306 E. DIAŒRS AND T. H AG A : 



vacuum-desiccator, the amidosulphnric acid will crystallise out 

 from the sulphuric acid with which it is accompanied (this 

 Journal, g, 230). We have purified tlie acid by recrystallisa- 

 tion, and have hydrolysed it ;it 150°, by means of hydrochloric 

 acid, into acid ammonium sulphate ; we have also completely 

 volatilised the acid by heat thus proving the absence of base 

 accidentally derived. 



Nitrosyl sulphate dropped into much excess of cooled solu- 

 tion of sulphur dioxide also yields the hydroxyamidosulphate re- 

 action with copper sulphate and potassium hydroxide. 



IV. — b. Influence of the Base of the Nitrite or Sulphite. 



Although Fremy held that sulphurous and nitrous acids 

 combine together, he did not believe that the resulting sulph- 

 azotised acids could be obtained in this way, because of their in- 

 ability to exist in absence of a base. Moreover, he considered 

 that a strong base is influential in bringing about the formation 

 of these acids, even though he had had no success with such a 

 base as sodium. The only hydroximidosulphates he could prepare, 

 indeed, were those of potassium, but from ammonium nitrite he 

 got the nitrilosulphate, and also obtained evidence that calcuim, 

 strontium, and barium nitrites are convertible into amidated 

 sulphates. 



We have just shown (sect. IV. a.) that the interaction of 

 sulphurous and nitrous acids does not require the presence of 

 any base at all for the actual production of sulphazotised acids, 

 although such presence is essential to preserve unchanged the 

 first product of the interaction. To serve this purpose some 

 bases will doubtless be inferior to others, and those w^hicli do 



