Researches on the Salts of Selenious Acid. 



51 



6. Triselenite: Be.0 2 .SeO + 2H 2 .0 2 .SeO. 



2 / 5 -selenite being treated with 378.45 pr. ct. of its own weight of 

 selenious anhydride, the solution, that consequently contained 1 mol. of 

 glucina to 4 mol. of selenious acid, on slowly evaporation at 60° in the 

 above-mentioned manner, afforded a salt in flat, four-sided, oblong, micro- 

 scopic prisms with basal end-faces and often two opposed angles truncated. 

 Permanent on exposure to the air, the salt was with the utmost difficulty 

 soluble in water, warm as cold, and, not before boiling, easily dissolved in 

 dilute hydrochloric acid. 



Analyses: 



1) 0.6727 gr. salt gave 0.3985 gr. selenium or 0.56 gr. selenious acid and 

 0.0468 gr- glucina. 



2) 0.7473 gr. salt gave 0.444 gr. selenium or 0.6238 gr. selenious acid 

 and 0.0523 gr. glucina. 



Calculated on 100 parts: 



found calculated 



1. 2. 



Glucina 6.96 6.99 BeO 25.2 6.39 



Selenious acid . . 83.25 83.48 3Se0 2 333.0 84.48 



Water (loss). . . . 9^79 2H 2 36.Q 9.13 



100.00 100.00 394.2 lOOToo 



Any salt, more acid than this, of the metal in question, seems con- 

 sequently not possible to be formed. 



If we recollect from the preceding that magnesium, under similar 

 circumstances, also gives a triselenite of an analogous composition: 



Mg.0 2 .SeO-(-2H 2 .0 2 .SeO 



and anticipate from the following that cobalt has in the same manner 

 given a salt: 



Co.OlSeO + H 2 .0 2 .SeO + SeO 2 



and that all the metals, forming basic sesquioxides with oxygen, have not 

 given more acid salts than diselenites with excess of selenious acid, and 

 for the rest behave in a different manner, it seems to me, that this cir- 

 cumstance may be added to the reasons previously known, for considering 

 glucina as a monoxide. 



