THE

\

INDIA REVIEW

’h '

AND

JOURNAL OF FOREIGN SCIENCE

EDITED BY

FREDERICK CORBYN, ESQ.

AS WE SHALt ALWAYS BE CONSCIOUS THAT OUR MISTAKES ARE INVOLUNTARY, WE SHALL WATCH THE GRADUAL DISCOVERIES OF TIME, AND RETRACT WHATEVER WE HAVE HASTILY AND ERRO- NEOUSLY ADVANCED. Johnson.

PRINTED AND PUBLISHED BY G. WOOLLASTON, AND SOLD BY MR. HUSBAND, ALLAHABAD ; MR. PHAROAH, MOUNT ROAD, MADRAS ; AND MR. MALVBRY, MEADOW STREET, BOMBAY.

9m^Bru

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4. £ Asia

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PREFACE.'

A year has now elapsed since we commenced the periodical the first volume «)f which is completed. The grounds on which we ventured on fthis scientific enterprize were not derived from a belief o^ our own fitness, for such an un- dertaking ; but from the circumstance that others, possessing superior talent, greater erudition, and being better adapted inv’every respect than ourselves, had not come forward: and when on the one hand, we took into consideration th® vast extent of this empire, and the strides which education was making among all classes of the people, and on the other, that no work, calcu- lated to diffuse the light which discoveries and improvements in Europe were hourly shedding through the medium of science and the arts, had been offered to the public; we considered ourselves justified in stepping forward, humble as our pretensions were, to prove the utility of a Journal exclusiv’^ely devoted to the review of works on science, embracing foreign science and the arts; and, by shewing the extensive influence which their dissemination must necessarily have in promoting the welfare of this country, and laying open those resources of knowledge which at all times have formed the basis of national power and prosperity, endeavour to awaken a general spirit of research. We had another objectinview. There are at the present moment rpwards of 700, accomplished and highly educated medical men scattered over the vast territories of our eastern possessions. The duties of many consist in simply attending'^4‘ew sick in a solitary hospital, and the British Government of India has not yet discovered the admirable advantages which would accrue from employing these able men out of the immediate sphere of their profession. Now there is scarcely a medical man in India who has not acquired some knowledge of chemistry — a knowledge which, it does not require much penetration and inge- nuity to prove, might be applied to improve the arts and manufactories now going on, in the great cities and marts in this country. What soil in the whole world is so rich in productions as this, and so calculated to yield all that is now obtained from foreign countries ? Observe what the genius of che- mical science has done for France and England, and what may it not do for India !

We are aware that we might be charged with encouraging an indulgence in speculative refinement, which has in some instances led men out of the line of useful industry, and, by the loss of property, to the ruin of their families. Such has been the result, it is true; but, generally speaking, to the artist only, seldom to the man of science. The chemist is better able than one who is only a mechanic to predict, from an experiment on a small scale, the probable issue of more extensive attempts. Watt, by a clear insight into the doctrine of latent heat, resulting from his thorough knowledge of chemistry, and seconded by mechanical skill, taught the way to bring the steam engine into

PREFACE.

perfecuon. Wedrrewood, by the same knowledge, advanced the arts of manufacturing porcelain ; neither must we forget Scheele’s discovery of oxy- genized muriatic acid, and Bethollet’s instructions in its application to the art of bleaching, nor Sequin’s and Davy’s chemical processes, which brought into perfection the art of tanning and preparation of leather. Chemistry is the foundation of those arts which furnish us with saline substances, an order of bodies highly useful in the affairs of common life. The success- ful manufactory of glass and various kinds of pottery depend upon a know- ledge of the nature of the substances employed, of their fusibility, as affect- ed by difference of proportion, or by the admixture of foreign substances, and of the means of regulating and measuring high degrees of heat. The chemist Bergman taught the most successful manufactory of brick and tiles. The art of malting is most successfully taught by the chemist. Dyeing and printing, as we have already shewn, are a tissue of chemical operations, and in short we should tire our readers by giving further illustration, to shew the utility of this department of our labours to medical men who are generally chemists. If national prosperity in Britain has arisen, in an eminent degree, from a superiority in the production of her arts, ought they, we enquire, to be neglected in British India? If not, we may boldly put the question — were we not, as having the welfare of India at heart, bound to promote it by a due discharge of our duty, by diffusing discoveries in the mechanical arts, among ihedical men as the means of communicating them to the natives ?

The character of our work differs however from any other of a similar kind in the variety of its objects ; possessing as it does the character of Thom- son’s Records of Science, and Jameson’s Philosophical Journal, it also assumes the appearance of the Mechanics' Magazine, and Repertory of Inventions and Arts, as well as a Review of Science in India, 'and Register of new di'^coveries. Our reason for giving to our periodical this character proceeded from our knowledge, that recently six Scientific Journals were published in Great Britain : these have been reduced to two; one of which is published monthly in London, the other quarterly in Edinburgh. Since 1835, an additional work has been published, viz., “ Records of Science ; and since then, another on Popular Science: how long these last ably-conducted Journals will exist, it is impossible to say; but it is obvious, there must be some cause for this want of success in works of science. We ourselves believe the cause to have arisen, from the articles having generally been too abstruse and subtle. It is true, they were full of refined and speculative knowledge and recondite reasoning; replete with physical and metaphysical sub^ jects; but, then they were more adapted to the deep thinking philosopher, than to the general scientific reader : hence a want of subscribers. This failure in Britain of periodicals which have been devoted solely to the diffusion of general science, was a warning to us to consider well the grounds on which we anticipated success in our new undertaking. In a country like India where

PREFACE.

iii

the British sojourners and their descendants are comparatively few, the means of education as regards science is but in its infancy; and therefore the import- ance of periodicals, purely on the mere abstract branches of science, is not felt. It is principally on this account that we determined to blend with purely scientific matter, articles on the mechainical arts, and such other interesting subjects as regard improvement in manufactures^ commerce, agriculture, &c„ in order to suit the taste and promote the benefit of all classes, by which we should be able to admit subjects which embrace abstruse investigation into the causes of physical changes, and determine the nature of bodies, reducing them to their elements, ascertaining their mutual actions and relation, and to apply the knowledge, thus ascertained by demonstrative science, to the improvement of arts which supply the wants as well as the comforts of life.

The grave philosopher and the man of science may not delight in articles of the former description ; but, by attending to our explanations, he would find that our object is to secure extensive circulation,tending greatly to support that portion of our work which is to be devoted to the latter articles which he de- sires to see. Our great object was to be the means of leading to important local and national improvements of promoting traffic by rivers, roads, and canals* by steam communication and rail-road transit ; in which to excite individual enterprize for large interest on capital, and to shew that such improvements call imperatively for the immediate attention of Government for liberal appro- priations. That stupendous machine, the steam engine, has already undergone* in its progress more than two hundred different modifications. It was our desire to give every new improvement in their motive forces from water, ether, alcohol, essential oils, the liquifiable gases, atmospheric air, &c. The prepara- tion of that invaluable and important metal, the chief material of nearly all machinery — iron, as well as the various manipulations and mechanism em- ployed in the great staple commodities, cotton, silk, woollen, and linen ; the construction of engines, mills, railways, carriages, ships, boats, docks, canals, bridges, furnaces, boilers, gas machinery, looms, presses, pumps, paddles, ploughs, water works, illustrated by lithographic sketches, together with an account of the various important processes of dyeing, distilling, bleaching, brewing, and tanning. While to the chemist and mechanic we hope to be of essential service, we shall do our utmost to meet the wishes of the natura- list. The extravagant price of standard works in this department has been to discourage the naturalist in his interesting study. We have been able to glean from the numerous works which have been published, and from papers in the transactions of learned societies during the past year, all that is novel and valuable for this class of our readers.

The question remaining to be considered next is, what benefit will such in- telligence afford to a country like this, containing 1,116,000 square miles, equal in size to Great Britain, France, Spain, Portugal, Italy, Germany, Hungary, Poland, and Turkey, put together ; the number of people who inhabit it being computed at 100,000,000 souls. When the riches of other countries have

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PREFACE.

been ascertained and made known through the chemist and geologist, may we not reasonably expect that they will excite a spirit of enquiry, and a desire for scientific education in the people here ; and that they will soon learn that this is the largest empire in the world, — the repository of the most valuable and precious ores, — the greatest repository of diamonds hitherto discovered; a country rich in spices, drugs, colours, silk, cotton, saltpetre, saffron, coffee, sugar, rice, &c. ; that its manufactures in silks, embroidery, and cottons, have long since excited the admiration of Europe ; that its animal and vegetable pro- ductions, its metals, minerals, and valuable natural productions are scarcely yet known ; and that science and the arts have yet to develope these internal re- sources, which will ere long raise its character ? Is it extravagant to hope under British rule that it will become the greatest commercial nation in the world?

The realization of these objects, however, depends materially upon the policy which the government of India may adopt in regard to its revenue. \¥hether it endangers manufactures and population, or whether with the constant exten- sion of boundary it takes measures to improve the soil, realize millions of acres which are now covered with forest, brush-wood, and stagnant waters ; j whether it facilitates inland navigation, by deepening harbours, constructing 1 docks, and encouraging ship-building, — the whole depends upon the adoption of a system of national policy, by which the advantages to the Government and ^he community may be reciprocal. It is during the times of peace that the great work of national improvement should go on, not as a matter of expedi- ency, but of positive necessity. If we desire to erect the fabric of our rule and future prosperity on a permanent basis, while we are giving encouragement to trace out the unexplored gifts of nature and bring into action the hidden trea- i sures of the land, we must concilitate public regard, by promoting the pros- perity of the people. A specific sum might justly be appropriated to objects of national improvement, which, besides giving encouragement to ingenuity i and merit, and employment to the industrious, would promote the circulation '

of the specie throughout the country; increase the demand for various articles |

of inland manufacture ; and finally produce in their operation an annual equi- ' valent equal to the whole amodht of the original outlay, and most probably i exceed it.

But we must hasten to a conclusion — we have only to state how far our views have been supported ; this may be seen by the size of our publication and numerous plates which embellish it. It commenced with 32 pages and has pro- gressively increased to 64, without additional cost to subscribers ; and we trust, so I soon as we experience a mitigation in the post office regulations, we shall be able to add numerous improvements, tending not only to increase the interest but the value'of the work, on receiving additional support, which is essential to bring to perfection a periodical of the kind we have described.

)V, )

FOREIGN SCIENCE AND THE ARTS.

EMBRACING MINERALOGY, GEOLOGY, NATURAL HISTORY,

PHYSICS. &c.

MINERALOGY.

PLAGIONrf E.-Tiie crystals of this mineral belong to the obliqae 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 trnncatures of the anterior angles. They are implanted in quartz. Fracture conchoidal. G. Rose has termed it plagionite, from (^jfXayw^ obli- que) in consequence of the oblique form and inclination of the axis, which measures 107^ 32'. It consists, accordinor to Rose of Lead 40‘..52 Antimony 37.94 Sulphur 21.53, Total 99,99.

Besides simple sulphuret of antimony, in the Wolfsberg antiraonial veins, there are a great many combinations of sulphuret of anti- mony and sulphuret of lead in ditferent pro- portions, viz ; zinkenite, 3 Sb. su. “L Pb. su. Plagionite, and Federerz, Bournonite. The; two first have only been found at Wolfsberg. f Poggeiidorjf, xxviii. 421 .)

16. NATIVE LITHARGE has been found half way up the volcanoes of Popocatepetl and Iztacictualt in Mexico, corresponding exactly in appearance and composition with that derived from the lead furnaces, (Ann, des. Mines, vi,)

17. ARSENICAL PYRITES has been analyzed by E. Hoflinann from four locali- ties :

	Schnee- berg.	Slaclming.	Hartz.	Reichen- stein.
Sulphur . .	0.14	5.20	1 1 .05	1.94
Copper . .	0..50		99	99
Bismuth . .	2.19	60.41		65.99
Arsenic . .	71.30	.53.60
Nickel . . .	28.14	13.37	30.02	99
Cobalt ....	,,	5.10	0,56	28.8
Iron	,,	13.49	3.29
Serpentine				2.17
	102'27	97.57	98..52	98.18

the Uralian Mountains, in limestone, 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 7o.36 Chromic acid 23.61, Total 100.00.

It is obviously, therefore a subsesqui-chro- mate of lead. ( Poggendorjf, xxviii.)

21. CHROME IRON ORE, from Balti- more, was found by Abich to contain, (Pog- gendorff, 1831.)

Silica	Crystallized.	AmorpliouJ 00.83
Alumina	... 11.85	13.85
Oxide of chromium	.. 60.04	51,91
Protoxide of iron..	... 20.13	18.97
Magnesia		9.96
Total	. . 99.47	98.52

22. WHITE ARSENI ATE OF IRON,— Kersten found a specimen of this mineral from Freiberg, to consist of Arseniate of iron, 70,70, Water, 23.50, Total 99.20. (Schweig- qer Seidel’s Jahrhuch, vi. 182.)

23. POLYBASITE. — H. Rose has ana- lyzed this mineral from the following locali- ties

Guarisamny,

Mexico. Scliemnitz. Freiberg.

Sulphur 17.04

Antimony . 5.09

Arsenic 3.74

Silver 64.29

Copper. .

Iron. . . . Zinc. . . .

9.93

0.06

0.00

16.83

0,25

6.23

72.43

3,04

0.33

0.59

16.35

8.39

1.17

69,99

4.11

0,29

0.00

18. ARSENIC GLANCE.-Karsten found

the composition of a specimen from Marien- berg, in Saxony Arsenic 93.785 Bismuth 3.0 tl Total 99.786. (ScJiiveig. xxiii. 390.1

19, STERNBERGitE.-Zippa finds this composed of Silver 33.2 Iron 36.0 Suh)hur 30.0, Total 99,2, equivalent to 4 F Su. + Ag. Su. (Poggendorff) Ann. xxvii.)

20 M ELAN OCHROITE.— This mineral is found in the neighbourhood of Bere.sow, in

Total.... 100.15 99.70 100.30

(Poggendorjf, xxviii. 156.)

24. VOLTZITE — This mineral is found at Pont Gibaud, in Puy de Dome, It pos- sesses a pearly lustre ; colour rose-red, or of yellow ; granular ; fracture irregular ; softer than glass ; sp. gr. 3.6B. It consists of Sulphuret of zinc, 82.92, Oxide of zinc, 15.34, Peroxide of iron, 1.84, Total 100-10. (Pog^ gendorjf, xxxi.)

25. CARBONATE OF LEAD AND ZINC, comes from Mount Proxi, iri Sardinia in the form of small crystals, irregularly grouped together in rock quartz ; white and translucid ; hardness equal to calcareous

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RECENT DISCOVERIES IN MINERALOGY.

spar ; sp. gr. 6.9. It contains Carbonate of lead, with traces of chloride of lead 93.10, Carbonate of zinc, 7,02, Total, 99 12. (Jahrbuch, 3o?, 1833, p. 333.)

26. G A UNITE, according to the analysis of Abich, consists ofSilica,3.8f, Alumina .35.14 Magnesia, 5.25, Peroxide of iron, 5.85, Oxide of zinc 30.02, Total 100.10.

The specimen was from Fahlun.

27. BLUE ARSENIATE OF COPPER, from Cornwall, consists, according to Trolle Wachtmeister, ofOxide ofCopper, ^3. 19, Alu- mina, 8.03, Peroxide of iron, 3,41, Arsenic acid, 20.79, Phosphoric acid, 3.6 1, Silicaand quartz, 6.99, Water, 22.24, Total 100,26, (Jahrhuch, 1st, ’833. p. 73.)

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 I831-33, the two first weighing 8 kil. (17 lbs 1 1 oz. and thethird5kils. 11 Ibs.loz.l dr.) It is accom- panied with gold,osmium,iridium, magneticiron, chromium, brown oxide of iron, oxide of titani- um, epidote garnet, rock crystal, and sometimes diamonds. The sand is composed of jasper, quartz, andgreenstone, and likewise small yel- low crystals of rhomboidal, dodecahedrons, re- sembling 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. (Jour, f/e St, Petersburg, 1833)

29. OSMIUM AND IRIDIUM.— Two minerals have been obtained 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 hexago- nal prism. It possesses a blue metallic lus- tre. Hardness nearly that of quartz.Sp.gr, 39-386 — 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 Bi- limbajewsk and Kyschtim, and several other places in the Urals. The crystals of the va- riety from Nischne Tagil have the same form as the preceding. The colour is bluish-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 looses its lustre, and disengages a pungent smell 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 iridi- um, possessing the same shape, G. Rose con- siders 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 oWious that Berzelius’ sp. gr, 10 is quite er- roneous. ( Poyyendorff Ann. xxix,4o2.)

30. NATIVE IRIDIUM has been found at Nischne Tagil, accompanied with gold and platinum. It is in grains of the colour of sil- ver, 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,;

31. CHEMICAL COMPOSITION OF NATIVE GOLD, PAR FICULAI^LY UR- ALIAN 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 Kons- berg, in Norway, which consisted of 28 gold, 72 silver in the 100 parts. Klaproth obtain- ed gold from Schlangenberg in the Altai, 64 gold, 36 silver ; and Lampadius, from an un- known locality, procured 96-6 gold, the re- mainder being silver and iron. Boussingault analyzed gold from difterent places in Colom- bia, and found it combined with silver in vari- able quantities, but always in difinite propor- tions, 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 Humboldt, made a collec- tion of gold ores for the purpose of deter- mining the truth of the French chemist’s po- sition.

In the Uralian Mountains, gold is found in rocks and distributed among sand. Previ ms to 1819, it w'as extracted from rock veins, but after this period, the discovery of sand containing it occasioned the abandonment of working the I’ock mines. Gold in rocks is found always in quartzose veins : atBeresow, occurring in the form of crystals, and at Newdansk, in plates, while at Czarewo Alex- androw'sk, pieces are met with which weigh from 13 to 24 livres, (18 lbs. to 9Q lbs. troy.) Gold produced by the different workings is assayed in the mints of Katharinenburg, and St, Petersburg.

The following table exhibits the composi- tion of gold from different localities, all being richer than gold from Colombia and Siebeu- burg:—

	1	Gold.	Silver.
Katharinenburg . .	sand	93-01	6-99
Hiel	rock	87-40	12-60
Miask	sand	93-0	7-00
Bogowslowsk	—	88-80	11-20
Kuschvva	—	90-30	9-70
Werch Isetsk ....		92-70	7-30
Nischne Tagil	—	90-73	9-27
Kaslinski		91-97	8-03
Newiansk		91-42	8-58
Do	rock	92-95	7-05
Sisersk	sand	91-78	8-22
Ulaley		91-45	1 8-55
Schaitansk		95-10	4-90
Biiimbajeusk	—	93-54	6-46
Do		91-24	8-76
Bewdinski		93-33	6-67
Usewoledski . . , . . .	I	89-01	10-99
Bissersk |	— 1	88-72	11-28 i

IMPORTANT CONSEQUENCES DEDUCED FROM ANALYSES OF GOLD. 3

Before the blowpipe, pure gold and pure silver are readily distinguished by their fus- ing into a transparent and colourless glass, with salt of phosphorous in the exterior flame. In the interior flame, if the quantity of silver is small, the glass is opaline and yel- lowish, but if great, altogether yellow and opaque. The native allo5's ant in the same manner, but an alloy which contains only ^ per ceut. of silver has no action on salt phos- phorous.

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 that a saturated solution of gold does not dis- solve a notable quantity of chloride of silver ; the second, on the contrary, deposits a con- siderable 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. Eva- porate the liquid in a porcelain crucible, to drive otf the excess of chlorine, and when fumes cease to be given off, treat it with oxalic acid. Place the liquid in a glass de- fended by convex cover, in order that no gold may be mechanically removed with the car- bonic 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 sulphuretted hydrogen through the solution of the residue in muriatic acid. A trace of cop- per 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 i.s sustained to a small ex- tent in this way, and G. Rose, to obviate the inadequacy of this plan, tried a number of others, and at last hit upon one which he con- siders better than any other yet devised. Fuse the native gold in a small porcelain cru- cible with lead, by means of a lamp supplied With a double current of air. Digest the mass in nitric acid ; detach it from the cru- cible, 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 chloride of silver dissolved, diluting the liquid with water ; filter the li- quor and evaporte to dryness. Dis.solve in water, and precipitate the gold by means of muriate of iron. Sulphated protoxide of iron does not answer for the precipitation, 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 drecipitate part of the lead in the state of

B 3

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 mi- nute portion 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 imoortant consequences.

1. ■ Native gold does not contain gold and silver in definite proportions.

2. Gold and silver being thus combined in indefinite proportions, he concludes that they are isomorphous, an inference which can- not be deduced with the same certainty from the identity of their crystals.

3. Native gold always contains silver, cop- per, 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 minex"al.

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 loca- lity vary in composition.

6. Gold found in veins varries in different parts of the same mine.

7. He finds that the gold from sand con- tains 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 government, for the mining of gold has entirely yielded to the process of pro- curing it from sand. (Poggendorff Ann.)

STATE OF THE GLOBE AT ITS FOR- MATiON.

BY M. BECQUEREL.

(Continued from j.age \53.) TERRESTRIAL HEAT.— The facts with which we are at present acquainted tend to prove that every place on tlie surface of the globe has an invariable mean temperature. The mean temperature of the equator is be- tween 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. A Melville Id. the mean heat was — 18*^50., while in the open sea it was — 8° 3. Calcu-

lating from these data, the temperature of the pole would be— 25^ or 30'^.

It is remakable that those places which are situated on the same isothermal line do not present the same vegetable productions. Hence, some have divided climate into con- stant, where the temperature is steady dur- ing 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

4

THE FORMATIONS OP WHICH THE GLOBE IS COMPOSED.

and the observation has been confirmed, the heat being determined to be 11^ 82 (53^* F.) Cordierhas 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 P for every 25 to 30 metres.

M. Fourier lias demonstrated that the cool- ing of the globe, i/s«c/r a fact is admitted, must be very slow, being less than

of a centigrade degree for a century ; and he has drawn these consequences: 1. All the heat below a particular point where the temperature is steady, has been possessed by the earth from its commencement. 2. This heat is intense in the nucleus, and at a cer- tain distance from the centre it begins to di- minish by regular laws up to the steady point, 3, d'he 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 derived from the interior cannot appreciably modify that of the surface.

Idumboldt has observed that in Mexico the decrease of temperature is not pi’bpor- tional to the height ; and Boussingault has found that in twenty-three years the sources of the Mariara have increased in tempera- ture from 59° 3 C, to 64° ; and those of Strin- cheras, from 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 0°. At the equator the ocean’s sur- face is hotter than the air ; but at the poles the reverse is the case.* Between the tro- llies, the heat diminishes with the depth; on the polar seas it diminishes as we descend.

Such are some of the principal circum- stances bearing upon terrestrial 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 spe- culating upon the method in which it was consolidated, applying known agents to the explanation of volcanic phenomena, and tracing out a sketch of the facts which have been ascertained in reference to terrestrial heat. He first notices alluvial deposits which are in process of formation, consisting of peat, marls, graval, stalactities, pisolites, and tra- vertines. 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 carbonate 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 tra- versing 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

* In lat. 28 9' N., long. 20a 33 W-, I found the temperature of the Atlantic Ocean 79°5, that of the air being 79® ; and in 2-20 S. L., 59^5' E. L. the thermometer stood in the air at 80°, and in the Indian Ocean at 88«6, — Edit.

\vithout consideration would infer. The Carlsbad water discharges annually 740,884 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 frorn the earth’s surface, fl he origin of the ocean’s saltness has at- tracted 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 proxi- mity of rivers ; thus, the Baltic and the Black Sea are weaker than the occean, and still more so than the Mediterranean.

From Boussingaull’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 volca- noes 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 substances, and the sulphuretted hydrogen may derive its origin from the re-action of the vapour of water upon sulphui’et of sodium.

The rocks of the tertiary formations are in general calcareous and silicious with a pre- dominance of magnesia, especially where the gypsum appears. Under this head are in- cluded the new formations characteidzed so happily by Air. 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 ti'ansition rocks, the coal, according to Deluc, has been foi’med at a slight eleva- tion above the sea like turf, and has been submer ged and covered by the sand of the ocean. If these waters are supposed to Imve borne along with them earthy matter of an elevated temperature, an explanation will be afforded for the absence o f animals in these rocks. The water under which the coal was formed must have possessed the property of holding iron in solution, as is ap- parent from the quantity of iron-stone which usually accompanies 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- mary. The porphyries, euphotides, or com- pounds of jade and diallage, serpentines, black porphyry, or ophites and dolomitess, are more variable in their position.

Among volcanic products the trachites are considered most ancient, and are sometimes startified. The traps, or basalts afford many minerals; the lava group contain also many species. Both HStna 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 YEINS.

o

DECOMPOSITION OF ROCKS- VEINS. — According to Becqueiel, veins are not to be considered as products of one general cause, but of a concurrence of several causes. The viens in the most ancient rocks are smaller than in the newer rocks, the largest existing in the schists and transition limestones. Wer- ner considered that rocks were decomposed by two acids : I. By carbonic acid as when granite and gneiss or felspar alone are decomposed and form kaolin, 2. Sulphuric acid derived fiom pyrites, as in veins of fels- p r, mica, and amphibole. Arsenic acid he considered produced a similar effect.

M. Fournet, who has paid much atten- tion to veins, distinguishes two kinds: those of igneous origin, such as porphyries, tra- chites, &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 depo- sited 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 observe.d four other epochs. At the second period new branches were formed, which were filled with secondary and tertiary products, especially quartz, but likewise sulphurates, which have formed alternating zones of pyrites, galena, and hyalines quartz in small crystals. A third period distinguishes a dilatation which disturb- ed the sources of the galena and introduced solutions of sul pirates of barytes- At the fourth epoch, the inerusting power of these sources appears to have been enfeebled, when parites and minute veins of carbonates were deposited. The fifth epoch was contempo- rajaeous with the basaltic eruptions. It is obvious, that for an explanation of the mode in which these veins are filled, 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, ga ena is gradually converted into a black pulveru- lent 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 attri- butable to hydrogen which condensed in its cavaties,

GRANITE, — Saussure attributed the de- composition 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 potash disap- pearing and silicate of alumina remaining. Felspar is probably one of those bodies whose particles are placed in such intimate union that acids have no effect upon it until it be exposed to electro-chemical agency. Four- net 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, pre- senting all the characters of a perfect granite, but falling to pieces when touched. Me ac- counts for the successive decomposition from the surface, internally to dimorphism, which has changed their crystalline texture like ar- ragonites and laumonites, Gustav. Rose has produced pyroxene and amphibole as in- stances of this dimorphism, of which some result from rapid, others from slow cooling. The theory of the felspar decomposition Four- net sums up shortly, 'i’he iron is peroxidized, 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 cry- stals of hyaline quartz, iorites, agates, opal, calcedony, and silicates, as chabasite, me- sotype.

I'his theory, however, rests upon two sup- positions which have not yet been demonstrat- ed. 1. That igneous rocks do not acquire a state of permanent equilibrium, and that they exhibit in the course of time an effect of di- morphism, and 2. 'fhat carbonic acid is ab- sorbed by tliese 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