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XXII. Contributions to the History of the Phosphorus-Bases. 
By Augustus William Hofmann, F.R.S. 
Eeceived June 21, — Bead June 21, 1860. 
riEST MEMOIE. 
In a paper* published a few years ago by M. Cahoues and myself, the remarkable 
phosphorus-compounds, whose existence was first pointed out by the experiments of 
M. Paul Thenaed, were subjected to a more complete examination than they had 
previously received. 
The discovery of a better mode of preparation enabled us to gain a clearer view of 
the nature of this group of substances, and to throw additional light on their relations 
to the nitrogen-bases ; but, owing to the overwhelming number of reactions which pre- 
sented themselves, w^e were unable to submit the behaviour of the phosphorus-bases 
with other groups of bodies to a detailed examination. 
In continuation of former experiments, I have lately been much engaged in the 
investigation of the polyatomic ammonias, the study of which was naturally suggested 
by the beautiful researches which have been published on the polyatomic alcohols. In 
the course of these experiments, I frequently had occasion to return to the phosphorus- 
bases, the employment of triethylphosphine in particular having in many instances led 
to results which would not easily have been obtained in any other way. The possibility 
of preparing this body in a state of perfect purity and in considerable quantity, by a 
series of processes, which, if not quite simple, are at least definite and certain, its posi- 
tion in the system of organic compounds, its conveniently situated boiling-point, the 
energy and precision of its reactions^ and lastly, the simplicity which characterizes these 
reactions, in consequence of the absence of unreplaced hydrogen in triethylphosphine, 
— whereby the formation of a large number of compounds of subordinate theoretical 
interest is excluded, — all these conditions tend strongly to invite us to the study of a 
body, in whose chemical relations the leading questions of the day are not unfrequently 
mirrored with surprising distinctness. 
It was originally my intention to put together — in one frame, as it were — the various 
facts which I have collected relating to the phosphorus-bases; but the material lies 
scattered in so many directions, that I deem it more advisable to publish these observa- 
tions in a number of shorter memoirs, which, from the nature of the subject, must be 
more or less fragmentary. 
* Philosophical Transactions, vol. cxlvii. p. 575. 
3 I 
MDCCCLX. 
