430 Mr. Seyberfs Analyses of the [June, 



and sulphuric acid it gave regular octohedral crystals of alum. 

 The liquor, when tested with phosphate of soda and ammonia, 

 was found to contain ho magnesia. 



After the preliminary experiments, I commenced the following 



Analysis of the Chrysoberyl from Haddam. 



A. Five grammes of the mineral, reduced to small fragments 

 in an iron mortar, were carefully porphyrised in one of agate, 

 from which it acquired the additional weight of 0*13 grammes. 

 The 5*13 grammes were then exposed to a red heat, and thereby 

 suffered a diminution of 0*40 per 100. 



B. The calcined mineral (A) was heated, during one hour, in 

 the silver crucible, with caustic potash, and the product was 

 treated with diluted muriatic acid ; the solution was of a letnon- 

 yellow colour. There remained a white insoluble residue, 

 which after calcination weighed 1*47 grammes. It was repeat- 

 edly calcined with caustic potash, and treated with diluted 

 muriatic acid, with the following results : 



After the 2d experiment, it weighed 0-97 grammes. 

 3d 0-89 



4th 0-85 



By the fifth treatment it was not diminished, and then pre- 

 sented itself in the form of a light white powder, resembling 

 pure silica in appearance. 



C. The residue (B) was repeatedly strongly calcined with six 

 parts of nitrate of barytes, and subsequently boiled with nitric 

 acid. 



* After the 1st treatment, there remained 0-43 grammes. 



2d 0-15 



3d 006 



And by the 4th operation only 0-01 gramme was dissolved. 



The remaining 0*05 gramme was essayed in the manner 

 related in the preliminary experiments, and thus proved to be 

 oxide of titanium. , Hence we have 1 per 100 of that oxide. 



D. The nitric solutions were united and evaporated to dry- 

 ness to expel the excess of the acid. The saline mass was 

 dissolved in water, and after the barytes was separated with 

 sulphuric acid, an excess of subcarbonate of ammonia was 

 added to the solution. An abundant precipitate appeared, 

 which entirely redissolved. The glucina was precipitated by 

 ebullition. After edulcoration and calcination, it weighed 0*79 

 gramme, or 15 - 80 per 100. 



E. The several muriatic solutions (B) were united and evapo- 

 rated to a dry mass, which was treated with muriatic acid, and 

 there remained - 33 gramme of silica, from which deduct 0*13 

 gramme acquired from the agate mortar ; and there will be 0*20 

 gramme, or 4 per 100 as a constituent of the mineral. 





