104 



L. F. Nilson, 



When this salt with 25.66 pr. ct. selenious anhydride and water 

 was allowed to digest at a temperature of 60°, there was obtained, no 

 solution taking place, 



2. Va-Selenite: 3(U 2 2 ).0 2 .SeO + 2H 2 .0 2 .SeO+7H 2 0. 



The compound deposited as a beautifully yellow-coloured crystal- 

 powder which, under the microscope, proved to be completely homogeneous 

 and composed of rhombic tablets with the acuter summits often truncated. 



In the mother-liquor, that was slightly yellow, a small quantity of 

 uranium was met with, so that it was coloured brown by ferro-cyanide of 

 potassium; after evaporation it at last yielded colourless crystals of sele- 

 nious acid. The salt was insoluble in water, with which it was washed 

 previously to analysis. 



Analyse s: 



1) 0.5045 gr. salt gave 0.1225 gr selenium or O.1721 gr. selenious acid 

 and 0.262 gr. uranous oxide or 0.2775 gr. uranic oxide. 



2) 0.61 gr. salt gave 0.1488 gr. selenium or 0.2091 gr. selenious acid 

 and 0.32 gr. uranous oxide or 0.3389 gr. uranic oxide. 



3) 0.589 gr. salt, when dried at 100°, gave off 0.053 gr. water. 



Calculated on 100 parts: 



experiment theory 



1. 2. 3. 



Uranic oxide. . . . 55.00 55.56 — Ur 2 3 856.8 54 44 



Selenious acid .. . 34. 11 34.28 — 5Se0 2 555.0 35.27 



Water (loss) .... 10.89 10-16 8.83 9H 2 _}0_-29 



100.00 K)0. 00 1573.8 100.00 



The loss the salt suffered at 100°, amounts to 8 mol. water 

 (calc. 9.24). 



The same salt but with a different amount of water 



3. Va-Seleilite: 3(Ur 2 2 ).0 2 .SeO + 2H 2 .0 2 .SeO + 5H 2 0, 



was obtained by treating the neutral salt with 51.32 pr. ct. selenious an- 

 hydride under the same circumstances as in the case of the preceding salt. 

 It formed a microscopically crystalline powder. 



