Dr. Hofmann on Sulphocyanide of Phenyle. 63 



" Contributions towards the History of the Diamides ; Cyanate 

 and Sulphocyanide of Phenyle." By A. W. Hofmann, Ph D 

 F.R.S. 



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

 discovered two beautiful crystalline compounds, carbanihde and 

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

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

 hne, 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 formulEC 



(c. o,)'n 



Carbanilide C,, H^, N, 0,= (C,, H,), K N„ 



Sulphocarbanilide . .C„,U,^'i^^^.,=l<C^,B..\ )>N„. 



■h! J 



They may be viewed as derived from two molecules of ammonia 

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

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

 molecules C, O.^ and C^ S^. 



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

 volved, ob-^iously correspond to urea and sulphocyanide of am- 

 monium : — 



Urea C,H,N,0,= H, I N„ 



h: J 



(C,S,)"] 

 Sulphocyanide of ammonmm . . C^ H.j N.^ S, = H^ }• N^. 



' H, J 



lu 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 

 chemical nature of the four bodies be compared, for while urea 

 exhibits the deportment of a base, and the saline character of 

 sulphocyanide of ammonium is so well defined, carbanilide and sul- 

 phocarbanilide are apparently perfectly indifferent substances. 



Nevertheless, on considering the difference of the chemical pro- 

 perties of urea and sulphocyanide of ammonium, and on recollecting 

 that the saline constitution of urea is much more hidden than that 

 of sulphocyanide of ammonium, it appeared worth while to try 

 whether the action of powerful agents would not reveal a similar, 

 if I may use the term, saline construction in carbanilide and sulpho- 

 carbanilide. Experiment has realized this anticipation. 



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



