IgS CHRYSOBERYLS FROM 



cipltate, and was boiled, but no Glucina was precipitated from 

 it. The matter precipitated by the subcarbonate of ammonia 

 consisted of 3.68 grammes of alumina, or 73.60 per lOO., 

 and 0.19 grammes of peroxide of iron, which, on account 

 of the colour of the mineral, must be estimated as protox- 

 ide. The 0.19 grammes of peroxide are equivalent to 

 0.169 of protoxide, or 3.38 per 100. 



THE CONSTITUENTS OF THIS CHRYSOBERYL THEREFORE 



ARE, 



(Per 100 parts) 



Loss 1.82 



As the preceding results differed so essentially from the 

 analyses of the chrysoberyl from Brazil by Klaproth and 

 Arfwedson, I determined to examine a specimen from that 

 locality. 1.5 grammes were analysed in the manner above 

 mentioned, and the following results were obtained : — 



