Dr. Hofmann on the Diatomic Ammonias. 67 



the formation of diatomic bases by the action of diatomic bromides 

 on ammonia. I have given the proof in several communications* 

 addressed during the last two years to the Royal Society, and 

 especially in a notef describing some new derivatives of phenylamine 

 and ethylamine published during last summer. The formation of 

 these bodies, their analysis and their transformations, have, I believe, 

 settled the question at issue in a satisfactory manner. 



These researches have been the subject of some remarks on the 

 part of M. Cloez|, from which it appears that this chemist has 

 interpreted my silence as a tacit admission of defeat ; he rejects the 

 formulae which I have given for the diatomic derivatives of phenyl- 

 amine and ethylamine, and blames me for having continued my 

 researches on the diatomic bases without having previously replied 

 to his observations. 



Under these circumstances I have been compelled to resume the 

 investigation of the action of dibromide of ethylene upon ammonia, 

 and to reply, after nearly two years have elapsed without M. Cloez's 

 paper having been published, to the series of objections which this 

 chemist has raised against the theory of the diatomic bases. 



Since this continuation of my experiments throws considerable 

 light upon this new class of compounds, I beg leave to submit them 

 to the judgment of the Royal Society. 



In order to render more intelligible the line of argument which 

 M. Cloez has brought forward against the diatomic notions, it will 

 be useful to recapitulate in two words the subject of our controversy. 



M. Cloez admits that in the action of dibromide of ethylene upon 

 ammonia, the molecule of ethylene splits into radicals belonging to 

 three distinct groups, viz. the formic, acetic, and propionic series ; 

 these radicals acting upon one molecule of ammonia, in which each 

 of them replaces one equivalent of hydrogen, give rise to the forma- 

 tion of three primary monamines, viz. Formenamine, Acetenamine, 

 and Propenamine. 



According to the view which I defend, the molecule of ethylene 

 remains intact in the reaction, acting upon two molecules of ammonia 

 in which 2, 4, or 6 equivalents of hydrogen are replaced respectively 

 by 1, 2, or 3 diatomic molecules of ethylene; the dibromide of 

 ethylene gives rise to the formation of three diamines belonging to 

 the same family, a primary, a secondary, and a tertiary diamine. 



Expressed in formulae the two views may thus be represented : — 



Formula of M. Cloez. „ 



Formenamine C 2 H 3 N= H \ N. 



H J 

 C 4 H 3 ] 

 Acetenamine C 4 H 5 N= H \ N. 



H J 



Propenamine C 6 H 7 N= H \ N. 



H J 

 * Phil. Mag. vol. xvii. pp. 66, 133 ; xviii. p. 148. f Ibid. vol. xix. p. 232. 

 % L'Institut, 1859, p. 233. 



F2 



