450 
DE. A. W. H0F:MAN']S' ox the phosphoeus-bases. 
Material for building up this group of bodies appeared to present itself unmistakeably 
in the chlorine-, bromine-, and iodine-compounds of ethylene and its homologues. As 
some years ago I had succeeded in converting the corresponding ethyl-compounds by 
the action of ammonia into the monacid ethyl-bases, I was justified in expecting that, 
by treating the ethylene-compounds with ammonia, diacid bases might be formed. 
Respecting some of the bodies which are produced in these reactions, investigations had 
already been published by Cloez*, and more recently by XATAXSOxf, whose results 
appeared at first sight to give but little encouragement to any such attempt. But a 
careful examination of these researches soon convinced me that, when riewed by the 
light which the progress of science has since thrown upon this subject, the results 
elicited are far from unfavourable to my theoretical conceptions. 
I have once more studied these reactions, and have obtained experimental con- 
firmation of the correctness of my anticipations. But the action of ammonia on the 
chloride, bromide, and iodide of ethylene presents unexpected complications, quite 
independent of those indicated by theory, and for which I was not altogether prepai'ed. 
Consider for a moment the manner in which the reaction between ammonia and a 
diatomic bromide — dibromide of ethylene for instance — may take place. Just as bromide 
of ethyl, acting, as it does, on a single molecule of ammonia, gives rise to the formation 
of the four bromides, 
[(C^H,) H3N]Brt 
[(C2H5),H2N]Br, 
[(C2H3)3H N]Br, 
and[(C,H5)4 N]Br, 
so likewise may dibromide of ethylene, acting on two molecules of ammonia, be expected 
to produce four diatomic bromides, viz. — 
aiKl[(C2Hj); N2]''Br,. 
These, however, are by no means the only compounds which, in accordance with oin 
present conception of diatomic compounds, may be formed in this reaction. 
It appears from the researches of Wuetz, that dibromide of ethylene does not pass 
into ethylene-alcohol at a single bound, but that there exists an intermediate member of 
the series still containing half the bromine. 
Dibroinide of 
Ethylene. 
(anj 
Br 
IHO 
Intermediate 
Bromide. 
Ethyleue- 
aleoliol. 
* Instit. 1853, p. 213. 
+ 11 = 1; 0=16; S=32; C = 12, etc. 
t Ann. Chem. Phariu. xcii. dS. and xcviii. 291. 
