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II. On the Nitrogenated Principles of Vegetables as the Sources of Artificial Alkaloids. 
By Dr. John Stenhouse, F.R.S. 
Received June 13, — Read June 21, 1849. 
Part I. 
There are few departments in organic chemistry which during the last six or seven 
years have attracted more of the attention of experimenters than the artificial forma- 
tion of the alkaloids. This perhaps is not to be wondered at when we consider the 
interesting nature of this class of bodies, both as regards their well-defined chemical 
properties and the important medical virtues which many of them possess. All 
attempts to form the natural alkaloids, such as quinine, cinchonine, strychnine, &c., 
by artificial means have hitherto been unsuccessful, but chemists have been enabled by 
various processes to procure artificially a considerable number of true alkaloids quite 
analogous to those which occur in nature. Several of these artificial alkaloids, such 
as quinoline, narcogenine, cotarnine, &c., are obtained from the natural alkaloids by 
aeting on them by various reagents. 
A second group, comprising furfurine, thiosinnamine, &c., are formed when ammonia 
is brought in contact with some of the essential oils, such as oil of mustard. 
A third very numerous group, comprising nitraniline, toluidine, cuusedine, &c., 
are obtained by the reducing action of sulphuretted hydrogen or sulphide of ammo- 
nium on nitrogenous compounds formed by treating certain hydrocarbons with nitric 
acid. 
I shall conclude this enumeration by noticing a fourth very important group, com- 
prising aniline, picoline, petenine, &c., which are obtained by the distillation of coal 
or animal substances, as in the case of bone-oil in the preparation of animal charcoal. 
To this last group I shall especially refer in the course of the present notice. 
It is somewhat remarkable therefore, that while so many other sources have been 
examined, no attempt, so far as I am aware, should hitherto have been made to pro- 
cure alkaloids from the highly nitrogenated principles, which under the names of 
vegetable albumen, fibrine, caseine, &c. are found in all plants, in many instances to 
a very considerable amount. These principles are, as is well known, almost as rich 
in nitrogen as the corresponding animal compounds, containing on an average about 
15 per cent, of that element. What also renders the neglect of these substances by 
experiments still more singular, is the consideration that among the known sources 
of the artificial alkaloids coal has been one of the most productive, yielding as it 
does, in addition to ammonia, four other bases, aniline, quinoline, picoline and pyrrol, 
and not improbably containing also other organic bases which have hitherto escaped 
