Cannabis sativa, grown in the Southern United States and collected while flowering.

Characters. - Stem about six feet (2 metres) long, rough; leaves opposite below, alternate above, petiolate, digitate; the leaflets linear-lanceolate, serrate; dioecious, the staminate flowers in pedunculate clusters forming compound racemes; the pistillate flowers axillary, sessile, and bracteate; odour heavy; taste bitter, slightly acrid.

Composition. - The active constituent is a resinoid substance, cannabin. The tops also contain a small quantity of volatile oil.

Action. - Its chief effect is on the brain, and is of a twofold nature; it excites a form of delirium and hallucinations, usually followed by deep sleep.

Small doses give rise to delirium with hallucinations, generally of a gay character, causing much merriment; accompanied by a great inclination to muscular movement.

The nature of the hallucinations depends greatly on the character of the individual, and people seem to be able to determine their nature, as in the case of opium.

Haschish is an Arabian preparation of Indian hemp, and is the origin of the word assassin. An Eastern chief used to dose his fanatic followers with Indian hemp, and they became imbued with the idea that they would be taken to heaven if killed, and hence were not afraid to encounter death.

The dreams produced by Indian hemp in inhabitants of Eastern countries are usually of a sexual character (p. 450), but when taken by the more civilised people of Western nations they are not sexual, and are often of a disagreeable nature.

During this stage of hallucination, the person may conduct himself rationally and answer clearly any question put to him (Wood). The drug produces in some persons a curious loss of sense of time and of space. This stage is generally followed by deep sleep. The sensory nerves are benumbed, and there is frequently tingling and partial anaesthesia. The pupil is dilated.

Respiration may be either quickened or slowed. The action on the pulse is very uncertain. Usually it is first quickened, then slowed, sometimes vice versa. The temperature rises or sinks according as the drug produces muscular movement or sleep. The urine is increased. The processes of digestion are less altered by cannabis indica than by opium, and the aftereffects of opium (nausea, headache, etc.) are not produced.

Uses. - As a soporific it is used instead of opium when the latter does not agree, or in old opium-eaters; also in cases of mental derangement; in acute and chronic mania it is very useful, especially when combined with potassium bromide.

It has been used in neuralgia to lessen pain; also in spasmodic coughs, asthma, etc. In certain cases of menorrhagia it is useful, but its mode of action is unknown. Ringer recommends it in migraine, and S. Mackenzie in constant headache.