62 



L. F. Nilson, 



Calculated on 100 parts: 



found 



calculated 



Oxide of copper . . 23.90 

 Selenious acid ... 61.02 

 Water (loss) .... 15.08 



CuO 79.5 22.36 

 2Se0 2 222.0 62.45 

 3H 2 54.0 15.19 



100.00 



355.5 100.00 



3. Diselenite: Cu.0 2 .SeO. + H 2 .0 2 .SeO. 



The foregoing neutral selenite of copper was treated with 49 and 

 147 pr. ct. anhydride of selenious acid and the mixture digested at about 

 60°. The solution, having evaporated to dryness, afforded, on treatment 

 with water, a therein insoluble salt in form of blue-green, microscopical, 

 four-sided prisms with obliquely cut ends. The analyses 1) and 2) refer 

 to a material, obtained when diselenite, 3) when tetraselenite could have 

 been formed. 



Analyses: 



1) 0.5805 gr. salt gave 0.28 gr. selenium or 0.3934 gr. selenious acid and 

 0.1435 gr. oxide of copper. 



2) 0.5 gr. salt gave 0.243 gr. selenium or 0.3414 gr. selenious acid and 

 0.1232 gr. oxide of copper. 



3) 0.596 gr. salt gave 0.2925 gr. selenium or 0.411 gr. selenious acid and 

 0.1425 gr- oxide of copper. 



Consequently copper does not afford any salts, more acid than 

 diselenite. 



Represented in 100 parts: 



theory 



Oxide of copper . 24.72 24.64 23.91 

 Selenious acid . . 67.77 68.28 68.96 

 Water (loss). . . . 7.51 7. 08 7.13 



CuO 79.5 24.89 

 2SeO 222.0 69.48 

 H 2 18.0 5.63 



100.00 100.00 100.00 



319.5 100.00 



