AMMOXIUM AMIDOSULPHITE. 197 



solid again and tenaciously adherent to the glass. When i)ure 

 ammonium amidosulphite is similarly heated in a dry inactive 

 gas, it colours, softens, shrinks together, vesiculates, gives out 

 ammonia, and becomes a mass like that derived directly from 

 the union of the gases. With very gradual heating, the tem- 

 porarily liquid product is much less coloured than in the other 

 case, its colour being evidently caused by the presence of a 

 red matter dissolved in it, wliicli gives indications of being- 

 volatile. 



This orange-red substance is never formed in more than 

 very small qua.ntit3^ It gives a yellow colour to the aqueous 

 solution of the whole product, which, however, slowly fades away. 

 Alcohol, carbon bisulphide, and other menstrua dissolve it out 

 from the salts, leaving them white ; but the solutions are not 

 pure. The yellow solution in water or alcohol takes a transient 

 pink colour Avhen mixed with dilute hydrochloric acid, and the 

 alcoholic solution an indigo-blue colour with concentrated am- 

 monia. The residue left on evaporating the carbon- bisulphide- 

 solution becomes explosive when heated above 150°, and may 

 then have become nitrogen sulphide, but before being heated it 

 is not this substance. 



Except the very little sulphate already mentioned, there is 

 no as-yet known substance present in the residue of the decom- 

 position of the amidosulphite by a gentle heat, so far as we can 

 discover. Alcohol of 00 per cent, dissolves out something, but 

 only very sparingly. By evaporation of the solution in a vacuum 

 desiccator, a very deliquescent salt is obtained in crystals, having 

 a composition that may be expressed by 9NH3, 8SO2, assuming 

 the presence of 2.5 per cent, moisture. The composition of the 

 whole crude residue does not differ much from this. The alco- 



