lMli)U8ULPHÜXATES. g 3 



exjDerimeiits. fused, und then gi-adiuilJy solidified ;is the decomposition 

 proceeded. The salt used was not, howeNer, pure, being mixed with 

 potassium sulphate. 



The effect of heating di potassium imidosulphonate has heen 

 studied by us. Xot below the softening point of soft lime-glass does 

 the dry diijotassiinn salt, in a dry atmosphere, sutfer any notable 

 change. In a ISprengel-])umj) vacuiuii it evolves gas only very 

 slowly and of Nery small tension, and yields besides only some very 

 slight sublimates between o 60° and 440." At the temperature of its 

 actual decomposition it melts and boils. The decom])osition which 

 then occui's is expressed by the equation — 



The ammonia and some of the sulphur dioxide condense to form a 

 rather vol;itile yellow-brown pseudo-sublimate and a less volatile white 

 pseudo-sublimate, both of which readily yield ammonia and sul])hur 

 dioxide aiiain when tested in water. The brown sublimate aives a 

 clear and colourless solution. Ijoth sublimates ap))ear to be bodies 

 ol)tained by Rose from su]j)hur dioxide and ammonia, i'robably, 

 from wliat Meute has done, the yellow" body is nitrogen sulphide and 

 the wdiite is sulphamide. The permanent gases consist of one measure 

 of nitrogen to somewhat more than two of sulphui- dioxide. We had 

 expected to be able to get evidence of the intermediate formation of 

 nitrilosulph(jnate — 3HN(S03K)2 = H,N-f-2X(803K)3— by arresting the 

 decomposition betöre it liad gone very tar, and by careful regulation of 

 the temperature, but we could not do so, any more than in the case of 

 the diammonium salt. 



Fremy (jbserved the formation by heat of potassium sulphate, 

 sulphur dioxide, and ammonia, and of the coloured sublimate. Claus 

 and Koch recorded the decomposition of the salt above 200" sharply 

 into the same bodies. Hut neitlier chemist mentions the still more 



