Samarium. 23 



The ratio between Sni.Os, SeO., and H.O is 1 : 2.6 : 2.3 or 3 : 8 : 7. 



The precipitate consisted of a basic salt the composition of which, 

 if it be regarded as a chemical compound, may be expressed by the 

 formula : 



3Sm,0,,8SeO., +7H,0. 



Sm,03 , . 1044 50.73 



SeOg 888 43.15 



H^O ....... . 126 6.12 



2058 10(XÖÖ 



It seems most probable that it is only a mixture of basic salts 

 with the neutral selenite. According to M. Nilson the selenite of didy- 

 mium, prepared in the same way as this salt, has the composition 

 3Di,03,8SeO + 28H20. 



2. Acid selenite. SmgOg, 4Se0.2+5HjO. This compound was 

 thrown down, by addition of selenious acid to the solution of the ace- 

 tate, as a bulky precipitate, which was very soon transformed into 

 microscopic needles. 



0.8312 gram lost at 110" 0.0523 gram HjO, and gave, treated in 

 the same manner as the salt last described, 0.2935 gram Se, and 0.3233 

 gram SnijOg. 



0.8910 gram gave 0.0560 gram H,0, 0.3175 gram Se, and 0.3465 

 gram SmjOa. 



In percent: 



C ale 



SnijOg 38.90 38.89 348 39.46 



SeO, 49.61 50.07 444 50.34 



un a a 3H^0 54 6.12 



H^^ 6-29 6-28 2H,0 36 - 



Carbonate of samarium 



Sm,3C03+3H20 (or 2HjO dried at 100"). 



The gelatinous precipitate which the nitrate of samarium gives 

 with ammonia liquor was, after washing with cold water, suspended in 

 water and treated with carbonic-acid gaz. After some time a whitish 

 powder consisting of aggregates of microscopic needles, insoluble in 



