206 EDWARD DIVERS AND SEIHACHI HADA ; 



sensitive. The sait is also of interest because, in mode of 

 formation and in properties, it closely resembles ethyl ammo- 

 niumsulphite (see preceding paper), although the work of 

 Michaelis and Landmann {Ann., 1887, 241, 150) seems to 

 have established that nothing analogous to a sulphonic constitu- 

 tion presents itself in alkyl selenites. One of us has also pointed 

 out {J. Chem Soc, 1886, 49, 585) some special points of 

 similarity of silver and mercury selenites to silver and mercury 

 sulphites, although their alkyl derivatives are differently con- 

 stituted (Michaelis and Landmann, loc. cit.). 



The selenion dioxide for making the new salt was prepared 

 from selenion of high purity, which had been obtained, years 

 ago, from the * red sulphur ' of Japan, by M. Shimose and one 

 of ourselves. The anhydride being very hygroscopic, special 

 care had to be taken to ensure its freedom from hydration when 

 used. The selenion was dissolved in nitric acid, the solution 

 evaporated to dryness, and the residue repeatedly moistened 

 with water and dried again by heat. The resulting selenious 

 acid was kept for some time, in an open dish, close to the 

 subliming point of the anhydride. Thus almost dehydrated, it 

 was transferred hot to a glass tube in which it was several 

 times sublimed in a current of dry oxygen. Finally it was 

 again volatilised into and deposited in the well dried experi- 

 mental vessel itself. 



Great care was also taken to dry the alcohol in the usual 

 way and then to keep it almost out of contact with the air. 

 The ammonia too was well dried, not so effectively, perhaps, 

 as the alcohol and anhydride, yet sufficiently so, as the result 

 of its use proved. 



The selenion dioxide with about five times its weight of 



