601 
ON THE PREPARATIONS OE CONIUM OE THE BRITISH 
PHARMACOPCEIA, AND THE TINCTURE OE THE LONDON 
PHARMACOPCEIA. 
BY JOHN HARLEY, M.D. LOND., F.L.S., ASSISTANT PHYSICIAN TO KING’s 
COLLEGE HOSPITAL, ETC. 
(Jjontinuedfrom p. 455.) 
In my last communication I gave an account of some experiments with 
two samples of the tincture of the dried leaf. The conclusion to be derived 
from them clearly coincides with that formed of the tincture of the fruit, 
viz. that it is practically an inert preparation. 
As far as a spirituous preparation of the dried leaf is concerned, I think 
my experiments are conclusive. They entirely accord with my previous ex¬ 
perience, which first led me to mistrust the preparation. 
Feeling, however,that it is a matter of considerable importance to determine 
whether the dried plant does retain any active properties, and if so in what 
degree, I have carefully examined the dried leaves, from a portion of which 
the tinctures employed in my experiments were prepared. Excepting in the 
poultice, the dried leaf is no longer used in the British Pharmacopoeia ; but 
the importance of the investigation wdli be recognized when it is observed 
that the dried plant is largely used in some other Pharmacopoeias. Looking 
first to our nearest neighbours, I find that the French Codex contains no less 
than six preparations of the dried leaf, viz.:—1. An alcoholic extract; 2. A 
plaster made of this extract; 3. An injection, composed of an infusion of the 
dried leaf; 4. Powder of the dry leaves ; 5. An sethereal tincture; and lastly, 
6. A tincture. 
The Norwegian Pharmacopoeia has two preparations of conium. 1. The 
dried leaf, prescribed as follows ;—“ medium dose, 2 to 3 grains ; 10 grains 
would be a dangerous dose.” 2. An aqueous extract of the dried leaf treated 
by alcohol, of which it is said :—“ medium dose 1 to 2 grains ; a dangerous 
dose, 6 grains.” 
There is scarcely a Continental Pharmacopoeia which does not contain 
these and similar preparations of conium. 
The ‘ United States Pharmacopoeia ’ contains four preparations of conium, 
three of which are derived from the dried leaf:—1, an alcoholic extract; 
2, a fluid extract; and, 3, a tincture corresponding to that of the London 
Pharmacopoeia. 
It is to be observed that the dried plant is thus extensively used notwith¬ 
standing that some very competent observers have expressed doubts respecting 
its activity. Geiger indeed expressl}'- states* that the dried leaves of hemlock 
do not contain any conia, and Pereira saysf “ no reliance can be placed on the 
dried leaves however carefully prepared, for they sometimes yield no conia, 
though they possess the proper hemlock odour and a fine green colour.” Of 
these two statements the latter is nearer the truth, but it implies—wdiat I 
believe is untrue—that some dried hemlock leaves do possess the active pro¬ 
perties commonly ascribed to them. 
The following are my own observations upon this point:— 
Jdlxaminaiion of the dried leaves used in the preparation of the tincture 
above referred to. 
I. February 11, 1867. Took one ounce avoirdupois of each of the two 
samples of leaves, separated from leaf-stalk and in coarse powder, and packed 
* Magazin fiir Pbarmacie, xxxvL 
f Pereira, Elem. Materia Medica, vol. ii. part ii. p. 195. 
