584 Ajmir Copper Mines. [Oct. 



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 

 large 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 Dixon 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 Ajmir 

 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 of carbonate on a ferruginous matrix, 

 or veins in quartz and a micaceous schist. 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 Ajmir, is accom- 

 panied 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 ore ; it is of a fine blue colour, translucent 

 where thin, breaking with conchoidal fracture, and apparently capa- 

 ble of being converted to ornamental uses. It differs from the tur- 

 quoise*, in being insoluble in acids, which take up only the green 

 colouring matter, a carbonate of copper. I have not further analysed 

 this curious mineral. 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 Gtigra, four miles N. N. E. of 

 Ajmir, the malachite is associated with carbonate of lead, a micaceous 

 carbonate of iron, and with a rich galena or sulphuret of lead. Yel- 

 low copper pyrites also shews itself, and earthy veins of a pale blue, 

 very similar to some of the streaks in the turquoise rocks of Nisha- 

 pur, 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 Ajmir hills : the matrix of the turquoise is also a red iron clay ore, 

 very similar to that of the copper mines. 



* See analysis of this mineral in the Gleanings in Science, ii. 375. 



