Mr. Leschenault having brought home a small quantity of this poison, it was tried by Messrs. Delile and Magendie in several experiments, when it was found to act more or less violently, according to the age and size of the individual, or the quantity of the upas. One grain and a half inoculated in a young dog killed it in four minutes, only producing one convulsive fit. In a dog weighing fourteen pounds, half a grain of upas occasioned death at the expiration of one hour and fifty-seven minutes, during which the animal experienced several violent convulsions. A few drops of diluted upas, injected in the chest of a dog, weighing twenty pounds, occasioned a lock-jaw, which destroyed him in a minute and a half. Eight drops injected in the jugular vein of a horse produced immediate tetanus and speedy death. For further information regarding these cruel experiments we must refer to the experimenter’s publication. It appears, however, that the power of this venomous substance is so intense that time does not weaken it; for the upas employed in these experiments had been collected and kept for upwards of seven years, when its effects were as prompt as when tried in a recent state. The natives of Java consider sea-salt as the best antidote, but Mr. Delile found it quite inert: various experiments induced him to think that in these cases death is produced by asphyxia; and he considers the means employed to restore suspended animation in persons supposed to have been drowned, as the most likely to save the life of individuals who might be wounded with this substance. The rapidity with which poisonous substances are absorbed in the system is truly terrific, more especially in such as are of a narcotic nature. The latter act by abolishing all nervous energies, but when applied locally their effects are also local, as is shown by the following experiments of Müller:
“I held the nerve of a frog’s leg which was separated from the body, in a watery solution of opium for a short time, and that portion of the nerve lost its irritability, i.e. its property of exciting twitchings of the leg when it was irritated; but below the part that the poison had touched the nerve still retained this function.”
It is therefore evident that before narcotic poisons can exert a general influence they must be carried into the circulation. Duprey and Brachet, two French physiologists, have sought to prove that animals cannot be destroyed by narcotic poisons, introduced in the stomach, if the nervus vagus has been divided on both sides; at least, that they do not die so soon. However, Wernscheidt, in thirty experiments on mammalia, could not perceive this difference, provided the animals were of the same size and species.
Prussic acid exerts its influence so rapidly that it cannot be supposed to have been thrown into the circulation. The spirituous solution of the extract of nux vomica introduced in the mouth of a rabbit, produces immediate death, whereas when applied to any nerve distant from the brain it produces no general symptoms.
This rapid effect of prussic acid is supposed to arise from its great volatility and powers of expansion, by which it is diffused more quickly through the circulation than the blood. According to Schrader one drop of this substance introduced in the bill of a bird killed it in four or five minutes. Hydrocyanic acid gas mixed with atmospheric air has when inhaled destroyed dogs, cats, rabbits, and various birds, in from two to ten seconds. Magendie found that the introduction of one drop of the acid in the jugular vein caused instantaneous death; a glass tube dipped in this perilous substance applied to the tongue of a dog, produced a similar effect, which was also the result when applied to the eye.
It is not generally known that tobacco and its preparations are deadly poisons, one drop of oil of tobacco introduced in the mouth of a dog produced violent convulsions with hurried breathing; a quarter of an hour after, the unfortunate animal seemed to be recovered, when the introduction of another drop killed it in two minutes. M’Cartney and Orfila obtained similar results, though no such effects were produced when it was applied to a nerve or the surface of the brain.
The French poet Santeuil died from having drank wine in a glass containing some snuff. In all cases of death produced by this substance the lungs are found dense and livid.
It is not only in the upas that the Indians seek the means of poisoning their missiles. In America they employ the Ticronas a juice extracted from various plants, and the preparation of which, transmitted from one generation to another is considered a valuable secret. La Condamine asserts that its mere odour is sufficient to destroy the criminals doomed to smell it, but Fontana has found by many experiments that this assertion was made upon report, which travellers too frequently rely upon to save themselves the trouble of investigation. Arrows saturated with this poison, become more active after having been dipped in hot water.
The Indians of Guiana dip their arrows in the juice of the Woorara, and the Curara, which also occasions rapid death and decomposition of the lungs. Humboldt informs us that the Curara is obtained from the bark of a tree called Vejuco de Mavacure; it is inspissated over a slow fire and then mixed with a gum drawn from the Kiracagnero. The Abbé Salvador Gilii tells us in his history of America, that he has seen the strongest animals succumb instantly when thus wounded, but the poison does not produce any effect on their meat.