Samarium. 5 



Oxide of samarium 



Sm^Oa- 



It forms an almost white powder having a very slight yellowish 

 tint. It is easily soluble in acids and is not reduced bj^ ignition in a 

 current of hydrogen. It forms no higher oxide on ignition in oxygen. 

 The oxide is ver}?- hygroscopic. 



Sp. Grav.: 



1.9113 gram t." 15" sp. Gr. 8.383 



2.1432 » )) 13" » » 8.311 



Mean of the two determinations : 8.347 

 Molecular volume : 41.7. 



Hydroxide of samarium. 



It is a gelatinous, white, and bulky precipitate which absorbs 

 carbonic acid from the air, but to a less degree than the hydroxides of 

 the other cerium-metals. It dries to yellowish semi-transparent fragments. 

 It is not soluble in alkalis, but is easily soluble in acids and expels 

 ammonia from ammoniacal salts, if boiled with their solutions. 



Salts of samarium. 



The salts of samarium are of a yellow colour, though sometimes 

 almost white, their concentrated solutions are also yellow and give a 

 peculiar absorption-spectrum. The taste of the soluble salts is sweetish 

 and very astringent. 



Sulphuretted hydrogen gives no precipitate with the salts of samarium. 



Sidjihhydrate of ammonia precipitates hydroxide of samarium. 



Alkalis precipitate completely hydroxyde of samarium, insoluble in 

 excess of alkalis. 



Alkaline carbonates give gelatinous and voluminous precipitates, 

 soluble, if recently precipitated, in excess of the reagents. After some 

 time very slightly soluble double carbonates separate out. 



Sulphate of potash gives with not too dilute solutions of salts of 

 samarium a white precipitate, very slightly soluble in a saturated solution 

 of sulphate of potash; 100 parts of the saturated solution contain about 

 0.05 part Sm^Oj. The solubility is very much influenced by the pre- 

 sence of the other earths. The solubility is increased by the presence of 

 the yttria-earths. 



