This substance appears to be an extract from a species of Strychnos mixed with some mucilaginous juice.

Characters. - A black extractiform body some specimens of which are readily soluble in water, but others leave an insoluble residue.

Composition. - It contains an alkaloid, curarine.

Action. - It paralyses the peripheral ends of motor nerves even when given in very minute doses (p. 147). Larger doses paralyse the vagus and the ends of sensory nerves. As poisoning progresses the spinal cord is paralysed, and finally the heart. Voluntary muscles appear to be little affected, yet their contractility is somewhat diminished, and this diminution begins even before the motor nerves themselves are paralysed. The vessels of the surface become dilated, and sometimes a peculiar erythematous rash appears on the skin in dogs. The blood-pressure is little affected by small doses, but is much lowered by large ones. When injected into the salivary gland it causes intense salivation, which appears to be paralytic (p. 355). In men who have been slightly poisoned by it, it has produced increased secretion of the sweat, tears, nasal mucus, saliva, and urine, with a feeling of weariness and disinclination to move. Large doses produce death by paralysis of the muscles of respiration, but, the motor nerves of the extremities being paralysed, no convulsions occur. Although the motor nerves are paralysed to such an extent that they will not excite muscular contractions, even when the nerve-centres are powerfully stimulated by asphyxial blood, they still cause muscular contractions when irritated by an interrupted current in a warm-blooded animal poisoned by curare. In frogs the poisoning may be so complete that no irritation of the trunk of a nerve will excite contraction in the muscles supplied by it. Curare is rapidly eliminated by the kidneys, and if artificial respiration be kept up complete recovery occurs. I have succeeded in restoring an animal completely by this means, after it had been apparently dead for four hours. When given internally, curare is so rapidly eliminated that it usually produces no symptoms. When given in a very large dose on an empty stomach, symptoms of poisoning may occur. If elimination be prevented, by excision of the kidneys or ligature of the renal vessels, poisoning occurs, and in this case death is usually preceded by convulsions. So rapidly does elimination occur, that the urine of a frog poisoned by curare will paralyse a second frog injected subcutaneously, and the urine of the second will even paralyse a third.

Uses. It has been employed, but without much benefit, in epilepsy and chorea, and has been used with success in traumatic tetanus. In poisoning by strychnine it is not so useful as chloral. A case of hydrophobia has been described by Offenburg in which the subcutaneous injection of curare, to such an extent as to keep the patient almost, though not quite, paralysed for some time, effected a cure. If this were really so it would be most important, but from a comparison of the symptoms described by Offenburg with those of three fatal cases I have myself seen, I am inclined to think that his case was one of hysteria mimicking hydrophobia.