644 CERIUM. 



the alkalies, alkaline earths and other metallic oxides. It is 

 soluble in alkaline carbonates, particularly the bicarbonates, 

 and the solution deposits, after a time, lemon yellow crystals of a 

 double carbonate. The alkaline and earthy uranates assume, 

 when ignited, a deep and very beautiful orange colour, which is 

 most intense in the compounds with excess of base. This oxide 

 is employed to colour glass of a delicate lemon-yellow tint. 



Sesqui-chloride of uranium, U 2 C1 3 , is very soluble in water, 

 alcohol and ether. It forms a double salt of remarkable beauty 

 with chloride of potassium, which crystallizes from a syrupy 

 solution, 3KC1 + U 2 C1 3 + 6HO. 



The uranic sulphate combines with sulphate of potash in 

 three different proportions, forming the salts : 



2(KO, SO 3 )+U 2 O 3 , 3SO 3 

 3(KO, SO 3 ) + U 2 O 3 , 3SO 3 + 3HO 

 3KO, 4SO 3 + U 2 O 3 , 3SO 3 + 6HO. 



The proportion of the sulphuric acid and potash in the last 

 salt is very extraordinary, but is the result of exact experiments, 

 (Berzelius). The formula, however, is not to be supposed to 

 express the proximate constitution of the salt. 



The uranic nitrate is obtained by a slow evaporation in large 

 tables, which like the other salts of this oxide are of a yellow 

 colour. The nitrate is highly soluble both in water and alcohol. 

 Uranic oxide is also said to form an acid salt with nitric acid, 

 which is less soluble and more easily crystallized than the 

 neutral salt. 



The mineral uranite is a double phosphate of lime and ura- 

 nium, of which the formula is 3Ca O, PO 5 -f-2(U 2 O 3 , PO 5 ) + 

 24HO. 



CERIUM. 



Eg. 574.7 or 46.05; Ce. 



This metal was named Cerium by Hisinger and Berzelius, 

 from Ceres. Although not an abundant element, it is found in 

 a considerable number of minerals all from Sweden and Green- 

 land. The mineral cerite is a cerous silicate, containing 68.6 

 per cent of cerous oxide, with small quantities of lime and 

 peroxide of iron. This mineral is boiled in aqua regia, by 

 which the silica is separated, and the other oxides dissolved. 

 The iron is precipitated by benzoate of ammonia, and then 



