98 



L. F. Nilson, 



Cleve l ) obtained the same salt by mixing chloride of lanthanum 

 with selenious acid and alcohol. 



SELENITES OF DIDYMIUM. 

 l. %-Selenite: Di B .O l7 .8SeO + 28H 2 0. 



On mixing- sulphate of didymium with an excess of selenite of so- 

 dium, an amorphous, white precipitate, slightly inclining to rose, was 

 thrown down. 



Analyses: 



1) 0.5083 gr. salt, gave 0.1356 gr. selenium or 0.1905 gr. selenious acid 

 and 0.3627 gr. sulphate of didymium, containing 0.2131 gr. oxide of 

 didymium. 



2) 0.5153 gr. salt gave 0.139 gr. selenium or 0.1953 gr. selenious acid 

 and 0.3697 gr. sulphate of didymium, containing 0.2172 gr. oxide of 

 didymium. 



Centesimally represented: 



found calculated 



1. 2. 



Oxide of didymium . 41.92 42.15 3Di 2 O 3 1026 42.43 



Selenious acid .... 37.48 37.90 8Se0 2 888 36.72 



Water (loss) JKUO _12^b 28H 2 _504 20.85 



100.00 100.00 2418 100.00 



Sulphate of didymium with selenite of sodium gives consequently a 

 basic salt, analogous in composition to selenites of iron and lanthanum, 

 treated of above. 



2. */» -Selenite: Di 2 G .3SeO-fH 2 .0 2 .SeO + 8H 2 0. 



Was obtained in the same way as the corresponding selenite of 

 lanthanum, and formed a microscopically crystalline powder of four-sided 

 prisms. 



') Bib. t. Sv. Vet. Akad:s handl. II N:o 7 s. 45. 



