Researches on the Salts of Selenious Acid. 



37 



As the anhydrous salt now mentioned crystallizes from a solution, 

 which contains the constituents in such proportion that tetraselenite of cal- 

 cium could be formed, free selenious acid remaining-, it seems as if there 

 existed no tetraselenite of this metal. 



SELENITES OF STRONTIUM. 



1. Neutral: 2Sr.0 2 .SeO + 7H 2 0. 



This salt is precipitated in form of an indistinctly crystalline powder, 

 when a solution of chloride of strontium is treated with selenite of sodium. 

 Permanent in ordinary air, it parts with its water on being kept over sul- 

 phuric acid; when heated it fuses to a hard, white, porcellaneous mass, 

 without changing, if protected from the action of reducing gases. 



Analyses: 



1) 0.4403 gr. salt, fumed with sulphuric acid, gave 0.291 gr. sulphate of 

 strontium or 0.1641 gr. strontia. 



2) 0.4867 gr. salt, treated in a similar way, gave 0.3222 gr. sulphate of 

 strontium or 0.182 gr. strontia. 



3) 0.4945 gr. salt, gently heated over free fire, parted with 0.1105 gr. wa- 

 ter; on subsequent heating in an atmosphere of oxygen, the loss of 

 weight increased to 0.1115 gr. 



4) 0.5367 gr. salt, heated in an atmosphere of oxygen parted with 0.12 

 gr. water. 



5) 0.4095 gr. salt lost over sulphuric acid 0.0925 gr. 



6) 0.5175 gr. salt, dissolved in a small quantity of hydrochloric acid and 

 treated with sulphuric acid and alcohol, gave, from the filtrate of the 

 sulphate of strontium, 0.148 gr. selenium or 0.2079 gr. selenious acid. 



Calculated on 100 parts: 



experiment theory 

 1. 2. 3. 4. 5. 6. 

 Strontia .... 37.27 37.40 — — — — 2SrO 207 37.29 

 Selenious acid — — — — — 40.18 2Se0 2 222 40.00 



Water — — 22.55 22.36 22.59 — 7H 2 126 22.71 



555 TooToo 



