268 



zoic acids, but the chemical deportment of these substances is altoge- 

 ther different from that of the analogous derivatives of acetic acid. 



Further experiments are necessary to establish this view; the 

 existence of two varieties of lactic acid, and of alanine and sarcosine, 

 which are both represented by the formula 



C 3 H 7 N0 2 , 



appears to indicate that similar isomerisms obtain also in the group 

 of fatty acids. 



The above observations were collected in Dr. Hofmann's labora- 

 tory. 



VIII. " On the Ureas of the Diamines." By J. VOLHARD, Ph.D. 

 Communicated by Dr. HOFMANN. Received May 24, 1861. 



The action of cyanic acid and of the cyanic ethers on the mona- 

 mines gives rise to the formation of the substances known as the 

 compound ureas. By substituting diamines for the monamines in the 

 above reaction, I have succeeded in producing a series of compound 

 ureas of a higher order, which are remarkable for their well-defined 

 properties and for their characteristic decompositions. 



Dichloride of ethylene-diammonium is readily attacked by cyanate 

 of silver. On evaporating the solution, separated from the chloride 

 of silver, a new substance crystallizing in prisms is obtained, which I 

 designate as ethylene-urea. This body is soluble in water and 

 alcohol ; it contains 



(coy 



C 4 H 10 N 4 O a = (C 2 H 4 )" 



and is formed by one molecule of ethylene-diamine combining with 

 two molecules of cyanic acid. 



Ethylene-urea fuses at 192 C. It dissolves easily and without 

 decomposition in hydrochloric or nitric acid, without, however, com- 

 bining with these acids ; the acid solutions, when evaporated to dry- 

 ness, leave the pure ethylene-urea. When boiled with a very concen- 

 trated solution of potassa, this body assimilates the elements of water 

 and splits into carbonic acid, ammonia, and ethylene-diamine, 



* H = l ; = 16; C = 12, &c. 



