IMIDES OF RENZENEDISULPHONIC ACIDS. 17 



-SO.,v -SO^H 



> NOH + NH, = + N, + H, 0, 



-SOs'^ -SO,H 



the group SO2 being directly attached to the benzene ring. In 

 order to ascertain to what extent this reaction takes place, the 

 nitrogen gas liberated by the action of ammonia upon m-benzene- 

 disulphoxime was measured in the following manner. 



0.1387 gr. of m-beuzenedisulphoxime crystals containing ace- 

 tone was put into a small thin glass bulb, which was evacuated 

 by means of a water-pump and then sealed. This bulb was 

 introduced into a wider tube of about 100 c.c. capacity, the lower 

 end of which had been drawn out and sealed. The upper end 

 of the tube was then drawn out to a capillary, through which 

 moderately strong ammonia water was introduced, until about 

 one third of the tube was filled, and the capillary connected with 

 the water pumj^ in order to evacuate the tube. The ammoniacal 

 liquid effervesced, and the escaping ammonia gas completely drove 

 away the air from the tube in a few minutes, when the latter 

 was sealed up at the capillary. The tube was then shaken 

 violently so as to break the small bulb in it. The shaking was 

 continued for a few minutes in order to ensure the complete 

 liberation of the nitrogen. After the completion of the reaction 

 the tube was opened under water, which had been previously 

 boiled to expel the dissolved air, and the nitrogen was transferred 

 into a graduated tube and measured. The volume of nitrogen, 

 reduced to 0° and 760 m.m., amounted to 11.3 c.c, while, accord- 

 ing to the equation given above, it ought to have been 12.2 c.c. 



We may, therefore, conclude that the equation actually re- 

 presents the reaction which takes place between the sulphoxime 

 and ammonia. The small deficiency of nitrogen can readily be 



