ANALYSIS OF JADE. 5 07 



2. T exposed to a red heat for two hours a mixture of ]00 Heated witU 

 parts of this jade pulverised with 450 parts of potash. The ^'^^^' ^* 

 result was a deep grass green mass, not vitrified, tliat com- 

 municated the same colour to cold water, in which it was and water a f- 

 diftused. This colour soon disappeared, the solution at the ^"sed^ 

 same time letting fall a gray flocculent precipitate, which 

 afterward became brown. These defects indicated the pre- 

 sence of oxide of manganese, which for the present I left 



mixed with the other principles of the stone. 



3. The preceding liquor, as well as the undissolved part, Muriatic acid 

 was mixed with a portion of muriatic acid in excess ; but ^"'^^'^* 



this did not attack a brown or blackish flocculent residuuni, 

 which, being mixed with thtice its weight of potash, pro- 

 duced on exposure to the fire a green glass. This dissolved 

 entirely in water and muriatic acid. The muriatic solutions 

 being mixed and evaporated yielded a jellvs which being re- 

 duced to dryness, and the residuum digested in muriatic 

 acid diluted with water, 53| parts of pure silex, distinctly 

 characterized, were obtained. 



4. The muriatic solution, separated from the silex, was Ths murip.tie 



mixed with ammonia ; and a yellow precipitate formed, cou- ^"'"^'0^ pieci,- 

 • • r ■ ■ 1 1 1 • nm • • pi'ated by am- 



sistingof the metallic oxides and alumme. This precipitatej mouia. 



vi^hile still wet, was digested with potash twice in succession, 

 to dissolve the aluinine: but this solution, when supersatu- 

 rated with acid and precipitated by ammouia, threw down 

 but half a part of alumine. 



5. The metallic oxides left on the filter after such a pro- Metallic nx'des 

 cess as the preceding are seldom pure, as they retain both '"■^^^'^ ^.'i'' 



" o . . potash, & cold 



alumine and alkali. To separate these, they were mixed water affused. 

 with five times their weight of potash, and heated red hot. 

 The result was quickly diluted with cold water, and thrown 

 on a filter, which retained the oxide of iron; a green liquor, 

 bolding in solution alumine and oxide of manganese, pass- Manganese 

 ing through. The oxide of manganese, precipitated by F'^cp'tatedb^ 

 boiling' the solojion, weighed when dry half a part. The 

 solution, after this oxide was separated from it, being super- alumine by 

 saturated with acid, and precipitated by ammonia, some alu- ammonia. 

 rviine was thrown down, which when dried at a red heat 

 ■weighed one part. 

 ' The oxide of iron, being freed from the alkali, that re- Oxide of iron 



mained 



pr-cipitated. 



