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XIV. Researches into the Molecular Constitution of the Organic Bases. 
By Dr. A. W. Hofmann, F.C.S., Professor of the Royal College of Chemistry of London. 
{Second Memoir.) Communicated hy Sir James Clark, Bart., F.R.S. 
Received March 12, — Read April 3, 1851. 
About twelve months ago I had the honour of presenting to the Royal Society an 
account of a series of researches into the molecular constitution of the volatile organic 
bases*: at present I beg to submit to the consideration of the Society the history 
of a new group of alkaloids, which, although intimately connected with the former 
by their origin, differ from them altogether by their properties, and especially in not 
being volatile. 
The members of this new group of alkaloids are so numerous, their deportment is 
so singular, and their derivatives ramify in so many directions, that I have not as 
yet been able to complete the study of these substances in all their bearings ; nor is 
it my intention to go fully into the chemistry of the subject in the present com- 
munication, my object being merely to establish the existence of these bodies, and 
to give a general outline of their connection with the volatile bases, and of their most 
prominent chemical and physical properties, reserving a detailed description of their 
salts and derivatives to a future memoir. 
In the paper above referred to, I advanced the position that the majority of the 
volatile organic bases might be represented by the general expression 
X 
Y 
Z 
N, 
a formula which coincides with that of ammonia, if X=Y=Z=H. I proved by ex- 
periment that the terms X, Y and Z may represent, not only hydrogen, but a variety 
of hydrocarbons, especially the so-called alcohol-radicals (C„ and endeavoured, 
on the ground of these experiments, to classify the volatile organic bases according 
to the amount of basic-f- hydrogen retained in the several alkaloids. I thus arrived 
at three groups of bases, for which, in accordance with traditional names, I proposed 
the terms amidogen-bases, imidogen-bases and nitrile-bases. 
The ideas enunciated regarding the constitution of the volatile organic bases, were, 
it is true, to a certain extent, the result of theoretical speculation ; but they were so 
* Philosophical Transactions, Part I. 1850, p. 93. f Ibid. p. 111. 
3 A 
MDCCCLI. 
