CERITE. 163 



and a large excess of boiling hot water containing 

 some nitric acid is poured over it, which precipitates 

 alone the basic nitrate of the oxide of cerium, which 

 is washed by decantation with hot water mixed with 

 nitric acid, as it is quite soluble in pure water. The 

 mother liquor and wash water are concentrated to a 

 syrup and again treated in the same manner. 



This last mother liquor usually contains only lan- 

 thanum, didymium and magnesia, and is generally 

 colored violet, which color is destroyed by alcohol and 

 other reducing agents. After concentration, crystals 

 of double salts of these bases are formed. 



The metal cerium was obtained by the following 

 process: a solution of the brown oxide of cerium in 

 hydrochloric acid was mixed with an equivalent quan- 

 tity of chloride of potassium and of chloride of ammo- 

 nium, and the whole evaporated to dry ness. The mass 

 was then transferred to a platinum crucible, and heated 

 until the whole of the chloride of ammonium was 

 volatilized and fusion obtained. The fused mass was 

 poured out, coarsely powdered, and mixed, while still 

 warm, with fragments of sodium, and introduced into 

 an earthen crucible previously heated to redness. 

 When the contents had again fused, and the excess of 

 sodium volatilized, the crucible was removed from the 

 fire; the deep gray resulting mass was filled with little 

 metallic globules. In a second experiment a large 

 piece of sodium was thrown into a red-hot crucible 

 containing chloride of potassium, and then the coarsely 

 powdered chloride used as before. In operating in this 

 way. a larger proportion of metallic globules was ob- 

 tained, some of which weighed from 50 to 60 mille- 

 grams. These metallic globules appear to consist 

 principally of cerium. The color of the metal is inter- 

 mediate between the color of iron and that of lead. 

 The metal is lustrous when polished, and malleable. 

 Its density is about 5.5 at 12. Exposed to the air it 



