48 



Chemical Analysis of certain Minerals. 



rupees per annurn. The usual hire of a labourer on the spot is, I be- 

 lieve, 4 pice and a meal of rice per diem. The opening of a new mine 

 in the dry season presents an animated scene, and was sometimes 

 honoured by the presence of the Kurnool Nabobs. 



Diamond mines formerly were worked in the Kurnool territory, at 

 Saitancota, Deonoor, and Tandrapaud. They are cut and polished by 

 the jewellers of Muni Mudgoo, who have been long famous for their 

 skill in polishing diamonds, and were formerly sent for sale to the 

 metropolis of Golconda, and subsequent to its full, to that of Hydra- 

 bad. 



I have the pleasure to present to the Society a model of a dia- 

 mond polishing machine, used at Muni Mudgoo, and constructed for 

 me there by one of the polishers. The use of diamond dust in the 

 process of polishing is thoroughly understood by the natives, and in 

 splitting the larger gems they take advantage of the planes of cleavage. 



Examination of the specimens of Minerals alluded to in the foregoing 

 paper. — By Lieutenant J. Braddock. 



No. 1. — Gold dust, found in Hack mngnetic sand.—Uhe grains of 

 gold, though few, being large enough to form a judgment on, need not 

 to have been tested ; bur, on testing them, after solution in nitro-mu- 

 riatic acid, no doubt existed of their being gold. 



N *. 2. M nochanite ? — Feebly magnetic ; in small grains, somewhat 

 like corirse gunpowder. External appearance agrees to the description 

 given of menachauite in lire's Chemical Dictionary. It was examined 

 as follows. 



Blow-pipe. — With borax on charcoal, fused into a green glass. -Fused 

 with j)ure potash on platina foil, and treated with muriatic acid at a 

 boiling heat, the powdered substance was partly soluble, leaving a dark 

 brown residue. The muriatic solution was milky yellow, which, when 

 tested, gave the following indications : — 

 Tincture of galls — Reddish brown colour. 



Oxalic acid— 'No immediate effect : next day a small whitish precipitate. 

 Jmm,onia — Copious dirty brown precipitate : next day clear reddish 



brown solution, with darker precipitate. 

 Uydrosulphvret of Ammonia — An immediate deep greenish black, 



changing almost instantly on the surface to white, and passing 



afterwards into a dirty yellowish brown, which was ultimately 



precipitated. 



