most direct poison to the nervous system acts quickest when introduced into the circulation by an external wound; and many of the very poisons which destroy the nervous energy most suddenly when applied to a particular nerve, produce no bad effects. To one who fooks on the nerves as the circulating medium of a volatile elastic fluid, such as the nervous energy is described by Mead, it will be difficult to understand the possibility of the most powerful poisons being applied to nerves without any ill effects. But may we not look upon the nervous system as the apparatus for the the transmission and direction of the vital energy, or aura, which is the principle of life,-the sanguineous system as the source of its elimination,-and when a virulent poison has been introduced into it, understand why its influence is generally exerted on the nervous system long before it is exerted on the heart? Celsus says that venomous bites kill by extinguishing the vital heat. It is not by coagulating the blood, or, indeed, by any specific action on the blood that is cognizable to us, that many of the most powerful poisons produce death. The woorara produces its effects on the brain, and not the heart; the upas, it is supposed by Orfila, on the spinal column. The ticunas, a very active poison of the Indians, made from the juices of various withes. or lianes, evaporated to a thick consistence, when introduced into the jugular vein of a dog, kills on the spot, and, unlike the venom of the viper, does not coagulate the blood.

The curare, we are told by Humboldt, is prepared from a withe called vejuco de mavacure, with which the Indians poison their arrows; it kills the largest animals very speedily, and acts on the circulation. It is certain that the flesh of the animals killed by this very active poison is nowise impaired by it. Humboldt remarks, "it seems all the poisons come from the withes."

Raynal makes a similar observation. The creeping plants (he says) called lianes, of which there are vast VOL. II.

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numbers in all tropical woodlands, furnished the poison which was in universal request on the continent. The immediate death that arises from this poison, he thinks, so far from coagulating the blood, when mixed with that fluid recently drawn and warm, prevents coagulation, and even, for some time, putrefaction. There is one species of poison arising from decomposition of animal matter, the intensity of whose virus in tropical climates is very little known. Some experiments have been made in Europe, mentioned by Orfila, of putrescent blood having been applied to an abraded surface; one producing death in twenty-six hours; another in eighteen; and of bile in a state of decomposition, being applied to a wound, and death occurring in twenty hours; which event, he says, does not depend on local irritation, or even of its action on the circulating sys

tem.

In hot climates, the concentrated poison of putrescent animal matter, I suspect, produces death much more speedily than Orfila states here; and its effects seem to be similar to those of asphyxia, such as came under the care of Dupuytren, in three instances, arising from only inhaling the vapour of decomposed animal matter, or sulphureted hydrogen gas.

I stated, in my Eastern Travels, I had been informed by an Arab barber who practised physic, that one of the most deadly poisons was prepared from the mucous membrane of the intestines, taken from the putrid body; and had also been told by Lady Hester Stanhope, that the Arabs made use of several poisons unknown in Europe, the deadliest of which was that extracted from the intestines of a murdered man. I was not a little surprised, very lately, to find that the knowledge of this active poison from the dead human body, known to the Arabs, and whose existence I have heard denied in Europe, was known to the native Indians of the West India Islands, and is described by Garcilasco de la Vega, in his History of the civil Wars of the Spaniards in the Indies, vol. i. chapter 42.

He observes, that all the Indians in the Windward Islands poison their arrows by dipping their points into dead bodies. "I shall relate," he continues, "what I have seen happen from one of the quarters of Carjaval, which had been placed on the road of Collasuyn, which is to the south of Cusco. A party of us went one Sunday to take a walk: we were ten or twelve scholars, all mestifs-that is, the sons of Spaniards and Indians, the eldest of which was not twelve years old. Having perceived in the fields one of the quarters of the body of Carjaval, we took it into our heads to go and take a look at it; and having approached it, we found that it was one of his thighs, the fat of which had run on the ground; the flesh was of a greenish colour, and quite corrupted. As we were looking at this horrible object, one of the most hardy of us said, 'I'll wager that there is no one here dare touch it! Another said, 'There is! At last, one of the most daring of all, named Bartheline Monedero, thinking to perform an act of great courage, thrust the thumb of his right hand into the corrupted thigh. This action astonished us all so much, that we left him, fearing to be infected, crying out, Oh, the filthy fellow! Carjaval will make thee suffer for this insolence!' However, he went straight to a rivulet, which was quite near, where he washed his hand several times, and rubbed it with mud, and went home. The next day he came to school, where he showed his thumb, which was extremely swelled; but in the evening all his hand, up to the wrist, was swollen; and the day after, which was Tuesday, the swelling had reached up to the elbow, in such a manner, that necessity compelled him to acquaint his father with the cause of it. Medical assistance was called in; the arm was tightly bandaged, and every kind of remedy was made use of, which was considered would act as a counter-poison. After all this, the patient was very near losing his life; and it was with great difficulty that he escaped, after being four entire months without being able to use his pen, so weak the arm was."

When I was living in Liguanea, where the difficulty of getting fresh provisions was very great, some meat was one day set before us at dinner which was tainted, or, what would be called in England, rather high. About ten o'clock at night, myself, a lady, and Captain Mason, who was then residing with me, were attacked with symptoms of cholera; Captain Mason slightly, but the lady and myself with great depression, cold extremities, and palpitations of the heart. Hot brandy and water relieved these symptoms; but it was several days before two of the party perfectly recovered. I knew of an instance in the neighbourhood of Kingston, where a whole family suffered most severely from the poisonous effects of tainted meat, two of the persons having very nearly died. If climate is capable of giving the character of a poison to the putrefaction of animal matter, one can understand the virulence that diseases acquire in hot climates, which are comparatively mild in cold ones.

The action of those powerful poisons, whether vegetable or animal, which suddenly destroy life, are very similar, in their effects, to the influence of those malign diseases, such as plague, cholera, and yellow fever, which at the first seizure prostrate the nervous energy, and produce the same sudden depression of the vital powers.

The venom of poisonous reptiles seems to be wholly similar to that of plants. Fontana, who made upwards of 6000 experiments on venomous reptiles, states the venom of the viper applied to a nerve is harmless as water; from which he concludes its action is on the blood, which it coagulates, and gives a tendency to putrescence. He found the venom of the viper not fatal to its own tribe, or to eels or lizards. By the experiments he made on animals, he estimates the quantity sufficient to kill a man at three grains, and twelve to kill a bullock. In the experiments he made, death ensued at seventeen hours, at eighteen, and at the expiration of three days. Dr. Mosely thinks "the same effects are produced by all the tribe of deadly venomous

serpents; and that there is no specific difference between them, except in the violence and rapidity by which the poison is diffused through the body; the rest depending on the state of the weather and habit of body of the subject at that particular time."

By Mangili's experiments it has been ascertained that the venom of serpents, taken internally, produced no bad effects: his assistant swallowed the venom of four vipers without any inconvenience: a crow was given, mixed with some food, the venom extracted from sixteen vipers, without any effect; yet the dried venom that he had kept for twenty-six months, when put on the inside of the claws of pigeons, produced death, in all, from half an hour to an hour.

The opinion of Celsus that "venomous bites kill by extinguishing vital heat," or, as more recent authors might express it, (though perhaps not more intelligibly,) by depressing the nervous energy, appears to be borne out by the treatment that has been successfully adopted in various parts of the world.

Russell relates that an Indian was bitten by a cobra di capello in the foot: in fifteen minutes his jaws were rigid; he was apparently dead. On eau de luce being applied to the wounds, he rallied a little; and he was made to swallow two bottles of wine of Madeira made hot, by means of a funnel introduced into his mouth. The man recovered. Orfila calls wine, in similar cases, "un remède héroique comme dans beaucoup d'autres circonstances analogues." He does not say what these analogous circumstances are, but I think it is evident he alludes to those diseases in which some miasma of a poisonous nature is received into the circulation, as specific in its character as the venom of the serpent, and whose immediate effects are a sudden depression of the vital powers, exhaustion, and death. A case of envenomed bite, by a serpent, was treated by Mr. Brodie and Sir E. Home in St. George's Hospital, some years ago, by very large doses of spirits of aromatic ammonia, and other powerful stimulants fre