72 



L. F. Nilson, 



4 VSelenite: Hg 8 .0 7 .3SeO + f,H 2 = 3(Hg 2 .0 2 .SeO) +Hg 2 0-1-6H 2 0. 



This salt was formed, when 6 /v -selenite was digested with 8 mol. 

 or 24.1 pr. ct. selenious anhydride, and proved, when viewed with the mi- 

 croscope, to be crystallized and composed of small, fine prisms. 



Analyses: 



1) 0.5015 gr. salt, dissolved in hydrochloric acid, immediately gave 0.0315 

 gr. selenium or 0.0443 gr. selenious acid, and in the filtrate from it 

 0.444 gr- mercuric sulphide = 0.3981 gr. mercurous oxide and 0.022 

 gr. selenium or 0.0309 gr. selenious acid. 



2) 0.44 ( j gr. salt, treated with hydrochloric acid, gave an undissolved re- 

 sidue of 0.0295 gr. gr. selenium or 0.0415 gr. selenious acid; from the 

 filtrate there was obtained, by precipitating with hydrosulphuric acid, 

 digesting with cyanide of potassium and precipitating the solution with 

 hydrochloric acid, 0.396 gr. mercuric sulphide = 0.355 gr. mercurous 

 oxide and 0.019 gr- selenium or 0.0267 gr. selenious acid. 



Calculated on 100 parts: 



experiment theory 



1.2. 



Mercurous oxide . . . < 79.38 79.09 4Hg 2 1664 79.05 



Selenious acid .... 14.99 15.19 3Se0 2 333 15.82 



Water (loss) _ 5.63 5.72 6H 2 108 5.13 



100.00 100.00 2105 100.00 



The relation of the quantity of selenium, immediately precipitated 

 by muriatic acid, to the dissolved quantity is as 1.5 to 1, the formula: 



Hg 8 . 7 .3SeO + 1 6HC1 = 8HgCl 2 + 2Se + SeO 2 -f- 8H 2 

 requiring 2 to 1, a difference, not easily accounted for. 



5. 9 / 5 -Selenite: 5Hg 2 .0 2 .SeO +-4H 2 .0 2 .SeO + 8H 2 0. 



When 6 / 7 -selenite was digested with 22 mol. or 66.26 pr. ct. sele- 

 nious anhydride, this salt was obtained as a yellowish powder, which, un- 

 der the microscope, proved to be coarsely crystalline. 



