472 
PHYSIOLOGICAL ACTION AND THERAPEUTICAL USES OF 
To a young horse six ounces of the succus conii were given, but no effect followed till 
the dose had been gradually increased to sixteen ounces, when a set of symptoms came 
on similar to those which are found in man. 
One of the earliest indications of its effect is paralysis of the third nerve, and conse¬ 
quently ptosis, and dilated pupil ; its last effect is complete obliteration of all muscular 
movement derived from the cerebro-spinal motor tract; in many hundred experiments 
no pure cerebral effects have been noticed. 
The lecturer assumed that conia represented the active principle of hemlock in its 
entirety, but whether as conia or some product of its decomposition, he had been unable 
to make out; the urine is unaffected when even powerful doses have been given. Two 
methods were adopted to find this alkaloid in the urine. 
1 . The urea having been precipitated by proto-nitrate of mercury, the clear filtrate 
was allowed to evaporate spontaneously; the syrupy residue was treated with an excess 
of caustic potash and washed with ether; after the distillation of the ether, an oily 
residue remained of a minty odour, but possessing none of the characters of conia. On 
adding caustic potash, the peculiar smell of the drug was evolved; but this seems to be a 
fallacious test, for on treating perfectly normal urine in a similar way, the odour exactly 
resembled the other. 
2 . The urine, after being mixed with a saturated solution of oxalic acid, was allowed 
to evaporate to a brown syrupy residue. On adding an excess of potash, no odour, nor 
any trace of conia could be found, No odour has been noticed in the breath, nor does 
it appear to be eliminated by any of the secretions. 
With regard to its use in disease, great stress was laid on the proposition “ That a 
dose of hemlock, which falls far short of producing its peculiar physiological effects, is 
of no more use than an ordinary dose of quinine in the treatment of ague.” The use of 
inert preparations of conium have rendered almost worthless all previous statements 
with regard to the medicinal value of this plant. 
In tetanus, chorea, epilepsy, spasmodic affections of the stomach or oesophagus, and 
muscular tremor, this drug has produced very valuable effects. 
At the conclusion of the lecture attention was drawn to the value of the various pre¬ 
parations in the British Pharmacopoeia of this drug. Nothing is easier to prove than 
that the extract of conium, with which Storck persuaded himself he cured such a variety 
of diseases, is inert. 
Epitomizing the results, the author observed:—With regard to the dried leaf of hem¬ 
lock, which is still retained in the British, and constitutes the chief basis of the prepa¬ 
rations of conia in the French and other Continental Pharmacopoeias, it is of but little, 
if any, value. After careful and repeated examination of the recently dried and well 
preserved leaf, it was found that 51 'jss—a quantity equivalent to a pint of the tincture 
(P.L.)—does not contain more than a grain of conia at most. Dr. Harley took £ij of it, 
recently prepared, with no other result than slight alcoholic stimulation, and §j has often 
been given without producing any physiological action. The tincture of the fruit, which 
in the B.P. has been substituted for the tincture of the leaf, is alike inert and valueless. 
After using every precaution in the preparation of this tincture, f ^ij of it produced no 
other effects than those which would have resulted from taking an equivalent amount of 
alcohol; these negative results were obtained in many cases. 
After careful examination of recent ext. conii, it was found that the best prepared 
samples only contained 1 per cent, of conia, and that 25 grains of it are equivalent to 
only 3 iv of the succus ; in one case, 250 grains of the extract yielded but 2£ grains of 
pure conia, or rather less than 1 per cent. From 20 to 30 grains of this were given to 
patients, in whom jiv or 5 V of the succus produced very decided symptoms, but without 
any result. 
“ I repeat, therefore, that it is impossible by the process given in the British Pharma¬ 
copoeia, and probably by any other process, to prepare an extract which shall contain 
more than 1 per cent, of conia. This being the case, it will appear obvious that the 
extreme dose recommended in the Pharmacopoeia—viz. 6 grains—is insufficient to pro¬ 
duce medicinal effects in any of the severe cases above mentioned. An ordinary dose of 
this extract for a male adult would be from 30 to 40 grains. The only preparation 
which retains the active principle of the hemlock in sufficient quantity is the succus, 
and this possesses the full activity of the plant, and is a most valuable medicine. 
This drug, in doses varying according to the activity of the individual, from to 8 
