282 Proceedings oj the Asiatic Society. [Sept. 



culty, having slightly attacked the platinum. By this ignition, it 

 increased nearly 2 per cent, in weight. Ignited in a small glass 

 tube by the blow-pipe till the glass softened, it did not appear to 

 yield any arsenic. 



In the analysis of this sample, the arsenic (with a little antimony) 

 was separated from the other metals by fusing with Nitrate of 

 Potash, and Carbonate of Soda (Potassium Nitrate and Sodium 

 Carbonate,) or by passing Chlorine into the mineral mixed with 

 solution of Potash. As in this case, however, the action was very slow, 

 the mineral was first oxidised by a little nitric acid, then mixed with 

 solution of Potash in excess and Chlorine passed through it. This 

 plan answered very well. The results of two analysis for the three 

 principal constituents, agreeing very well, were as follows : — 



Copper, 13-28 



Iron, 43*88 



Arsenic, 37*03 



A complete analysis was made by digesting a portion for about 

 twelve hours with diluted Hydrochloric acid and thus removing 

 the oxidized matters. The results were as follows. 

 Soluble in Hydrochloric acid, dilute. 



Oxide of Copper, 1.21 



Protoxide of Iron, 1 .97 



Oxide of Lead, 1.89 



Arsenious Acid .,,.,« , 1.12 



6.19 



Insoluble. 



Copper, 12.13 



Iron, 42.12 



Arsenic, 38.45 



Antimony, .54 



Earthy Matters, 12 



93.36 



99.55 

 Loss, .45 



100. 



