IMIDES OF BENZENEDISULPHONIC ACIDS. 19 



b) Sulphur. 



0.1272 gr. gave 0.230.5 gr. barium sulphate. 



Sulphur found 24.88^ 



,, calculated 24.82 „ 



Ammonium p-benzenedisulphinate. 



a) Nitrogen. 



0.0939 gr. gave 8.7.5 c.c. of moist nitrogen at 17° and 7.'38 ni.m. 



Nitrogen found 10.7 ^^o 



Calculated for 0,11^(802 NH,)o, IIa 10.9,, 



h) Sulphur. 



0.0966 gr. gave 0.1729 gr. barium sulphate. 



Sulphur found 24.6 «^ 



,, calculated 24.8 ,, 



The silver salts of m- and p-benzenedisulphinic acids were 

 also obtained. The former is crystalline, while the latter is 

 amorphous and difficult to purify. Silver m-benzenedisulphinate 

 was analysed with the following result : 



0.0900 gr. gave on ignition 0.0466 gr. of metallic silver. 



Silver found bA.^o/o 



Calculated for C^H^ (SO, Ag)^ .51.4,, 



The zinc salt of the meta-acid is soluble, but that of the 

 para-acid is only slightly soluble in water. 



The peculiarity of the reaction between the sulphoxime and 

 ammonia reminds one of the decomposition of ammonium nitrite 



