IMIDOSULPHONATES. 53 



together with aniidosulphonate, hut no aiiiiiinni;!. The amidosul- 

 phonate would do doubt be ub.seiit but lor water taken up from the 

 air during mixing, from tlie sulphuric acid itself, and lastly, to some 

 degree, during dissolution in the Avater in s])ite of the alkali present. 

 When heated, tlie mass very readily fuses and gives off sulphuric acid 

 and sulphur dioxide. Jac(|uelain observed similar behaviour with 

 sulphuric acid, hot and cold, in diammonium imidosulphonate. 



The little action of concentrated sulphuric and nitric acids was 

 noticed by Fremy, and by Claus and Koch. Evidence, therefore, has 

 not been obtained of any action of sulphuric acid upon a, dry imido- 

 sulphonate such as would be expressed by the equation. — H]S[(803K)2 

 + 2S0 A= HN(803H),+ 280,HK. 



Aiiiinoniiuii iviidosiilpJio'tKites. 



jyiaiinuoNiuin mridosulplionate. — Diammonium imidosulphonate, 

 HN(603Am)., can be ]>i-epared from ammonia and sulphur trioxide 

 (Rose, Jacquelain, Woronin), or chlorosulphonic acid (Berglund, 

 Mente), or sulphuryl chloride or pyrosulphuryl chloride (Mente). It 

 is obtained when nitrous gas is passed into an ice-cold solution of 

 ammonium sulphite, and the product hydrolysed (Fremy). Along 

 with ammonia, it is the product of heating ammonium amidosul- 

 phonate to 160° (Berghuid). 



The decom])osition of l)arium imid«Jsulphonate by a soluti(jn of 

 anmionium sulphate can only be very imperfectly accomplished, but 

 by treating it .tirst with dilute sulphuric acid barely sufficient to 

 convert it into the soluble barium hydrogen imidosulphonate and 

 then adding annnonium sul])hate until no barium remains in solution, 

 diammonium imidosulj)honate can be ])repared satisfactorily, except 

 f(jr the incumbi-ance of the bidky barium imidosulphonate and sulphate. 

 Another procedure which can be followed is to decompose either of the 



