274 



III. " Notes of Researches on the Poly-Ammonias/' No. III. 

 Contributions towards the History of the Diamides ; Cya- 

 nate and Sulphocyanide of Phenyl. By A. W. HOFMANN, 

 Ph.D., F.R.S. &c. Received May 7, 1858. 



About ten years* ago, when engaged in the study of aniline, I 

 discovered two beautiful crystalline compounds, carbanilide and 

 sulphocarbanilide, which can be produced by a variety of processes. 

 The former is best prepared by the action of phosgene-gas on ani- 

 line, while the latter is most readily and most abundantly procured 

 by the action of bisulphide of carbon on aniline. The composition 

 and the constitution of these bodies is indicated by the formulae 



(C 2 2 )" 

 Carbanilide ........ C 26 H 12 N 2 O 2 = (C 12 H 5 ) 2 



H 2 



(C 2 S,)" 

 Sulphocarbanilide . . C 26 H 12 N 2 S 2 = (C 12 H 5 ) 2 \ N 2 . 





They may be viewed as derived from two molecules of ammonia 

 (diammonia) in which two equivalents of hydrogen are replaced by 

 two molecules of phenyl, and two other equivalents by the biatomic 

 molecules C 2 O 2 and C 2 S 2 . 



The two substances in question, as far as their formulae are in- 

 volved, obviously correspond to urea and sulphocyanide of am- 



monium : 



(C 2 2 )" 

 Urea .................... C 2 H 4 N 2 O 2 = H 2 \ N 2 , 



(C 2 s 2 y 



Sulphocyanide of ammonium. . C 2 H 4 N 2 S 2 = H 2 J- N 2 . 



H 2 



In their formation likewise a certain analogy with urea and sul- 

 phocyanide of ammonium may be recognized ; for recent experiments 

 have proved that urea is actually produced by the action of phosgene- 

 gas on ammonia, while the formation of sulphocyanide of ammonium 

 by means of ammonia and bisulphide of carbon is a long-established 

 fact. The analogy, however, seems to disappear altogether, if the 



* Journal of the Chemical Society, vol. ii. 36. 



