53 EXrCRIMEKTt OK ALtANITl. 



d. The solutions o(' cerium m acids have an astringent 

 taste, with a p)€rce|ir«bfe 8weemes8> which, however, is dif- 

 Cpreot from the sw*retn<»s, which some of the solutions of 

 iron in acids possess. 



e. The muriate and sulphate of cerium readily crystal- 

 lise; but I could not succeed in obtaining crystals of lutrate 

 of cerium. 



Best m«tKod f» The best way of obtaining pure oxide of cerium i»» to 



Ae*«at^"* F^cipiUte the solution by oxalate of amuionia, wash the 



precipitate well, and expose it to a red heut. The powder 



i^tained by this piocess is always red : but it varies very 



roach in it::, shade, and in its beauty, according to circnm* 



stances. This powder always contains carbonic acid. 



Csscntal cha. g, 1 consider the following as tl^ es>rential characters of 



"^1^ certutn. The solution Jmss a sweet astringent taste. lti» 



precipitated white by prussiate of potash, oxakite of ammo* 



liia, tartrate of potash, carbonate of potash, carbonate of 



ammonia, succinate of ammonia, benzoate of potash, and 



bydrosulphuret of ammonia. The precipitates are redis- 



solved by nitric or muriatic acids. Ammonia throws it 



down in gelatinous flocks. Zinc dees not precipitate it 



at all. 



A. The white oxide of cerium, raent'ioned by Hisinger and 

 Berzelius, and described by Vauquelin, did not present 

 itself to me in any of my experiments: unless the whito 

 Hocks precipitated by ammonia from the original solution 

 fee considered as white oxide. They became brown on dry* 

 ing, and, when heated to redness, were certainly converted 

 ioto red oxide. 



As cerium, as well as iron, is precipitated by succinate 

 of ammonia, the preceding method of separating the tv<ro 

 fiom each other was not unexceptionable. Accordingly, 

 in some subsequent analyses, 1 separated the cerium by 

 means of oxalate of ammonia, before 1 precipitated the 

 ' iron. I found, that the proportions obtained by the analysis 



above described were so near accuracy, that no material 

 alteration is necessary. 

 XI9M, 8. The liquid, thus freed from iron, alumina^ and cerium, 



iqeas mixed with carbonate of soda. It precipitated a quan- 

 tUy of carbonate of lime, which amounted, as before, to 



about 



