\ 



342 Seybert^s Analysis of the JSIadureiie. 



in his analysis of the Pyrophysalite, Pycnitc and other 



Topazes 



- Analysis, 



A. Three gramaies of the pure mineral, finely pulver- 

 ized and subject'^d to the action of a red heat, underwent 

 no material alteratiun, except a diminution of 0.03 gr. oa 

 3 grammes, hence we have 1 per, 100 of water, 



B. The calcined mineral (A), was exposed to a red heat,^ 

 during one hour in a platina crucible, with 18 grammes ot 

 crystallized sub-carbonate of soda, the mixture did not 

 fuse, when cold its colour was yellowish brown, it was 

 treated with water and the solution was filtered, the filtered 

 liquor w^as treated with an excess of acetic acid, when 

 treated with carbonate of ammonia it gave no precipitate; 

 it therefore contained no silica: it was again supersaturated 

 with acetic acid and boiled to expel the carbonic acid, the 

 excess of acetic acid was then neutralized with ammonia, 

 and the hquor was treated with muriate of Lime, whlch^ 

 occasioned a white, flaky precipitate, possessing the proper- 

 lies of filiate of lime; when calcined, it weighed 0.44 

 grammes: this result was verified by a second experiment, 

 in which! obtained 0.43 grammes of fluate of lime, and 

 on calcining the mineral a second time, with sub-carbonate 

 of soda, I asccrtaint'd that the fluoric acid had been com- 

 pletely separated, the 0.44 grammes of fluate of lime are 

 equivalent to 0.1225S grammes of fluoric acid on 3 gram- 

 mes, or 4.036 per 100. 



C. The residue, on the filter (B), was Treated with mu- 

 riatic acid, wt;ich converted it into a jelly; it was evaporated 

 t.> dryness, then treated with w^ater acidulated with muriatic 

 add, and again moderatly evaporated, more water was 

 added and the solution was filtered, the silica, remaining 

 on the filter, after edulcoration and calcination, weighed 

 0.98 grammes on 3 grammes, or 32. ^^66 per 100. A sec- 

 ond expriment yielded precisely the same quantity ot 

 silica. 



p. The iron was separated from the liquor (C), as ia 

 the 1st Analysis; the per-oxide thus obtained, w^eighed 

 O.OT grammes on 3 gr. or 2.333 per 100. 



