148 



Dr. Hofmann on a New Series of Bodies 



[Recess, 



II. " On a New Series of Bodies Homologous to Hydrocyanic Acid.-*^ — 

 II. By A.W. Hofmann, LL.D., E.R.S. Received August 31, 1867. 



In a letter submitted to the Royal Society some weeks ago I directed 

 attention to a new series of homologues and analogues of hydrocyanic acid, 

 generated by the action of chloroform on the primary monamines. As a 

 representative of this group of bodies, I described the cyanide of phenyl, 

 the formation and the properties of which had been almost exclusively the 

 subject of my researches. 



I have followed up the study of these new bodies, which have become 

 more and more attractive to me in proportion as I investigated their nature. 

 Being formed in a well-defined reaction, endowed with properties quite 

 unexpected, stable in certain cases, and of extreme alterability in others, 

 capable of the most varied reactions that can be imagined, these bodies 

 possess all the characters which invite a detailed examination. Thus I 

 find myself at the threshhold of a long investigation, the results of 

 which I beg permission to submit to the Royal Society in the order in 

 which they present themselves. 



Cyanide of Ethyl. 



After having fixed in the phenylic group the general characters of the 

 reaction, my attention was very naturally directed to the ethylic series. 

 For this purpose, it was first necessary to procure ethylamine in rather 

 considerable quantities. Happily in this case the liberal cooperation, so 

 often experienced, of my friend jNIr. E. C. Nicholson, was again at hand. 

 Interesting himself with a cordialit}^, for which I caimot sufficiently thank 

 him, in the continuation of my researches on the ethylic bases, Mr. 

 Nicholson had placed at my disposal the product of the action of ammonia 

 on iodide of ethyl produced in a single operation performed in one of his 

 great autoclaves on 20 kilcgs, of iodide of ethyl. 



Thanks to the happ}^ alliance between science and industry, which cha- 

 racterizes our times, I was thus enabled to study the transformation of 

 ethylamine under the influence of chloroform on a rather large scale. 



On gradually introducing a mixture of an alcoholic solution of ethyl- 

 amine and chloroform into a retort containing powdered potassic hydrate, a 

 most powerful reaction takes place ; the mixture enters into ebullition, and 

 a liquid distils over, the penetrating odour of which surpasses anything that 

 it is possible to conceive. Besides the odoriferous body the product of the 

 distillation contains ethylamine, chloroform, alcohol, and water, and a con- 

 siderable number of rectifications are required in order to isolate the cyanide 

 of ethyl from this mixture. 



As the substance is rather volatile, the frequently repeated fractional 

 distillations become a most painful operation, and more than once, while I 

 have been engaged in these experiments, my laboratory has been almost 

 inaccessible. Thus with a temperature of 30° I have found it desirable to 



