to the other sides. It is then washed with a weak
size and rubbed over with pumice stone. No other substance has
yet been found which answers the purpose so well as this mineral.
The next step is that of laying on the colour, which is performed by
placing dabs of paint over the canvass with a brush, and then rub-
bing or polishing it with a long peculiar shaped trowel. Four
coats of paint are thus applied in front and three on the back of
the cloth. To remof e it from the frame when these processes are
finished, a roller on a carriage is employed, upon which it is rolled
and conveyed to the extremity of the manufactory for the purpose of
being printed.

It is then gradually transferred from the roller and passed over
a table which is 30 feet long and 4 feet wide, made of planks placed
vertically, and as it proceeds over the table, the blocks, dipped in
the appropriate colours, are applied. The colours used are ochre,
umber, vermilion, and different kinds of chrome, mixed up with
lintseed oil and a little turpentine.

The number of blocks applied to one pattern depends upon the
number of colours.

The first mode of applying the patterns was by stencils, that is,
the pattern was, cut out in paper, and when the paper thus prepared
was applied to the cloth to be painted, that portion where the ground
was exposed by the interstice in the paper was traversed by a brush.
Then a combination of stencilling and printing was had recourse to,
the former process being first made use of, and then a block was
applied, the stencilling forming the groundwork. Stencilling is
now abandoned. In printing, it is necessary that the cloth should
first be rubbed over with a brush, else the colours will not adhere.
Whether the effect is electrical or not has not been ascertained.
Every square yard of good oil cloth weighs 3^ or 4 J lbs. each gain-
ing by the application of the paint 3 or 4 lbs. weight, and hence, the
quality of this manufacture is judged of by the weight. Whiting is
often used in spurious cloths, mixed with oil. Cloth prepared in this
way speedily cracks and becomes useless.

Good cloth, with a very stout canvass, is used for covering veran-
dahs, and will last nine or ten years, while spurious cloth will
become useless in the course of one year. Floor cloth is employed to

1836. Scientific Intelligence. 397

cover roofs, as at the manufactory at Knightsbridge, and for gutters.
In the latter case it is remarkable that water remaining in contact
with it produces no injurious effect.

Painted baize for tables is usually manufactured with a smooth
side, and is printed with blocks of a fine structure, resembling calico
blocks. Fine canvass is employed ; several coats of paint are laid
on upon one side, and the other receives one coat, and is then strewed
over with wool, or flocked, as it is called.

II. — Present State of Jerusalem. 13/A. March. — The object
of the lecture delivered by Mr. Davidson was to prove that the
present site of the walls of Jerusalem is the same as that of ancient
times. Dr. Clarke has argued that the Holy Sepulchre must have
been in the present Valley of Hinnom, because we are told that
it was outside the city, and that it was hewn out of a rock. The
lecturer endeavoured to shew, however, that the spot at present
pointed out as the scene of death was actually without the city until
the time of Adrian, who inclosed this portion of the suburbs by a
wall, and that the original may not signify rock but stone. This
common acceptation, however, may be adopted, because the founda-
tions of the houses at present in this quarter of the city are seated on
compact limestone. The lecturer described particularly the present
desolate appearance of the city, (about three miles in circumference)
and the great feeling of disappointment which he experienced on first
obtaining a sight of it, a ?prospect which can scarcely whisper what
it has been. In reference t© the great amount of population of which
we read in Scripture, compared with the extent of surface occupied
by the city, Mr. Davidson observed that the only account we have
of the number of the inhabitants was upon the great occasion of
the feast ; for the storming of the city by the Romans took place
at that period. He described the Mosque of Omar, which occupies
the place of Solomon's Temple This is the great resort of the
Mussulman pilgrims, and, although a fine building, is insignificant
when compared with the great Jewish Temple, which it is calculated
cost above 830 millions of pounds Sterling. A model of the mosque
was exhibited, and the speedy appearance announced of a splendid
panoramic view of the modern Jerusalem, by Mr. Catherwood, taken
from the top of one of the houses within the city.

III. — Manufacture of Pens. By Dr. Faraday. 27th March.
Quills appear to have been employed, at least, as early as the
seventh century. England is supplied with this article from Russia
and Poland, where immense flocks of geese are fed for the sake of
their quills. The quantity exported from St. Petersburg, varies
from six to twenty-seven millions. Twenty millions were last year
imported into England from these countries. We may form some
idea of the number of geese which must be required to afford the
supply, when we consider, that each wing produces about five good
quills and that by proper management, a goose may afford twenty quills
during the year. Hence, it is obvious, that the geese of Great Britain
and Ireland, could afford but a very limited supply. The feathers
of the geese of the latter countries are employed for making beds.

398 Scientific Intelligence. [May

The preparation of quills, or touching; as it is called, is a curious
and nice process. The Dutch possessed the complete monopoly of
the quill manufacture until about JO years ago, when the process
was introduced into this country, and now our quills are infinitely
superior to those of Holland.

The quills are first moistened, not by immersion, but by dipping
their extremities into water and allowing the remaining parts to
absorb moisture by capillary attraction. They are then heated in
the fire or in a charcoal choffer, and are passed quickly under an
instrument with a fine edge which flattens them, in such a manner
as to render them apparently useless. They are then scraped, aud
again exposed to heat, when they are restored to their original form.
This is a remarkable fact, and deserves to be attended to. It may be
illustrated by taking a feather and crushing it with the hand, so as to
destroy it to all appearance. If we now expose it to the action of steam
or a similar temperature, it will speedily assume its pristine condition.

Many of the quills after this preparation are cut into pens by
means of the pen cutters knife, and are also trimmed. A pen cutter
will cut in a day, two-thirds of a long thousand, which consists of
1200 according to the Stationers' computation. A house in Shoe
Lane, cuts generally about six millions of pens, and last year, not-
withstanding the introduction of steel pens, it cut many more than
it had done in any previous years. According to the calculations
of the pen makers not more than one pen in ten is ever mended.

About thirty-one years ago, Mr. Bramah introduced portable
pens into this country from New York, and took out a patent for
their manufacture. The process for making portable pens is to form
a vertical section of the barrel of the quill and polish the pieces.
The pens are then cut with a beautiful instrument, each quill afford-
ing six pens. When they have been nipped coars?ly, a polish is
given with the pen-knife. Sixty thousand of these pens are manu-
factured weekly by two houses. An attempt was made to apply
steel tips to portable quill pens, but the success which was anticipated
did not follow.

Metallic pens appear to have been first introduced as rewards for
merit, but steel pens for writing were first made by Mr. .Wise, in
1803, and were fashioned like goose pens.

A patent was taken out in 1812, for pens with flat cheeks, and in
this way all metallic pens were made for some time, as the rhodium
pen of Dr. Wollaston, and the iridium pen of others. About twelve
years ago, Mr. Perry began to make pens, and about six years ago
they began to be manufactured at Birmingham. The steel is pressed
into thin sheets by a rolling press. It is then cut into slips, annealed
for fourteen hours, and again passed under the roller. By means
of a peculiar cutting machine the pens are formed in a falchion shape.
But one half of the steel is thus wasted, and no use has been found
for it. It is so thin that it cannot be welded, and it cannot be melted
because it catches fire, and burns in consequence of the air getting
access between its thin leaves. The fibres of the steel run in one
direction, and the pens are cut in accordance with this disposition.
The pens are then annealed. The preparation for forming the slit
then takes place. An extremely fine edged chisel is brought down
upon each separately, and is allowed to penetrate I through its sub-

1835.] Scientific Intelligence. 399

stance. The edge of this instrument is finer than any razor, but is
much harder, as it does not require to receive an edge during the whole
of the day. This superior quality is given to the steel by beating it
for several hours with a hammer. It is an important fact, and appears
to have been discovered by the pen manufacturers. A triangular
piece is next cut out at the upper end of the slit in the pen, which is
called piercing. The next object is to give them their proper shape,
which is effected by means of a punch fitting into a corresponding
concavity.

The pens are then heated red hot and dipped into oil, which must
be at least 3 feet deep. The oil in a few weeks looses its properties
and becomes charred. The next operation is polishing. This is
effected in a peculiar apparatus, called emphatically the devil, con-
consisting of a fly wheel and box in which the pens are placed, and to
which a motion is given, resembling that required in shaking together
materials in a bag. This motion is continued for eight hours, when
the pens are found to be completely deprived by the friction against
each other of any asperities which might have existed on their edges,
and though not visible to the naked eye, would have obstructed the
free motion of the pen in writing. After this they are tempered in
a box, shaken and brought to a blue colour, being carefully watched,
and the heat lessened whenever a shade of yellow is observed on their
surface. The split is now completed by touching its side with a pair
of pincers.

With regard to the number of steel pens made, from information
communicated to Dr. Faraday, it appears that Mr. Perry manufac-
tures one hundred thousand weekly, or five million two hundred
thousand per annum. Mr. Gillot employs 300 pair of hands, and
consumes 40 tons of steel annually. Now, 1 ton of steel produces
about two millions of pens. Hence, this manufacturer alone makes
eighty millions of pens annually. The total quantity of steel em-
ployed in this country for making pens amounts to 120 tons, which is
equivalent to about two hundred millions of pens.

Notwithstanding the immense product of the manufacture, it is
remarkable that the consumption of quills has not diminished, indeed,
it is on the increase ; this may be accounted for by the consideration
that within the last 10 or 15 years, the population has increased ^,
and 3 people now can write for 1 at the commencement of that pe-
riod ; and besides, both the Continent and America are supplied by
us. When first introduced, steel pens were as high as 8s. per gross,
then they fell to 4s. and recently have been manufactured at Birming-
ham at as low a price as 4d. the gross. It appears that the only in-
terest that has suffered by the employment of steel pens, is that of the
pen-knife makers. Pens have also been made of horn and tortoise-
shell, and it is no small consolation to consider that if steel should fail
us we can have recourse to such abundant materials.

Scientific Books in the Press and on hand.

MARTINET'S MANUAL OF PATHOLOGY: Edited by Jones Quain.M.D.
Professor of Anatomy and Physiology in the University of London. A New-
Edition, with numerous Additions.

NATURAL HISTORY of the ORDER CETACEA and the OCEANIC
Inhabitants of the Arctic Regions. By H. W. Dewhubst, Surgeon.

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RECORDS

OF

GENERAL SCIENCE

JUNE, 1835.

Article I.

Biographical Notice ofM. Chaptal. (Ann. de Chim. lii. 205.)

Jean Antoine Chaptal was born at Nozaret (Lozere) in
1756. He was educated at Mende, from whence he repaired
to the School of Medicine at Montpellier, and then to Paris.
In 1781 he was appointed to the Chair of Chemistry founded
by the States of Languedoc. Having been left a large fortune
by his uncle, he originated a number of chemical manufac-
tories in his adopted city, and thus raised in his own country
products which previously were entirely derived from foreign
lands. In 1793 he was called to Paris by the Committee of
Safety, to manage the saltpetre manufactory. The great
establishment of Grenelle became thus the scene of that
zeal and industry which were so eminently illustrated during
the whole of Chaptal's career. The Polytechnic School
numbered him among its first professors. The Institute
elected him in the place vacated by the death of M. Payen,
and Napoleon, after the establishment of the Consulate,
called him to the Council of State. In the year 9 he
was made minister of the interior, and towards the end
of the year 12 quitted his high functions. His ministry
was distinguished by many signal benefits. He devoted
much time to the examination of humane establishments,
which, from the unfortunate state of the times, had been
sadly neglected. He liquidated their debts, furnished them
with new funds, regulated their administration, and insti-
tuted gratuitous commissions for governing them. At Paris
a general council was instituted over these, which produced
vol. i. 2d

402 Biographical Notice of [June

most important ameliorations in all the charitable establish-
ments of the capital. The sisters of charity, so worthy of
their name, who sympathize with the unfortunate, were
recalled into the hospitals. Chaptal inspected the foundling
hospitals, and endeavoured to prevent abuses in the admis-
sion of their inmates. He created houses of refuge in order
to repress mendicity. He neglected no precaution for
checking the small pox, by propagating vaccination, of which
Larochefoucauld Liancourt destroyed the benefit. He ori-
ginated the Vaccination Society, which exercised its salutary
influence until it was suppressed by a bungling administra-
tion. He introduced hard labour in prisons, and adopted
measures for improving the regulation of these domiciles.
The interests of the public health likewise attracted his
care. He revised and amended the laws relating to medi-
cine and pharmacy ; he organized lying-in hospitals, and
regulated the exploring of mineral waters.

But, not the least of his attention was directed towards
the advancement of the industry of his country ; he esta-
blished chambers of commerce, and consulting councils of arts
and manufactures. The school of arts and the conservatory
having become a great museum and an important seminary,
are distinguishing marks of the care and anxiety which
inspired him for increasing the opportunities and means of
instruction. He published useful processes, visited the
tradesmen, conversed with them, offered them his advice,
praised their discoveries, and favoured processes and appa-
ratus coming from abroad. His character has been drawn in
high terms by Thenard : " Endowed with a kind heart,
of a mild and gentle character, moderate in his tastes and
opinions; full of benevolence to his fellow creatures, of
affectionate regard for his associates, of devotion for his
friends; ready to do a favour when in his power, and
doubling it by the grace with which he conferred it ; un-
happy when obliged to refuse, and always softening the
refusal by expressions which shewed the goodness of his
heart. Possessing a handsome fortune, which he had nobly
acquired, and loaded with honours, Chaptal appeared to
have it in his power to foil the strokes of fortune. Yet
some reverses and disappointments which he could not
foresee, and certainly did not merit, tended to sadden the
end of }iis brilliant career. But he knew how to support

1835.] M. Chaptal. 403

them with dignity. Not a murmur or sigh escaped from
his lips, a proof, to the end, of the greatness of his mind.
He consoled himself by study, and by fulfilling duties which
had been imposed on him, or which he had created for
himself. Then feeling his end approaching, he resigned
himself like a philosopher prepared for leaving a world
where he had but a few days to remain, and died beloved,
surrounded by his numerous family, bestowing on them his
blessing as his last farewell." He died at Paris 29th July
1832, in the 76th year of his age. At his death he was
grand officer of the Legion of Honour. He was one of the
first founders of the Society of Encouragement, over which
he presided for many years. His principal works were

1. Elemens de Chimie, 3vols.8vo. The first edition ap-
peared in 1790, the fourth in 1803. It was translated into
most languages.

2. Essai sur le Perfectionnement des Arts Chemiques en
France, 8vo. 1800.

3. Art de faire, de Gouverner et de Perfectioner les Vins,
8vo. first edition 1801, second 1811.

4. Art du Teinturier et du Degraisseur, 8vo. 1800.

5. Essai sur le Blanchiment, 8vo. 1801.

6. Chimie Appliquee aux Arts, 4 vols., 8vo. 1807.

7. Art du la Teinture du Coton en Rouge, 8vo. 1807.

8. De l'industrie Francaise, 2 vols., 8vo. 1819.

9. Memoire sur le Sucre de Betteravas, 8vo. first edition
1815, third 1821.

10. Chimie Appliquee a l'agriculture, 2 vols., 8vo. first
edition 1823, second 1829.

11. Traite sur la Culture de la Vigne, 8vo. 1801.

Article II.

Chemical Analysis of Gadolinite, together with an Examination
of some of the Salts of Yttria and Cerium. By Thomas
Thomson, M.D., F.R.S., L. and E., &c, Regius Professor
of Chemistry in the University of Glasgow ; and Andrew
Steel, M.D.

I. ANALYSIS OF GADOLINITE.

The specimen of gadolinite which furnished materials for
the experiments contained in this paper, was purchased

2d2

404 Dr. Tliomas Thomson and Dr . SteeVs [June

several years ago from a German mineral dealer. He
stated that he had accidentally observed it in a collection of
minerals in Sweden, from the proprietor of which he pro-
cured it, and that its original locality was not certainly
known. It weighed several ounces.

It was an amorphous mass, having a very deep green
colour, so as to appear to the eye almost black.

The lustre on the fresh fracture was vitreous and splen-
denti But when broken in certain directions it presented
a surface almost dull, and having a whitish aspect; but
when viewed through a microscope no extraneous matter
could be observed. The colour and want of lustre was
probably owing to long exposure to the air, which had
acted through certain natural rents in the mineral. For it
broke with much more facility, so as to exhibit the dull
than the splendent surface.

Hardness 6*5; specific gravity at 60° from 4*1493 to
4-1795. The mean was 4-1607.

Its other characters being the same as those of common
gadolinite need not be described here. Twenty grains, by
ignition, acquired a brownish colour, and lost 0*198 grains
of weight, or almost one per cent. This loss was doubtless
owing to the escape of water.

During the pounding of the mineral for analysis small
metallic looking grains were observed, which were carefully
picked out and submitted to the following examinations.
They were malleable, infusible before the blowpipe, not
acted on by muriatic acid, but dissolving slowly in aqua
regia. The solution had a deep orange colour, a .few
blackish grains remaining at the bottom. It afforded a
yellow precipitate with sal ammoniac and salts of potash
and was obviously platinum. From 120 grs. of the mineral
2*33 grs. of platinum were picked out. But the quantity
was found to vary in different pieces.

We attempted to analyze gadolinite by the processes em-
ployed by Berzelius. But we found that the peroxide of
iron, which we had precipitated by benzoate of ammonia,
contained also glucina, from which we could not separate
it by means of benzoate of ammonia however carefully
added. This led us to a careful investigation of the pro-
perties of cerium, yttria, and glucina. The facts ascer-

1835. Chemical Analysis of Gadolinite, Sfc. 405

tained suggested the following method of analyzing
gadolinite : —

A. 25 grs. of the mineral, finely pounded, were boiled in
a flask with aqua regia, till the whole was decomposed.
The gelatinous silica remaining, collected on a filter, and
well washed, weighed, after ignition, 6*22 grs.

B. The residual liquid was evaporated to dryness, and
the solid matter remaining, digested for some time in
distilled water. A solution of oxalic acid was then added,
as long as it occasioned a precipitate, and until this precipi-
tate was of a perfectly white colour. The oxalic acid re-
tained in solution the iron, glucina, &c, and threw down
the yttria and cerium in the state of oxalates. The whole
was thrown upon a filter, and the white insoluble matter
was well washed. When dry it was a beautiful light,
snow-white powder, and weighed, after ignition, 12*617
grs. It had now assumed a light yellow colour, and was a
mixture of oxide of cerium and yttria.

Various methods of separating these two substances from
each other were tried, but without success, on account of
the perfect correspondence of the two in all their properties,
We were, therefore, obliged to have recourse to the common
method of putting a quantity of solid sulphate of potash
into a neutral solution of the yttria and oxide of cerium,
which threw down the cerium and left the yttria. But as
the quantities were never absolutely the same in two suc-
cessive experiments, this method is certainly suspicious.
By this method the 12*176 grs. were resolved into

Yttria 11*087

Peroxide of cerium . * 1-530= 143 protoxide.

12*617

C. The oxalic solution from (B.) was evaporated to dry-
ness, and ignited to destroy the oxalic acid. The residue
was dissolved in muriatic acid, by the assistance of heat,
with the exception of a few blackish grains. These were
at first supposed to be charcoal from the oxalic acid, but
after being collected and ignited they proved to be plati-
num, weighing 0*45 grs.

D. The muriatic acid solution was now evaporated to
dryness, and to insure perfect neutralization, heated, so
that a small portion of the iron became insoluble on its

406 Dr. Thomas Thomson and Dr. Steels [June

being again digested in water. Into this muddy liquid a
quantity of benzoic acid was thrown, and well stirred.
After standing 24 hours the whole iron was found to be
precipitated, while the glucina remained in solution .* The
benzoate of iron was collected on a filter, washed, dried,
and ignited. The peroxide of iron obtained weighed 3*75
grs. = 3*375 protoxide. On trial it appeared perfectly
pure.

E. The residual solution was now mixed with ammonia,
which threw down a white floculent precipitate. It was
collected on a filter, well washed and dried. After ignition
it had a dirty brownish white colour, and weighed 3*182 grs.

It dissolved in acids, forming very sweet tasted salts.
The sulphuric acid solution crystallized, though imperfectly.
The solution gave the following characters with re-agents :

Prussiate of potash : No precipitate.

Caustic ammonia : A white precipitate, not soluble in
an excess of the ammonia.

Carbonate of ammonia : White precipitate, soluble in
an excess of the alkali.

Caustic of potash : A white precipitate, soluble in an
excess.

Oxalic acid : No precipitate.

Oxalate of ammonia : No precipitate.

Benzoate of ammonia: No precipitate.

Tincture of nutgalls : A white precipitate.

Gallic acid : No precipitate.

The white matter obtained was therefore glucina.

The preceding analysis gave the constituents of gadolinite
as follows : —

Silica 6*220 - 24*880

Yttria 11*087 - 44*348

Protoxide of cerium . . 1*430 - 5*720

Glucina 3*182 - 12*728

Protoxide of iron . . . 3*375 - 13*500

Platinum 0*450 - 1*800

Moisture ..... 0*247 - 1*088

25*991 - 104*064

* It had been ascertained by experiment that benzoate of ammonia throws down
glucina, which benzoic acid does not ; and that, with care, the peroxide of iron
may be completely thrown down by benzoic acid.

1835.] Chemical Analysis of Gadolinite, fyc. 407

Suspecting that the increase of weight in this analysis,
which rather exceeds 4 per cent., might have been owing
to the yttria not having been sufficiently ignited, * it was
repeated in the following manner : —

A. 30 grs. of the finely powdered mineral were boiled
in a flask with nitro-muriatic acid till the whole was decom-
posed. The silica separated in the usual way, and most
carefully washed with boiling distilled water, weighed,
after ignition, 7*3 grs. It was beautifully white and
pure.

B. The residual solution was mixed with sal-ammoniac,
and evaporated to dryness. When again dissolved only a
mere trace of platinum remained.

C. The solution was now mixed with oxalic acid, and, to
ensure the precipitation of any manganese that might exist
in the mineral, the whole was evaporated to dryness. The
white matter remaining undissolved on digesting the mass
in water, after being well washed and ignited, weighed 15
grs. It was of a light-yellow colour.

D. It was dissolved in nitric acid. The solution was
evaporated to dryness, the residue dissolved in a small
quantity of water, and crystals of sulphate of potash were
allowed to remain in the solution for a week. The clear
liquid was then drawn off, and the white matter, after being
well washed in a saturated solution of sulphate of potash,
was dissolved in dilute nitric acid, and precipitated by am-
monia, and boiled in a flask, to ensure the complete sepa-
ration of the sulphuric acid. The peroxide of cerium, after
ignition, weighed 1*400 grs. = 1*3 grs. protoxide.

E. The sulphate of potash solution from (D) was mixed
with a solution of carbonate of ammonia in great excess.
To what remained after the clear liquid had been drawn off"
fresh solutions were added, and this was repeated six times
before the whole was dissolved. There remained only a
few flocks, not weighing 0*01 gr. As they became black
when dried they probably consisted of oxide of manganese,
but the quantity was too small to permit the use of re-agents
to determine its nature.

* We had found that the carbonate of cerium is not decomposed by exposure
to a pretty strong red heat.

408 Dr. Thomas Thomson and Dr. SteeVs [June

The 15 grs. of white matter were therefore composed of

Yttria 13*6

Peroxide of cerium . 1*4
Manganese . . . trace

15-0
F. The oxalic solution from (C.) was precipitated by ammo-
nia, and the precipitate washed to get rid of the oxalic acid.
It was then dissolved in muriatic acid. To separate the glu-
cina from the iron, caustic potash, and then carbonate of am-
monia were tried ; but neither of these methods was found to
answer. The separation was therefore accomplished by the
same process as in the former analysis. There were obtained
Peroxide of iron . . . 4*53 = 4*077 protoxide

Glucina 3-47

This analysis gives the composition of gadolinite as
follows : —

Silica 7-300 - 24-33

Yttria 13-600 - 45-33

Protoxide of cerium . . 1*300 - 4-33

Glucina 3-470 - 11*60

Protoxide of iron . i i 4-077 - 13-59

Platinum trace - trace

Manganese trace - trace

Moisture 0*296 - 0*98

30*043 100*17

This analysis gives us the constituents of gadolinite as
follows : —

12*16 atoms silica

8*06 ,, yttria

0*88 ,, protoxide of cerium

3*91 ,, glucina

3* ,, protoxide of iron.

Were we to suppose the protoxide of iron to be an acci-
dental ingredient, we might consider gadolinite as com-
posed of 2 atoms silicate of yttria,

1 atom silicate of glucina and cerium,
or we might consider it as composed of

1 atom silicate of cerium,

4 atoms silicate of glucina,

8 ,, silicate of yttria.

1835.] Chemical Analysis of Gadolinite, Sfc. 409

If the protoxide of iron be an essential constituent, the
oxide of cerium, glucina, and protoxide of iron must be in
the state of disilicates.

II. EXPERIMENTS ON YTTRIA.

The neutral colourless sulphate of yttria was dissolved in
water, and the solution, when treated by re-agents, exhi-
bited the following properties : —

1. Prussiate of potash : A white chalky precipitate.

2. Ammonia : A white precipitate, not soluble in excess.

3. Potash : A white precipitate, not soluble in excess.

4. Alkaline carbonates : A white precipitate, soluble in
excess.

5. Infusion of nutgalls : O.

6. Gallic acid : O.

7. Tincture of nutgalls : White, merely from the alcohol.

8. Alcohol: White.

9. Chromate of potash : Yellow.

10. Bichromate of potash : O.

11. Hydriodate of zinc : tO.

12. Sulphate of potash : O.

13. Oxalic acid : A white precipitate.

14. Oxalate of ammonia : A white precipitate.

When a solution of muriate of yttria was exposed to the
galvanic action, chlorine was given out at the negative pole,
and a small quantity of some other gas, (probably hydrogen)
at the positive pole. A quantity of gelatinous matter col-
lected round the negative wire.

Yttria is not altered by having a current of sulphuretted
hydrogen passed over it while heated to redness in a green
glass tube.

When phosphorus in vapour is passed over yttria heated
to redness, a vivid ignition takes place, but no combination
is formed. The weight of the yttria remains unaltered.

III. SALTS OF YTTRIA.

1. Sulphate. — Sulphuric acid acts with considerable vio-
lence on anhydrous yttria, and with the evolution of consi-
derable heat. The solution crystallizes in doubly oblique
prisms, and also in acute rhomboids.

410 Dr. Thomas Thomson and Dr. Steel's [June

The taste is sweet and astringent, and the crystals are
insoluble in alcohol.

100 parts of water, at the temperature of 65° dissolve
very nearly 7*19 grs. of the crystallized salt.* The sp. gr.
of the salt is 2*565. It reddens vegetable blues. It may
be exposed to a gentle heat without decomposition, but is
partly decomposed at a higher temperature.

12*8 grs. of the crystals lost, when dried at the highest
temperature of the sand-bath, 3*00 grs. The crystals had
not lost their shape, but had become opaque, and of a pearl
white colour. They were dissolved in water, and mixed
with a solution of muriate of barytes. The sulphate of
barytes weighed, after being well washed and ignited, 13*6
grs. = 4*869 grs. of acid. This gives the composition of

the salt, Yttria 5*111 or 5*45

Sulphuric acid . . 4*689 ,, 5*
Water 3*000 „ 3*19

12*800

This analysis was repeated with the following result : —
18*62 grs. of the crystals lost, by exposure to a gentle
heat, 33*2 grs. The beautiful pearl white residuum dis-
solved completely in water. The acid was precipitated by
nitrate of lead, giving 27*30 grs. of ignited sulphate of
lead = 7*18 grs. of sulphuric acid. The residual liquid
was freed from excess of lead by sulphuric acid, and the
yttria precipitated by ammonia. It weighed, after ignition,
8*0 grains. This analysis gives,

Yttria . . . 8*00 or 5*59
Acid . . . 7*18 „ 5*
Water. . . 3*32 „ 2*31

18*50
A third repetition of the analysis was made as follows : —
30 grs. of the crystals, purified by washing in alcohol, to
free them as much possible from hygrometic moisture, were
heated on the sand-bath for 12 hours, and then gently
ignited. The loss of weight was 6*7 grs. The residual salt
dissolved completely in water. The yttria was precipitated

* An excess of the salt was shaken on the sand-bath occasionally for three days ,
306 grs. of this solution left, when evaporated, 22 grs. of the crystallized salt.

1835.] Chemical Analysis of Gadolinitey tifc. 411

by oxalate of ammonia. The oxalate collected on a filter,
well washed and ignited, left 12*257 grs. of yttria. The
residual liquid, after being mixed with a little nitric acid,
was precipitated by chloride of barium. The sulphate
of barytes obtained, weighed, after ignition, 32 grs. = 11*03
grs. of sulphuric acid. This analysis gives,

Yttria .... 12*257 or 5*54
Sulphuric acid . . 11*030 ,, 5*
Water .... 6*700 „ 3*04

29*987
These three analyses, corresponding so closely in the
proportion of acid to base, leave little doubt that the atomic
weight of the base in this salt is as high as 5*5. If the
yttria employed by. Berzelius contained glucina, it will
account for his finding it less. Probably the true compo-
sition is, Yttria 5*5

Sulphuric acid . . 5*
Water 2*25

12*75

To verify this, solutions of 12*75 sulphate of yttria, 8*875
oxalate of ammonia were mixed. The residual liquid was
neither altered by sulphate of yttria nor oxalate of ammonia.
But when the residual liquid was evaporated nearly to dry-
ness, it was found to give traces of yttria by prussiate of
potash. It was mixed with caustic ammonia, which threw
down a small quantity of yttria, weighing 0*32 grs. The
oxalate collected on a filter and washed, left, when ignited,
5*1 grs. of yttria. 8*875 grs. of oxalate of ammonia, there-
fore, do not decompose completely 12*75 grs. of sulphate of
yttria. Probably because the oxalate was not quite dry.
Solutions of 12*75 grains sulphate of yttria,
,, 20*75 ,, nitrate of lead,

were mixed. The supernatant liquid was neither affected
by sulphate of soda nor nitrate of lead. For greater cer-
tainty, it was divided into two portions : into the one was
poured nitrate of lead, and into the other sulphate of soda.
After standing 24 hours, a mere trace of opacity was per-
ceptible at the bottom of the vessel, to which the nitrate
of lead had been added.

412 Dr. Thomas Thomson and Dr . Steels [June

No bisulphate of yttria could be formed. When we eva-
porate a solution, containing even a considerable excess of
acid, common sulphate of yttria is obtained.

2. Acetate of yttria. — This salt crystallizes in beautiful
rhombs. It has a sweet taste and is not altered by expo-
sure to the air.

10*58 grains of the crystals heated on the sand-bath, fell
to a white powder and lost 2*14 grains. After ignition,
the yttria remaining weighed 3*92 grains. Hence, its con-
stituents are,

Yttria . . . 3*92 or 5*5
Acetic acid. . 4-52 „ 6*341
Water ... 2-14 „ 3000

10-58

In a second analysis, 9*2 grains lost on the sand-bath
2-05 grs., and after ignition there remained 3*35 grs. of
yttria. Hence, it was composed of,

Yttria .... 338 or 5*5
Acetic acid . . 3*80 „ 6*238
Water .... 2*05 „ 3*365

9*2
These analyses shew that the salt is composed of
1 atom yttria .... 5*5
1 atom acetic acid . . . 6*25
3 atoms water .... 3*375

3. Oxalate of yttria. — Oxalic acid seems to combine in
various proportions with yttria. The oxalates, however,
have all the same beautiful snow-white colour. They
appear to be quite insoluble in water ; but after being once
or twice washed on a filter, the liquid begins to pass
through muddy.

1st. 11*38 grs. of anhydrous sulphate of yttria gave by
oxalate of ammonia, 12*9 grs. of oxalate of yttria, which,
when ignited, left 5*97 grs. of yttria.

2nd. 10 grs. of yttria dissolved in muriatic acid gave 22*4
grs. of oxalate of yttria.

3d. 30*04 grs. of oxalate of yttria, dried as well as pos-
sible, left, after ignition, 12*422 grs. of yttria.

1835.] Chemical Analysis of Gadolinite, Sfc. 413

These experiments seem to prove that the neutral oxalate
is a compound of,

1 atom yttria . . . 5*5

1 atom oxalic acid . 4*5

2 atoms water . . . 2*25

12-25

Sesqui-oxalate of yttria. — When, instead of precipitating
the sulphate of yttria by the oxalate of ammonia, we reverse
the process, the precipitate is a sesqui-oxalate, as the follow-
ing experiments shew : —

1st. 8*875 grs. of oxalate of ammonia were dissolved in
water, and a solution o(f sulphate of yttria was added as
long as it occasioned a precipitate. The precipitate being
collected on a filter, and well washed and dried, weighed
9*43 grs. and after ignition 4*008 grs. of yttria remained.

2nd. The same experiment being repeated, gave 9*9 grs.
of oxalate, leaving, after ignition, 4*092 grs. of yttria.

Now, since 8*875 grs. of oxalate of ammonia contain 4*5
grs. of oxalic acid, we have from

1st. experiment: 2nd experiment :

Yttria . 4*008 or 5*5 - 4*092 or 5*5
Acid .4*5 „ 6* - 4*5 „ 6*

This is nearly \\ atom acid to 1 atom base.

Dinoxalate of yttria. — When yttria is precipitated from
a solution containing an excess of acid, by oxalic acid, we
sometimes obtain the neutral oxalate, but occasionally
another compound, which, however, has exactly the same
appearance.

12*55 grs. of this, on ignition, left 9*45 grs. of yttria.
Hence, it seems to have been composed of,
2 atoms yttria . . 1*1
1 atom acid . . . 4*5

Water 0*28

Doubtless hygrometrical.

4. Nitrate of yttria. — When nitric acid is poured upon
yttria, no immediate action takes place ; but, if the mixture
be gently heated the yttria dissolves at once, with the
evolution of nitrous gas. When evaporated the salt cry-
stallizes in prisms. When gently heated it melts into a
beautiful transparent glass, and is completely decomposed
by a very slight heat. It is very deliquescent.

414 Dr. Thomas Thomson and Dr. SteeVs [Junk

An analysis of the crystals offered very unsatisfactory
results, from the impossibility of drying them. 10 grs.
lost, when ignited, 6*56 grs. 5*5 grs. of yttria were dis-
solved in pure nitric acid, and heated until the whole fused
into a transparent glass. The weight had increased to 12*4
grs. It was again heated till the glass began to get opaque,
it now weighed 11-72 grs. But a considerable portion of
it was insoluble in water, evidently shewing that some of
the acid had been driven offv If the salt was neutral, (as
must have been the case,) the first experiment leads to the
conclusion that its constituents are,

Yttria . . . 5*5 or 1 atom.

Nitric acid . 6*5 ,, 1 atom.

Water . . . 225,, 2 atoms.

14-25

5. Muriate of yttria. — Muriatic acid dissolves yttria very
readily. The solution, when carefully evaporated, crystal-
lizes in large right prisms, with two opposite angles, trun-
cated so as to constitute six-sided prisms. The taste is
sweet and astringent. The crystals are very deliquescent.
When heated the salt undergoes the watery fusion, and is
decomposed at a red heat.

Its analysis did not afford very satisfactory results, as,
from its easy decomposition and rapid deliquescence, it is
exceedingly difficult to free the crystals from the mother
liquor.

10 grs. of the crystals lost, when dried on the sand-bath,
2*37 grs. The residue did not dissolve completely in water,
indicating that some of the acid had been driven off. The
yttria, precipitated by ammonia, weighed 4-08 grs., and the
residual solution, after being neutralized by nitric acid,
gave 11*59 grs. of fused chloride of silver = 2*93 grs. of
muriatic acid. This gives the constitution of the salt,
Yttria . . . 4*08 or 5*5
Muriatic acid . 2-93 „ 3*94
Water . . . 2-37 „ 3-1

In another analysis, 15*65 grs. of the crystals dissolved
in water, gave 19*881 grs. of chloride of silver, = 5*04
grs. acid; and by ammonia, 5*21 grs. of yttria. This
gives us : —

1835.] Chemical Analysis of Gadolinite, Sfc. 415

Yttria . . . 5*21 or 5*5
Muriatic acid . 5*04 „ 5-37
Water . . . 5-40 „ 5*5
The mean of these two analyses gives us the following
constituents : —

Yttria .... 5-5
Muriatic acid . 4*65
Water. . . . 4*3

This, though not quite accurate, comes near enough to
shew that the salt contains an atom of acid, united to an
atom of base. If it be a chloride, as is probable, then its
constituents are,

1 atom yttrium . . . 4*5
1 atom chlorine ... 4 5
5 atoms water . . . 5*625

6. Carbonate of yttria. — Yttria has considerable affinity
for carbonic acid, even when precipitated by caustic am-
monia. For, when dried in the open air it is partially
converted into a carbonate. Carbonate of yttria is a white
tasteless powder, insoluble in water, but soluble in the
alkaline carbonates. When a solution of yttria, in an
alkaline carbonate, is heated, the yttria is precipitated in
the state of a carbonate, but is again dissolved when the
solution cools.

6*2 grs. of this carbonate lost, by a red heat, 2*53 grs.
Hence, its constituents were,

Yttria . . . 3*67 or 5*5
Carbonic acid . 1*83 „ 2-75
Water . . . 0-70 „ 1*05

6-20

Through a quantity of freshly precipitated carbonate of
yttria, suspended in water, a current of carbonic acid gas
was passed for a considerable time, without any alteration.
Hence, we have no evidence of the existence of a bicarbo-
nate of yttria.

7. Tartrate of yttria. — A beautiful light white powder,
obtained by precipitating sulphate of yttria by tartrate of
potash. 5*2 grs. of it lost, by ignition, 3*26 grs. This
would indicate for its composition :

416 Dr. Thomas Thomson and Dr. SteeVs [June

Yttria . . . 1'94 or 5*5
Tartaric acid . 2-96 „ 8-25
Water. . . 0*36 „ 1*02
8. Phosphate of yttria.— Phosphoric acid does not dis-
solve yttria, but the phosphate may be obtained by precipi-
tating sulphate of yttria by phosphate of soda. The salt
falls in gelatinous flakes, having, when on the filter, much
the appearance of hydrate of alumina. After ignition it
still retains its opalescent appearance, but becomes more
compact, and of a vitreous lustre, though the particles are
not agglutinated.

9-8 grs. of anhydrous sulphate of yttria gave 9*72 grs. of
hydrous phosphate, reduced by a red heat to 7*92 grs.
Now, as 9*8 grs of sulphate contain 5*133 grs. of yttria, we
have the constituents,

Yttria 5*133 or 8*25 - \\ atoms.

Phosphoric acid. . 2*786 „ 4*477 - 1 „
Water 1*800 „ 2*8 - 2\ „

9*719
It is, therefore, a disesquiphosphate, apparently similar
to the native disesquiphosphate.

IV. OF CERIUM.

Cerium, as is well known, forms two oxides. We did
not succeed in our attempts to obtain the protoxide in a
separate state, but the salts containing it are readily formed.
The peroxide has a yellow or brown colour, according to
the mode in which it is obtained. Both oxides form salts
with acids. The salts containing the protoxide have an
amythystine colour, and are quite permanent. Those con-
taining the peroxide are yellow, or orange, and easily
decomposed. The sp. gr. of the peroxide of cerium is 5*33.

The protoxide of cerium, when in the state of sulphate,
may be distinguished by the following characters :

Prussiate of potash : A white chalky precipitate.

Ammonia : A white gelatinous precipitate, not soluble
in an excess of ammonia.

Potash : A white precipitate, insoluble in an excess.

Alkaline carbonates : A white precipitate, soluble in an
excess, but precipitated again when boiled.

1835.] Chemical Analysis of Gadolinite, $fc. 417

Infusion of nutgalls : O.

Gallic acid : . . . O.

Tincture of nutgalls : White, merely from the alcohol.

Chromate of potash : A yellow precipitate.

Bichromate of potash : O.

Hydriodate of zinc : O.

Sulphate of potash : No immediate action.

After some time a copious white powder falls.
Oxalate of ammonia : A white powder.
Oxalic acid : A white curdy precipitate

Phosphate of soda : A white precipitate.
Tartrate of potash : A white precipitate.

V. SALTS OF CERIUM.

1. Sulphated protoxide. — This salt may be obtained by
dissolving peroxide of cerium in sulphuric acid, and adding
a little muriatic acid. Chlorine is given oft*, and a colour-
less solution obtained, which when sufficiently concentrated
yields prismatic crystals of an amythystine colour. When
alcohol is added to the concentrated solution, the salt falls
in fine silvery needles : its taste is agreeably sweet and
astringent. Its specific gravity is about 2*5 : 100 parts of
water at the temperature of 60°, dissolve 6*47 of the
crystallized salt. When heated, it becomes white and
opaque, but cannot be rendered anhydrous without losing
a little of its acid. After having been once or twice cry-
stallized it is quite neutral.

The analysis of this salt was attended with unexpected
difficulty. It was not till after a considerable waste of time
and matter, that the varying results were found to arise
from the formation of various double salts. When the acid
was thrown down by barytes, the sulphate obtained after
the most careful washing, contained abundant traces of
cerium. When ammonia was employed to throw down
the oxide, a subsalt fell, and the acid being driven off
from this salt by a red heat, gave an apparent loss, and
rendered the results quite unintelligible.

I. 12*75 grains of the crystallized salt lost by a gentle
ignition 1*6 grain ; the residuum dissolved completely in
water; the cerium was thrown down by oxalate of ammonia.
The oxalate was collected on a filter, well washed with
boiling distilled water, dried and ignited : 6*58 grains of
peroxide of cerium were obtained . From the residual solu-

vol. i. 2 E

418 Dr. Thomas Thomson and Dr. SteeVs [June

tion mixed with nitric acid, the sulphuric acid was thrown
down by means of chloride of barium. The well washed
sulphate weighed after ignition 13*36 grs. =4*6 grs. sul-
phuric acid. This analysis gives us,

Peroxide of cerium . . . 6*58 or 7*15

Sulphuric acid 4*60 ,, 5*

Water ....... 1*90

13-08
Increase of weight by peroxidizing the cerium 0*33 gr.

II. 20 grs. of the salt in small silvery needles when ex-
posed to a low red heat lost 4*67 grs. The remainder dis-
solved completely in water. The solution was mixed with
nitric acid, and after a sufficient quantity of muriate of
barytes had been added, the whole was boiled in a flask,
the sulphate collected, well washed and dried weighed
20*05 grs., reduced by ignition to 18*967 grs. =6*54 grs. of
sulphuric acid.

Other 20 grs. of the salt treated in the same way, but
substituting muriatic for nitric acid gave 18*86 grs. of
sulphate of barytes =6* 51 grs. sulphuric acid; the mean of
these two trials gives us 6*52 grs. of sulphuric acid from
20 grs. of the salt.

20 grs. of the same needles gave by oxalate of ammonia
19 grs. of hydrous oxalate, leaving after ignition in a close
crucible a yellow powder, weighing 9*27 grs. When the
ignition was repeated in an open crucible, the weight was
not altered, but the colour became red. This analysis
gives us

Peroxide of cerium . . . 9*27 or 7*10

Sulphuric acid 6*52 ,, 5*

Water 4*67 „ 3*5

20-46
Here the increase of weight from the peroxidizement of
the cerium is 0*46 gr.

III. 19 grs. of the same crystals lost by gentle ignition
4*20 grs. The residuum was introduced into a flask and
boiled with a solution of carbonate of ammonia, and filtered
while boiling hot. The carbonate of cerium after careful
washing weighed when dry 10*7 grs. Being exposed to a
strong red heat, it left 8*89 grs. of peroxide of cerium.

1835.] Chemical Analysis of Gadolinite, Sfc. 419

The residual solution was mixed with nitric acid in excess
and precipitated by chloride of barium. The sulphate of
barytes collected on a filter, well washed, dried and ignited
weighed 18*53 grs. =6*42 grs. of sulphuric acid. This
analysis gives,

Peroxide of cerium ... 8-893 or 6-92
Sulphuric acid .... 6-420 „ 5*
Water 4-2 „ 3-25

19-513
Increase of weight by the peroxidizement of the cerium,
0-513 grs.

These analyses give as the atomic weight of the peroxide
of cerium, 1st. . . 7-15

2nd. . . 7-10
3d. . . 6-92
Mean . 705
This mean comes so near 7 as to leave little doubt that
it is the true number. The increase of weight of the oxide
in each analysis comes very near half an atom of oxygen.
The reason why it is not exactly so, is that we were unable
to render the salt perfectly anhydrous, without decomposi-
tion. It is pretty evident then that the atomic weight of
protoxide of cerium is 6*5, and that the true composition of
cerium is doubtless,

1 atom protoxide . . . 6*5
1 atom sulphuric acid . 5*
3 atoms water .... 3*375

14-875

2. Sulphated Peroxide of Cerium. — This salt may be
obtained by dissolving peroxide of cerium in dilute sulphuric
acid by a gentle heat. The solution takes place slowly.
The orange coloured solution thus formed, when cautiously
evaporated, yields beautiful silky needles of a lemon-yellow
colour. When alcohol is added to the concentrated solu-
tion the salt falls down exactly like a piece of soft yellow
resin, very adhesive, not exactly deliquescent, but becoming
softer when exposed to the air.

The crystals are quite permanent in the air. When dis-
solved in a small quantity of water they are decomposed

2e2

420 Dr. Thomas Thomson and Dr. Steel's [June

into a solution of sulphated protoxide, and a yellow insoluble
subsalt, which precipitates. The sulphated peroxide of
cerium reddens vegetable blues. When heated it melts
into an orange coloured liquid, which becomes yellow when
all the water is driven off. A red heat decomposes the salt
altogether.

20 grs. of this salt were digested in a flask with a large
quantity of distilled water. The solution was perfectly
colourless, but a yellow powder remained at the bottom.
It was collected on a filter, well washed with boiling dis-
tilled water, and dried. It weighed 2*7 grs., but after expo-
sure to the highest temperature of the sand-bath, it was
reduced to 2*362. By analysis it was found a disulphated
peroxide of cerium composed of .

Peroxide of cerium . . 1*742
Sulphuric acid .... 0*621

2*363
The residual colourless solution was reduced by evapora-
tion to a convenient bulk, and boiled in a flask with a solu-
tion of carbonate of ammonia. The precipitated carbonate
of cerium, after being well washed and dried, weighed 8*9
grs., and after ignition the weight was 5*33 grs.

The residual solution, after being mixed with nitric acid
in excess, was precipitated by chloride of barium. The
sulphate of barytes, after washing and ignition, weighed
19*95 grs. = 6*87 grs. of sulphuric acid. This analysis
gives us,

Peroxide of cerium . . 5*33 or 7*072 - 1 atom.
Sulphuric acid . . . 6*87 ,, 7*491 - 1 J atoms
Disulph. peroxide . . 2*362,,
Water ...... 5*438,, 5*438 - 5 atoms.

20*
Thus, it appears that the salt was a sesquisulphated
peroxide of cerium containing 5 atoms of water.

3. Disulphated protoxide of Cerium. — A white insoluble
powder obtained when the sulphate of cerium is thrown
down by ammonia. It is composed of,

Protoxide of cerium . . 13* or 2 atoms.
Sulphuric acid .... 5* ,, 1 atom.
Water 2*1 ,, 2 atoms.

1835.] Chemical Analysis of Gadolinite, Sfc. 421

4. Disulphated peroxide of Cerium. — A sulphur yellow, in-
soluble powder, obtained by dissolving sesquisulphated per-
oxide of cerium in water. When heated it becomes white,
and reddish by a gentle ignition. Before ignition it dis-
solves easily in acids, but after being heated to redness it
is not acted on by nitric, muriatic, or nitro-muriatic acids.

2*18 grs. of the yellow salt were dissolved in a flask with
muriatic acid. Carbonate of ammonia was then added, and
the mixture boiled. The precipitated carbonate collected
and well washed, left, after ignition, 1*28 grs. of peroxide
of cerium.

The residual solution mixed with nitric acid gave 1*305
grs. of sulphate of barytes = 0*45 sulphuric acid. This
analysis gives us,

Peroxide of cerium . . . 1*28 or 14-4
Sulphuric acid . . . . . . 0*45 ,, 5*

Water 0*45

2-18
As nearly 2 atoms of oxide as could be expected from an
analysis on so small a scale.

5. Potash-sulphate of Cerium. — A granular white powder,
scarcely soluble in water, but easily so when a little acid
is added.

18*9 grs. of the salt, previously gently ignited, were
dissolved in a flask in dilute muriatic acid. Carbonate of
ammonia was then added ; the mixture was boiled, and
filtered while boiling hot. The carbonate of cerium, after
being well washed, weighed 9*5 grs. reduced by a strong
ignition to 6*00 grs. peroxide = 5*57 grs. protoxide.

From the residual solution, mixed previously with nitric
acid, the sulphuric acid was thrown down by barytes. The
ignited sulphate weighed 23*467 grs. = 8*23 grs. sulphuric
acid.

The residual solution, the excess of barytes having been
removed by sulphuric acid, was evaporated to dryness and
ignited, mixed with carbonate of ammonia and again
ignited. The sulphate of potash remaining, weighed 9*53
grs. — 5*20 grs. of potash. This analysis gives,

Protoxide of cerium . . 5*57 or 6' 5 - 1 atom.

Potash 5*20 „ 6*06 - 1 atom.

Sulphuric acid .... 8*23 „ 9*6 - 2 atoms.

422 Dr. Thomas Thomson and Dr. Steel's [June

A little sulphuric acid may have been driven off by the
previous ignition. The result is, however, sufficiently near
to prove the composition of the salt to be,

1 atom sulphate of cerium . . 11*5
1 „ „ potash . . 11*0

22-5

6. Potash-sesquisulphated peroxide of Cerium. — A beautiful
yellow powder, becoming white when washed or heated.

4*8 grains lost by gentle ignition 0*5 grs. The residue
was dissolved in muriatic acid, and the oxide of cerium was
thrown down by ammonia. The remaining liquor evapo-
rated to dryness, left 1*8 grs. of sulphate of potash.
It is clear from this that the salt is a compound of,
1 atom sesquisulphated peroxide of cerium,
1 atom sulphate of potash.

7. Oxalate of Cerium. — This salt may be obtained by
adding either oxalic acid or oxalate of ammonia to a solu-
tion of sulphate of cerium. When oxalic acid is used the
salt falls down like a piece of curd, perfectly white, and it
may be taken out of the vessel in a lump on the end of a
glass rod. It is very adhesive and plastic, exactly like so
much soft resin. Whether allowed to remain in the solu-
tion or dried, it rapidly loses this property, and falls to a
white powder. When heated it burns and leaves pure per-
oxide of cerium.

After having been dried in the highest temperature it
could bear without charring, 28*15 grs. left, on ignition,
17*9 grs. of peroxide = 16*62 protoxide. Supposing the
salt to have been perfectly anhydrous, we have its com-
position,

Protoxide of cerium . . 16*62 or 6*492 - 1 atom.

Oxalic acid 11*53 „ 4*5 - 1 ,,

28*15

8. Sesqui-oxalated peroxide of Cerium. — This salt may be
obtained from the solution of the peroxide, exactly in the
same manner as the last salt. The adhesive matter obtained
is reddish-yellow, instead of white, but it falls into a white
powder when dried.

20*6 grs. digested in caustic potash for 12 hours left 10

1835.] Chemical Analysis of Gadolinite, fyc. 423

grs. of peroxide of cerium. The weight was not altered by
nitric acid. The residual liquid containing the oxalic acid
was accidentally lost ; but, from the preceding experiment,
we may deduce the composition of the salt as follows : —

Peroxide of cerium ... 10* or 7' - 1 atom.

Oxalic acid 9*57 ,, 6*75 - 1 J atoms.

Water 1*03 „ 0-75 - \ atom.

20-6 ,

9. Disesqui-phosp hate of Cerium — 8*3 grs. peroxide = 7*7
grs. protoxide of cerium were digested in muriatic acid,
and the solution evaporated to dryness. The white matter
remaining after being again dissolved in water was precipi-
tated by phosphate of soda. The white precipitate collected
on a filter, well washed and dried, weighed 12*2 grs., reduced
by ignition to 1 1 *09 grs . Its colour had now become greenish-
yellow. It was hard, compact, and semivitreous, but with-
out tHe least appearance of having been fused.

It is obvious that the constituents of this salt are,
Protoxide of cerium . . 7*70 or 10*22 - 1 J atoms.
Phosphoric acid . . . 3*39 ,, 4*5 - 1 atom.

11-09

10. Disesqui-phosp hated peroxide of Cerium. — 10 grs. of
peroxide of cerium were dissolved in nitric acid, and gently
evaporated to dryness. The red mass obtained was dis-
solved in water, and .precipitated by phosphate of soda. The
precipitate, which was slightly yellow, was collected on a
filter, well washed and dried. It weighed 16*42 grs.
reduced by ignition to 14*23 grs. It had exactly the colour,
lustre, and appearance of the preceding salt.

Its constituents were

Peroxide of cerium ... 10* or 10*63
Phosphoric acid ... 4*23 ,, 4*5

This is obviously 1J atoms of peroxide of cerium, and
! atom phosphoric acid. Thus, in its constitution, it agrees
with the former salt. The only difference between them
being the different states of oxidizement of the cerium.

The preceding experiments were made with a view of
determining the atomic weights of yttria and cerium with
more accuracy than could be done formerly, when the

424 Dr. John Mutters Examination of [June

experiments were made upon only a few grains of each.
The specimen of gadolinite employed weighed several
ounces, and enabled us to procure such quantites, both of
yttria and oxide of cerium, that we were enabled to repeat
our experiments till we satisfied ourselves of their near
approach to accuracy. The preceding account contains the
most material facts which we ascertained. The experiments
themselves occupied several months, and would have occu-
pied a great deal of room had Ave thought it requisite to
detail them at full length.

Article III.

Examination of Lymph, Blood, and Chyle. By John Muller,
M.D. Professor of Physiology in the University of Bonn.
(Poggendorff's Annalen, Band xxv. 513.)

In the winter of 1831-32, a favourable opportunity occurred
at Bonn for examining human lymph. Professor Wutzer
had a young man under his care with a wound of some
standing on the upper part of the foot. When pressure was
made on the back of the great toe, in the direction of the
wound, a clear liquid spouted out, which was lymph. In
the course of 10 minutes it deposited a cobweblike coagulum
of nbrine. According to Reuss, Emmert, Sbmmering, and
other late observers, the lymph contains no globules.
Hewson, however, in the lymph from the thymus gland of
the calf, discovered numerous white globules, and in the
reddish lymph of the spleen, red globules. Dr. Nasse and
Hrn Muller, by means of the microscope, appear to have
established the same fact in reference to human lymph. In
clear, transparent lymph, they observed a number of colour-
less globules, which seem smaller and less abundant than
the globules of human blood. Part of these globules is
included in the coagulum, but the greatest portion remains
suspended in the serum of the lymph. It is to be remarked
that the coagulum is not formed by the accumulation of the
globules, but it may be easily perceived that a substance
previously in solution coagulates, and takes up part of the
globules. These globules may be more distinctly seen in
the coagulum, when a small portion of the lymph is placed

1835.] Lymph, Blood, and Chyle. 425

in a watch glass, and allowed to stand. The glass magnifies
the globules, and permits their presence to be demonstrated.
The substance which unites the globules may be observed
on the edge of the coagulum to be homogeneous, slightly
translucent, and does not appear to consist of globules, but,
if globules are contained in it, they must be greatly inferior
in size to those of the lymph. These observations shew
that although the lymph contains globules suspended in it,
yet the fibrine is held in solution.

It is more easy to obtain lymph from the inferior animals
for the purposes of experiment than it is to procure human
lymph. Pure lymph can be collected in considerable quan-
tity from a large frog, by separating the skin from the
muscles, with the precaution of avoiding to injure the
blood vessels. A liquid flows out which deposits a coagulum
when placed at rest for a few minutes. In 81 parts of the
lymph of the frog is contained 1 part of dry fibrine. Coa-
gulation is prevented by allowing the frog to fast for a long
time before collecting the lymph. Fresh lymph from the
frog contains globules, thinly scattered through it. These
are round and smaller than the elliptical globules in the
blood of the frog.

According to the experiments of M tiller, by the addition
of a concentrated solution of caustic potash, albumen is
separated not only from the lymph of the frog but also
from the chyle of mammalia, and from small quantities of
the serum of the blood. Lymph is generally colourless.
Hewson, Tiedemann, and Gmelin, have remarked that it is
often reddish in the lymph vessels of the spleen, which
Rudolphi considered accidental. Hewson attributed this
colouring to the presence of the red globules of the blood,
an opinion which must be received cautiously, because,
under the microscope, the globules of the blood do not
at once appear red.

Little is known with regard to the mode in which the
lymph is carried into the circulation, for no contraction has
hitherto been detected in the lymphatic ducts. Mtiller,
however, has observed in the frog a double contractile
organ, lying on each side behind the hip joint, on the side
of the rectum, in the ischiatic region, which appears to have
great influence on the propulsion of the lymph. The

426 Dr. John Mailers Examination of [June

rythmus of the contraction of this organ is peculiar, being
neither synchronous with the heart nor respiration, nor with
each other, and can be readily perceived when viewed pos-
teriorly through the skin, and very distinctly when the skin
is removed . Under this organ lie a large vein and artery,
whose circulation, however, has no influence upon the
organ. The organ itself is oblong, and contains a clear
colourless liquid, which flows out when an incision is made ;
and if we inflate it downwards, not only are the vessels of
the thigh and leg filled, but likewise some of those of the
trunk. When inflation is made upwards a lymphatic duct
leading to the back is filled. It may be remarked, that by
inflating the organ, the whole veinous system, as well as
the lymph vessels, are filled with air, which would go to
demonstrate the existence of an intimate connexion between
these two sets of vessels. The same lymphatic apparatus
was detected in the toad, similarly situated as in the frog,
and in the salamander and green lizard, on the side at the
root of the tail, close behind the extremity of the rectum.
Dr. Marshall Hall has described a peculiar structure situ-
ated near the tail of the eel, which serves as an auxiliary to
the heart, and performs a regular diastole and systole,
quite distinct from that organ. Miiller, aware of this dis-
covery, examined the eel, and found, at the point of the
tail, a pulsating organ containing a transparent reddish
liquid, which was carried forward into a canal lying on the
inferior side of the tail. On injecting the organ a number
of large vessels were filled with the mercury on the same
side on which the incision for introducing the injecting
liquid was made. The soft fins were likewise reached by
the mercury, and their rays presented the appearance of
parallel canals. A principal canal 1| line in diameter, cor-
responding with one on the upper side, lies on each side of
the inferior surface, at the insertion of the fins, and between
them are numerous small longitudinal vessels and transverse
branches. Each of the vessels connected with these organs
must be injected from their own side, either through the
organs or by the longitudinal canals.

About the end of the gut the lateral canals on the under
side appear to communicate on both sides with each other.
The organ itself is obviously double, for pulsation is observed

1835.] Lymph, Blood, and Chyle. 427

on one side while it has ceased on the other, in consequence
of an incision.

Future experiments must determine whether or not the
use of this organ is to propel the lymph of the tail into the
extremity of the caudal vein.*

ON THE GLOBULES OP THE BLOOD.

The form of the globules of the blood has been differently
stated by almost every observer. Miiller, in employing an
excellent microscope for the purpose of examination, found
that they must not be viewed through the medium of water,
because that liquid instantly alters their form, and converts
elliptical globules into round ones. The best liquid to
employ is serum, or the globules may be diluted with water
holding in solution common salt, or sugar, which does not
affect their shape. Miiller attributes the various results of
different observers to their diluting the blood with water,
and to the employment of bad instruments. In man, the
globules were found to be generally equal, with occasional
larger ones. The globules of the frog were also equal,
but mixed with some of a smaller size. In the embryo
of the coney they are destitute of uniformity, but as the
animal advances they become more equal. In the larva of
the frog they appeared somewhat smaller and paler than in
the mature state of the animal. The form of the globules
varies in different animals, from circular to elliptical, but
they are always flat. In men and mammalia they are
circular; elliptical in birds, (domestic fowl and pigeon,)
amphibious animals, (frog and lizards,) and fish, where they
also approach a round form, especially in the carp. Miiller
has satisfied himself that the globules are flat, by a careful
examination of the blood, not only of those animals men-
tioned, but also of the calf, cat, dog, and rabbit. The long

* In addition to the two posterior lymphatic hearts of amphibia, Miiller has
lately discovered two anterior analogous organs, and has described them in the
Phil. Trans, for 1833, part i. 92. They lie on each side, upon the great transverse
process of the third vertebra, and are easily detected when the scapula is carefully
raised and partly cut away. They are of a round shape, and pointed anteriorly
where they are connected with the jugular vein on their respective sides. If these
organs be incised and inflated, lymphatic spaces in the axilla become filled with
air, and when injected upwards with mercury, the jugular vein as far as the supe-
rior vena cava, is filled. — Edit.

428 Dr. John Mutter's Examination of [June

diameter of the globules in men is four or five times greater
than the broad diameter, and in the frog eight or ten times
more extensive. Of the animals examined by Miiller, they
are smallest in men and mammalia, (among the latter the
goat possesses the most minute globules, according .to
Prevost and Dumas, a fact which is confirmed by Miiller,)
a little smaller in the calf, largest in the naked amphibia,
and inferior in size in birds, fish, and scaly amphibia. In
man their broad diameter was found to be 0*000245 —
0-000373 English inch. The globules of the blood in birds
are half as large as those of the frog, and of the latter
animal the globules are many times larger than in man.

In the centre of the globules a spot may be detected,
round or elliptical, according to their form, which by
reflected light appears clear, and by transmitted light,
dark. Dr. Young considered this a cavity. When the
globules are held obliquely, so that part of one side is seen
and part of the upper edge, a dark semi-circle is formed by
the upper edge, the interior surface of which is convex and
the other concave. According to Miiller the globules of
the blood in the frog and lizard contain a nucleus, which
differs in chemical composition from the external substance
surrounding it. The same nucleus he detected in fishes
and birds, and in man he observed a very small round
substance, yellower and brighter than the transparent
matter which surrounded it. When the globules are placed
in acetic acid under the microscope, the exterior coat is
observed to be dissolved, leaving the nucleus in an isolated
state, which in the human blood it is very difficult to see,
but in the blood of the frog is very distinct. In the blood
of the frog a smaller kind of globules occur, which are
completely round, not flattened, and are much more minute
than the elliptical globules.

Miiller conceives that the nuclei of the elliptical globules
may consist of the lymph and chyle globules, an opinion
which seems to be strengthened by the circumstance that the
chyle globules are completely insoluble in water, but that
the globules of the blood are soluble as far as the nuclei,
which are insoluble. As long as they are contained in the
serum their colouring matter is insoluble, but when they
come in contact with water the colouring matter is dissolved.

1835. Lymph, Blood, and Chyle. 429

In blood extracted from men and cats, half an hour scarcely
elapses before the globules sink 4 or 6 lines beneath the
surface of the serum, while in that from oxen and sheep
an interval of 12 or 24 hours occurs before the globules
have subsided a line and a half.

If water, however, is added to blood extracted from mam-
malia, a portion of the colouring matter dissolves in that
liquid, and a great proportion of the globules sinks to the
bottom. In the blood of the frog the globules sink so
rapidly that it is necessary to stir up the coagulum in order
to have the globules mixed with the serum for the purposes
of examination. When water is added to a mixture of
serum and globules, and agitation employed, the colouring
matter of the globules dissolves, and a light coloured preci-
pitate falls to the bottom of the vessel, which appears under
the microscope to consist of roundish globules, much smaller
than those of the blood. This residue, from the action of
water, is soluble in alkalies, but insoluble in acetic acid.

That the colouring matter of the globules is completely
soluble in water, and is not suspended in that liquid, may
be easily demonstrated, not only in human blood and in
that of mammalia, but also more readily in the blood
globules of the frog. Berzelius considers the insolubility
of colouring matter in serum to depend on the presence of
albumen. M tiller, although he agrees in considering the
colouring matter of the globules soluble in water, does not
attribute the insolubility of the colouring matter in serum
solely to the presence of albumen rendered soluble by soda,
but more especially to the salts of the serum. When he
placed under the microscope a drop of the blood of the frog,
mixed with a drop of a solution of the yolk of an egg in
water, he observed the blood globules change their form as
rapidly as when he employed pure water. But when a
drop of the same blood was joined with a solution of carbo-
nate of potash or common salt, the form and size of the
globules was not altered.

Water renders the globules smaller than the long dia-
meter of the original ellipse, but larger than the broad
diameter. But water containing carbonate of potash, or
common salt, sal-ammoniac or sugar, in solution, produces

430 Dr. John Muller' s Examination of [Junk

not the slightest change in their shape and size. In a
saturated solution, however, of carbonate of potash, they
appear by degrees to become somewhat smaller.

When the globules have been treated with acetic acid
the nuclei remain, varying in form in the blood of different
animals. In the frog these nuclei appear not to be flat, or
at least, not perceptibly so. In the salamander they are as
distinctly flat as the globules themselves. The nuclei,
when their external coat has been removed by acetic acid,
have a brown colour, which appears to depend upon some
colouring matter still adhering to them, for when treated
with water they are white.

Hydro-chloric acid does not completely dissolve the outer
coat of the globules, although it renders them sensibly
smaller. Chlorine changes the colour of the blood of the
frog, first causing it to assume a brownish hue, and then a
whitish colour. Tincture of nutgalls, liquor stibii muriatici,
and liquor mercurii muriatici corrosivi cause the globules to
shrink.

A dilute solution of muriate of iron produces no change
in the globules.

Caustic potash does not change their form, but speedily
dissolves completely both external coat and nucleus.

Caustic ammonia dissolves them more rapidly, and when
brought in contact with them makes them round.

Alcohol does not alter the globules.

Strichnin and Morphia are also inactive.#

The globules both in the arterial and veinous blood are of
a similar shape and equal size, and Muller has not been
able to detect any difference between the globules in the
veins of the lungs of the frog and those of the body. He
examined the effect of oxygen and carbonic acids upon the
blood, in a tube over mercury. The former changed the
blood of the frog to a brighter red, the latter made it very
dark, and of a dirty violet colour.

* Raspail states that hydro-chloric acid completely dissolves the glohules.
Ammonia and concentrated acetic acid have the same effect. Heat and alcohol
coagulate them. If his observations are correct, although they are at variance
with those of Muller, the globules must obviously consist of albumen. He affirms
that blood may be simulated by the spontaneous evaporation of a menstruum
containing albumen in solution and the addition of colouring matter. Nouveau
Systeme de Chimie Organique, 8vo. 1833, p. 370. — Edit.

1835.] Lymph, Blood, and Chyle. 431

FIBRINE IN HEALTHY AND DISEASED BLOOD.

The usual explanation of the coagulation of the blood is
that it is produced by the aggregation of the globules, and
that the nuclei of the globules consist of bodies formed
of fibrine, surrounded by a coat of colouring matter.
Home, Prevost, and Dumas, have supported this view, and
Dutrochet came to the same conclusion in his galvanic
experiments.

Berzelius has conjectured, from the circumstance of the
lymph containing fibrine in solution, that the blood also
possesses fibrine dissolved in it, and that the lymph may
be a fluid filtered from the blood.

Muller considers that he has established the truth of this
conjecture, and has proved that the red coagulum is formed
by a quantity of fibrine and globules of the blood, the fibrine
being previously dissolved in the blood. For, when the
blood of the frog is placed in a watch glass, before the for-
mation of the whole coagulum, a clear thick matter may
be extracted from the glass by means of a needle. If the
serum be filtered through common white filtering paper,
diluted with water, the globules are detained, and within a
minute a colourless coagulum appears in the liquid, which
passes through the filter so extremely transparent that its
presence is scarcely detected till a needle is introduced for
the purpose of raising it.

It gradually becomes whitish, and resembles the coagulum
observed in human lymph. For the purpose of this experi-
ment it is necessary to use paper which has been previously
ascertained to allow the serum to pass without the globules,
and pure blood must be employed, obtained directly, by
incision, from the heart of the frog. When acetic acid is
dropped into the filtered serum, the fibrine does not appear,
but remains in solution. Caustic potash prevents the fibrine
from collecting in a mass, but retains it in the form of small
flocks, which are more distinctly seen when the liquid is
dropped into a watch glass filled with sulphuric ether.
The albumen of the serum is thrown down in a similar
manner. Dilute caustic potash does not precipitate the
albumen from the liquor of the blood, but concentrated
potash readily effects its precipitation.

432 Dr. John Mutter's Examination of [June

Caustic ammonia throws down albumen from the liquor
of the blood, and also from the solution of the white of an
egg. Caustic potash does not precipitate albumen from
the egg, whereas the liquor of the blood will always be
acted upon when small quantities of serum are added to
large portions of caustic potash . In milk also the coagulable
constituents are thrown down by a quantity of caustic pot-
ash, and the same circumstance occurs with regard to chyle,
although milk is very different in its characters from chyle.

According to Tiedemann and Gmelin, and also Miiller,
the albumen of the egg is coagulated by ether, but that of
the serum is not altered. The fibrine dissolved in the serum
is easily distinguished from the albumen, in the same fluid,
because the former coagulates of itself, while the albumen
is only rendered solid by re-agents, by a particular tempera-
ture, and by the galvanic battery ; and farther, according
to Miiller, ether coagulates the fibrine of fresh blood, but
not the albumen.

Prevost and Dumas have endeavoured to estimate the
quantity of the globules of the blood of different animals
separately from red coagulum. Berzelius has observed,
however, that these experiments cannot be very accurate ;
because the coagulum retains a quantity of serum, which,
by drying, will be deficient in albumen and salts, while the
washings will contain not only serum but also a portion of
the red constituents of the blood.

Berzelius says that when blood is kept for several days,
the red globules sink, and the serum sometimes becomes
reddish, in consequence of a small portion of the colouring
matter being dissolved. The experiments of Muller decid-
edly contradict this statement ; for he has examined with
two different powerful microscopes the blood of the calf,
of oxen, of man, and the cat, and as long as water was
prevented from coming in contact with the blood he could
not observe the slightest alteration in the form and size of
the globules.

In the blood drawn from man and cats the globules sank
in 12 hours 5 or 6 lines below the surface of the serum.

The globules of the blood in the frog sink rapidly to the
bottom of the vessel. Muller, in making some quantitative
experiments on the blood of the ox, obtained from 3627 grs.

1835.] Lymph, Blood, and Chyle. 433

18 grs. of dry fibrine ; and 39*45 grs. of the same blood
yielded 6*41 grs. of dry red coagulum, which affords a per
centage of 16*248 of dry red coagulum, the latter containing
0*496 fibrine.

(To be continued.)

Article IV.

Experiments and Observations on Visible Vibration.

By Charles Tomlinson, Esq.

( Continued from p. 367. )

Note. — The following paragraph, which seems to have been
passed over in copying, should have been inserted in the
preceding paper at p. 363.

16. If two unisonant glasses containing mercury be
employed, a faint impression of the undulae can be observed
in the second glass while vibrating the first. So also if the
circumference of the mercury in the second glass be sur-
rounded with shot, the vibration of the first glass will set
the shot in motion. If the vibration of the first glass be
suddenly interrupted by placing the hand upon it the second
glass will continue to yield the same note, and the shot will
vibrate for some seconds, in accordance as it were, with the
fundamental note.

47. There is, perhaps, no music more sweet, or any that
appeals more perfectly to the feelings than that produced
by musical glasses. In the course of these experiments
I had accumulated a great number of glasses, and it oc-
curred to me that a set might be easily and cheaply arranged.
Out of about thirty glasses that I had by me, I only met
with five that answered my purpose : three soda water
glasses, yielding the notes B flat, D and E within the stave,
and two smaller ones yielding the notes G and A in alt. I
accordingly sent for glasses at different times, to the amount
of about a hundred, or a hundred and fifty. I ranged about
a dozen at a time on a smooth mahogany table, and sounded
the notes required on a flute, resting the end on the table, so
that any of the glasses in accordance with the note sounded
sympathetically ; if none accorded all were silent. By this
means I became not only sure of a perfect instrument, but

vol. i. 2 F

434 Mr. Tomlinsons Experiments and [June

spared myself the trouble, and what to me was of most con-
sequence, the time of testing each glass separately. This
method also is superior to that depending on a musical ear,
however good it may be. Thus, I completed two octaves,
together with four of the most useful semi-tones, and
arranged them in a deal case according to Dr. Arnott's
method, which is a very convenient one. My instrument
allows me to play upwards of fifty popular tunes and
national airs in the key of B flat major; and, in point of
tone it surpasses those sold by the makers, who charge from
twelve to fifteen guineas for two octaves, while mine has
cost me but twenty-five shillings.

48. Dr. Franklin, I believe, contrived the first instrument
and suggested the method of tuning the glasses by means
of water. But this mode is objectionable for several reasons.
The effect of water is to lessen the number of vibrations,
and thus to lower the fundamental note of the glass. By
this means, not only is the natural richness of the note
impaired, but the relative accuracy of the notes can.rarely
be obtained. In warm weather I have known an instru-
ment get out of tune in a few hours simply by the evapora-
tion of the water. A patent was, I think, taken out some
years ago to remedy this defect. The patentee dispensed
altogether with water, and coated the belly of the glass
with a cement which dried and hardened, and thus brought
the note down to the desired pitch. This mode, it will be
seen, is objectionable, as the tone is much deteriorated, and
should any of the cement chip off, which it is not unlikely
to do in using or cleaning, the note becomes immediately
wrong. Another method is to grind the glasses to the proper
pitch, this, however, is both tedious and expensive, and,
therefore, objectionable.

49. By the plan that I propose, (47.) all these objections
are obviated, and a beautiful instrument is obtained, pos-
sessing the great advantage, so well appreciated by the
musical amateur, of being always in tune. It will, how-
ever sometimes happen that a glass may be met with yield-
ing a full sympathetic note, yet when vibrated by the finger
the interference of sound (12.) arising from irregularities
unappreciable to the eye, will be sufficient to exclude it
from the set, but this objection is easily obviated, by having
recourse to another glass.

1835.] Observations on Visible Vibration. 435

50. It is important and interesting to investigate the
changes undergone by a glass during vibration, in order to
obtain more information as to the multiform variety of
vibration in various bodies. I have obtained many curious
results, which I will detail hereafter. In the present paper,
I propose to state the effect of various fluids in modifying
or changing the note produced by the vibration of a foot
glass.

51. It does not appear that performers on musical glasses
tuned by means of water have been aware that a fluid may
be added to a glass to a certain height without perceptibly
altering the note, or its capability of yielding sympathetically

' the fundamental note, and that the quantity of fluid necessary
to modify or change the fundamental note depends upon its
specific gravity. Thus, for example, if a cylindrical foot
glass be taken, the fundamental note of which is the first
C in alt, and that note be sounded on a flute within one or
two feet, the glass will vibrate the same note though it
contain water to the depth of 1^ of an inch, and under.
If, however, that limit be passed, the fundamental note
begins to descend.

52. The glass that I employed as a standard in the fol-
lowing experiments was 3 finches in height, omitting the
foot. I graduated it on the exterior side to twentieths of an
inch, and, in stating my results, I shall, for the sake of
convenience, adhere to the vicesimal division of the inch.

53. By this it will be seen that there is a line passing round
the glass latitudinally , which line I propose to call the axis of
vibration, a point on which the fundamental note of the
glass seems to turn. There are other lines which I have
succeeded in tracing which will be described hereafter ; my
present purpose is with this one particular line.

54. This line is probably fixed and invariable in the same
glass, but it appears to rise and fall in proportion to the
specific levity and gravity of the fluids employed. It is, I
believe, confined to the interior of the glass, for I incline to
think that active or positive vibration is confined to the
interior of a glass, the exterior being negative.* The

* This, together with other changes undergone by a glass during vibration,
will form the subject of the next paper, wherein, the producing cause of the cur-
rents of mercury, and their action, will also be further considered.

2f2

436

Mr. Tomlinsoris Experiments and

[June

action of a fluid of great specific gravity in a glass is to
neutralize the parts of the glass in contact with that fluid.
Mercury does so very perfectly, water in a manner less
perfect, and ether still less perfect, and so on.

55. The following results were obtained when distilled
water at 60° was employed : —

J.a:is 1^ iwc^.

1#

inch — B

Hi

B flat.

2A

„ A

2&

,, G sharp.

m

„ G

21*

,, F sharp.

2^

„ F

3

„ E glass full within -^

inch.

56. Pure mercury was next employed with the following

results : —

Axis ±& inch.

1 6 inpti

2 o llLK*11

B

1-H- inch C

1

Bflat.

lxs.
20 »»

B

1 2 0 >»

A

2 „

B flat.

1 2 0 p

G sharp.

*-£o >»

A

I20 »»

G

A2 0 >»

G sharp.

1 20 ?»

F sharp.

2 -±-

^2 0 »>

G

* 2 0 >>

F

^A »>

F sharp.

*20 "

E

2-8-

F

1X2.

D sharp.

2^J >>

E

IXi.

*20 "

D

^20 >>

#D sharp.

1X5.

X20 "

C sharp.

9x2.
^20 »>

*D

2-J-J inch #C sharp.

oxl

A2 0 >»

C the lowest no

te on the flute.

2^-J- ,, B tried by the octave above.

(Those notes marked with a star were produced by
striking the glass with a wooden hammer covered with
leather.)

57. The large number of notes obtained from the glass
when mercury was employed surprised me. I have before
stated (21.) that a fluid in a glass raises, as it were, the
bottom of that vessel. This remark, however, is not strictly
true, but the effect is best obtained when so heavy a fluid
as mercury is employed. The vibrations being neutralized
from the surface of the fluid downwards ; whereas, with the

1835.]

Observations on Visible Vibration.

437

other fluids, the neutralization only decreases from the
surface of the fluid downwards ; so that, in order to obtain
the same number of notes from water as from mercury,
it would be necessary to employ a glass about three times
as high.

58. Before I proceed further it maybe necessary to state
my method of conducting these experiments. The same
graduated glass (51.) was employed throughout, fixed on a
level plane, and the results, generally speaking, noyaken
until the glass yielded the descending notes sympathetically
responsive to a flute. The glass was carefully washed, and
wiped dry at the end of each experiment, and the specific
gravity of each fluid was taken immediately before it was
employed. I have gone twice over these and the two pre-
vious (55, 56.) experiments. In the first trial my pupil, Mr.
Whitchurch, sounded the flute, and in the second, Mr. Ayl-
ward, a professor of that instrument, a gentleman on whose
correct musical ear I can implicitly rely.

59. The following liquids were successively employed in
the order of their specific gravities, as follows : —

Sp. Gr. .

1. Sulphuric acid . . . 1*852

2. Nitric acid . .

. 1-351

3. Muriatic acid

. 1-139

-

4. Pyroligneous acid

5. Castor oil . .

1-044
0-957

6. Linseed oil . . .

0-933

7. Oil of turpentine .

8. Pyroligneous ether

9. Oil of olives . . ,

0-871
0-856
0-810

1. SULPHURIC ACID.

Axis 1-^ inch.

1-& inch B
1« „ Bflat.
li$ » A

2 gV »> Cr sharp

& » 2 ;

2^ » F sharp.

2^ inch

9XJL

OJLfi.
*20 >>

2-Jls.

F
E
D
D
C

sharp,
sharp.

438

Mr. Tomlinsoris Experiments and

[June

l£J inch B

x 20

2ft
2ft

Bflat

A

G sharp.

G

2. NITRIC ACID.

Axis lft zwc^.

m
m

inch F sharp.

„ F

„ E

„ D sharp.

3. MURIATIC ACID.

Axis 1ft £«C^.

tyf inch I

^2 ir

inch G

1« M

Bflat.

p

„ F sharp.

2ft „

A

m

» F

"ft „

G sharp.

m

„ E

4. PYROLIGNEOUS ACID.

Axis 1ft zwc^.

1|J inch B

^"20

inch G

2 4 "

Bflat.

Ol"6

*5#

„ F sharp

2ft >>

A

»H

„ F

^o" »>

G sharp. i

»A

„ E

5. CASTOR OIL.

Axis 4§ inch.

1ft inch ]

912

inch G

*W "

Bflat

9*5

^20

,, F sharp

"ft >»

A

919

» F

2ft >?

G sharp.

6. LINSEED OIL.

J.;m 1ft inch.

1-JJ inch :

914

inch G

HS 5>

Bflat.

91 7

,, F sharp

^2 0" >>

A

3

„ F

O10

G sharp. J

HJ inch B

lit » »««*.

2ft >? A

2J$ „ G sharp

7. OIL OF TURPENTINE.

^.a;w 1ft inch.

211 inch G

, F sharp.

. F

2f

1835.] Observations on Visible Vibration. 439

\jfi inch B
2A „ B flat

8. PYROLIGNEOUS ETHEE.

Axis l^y inch.

2\l inch G sharp,

m „ G

Vn »i A 2JJ „ F sharp

9. OIL OF OLIVES.

Axis 1

ft £rac/*.

1« inch B

2-±§ ineh G sharp

2A » Bflat-

2M- „ G

2& m A

2JJ „ F sharp.

Brown Street, Salisbury,

28th April [$35.

Article V.

On the accidental Colours of certain solutions on Mercury.
By Charles Tomlinson, Esq.

To the Editor of the Records of General Science.
Dear Sir,
In the course of my experiments on Visible Vibration, I
noticed a ready and convenient method of observing acci-
dental colours without fatiguing the eye, which was new to
me, and will, I hope, prove interesting to some of the
readers of your Journal.

Having occasion to diminish somewhat the reflecting
surface of mercury contained in a foot glass, I poured about
an ounce of a solution of litmus, which had become slightly
reddened by exposure to the air, upon the surface of the
mercury, when the upper portion of the glass above the fluid
was reflected twice, the lower reflection by the mercury and
the upper one by the litmus solution. On placing the fin-
ger on the periphery of the glass, and bringing one eye near
to another part of the periphery, two reflections of the fin-
ger were seen ; one the colour of the litmus, a beautiful
purple inclining to red, and the other a delicate light green
its accidental colour.

On adding a few drops of nitric acid to the litmus solu-
tion, the accidental colour was of a dark and decided green.

With mercury and a solution of chromate of potash a fine
blue accidental colour was obtained.

440 Mr. Tomlinson, on Colours, fyc. [Junk

With muriate of lime the same result was obtained with
this addition ; on looking steadfastly into the glass with one
eye, the other being closed, a variety of white spots began
to form on the iris, giving the eye an unpleasant mouldy
sort of appearance. The aqueous humour seemed to con-
sist of one isolated drop of water, so distinct from any other
part of the eye, that it seemed as if it would have dropped
down into the glass ; in a short time the transparent mem-
brane covering the pupil became milky, and the glass and
fluids indistinct. I have repeated this experiment with the
same results, except that the white spots on the iris were
not so numerous.

With a deep blue solution on mercury obtained by indigo
in sulphuric acid, the accidental orange-yellow was obtained.

These accidental colours are neither modified nor changed
by the reflection of various coloured solids, such as blue,
yellow and green balls, &c, the accidental colour belong-
ing to the upper fluid and not to the object reflected. In
order to obtain them, however, two liquids of different den-
sities must be employed in order to obtain two reflections,
and for the lower fluid nothing is so convenient as mercury.
Indeed, I have not as yet met with any other fluid that at
all answers the purpose.

The effect is very beautiful with litmus solution and mer-
cury when the flame of a candle is employed ; the two re-
flections have the appearance of hollow cones placed above
and within each other, the lower flame being the accident.

With muriate of lime the lower flame reflected by the
mercury was of a decided yellow, but the accidental colour
of a very faint blue ; whereas, by natural light the acci-
dental is of a fine indigo.

The green flame obtained by boracic acid in alcohol pre-
sents a very fine appearance with litmus and mercury. A
watch glass should be employed supported on a ring formed
out of a piece of wire, and other lights in the room extin-
guished.

Yours, Dear Sir,
very sincerely,

CHARLES TOMLINSON.

Brown Street, Salisbury,
April 22, 1835.

1835.] On Malt. 441

Article VI.

On Malt. By Robert D. Thomson, M. D.

At a time when so much excitement exists in regard to the
subject of Malt, it will not, perhaps, be considered a super-
fluous undertaking if I attempt to lay before my readers
an outline of the process to which grain is subjected before
it acquires this designation.

A knowledge of the peculiarities of this interesting pro-
cess is important in a double point of view, because it affords
a remarkably beautiful specimen of the chemistry of nature,
and because its product forms a staple commodity of British
manufacture, no less than forty millions of bushels of malt
being annually consumed in the United Kingdom, which,
at 60s. per quarter, exceeds in value the large sum of
£ 24,000,000, and contributes a revenue to Government at
2s. Id. per bushel of more than £5,000,000 per annum.

It would throw no light upon the chemical nature of
malting if we were to endeavour to investigate the history
of its discovery, because the changes which grain under-
goes during the stages of the process, are not yet fully de-
veloped ; and we are, therefore, led to infer that the intro-
duction of this preparatory step to fermentation was the
consequence of some accidental observation.

It is sufficiently well known indeed that the method of
inducing the vinous fermentation was understood at a very
early period. Thus the Chinese distil samshoo, an ardent
spirit, (and we are sure that any practice which exists among
them is of very high antiquity) from rice and the roots of
plants, and the savages of the Pacific Ocean prepare a simi-
lar product from the masticated roots of herbs.

The Abyssinians have long been in the habit of ferment-
ing the husks and stones of grapes, and distilling the brandy
which is highly concentrated through a hollow cane called
shambacco.* And the Germans, at the earliest period to
which their history carries us, were so partial to fermented
liquor, that they believed if they obtained the favour of
their divinity (Woden) by their valour, they should be
admitted after their death into his hall, and reclining on

* Pearce's Travels, i. 237.

442 Dr. R. D. Thomson June

couches, should regale themselves with beer from the skulls
of their enemies whom they had slain in battle.#

But for these objects malting is not necessary, for even
in this country much spirit is made from raw grain. The
quantity of grain consumed in this way amounted, in 1834,
to 6,694,344 bushels.

We may consider the subject, first in reference to its
physical nature, or the process of malting, and secondly in
an economical point of view, or the duty on malt.f

I. PROCESS OP MALTING.

Any kind of grain may be converted into malt, but in
this country there are three species of plants belonging to
the order Cereales which are peculiarly employed for this
purpose. These are Hordeum distichum, H. vulgare, and
H. hexastichon.

1. The H. distichum is what is commonly termed barley, %
and is characterized by having two lateral rows of seeds
which are imbricate. The average length of a seed is 0*343
inches. Breadth 0*143 inch. Thickness 0*108 inch.

2. H. vulgare Linn, in herb. Errh. PL Off. 421. Herb.
Davall. 1802, described by Lihneus as having two rows of
seeds more distinct, but there are two additional imperfect
ones, The length of a spike of average grain is 3 inches.
Length of a seed *375 inch. Breadth 0*16 inch.

It is to this species that the name bigg, I believe, is more
peculiarly applicable. The term is one employed by the
country people in Scotland, who are not in general, as
elsewhere, very precise in their definitions, and are apt to
apply one term to different species. Indeed, the whole of
the species are often indiscriminately called bear, a mixture
being often sown which is termed blended bear.

3. H. hexastichon, Linn. Spec. Plant. 125. Hort. Ups. 23.
This species is described by Linneus as possessing univer-
sally hermaphrodite flowers, with the seeds placed regularly
in six rows. The seeds in my specimen were in length 325
inch, in breadth *15 inch, and much inflated and rounded

* Hume's History of England, i. 31.

t See Papers presented to the House of Commons in 1799, 1804 and 1806.

% Through the kindness of my friend Mr. Don, I have had an opportunity of
identifying this and the following species with the specimens in the Linnean
herbarium.

1835.] On Malt. 443

on the external surface. Length of the spike 1*7 inch.
I have been favoured with the authority of an extensive
farmer for identifying this species with the Scotch bear.
" Bigg" says he, " has four rows on the head, two of which
are better than the others and contain also more grains.
Bear has six rows, is a strong coarse grain and may be easily
known after separation from the straw, by its thick husk
and long awn." The first of these distinctions may be a
tolerable criterion, but the latter is decidedly not so, be-
cause in Irish specimens which I possess, the awns of the
H. vulgar e are much longer than those of the H. hexastichon.
It is, therefore, a matter of great doubt whether in all cases
these species of grain can be distinguished after separation
from the straw.

The correct discrimination of these species is of great im-
portance, because the quality of the malt is inferior in the
two latter. From the experiments made in 1806 by order
of Government, it appears that the value of barley is to bigg
as 100 to 89 J, taking the mean of the value of English and
Scotch barley as the standard ; but if we consider the Scotch
barley still as of inferior quality to the English, then the
relations will be as in 1806, English barley 100, Scotch
barley 93, Bigg 86; or the m&\t of bigg is 14 per cent, in-
ferior to that of English barley, and 7 per cent, inferior to
that of Scotch barley. Their relative values may, perhaps,
be better appreciated by attention to the product of spirit
derived from each. Thus the quantity of proof spirits per
quarter of each, is exhibited in the following table :

Wine measure. Imperial measure.
English Barley . 20*76 gallons. 17-20 gallons.
Scotch Barley . 20*02 „ 16'70 „

Scotch Bigg . . 18-96 „ 15-72 „

They differ also in respect of weight, so that the quality
may be in some measure detected by this test. The average
weight of each kind of grain is represented as follows :

lbs. avoird. Imperial measure.

English Barley 49*871 per Winchester bushel. 51-444
Scotch Barley 49*754 „ 51*327

Scotch Bigg. 47-352 „ 48-849

From experiments, it appears that the grain does not
lose any weight by keeping. After an interval of six
months, the difference of weight scarcely ever amounted

444 Dr. R. D. Thomson [June

to xfo^j an(* this was generally in favour of the grain
which had heen kept longest.

If we inquire into the natural history of these different
species, we shall be able to throw some light upon the
causes of the difference in the value of their grain.

Bigg and bear are susceptible of exposure to greater
vicissitudes of climate than barley is. They require also
less time to attain to maturity. Thus, the average time
in which they usually remain in the ground is from ten to
fourteen weeks ; while barley lies from fourteen to twenty
weeks. An instance is recorded where the interval between
seed time and harvest, in the case of bear, was only nine
weeks ; and another, on the contrary, where barley was
twenty-six weeks of ripening. Bear and bigg in common
years are malted by the Highlanders, but in those seasons
which are unpropitious for the ripening of oats, they form
the chief article of food. Hence, the legislature have been
induced to charge a duty of 2s. 7d. per bushel on malted
barley, and 2s. only on malted bear and bigg. In 1789
and 1799, which were late years, the whole of the barley
sown in Aberdeenshire was destroyed, a circumstance
which operated so powerfully upon the farmers, that in
1803, little more than 100 quarters were raised, while
from 35,000 to 50,000 quarters of bear and bigg were
produced.

Now, Aberdeenshire consists of 832,000 English acres
and possesses a mean temperature of 41°* 14.

Mr. Forbes Royle observed barley growing on the Hima-
lah mountains, at an elevation of 8000 feet, the mean tem-
perature of the place being 55° F. But some very important
deductions have been obtained by M. M. Edwards and
Colin,* from their interesting experiments upon the ger-
mination of different kinds of grain. They exposed barley,
wheat and rye to a cold equal to that at which mercury
freezes or — 38*6° F. for 15 minutes, and found that their
vegetative powers were not in the least deteriorated. They
ascertained that if barley, wheat, French beans or linseed
were immersed for a quarter of an hour in water at the
temperature of 154°, the power of germination was com-
pletely destroyed, and it was not till the heat of the water
was reduced to 122°, that these kinds of grain after being

* Ann de Scien. Nat. for May, 1834.

1835.] on Malt. 445

immersed in it would vegetate. Hence, in water, 122° may
be considered the highest limit at which it is possible for
barley to grow. But the temperature varies according to
the media through which the heat is communicated. Thus
these seeds if exposed to a temperature above 143J° in
vapour, or 167° in dry air, are deprived of their vegetating
properties. While wheat, barley, oats and rye, when kept
in hot sand possessing a heat of 113°, would not germinate.
Immersion in water of the temperature of 167° for 15
seconds was sufficient to destroy the power of germination
in most instances ; but this invariably occurred, if the ex-
posure to this high temperature was protracted for 5
minutes. The method in which the heat operates in these
cases, appears to be in some measure elucidated by the
researches of Biot, Persoz, and Raspail, who observed that
the temperature 167° is that at which the grains of starch
burst. Hence, it appears, that in dry air barley may be
exposed to a range of temperature equivalent to 205° at
least, and may still retain its germinating powers unim-
paired.

We have two quantitative analyses of barley, one by
Einhof and the other by Proust. The following are their
results. Einhof obtained from Hordeum vulgare.
Starch not quite free from gluten . . 67*187

Volatile matter 9*375

Saccharine matter 5-208

Husk with some gluten and starch . . 6*770

Mucilage 4*583

Gluten 3*515

Albumen 1*114

Phosphate of lime and loss .... 2*248

100*000*

Proust obtained, Yellow resin ... 1*

Gum ...... 4*

Sugar 5*

Gluten 3

Starch ..... 32*

Hordein 55*

100-f

* Gehlen, vi. 83. Thomson's Chemistry, iv. 262.
t Ann. of Phil. xii. 201.

446 Dr. R. D. Thomson [June

In these results we observe considerable differences,
which are to be attributed to th€L mode in which the ana-
lyses were conducted.

Einhof determined the weight of the starch and gluten
together, when they had been deposited from water in
which the meal contained in a linen bag had been kneaded.

The water from which the starch was separated was fil-
tered and boiled; coagulated albumen subsided, and by
evaporation an extract was afforded which was treated with
alcohol. It gave gluten and sugar. These substances were
separated by mixing the alcoholic solution with water and
distilling the alcohol. The gluten fell down, and the sugar
remained dissolved in the fluid. The alcohol left undis-
solved some gum and phosphate of lime. The former was
taken up by water and left the latter in a pure state. The
matter in the linen bag consisted of vegetable fibre, mixed
with a little gluten and starch. The hordein of Proust was
obtained equally well by means of hot or cold water, which
dissolved the starch and left the hordein in an insulated
state. Raspail considers this substance to be the pericarp
of the seed or what we term bran. The propriety of this
opinion is strengthened by the circumstance that there is
very little of it existing in pearl barley. The substances
reckoned by the French chemists as constituents of starch,
viz. amidone, diatase, amidine and dextrine 9 there is strong
reason to consider as products of the analytical operations.*

It is a remarkable circumstance, in reference to the starch
which forms such a principal constituent of the seed of barley,
that it is possessed of a most durable nature when preserved
in dry magazines. This fact is illustrated in a very striking
point of view by some researches of the French chemists. f
In 1817 a depot of barley was discovered in the citadel of
Metz, which had remained closed up from the year 1523,
and notwithstanding that it had remained in this state for
294 years, it afforded excellent bread when converted into
meal. A similar magazine was also recently detected in
some villages destroyed by the Turks in 1526, where the
corn appeared to have lost none of its qualities proper for
forming an essential article of food.

These, though remarkable instances of the capacity which
the starch of barley possesses of withstanding decomposition,

* Records of General Science, i. 196.
t Journ^de Chiui. medicale, i. 63, 2nd. ser.

1835.] on Malt. 447

must yield infinitely in importance to observations which
have been made upon grain preserved in the collections
of M. Passalacqua. That gentleman brought from the ruins
of Thebes, in Egypt, some grain, which, when examined
byD'Arcet, Vauquelin, Bailly, and Fontenelle, was found to
be slightly acid, and to contain its proper quantity of starch,
but no gluten. Raspail subsequently confirmed the accuracy
of these chemists. When Passalacqua sold his collection
of antiquities to the king of Prussia, Champollion found
between the limbs of a mummy (which he recognised as the
remains of Pharoah, son of Marsaroun Mainoute, or priest
of a great tribe attached to the worship of the goddess
Netpha, the Egyptian Rhea mother of Osiris and Isis,) a
small brown compact loaf, surrounding a number of grains
of barley, which had germinated and been slightly scorched.
These seeds, which must have been above 3000 years old,
were examined by M. Julia Fontenelle, who could detect
no gluten in them, but found that the starch, by its action
on iodine, was not impaired in its properties. A little
acid was also present, as was demonstrated by the re-action
on test-paper.

When exposed to the air and moisture, however, starch
undergoes a remarkable change. M. Lassaigne examined
some wheat which was found in pulling down a house in
Paris, at the Quai de la Greve. It possessed a black colour,,
as if it had been converted into charcoal. It contained
neither starch nor gluten, but much ulmine or ulmic acid*.
The appearance of the grain led this chemist to believe that
it had been partially converted into coal, in a manner similar
to that in which trees and smaller vegetables have been
changed into coal, jet, and peat. Wheat found at Royat,,
near Clermont, (Auvergne) in the mountain called the
Granaries of Caesar, M. Lassaigne ascertained had under-
gone a similar change.

The precise researches of Raspail enable us to com-
prehend in some measure the cause of this stability in the
nature of starch. According to him, starch consists of
grains which vary in form and dimensions, the diameters
not exceeding, in maturity, '00393 inch; but before they
have attained their full size, being exceedingly more
minute. Those of the Hordium vulgare are about *009&
inch in diameter. In each grain, when viewed under

448 Dr. R. D. Thomson [June

the microscope, the rays of light are strongly deviated at
their entry and departure, so that only those reach the
eye which pass through the interior of the globule, and
hence, they appear as black balls with a white nucleus.
They consist of vesicles, filled with a gummy matter, which
hardens in contact with air. In water of the temperature
122° the bladder is expanded, probably by the increase in
volume of the gum. In boiling water it is ruptured and
precipitated, while the gum (the dextrine of Biot) dissolves
in the water. Iodine colours the grains, not by combining
with them, but by merely attaching itself to the exterior of
the visicles. The form of the grain is not altered ; for, if
inorganic salts capable of combining with the iodine, and
forming hydriodates, are mixed with the starch, the colour
disappears, and the starch remains colourless. #

The nature of the diatase which Payen and Persoz have
found in starch, Raspail explains in this way : In the act of
germination the grains of which starch consists increase by
successive layers, beginning nearest the cotyledon, while at
the same time acetic acid is formed ; now this acid dissolves
gluten, and renders it equally soluble in water and alcohol.
If the flour of germinating barley be macerated for an hour
in pure water, the water will dissolve the gum, sugar, and
gluten combined with the acetic acid. When exposed to
heat a flocky precipitate will be produced by the disen-
gagement of a portion of the acetic acid by heat, or of its
saturation by some base, disengaged from the tissue by the
temperature. Alcohol will increase the quantity of the
precipitate. Raspail digested for a few minutes some wheat
flour in acetic acid, at first concentrated, and then diluted
with a hundred times its weight in water. It was filtered,
and the liquid poured into a solution of starch. A precipi-
tation of the tegumentary matter immediately ensued.

These facts are extremely important when considered in
connexion with the process of malting, because they exhibit
in a powerful manner the greatness of the change which is
produced by the slightest effort of Nature's operations, and
because they enable us to comprehend more readily the
variety of alterations which the elements of grain undergo
in the same process.

* Nouveau Systeme de Chimie organique fond6 sur dea methodes nouvelles
d'observation par F. V. Raspail, 8vo. 1833, p. 8, 562.

1835.] on Malt, 449

The process of malting consists essentially, 1st,, in pro-
ducing a change in the constituents of grain by inducing
germination ; and 2nd. in stopping the vegetation when it
has been carried to a certain extent, by exposure to heat.
( To be continued.)

Article VII.

Analysis of Wolfram. By Mr. Thomas Richardson.

V<

In 1781 Scheele discovered a peculiar substance in a heavy
white mineral found in Sweden, to which he gave the name
of Tungstic acid, the base being called Tungsten from its
weight. Shortly after this Messrs. D'Elhuyart obtained
the same acid in a mineral called by the Germans wolfram,
which had been analyzed in 1761 by Lehmann, who con-
sidered it to be a compound of iron and tin. Weigleb and
Klaproth also analyzed this mineral, but nothing can with
any confidence be drawn from their results, both of them
having a deficiency of upwards of 21 per cent. Vauquelin
repeated the experiments of the Elhuyarts in 1706*, and
obtained the following :

Tungstic acid ...... 67*00

Protoxide of manganese . . 6 25
Protoxide of iron .... 18*00

Silica . ... . . . . . 1-50

92-75
Part of the iron Vauquelin supposes to be in the state of
peroxide. But even if this supposition were adopted there
would still be too great a deficiency to warrant us in
drawing any conclusion from the analysis. Berzelius
published a set of experiments upon tungsten in 1815, and
states the composition of this mineral to be, according to
his analysis :

Tungstic acid ..... 74*666
Protoxide of manganese . . 5*640
Protoxide of iron .... 17*954
Silica 2*100

100000

VOL. I. -i G

450 Mr. Thomas Richardson s [June

The quantity of tungstic acid was determined from the
loss, which prevents us from placing so much confidence in
it as we could otherwise have done, from the known dexte-
rity and precision of the analyst.

This mineral occurs generally along with tinstone, in
veins and beds ; it is met with also traversing greywacke,
with ores of lead, &c. It is found in almost all the Saxon
and Bohemian tin mines, as also in several places in
Cornwall.

It is thus found in France : In Siberia it occurs accom-
panying the emerald, and also in the United States of
North America.

It occurs massive, and often crystallized. The primary
form being a right oblique angled prism. The specimen
subjected to analysis was from Zinnwald, in Bohemia, and
seemed perfectly pure.

It possessed the following characters : —

Foliated; not very brittle; fracture uneven; streak,
reddish brown ; colour, blueish black ; lustre, approaching
metallic; opaque; hardness, 5*0 to 5*5; sp. gr. 7*017.

Before the blowpipe, decrepitates when heated alone,
but may be melted in a high temperature into a globule,
possessing the metallic lustre.

With soda, on platinum wire, it fuses into an opaque green
coloured bead in the oxydizing flame, which changes to
pink in the reducing flame : with borax fuses easily into a
transparent red coloured bead in the oxydizing flame, which
becomes pale yellow in the reducing flame. With salt of
phosphorus fuses readily into a transparent yellow coloured
bead in the oxydizing flame, which becomes red in the
reducing flame. On adding a small piece of tin to this red
coloured bead and continuing the flame for a short time the
colour changed to green.

It was analyzed in the following way : —

A. 20. grs. of the mineral, in fine powder, were kept
fused with 60 grs. of carbonate of soda (anhydrous) for half
an hour. The whole, upon cooling, was digested in water
for 48 hours. The insoluble portion which remained be-
hind was separated by a filter, and well washed with distilled
water. The solution which came through the filter, together
with the washings, being evaporated to a convenient bulk,

1835. j Analysis of Wolfram. 451

pure nitric acid was added , and the tungstic acid precipi-
tated of a beautiful yellow colour. After being well washed
with distilled water, acidulated with nitric acid, dried and
ignited, it weighed 14-39 grs., or 71*95 per cent.

B. The undissolved portion which remained on the filter
in (A.) was dissolved off by muriatic acid, and the solution
neutralized as exactly as possible with carbonate of ammonia.
The whole was now boiled with benzoate of ammonia
in a flask on the sand-bath, and the benzoate of iron which
it precipitated was separated by a filter. After being clean
washed, dried and ignited, the peroxide of iron which
remained weighed 2*58 grs. = 2*362 grs. protoxide of iron.

C. The solution and washings from (B.) being evaporated
to dryness, the whole was exposed to a red heat, to get rid
of the ammoniacal salts. What remained was dissolved in
water, and boiled with carbonate of soda. The manganese
which precipitated was separated by a filter, and after being
well washed, dried, and ignited, weighed 3*37 grs. red
oxide = 3*137 protoxide of manganese.

Hence, we have for the composition as follows : —

Tungstic acid 14*390 or 71*950

Protoxide of iron 2*362 „ 11*810

Protoxide of manganese . . 3*137 ,, 15*685

19*889 99*445
The difference between this and the preceding analysis of
Berzelius induced me to make another, and the result of
the second, executed in the same way, gave as follows : —

Tungstic acid 73*60

Protoxide of iron 11*20

Protoxide of manganese . . 15*75

100*55
Agreeing* with the first very nearly except in the quantity
of tungstic acid.

If we adopt Dr. Thomson's atomic weight of tungstic
acid, as given in the last Edition of his System of Chemistry,
and calculate, we obtain the following : —

atoms.

Tungstic acid 4.74 or 1*90

Protoxide of iron .... 2*49 „ 1*00
Protoxide of manganese . . 3*50 „ 1*40
2g2

452 Mr. Allan on the Cure of [June

Which approaches very nearly the following formula :

/« fn. + \\ mn. Tn.
But, if we deduce the atomic weight of Tungstic acid
from the last analysis, we have,

26*95 (the whole bases) : 4*5 (an atom of bases)'.'.
73*60 (the whole acid) : 12*28 (an atom of acid)
Approaching 12*25 as nearly as can be expected from the
inaccuracies incidental upon experiments. Employing 12*25
then, as the atom of tungstic acid, and calculating as before,
we get atoms.

Tungstic acid .... 6*00 or 2*41 nearly 2|
Protoxide of iron . . 2*49 „ 1*00 „ 1
Protoxide of manganese 3*50 ,, 1*40 ,, 1J
represented by the formula, /Tn. + 1| mn. Tn.

The difference between this and former analyses would
lead to the opinion that they were different species, since
both that of Berzelius and the present one agree exceedingly
well, with the atomic proportions deduced from the formulae
by which they are represented.

Great doubt still hangs about the atomic weight of
tungstic acid, and further experiments are required to
elucidate the subject.

Article VIII.

Erysipelas of the Extremities Successfully Treated by
Mechanical Pressure. By James Allan, Esq. Surgeon.

Dear Sir,

Should you deem the following cases illustra-
tive of a new and effectual method of treating Erysipelas of
the extremities worthy of a place in your valuable Journal,
you will oblige me by inserting them,

Dear Sir, yours truly,
10, Cannon Street, &th March 1835. James Allan.

To Dr. R. B. Thomson.

Case 1st., April 5, 1823. — Mrs. H. aged 40, of a sanguine
temperament and plethoric habit, complains of consider-

1835.] Erysipelas by Pressure. 453

able pain and heat affecting the whole of the back of the
right hand, extending about three inches above the wrist,
which is much swelled and reddened, pits on pressure, and
presents every appearance of phlegmonous erysipelas. Be-
came affected with a rigor and headache yesterday forenoon,
shortly after which the back of the hand became painful
and swollen. Pulse 100 firm ; tongue white ; bowels con-
fined ; appetite bad ; skin dry.

The hand, wrist, and forearm, the two first particularly,
were tightly bandaged and supported in a sling. She was
directed to take Magnes . sulph. half an ounce, with the same
quantity of Infus. sennce every four hours, till the bowels
were freely acted on, and requested not to remove the ban-
dage till I should see her again.

Ten hours after. Has scarcely felt any pain these last
eight hours ; bandage removed ; swelling and redness nearly
gone; bowels have acted freely from two doses of the
mixture. Bandage applied as before, but rather tighter,
and the arm supported in a sling; the mixture to be
discontinued.

— 6th. Has passed a comfortable night, having felt
only slight pain occasionally. Redness has entirely disap-
peared ; swelling scarcely perceptible ; pulse 80 ; tongue
white and moist ; skin moist. Bandage re-applied, and a
mixture similar to that ordered before to be taken every
four hours till the bowels become relaxed.

— 1th. Pain and swelling entirely gone ; experiences a
slight degree of weakness and stiffness in the hand, the
back part of which and the wrist are in some places of a
livid, in others of a yellow colour. The bandage to be
continued a few days longer.

— 9th. Feels quite well ; desquamation of cuticle going
on over the back of the hand. I saw her two days after,
when the hand was quite well.

Case 2nd. Nov. 16, 1832.— Mr. H. aged 46, of a melan-
cholic temperament and spare habit, was seized with a
rigor four days ago, which lasted nearly two hours. Com-
plains now of headach, thirst, pain and swelling of the right
foot and ancle, which are in a high state of inflammation,
and on which there are several vesications; redness extends

454 Mr. Allan on the Cure of [June

all over the foot and ancle, and about five inches up the
leg. Pulse 118, firm and small; tongue brown and dry;
skin hot and dry ; bowels confined ; has passed three very
restless nights, and is confined to bed. Ft. V. S. adoz. xv.
Ung. Cetacei, spread on lint, was applied over the vesica-
tions, and the foot, ancle and leg firmly bandaged. He
was directed to take Hydrary. submur gr. iii. and Pulv.
antimon. gr.iv., and six hours after Maynes. sulph. oz. i.

— 17 th. Mane. Has passed a comfortable night, during
the greater part of which he has slept. Since two hours
after the application of the bandage he has felt scarcely
any pain or burning sensation in the foot. Bowels have
not yet acted, the salts having been taken only an hour ago.
Pulse 86, weak ; tongue and skin becoming moist ; redness,
except on three or four small places, gone ; swelling very
much diminished, and very unequally diffused, owing to the
application of the bandage. A little discharge from some
of the vesications, the others dry. Uny. Cetacei to be dis-
continued ; vesications covered with oxyd. zlnci, and the
foot, leg, and ancle firmly bandaged as before, a piece of
lint being interposed between the skin and bandage.

Vespere. Felt a considerable degree of pain, which con-
tinued nearly an hour after the application of the bandage,
since which the parts have felt quite easy. Bowels have
acted freely. Bandage removed ; redness entirely gone ;
swelling scarcely perceptible ; no discharge from the vesi-
cations ; feels comfortable in every respect. Bandage to be
applied as before.

— ISth. Has felt no pain since yesterday. Pulse 76
natural ; tongue moist ; appetite good ; bandage removed ;
redness and swelling entirely gone ; desquamation of cuticle
going on ; considerable discolouration of a yellow and livid
hue on several parts of the foot ; a dose of salts and senna
to be taken.

— 19^. Is walking about and feels as well as usual,
excepting a slight weakness of the foot and ancle. Ban-
dage to be continued.

— 2\st. Feels quite well.

Case 3c?., Dec. 19, 1833. — Mrs. R. aged 54, of a sanguine
temperament and rather spare habit ; complains of pain

1835.] Erysipelas by Pressure. 455

and a sensation of burning in the left foot and leg, extending
from the toes to nearly the knee, accompanied with violent
headache, debility, and restlessness. Disease commenced
with several rigors two days ago. Pulse 122, small and
firm ; tongue dry ; skin hot and dry ; bowels confined ; the
foot, ancle and leg are very red, much swelled, and pit on
pressure ; three small vesications on the instep. 16 oz. of
blood were taken from the arm, a bandage tightly applied
from the toes to the knee, and a saline aperient given.

— 20th. Feels greatly better ; pain and swelling nearly
gone ; pulse 90 ; bowels open ; tongue still dry ; heat of
skin much diminished ; bandage again applied and aperient
to be repeated.

— 21st. Is nearly well, a very slight degree of swelling
continuing ; pain and redness gone.

— 23c?. Feels quite well ; no redness, pain, or swelling ;
bandage to be. continued.

The subject of this case has been for some years occasion-
ally affected with oedema, arising from disease of the heart.
I saw her about a month ago, when she informed me that
she had experienced no return of erysipelas of the leg, and
that her health had been considerably improved since that
attack.

I might have added a considerable number of analogous
cases, but I consider it superfluous, as all of them have
been precisely similar in their results, having treated every
case that has come under my care during the last twelve
years on the same principle, with uniform success.

It may not be amiss to state, however, that I was led to
employ bandages for the cure of Erysipelas in consequence
of observing the effect produced by the pressure of my
hand continued a few minutes on an erysipelitic surface.

In the case I allude to, I saw the disease after several
days standing. Leeches had been repeatedly applied and
the part kept cold with saturnine lotion ; notwithstanding,
the disease extended, the back of the hand became enor-
mously swelled, and began to present a sloughing appear-
ance. The acute stage had evidently passed. I applied my
hand with considerable force, and on its removal a few
minutes after, the swelling of the part covered with my

456 F. Rudberg on the Mean Temperature of [June

hand had greatly diminished. I immediately applied a
bandage tightly, and on its removal about eight hours after
I found the parts nearly well.

In regard to the modus operandi of the bandage, it ap-
pears to me that inflammation consists in arterial capillary
engorgement, which, when existing to a great extent, pro-
duces considerable obstruction to the circulation ; that the
bandage mechanically diminishes the size of these capillaries
and enables them quickly to regain their former size and
contractility.

Article IX,

On the Mean Temperature of the Ground at Various Depths.
By F. Rudberg .#

At the end of December 1832, three thermometers, by my
suggestion, and at the expense of the Academy of Sciences
at Stockholm, were put in the ground at that place. They
were filled with mercury, and were compared while in the
vertical position with an accurate thermometer, so that the
influence of the mercurial column was provided against.
The thermometers were placed in glass tubes, which were
shut at the bottom by perforated stoppers, and filled with
fine sand. The depths at which the balls of the three ther-
mometers were placed, were one, two, and three feet respec-
tively. The place where they were buried lies in the middle
of that considerable plain on which the astronomical and
now also the magnetical observatories are situated.

The observations began in December of the above year ;
but during the first six months they were made only once
a day. After that, however, the thermometers were ob-
served three times in the day, at 6 a.m. and at 2 and 9 p.m.
As the natural equilibrium of temperature would of course
be disturbed by digging up the earth, and a considerable
time would be requisite to allow this to return to its usual
state I shall here omit the observations of the first half
year, and state only those from the 1st. of July 1833, to the

* From Pogg. Ann. xxxiii. 251.

1835.]

the Ground at Various Depths.

457

1st. of July 1834. The monthly means of these are the
following : —

1833. July . .
August .
September
October .
November
December

1834. January .
February .
March .
April . .
May . .
June . .

TEMPERATURE AT THE

DEPTH OF

OVE FOOT.

TWO FEET.

THREE FEET.

60-548 f

59-000

56-966

55-616

55-456

55-184

53-924

53-610

53-474

48-146

48-344

49-262

39-002

40-316

42-206

33-458

35-186

37-004

29-282

31-244

32-720

31-316

31-964

32-432

32-640

33-134

33-440

38-048

37-436

36-932

48-020

46-562

45-104

56-570

54-500

52-312

If we take the mean of the result of each thermometer,
then will the mean annual temperature of the ground at
Stockholm be,

At the depth of 1 foot 43*880

2 feet 43-898

3 feet 43-906
Whence, it follows that the mean temperature of the ground,
at least to the depth of three feet, is independent of the
depth ; and in all probability this proposition will be correct
for all depths, till the point where all variation of tempera-
ture ceases.

The table shews, besides, that temperature at the end of
September and the end of March, or at the time of the
vernal and autumnal equinox, is the same at all these
depths.

Although more observations may be required to settle
these two propositions, I have, nevertheless, thought it
proper to draw the attention of meteorologists to them that
they may try their accuracy in other places.

This mean temperature of the earth is greater than the
mean temperature of the air at Stockholm, which is only
42-24 F.

458 Scientific Intelligence. [June

Article X.

SCIENTIFIC INTELLIGENCE.

I.' — Ashmolean Society of Oxford.

The first memoir printed by this Society is entitled, " On the
Achromatism of the Eye. By the Rev. Baden Powell, A.M." &c.
It is well known that when rays of light are inflected by a lens
they undergo a deviation, by which they are prevented from con-
centrating in the same point or focus. This aberration gives origin
to the production of colour at the foci of lenses, and constituted a
great imperfection in refracting telescopes until the discovery was
made, that a compensation for the deviation of the rays of light might
be effected by employing compound lenses. Those telescopes in
which this improvement was introduced were termed achromatic.
Now, as there appears no compensation in the eye for this aberration,
it is natural to inquire into the reason of our seeing objects without
prismatic colour. Such is the question which Professor Powell
undertakes to investigate in the present paper. He presents us first
with the opinions of various philosophers in reference to the subject,
and then supplies us with inferences drawn from his own experi-
ments. D'Alembert admitted the want of achromatism in the eye,
but considered the aberration very small. Euler held an opposite
opinion, and Dr. Maskelyne refuted the arguments of Euler. Dr.
Wells has observed that the eye has no principle of achromatism, and
Sir David Brewster says that " no provision is made in the human
eye for the correction of colour, because the deviation of the differently
coloured rays is too small to produce indistinctness of vision." Mr.
Coddington states that the eye, when employed in its natural and
proper manner, is achromatic. The fact is, that we see objects with-
out the slightest degree of prismatic colour or indistinctness. The
question then is, how can this be reconciled with theoretical consi-
derations ? Mr. Powell, by ingenious calculations, has inferred that
in such a combination as the eye, exact achromatism is perfectly
possible in theory, and that the principle of its achromatism, although
not effective in obtique excentrical rays, may be in general achromatic
for direct rays. He gives the results of a series of experiments,
in which he has ls endeavoured to ascertain directly the actual
prismatic dispersions of the crystalline and vitreous humours, by
measuring micrometically the separation of the different parts of the
spectrum of a line of light produced by looking through a prism
formed of each medium, from the eye of an ox, between inclined
glass plates." From which he concludes " that the media of the eye
have as nearly as possible those dispersive powers and relations of
indices for the different rays, which theory requires for producing
achromatism by means of a single lens, when the focus is formed in
a dense medium."

February 13, 1835 — Mr. Twiss of University college exhibited
some specimens of the papyrus from Syracuse, both in its natural
and manufactured state. He read some observations upon it, describ-

1835. Scientific Intelligence. #M

ing the locality where the plant grows on the banks of a small stream
issuing from the fountain of Cyane, near Syracuse. It is now
manufactured merely as a curiosity.

Some discussion took place on the supposed identity of the papyrus
with the lotus.

Mr. Twiss exhibited to the Society a series, almost complete, of
the silver and bronze coins of the Roman republic, and read a disser-
tation upon them.

In this paper the author commences with observing the gradual
decline in weight of the As from the time of the kings through the
successive ages of the republic. The value of the copper is compared
with that of the silver coinage ; and the author is of opinion that the
rise in the value of copper is chiefly accounted for from the diminu-
tion of the supply, both from the exhaustion of the mines, and the
interruption of the commerce with the Carthaginians, as well as from
the circumstance of copper being re-exported to Sicily ; these causes
acting more powerfully about the time of the second Punic war, when
the As was diminished to an ounce, from its original weight of ten or
twelve. The last diminution, to half an ounce, took place in the
time of Sylla. Silver was introduced into the currency after the
conquest of Campania and Lower Italy. Observations are made on
the silver coinage, and particularly on the devices appearing on
them : and the author then gives a general sketch of the financial
arrangements, and state of the currency, at successive periods of the
Roman history.

February 2*Jth. — A paper was read by the Rev. E. T. Bigge of
Merton College on the natural history of the wasp.

The object of this paper was to correct the mistakes into which
several writers have fallen, and to state the results of the author's
own observations on two species, the Vespa Vulgaris and Vespa
Britannica.

The former is common in all parts of the kingdom ; the latter,
though occasionally met with in the southern counties of England,
is abundant in the northern districts, and in Scotland, as well as in
the northern parts of Europe. The V Vulgaris of Linneus is the
V Britannica, the French having called that species vulgaris, which
was most common, and which formed its nest in the ground.
The V Vulgaris of the present entomologists is the V Gallica of
Linneus.

Leach gave the name Vespa Britannica to the tree wasp. The
points of difference between the two species are as follows: —

1. The tree wasp (V Britannica) has a reddish-brown spot near
the point of insertion of the wings, which is seldom visible in dried
specimens.

2. In the males and neuters the base of the antennae is yellow on
the outer side, instead of being entirely black, as on the ground wasp,
but the females often present exceptions to this distinction.

3. The tree wasp has two yellow spots on the back part of the
corslet, while the ground wasp has from four to six.

4. The spots on the abdomen of the tree wasp are not so much
detached from the black bands as in the other species, and less so in

46O Scientific Intelligence, [Juke

the males than the females. Linneus drew a distinction between
the hornets (V Crabro) and the true wasps, founded on these marks,
which cannot be considered as decisive, because they vary in different
individuals.

5. The tree wasp has more black upon the body generally than the
other species.

6. The tree wasp is rather larger. 7« The organs of generation
in the males of the two species vary considerably. 8. The abdomen
in each species contains the same number of rings, viz. six in the
females and neuters, and seven in the males.

Mr. Bigge states some interesting facts in illustration of the natural
history of both species. Societies of wasps, as of bees, consist of three
different classes of inhabitants, males, females, and neuters. The
females, which are much larger than the others, are the large breed-
ing wasps which appear in the spring. The neuters, or imperfectly
developed females, are the common wasps which infest our houses and
gardens, and form the majority of the colony. The males, about the
size of the neuters, have longer antennae, a more slender form, and
are destitute of a sting. The females, which alone survive the winter,
early in the spring, having fixed on a suitable place for a nest, form a
few cells, in which they lay the eggs of neuters only. Each nest is
the work of a single female. The nests are often suspended from the
beam of a shed, from the eaves of a house, from the branch of a young
tree, or in a thorn hedge.

Mr.Bigge has observed them in the Scotch fir, elm, and beech,
very frequently in larch trees, and still more so in goosberry bushes,
but never in the silver fir, as stated by Mr. Rennie.*

The nest consists of from ten to sixteen layers of a paper like
substance, procured principally from fir wood, and disposed one over
the other in such a manner that each sheet barely touches the next.
This structure enables it to resist the heaviest rains. In its earliest
state it does not exceed an inch in diameter, and contains five or six
cells only.

It is formed of two semicircular layers of the paper, the upper one
projecting a little over the other, so as to shoot off the rain, a hole
being left at the bottom large enough to admit the female wasp. As
soon as the first workers quit their cells they begin the task of en-
larging the nest, and of adding fresh layers of cells, in which the
female immediately deposits more eggs. Mr. Bigge states that the
nest is enlarged from one inch to twelve in diameter, and considers
that Leach is in error when he affirms that wasps build two nests
in the year.

Is not the loose structure of the external covering intended to
facilitate its expansion ?

The egg is hatched in eight days, and then assumes the form of a
grub. It is then fed by the female for thirteen or fourteen days,
when the grub covers the month of its cell with a silky substance.
It remains in this state for nine days, and then eats its way through

* I have frequently observed nests situated on wild rose bushes (Rosa tomen-
tosa and canina,) in Scotland. The choice of these slirubs by the wasps is proba-
bly to be ascribed to the facilities which they afford for obtaining food. — Eon.

1835.] Scientific Intelligence. 461

the covering, and joins the rest in the labours of the nest. As soon
as the neuters are hatched the care of feeding the larvae devolves
upon them. The males appear to employ themselves in cleaning and
preparing the cells for successive broods.

Mr. Bigge has never found, in any single instance, a male larva
in the cells appropriated to females. He has repeatedly found male
grubs in the upper layers, which are devoted to neuters, but never
the contrary. The beautiful arrangement by which the layers in
the nest are attached to each other so as to allow room for the wasps
to walk between them deserves attention. In the ground nests the
supports or braces are round, like small columns, and dispersed at
irregular distances. The upper end is spread along' the edges of
three cells so as to divide the pressure, and yet allow room for the
grubs to work their way out when they are come to maturity. In
the tree nest, instead of pillar like braces, thin slips of the paper of
which the whole nest is composed but made stiffer for this purpose,
are continued along the edges of a number of cells, so as not to
interfere with the inmates, and are finally fixed to the layer below.

The author has never seen a nest of either species, in which he
did not observe after 9 o'clock in the summer months, a sentinel
watching the entrance to the hive. He has sometimes thought, that
he could discern a second sentinel, behind the first one. A lantern
held near the sentinel does not disturb him, but on touching the
ground near him, he instantly disappears for a few seconds, and the
inhabitants sally out immediately. Several wasps pass the night in
summer on the outside of the tree nest, but the sentinel is notwith-
standing always at his post.

The ground nest has two apertures, one for entry and the other
for exit. The tree nest has usually only one, but in large colonies
there are two, at each of which a sentinel is stationed. It is curious,
that if we stop up a wasp's nest, the returning wasp will not sting
the aggressor, while those which escape from the inside will attack
him instantly. The grub of a species of volucella is found in the
nests of wasps. An ichneumon as large as the wasp itself, with
a black head, yellow abdomen with a dark streak down the back,
black legs and under wings, and dusky upper wings has been observed
by Mr. Denison, and another (Anomalon Vesparum) by Mr. Wood.
Mr. Twiss mentioned a peculiar kind of wasp's nest which he had
observed on the Cactus in Sicily. The author suggested the query,
whether it was not the Epipone Fidulans, sometimes found also in
England.

Dr. Kidd read a paper on a species of manna produced in the neigh-
bourhood of Mount Sinai.

It is a gum which exudes from a species of tamarisk, through
minute punctures in the bark made by insects. It drops upon the
ground in a liquid state, but congeals by the cold of the night. It
is eaten by the natives, and has a sweet taste.

Though denominated by Niebuhr, "manna Israelitarum," the
author argues that it must not be confounded with the manna m en-
tioned in Scripture, since the quantity produced at the present day
would be utterly inadequate to the supply of so numerous an assembly.

46'2 Scientific Intelligence. [Juuf.

The paper was illustrated by a large coloured drawing.
Mr. Plumptre stated, that a deposition of manna had been ob-
served by Mr. Gray, in the same part of Arabia, at a distance from
any trees, apparently condensed, or precipitated from the atmosphere,
and appearing deposited on objects like hoar frost.

March. I3lk. — An anonymous paper was read, entitled " Physical
elucidation of a passage in Horace."

It appears to the author of this paper, that notwithstanding all
the difficulties which have been felt, and the learned ingenuity which
has been exercised upon the passage, (Ode 10. bk. iii.)

" Puru numine Jupiter,"
the epithet " Turo" may be allowed to stand as the true reading,
being entirely conformable to the known belief of the ancients;
according to which the coldness of the night was inseparably asso-
ciated with the clearness of the sky. This impression, though
sometimes mixed up with fanciful conceits as to the effect of the
moon's rays, &c. was very probably grounded on extensive observa-
tion, though they might be little aware of the cause to which the
effect was to be referred. This is now well understood to be the
radiation of heat from the earth's surface ; which goes on more freely,
or in other words, the earth cools more rapidly, at night (caeteris
paribus) under a clear sky, than under a screen of clouds, which
intercepts the radiant heat.

An anonymous paper was read " on a difficulty in the history of
the publication of Newton's Principia." -

In Birch's History of the Royal Society, (vol. iv. p. 486.) the
following passage is given, as extracted from the journal books of
the Society :

u Minute of the Council. 1686, June 2.

" Ordered, that Mr. Newton's book be printed, and that Mr.
Halley shall undertake the business of looking after it, and printing
it at his own charge, which he engaged to do."

But it also appears, that at a meeting of the Council on the 19th
of May (1686) it was resolved "that the MSS. should be printed
at the Society's expense, and that Dr. Halley should superintend
it while going through the press."

Yet this seems to be contradicted by the language of the first
extract ; and the difficulty has been remarked by the learned author
of the " History of Hadley's Quadrant," which has appeared in
several recent numbers of the Nautical Magazine. He expressly
observes in a note, u It is hardly possible to conceive, that the R.
Society, after undertaking to publish the work, could, either from
deficiency of funds, or from any other cause, have thrown the burden
of it upon Halley. But the minute is unintelligible, if it does not
imply, that he either engaged for some positive expense, or gave
up some serious remuneration, to which he would have been justly
entitled in the prosecution of the publication."

The author, however, wishes to submit, whether the whole diffi-
culty may not be cleared up at once, by the simple consideration of
the punctuation of the first extract ; viz. if we read it thus :

" That Mr. Halley shall undertake the business of looking after

1835.] Scientific Intelligence. 463

it and printing it, at his own charge :" that is to say, shall, at his

own charge of whatever trouble or minor expense may be incidental
to it, undertake the superintendence of the printing.

Professor Powell communicated a paper on the present state of
the question respecting the theory of the dispersion of light.

The grand optical discovery of Newton referred to the unequal
refrangibility of those primary elements of light, which were desig-
nated generally as the red, blue, &c. rays. Each of such species
of light was observed to have its refrangibility different, and increas-
ing from the red to the blue end of the scale. Newton's successors
soon found that the refrangibilities were not only different among
themselves for the parts of the spectrum formed by a prism of the
same substance, but followed no perceptible proportion, when com-
pared from one medium to another. The only attempt to estimate
them numerically, consisted in finding the mean refractive index for
the substance, and inferring the indices of extreme rays from the
amount of separation or dispersion observed. Thus up to a late
period, the indices were only determined for the red, blue, and mean
rays vaguely and without exact definition ; as it depended only on
the judgment of the eye to say how far the red (e. g.) should be con-
sidered to extend, and where the yellow should begin ; and what
point of the red or yellow, &c. should be taken for the point of
measurement. Among the refractions observed thus vaguely for
different media, no apparent relation or connexion could be traced :
and no theory, whether of emission or of undulation, appeared to
afford any explanation of the phenomena. Indeed, all comparison
between the rival theories on this point might have been spared,
since not even the law of the phenomena, nor even an exact know-
ledge'of the facts themselves, had been obtained. All theory \ was,
therefore, premature.

More recently the singular fact of finely-marked dark lines being
seen to cross all parts of the spectrum (discovered independently by
Dr. Wollaston and Mr. Fraunhofer) afforded the means of more
accurate measurements. They formed precise points, assuming dif-
ferent relative positions for the different media employed : and by
means of them, Mr. Fraunhofer determined with the most elaborate
precision, the refractive indices for seven principal lines or definite
rays, in each of ten different transparent substances. Thus science
obtained the first important requisite, without which no satisfactory
investigation of causes can proceed, exact numerical data. But the
more exact the data, still only the more palpable was the seeming
absence of any law.

Further, Newton had determined the lengths of those intervals or
periods (which he called Jits, but the undulationists waves) which,
by whatever name they may be called, have a real existence in the
nature of light. These are different for the different rays. Newton
determined them only for the red, blue, &c. rays in the same general
sense as before ; but Fraunhofer measured them accurately for the
seven definite rays above mentioned. Here then is another set of
numerical data : and the first obvious inquiry towards investigating
a law would be, Can any relation be traced between these two sets
of data for different rays and different media ?

464 Scientific Intelligence. [Juki:

This question must be examined before we can pretend to enter
on any discussion of theories. And the present state of the inquiry
is precisely that in which the answer to this question forms the sole
important and legitimate object of attention. An attempt to answer
it, has formed the subject of the author's labours for some time past,
by a comparison grounded on a formula deduced from M. Cauchy's
researches ; which appears to give a very close accordance. The re-
sults will shortly be published.

II. — Royal Institution.

Comparison of the two theories of Electricitu. 3rd April,
Dr. Ritchie stated, that at present there are two theories which have
been proposed for the explanation of electrical phenomena. One
which is the simplest theory, supposes that they depend upon the
existence of a fluid universally diffused through matter and space,
the particles of which repel each other inversely as the square of the
distance. If we abstract a portion of this fluid from a body, the
latter becomes negatively electric : while if we add a portion, we
produce the phenomena exhibited by positive electricity.

Another theory considers electricity to be a compound substance,
consisting of two elements, positive and negative electricity. None
of the phenomena are observed until this fluid is decomposed, and
then a portion of it goes to the attracted body.

Upon this supposition we can best explain why divergence of the
gold leaves in an electrometer should take place in vacuo. Perhaps,
the fluid may be the ether, to which the phenomena of light seem
attributable. But unless it be a compound fluid, it is not possible to
explain the fact, that when a vessel, in which there is a small aper-
ture at the bottom is filled with water, when it is attached to either
conductor of the machine, there is formed a regular stream through
the aperture.

Now, if there were two fluids the same appearances should not be
exhibited at both conductors. When a bit of wax is attached to
either conductor, heated, and then the machine set in motion, the
wax is thrown upon white paper held below it, in the form of a
beautiful thin film. It is difficult to explain the fact, that when we
place a card between two fine points, and discharge an electric jar
through them, the card will be pierced opposite to the negative point.
The reason perhaps is, that the paper is a better conductor of one of
the elements of the fluid than of the other. The card on each side
presents the same appearance, which leads to the conclusion, that a
fluid has passed through from both sides.

According to the theory of Franklin, the actual particles of matter
repel each other, which is contrary to the law of gravitation.

By considering electricity as a compound body we can explain also
the electrophorus.

In order to confirm the idea of the existence of two elements, we
can by a beautiful experiment separate one element from the other.

If we place two conductors united by their contact with fine points,
at a considerable distance from the conductor attached to the ma-
chine, charge the machine, and then suddenly remove one of the
separate conductors to the electrometer, we obtain a divergence in

1835.] Scientific Intelligence. 465

the gold leaves of the latter. To determine the nature of the elec-
tricity which has thus been separated is easily accomplished, by means
of a glass rod excited, or a substance covered with a resinous coating.

Dr. Ritchie suggested that by a modification of the galvanometer,
base coin may be readily detected. A bad sixpence which he sub-
mitted to examination produced a very rapid deviation in the needle.
He is of opinion that jtfW °f copper mixed with silver might be
by this method appreciated.

Dr. Ritchie endeavoured to afford an explanation of Dr. Faraday's
experiment, in which, the spark was elicited in a long wire, by the
consideration, that one particle of light does not communicate light.
Now, in the long wire the quantity of electricity was smaller than in
the short wire, but took a longer time to arrange itself.

The able lecturer exhibited an electro-magnetic machine, in
which he had devised some improvements, by which combustion and
decomposition can be as readily effected and more conveniently than
with a voltaic pile. This affords an excellent instrument for class
room experiments.

Dr. Lardner on Halley's Comet. 10th April. Up to the
time of Kepler, philosophers were in the habit of forming systems
and cutting down nature to suit their own theories. He produced,
however, a revolution in the science of astronomy, and proceeded by
the sure process of induction, to study the nature of the planets. He
selected Mars, because it is nearer us than any of the other planets.
He found it impossible that this planet could revolve in a circle of
which the sun is the centre, an opinion which had been long enter-
tained. Still he was unwilling to abandon the idea, that its orbit
was a circle ; and he endeavoured to ascertain, if it might not
revolve in a circle with the sun out of the centre. But he could
not reconcile its motion even with this supposition. He then banished
the idea that its orbit was a circle, and by a fortunate or instinctive
guess, concluded that it was an ellipse. Now, this is a very remark-
able circumstance, because it varies so very little from a circle, that
if it were delineated on paper, it would be impossible so say that it
was an ellipse, without very accurate measurement.

By analogy, he extended the conclusions to which he had come,
in regard to Mars, to all the planets. He further demonstrated,
that by the planets, equal areas are described in equal times. Newton
followed out this law, and shewed that the attracting force diminishes
with the square of the distance. He found by reversing this problem,
that the orbit must be a curve, of which an oval forms an instance.

The ellipticity of the orbits, it was shewn, however, does not
depend upon physical laws, but upon the will of the Creator, because
in proportion to the force with which they were launched into space,
they would follow the curve of an ellipse, of a parabola or hyperbola.

All the planets are collected in the zodiac, from what cause we
are not aware, and they all revolve in the same direction. Such are
the principal features in the motions of the planets. Now, with re-
gard to comets, we find that they differ as much as they possibly can

VOL. I. 2 H

466 Scientific Intelligence. [June

do consistently with the laws of nature. The orbits of some of them are
extremely elliptical, of others almost circular, so that they follow no
constant law. They have no preferable plane in which they move,
some moving at right angles, others not. In short, they are a kind
of physical vagabonds. Some of them move direct, or in the direc-
tion of the planets, others retrogade ; 68 move one way, 69 the
other. They possess no characters such as the planets possess, as the
satellites of Jupiter, the belts of Saturn, &c, by which we can iden-
tify them, for they are surrounded by a mass of vapour, and are
therefore, seen by us indistinctly ; sometimes their tails grow longer,
sometimes shorter. The comets can only be seen at the focus of their
orbits or at that point where they are not too far from the earth, and
not too near the sun. But as this position is the very point where
curves of an ellipse, parabola or hyperbola, correspond, we must have
recourse to some other method than a single observation, to determine
their orbit. This is done by their periodicity. If they return perio-
dically, we are sure that their orbit is an ellipse ; if it is a parabola
or hyperbola, they will shoot off into space and never appear again.
Now, it is easy to calculate the degree of ellipticity of the orbit,
because Newton has demonstrated in his Principia, that the squares
of the periodic times are to each other as the cubes of the distance of
the respective planets from the sun. Knowing, therefore, the pe-
riodic times, the ellipticity and size of the orbit can readily be deduced.
To this point, therefore, Newton brought the question — He said,
<( the orbit of comets is an ellipse, but I have not time to determine
the axis : I leave this to succeeding astronomers." Halley took it up
in 1 700, where Newton left off. Before his time, 425 comets had
appeared, but 24 only had been observed, the rest were only seen
From the observations which had been made upon these 24 comets,
he calculated their courses. He found the elements of one which
appeared in 1607, to agree with one he had observed in 1682, and
on examining other observations, he found, that the following table
could be formed in reference to one comet.

Years.

Periods.

1305

1380

75 years.

1456

76 „

1531

75 „

1607

76 „

1682

75 M

1759

77 »

1835

76 „

He ascribed the differences in the periodic times to the attraction
of Jupiter and Saturn. He guessed this as if by instinct, for he
really had not at the time the philosophic means of determining it.
In 1757, Lalande proposed to Clairaut, the calculation of Halley's
comet which was expected to return speedily. They were assisted
by a French lady, the wife of a chronometer maker. The calcula-
tion was enormous, because the ^orbit must be divided into degrees,
and each degree requires as great a calculation as the whole orbit.
They tell us, that they were employed from morning to night, not
excepting meal hours, incessantly for six months in this computation.

1835.] Scientific Intelligence. 467

Clairaut was so nervous that he hurried his calculation before the
Institute, although he had not completed it. He stated, that the
comet would reach its perihelion on the 4th of April, but that it
might be seen sooner.

Voltaire has said, that the philosophers did not go to bed in the
beginning of the year, so anxious were they to observe it. Notwith-
standing their anxiety, it was discovered on Christmas day, 1758, by
a farmer in the neighbourhood of Dresden ; and then by Messier in
the middle of January at Paris. It reached its perihelion on the
13th March. Now, although Clairaut was not quite correct as
to the day, the only wonder is, that he should have been so accurate,
for as he said, when a body traverses a space of 1500,000,000 of miles
beyond our sphere of observation, how do we know but that some
other planet may act upon it and influence its course. In 25 years
the planet Herschel was discovered, which it was proved, did actually
operate in producing the effect which Clairaut had surmised.

1st May. The comet of this year will appear in the end of
October or beginning of November. The cause of this uncertainty,
is our want of knowledge of the mass of the planet Herschel. Four
different davs have been fixed on by calculators. These are,
31st October, 4h. 46' 58-8

5th November, 7 >, 40 „
8th „ 4 „ 48 '„

10th „ 2 „ 30 „ A.M.

On the 7th of October, it will be near the head of the great bear,
and will be visible after sunset. On the 11th, it will be near the
tail of the same constellation. On the 10th, it will make its nearest
approach to the earth. It is probable, that it will be of less magni-
tude than it was in 1759, if we are to judge from its most recent
history ; but if we go back to the appearances which it presented at
its first periodic times, this conclusion is not warranted. Its history
has been traced back to 150 years before Christ. In 54, it was also
observed, and was so bright that the birth of Mithridates, who came
into the world in this year was ascribed to it. After this period it
must have returned five times without having been noticed. In 323
it is again recorded. In 399 it again appeared, when it was of great
magnitude. In 550 it is again recorded, and also in 930, and 1250.
In 1305 it possessed great splendour, and in 1456 its tail was of such
enormous extent that it occupied two thirds of the space comprized
between the horizon and zenith, or above 1,500,000,000 of miles.
In 1531 it had diminished in size. In 1607 it was still less, and
was discovered by Kepler when returning from a dinner party. The
tail was invisible. In 1759 it had the appearance of a fixed star sur-
rounded by some luminous matter. Hence, it is probable that this
year it will be smaller. But, at the same time, we cannot fail to
remark that it has increased and diminished without any regularity.

There are only two suppositions which present themselves to ac-
count for its non-appearance should that happen, viz. : 1. That a
planet may exist beyond Herschel which may exert its influence on
it and draw it out of its orbit, or 2. it may have met with another
comet during the interval which has elapsed since it last appeared,
which may have carried it off".

2 h 2

468 Scientific Intelligence. [June

There are only two other comets which have been observed to ap-
pear periodically. These are EnckcVs and Beile's comets ; but these
are of very small magnitude. Encke's has appeared two years sooner
than can be accounted for by the laws of gravitation. Beile's was
discovered in 1826, since which year it has only returned once, but
was accelerated one day beyond the results of calculation. These
are the two arguments for a resisting medium, and the existence of
an ethereal fluid.

In June 177°* Messier discovered a brilliant comet within the
orbit of Jupiter, and Lexell computed it. Previously it was thought
that comets moved in a parabola. He inferred, however, that it
moved in an ellipse, and that it would return every 5 \ years. It
did not return, however, as he had predicted. Laplace, however,
shewed in the 2nd chapter and 9th book of his Mecanique Celeste,
that in January 1767 it must have entered within the attraction of
Jupiter, and was acted upon by that planet so as to give it an ellipse
of 5f years for its orbit, that at the end of the first 54 years the sun
obscured it, and at the 11 years Jupiter crossed its orbit and entangled
it again. This was a splendid triumph of mind over sense, for La-
place first gives a general formula for calculating the retardation of
a comet with a given track, anterior and subsequent to its appearance,
and then merely takes the comet of 1770 as an example for the appli-
cation of the rule.

If the mass of this comet were equal to that of the earth, the at-
traction exerted would shorten the year 10,000 seconds; but it has
been found that the year is not diminished 2 seconds, and hence, it
must be inferior to the mass of the earth. This comet afterwards
went in directly among the satellites of Jupiter without disturbing
them in the slightest degree : from which circumstance we can
scarcely fail to conclude that it was lighter than light. Much dis-
cussion has taken place with regard to the nature of the constitution
of comets. Sir John Herschel observed a fixed star through the head
of a comet. It has been said that the direction of the tail is influ-
enced by the sun, but this is incorrect, because some comets have had
two tails, one pointing to the sun; and the other from it, while others
have had six tails all pointing in various directions, and vacillating,
so that comets may be said to wag their tails. Comets do not shew
phases like the moon, because they are not solid, but are more like
fleecy clouds when the sun shines upon them. M. Arago suggests
that the only method of determining whether they are essentially
luminous or not must be by the investigation of their phases, and the
comparative intensity of their light by means of photometers. It is
remarkable, that they grow larger as they recede from the sun. Sir
John Herschel has offered two explanations of this: 1. By consider-
ing them to consist of particles which have little cohesion, and which
move in a variety of orbits, and get closer as they approach the sun :
or 2., and this is the most ingenious attempt at the solution of the
difficulty ; that when cooled the particles condense as we observe in
steam issuing from a kettle, the portion nearest the source of heat
being invisible, while at some distance a cloud of vapour is observed.

Five or six hundred comets have been recorded, but of 1 37 only
have the tracks been observed.

These follow no regular angle of inclination ; neither are the planes

1835.] Scientific Intelligence. 469

of their perihelia nor their ascending nodes regular. The times of
their perihelia are also irregular. These are

January 14

February 10

March 8

April 10

May 9

June 11

July 10

August 8

September 15

October 11

November J8

December 13

137

The number of those whose course is direct is .

Retrogade

137

If we assume that there are 30 comets in the orbit of Mercury,
and no more, (but assuredly there are more ; these 30 have been ob-
served), then within the orbit of Herschel there will be above
3,000,000 of comets, or 7,000,000 within the solar system.

Note. — Olbers is of opinion that people in general will allow the
comet of this year to pass without notice, in consequence of the poor
supply of light. The following table of its course is taken from a
short paper by Arago, in the Annuaire for this year. By means of
it the track of the comet may be studied on the celestial globe, by
those who are not familiar with the geography of the heavens, and
their knowledge thus acquired may be applied to the real objects.
The comet will be found

near '( in the Bull
between the Twins and Auriga
in Auriga (the charioteer)
in Lynx
in the Great Bear

On the 20th

August, 1835

28

u

21st September

3rd October

6th

t<

Uth

tt

12th

<t

13th

a

15th

tt

19th

tt

1 6th November

26th

tt

in Bootes

in the Crown

between Hercules and the Serpent

in Ophiucus

near v of Ophiucus
in Scorpio near Antares
Mr. Wheatstonc on Speaking Machine*. Sth Mai/. — Mr.
Wheatstone gave an account of the different attempts which have
been made to invent speaking machines, from the time when the
oracular responses were delivered at Delphi, through the period
when a speaking head was exhibited by the Pope towards the end of
the 10th century, and others afterwards, by Roger Bacon and Alber-
tus Magnus, with the impositions which were practised upon the
credulous, to the present time, when the principle of a speaking
instrument has been developed by Mr. Willis. Van Helmont was

470 Scientific Intelligence. [June

one of the first persons who wrote upon the adaptation of the organs
of voice to the articulation of the letters. He considered that the
letters of the alphabet constituted the order in which articulate
sounds were naturally produced, by the structure of the tongue and
larynx ; that when one letter is uttered the tongue is in the proper
position for the pronunciation of the subsequent one. By attending
to the circumstance, that several different sounds are formed, merely
by raising or depressing the tongue slightly, as in the sounds Aw,
Ah, Ae, A, E, it was easy to produce them by means of a tube with
a reed and terminating in a bell. Mr. Willis also effected the same
object by using a long tube with a reed, adapted so as to be capable
of being lengthened or abbreviated at pleasure. He found, that in
the pronunciation of the vowels, i, e, a, o, u, it required to be shortest
with the first, and in uttering the subsequent letters to be gradually
lengthened. In this way, it was easy to measure the length neces-
sary for each note. When Ae was pronounced, the tube was 1 inch
long, Aw 3-8 inches, Ah 2-2 inches, A 06 inch, E 0-3 inch.

Mr. Wheatstone exhibited a copy of a speaking machine which
was invented in Germany, and afforded a specimen of its vocal powers.
The words, mamma, papa, mother, father, summer, were distinctly
pronounced. The instrument consisted of a pair of bellows, to which
a tube is adapted, terminating in a bell, the aperture of which is
regulated by the hand, so as to produce the articulate sounds.

III. — Metropolis Soft Spring Water Company.

A printed letter has been sent to the Editor, with this title, signed
" A Manufacturer," containing some observations which ought to be
generally known. The projectors of this company assume that the
London basin " contains a subterranean lake^ and an inexhaustible
supply of water." The writer informs us, that in two large wells and
two bore holes which have been made in his manufactory, at different
periods, between 1810 and the present time, '.' the supply of water
though at first abundant in each of them, has gradually and uniformly
diminished in all. The principal well, nearly a new one, obtains its
supply from the whole of the thickness of the quicksand ; for the
lower end of the bore pipe which terminates with a 10 inch opening,
is bored full of holes for the last 30 feet and rests upon the face of
the chalk." Notwithstanding, after affording an apparently inex-
haustible supply for some years, in the course of last summer (1834)
the water was repeatedly drawn down to the suction guard, which is
90 feet from the surface, and the working of the engine was often
stopped for the purpose of allowing the water to collect. He states,
that when one of the wells mentioned has been pumped for some
hours, the water in another well, at a distance of 3 miles, is consider-
ably lowered. And very properly observes, that as many of the
largest manufacturing establishments are dependant upon these
springs for their supply of water, they have a right to ask from what
source they are to expect compensation t

These facts, which we believe to refer more immediately to the
southern portion of the metropolis, are consistent with the experience
of the inhabitants of the northern part also, where for the last two
months, many of the wells have been dried up. The bill for the

J 835.] Scientific Intelligence. 471

incorporation of the company has been read a first time in the House
of Commons. But before it proceeds further, injustice to all parties,
it will be absolutely necessary that more information should be
collected.

IV. — Address to Meteorologists.

At the suggestion of Sir John F. Hersehel, (Athenaum, April)
the Scientific Society at the Cape of Good Hope has agreed to
undertake to make horary observations of the barometer, thermo-
meter, wet and dry thermometers, clouds, winds, meteors, &c, &c,
on four fixed days in each year: viz. 21st of March, 21st of June,
21st of September, and 2 1st December, (unless any of these days
should fall on a Sunday, in which case, for the 21st substitute the
22nd,) at the commencement of each hour, (per clock) mean time at
the place for 36 hours, beginning at 6 o'clock in the morning of the
21st, and ending at 6 o'clock in the evening of the 22nd. Sir John
Herschel himself adds, " If possible, get meteorologists in England,
and elsewhere, by land and by sea, over the whole globe, to set
apart these four days as great meteorological festivals, when every
man is to be at his post."

It is only necessary to add that a portion of the " Records" will be
preserved for the insertion of a summary of such correct registers as
may be kept in this country, on these days ; we hope that meteorolo-
gists will be up and stirring.

V. — Postscript to Mr. Walkers Paper on the
Adjustment of the Eye, 6fc*
Sir, Manches terMay Wth, 1835.

May I request that you will do me the favour to insert, in
your next Number, the following postscript to my paper " On the
Adjustment of the Eye, &c."

To make my account complete, I ought, perhaps, to have added,
that the converse of the proposition is also established by the experi-
ments which I have made with the optical instrument described ; for,
with a contracted pupil, distant objects are but obscurely represented
on the retina, and those only which are well portrayed are such as
stand out in strong relief. So that it is quite apparent that whilst
on the one hand a contracted state of the pupil renders near objects
distinct ; on the other hand, to obtain a correct picture of distant
objects, and more particularly a wide range of vision, it is essential
that the pupil should be rather dilated. With the instrument adap-
ted for the representation of distant objects, if it be desired to produce
a perfect picture of a near object by altering the relative position of
the lens and the retina, it is necessary to remove the latter to a
distance of not less than two inches from the former, That a corre-
sponding change of this description can take place in the human
eye will hardly be supposed.

I am, Sir,

Your very obedient Servant,

John Walker .
To the Editor of the u Records of General Science."
* See vol. i. p. 368.

472 Scientific Intelligence. [June

VI. — Optical Experiment.

The following is contained in a letter to the Editor, from Pro-
fessor Stevelly of Belfast.

" Mr. Patterson, a young gentleman of this town, of very consider-
able literary and scientific acquirements, and one of the Vice-Presi-
dents of our Natural History Society lately informed me that he
had been greatly surprised while walking past the iron railings of
our College, and at the same time looking through them at the snow
covered country, the sun also shining brightly, and being near the
horizon, to observe, that as the rails and open spaces came alternately
before his eyes, a very vivid play of colours presented itself to his
notice, the shades being chiefly reds and blues ; but he thought he
also observed other prismatic colours. On the next opportunity I
had, the snow, however, being only on the distant hills, I tried the
experiment myself, but as I walked at a slow pace, I was nearly sup-
posing that my eyes being very defective were not fitted to make the
observation, when I recollected that Mr. Patterson habitually walks
very fast ; I therefore quickened my pace very considerably, and was
much gratified at observing, after a few seconds; that very vivid
changes of colour did present themselves to my notice, but the pre-
dominant colour to me was a sjhade of pink, and some dark colours
which I could not accurately distinguish alternated with it. The
intervention of the opaque bars of the railing at equidistant intervals
was no doubt the cause, and the entire effect would seem to me to
prove that the retina takes different lengths of time to be impressed
with the several colours sufficiently for the notice of them to be con-
veyed to the mind, as also that the time during which the retina
remains under the influence of the impressions of the several coloured
lights after the light itself had ceased to act is different. If this be
the cause of the appearance I have attempted hastily to describe, it
can very easily be put to the test of accurate and direct experiment,
by an apparatus somewhat similar to the lately invented pleasing
illusion, the stroboscope."

VII — Prevention of Dry Rot by Corrosive Sublimate.
Sir,
Having seen a notice of Dr. Faraday's idea of the innocence of Mr.
Kyan's application of the deutochloride of mercury, when used as a
preventive of the dry rot in timber, may I solicit your opinion re-
specting the following queries :

1st. Will a ship built with timber, so prepared and sheathed with
copper, be deprived of such sheathing by the elective attraction be-
tween its atoms and those of the salt ?

2nd. Will there not be a succession of decompositions and of re-
compositions exerted between the saline matter of the sea the copper-
sheathing and the salt, and of these sufficient to excite a galvanic
action by which such preparation will be rendered inert ?
Remaining, Sir,

Your humble servant,

J. H. L.
Rugby, April 8, 1835.
To the Editor of the Records of General Science.

1835.] Scientific Intelligence. 473

As the permanency of the benefit resulting from the application of
corrosive sublimate to prevent dry rot from affecting the timber of ships
is matter of pure experiment, it would only be speculating to give any
opinion at the present time upon the subject. But as far as the expe-
riments have gone I have reason to know that the results have been
highly satisfactory, not only with regard to the preservation of the
timber, but also in reference to the health of the seamen, upon whom
it was supposed by some, on what grounds it is not easy to discover,
that the mercurial salt would produce deleterious effects ; neither is
there any reason for anticipating the detriment, which the queries of
my correspondent suggest, to the copper sheathing from the same
influence. — Edit.

VIII. — Mode of preserving Iron and Steel from rusting.

Several methods of preventing instruments of steel and iron from
oxidating are well known, such as covering them with mercurial
ointment, grease, oil or marrow, or placing them in calcined lime.
The former of these I have found the most effectual as well as the
most convenient mode.

M. Payen has, however, lately proposed a new plan for accom-
plishing the same object. He found that a saturated solution of car-
bonate of soda mixed with its own volume of water, disengaged only
ToW Parfc °f its volume of air, and preserved iron from rusting, and
did not lose this power even when diluted with twenty-five times its
volume of water. A saturated solution of borate of soda, as well as
a mixture of water and ammonia, disengaged no gas nor underwent
any contraction, but preserved iron from oxidating. Saturated lime
water diluted with an equal volume of water possessed the same
power. A saturated solution of potash diluted with 1000 and 2000
parts of water, preserved iron, but when saturated with a current of
carbonic acid, the oxidation of the metal occurred as in common water.
A saturated solution of potash diluted with 4000 or 3000 parts of
water, had not the property of preventing oxidation, and upon turn-
sol this solution exhibited an alkaline re-action.

M. Payen, sensible of the impracticability of immersing surgical
instruments in a liquid, suggests the propriety of forming a varnish
the saturated solution of potash, and gum tragacanth.

He made a comparative experiment upon muskets, one of which
he varnished over, and the other was left in its natural state. After
a lapse of fifteen days the former was quite bright, while the latter
was rusted. He considers thatthe solutions of soda will be preferable
to those of potash, because they are less deliquescent. The effects
of these solutions in preventing oxidation were so decided, that he
compared carefully the consequences when iron was placed in common
water. About 20 minutes after immersion a thin opaline halo sur-
rounds it, which increases in size and intensity. At the end of an
hour it is sensibly brown, and gradually a deposit begins to form on
the greatest part of the iron, and at the bottom of the vessel.

474 Scientific Jntelligence . [June

IX. — Communication by Egypt to India.

The subject of a short communication to India has been so much
before the public of late, that the following tables of distances will
not be unacceptable : —

MILES.

From Bombav to Aden . 1646

„ Aden to Suez . . 1323

„ Bombay to Socotra . 1 137

„ Socotra to Camaran 535

„ Camaran to Cossair 795

„ Cossair to Suez . . 270

MILES

From Alexandria to Malta 837
„ Suez to Quaherah . 70
„ Quaherah to Alexandria 1 20
„ Suez to Boulac . . 80
„ Boulac to Alexandria 185

DAYS.

Compare this with the route

Falmouth to Malta, with

by Cossair : —

2 days at Gibraltar .

16

DAYS.

Delay at Malta . . . .

2

Bombay to Aden . . . 10 J

Malta to Alexandria .

6

Delay at Aden .... 2

Alexandria to Suez

. 6

Aden to Cossair ... 6|

Suez to Aden . . .

§i

Cossair to Coptos ... 4

Delay at Aden for coals

. 2

Coptos to Boulac by water 8

Aden to Bombay . .

10|

Boulac to Alexandria . . 3

51

.„,„. . ™ . . 34*

(Wilkinson's Thebes.)

The number of days from England to Alexandria being 24, it
appears, from these computations, that the route from Alexandria to
Bombay, by Suez, would occupy 27 days, while by Cossair it would
require 34£ days ; but if steam boats were employed on the Nile
between Coptos and Alexandria, instead of the country boats as at
present, the latter route might be reduced to 29 days. The line by
Suez, therefore, has the advantage, even if this improvement were
made. We are inclined to recommend this mode of communication
as possessing advantages which neither the route by the Nile or
Euphrates possess. The latter will be attended with almost insu-
perable difficulties, and appears to us chimerical in the present
barbarous state of the country.

X. — JBotanic Garden in Japan.
The Dutch government has formed a botanic garden at Dogima
in Japan, which according to Dr. Siebold, contains more than a
thousand plants, collected from the Japan islands and from China.
In the garden, a memorial has been erected in honour of Campfer
and Thunberg. The students who were instructed by Thunberg
during his travels in Japan, have followed up the study of botany
with much zeal and assiduity. They study the science, particularly
in reference to its application to medicine.

Dr. Siebold gives instruction on medical botany, which is eagerly
sought after by the Japanese. He praises the aptness of the Japanese
in distinguishing plants. Sigi Letsyemon, the interpreter of Thun-
berg, left a son and grandson, who possess a herbarium which was
made by their ancestor with the aid of Thunberg. They possess a

1835.] Scientific Intelligence . 475

diploma, granted after a strict examination. The Japanese keep up
a constant commerce with the Chinese ; and obtain most of their
showy plants from China. — (Wickstrom*8 Jahrsbericht der
Botanik, 1831. 145, and Brandes' Pharm. Zeit. 1835, 2.)

XI. — Phloridzin, a new Substance.
Konninck and Stas give this name to a substance which they have
found in the bark of the wild apple, pear, plumb, and cherry. It
possesses a yellowish white colour, crystallizes in silky needles, has at
first a bitter and then astringent taste. It is soluble in water, very
soluble in alcohol and ether, without action on test paper ; soluble
without decomposition in concentrated sulphuric and muriatic acids.
The sulphates of iron colour its solution in water deep brown, ace-
tate of lead produces a copious white precipitate. Lime water,
ammonia, tartar emetic, corrosive sublimate, and isinglass have no
action on Phloridzin. ^-f Journ. de Chim. Medic i. 259, NS.)

XII. — Greatest ascents in the atmosphere.

M. Boussingault, in company with Colonel Hall, on the 16th of
December, 1831, ascended Chimborazo, to the height of 6,006 metres
(19,699 feet) the greatest elevation which has yet been attained on
land, Humboldt having been able to reach as high only as 19,400 feet.
M. Gay Lussac, in a balloon, rose to 22,900 feet at Paris. The
barometer carried by Boussingault fell to 13 inches 8 lines. The
temperature in the shade was 7*8 C (45'6" F.) This chemist thinks
it possible to live in ratified air. Thus, at a height almost equal to
that of Mount Blanc, where Saussure had scarce strength to con-
sult his instruments, young women may be seen in South America,
dancing during the whole night. The celebrated battle of Pinchinca
during the war of independence, was fought at a height, little infe-
rior to that of Mount Rose. The guides who accompanied Saussure,
assured him, that they had seen the stars in broad day. Boussingault
never witnessed them, although he reached a much greater altitude.
(Journ. de Chim. Medic, i. 33. NS. )

XIII. — J)iamonds in Africa.
Pliny says in his natural history, (lib. xxvii.) that the diamond
existed in mines in ^Ethiopia, between the temple of Mercury and
the island of Meroe. This precious stone was an article of traffic
between the Carthaginians and Etrurians. Heeren stated, that it
was brought by caravans from the interior of Africa, being extracted
from the earth in mines or from auriferous sand. According to M.
Vellecotte, an officer in the 16th French regiment, lying at Algiers,
and M. Peluzo, Sardinain consul at Algiers, diamonds' exist in the
auriferous sand of the river Wa del Kebir or Kumel (Ampsaga
of the ancients) which rises at the north-east extremity of the chain
of Atlas. The diamonds were found in November, 1833, near the
town of Constantine (the ancient Eitra.) M. Peluzo sent three of
these diamonds to France. They are now in different collections.
One of them is in the collection of the Royal School of Mines.
Another, in the museum of Natural History, and a third, in a large
private collection — {Blendes' Pharmaeeutische Zeitungl\S35. 9.)

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Overcast, strong wind, with frequent showers.

Overcast, with slight showers, evening rain.

Calm, A.M. partially clear, P.M. cloudy and lowering.

Calm interrupted by occasional gusts, sky overspread with hazy clouds.

Brisk wind with hazy clouds.

Strong wind, soft clouds in rapid motion, occasionally in black dense masses.

Heavy gale, partially clear, cirrostratus, soft clouds below in rapid motion.

Gentle wind, evening calm, (sometimes interrupted) fleecy clouds in motion.

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Calm, cloudy or overcast, tendency to rain.

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Brisk unsteady wind, noon overcast, tendency to rain, evening calm and clear.

Light wind, A.M. nearly cloudless, P.M. overcast.

Brisk wind, clear and fine, cumuli.

Gentle breeze, A.M. cloudy, P.M. partially clear, evening clear, wind rising.

A.M. sky overspread with a thin hazy whiteness, P.M. heavy clouds, showers.

Brisk wind, heavy clouds, with snow and hail showers, evening boisterous.

Brisk wind, A.M. snow and hail showers, P.M. heavy masses of cloud.

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INDEX.

PAGE

Acids organic, mode of detecting 78
Acidulous waters
Acoustics

Achromatism of the Eye
Agaricus campestris in India
Air, mean temperature of the
— composition of
Albumen, combination of with salts 213
Allan, Mr. J. on the cure of Erysi

pelas by pressure
Alum mordant
Amidine . . ...
Ammeline, composition of
Ammonia, muriate of in minerals
Andalusia, geology of
Andrews, Mr. T. on changes ii

the blood. . . _ .
Anthracite, composition of
Antimony, precipitation of .
Antimonial nickel, analysis of .
Apocrenic acid, characters of
Apocrenates ....
Arden limestone, analysis of
Argemone mexicana

283
98
458
335
105
109

452

7

198

319
341

31
266
114
271
120
194

96
331

Arsenic glance 272

Arseniate of iron

• of copper

273
274
272
159
159
459
458

Arsenical pyrites

Arsenious acid, antidote for

Arts improvement in the

As Roman value of

Ashmolean Society of Oxford

Atmosphere, greatest ascents in the 475

Aurora borealis, connexion of with

magnetism . . . .65
Azote, compounds of . .184
deutoxide of, absorption of

by salts of protoxide of iron . Ill

Barytes, some new minerals con-
taining .

bicalcareo carbonate of .

calcareo sulphate of.

— calcareo carbonate of .
3ulphato carbonate of

Baryto-calcite, composition of .
Barlow Mr. on steam boats
Barometer, height of at the sea .
Bear, a species of hordeum .
Becquerel M. his work on elec-
tricity . . . .66, 144

369
373
370
372
370
371
309
103
443

PAGE

Bell, Sir Charles, on the nerves . 310
Benzine, composition of . . 205
Benzoic acid .... 128
Berwickshire Naturalists' Club,

proceedings of the * . 393
Bigg, a species of hordeum . . 442
Bigge, Rev. E. T. on the natural

history of the wasp . . . 459
Bleaching .... 5

Block-printing . . . . ib.
Blood, on the . . . . 24

on changes in the j . 31

acid nature of . . 56

researches on . . . ib.

Bombay Islands, Geology of . 291

Brain, structure of the . . . 212

Brande Mr. on floorcloth . 396

Buckland, Dr. on the sloth . . 389

Cadmium, separation of from bis-
muth 117

Calcium,chloride of double salt of 129
Calculus from the kidney . 216

Calf, analysis of the blood of . 31
Calico-printing, on . 3, 161, 321
Caranja Island, geology of . . 334
Carbolic acid, properties of . 49

Cerine 203

Cerium, experiments on . . 416
Chabasite, analysis of . . . 267
Chaptal, M. biographical notice of 401
China, plants collected in . 218

Chyle, on the .... 424
Chloral, composition of . . 110
Chloroforme, analysis of . . ib.
Chrome iron ore . . . 273
Chromium, protoxide of in crystals 191
Coal, products of the distillation of 47

1 in Estramadura . . . 348

Cobalt, oxide of, separation of from

oxide of nickel . . .116
Colours, dischargers of . . 10

accidental, of certain solu-
tions .....

Comet of H alley

Copper, protoxide of, mode of pre-
paring .....
Creatine .....
Crenic acid, properties of . .
Crenates ....
Creosote

439
463

114
216
120
192
210

478

INDEX.

[June

Cyanol, properties of .
Cyanamide, composition of
Cyanilic acid, properties of
Cylinder printing .

PAGE

. 48
191

. 189
5

Danaite, composition of . . 270
Davy, Dr. John, on the torpedo . 306
Dalsland, hotany of . .216

Decandolle, M. his life of Desfon-

t. tines 241

on the order myrsineaj 386

Delagoa Bay, expedition to . 156
Desfontaines, M. biography of . 241
Diamonds in Africa . . . 475
Dischargers of colours . . 10

Dolomite, composition of . 349

Don Mr. D. on rubiaciae . . 387
Dry rot,' preservation of timber

from . . . . . 472
Dufrenoy, M. on the iron mine of

Rancie 78

on the Campan marble 79

Dysluite, analysis of . . 285

Eaine, analysis of 281

Earth, temperature of at various

depths .... 456

Egypt, natural history of .79

Electricity, on . . 99, 304

two theories of . 464

a cure in palsy . . 100

Electro-dynamics . . .152
Elephanta Island, geology of . 330
Equator, temperature at the . 1 07
Ergotine, mode of preparing . 202
Erysipelas, cure of by pressure . 452
Esenbeck, Dr. on Indian solaneae 385
Estramadura, geology of . . 341
Ether, formation of . . .210
Eye on the adjustment of to

vision . . . 368, 471

Faraday, Dr. on electricity, 153, 232,
304, 317.

on the pen manufacture 397

Fibrine of the blood . . 431

Floorcloth, manufacture of . . 396
Forbes, Professor, on the refrac-
tion and polarization of heat . 394
Formic acid, action of on metallic

oxides 124

Franklinite, composition of . 270

Gadolinite, analysis of . . 403

Gahnite, composition of . . 274
Globe, state of at its formation . 68
Globules of the blood . . 427
Gmelin, L. on the blood . . 56
Gold from Ural . . .276
Graphite, analysis of . . . 266
se, fresh water formation in . 77
Guilding, Mr. on naticidae . 389

PAGE

Gypsum, employment of in agricul-
ture 313

Hamilton, Mr. on the laws of mo-
tion 308

Hansteen, C. on the magnetic in-
tensity of the earth . . 60
Harris, Mr. W. S. on some laws

of electricity .... 228
Heat, transmission of through
bodies .... 45

repulsion of bodies by . . 250

specific of bodies . . 108

terrestrial . . . .70

— — refraction and polarization of 394
Hermann, R. on Eaine . . 281

— on the blood . . 55

M. C . T. on murders and

suicides in llussia . . 173

Herschel, Sir J. on meteorological

festivals 471

Ilumboldtilite, analysis of . . 268
Hydroboracite, composition of . 266
Hypochlorite, constituents of . 271

India, communication by Egypt to 474
Institution, Royal, lectures at the 236,
315, 396, 464
Iodoforme, composition of . .110
Iridium . . .118, 119, 276
Iron, mode of preserving, from

rusting . . . . 473

Iron, peroxide of mordant of . 9

Iron, sulphate of . . . . 130
Isinglass, purest kind of . . 239
Ivory, Mr. on Clairaut's theory . 308

Japan, botanic garden in . . 474
Jerusalem, present state of . 397
Junckerite, description of . . 268

Kirwanite, analysis of . . 219

Lardner, Dr. on H alley's comet . 465
Landseer, Mr. on a monument

from Syria .... 317
Lavas, formation of 73

Lead, vanadiate of . . . 274
Lead, zinco-carbonate of . 35

— >— separation of from bismuth 120
Leucol, description of .49

Lichenine, properties of . .201
Light, theories of . . . 305

on the dispersion of . . 463

Linnean Society, transactions of . 384
Lister, Mr. on currents in Zoo-
phytes . . . .311
Litharge, native .... 272
Lozenges antacid . . . 318
Llerena, limestone of . . . 348
Lymph, on the . . . t'J I

1835.]

INDEX

479

PACE

Macaire, M. on the effect of gases

on vegetation . . . 79
Maconochie, Capt. on expeditions

of discovery .... 155
Madder-red .... 14

on the culture of . 207

Magnesia, separation of fixed alka-
lies from . . . 114

protoxide of iron . . 268

Magnetism .... 149
Magnetic intensity of the earth . 60
Maize, native country of . . 159

Malic acid 126

Malt, on . . . .441

Manganese, peroxide of . .319
Manna of Mt. Sinai . . 461

Marsupial animals, anatomy of .311
Melam, composition of . . 185
Melamine, composition of . .186
Melanochroite, constituents of . 273
Melloni, M. on transmission of heat

through bodies . . 45, 236
Mercaptan, composition of . .110
Mercurial ointment . . .319
Mercury, freezing of . . .65

in Estramadura . 350

Meteoric stones .... 279
Meteorological Journal, 80, 239, 320,

400, 472.
Meteorologists, address to . 471
Mice, method of destroying . . 76
Microscopical objects . . 239
Mineralogy .... 265

Mitscherlich, C. G. on human

saliva ..... 375
Mordants .... 7

Muller, Dr. on the lymph, blood,

and chyle .... 424
Myricine .... 203

Needle, declination of the . . 102
Nerves, on the . . . 212, 310
Newport, Mr. on the sphynx

ligustri .... 313
Newton, Sir Isaac, on the publica-
tion of his Principia . . 462
Nitrification, phenomena of . .74
Nitro benzide, composition of . 206

Oil from potatoes . . .77

Optical experiment . . . 472

Osmium, native . . 118, 275

Owen, Mr. on the anatomy of

marsupial animals . . .311

Papyrus from Syracuse . . 458

Paraffine, properties of . .211

Paramalic acid . . . 127

Pastes, resist . . . .12

Pens, manufacture of . . 397

Pharmaceutical preparations. 160, 318

Phenakite, composition of . 268

PAGE

Philosophical Transactions . 228, 304
Phloridzin, a new substance . 475
Phosphorescence. . . .67
Picamare, method of procuring. 211
Picrolichenine properties of . 202

Pigment printing . . .329
Pittacal, description of . .54
Plagionite, composition of . 271
Platinum, native . . . 275

Play, M. F. Le, on the geology of

Estramadura . . . 341
Pleonaste. description of . . 267
Polarization of heat . . . 394
Polybasite, analysis of. . . 274
Porla Well water, analysis of . 121
Potash, bitartrate solubility of .131
Powell, Rev. B, on repulsion by

heat .... 250
on the dispersion

of light 463

Printing, calico . . 5

in colours . . .159

Pyrotartaric acid . . .127
Pyroxylic spirit .... 209
Pyrrol, properties of 48

Quetelet, Professor, his work on
Natural Philosophy . . .392

Radiolite, composition of. . 267
Rain, fall of at Glasgow in 1834 . 160
Rancie, iron mine of . . 78
Respiration, experiments on . 27

Richardson, Mr. T., analysis of

wolfram by .... 449
Rio Tinto, copper mines of . .25
Ritchie, Dr. on the theories of light 315

electricity 464

Rosolic acid, on ... 50
Roux, M. on the Natural History

ofEgypt 79

Royle, Mr., on the Lycium of

Dioscorides . . . 388
Rudberg, F., on the temperature

of the ground at various depths 456
Runge, F. F., on the products of

the distillation of pit coal . . 47
Russia, murders and suicides in 173

Saline springs . . . . 281

Saliva, on human . . . 375

Salsette Island, account of . 300

Scouler, Dr., on fossil crustacea . 136

Secale cornutum, sugar of . 196

Selenium, method of procuring . 112

Shells, deposit of recent . . 131

Silver in Estramadura . . . 351

chloride of reduction of 112

Singeing, process of . . .5

Skania, fossils of 218

Sloth, habits of the . . .389

Soda, artificial manufacture of . 116

480

NDEX.

PAGE

Songragne, water of . . . 282
Soultz, water of . . . ib.
Spain, journey in ... 19

Speaking, machines on . . 469
Spirits, on 222, 255

Spinelle, composition of . . 267
Sphynx ligustri, anatomy of . 313
Springs, hot .... 284

temperature of . . 107

Starch, experiments on . .196
Steel, Dr. A., on spirits . 222,255

analysis of gadolo-

nite, &c ^67

Sternbergite, composition of . 273
Strontian, baryto-sulphate of . 374

Struthiin . . . .203

Sugar of milk not in blood . . 60
Sulpho benzide . . . 206

benzoic acid . . .128

Sulphureous waters . . . 284

Tarn tarn, manufacture of . .117

Thomson, Rev. James, meteorolo-
gical table by

Dr. R. D. history and

analysis of vanadiate of lead by

notice of some recent

80

34

improvements in science 97, 184, 265

analysis of crucilite . 142

analysis of Kirwanite 219

analvsis of Wollastonite 220

Sketch of the geology

of the Bombay Islands . 290, 330

on malt . . . 441

Dr. Thomas, on calico-
printing . . . 3, 161, 321

on respiration . . 27

analysis of thulite . 92

Arden limestone 96

on dysluite . . 285

account of new minerals

containing barytes . . . 369

analysis of gadolinite,&c. 403

Mr.Thomas, on a deposit

of recent marine shells at Dalmuir 131
Thulite, analvsis of. \ . 92
Tiedemann, F. on the blood . 56

Tin, oxide of mordant . . 33
Tomlinson, Mr. Charles, on visible

vibration . . . 358, 433

on the accidental co-
lours of certain solutions on mer-
cury

Tormentilla officinalis, facts relat-
ing to . . . . .

Tungsten

Tungstic acid .

439

393
449
449

Uranium, separation of from cobalt 1 17
Urea formed without the aid of the

kidnies .... 60

Uric acid . . ■ \ . 191

Urns, ancient .... 394

Vanadiate of lead, analysis of . 34
Vaypi Island, formation of . 339
Vegetation, effect of gases on .79
Vermilion, similar to Chinese . 195
Vibration visible, observations on

358, 433
Virlet, M. on a fresh water forma-
tion in Greece . . . .77
Vitex trifolia. ... 33

Volcanoes 69

Volta, A. M. biography of . 81
Voltzite, composition of . . 274

Walker, Mr. John, on the adjust-
ment of the eye to distinct vision,
&c 368, 471

Wallace, Rev. John, meteorologi-
cal table by . 240, 320, 400, 476

Waters, acidulous . . . 283

mineral .... 281

Sulphureous . . 284

Wasp, natural history of the . 459

Wax, oil of . . . . 209
Wermland, botany of . . .216
Wheatstone, Mr. on the velocity

of light .... 307

on speaking machines 469

Wicklow, vanadiate of lead from . 48
Wolfram, analysis of . . 449

Yarrell, Mr. on the organs of voice
in the cygnus buccinator . . 388

on two species of Leuciscus 389

Yttria, experiments on . . 409

Zinc, chloride of a good caustic. 318
Zoophytes, currents in . . . 312

ERRATA.

p 20, / 3 and throughout, for Almeyda, read Almaden. p 31, 1 21, for nine, read
5|. p 31 , / 30, for somewhat more than half, read about one-third, p 77, / 34,
for Corniferae, read Coniferae. p 93, / 3, for while, read white, p 97, I 24, for
52, read 50. p 104, I 19, for 44, read 21. p 117, 1 16, for insoluble, read soluble.
p 130, / 17, for 2-563, read 1-99. p 158, / 38, for 300, read 3000. p 218, / 6,
for Neotna repettis, read Neottia repens. p 239, / 1, for microcoscopal, read
microscopical, p 285, / 10 from bottom, for immediatelv, read intimately, p 287
/ 1, for dried, read tried, p 359, I 28, for length, read levity, p 361, I 5, for
down, read between, p 361, / 26. for direction, read division, p 363, I 9, for
noise, read note, p 367, / 27, for annexed, read annealed, p 370, / 4 from bottom
and throughout, for Alsten, read Alston, p 393, / 4 from bottom, before Macro-
glossa, insert JJeilephila Gafii, hoverinsr like.

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