IMTDOSULPHONATES. 6 J. 



moiiia in vacuo over sulphuric acid. Having observed the loss of 

 ammonifi to l)e so slight at common temperatures, we heated the same 

 portion in a current of well-dried air for If hours at a temperature 

 of 100-120,° and then found the issuing air t(^ be still carrying 

 ammonia The salt cooled and reweighed had now lost only 5*4 

 per cent, in weight by this heating and gave with water a solution 

 which by tests showed very fully the presence of some triammonium 

 salt still. 



From what ])recedes it is evident that triammonium imidosul- 

 phonate is comparatively stable in the anhydrous state, and that Rose's 

 sulphatammon is this salt. Coming, as hei'e described, from another 

 imidosulphonate without hydrolysis, it cannot be ammonium amido- 

 sulphonate, as it is commonly assumed to be : (as in Mendeléeff' s 

 Principles of Cliemistri/, and Ramsay's System of Itumianic Chemistrif). 

 Further, its conversion by heat into parasulphatammon and ammonia 

 affords no proof that it is ammonium amidosulphonate, for this salt 

 would only change tlius at temperatures above 160.° A salt which is 

 certainly ammonium amidosulphonate can be ])repared by processes 

 which include the hydrolysis of an imidosulphonate, and this is quite 

 a, different body. According to Berglund, it crystallises in large plates, 

 and only at 160° is converted into imidosulphonate and ammonia. It 

 is not readily decomposed by water, is neutr;il in reaction, and does 

 not precipitate barium salts, tacts verified for us by our ]jupil, Mr. Y. 

 Osaka. 



Imidosulphonainide. — Mente has found that i midosulphonamide, 

 H jSr(S 00X112)2, ii^ ])roduced by the action oi' ammonia upon pyrosul- 

 phuryl chloride. Diammonium imidosulphonate, when heated to its 

 subliming ])oint, may possibly yield it, but as at common temperatures 

 it reacts at once with watei" to form diammonium imidosulphonate, 

 its presence can not be tested for. 



