M. Arfvvedson's Examination of certain Minerals. 357 



FS-f 8 AS-l-8 CS. Klaproth's analysis of the Ceylon cinna- 

 mon-stone yielded, 



Silica, 38,80 



Alumina 21,20 



Lime 31,25 



Oxide of iron . ... 6,50 

 Loss 2,25 



This result indeed does not differ considerably from my 

 own ; but with regard to the smallest constituent part, viz. the 

 oxide of iron, it gives an essentially different formula ; for it 

 becomes FS + 4 CS + 5 AS. It may be apprehended, that Klap- 

 roth obtained too little, as well of the lime as of the alumina, 

 because he separated the first by carbonate of soda, and the 

 latter, from its solution in potassa, by muriate of ammonia. 

 His formula may therefore be considerably faulty in this re- 

 spect. I think there is reason to consider, from my analysis, 

 that this fossil from Malsjo is a real cinnamon-stone; until, 

 at least, Klaproth's analysis be i-epeated and its accuracy con- 

 firmed. 



Brazilian Chrysoberyl. 



Our knowledge of the component parts of tliis minei'al is 

 derived from Klaproth's analysis, according to which 100 parts 

 are stated to contain, 



Alumina 71,50 



Lime 6,00 



Oxide of iron ... 1,50 

 Silica 18,00 



From a series of trials before the blowpipe, to which Profes- 

 sor Berzelius has subjected most mineral productions, he sup- 

 poses that this fossil cannot essentially contaui lime, but that, 

 according to all circumstances, chrysoberyl is a pure bisilicate 

 of alumina. I am enabled to confirm this supposition by the 

 analytical examination which I here communicate. 



Analysis. 

 0,214 gram, reduced to a fine powder in an agate mortar, 

 and afterwards levigated, were mixed with a sufficient quantity 

 of caustic potassa, and exposed to a red-heat in a silver cruci- 

 ble. By an hour's continued heat, I found the mass but half 

 fused. It was then extracted from the crucible by water, and 

 treated in the usual manner with muriatic acid, which left 

 0,238 gram, imdissolved. This residue was again exposed to 

 a red-heat with potassa, and dissolved in muriatic acid : the 

 undissolved portion now weighed 0,137. After once more re- 

 locating 



