466 Scientijic Intelligence, [June, 



remaining liquid not giving any precipitate by evaporation, there could 

 have been no glucina in the mineral. The powder which remnined 

 undissolved by the potash consisted of 0*4:08 per cent, magnesia, and 

 1*402 per cent, oxide of manganese, with a trace of oxide of iron. 

 These two analyses give, therefore, the following results : 



Silica 49-06 



Alumina 33*61 



Magnesia 408 



Oxide of manganese ] -402 



Oxide of iron Trace 



Fluoric acid 3*44 



Phosphoric acid 0122 



88*042 



Experiments in order to ascertain the quantity of the alkaline 

 bodies. 



Sixty parts of lepidolite, mixed with 240 of carbonate of barytes, 

 were kept red-hot for two hours. The mass was dissolved in muriatic 

 acid, the barytes thrown down by sulphuric acid, and at last sufficient 

 carbonate of ammonia was added to precipitate all the earths and 

 metallic oxides which had been dissolved. When the solution was 

 afterwards evaporated, and the salt heated, there remained 12*7 of a 

 sulphate. It still contained some oxide of manganese, and to remove 

 that, it was dissolved in water, and then mixed with hydrosulphuret of 

 ammonia. Now the alkaline sulphate still weighed 1236 parts, and 

 hy muriate of platinum, there was obtained 3*5165 potash = 6503 

 sulphate of potash, so that there remained for the sulphate of lithia 

 .5*857 parts. However, after having removed all platinum from the 

 solution, there remained 7'7 parts of pure sulphate of lithia, which Dr. 

 Gmelin considers as the correct quantity, it being difficult to free the 

 triple muriate of potash and platinum by washing, from all muriate of 

 platinum. It is, therefore, probable, that the quantity of sulphate of 

 potash is too great, and that it would only be 0*466 = 0251965 pot- 

 ash, or 4*1 866 per cent. 



Supposing 100 parts of sulphate of lithia to contain 27*99 lithia, 

 the quantity of lithia would amount to 3 592 per cent. : 100 parts lepi- 

 dolite lost in the fusion, in a violent heat, 1 947 per cent, which, besides 

 water, certainly consisted of fluoric acid and silica. The composition 

 of lepidolite is, therefore, 



Silica 49*D6 



Alumina 33*61 



Magnesia 0408 



Oxide of manganese 1*402 



Oxide of iron Trace 



Fluoric acid 3'44 



Phosphoric acid 0112 



Potash 4*186 



Lithia 3-592 



Water and loss 4190 



100*000 



