april — june, 1857.] Natural History. 



161 



joulat being at Vienna, received the MS. from M. de Hammer for publication in 

 Paris. It is understood that this publication will not be much longer delayed. 



Natural History. 



A paper on the metalliferous deposits of Kumaon and Gurh- 

 wal by W. J. Henwood, late Chief Mineral Surveyor in the N. W. 

 Provinces, which was read before the R. Geological Society of 

 Cornwall has appeared in the last No. of the Edinburgh New Phi- 

 losophical Journal.* 



Mr. Henwood met with copper pyrites and purple copper ore 

 in quartzose veins occurring sparingly in the granitic and gneiss 

 formation and somewhat more plentifully at the junction of the talc 

 and clay slates of Poker, Seera, &c. 



Iron ores occur in great abundance throughout the clay slate 

 formation and in some parts of the talc slate series. Mr. Henwood 

 particularly notices the fact that bunches of ore dip from the mass 

 of the nearest granite formation not only in the case of the iron of 

 the Himalayas but as regards the gold of Brazil. 



The talc slate formation he found to exhibit a strong resemblance 

 to the gold districts of Brazil particularly to the Jacotinga forma- 

 tion in which the richest gold deposits occur. Accordingly he 

 found that gold mines were actually worked in Kumaon and Gurh- 

 wal, but in the rudest and most inefficient manner. The usual 

 method of preparing the rock for being worked was to soften it by 

 the application of fire. 



" f But in their small and ill- ventilated mines this mode is very ineffective, 

 while the smoke and foul air, generated by the combustion, stop the work of 

 every other person in the mine at the time. The imperfection of the tools 

 and mode of working ; the ignorance which prevails of the advantages of 

 ventilation ; of the economy of labour, by extracting the ore through passages 

 large enough to allow ihe workmen unimpeded action ; as well as the native 

 smelter's inability to treat any but the richest and most fusible ores : render it, 

 therefore, an object of paramount importance, in the view of the Indian miner, 

 to avoid, by every possible device, the opening of large galleries. But the softer 

 and more fusible ores are far less plentiful than those which are too refractory for 

 the native smelting furnace ; and the two varieties of ore are so intimately mixed in 



* No. I. Vol. III. new series— 1856. 

 f Do. do. p. 139. 



