Products of heating Ammonium Sulphites, 

 Thiosulphate, and Trithionate. 



By 



Edward Divers and Masataka Ogawa, 



Imperial University, Tokyo. 



What lias been published upon the effects of heating am- 

 monium sulphites and thiosulphate is but little in accordance 

 with the results of experiments we have had to make upon these 

 salts and upon the hardly known trithionate, in connection with 

 an investigation of the decomposition by heat of ammonium 

 araidosulphite. We therefore make known what we have ascer- 

 tained. 



Preparation of the salts used. 



Ammonium sulphite, (NH4)2 SOo, OHo. — Statements are con- 

 flicting as to whether this salt can be got from its solution by 

 evaporation (Muspratt, Phil. Mag., 1847, iii, 30, 414 ; Marignac, 

 Jahresb., 1857, 17 ; Forcrand, Compt. rend., 1885, 100, 245 ; 

 Hartog, Compt. rend., 1887, 104, 1793 ; Eoehrig, J. pr. Ch., 1888, 

 37, 227). We find that a concentrated solution, charged with 



