Strychnia was discovered by Pelletier and Caventou soon after the discovery of morphia.[[2324]] For an account of the best process for preparing it, the reader may consult a paper by M. Henry in the journal quoted below.[[2325]]
Its leading properties are the following. Its crystals when pure are elongated octaedres. It has a most intensely bitter taste, perceptible, it is said, when a grain is dissolved in 80 pounds of water.[[2326]] It is very sparingly soluble in water, but easily soluble in alcohol and the volatile oils. Its alcoholic solution has an alkaline reaction. It forms neutral and crystallizable salts with the acids. In its ordinary form it is turned orange-red by the action of nitric acid; which tint becomes violet-blue on the gradual addition of hydrosulphate of ammonia. The action of nitric acid is owing to the presence of a yellow colouring matter, or of another alkaloid, brucia, which is also contained in nux vomica, but exists in larger quantity in the false angustura bark. Pure strychnia is not turned orange-red by nitric acid.[[2327]]
No poison is endowed with more destructive energy than strychnia. I have killed a dog in two minutes with a sixth part of a grain injected in the form of alcoholic solution into the chest; I have seen a wild-boar killed in the same manner with the third of a grain in ten minutes; and there is little doubt that half a grain thrust into a wound might kill a man in less than a quarter of an hour. It acts in whatever way it is introduced into the system, but most energetically when injected into a vein. The symptoms produced are very uniform and striking. The animal becomes agitated and trembles, and is then seized with stiffness and starting of the limbs. These symptoms increase till at length it is attacked with a fit of violent general spasm, in which the head is bent back, the spine stiffened, the limbs extended and rigid, and the respiration checked by the fixing of the chest. The fit is then succeeded by an interval of calm, during which the senses are quite entire or unnaturally acute. But another paroxysm soon sets in, and then another and another, till at length a fit takes place more violent than any before it; and the animal perishes suffocated. The first symptoms appear in 60 or 90 seconds, when the poison is applied to a wound. When it is injected into the pleura, I have known them begin in 45 seconds, and Pelletier and Caventou have seen them begin in 15 seconds.[[2328]] M. Bouillaud has recently found that it has no effect when directly applied to the nerves.[[2329]] The experiments of Mr. Blake tend to show, that its action is exerted solely on the nervous system, and that it has no direct action on the heart, even when directly admitted into the blood by the jugular vein.[[2330]] It appears to act peculiarly by irritating the spinal cord.
Dangerous effects have often been occasioned by an accidental over-dose in ordinary medical practice. These are well exemplified by a case communicated to Dr. Bardsley by Dr. Booth of Birmingham. A man of 46, affected with hemiplegia for nearly four weeks, began to use strychnia, and had been affected by it for eleven days without particular inconvenience. During this period he took twice a day gradually increasing doses, till the amount of one grain was attained; when the usual physiological effect having ceased to occur, the quantity was increased to a grain and a half. But the first dose caused anxiety and excitability, in three hours stupor and loss of speech, and at length violent tetanic convulsions, which proved fatal in three hours and three-quarters.[[2331]] A fatal case, occasioned by the large dose of two scruples, has been recorded by a German physician, Dr. Blumhardt. In fifteen minutes, imperfect vomiting was brought on by emetics. At this time, the patient, a lad of seventeen, lay on his back, quite stiff, and with incipient fits of locked-jaw. The spasms gradually extended to the rest of the body, till at last violent fits of general tetanus were established, under which the whole body became as stiff as a board, the arms spasmodically crossed over the chest, the legs extended, the feet bent, so that the soles were concave, the breathing arrested, the eyeballs prominent, the pupils dilated and not contractile, and the pulse hurried and irregular. In the second severe fit he died, one hour and a half after taking the poison.[[2332]] I have known very dangerous tetanic spasm induced by so small a dose as two-thirds of a grain of the ordinary impure strychnia of the shops; and Dr. Pereira describes a case, communicated by a friend, where death was occasioned by a dose of half a grain administered three times a day.[[2333]] As each fit of spasm went off, respiration, which was found to have ceased, was maintained artificially; but no sooner did natural breathing return, than the paroxysm of tetanus returned also; and at length artificial inflation of the lungs failed to restore life.
The only accounts I have seen of the morbid appearances after death from strychnia are in the cases of Dr. Booth and Dr. Blumhardt. In the former, the muscles were in a rigid state, the fingers contracted, the vessels of the brain gorged, the membranes of the spinal cord highly injected; and four patches of extravasated blood were found between the spinal arachnoid and the external membrane. In the latter, twenty-four hours after death, there was general lividity of the skin, and extraordinary rigidity of the muscles. Fluid blood flowed in abundance from the spinal cavity, where the veins were gorged, the pia mater injected, the spinal column softened at its upper part, and here and there almost pulpy. There was also congestion and softening of the brain. The head and great vessels were flaccid, and contained scarcely any blood. The inner membrane of the stomach and intestines presented some redness, but not more than is often seen independently of irritation there.
Strychnia has been found by Pelletier and Caventou in four species of Strychnos, the S. nux vomica, Sancti Ignatii, Colubrina, and Tieuté; and from the researches of MM. Martius and Herberger on the composition and properties of the American poison Wourali, it is also probably contained in the S. guianensis.[[2334]] Vauquelin could not find it in the S. pseudo-kina, which is destitute of bitterness.
Of Poisoning with Nux Vomica.
Tests of Nux Vomica.—Nux vomica, the most common of these poisons, is a flat, roundish seed, hardly an inch in diameter, of a yellowish or greenish-brown colour, covered with short silky hair, and presenting a little prominence on the middle of one of its surfaces. In powder it has a dirty greenish-gray colour, an intensely bitter taste, and an odour like powder of liquorice. It inflames on burning charcoal, and when treated with nitric acid acquires an orange-red colour, which is destroyed by the addition of protochloride of tin. Its infusion also is turned orange-red by nitric acid, and precipitated grayish-white with tincture of galls.
Orfila and Barruel have made some experiments on the mode of detecting it in the stomach, and the following is the plan recommended by them. The contents of the stomach, or the powder, if it can be separated, must be boiled in water acidulated with sulphuric acid. The liquid after filtration is neutralized with carbonate of lime, and then evaporated to dryness. The dry mass is then acted on with successive portions of alcohol, and evaporated to the consistence of a thin syrup. The product has an intensely bitter taste, yields a precipitate with ammonia, becomes deep orange-red with nitric acid, and will sometimes deposit crystals of strychnia on standing two or three days.[[2335]] By this process Dr. R. D. Thomson, in a case which proved fatal in three hours, detected nux-vomica, although vomiting had been induced by emetics.[[2336]]
These experiments it is important to remember, because, contrary to what takes place in regard to vegetable poisons generally, nux vomica is often found in the stomachs of those poisoned with it.