CHAPTER XXXVII.

OF POISONING WITH STRYCHNIA, NUX VOMICA, AND FALSE ANGUSTURA. The next group of the narcotico-acrids includes a few vegetable poisons that act in a very peculiar manner. They induce violent spasms, exactly like tetanus, and cause death during a fit, probably by suspending the respiration. But they do not impair the sensibility. During the intervals of the fits the sensibility is on the contrary heightened, and the faculties are acute. Death, however, does not always take place by tetanus. In some cases the departure of the convulsions has been followed by a fatal state of general and indescribable exhaustion. Besides thus acting violently on the nervous system, they also possess local irritant properties; but these are seldom observed on account of the deadliness and quickness of their remote operation on the spine and nerves. They exert their action by entering the blood-vessels. The dose required to prove fatal is exceedingly small. The organ acted on is chiefly the spinal cord; but sometimes they seem also to act on the heart. They seldom leave any morbid appearances in the dead body. Like the other causes of death by obstructed respiration, such as drowning and strangling, they produce venous congestion; but this is frequently inconsiderable. Sometimes, however, they leave signs of inflammation in the alimentary canal. Their energy resides in peculiar alkaloids. The only poisons included in this group, are derived from the genus _Strychnos_. The bark of _Brucea antidysenterica_ was long supposed also to possess similar properties; but it is now known that the bark of _Strychnos nux-vomica_ was mistaken for the bark of that tree. Several species of _Strychnos_ have been examined, namely, the _S. Nux-vomica_, the _S. Sancti Ignatii_ or St. Ignatius bean, the _S. colubrina_, or snake-wood, the _S. tieuté_, which yields an Indian poison the Upas tieuté, the _S. Guianensis_, and likewise the _S. potatorum_ and _Pseudo-kina_; and all have been found to possess the same remarkable properties, except the last two, which are inert. All of them, except the _S. pseudo-kina_, and probably the _S. potatorum_,[2323] contain an alkaloid to which their poisonous properties are owing. This is _strychnia_ or strychnin, a substance which has lately been made the subject of many experiments by chemists and physiologists. _Of Poisoning with Strychnia._ 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. _Its Mode of Action and Symptoms in Man._—The poisonous properties of nux vomica are now well known to the vulgar; and in consequence it is occasionally made the instrument of voluntary death, although no poison causes such torture. It is difficult to conceive, considering its intensely bitter taste, how any one could make it the instrument of murder. But a fact is stated in Rust’s Journal, which shows that it may be used for that purpose. At a drinking party one man wagered with another, that if he took a little _Cocculus indicus_ in beer, he would be compelled to walk home on his head. The wager was taken and the potion drunk; but nux vomica was substituted for the Cocculus indicus, itself too a virulent poison; and the man went home and died in convulsions fifteen minutes afterwards.[2337] Many experiments have been made on animals with nux vomica; but the first accurate inquiry was that of Magendie and Delille read before the French Institute in 1809. The symptoms they remarked were precisely the same with those produced by strychnia. Half a drachm of the powder killed a dog in forty-five minutes, and a grain and a half of the alcoholic extract thrust into a wound killed another in seven minutes. The animals uniformly experienced dreadful fits of tetanic spasm, with intervals of relaxation and sensibility, and were carried off during a paroxysm. The cause of death appears to be prolonged spasm of the thoracic muscles of respiration. The spasm of these muscles is apparent in the unavailing efforts which the animals make to inspire. The external muscles of the chest may be felt during the fits as hard almost as bone; and, according to an experiment of Wepfer, the diaphragm partakes in the spasm of the external muscles.[2338] On account of the singular symptoms of irritation of the spinal cord, uncombined with any injury of the brain, this poison is believed to act on the spinal marrow alone. This is farther shown by the experiments of Mr. Blake with strychnia alluded to above. But from some experiments by Segalas it appears also to exhaust the irritability of the heart: for in animals he found that organ could not be stimulated to contract after death, and life could not be prolonged by artificial breathing.[2339] A similar observation was made long ago by Wepfer, who found the heart motionless and distended with arterial blood in its left cavities;[2340] and a case of poisoning in the human subject to the same effect will be presently related. The pulse is always very weak, often wholly suppressed during a paroxysm; and in the case alluded to it was found on dissection pale, flaccid and empty, having been apparently affected with spasm. The action exerted through the medium of the spinal cord on the muscles is wholly independent of the brain; for Stannius found that in frogs the removal of the brain does not interfere with the effects.[2341] Of late poisoning with nux vomica has been common. The most characteristic example yet published is a case related by Mr. Ollier, of a young woman, who in a fit of melancholy, took between two and three drachms of the powder in water. When the surgeon first saw her, half an hour afterwards, she was quite well. But going away in search of an emetic, and returning in ten minutes, he found her in a state of great alarm, with the limbs extended and separated, and the pulse faint and quick. She then had a slight and transient convulsion succeeded by much agitation and anxiety. In a few minutes she had another, and not long afterwards a third, each about two minutes in duration. During these fits, “the whole body was stiffened and straightened, the legs pushed out and forced wide apart; no pulse or breathing could be perceived; the face and hands were livid, and the muscles of the former violently convulsed.” In the short intervals between the fits she was quite sensible, had a feeble rapid pulse, complained of sickness with great thirst, and perspired freely. “A fourth and most violent fit soon succeeded, in which the whole body was extended to the utmost from head to foot. From this she never recovered: she seemed to fall into a state of asphyxia, relaxed her grasp, and dropped her hands on her knees. Her brows, however, remained contracted, her lips drawn apart, salivary foam issued from the corners of the mouth, and the expression of the countenance was altogether most horrific.” She died an hour after swallowing the poison.[2342]—A case precisely similar, produced by three pence worth of the powder, and fatal in little more than an hour, is related by Mr. Watt of Glasgow.[2343]—Another apparently also similar but fatal in three hours, is related by Dr. R. D. Thomson.[2344] There is in fact very little variety of symptoms in different cases, where death occurs in the primary stage.—Occasionally even in such rapid cases there is a little vomiting in the first instance. This was remarked in Mr. Watt’s case, and also in another described by MM. Orfila and Ollivier.[2345] When death does not take place thus suddenly in a fit of spasm, the person continues to be affected for twelve or sixteen hours with similar, but milder paroxysms; and afterwards he may either recover without farther symptoms, or expire in a short time apparently from exhaustion, or suffer an attack of inflammation of the stomach and intestines, which may or may not prove fatal. M. Jules Cloquet has described a case, where the patient seemed to die of the excessive exhaustion produced by the violent, long continued spasms. The tetanic fits lasted about twenty-four hours, the sensibility in the intervals being acute. Slight signs of irritation in the stomach succeeded; and death ensued on the fourth morning.[2346] In the Bulletins of the Medical Society of Emulation another case is related, which arose from an over-dose of the alcoholic extract being taken by an old woman who was using it for palsy. She took three grains at once. Violent tetanus was soon produced; and afterwards she had a regular attack of inflammation of the stomach and intestines, which proved fatal in three days. The last instance to be noticed exemplifies very well the effects of the poison when the quantity is insufficient to cause death. A young woman swallowed purposely a drachm mixed in a glass of wine. In fifteen minutes she was seized with pain and heat in the stomach, burning in the gullet, a sense of rending and weariness in the limbs succeeded by stiffness of the joints, convulsive tremors, tottering in her gait, and at length violent and frequent fits of tetanus. Milk given after the tetanus began excited vomiting. She was farther affected with redness of the gums, inflammation of the tongue, burning thirst, and pain in the stomach. The pulse also became quick, and the skin hot. Next day, though the fits had ceased, the muscles were very sore, especially on motion. The tongue and palate were inflamed, and there was thirst, pain in the stomach, vomiting, colic and diarrhœa. These symptoms, however, abated, and on the fourth day disappeared, leaving her exceedingly weak.[2347] This and the previous case show clearly the double narcotico-acrid properties of the poison. With regard to the dose requisite to prove fatal, the smallest fatal dose of the alcoholic extract yet recorded is three grains, which was the quantity taken in the case from the Parisian bulletins: Hoffmann mentions a fatal case caused by two fifteen grain doses of the powder;[2348] and in Hufeland’s Journal there is another caused by two drachms, which was fatal in two hours.[2349]—A dog has been killed by eight grains of the powder, and a cat by five.[2350] It is even said that a dog has been killed by two grains.[2351] It has been thought, from some observations by Mr. Baker on the medicinal use of nux vomica in Hindostan that, by the force of habit, the constitution may become to a certain extent accustomed to large doses of this poison, in the same manner as it acquires the power of enduring large doses of opium. The natives of Hindostan, often take it morning and evening for many months continuously, beginning with an eighth part of a nut, and gradually increasing the dose to an entire nut, or about twenty grains. If it is taken either immediately before or after meals, it never occasions any unpleasant effects; but if this precaution be neglected, spasms are apt to ensue.[2352] As it is found unsafe, however, to increase the dose beyond one nut, and the poison is taken in the form of coarse powder, in which state it must be slowly acted on by the fluid in the stomach, it is probable that the modifying influence of habit is inconsiderable. Habit certainly does not familiarize the system to strychnia used medicinally. The same dose, which has once excited its peculiar physiological action, will for the most part suffice to excite it again, however frequently the dose may be repeated.—The facts mentioned by Mr. Baker show that nux vomica is not a cumulative poison; and European experience, in the instance of strychnia, is to the same effect. _Morbid Appearances._—The morbid appearances differ according to the period at which death occurs. In Mr. Ollier’s case, where death took place in an hour, the appearances were insignificant. The stomach was almost natural, the vessels of the brain somewhat congested, the heart flaccid, empty, and pale. In the case in Hufeland’s Journal there was general inflammation of the stomach, duodenum and part of the jejunum. In Cloquet’s case, a slower one, there was very little appearance of inflammation. In that from the Parisian bulletins, on the contrary, the stomach was highly inflamed, the intestines violet-coloured, in many places easily lacerated and apparently gangrenous. In an interesting dissection of a case, which was quickly fatal,—that related by Orfila and Ollivier, there was found much serous effusion on the surface of the cerebellum, and softening of the whole cortical substance of the brain, but especially of the cerebellum. Blumhardt too, found softening of the cerebellum and congestion of the cerebral vessels, together with softening of the spinal cord and general gorging of the spinal veins. This is some confirmation of an opinion advanced not long ago in France by Flourence and others, that nux vomica acts particularly on the cerebellum.[2353] In Dr. R. D. Thomson’s case, which was examined by Mr. Taylor, there was found much congestion of the whole membranes and substance of the brain and cerebellum, and even some extravasation of blood within the cavity of the arachnoid over the upper surface of the former. Mr. Watt remarked in his case (sixty hours, however, after death in summer) softening of the substance of the brain and the lumbar part of the spinal cord.—In Orfila and Ollivier’s case the lungs were found much gorged with black fluid blood.—In Blumhardt’s case the heart and great vessels were entirely destitute of blood.—There is sometimes seen, as in Dr. R. D. Thomson’s case, a brown powder lining the stomach, even although vomiting may have occurred. The body appears sometimes to retain for a certain period after death the attitude and expression impressed on it by the convulsions during life. In the instance mentioned by Orfila and Ollivier the muscles immediately after death remained contracted, the head bent back, the arms bent, and the jaws locked. This state may even continue for some hours, so that the body appears to pass into the state of rigidity which precedes decay, without also passing through the preliminary stage of flaccidity immediately after death. In the case related by Mr. Ollier, the body five hours after death “was still as stiff and straight as a statue, so that if one of the hands was moved the whole body moved along with it;” and in Blumhardt’s case the rigidity twenty hours after death was unusually great. This state of rigidity, however, does not invariably occur. On the contrary, in animals the limbs become very flaccid immediately after death; but the usual rigidity supervenes at an early period.[2354] In Dr. R. D. Thomson’s case flaccidity immediately followed death. _Treatment._—Little is known of the treatment in this kind of poisoning. But it is of the greatest moment to evacuate the stomach thoroughly, and without loss of time. Hence emetics are useful; but if the stomach-pump is at hand it ought to be resorted to without waiting for the operation of emetics. Torosiewicz describes the case of a young woman who, after the usual symptoms had begun to appear in consequence of the administration of a tea-spoonful of powder, recovered under the action of an emetic followed by rhatany-root.[2355] When nux vomica is taken in powder,—the most frequent form in which it has been used,—it adheres with great obstinacy to the inside of the stomach. Consequently whatever means are employed for evacuating the stomach, they must be continued assiduously for a considerable time. If the patient is not attacked with spasms in two hours, he will generally be safe. M. Donné of Paris has stated that he has found iodine, bromine, and chlorine to be antidotes for poisoning with the alkaloid of nux vomica, as well as for the other vegetable alkaloids. Iodine, chlorine, and bromine, he says, form with the alkaloid compounds which are not deleterious,—two grains and a half of the iodide, bromide, and chloride of strychnia, having produced no effect on a dog. Animals which had taken one grain of strychnia or two grains of veratria, did not sustain any harm, when tincture of iodine was administered immediately afterwards. But the delay of ten minutes in the administration of the antidote rendered it useless. In the compounds formed by these antidotes with the alkaloids, the latter are in a state of chemical union, and not decomposed. Sulphuric acid separates strychnia, for example, from its state of combination with chlorine, iodine, or bromine, and forms sulphate of strychnia, with its usual poisonous qualities.[2356] It remains to be proved that the same advantages will be derived from the administration of these antidotes in the instance of poisoning with the crude drug, nux vomica, as in poisoning with its alkaloid. In general little difficulty will be encountered in recognizing a case of poisoning with nux vomica. _Tetanus_ or locked-jaw is the only disease which produces similar effects. But that disease never proves so quickly fatal as the rapid cases of poisoning with nux vomica; and it never produces the symptoms of irritation observed in the slower cases. Besides, the fits of natural tetanus are almost always slow in being formed; while nux vomica brings on perfect fits in an hour or less. It is right to remember, however, that nux vomica may be given in small doses, frequently repeated, and gradually increased, so as to imitate exactly the phenomena of tetanus from natural causes. Medical men will be at no loss to discover, on reflection, how the preparations of this drug may be rendered formidable secret poisons. _Of Poisoning with the St. Ignatius Bean and Upas Tieuté._ The _Strychnos Sancti Ignatii_, or St. Ignatius bean, contains about three times as much strychnia as nux vomica, namely, from twelve to eighteen parts in the 1000. It is very energetic. Dr. Hopf has mentioned an instance of a man, who was attacked with tetanus of several hours’ duration after taking the powder of half a bean in brandy, and who seems to have made a narrow escape.[2357] The _Strychnos tieuté_ is the plant which yields the Upas tieuté, one of the Javanese poisons. This substance has been analyzed by Pelletier and Caventou, and found to contain strychnia.[2358] From the experiments of Magendie and Delille, the Upas tieuté appears to be almost as energetic as strychnia itself.[2359] Mayer found that the bark of the plant which yields it, when applied in the dose of fifty grains to a wound, killed a rabbit in two hours and a half.[2360] Dr. Darwin has given an account of its effects on the Javanese criminals, who used formerly to be executed by darts poisoned with the tieuté. The account quoted by him is not very authentic; yet it accords precisely with what would be expected from the known properties of the poison. He says, that a few minutes after the criminals are wounded with the instrument of the executioner, they tremble violently, utter piercing cries, and perish amidst frightful convulsions in ten or fifteen minutes.[2361] _Of Poisoning with False Angustura Bark._ Besides these poisons of the genus Strychnos, the present group comprehends another, of the same properties, which was once supposed to be derived from a plant of a different family, the _Brucea antidysenterica_. A species of bark, commonly called the false angustura bark, was introduced by mistake into Europe instead of the true angustura, cusparia, or bark of the _Galipea officinalis_. It was long supposed to be the bark of the _Brucea antidysenterica_; but it is now known to be the bark of _S. nux vomica_.[2362] It is a poison of great energy. It gave rise to so many fatal accidents soon after its introduction, that in some countries on the continent all the stores of angustura were ordered to be burnt. It contains a less proportion of strychnia, but more of the alkaloid brucia than nux vomica, the seed of the plant. According to Andral, brucia is twenty-four times less powerful than strychnia;[2363] but the bark itself is as strong nearly as nux-vomica, for Orfila found that eight grains killed a dog in less than two hours.[2364] The symptoms it induces are the same as those caused by nux vomica. They are minutely detailed in a paper by Professor Emmert of Bern.[2365] It appears that during the intervals of the fits the sensibility is remarkably acute: a boy who fell a victim to it implored his physician not to touch him, as he was immediately thrown into a fit. Professor Marc of Paris was once violently affected by this poison, which he took by mistake for the true angustura to cure ague. He took it in the form of infusion, and the dose was only three-quarters of a liqueur-glassful; yet he was seized with nausea, pain in the stomach, a sense of fulness in the head, giddiness, ringing in the ears, and obscurity of vision, followed by stiffness of the limbs, great pain on every attempt at motion, locked-jaw, and impossibility of articulating. These symptoms continued two hours; and abated under the use of ether and laudanum.[2366] Some interesting experiments were made by Emmert with this poison to show that it acts on the spine directly, and not on that organ through the medium of the brain. If an animal be poisoned by inserting the extract of false angustura bark into its hind-legs after the spinal cord has been severed at the loins, the hind-legs as well as the fore-legs are thrown into a state of spasm; or if the medulla oblongata be cut across and respiration maintained artificially, the usual symptoms are produced over the whole body by the administration of it internally or externally,—the only material difference being that they commence more slowly, and that a larger dose is required to produce them, than when the medulla is not injured. On the other hand, when the spinal cord is suddenly destroyed after the symptoms have begun, they cease instantaneously, although the circulation goes on for some minutes.[2367] The true angustura bark has a finer texture than the other, and is darker coloured, aromatic, pungent, and less bitter. The ferro-cyanate of potass causes in a muriatic infusion of the false bark a precipitate, which is first green and then becomes blue; and the same reagent converts into blue the reddish powder which lines the bark. No such effects are produced on the true angustura bark. Nitric acid renders the rusty efflorescence of the spurious bark deep dirty blue, but has no such effect on the true bark; which, besides, never exhibits a yellow efflorescence. With the preceding poisons Orfila has arranged also some poisons used by the American Indians; but, as in Europe they are mere objects of curiosity, it is scarcely necessary to treat of them particularly here. The most interesting and best known of them is the _wourali poison_ of Guiana, variously called woorara, urari, or curare, by different authors. It is believed to have been traced by Martius to a new species of strychnos, the _S. guianensis_, and more recently by Dr. Schomburg to a different species, the _S. toxicaria_ of that traveller. But the action it exerts does not correspond exactly with what would be expected of a plant belonging to that genus. The effects of wourali have been investigated by Sir B. Brodie in the Philosophical Transactions for 1811–12, in Orfila’s Toxicology, in Magendie’s Memoir on Absorption, and in Fontana’s Traité des Poisons. But the most detailed inquiry is that by Emmert, published in 1818. It produces, not convulsions or spasm of the muscles, but on the contrary paralysis, and probably occasions death in this way by suspending the respiration, in the same way as hemlock and conia. According to Emmert’s experiments the spine only is acted on, and not the brain also.[2368] Some remarkable experiments were made in 1839 by Mr. Waterton, to show the power of artificial respiration in accomplishing recovery from its effects. After the animals had fallen down motionless from the action of the poison introduced through a wound, and when the action of the heart had become so feeble as not to affect the pulse, artificial respiration, continued in one instance for seven hours and a half, and in another for two hours, had the effect of restoring the animals to health.[2369]