On the natural history, action, and uses of Indian hemp / by Alexander Christison.

Christison, Alex. (Alexander)

Date:: 1851

Credit: On the natural history, action, and uses of Indian hemp / by Alexander Christison. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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$tracts of the sliops generally seem to be. I have repeated Mi- Ro- bertson's process on a small scale with gunjah, and found it to be a very convenient and complete means of rapidly exhausting the plant, while at the same time the consumption of spirit is less than in the process by cold percolation. Good extract thus prepared, like all other good extracts that I have seen, has a dark greenish-black colour, a firm consistence, and great tenacity, a faint peculiar aromatic odour, and a feeble peculiar bitterish taste. It softens in the hand, and adheres with great ob- stinacy to the fingers ; it is not at all miscible with water. It forms a beautiful deep green tincture with rectified spirit, in which it is easily soluble. I have sometimes seen in the shops an extract, which is emulsive, so as to be easily diffused in water, and even rubbed down with the finger. All such must be spurious, and are probably feeble, if not inert. Various investigations have been made as to the nature of the resinoid secretion of the leaves of cannabis; and it has been ascer- tained that a resin can be separated from it, retaining the properties of the plant in full energy. Gastinell, apothecary at Cairo, has pre- pared this substance, of which he says two grains are as effective as six of alcoholic extract. M. de Courtive of Paris says, that the resin prepared by him is, in the dose of three-fourths of a grain, as effective as thirty grains of the butter-extract (extrait jnir, au beurre). He also prepared the resin from Paris-grown Indian hemp, and from French hemp, and he found that six grains of the first, and eight to sixteen of the second, were necessary to produce the effect \_Co)nptes Bendiis de rinstitut, 1848, p. 509]. I have found one, two, or three grains of Mr Robertson's alcoholic extract equal in activity to three-fourths of a grain of the resin. The Messrs Smith of Edinburgh have succeeded in concentrating the properties of the extract in a soft neutral resin, which the}'- are disposed to regard as its active principle, and have denominated Cannabin [Fharm. Journal, 1846-47, p. 171]. The essential part of their process, which is somewhat complex, consists in removing from gunjah whatever is soluble in warm water, and in a cold solu- tion of carbonate of soda, and then preparing from the residuum an alcoholic extract with rectified spirit. In this way colouring matter, fat, and chlorophyle, are in part removed. The rest of the process, by which it is proposed to purify the resin still farther, by the suc- cessive use of milk of lime, sulphuric acid, animal charcoal, and water, has not appeared to me to make any material difference in the preparation. The Messrs Smith got seven or eight per cent of this resin from gunjah, which is just what Mr Robertson obtained of alcohoHc ex- ?ract. From Dr O'Shaughnessy's gunjah I obtained fully ten per cent. The numerical results were, from'3840 grains. 500 of watery extract, 040 alkaline extract, 2310 fibrous residue, and 390 purified$

On the natural history, action, and uses of Indian hemp / by Alexander Christison.

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