Samarium. 33 



Cale 



Sm^Oj 25.62 23.43 



NajO 6.10 6.26 



WO3 68.16 70.31 



The salt contained as impurity a little of oxide of samarium. 



Metatungstate of samarium 



Sm,03,12W03 + 35H20. 



Metatungstate of barium was decomposed with a calculated quan- 

 tity of sulphate of samarium and the solution evaporated over oil of 

 vitriol. From the very concentrated solution large, topas-yellow and well 

 formed crystals were obtained. They salt is easily soluble, but not de- 

 liquescent. It becomes opaque when exposed to light. It loses at 100" 

 12.21 percent HgO or 25 mol. H2O (cale 11.96). 



I. 1.4985 gram salt, pressed between filter-paper, lost, on heating 

 nearly to redness, 0.2510 gram H2O and gave on decomposition with 

 concentrated sulphuric acid 1.0995 gram WOg. From the filtrate from 

 the tungstic acid 0.1394 gram SmgOg was precipitated as oxalate. 



II. 1.1556 gram lost on heating 0.1951 gram HjO and gave, when 

 decomposed with hydrochloric acid, 0.8504 gram WO3 and O.1O88 gram 

 SmgOg precipitated as oxalate. 



Spec. Grav: 



2.5007 gram, large crushed crystals, temp. 18°.2 sp. Gr. 3.996 

 2.3130 » » » » » 18''.4 » » 3.992 



Mean of both determinations: 3.994. 

 Molecular volume: 941.9. 



Nova Acta Eeg. See. So. Ups. Ser. III. i 



