maS^e on a M'meral called Cerite. 197 



washed, and calcined, weighed seventeen parts : it was 

 silex, still slightly coloured yellow. 



The nitro-muriatic solution being evaporated to dryness, 

 and its residuum redissolved in water, left about one part 

 of silex coloured by a little oxide of cerium. 



The same solution freed from silex, and united to the 

 washings of _ the silex, was decomposed by ammonia : the 

 oxide of cerium and the oxide of iron precipitated by these 

 means, were separated from the liquor by filtration. The 

 oxahc acid added to this liquor formed a precipitate which 

 by calcination gave two parts of lime. 



The metallic oxides, united and calcined, weighed seventy 

 parts : they had a beautiful reddish brown colour. To se- 

 parate the iron of the cerium the whole was dissolved in 

 muriatic acid : the sokuion being concentrated to evaporate 

 the excess of acid, then diluted with water and decomposed 

 by tartrite of potash, there was formed a vcrv abundant 

 white precipitate, which being washed till it contained no 

 more foreign salts, then dried, and calcined, gave sixtv- 

 seven parts of oxide of cerium. 



The water from the washing of the tartrite of the cerium, 

 bemg united and mixed with hydro-sulphuret of potash, 

 gave a precipitate which became black in the air. It was 

 oxide of iron, the weight of which after calcination was two 

 parts. 



Thus J.O0 parts of cerite subjected to analysis furnished, 

 J St, Silex - - 17 



2d, Lime - . o 



3d, Oxide of iron - 2 



4th, Oxide of cerium - fiy 



5thj Water and carbonic acid 1 '2 



100 



Though the specific gravity of cerite, the varied colours 

 assumed by the particular matter it contains, and the oxy- 

 gen disengaged during its solution in muriatic acid, afforded 

 great probabilities m regard to the metallic nature of this 

 eubstance ; yet, as it was possible that tliese properties and 

 these phasnomena might be owing to the presence of some 

 known metal, to manganese for example, 1 endeavoured 

 to discover it by all the means which ap[K-ared to me proper 

 for accomplishing that end ; but I did not find any sensible 

 traces ot it. It therefore appears to me altogether impro- 

 •babic that manganese should contribute any thins: towards 

 the properties exhibited by the mailer of cerite. ^ The case 

 N 3 \i 



