8 AKT. 2. — E. DIVERS AND T. HAGA. 



remove 15.5 per cent, by exposing the salt in a vacuum over 

 sulphuric acid, alter which the salt has hydrolysed and thereby 



fixed the l'est of the water. The production of the unused pyro- 

 sulphite, shown in the above equation, is necessary for the safe 

 and prompt sulphonation of all hydroximidosulphate. 



Sodium nitrilosulphate crystallises in short thick prisms 

 which melt when heated and decompose in their water of crys- 

 tallisation into sulphates. The crystals cannot be long' preserved 

 under any circumstances, soon suffering decomposition and be- 

 coming opaque and acid, even in their own mother-liquor after 

 it has been made alkaline. That is, the sodium salt is more un- 

 stable than the potassium salt. It is neutral to litmus and must 

 be soluble in about its own weight of water, to judge from the 

 amount of it left in the mother-liquor in its preparation, although 

 here, no doubt, the pyrosulphite also in solution will affect its 

 degree of solubility. 



For analysis, it was drained on the tile after washing with a 

 little strong ammonia-water, in which it is less soluble than in 

 water. Partial water determinations have already been referred 

 to. 



Potassium sodium nitrilosulphate, N(S0 3 ) 3 K 2 Xa. — Raschig 

 obtained this salt by adding a solution of potassium chloride 



