430 COLLECTED STUDIES IN IMMUNITY. 



CH 2 



Bromethylamine = 



Since then, however, Marckwald has positively shown (1900- 

 1901) that this substance cannot, as was at first supposed, contain a 

 double bond (ethylene combination), for it does not reduce per- 

 manganate at ordinary temperature nor take up bromine. It can. 

 therefore only possess the constitution of a dimethylenimin: 



CH 2 \ 



NH 



In view of this a complete analogy exists between the ethylenimin 



and the ethylenoxid: 



2 v 

 



In conformity with Bayer's tension theory we must ascribe an 

 extraordinary tension to the three-sided ring contained in the di- 

 methylenimin. This manifests itself also in the fact that this sub- 

 stance shows a marked tendency, through the addition of acid radicals- 

 and the breaking of the ring, to pass over into a substituted ethyl- 

 amin of the chain series. Thus, as Gabriel showed, HC1 is added with 

 the formation of chlorethylamin, and sulphurous acid with the forma- 

 tion of taurin. These reactions proceed with great energy, as is 

 shown by the fact that even in dilute watery solutions of the freshly 

 prepared hydrochloride an alkaline reaction dewlops within a few 

 minutes, due to the formation of free chlorethylamin which reacts 

 alkaline. 



Ethylenoxid behaves in an analogous manner. This is shown 

 in surprising fashion by the fact that this neutral body precipitates 

 magnesia out of chlormagnesium, iron oxide out of iron chloride, 

 entirely after the manner of free alkalies. In doing so it adds the 

 acid radical and becomes transformed into chlorethylalcohol. 



These two substances, ethylenimin and ethylenoxid, are highly 

 toxic combinations as has been shown by the researches of Levaditi 

 and myself. The pathological changes excited by dimethylenimin 



1 I have taken the liberty of somewhat modifying the text of this chapter 

 in accordance with the positive advance of our knowledge, which we owe to 

 the labors of Marckwald. 



