New Mineral. 299 



c. The solution, remaining after precipitation by oxalic acid, 

 was evaporated to dryness, and the sal ammoniac driven off by 

 heat. The remainder washed with water left .018 grammes of 

 magnesia, slightly tinged by oxide of manganese, which was 

 in too small quantity, however, to admit of separation. 



d. The washings by evaporation gave .0205 gr. of mixed 

 chlorides of potassium and sodium. These were separated by 

 chloride of platinum — the salts after mixture with it being 

 dried, and the soda salt separated by alcohol. In this way 

 the salt was found to contain .0113 chloride of potassium, and 

 .0092 chloride of sodium, answering, the former to .007 gr. of 

 potash, and the latter to .0049 gr. of soda. 



e. The precipitate (from b) became dark by washing from 

 the presence of protoxide of manganese. It was dissolved 

 again, while still moist, in muriatic acid, and the filter carefully 

 washed. Through the solution a stream of sulphuretted 

 hydrogen gas was passed, which separated a black precipitate. 

 From this precipitate well washed, hydro- sulphuret of ammonia 

 separated a minute trace of sulphuret of tin, too small to be 

 collected or weighed. The precipitate was treated with nitric 

 acid to full oxidation — afterwards a little sulphurous acid was 

 added, and the whole evaporated by a gentle heat till the ex- 

 cess of sulphuric acid was driven off. From the dry mass 

 water separated a metallic salt, from which ammonia gave a 

 precipitate in white flakes, which weighed .005 gr., and which 

 before the blowpipe exhibited all the properties of the oxide of 

 tin, and was reduced with carbonate of soda to white malleable 

 globules. That which remained insoluble in water was sul- 

 phate of lead, and weighed .052 gr., answering to .04, or .8 

 per cent, of oxide of lead. 



/. The liquid, after precipitation by sulphuretted hydrogen, 

 was evaporated to dryness by a gentle heat. Towards the end 

 it gelatinized, and left, after solution in water, .034 of silica. 

 The solution was precipitated by caustic potash, which was 

 added in excess, and the precipitate boiled with it. The alkali 

 dissolved .003, which, at a red heat with cobalt solution, be- 

 came blue without melting, and was, therefore, alumina. 

 Neither this nor the alkaline solution contained any trace of 

 phosphoric acid. 



OCT.— dec. 1829. X 



