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No. 1. No. 2. No. 3. p. The copper combined with carbonic acid being, . . 30'2 39'5 l8'3_ q. will require water to hydrate it, .. . . .. . . . .. . . . . . 4'2 5'5 2'6‘ The excess in b may have been carbonic acid, partially driven 0E. The chemical composition of the three minerals may therefore be thus expressed: N0. 1. No. 2. No. 3.
Hydrated carbonate of copper, .. .. .. .. - . .. .. .. .. .. 52‘4 68'5 3l'7 Sulphuretofcoflier,............................. 0' 0'? 63'0 Sulphuretofiron,............................... 2'1 12'4 0'0 Oxide ofiron, silex, &c... .... .. . . . . - ........... .. 43'5 25'! 5'3 Lossorexcess,..........»....-..."...--.-....... 2'0 —6'0 0'0
100-0 100-0 100-0
The excess in No. 2, is doubtless owing to the irregularity of the rocky admixture in different specimens, whereof one yielded 44, and another only 13-9 of insoluble matter, on digestion in acid.
The richness of the last of the three minerals will more than compensate for the increase of trouble and expence in the reduction of the ore by successive roastings; and practical miners assert, that the
glance or grey sulphuret is a much steadier and more plentiful ore than the carbonate.
I should add, before concluding the above imperfect analysis of the Nellore copper ores, that I tested them in vain for silver and other metals. Neither did arsenic appear to be present.
I may here mention, that among the specimens of minerals presented to me by Mr. Kama, as occurring within the copper mining district, associated with the micaceous schist, are the following; corundum and adamantine spar, garnets, dark-green actinolite, red chalk, manganese; besides carbonate of magnesia, and other minerals of which specimens have not yet reached me. An ore of mercury is also suspected to exist in the same range of rocks. The surface of the gneiss or micaceous schist, where exposed to the air, is frequently seen tinged of a green colour, from the trickling of water holding carbonate of copper in solution, through crevices of the rock.
Copper Mines of Singluina, in the Shekziwati country.
I take this opportunity of acknowledging the receipt of further specimens of the ores of these mines from Colonel S'rAcY.—They consist of the yellow and grey sulphurets, carbonates, and the blue native sulphate in deliquescent crystals. The latter is probably produced from the pyrites; as is the sulphate of iron from its sulphuret. Both of these occur also at Singhzina: the sulphate, from its difg ferent tints, having the native names of pila and ham kasz'.9, 91
yellow and green vitriol. There is also among the specimensamungya
kasis, which appears to be a compound of alum, and the sulphates of iron, and copper. There are two very beautiful specimens of virgin copper in mammellated concretions, coating oxide of iron, which appear to have been formed by a natural decomposition of the blue soluble sulphate on coming in contact with the iron ore.
A full description of the Singhfina mines, and the mode of extracting and working up the ore, (by Captain Bolnsnu, of the Engineers P) is printed in the third volume of the Gleanings in Science, page 380. It does not appear from that notice, that any previous roasting of the ore is resorted to ;but instead of this process, the ore is ground to a fine powder, formed into cakes with cow-dung, then burnt in a “ clamp," and lastly, mixed with scoria of iron to be blasted. The iron in this operation, deoxidated by the charcoal, doubtless assists in removing the sulphur from the copper by its superior affinity. The metal produced from these mines is, however, not thoroughly refined ; but according to Captain Borumu, is brittle, and of a lilac colour : while that of Basziwar in the Bliartpur district, (most probably a carbonate) is at once melted down into a fine malleable metal—but on the other hand, the latter is too poor an ore to be worked profitably.
The extent to which the She/uiwati mines have been worked in former ages of Hindu prosperity is fully equal to that we have seen of the Nellore mines, and strikingly similar in every respect. “ The scoriae, or khangar, that have been accumulating for ages, have at length formed a line of small hills, several hundred feet in length, and from thirty to sixty feet high: there are four insulated stone bastions built on ore of these artificial mounds. The rocky ridge in which the excavations have been carried on for generations is pierced by numerous shafts, giving access to the galleries, by which the hills are honey-combed in every direction to the length of a lms, if the natives are to be believed.” But I must refer to the article whence these paragraphs are quoted ; for the whole account will be read with interest.
I am in expectation of further specimens of the She/cziwati minerals from Mr, DEAN.
Ajmfr Copper Mines.
A new locality of copper ore has recently been brought to notice by Captain C. J. Drxotv, in the neighbourhood of Ajmir, where three difl"erent shafts have been opened. Specimens of the ore extracted thence were forwarded to me by the present Governor General, along with a copy of the report from Captain DIXON, on the subject, dated 8th May, 1835, from which I extract the following particulars :
" The Ajmir ore in mineralogical phraseology is ‘termed a ferrugenous red oxide of copper,’ and being free from sulphur, two operations are sufficient to metallize it ; one smelting, and one refining. The ore in Shekdwati, as well as the principal ores worked in Cornwall and Wales. are sulphurets, copper pyrites. They require successive calcinations, roastings, and smeltings ; eight separate processes being essential to perfect metalisation. At the same time, that our operations are conducted with celerity, and consequently at a comparatively small outlay ; inasmuch, that the ore, on the third day after it has been dug from the vein, is reduced to a metallic state, adapted for sale ; (while in Europe calcination alone occupies several months,) the business of smelting is wholly free from that noisomeness, so injurious to health, which characterises works of this nature at home, when sulphur forms an ingredient in the chemical composition of the ore.
“ The first vein was opened near Gligra, four miles N. N. East of Ajmir. It runs north and south, and its breadth varies from a span to four inches. It is situated on the plain, within one hundred and fifty yards from the range of hills; its greatest depth being sixty feet from the surface. An admixture of ores from separate veins is essential to a complete fusion ; and with this intention, a vein was sought and opened at Réjgarh, twelve miles S. S. West of this. This vein, also on the plain, but near the hills, is only twenty-five feet from the surface, while a third has been opened, within the last fifteen days, near Rajduri, ten miles south of Ajmfr. The presence of copper has been detected at other spots : indeed, it is beyond doubt the whole of the Ajmir valley is traversed by veins, which run from Kishengarb to Rdjgarb, a distance of thirty miles; industry and capital being the sole requisite to their complete development. In Cornwall, good veins are not met with, until attaining a depth of three hundred feet and upwards. At present, our labours are confined almost to the surface. The transmission of these specimens will, I hope, prove so far useful, that should the Honorable the Governor General be pleased to make them over for analyzation to some scientific gentleman in Calcutta, their intrinsic value as ores will be ascertained ; for though the studies of thelaboratory be as widely different in their issues from the labors of the furnace, as theory is from practice, still a favorable result in the former will be highly satisfactory,and may at a future period warrant the establishment of the works on a large scale. In exemplification of the observation in reference to theory and practice, various specimens treated in the study yield from twenty to eighty per cent., while the average produce of the mines in Cornwall for some years past has ranged from eight and a quarter to
-or veins in quartz and a. micaceous schist.
ten per cent. of metal. The reason is obvious. , In the small way, assorted specimens are selected, and by proper care and attention_ to their treatment, every particle of metal is recovered. But in the _l‘a.1-"gs way, in the smelting furnace, rich and poor ores with a good deal of extraneous matter incorporated therewith are fused together. Hence the result of the_ furnace always falls short_ of the issue of experiments in the study.”
Captain DIXGN is quite correct as to the fallacy of trusting to the results of the laboratory in regard to the average produce of mining operations. The nature of the ore, and of its associated minerals, is all that the chemist can pronounce upon. In this respect, the Ajmlr ores, like those of Bhartpur, hardly offer much encouragement: none of the specimens, small as they are, consist of homogeneous ore, but are in general, merely coatings oficarbonate on a ferruginous matrix, It is probable, however, that small cabinet specimens would be selected for this very object of shewing the connection with other rocks, and that far richer lumps are taken to the smelting house.
The ore from Rdjgarh, twelve miles S. S. W. of Ajm-fr, is accompanied with slender prismatic crystals of selenite, of black augite, hydrated red oxide of iron, and carbonate of the same metal. There are also veins of an aluminous or silicious malachite, which may be termed turquoise copper are ; it is of a fine blue colour, translucent where thin, breaking with conchoidal fracture, and. apparently capable of being converted to ornamental uses. It differs from the turquo_ise*, in being insoluble in acids, which take up only the green colouring matter, a carbonate of copper. I have not further analysed At Rdjauri, ten miles S. W. of Ajmir, the carbonate is of a lighter colour, more earthy, and accompanied with small yellow scales of mica and iron. At Gzigra, four miles N. N. E. of Ajmfr, the malachite is associated with carbonate of lead, a micaceous carbonate of iron, and with a rich galena or sulphuret of lead. Yellow copper pyrites alsopshews itself, and earthy veins of a pale blue, very similar to some of the streaks in the turquoise rocks of Nishapur, in Persia. It is possible that this mineral itself might be met with, on farther search, if felspar or other aluminous minerals exist in the Ajmfr hills : the matrix of the turquoise is also a red iron clay ore, very similar to that of the copper mines.
this curious mineral.
* See analysis of this mineral in the Gleaninge in Science, 375.
VIII.—-Proceedings of the Asiatic Society.
Wednseday Evening, the 4th November, 1835.
Captain Psusnwrow, Senior Member present, in the chair.
Esq., proposed at the last meeting, were ballotted. for, and unanimously elected Members of the Society.
Read a letter from Lieut. W. C. Bsxnn, acknowledging his election as a member.
Read a letter from '1-‘nouns DIGKENSON, Esq., Secretary Bombay Branch of the Royal Asiatic Society, acknowledging the receipt of a copy of the Index to the Asiatic Researches.
Read a letter from Cluanns Koma, Esq. Foreign Secretarv to the Royal
Society of London, acknowledging the receipt of a copy of’ M. Csomn DE K6aos's Tibetan Grammar and Dictionary.
Library. The following books were presented:
Proceedings of the Geological Society of London, N0. 39—by the Society.
Madras Journal of Literature and Science, No. 9, October 1835-—by the Madras Literary Society.
A Treatise on the manufacture of Saltpetre, descriptive of the operations and
proper plans to be used for the manufacture of Culmee and Cooteah-by Mr. J. Stephenson, and presented by him.
The Indian Journal of Medical Science, No. 23-—by the Editors.
The following books were received from the Oriental Translation Fund:
The Chronicles of Rabbi Joseph Ben Joshua Ben Meir, the Sphardi. Translated from the Hebrew by C’. H. F. Bialloblotzlcy, vol. 1. Miscellaneous Translations from Oriental languages, vol. 2nd. Les Aventures De Kamrup, par M. Garcin De Tassy.
Harivansa, or Histoire de la Famille de Hari, part 1st—by M. A. Lzmyloia. Ethiopic Didascalia, or the Ethiopic version of the Apostolic Constitutions
received in the Church of Abyssinia, with an English translation—by Thomas’ Pelt Plat, Esq., F. A. S.
Nipon 0 Dai itsi Ran, ou Annales des Empereurs du Japon, 1 vol.—by M. J. Klaproth.
Lardner’s Cabinet Cyclopedia, Swainson's Animals.
_ A piece of ancient Hindu Sculpture, representing a female (goddess), with a child, walking, dug up in the ruins of Canouj, was presented by Colonel STACY.
Literary. Read a_ letter from W. H. hlnowscnrnu, Esq., Secretary to Government, Political Department, forwarding on behalf of the Honorable the Governor General of India in Council, a copy of notes taken by Captain
Wane, relative to the territory of Iskardoh, and of his correspondence with the ruler of that country.
A memoir on the mountain tribes, on the extreme N. E. frontier of
Bengal, by J. McCosn, Civil Assistant Surgeon at Goalparahflzresented by the Author.
Extracts from both these papers were read.
_ Physical. The following extract of a private letter from Captain,C_1_lUr1.n_Y to the
Secretary was read, noticing the discovery of further fossils in vast quantity in the Sewélik range. ‘