26 



L. F. Nilson, 



Analyse s ; 



1) 0.7395 gr. salt gave 0.2525 gr. selenium or 0.3548 gr. selenious acid 

 and 0.4155 gr- sulphate of thallium or 0.3494 gr. thallious oxide. 



2) 0.598 gr. salt gave 0.2043 gr. selenium or 0.287 gr. selenious acid and 

 0.3215 gr. sulphate of thallium or 0.2705 gr. thallious oxide. 



Calculated on 100 parts: 



experiment theory 



1. 2. 



Thallious oxide . . 47.26 45.24 V 2 T1 2 212 45.99 



Selenious acid . . 47.98 48.00 2Se0 2 222 48.16 



Water (loss) . . . 4.76 6-76 iy 2 H 2 __27 5.85 



100.00 100.00 461 100.00 



When this salt, for the analysis, was treated with hydrochloric acid, 

 pink selenium was thrown down, thallious oxide being oxidated at the 

 expense of the selenious acid. A similar process takes place, when ferrous 

 and hydrargyrous selenites are dissolved in hydrochloric acid. 



SELENITES OF SODIUM. 



1. Neutral: Na 2 .0 2 .SeO + 5H 2 0. 



When a solution containing this salt, prepared quite in the same 

 manner, as the corresponding salt of potassium, by evaporation at the or- 

 dinary temperature, has assumed the consistency of syrup, it begins to afford 

 the salt, either in microscopic needles united in bundles, strongly contracted 

 in the middle, or, more rarely, in very large, four-sided prisms, with the 

 ends on both sides obliquely cut off. The crystals are persistent in contact 

 with the air and extremely soluble in water. In dry air, they part with 

 their crystallization-water. 



Analyses: 



1) 0.689 gr. salt gave 0.207 gr. selenium or 0.2909 gr. selenious acid 

 and 0.3708 gr. sulphate of sodium or 0.1619 gr. soda. 



2) 0.641 gr. salt gave 0.1915 gr. selenium or 0.269 gr. selenious acid 

 and 0.344 gr. sulphate of sodium or 0.1502 gr. soda. 



