IMIDÜSULPHONATES. 57 



over solid potassium hydroxide and in a stroiig-ly ammoniacal 

 atmosphere. 



The crystals resemble those of the tripotassium salt and are, 

 therefore, asymmetric. They are clear and lustrous, but gradually 

 eliloresce ("mostly through loss of ammonia) and become opaque and 

 damp. The saJt when dry smells mildly of ammonia, and its crystals 

 in a dry ammoniacal atmosphere over solid potasssium hydroxide very 

 slowly become anhydrous and opacpie throughout, while retaining 

 much of their lustre and hardness. 



Heated,. the salt becomes, mainly, the diammonium salt, but to 

 some extent it melts, loses both ammonia and water, and hydrolyses 

 into sulphate. 



Dissolved in water it decomposes, but very incompletely, into the 

 diammonium salt and ;inim(niia, and the solution evaporated in the 

 open air yields crystals of only the diammonium s'ait. Hence, when 

 eithei- the trisodium or the tripotassium salt is mixed with ammonium 

 chloride, much ammonia is liberated. 



It was analysed sufficiently by heating it to 160° very gradually, 

 in a current of dried air, in order to determine the water and third 

 atom of ammoni;i. The sulphur was also estimated, and the salt Avas 

 thus proved to liave a composition analogous to that of the potassium 

 salt, namely, AmN(S03Am).2, OH.,. AVhen analysed the crystals 

 were damp but transj^arent, after rapid pressure in filter paper and 

 weighing. 



Calc. Found. 



Sulphur 26-0 1^5*4 



Loss at 160° 14-2 16-9 



A nhi/droiis triam.iiioniuni, imidosulphonate. Sulphatanimon. — An- 

 hydrous triammonium imidosulphonate is, as we shall show, Rose's 

 sulphatammon. Rose found that dry ammonia conducted into a flask 



