4.26 



Dr. A. W. Hofmann on the [June 20, 



of the mustard-oils, my attention was in the first place directed towards the 

 production of the ethylene term of this class of compounds, and I was thus 

 led to make some experiments on the behaviour of the diamine towards 

 carbon bisulphide. Indeed, if the reaction between these two bodies ensued 

 in a manner analogous to that which obtains in the case of carbon bi- 

 sulphide and ethylamine, the formation of an ethylenediamine ethylene 

 disulphocarbamate, 



(CS) 2 (C.HJH.Xl, 

 (C,H 4 ) H 4 N„ H,r* 



was to be expected, which, under the influence of metallic salts, might have 

 split up in ethylenediamine, sulphhydric acid, and ethylene mustard- oil, 



(C ||^ J; £ } S = 2H 2 S + (C a HJ H, N a + (CS) a (C 2 HJ N,. 



Ethylenediamine sxdphocarbonate. — If carbon bisulphide be mixed with 

 a solution of ethylenediamine in alcohol, a clear liquid is obtained, which 

 after a few moments becomes troubled by the separation of a white, almost 

 amorphous compound. This substance rapidly augments, so that after the 

 lapse of a quarter of an hour the liquid is converted into a white or pale 

 yellow solid mass. 



The new compound is nearly insoluble in alcohol and ether, and may 

 therefore be readily purified by washing with these solvents. It is soluble 

 in hot water, undergoing, however, at the same time slight decomposition ; 

 if care be taken not to heat the solution to the boiling-point, the compound 

 separates on cooling in prismatic crystals. In the dry state also it is decom- 

 posed at a temperature of 100°, and must therefore for analysis be dried 

 in vacuo or over sulphuric acid. Analysis shows that the substance is 

 formed by the union of one molecule of ethylenediamine and one molecule 

 of carbon bisulphide, its composition being expressed by the formula 



C 3 H 3 N 2 S 2 =(C 2 H J H 4 N a , CS 2 . 

 The behaviour of ethylenediamine to carbon bisulphide is therefore so 

 far analogous to that of ethylamine that we have, in both instances, a double 

 molecule of ammonia uniting with one molecule of carbon bisulphide. 

 The ethylenediamine derivative, however, is distinguished from that of ethyl- 

 amine by its chemical characters ; for whilst the latter is evidently the 

 ethylamine salt of ethylsulphccarbamic acid, a similar view of the consti- 

 tution of the former is untenable ; for neither do dilute acids cause the sepa- 

 ration from it of ethylene sulphocarbamic acid, nor do alkalies liberate 

 ethylenediamine, reactions which would certainly take place if the new 

 body were constituted like the ethylamine compound. Under these cir- 

 cumstances there was but little expectation of meeting amongst the pro- 

 ducts of its decomposition an ethylene mustard-oil having the compo- 

 sition of ethylene salphocyanate described by Buff. In fact I may state 

 at once that hitherto all my attempts to prepare such a compound have 

 entirely failed. 



