56 



DIVERS AND HAGA. 



boiling :ind condensing unchanged for the most part. A^ery slowly, 

 however, even when more strongly cheated, it decomposes into nitro- 

 gen, ammonia, water, sulphur dioxide, and sulphur trioxide, thus : — 



6HN(S()3Am)â='2N2+14NH3+60H„-|-6S02+6S03, 

 these ])roducts then ]mrtly condensing and yielding finally — 

 '2N2+ 2NH,+ SSaOsAmoH- HOCSOsAm),. 



The little ammonia first given off without niti-ogen is no doul)t 

 attriljutable to the action of moisture in the somewhat deliquescent salt. 

 This water would cause the hydrolysis of its molecular equivalent of 

 the salt into amidosulphonate and acid-sulphate, and then, by further 

 heating, int(j pyrosulphate and ainmoni;i : — 



HNlSOBÂm),-!- H2O = HsNSOsAm-t- HOSOsAm = H3N + OiSO^Am)., 



Experiments, as yet unpublished, by one of us h.ave fully estab- 

 lished the existence of the undescribed salt, 0(lS():5Am)o. aimnonium 

 pyrosulphate. 



Trianimoniwii imidosulithouaU' Ciifdrated). — This salt, hitherto un- 

 described, is formed by the union of ammonia with diammonium 

 imidosulphonate in the presence of water. The ammonia must l)e in 

 excess as else the salt is |)artly decomposed by \Nater. Tlie most con- 

 centrated ammonia-water ] )reci pitates it from a saturated solution of 

 the diammonium salt ; also^from a concentrated solution of the diso- 

 dium salt, but then it is mixed with sodium ammonium salt (p. 75) 

 Ammonia-gas acts similarly and much more effectively. Thus ob- 

 tained, it forms a crystallinej)owder, l)ut it «'an be got in large crystals 

 by dissolving it, or the diammonium salt, to saturation in moderately 

 stronn- ammonia-water, in a closed vessel bv the aid of heat, and 

 settinj2r the solution aside to cool. It is also üot, and in the laro-est 

 crystals, by evaporating its anunoniacal solution in a desiccator, 



