ACCOUNT OF CERIUM. ' 293 



To obtain the pure metallic matter in a fufficient quantity 

 U> make feveral affays, another portion of cerite was diffolved 

 in nitric acid, and the folution evaporated to ficcity. Water 

 was poured on the relidue, and it was precipitated with am- 

 monia. The waflied precipitate was diflblved in nitric acid. 

 The (blution, well neutralized with the alkali, was afterwards 

 precipitated by tartrite of potafli. A white powder was alfo 

 precipitated from the fame folution by carbonate of potafh, 

 but it was in fmall quantity. Thefe precipitates were fepa- 

 rately calcined, and both of them acquired the colour of bricks. 

 The precipitate formed by the carbonate of potafli, was not 

 diflblved by potafli aided by digeftion ; it therefore did not 

 contain alumine. The iron contained in the folution, preci- 

 pitated with tartrite of potafli., was feparated by hidro-fulphu- 

 ret of ammonia. The remainder of the folution of cerite in 

 nitric acid, which had been precipitated by cauftic ammonia, 

 gave carbonate of lime by carbonate of ammonia. 



From thefe aflays it refults, that cerite contains nearly 23 Component 

 parts of filex, 5.5 of carbonate of lime, 22 of oxide of iron, P^"^ of the ore, 

 and a quantity or this metallic matter, the weiglit or wliicn, o^ide of cerium. 

 after calcination, rather exceeded 50 per cent. But this fub- 

 ftance being then, as well as the iron, united with more oxi- 

 gen than they contained in the cerite, we have, inftead of a 

 lofs, an augmentation of weight, which probably arifes from 

 the oxigen. Neither is the lofs which the cerite experienced 

 in the calcination, included in this account. We alfo found 

 traces of manganefe, but in fo fmall a quantity, that potafli, 

 melted with the cerite and diflblved in water, did not give 

 any colour. 



Not having the pradice which complete proportionate ana- 

 lyfes require, we oflfer thefe refultij with diffidence, and in the 

 hope that fcientific men of more experience will employ them- 

 felves on this fubje6^. 



§ III. 



Examination of the Metallic Oxide found in the Cerite, 



A PASTE was made of 37 grains of this oxide and linfeed Examination «f 

 oil, which was reduced in charcoal in a covered crucible. ^h« oxide. 

 Although it retained fome carbon, it loft half a grain of its 

 weight. This mafs was inclofed in a lined crucible with- 

 out 



