AMMONIUM AND OTHER IMIDOSULPHITES. 6 



that of a fourth only of the weight of decomposed amidosulphite 

 taken, but the total production of imidosulphite will no doubt prove 

 to be very much greater. 



Analysis. — The salt, 0.4240 gram, distilled with potash yielded 

 ammonia, 0.0817 gram, and then after heating for some time in a 

 pressure-tube with hydrochloric acid and again distilling with 

 potash, 0.03755 gram more ammonia. Simple distillation with 

 potash of 0.4912 gram of another portion of salt gave 0.0939 

 gram of ammonia, and then, after oxidation by means of bromine 

 followed by hydrochloric acid and potassium chlorate, 1.2886 grains 

 of barium sulphate. The calculated and found precentages are : — 



It will be seen that the analysis establishes not only the com- 

 position of the salt to be 3NH 3 ,2S0 2 but also its imide constitu- 

 tion. 



Properties. — It occurs in minute micaceous needles. Heated 

 very slowly in a tube it soon begins to decompose into volatile 

 substances and a residue of sulphur, ammonium sulphate, and the 

 2 /a normal ammonium imidosulphate [NtT(S0 3 NH 4 )J. Even when 

 the temperature is raised to 150°, no fusion takes place. The 

 sublimates which form during the heating begin to appear at 

 about 80° and consist apparently of ammonium pyrosulphite 

 [(NH 4 ) 2 S 2 5 ], and the unchanged imidosulphite [(NH^CXNH]. 

 The salt is insoluble in alcohol, and in this respect is unlike 

 ammonium amidosulphite, which is very soluble as ethyl ammonium- 



