116 Seybert^s Analysis of various Minerals. 



B. The residue of the calcination (A,) was treated with 

 caustic potash, as in the preceding analysis, it was then 

 greenish yellow, and the water, which was used to detach 

 it from the crucible, assumed a light green colour, hence a 

 trace of Manganese. By the usual treatment, with an ex- 

 cess of muriatic acid and the subsequent evaporation of the 

 liquor, he, the Silica obtained weighed 1.51 grammes on 

 3 grammes, or 53.333 per 100. 



C. After the excess of acid, of the liquor (B) was neu- 

 tralized with ammonia, it was treated with the hydro-sul- 

 phate of ammonia, the black precipitate thus produced, af- 

 ter ignition and calcination with nitric acid, yielded 0.70 

 grammes of a residue, which, on being repeatedly treated 

 with caustic potash, was found to consist of 0.664 grammes 

 of Peroxide of Iron (but owing to the green colour of the 

 mineral, the Iron must be estimated as a protoxide,) and 

 the 0.664 grammes of peroxide an equivalent to 0.612 

 grammes of Protoxide on 3 grammes, or 20.40 per 100; 

 and Alumina 0.046 grammes, on 3 grammes, or 1.533 per 

 100. 



D. The lime obtained by the calcination of the calcare- 

 ous oxalate, which was produced by the addition of oxalate of 

 potash to the liquor, (C) amounted to 0.58 grammes on 3 

 grammes, or 19.333 per 100. 



E. The Magnesia was precipitated in the liquor, (D) by 

 Phosphate of Soda and Ammonia, the ammoniacal Phosphate 

 of Magnesia thus formed, after being calcined, gave 0.56 

 grammes of phosphate of Magnesia, equivalent to 0.205 

 grammes of Magnesia on 3 grs. or, 6. 833 per 100. 



Therefore the constituents of this mineral are, 

 per 100 parts, 



A. Water, - - 0.666, containing oxygen, 



B, Sihca, - - - 50.3,3, - - - 25.31 



B. Protoxide of Manganese, a trace - _ - 



C. Protoxide of Iron,' - 20.400, - - - 04.64 



C. Alumina, - - 01.533, - - - 



D. Lime, - - - 19.333, - - - 05.43 



E. Magnesia, - 06.833, - - - 02.64 



99.098 

 100 000 



000.902 Loss. 



