271 



acid and ethylamine, differs in some of its physical properties from 

 the ethylurea obtained by the action of ammonia on cyanic ether, 

 although both substances yield under the influence of chemical 

 agents exactly the same products of decomposition, viz. carbonic 

 acid, ammonia, and ethylamine. 



The experiments described in this Note were made in Dr. Hofmann's 

 laboratory. 



IX. <e Notes of Researches on the Poly- Ammonias." No. XI. 

 Isomerism of Diatomic Compounds. By A. W. HOFMANN, 

 LL.D., F.R.S. Received May 24, 1861. 



The experiments which Dr. Volhard has described in the previous 

 Note, remind me of some analogous observations which I made some 

 time ago in the case of oxalyl-derivat'ives. 



While engaged in experiments on the separation of the ethyl 

 bases by means of oxalic ether, which I have had the honour of 

 laying before the Royal Society*, I had collected a considerable 

 quantity of diethyloxamate of ethyl, 



which is formed by the action of oxalic ether upon diethylamine. I 

 have studied the deportment of this compound under the influence 

 of several agents. 



When digested with alcoholic ammonia in sealed tubes, diethyloxa- 

 mate of ethyl is rapidly converted into a crystalline compound, which 

 on analysis was found to contain 



C 6 H 12 N 2 2 , 



showing that the reaction is accomplished in the form pointed out 

 by theory, 



(0,0,)" (C.H.XN 



The new compound then has the composition of diethyloxamide, 



but it is far from being identical with the splendid body which is 



formed by the action of oxalic ether on ethylamine. It differs from 



the latter in many of its properties, being in fact much more soluble 



* Proceedings, vol. xi. p. 66. 



