BowerCs Analysis of the Pyroxene. 345 



C. The liquor (B) having been neutralized with am- 

 monia, was treated with the hydrosulphate of ammonia. 

 The black precipitate which was produced after being heat- 

 ed to expel the sulphur, and calcined with nitric acid, 

 weighed 4.192 grains. The aiumine separated in the usu- 

 al manner by the action of caustic potash, weighed 531 

 grains or 1.062. per 100. 



D. The metallic oxides, after the separation of the aiu- 

 mine, weighed 3.645 grains. They were treated with mu- 

 riate of ammonia to which a small quantity oi sugar had 

 been added, in order to separate the manganese. The per- 

 oxide of iron remaining, was equal to 3.004 grains of pro- 

 toxide in 50 grains, or to 6 008 grains per 100. The pro- 

 toxide of manganese amounted to .598 grains per 100. 



E. Oxalate of potash was then added to the liquor, 

 (D.) The precipitate of oxalate of lime when calcined 

 yielded 11,810 grains of lime, or 23.620 grains per 100. 



F. The magnesia was precipitated from the solution, 

 (E) by caustic potash at a boiling heat; when washed and 

 calcined, it weighed 07.250 grains or 14.500 per 100. 



The results of this analysis, give as the composition of 

 this mineral per 100 parts : — 



A. Water . . . 00.468 containing oxygen. 



B. Silica . . . 53.124 . . 26.72 



C. Aiumine . . . 01.062 . . 



D. Protoxide of Iron . 06.008 . . 01.36 



D. Protoxide of Manganese 00.598 . . 



E. Lime . . . 23 620 . . 06.63 



F. Magnesia . . . 14.500 . . 05.81 



99.380 

 100.000 



000.620 loss. 



Some mineralogists have considered this substance as 

 Diallage. The preceding experiments, however, sufficient- 

 ly prove that it is distinct from that mineral. In its exter- 

 nal characters, and also m its chemical composition, it cor- 

 responds almost exactly with the Pyroxene Sahlite of Swe- 

 den. It was discovered a number of years since by Pro- 



