IMIDOSULPHOXATES. 5 J 



Berglund's discovery that they issue from the interaction both of 

 sulphur trioxide and ammonia, and of sulphiu- dioxide and a nitrite, 

 supplied a beautiful, if not needed, confirmation of Claus's theory. 



Although, as we shall demonstrate. Rose, Jacquelain, Fremy, and 

 Woronin had all prepared imidosulphonates with three equivalents of 

 base, as well as witli two, to one of nitrogen, yet no clear conception 

 of these compounds as salts of a nioi'e than bibasic acid had been 

 formed l)efore they were examined by Ikrglund and shown by him 

 to be derivatives of a tribasic acid, one in ^^hich the aminic, as well as 

 the sulphonic, hydroo-en is basic. He prepared for the first time 

 tripotassium and some other trimetal salts. 



It will be seen that the existence of imidosulphonates with three 

 equivalents of base, first made evident by Berglund, constitutes a 

 misnomer the term imidosulplionate, which he liimself introduced, 

 since' in these salts the third hydrogen of ammonia is gone. But no 

 simple way out of the difficulty presents itself, and we adopt it, there- 

 fore, as Raschig and Mente have done before us. 



Imiilosulphonic Acid. 



Iraidosulphonic acid, IiN(S03H)2, has been obtained only in 

 solution. It was first prepared by Jacquelain. We have followed his 

 process, which consists in treating the lead salt in water with hydrogen 

 sulphide, and made it our special care to have the lead salt as free as 

 possible from sodium. The lead salt was decomposed by the hydro- 

 gen sulphide with a very sensible elevation of temperature, and this 

 strengthened our expectation that the acid must hydrolyse almost as 

 fast as it forms. But such is not tlie case, and i-apid filtration over 

 the pump gave a concentrated solution containing very little sulphuric 

 acid, and therefore very little amidosulphonic acid. 



The imidosulphonic acid was fully identified by its giving an 



