Analyses of Chabasie. 367 



but that of Berzelius, C ^ ... 



N V Si+3A1 Si2+6H 



K ^ 



which however was rejected, as the crystals did not rest on quartz, 

 by which they might have been penetrated, for in this way Berzel- 

 ius accounts for the surplus of silica in his analysis, compared to that 

 of Arfvedson, (Edin. Phil. Journal, Vol.7, p. H.) I likewise ex- 

 amined the Chahasies from Aussig in Bohemia, and the Fassathal, 

 Tyrol. These however, I found to accord with the formula of Arf- 

 vedson. 



Having with equal minuteness, followed the same method in all 

 these three analyses, I cannot, (unless some analysis should hereaf- 

 ter correct mine,) but declare that the mineral from Parsboro', is " no 

 Chabasie," particularly as the specific gravity too, differs in a meas- 

 ure, and as this mineral is not as easily affected by muriatic acid, as 

 the others. I proceeded in the analysis in the following manner. 



After reducing the mineral to a powder, in a mortar of agate, it 

 was levigated, weighed and treated with muriatic acid ; the fluid be- 

 ing diluted with water, the silica was collected on a filter, calcined 

 and weighed, and then boiled with carbonate of soda. The portion- 

 which did not dissolve, was deducted from the quantity used. The 

 alumina was precipitated by ammonia from the fluid, freed of silica,, 

 afterwards weighed, and again dissolved by muriatic acid. This left 

 a trifling quantity of silica. 



In No. HI, the oxide of iron was separated by succinate of soda^, 

 from the dissolved alumina. The lime was precipitated by oxalate 

 of ammonia, from the solution which had been freed of alumina, the 

 fluid was evaporated to dryness, the muriate of ammonia dissipated 

 by calcining, and the weight of the chloride of soda and chloride of 

 potash, ascertained. These were hereafter again dissolved in water, 

 a solution of chloride of platinum, being^ added ; and evaporated with 

 a moderate heat. The residue was treated with alcohol, by which 

 process the soda alone was dissolved, the quantity of potash was de- 

 termined from the chloride of potash and platinum, and that of the 

 soda ascertained by the loss. The quantity of the water was deter- 

 mined, by calcining another portion of the mineral. I convinced my- 

 self, that none of the chabasies I analyzed, contained either muriatic 

 or fluoric acid. 



