AMIDOSÜLPHOXIC ACID. 257 



heat, according as they concern the acid or its barium salt, the am- 

 monium or the potassium salt, the characteristics of the decomposition 

 are the same. Always there is, virtually, the change of two mol. 

 amidosulphonate into imidosulphonic acid and ammonia and, for the 

 most part, the union of these to form a normal salt : — 



2H 2 NSO H = NH 3 + HN(S0 3 H) 2 ; (H 2 NSO s ) 2 Ba = NH s + HN(S0 3 ) 2 Ba. 

 That change is the cumulative resolution of an amine ; next comes the 

 cumulative resolution of the imidosulphonate as a hydroxide or met.il- 

 loxide. The elements of one mol. water and, in the case of metal 

 salts, one mol. basic oxide, go from one mol. of the imidosulphonate to 

 another mol. of it, converting this into sulphate, pyro or normal, as 

 the case may be, and leaving either pyro-imidosulphonate as a residue, 

 or (when basic oxide has been also lost), nitrogen, ammonia, and 

 sulphur dioxide as representatives of what, at lower temperatures might 

 have been sulphimide : — 



. 2NH 4 N(S0 3 B) 2 =(NH 4 S0 3 ^ 2 + NH 4 N(S0 2 ) 2 ; 

 2NH 4 N(S0 3 ) 2 Ba=2BaS0 4 -p2NH 3 + r2HNS0 2 j. 



The complex [2HNSOJ appears as §(NH 3 +N 2 + 3SO,), or, in the 

 case of the barium salt (infusible as that is and acquiring a higher 

 temperature as it does), this complex partly interacts with the 2NH 3 , 

 according to the equation : — 



2NH 3 + 2HNSO,=40H 2 +2NS + N,. 



We are indebted for their kind assistance, to Mr. Y. Osaka, B. Sc. 

 in examining the reactions of silver amidosulphonate, and to Mr. M. 

 Chiknshige, B. Sc, in examining the compound of amidosulphonic acid 

 with sodium sulphate. 



