582 Ajmir Copper Mines. [Oct. 



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 Singhana mines, and the mode of extract- 

 ing and working up the ore, (by Captain Boileau, of the Engineers ?) 

 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 pro- 

 duced from these mines is, however, not thoroughly refined ; but 

 according to Captain Boileau, is brittle, and of a lilac colour : while 

 that of Basdivar in the Bhartpur 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 Shekdwaii mines have been worked in for- 

 mer 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 kos, 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 Shekuwati minerals 

 from Mr, Dean. 



Ajmir Copper Mines. 

 A new locality of copper ore has recently been brought to notice 

 by Captain C. J. Dixon, in the neighbourhood of Ajmir, where three 

 different shafts have been opened. Specimens of the ore extracted 

 thence were forwarded to me by the present Governor General, along 

 with a copv of the report from Captain Dixon, on the subject, dated 

 8th May, 1835, from which I extract the following particulars : 



