g^^ ACCOUNT OF CERIUM. 



out any flux, and M. Hjelm expofed it for half an hour to 

 the degree of fire neceflary for the redu6lion of manganefe. 

 The oxide was not melted, but reduced into a very fine pow^ 

 der : it exhibited brilliant particles in the daylight, and 

 ftained white paper black. It difiblved in muriatic acid, dif- 

 engaging, at the firft, fulphurated hidrogen gas, and after- 

 wards pure hidrogen gas. This colourlefs folution had a fac- 

 charine tafte. Thus it appeared to us that the metal was re« 

 duced in part. The origin of the fulphur may be traced to 

 the fulphuric acid, from which the matter had been feparated 

 by the cauftic ammonia. The influence which this acid ex- 

 ercifes in thefe aflays, will be feen by the fubfequent en- 

 quiries. 



M. Gahn, at Fahlun, having more convenient furnaces, 



has promifed to undertake the reduftion of this fubftance with 



more power: if this operation fucceed, we fliall give an ac-. 



count of it hereafter. 



It is the oxide Thefe appearances, and thofe which follow, determined 



pfa metal not yj (q confider the fubftance found in the cerite, as the oxide 



^ ' of a metal hitherto unknown, to which we have given the; 



name of Cerium, from the planet Ceres, difcovered by Piazzi. 



Manner of obtaining the pure Oxide of Cerium. 



ProcefTesfor ob- T-^O Pure uncalcined cerite was diflblved innitro-muriatic, 



taining the pure and, after faturating the clear folution with the alkali, was 



precipitated by tartrite of potafli. The precipitate well 



wathed, calcined, and digefted in vinegar, contains the pure 



oxide of cerium. 



Or otherwife decompofe a folution of cerium in nitro-mu- 

 riatic acid, ftill warm, but not faturated, by fuccinate of am- 

 monia : a fuccinate of iron is gradually depofited. The pre- 

 cipitation is to be continued by means of fuccinate of ammonia, 

 as long as a red precipitate is formed : the folution is then 

 nearly deprived of iron. After having feparated the fuccinate 

 ©f iron, more fuccinate of ammonia is poured into it, until a 

 ■white precipitate appears. The folution is then left at reft, 

 in order that the fraall portion of fuccinate of cerium may be 

 depofited. The iron diflblved by the free muriatic acid, is 

 depofited at the fame time, and the folution is freed from this 

 metal. The cerium may afterwards be precipitated by am*^ 

 XPOni^i, and then waflied and calcined* 



