Dr. Hofmann on Sulphamidobenzamine. 163 



Not less decisive is the evidence furnished by the products of 

 decomposition of the two bodies. The most characteristic trans- 

 formation of urea is its decomposition into ammonia and carbonic 

 acid when it is submitted to the action of the alkalies. A compound 

 urea thus treated should yield, together with carbonic acid and 

 ammonia, the monamine from which it has arisen. Phenyl-urea 

 should furnish carbonic acid, ammonia, and phenylamine : these are 

 precisely the products observed in the decomposition of the com- 

 pound which is formed by the action of cyanic acid on phenylamine. 



(CO)"] H1 HI C 6 H 5 



c 6 h 5 In 2 +hJo=(co)"o+hIn+ h \ 



Amidobenzamine, on the other hand, exhibits with potassa the 

 deportment of an amidated amide. The reaction presents two di- 

 stinct phases, ammonia and amidobenzoic acid being formed in the 

 first phase, and ammonia and benzoic acid in the second : 



C,(H,|N)01 + H| 0= |j N+ C,(H 1 H a N)Oj 

 C,(H 4 H ! N)Oj + HJ <) = || N+ C 7 H s O| 



No trace of carbonic acid and no trace of phenylamine are elimi- 

 minated by potassa. It is only by fusing with soda-lime that a 

 perfect destruction of the compound ensues, when, as Chancel has 

 distinctly observed, in the first place ammonia, and ultimately car- 

 bonic acid and phenylamine are evolved. 



What I have said respecting phenyl-urea applies with equal force 

 to diphenyl-urea. Gerhardt describes as diphenyl-urea the com- 

 pound obtained by Laurent and Chancel when they examined the 

 action of reducing agents upon nitrobenzophenone, and which, on 

 account of its yellow colour, was originally described as Jlavine. 

 This body contains C TT N O 



which is certainly the formula of diphenyl-urea. But here again 

 chemists have been misled by the basic properties of the substance. 



It is not my object at present to dwell on the constitution of 

 flavine, which I intend to examine in a subsequent note ; suffice it to 

 say that this substance is not diphenyl-urea. 



The true diphenyl-urea is the substance commonly called carbani- 

 lide, or carbophenylamide. 



(coyn 



C 18 H ]2 N a O=(C 6 H 6 )AN 2 . 



H 3 J 



Both the conditions under which this body forms, and the pro- 

 Hi 2 



