1840.] 



Hemarlis upon the Auiiferoiis Deposits of India. 



35 



yards to the surface, where powder is required for blasting the rock, 

 water wheels, steam engines, or other expensive machinery for draining 

 off the water, and where the price of labour is six, eight, or even ten 

 times as great as it is in India. It is true that in these mines richer ores 

 are also found, but they are in comparatively small proportion, fluctuat- 

 ing in their quantity and quality, and not to be depended on for profit- 

 able returns. 



The value of gold being fifteen tiraes greater than that of silver, it 

 will readily be conceived that very minute quantities of this preci(nis 

 metal will pay for the expenses of extraction. In point of fact the 

 poverty of some auriferous deposits is almost inconceivable, indeed it 

 often happens that the particles of the precious metal are so very 

 minute, and so sparingly scattered through the mass, that the naked 

 eye is totally unable to detect them, and except by the careful mineralo- 

 gist, the whole would be looked upon as mere worthless matter, and 

 entirely rejected. Of this general poverty of gold ores, I shall now 

 adduce a few striking examples, taken it will be observed from widely 

 distant localities. 



At Zelle in the Tyrol, a mineral district, situated a few leagues from 

 Inspruck, the gold ores, or rather the auriferous mass extracted from 

 the mines, yields on an average from five to seven ounces of the pre- 

 cious metal in 1,000 cwts. Mow this amounts to only one pound of 

 gold, in from two to three hundred thousand pounds of refuse, yet 

 even from this exceedingly poor ore, the skill of the German mining 

 Engineers, enables them^ to extract a small profit. The ore, I may 

 further observe, is a hard quartz, very similar to that which occurs north 

 of the Pennar Kiver, in the Nellore district, and requires to be stamped 

 or finely pulverized, before the gold can be extracted. At the mines 

 of Krcmnitz in Hungary, the average produce of the gold ores is only 

 7 to 8 ounces in the 1000 cwts, or 100,000 lbs, being thus very little 

 higher than in the mines of ^elle. 



Let us now turn to Brazil, a country well known for the large supply 

 of gold which its mines annually furnish. The precious metal is here 

 found in veins and worked by mining, but a vast quantity is also dis- 

 seminated in very minute particles through the sands of certain auri- 

 ferous districts, exactly as we have it in India. I have been informed 

 by my friend Mr. Attwood, who has been resident for some years in the 

 mineral districts of that country, that a cubic foot of this sand, which 

 may be estimated as weighing about 1 cwt. is considered very profitable if 

 it yields an oitava, or about one eighth of an ounce of gold, but that sands 

 are worked which do not afford more than one-tenth of this produce. 



