Extractum Cannabis.-Take of the dried flowering tops, rejecting the steins, any quantity; rectified spirit, a sufficiency; boil the tops in the spirit until all the resin is dissolved out ; distil off the spirit with the heat of a vapour bath, so as to obtain an extract of a proper consistence. Dose : Ten to twelve grains, gradually increased until a tendency to coma is produced, half a grain to a grain and a half is the dose usually given in the East, and this quantity frequently produces marked effects there. It is best given in the form of a pill.
Tinctum Cannabis (O’Shaughnessy). Extract of Indian hemp, three grains ; proof spirit, one fluid drachm; dissolve. Dose: One to two fluid drachms, frequently repeated, until the desired effect is produced. This tincture is decomposed by water, the resin being precipitated in the form of a pale yellow powder. It should, therefore, be suspended in aqueous vehicles, by means of mucilage, syrup, or yolk of egg. – Dr. Neligan.