Juice of hemlock, 1; linseed meal, 4; boiling water, 10.

B.P. Vapor Coninae. Inhalation of Conine. - Juice of hemlock, 1/2 fl. oz.; solution of potash, 1 fl. dr.; distilled water, 1 fl. oz. Put 20 min. of the mixture on a sponge in an inhaler containing hot water.

Conii Fructus, B.P. Hemlock Fruit. - The fruit of Conium maculatum (spotted hemlock), gathered when fully developed, but while still green, and carefully dried.

Fig. 195.   Conium.

Fig. 195. - Conium.

Characters. - About one-eighth of an inch long, broadly ovate compressed laterally; half-fruit with five waved or crenated ridges. Reduced to powder and rubbed with solution of potash, they give out strongly the odour of coniine.

Conium, U.S.P. Hemlock. - The full-grown fruit of Conium maculatum, gathered while yet green.

Characters. - Similar to those of hemlock fruit, B.P.

Composition. - Coniine, a poisonous alkaloid, occurs in hemlock as a yellow, oily liquid, and is separated by distilling the fruit with slightly alkaline water. The fruit contains methyl-coniine in varying proportion, and a small quantity of volatile oil, which does not appear to be poisonous.

Preparations.

B.P.

Dose.

Tinctura Conii.....................................................................................

20-60 min.

U.S.P.

Abstractum Conii.................................................................................

7-8 gr.

Extractum Conii Alcoholicum ............................................................

2 gr.

Extractum Conii Fluidum....................................................................

15 min.

Tinctura Conii .....................................................................................

60 min.

Physiological Action. - The action of conium depends on the alkaloids, coniine and methyl-coniine, which it contains; and as their action differs considerably and the relative quantity of each varies, contradictory results have been obtained by different observers. The symptoms of conium-poisoning are weakness of the legs and staggering gait, passing on to paralysis, which gradually progresses upwards and finally causes death by failure of respiration. The mind remains clear to the last. Coniine paralyses the ends of the motor nerves and of the vagus, like curare, and afterwards paralyses the motor centres in the brain and spinal cord. It causes death by paralysing the respiratory muscles. Death is usually accompanied by convulsions in warm- but not in cold-blooded animals. There is dilatation of the pupil, and ptosis from paralysis of the endings of the third nerve. Locally applied, it appears to paralyse the ends of sensory nerves..

Methyl-coniine acts on the spinal cord, causing paralysis of reflex action.

Dimethyl-coniine and conhydrine have an action similar to that of coniine, but less powerful.

Uses. - It is used locally as a poultice to soothe pain in cancer and ulcers, and as a vapour to relieve cough in bronchitis and pertussis. It is used to allay muscular spasm in chorea, mercurial tremor, and paralysis agitans, but is useless in tetanus and strychnine-poisoning. The best preparation to use is the succus in doses of one drachm, gradually increased as the patient becomes tolerant of the drug.