the heart and lungs were unimpaired: but that those of the brain had ceased, is proved by the animal having continued in a state of complete insensibility; and by this circumstance, that animal heat, to the generation of which I have formerly shewn the influence of the brain to be necessary, was not generated.

Having learned that the circulation might be kept up by artificial respiration for a considerable time after the woorara had produced its full effects, it occurred to me that in an animal under the influ ence of this or of any other poison that acts in a similar manner, by continuing the artificial respiration for a sufficient length of time after natural respiration had ceased, the brain might recover from the impression which the poison had produced, and the animal might be restored to life. In the last experiment, the animal gave no sign of returning sensibility; but it is to be observed, 1. That the quantity of the poison employed was very large. 2. That there was a great loss of animal heat, in consequence of the temperature of the room being much below the natural temperature of the ani. mal, which could not therefore be considered under such favourable circumstances as to recovery, as if it had been kept in a higher temperature. 3. That the circulation was still vigorous when I left off inflating the lungs, and therefore it cannot be known what would have been the result, if the artificial respiration had been longer continued.

Exp. 31.-A wound was made in the side of a rabbit, and one drop of the essential oil of almonds was inserted into it, and imme. diately the animal was placed in a temperature of ninety degrees. In two minutes he was under the influence of the poison. The usual symptoms took place, and in three minutes more respiration had ceased, and he lay apparently dead, but the heart was still felt beating through the ribs. A tube was then introduced into one of the nostrils, and the lungs were inflated about thirty-five times in a minute. Six minutes after the commencement of artificial re spiration, he moved his head and legs, and amade an effort to breathe. He then was seized with convulsions, and agin lay motionless, but continued to make occasional efforts to breathe. Sixteen minutes after its commencement, the artificial respiration was disconti ed. He now breathed spontaneously seventy times in a minus and moved his head and extremities. After this, he occasionally rose, and attempted to walk. In the intervals he continued in a dozing

state; but from this he gradually recovered. In less than two hours he appeared perfectly well, and he continued well on the following day.

The inflating the lungs has been frequently recommended in cases of suffocation, where the cause of death is the cessation of the func tions of the lungs: as far as I know, it has not been before proposed in those cases, in which the cause of death is the cesssation of the functions of the brain. It is probable, that this method of treatment might be employed with advantage for the recovery of persons labouring under the effects of opium, and many other poisons.

III. GENERAL CONCLUSIONS.

The experiments which have been detailed lead to the following

conclusions.

1. Alcohol, the essential oil of almonds, the juice of aconite, the empyreumatic oil of tobacco, and the woorara, act as poisons by simply destroying the functions of the brain; universal death taking place, because respiration is under the influence of the brain, and ceases when its functions are destroyed.

the

2. The infusion of tobacco when injected into the intestine, and upas antiar when applied to a wound, have the power of render. ing the heart insensible to the stimulus of the blood, thus stopping the circulation; in other words, they occasion syncope.

3. There is reason to believe that the poisons, which in these experiments were applied internally, produce their effects through the medium of the nerves without being absorbed into the circulation.

4. When the woorara is applied to a wound, it produces its effects on the brain, by entering the circulation through the divided blood. vesscis; and, from analogy, we may conclude that other poisons, when applied to wounds, operate in a similar manner.

5. When an animal is apparently dead from the influence of a poison, which acts by simply destroying the functions of the brain, it may, in some instances at least, be made to recover, if respiration is "tificially produced, and continued for a certain length of time."

shall now proceed, from the long and formidable catalogue we collected above, to give some description of the growth and natural properties of the more curious poisonous plants.

[Pantologia. Phil. Trans, 1811.

SECTION II.

Cherry Laurel.

Prunus Lauro-cerasus.-LINN.

THE prunus genus embraces a very extensive family, amounting to not less than thirty one species, natives of Europe, Asia, and America, six of which are indigenous to our own country. To this genus belong the common plum tree, bullace, black-thorn, apricot with all its varieties, common cherry, common laurel, Portuguese laurel. To this also belongs the species before us, which is a shrub or small tree, sending off long spreading branches, and covered with smooth brown bark. Leaves evergreen, elliptical, or obovate, blunt, rather serrated, furnished with yellowish glands at the base, of a shining deep green, placed alternately upon strong short footstalks. Flowers on short peduncles, in spikes, which arise at the ala of the leaves. Calyx tubular, ovate, divided at the brim into five pointed reflexed segments. Corolla composed of five petals, which are small, white, roundish. Filaments about eighteen, tapering, inserted in the calyx, furnished with simple antheræ. Germen ob long, supporting a columnar style, terminated by a blunt stigma. Flowers drupous, resembling a small cherry both in its external and internal structure.

It is a native of the Levant, and appears to have been long culti vated in Britain, and by its polished evergreen leaves adds much to the beauty of our shrubberies.

The leaves of the lauro-cerasus have a bitter styptic taste, accompanied with a flavour resembling that of bitter almonds, or other kernels of the drupaceous fruits. The flowers of this plant also manifest a similar flavour. The powdered leaves, applied to the nostrils, excite sneezing, though not so strongly as tobacco.

The kernel-like flavour which these leaves impart being generally esteemed grateful, has sometimes caused them to be employed for culinary purposes, and especially in custards, puddings, blanc. mange, &c. and as the proportion of this sapid matter of the leaf to the quantity of the milk is commonly inconsiderable, bad effects have seldom ensued. But as the poisonous quality of this laurel is

How indisputably proved, the public ought to be cautioned against its internal use.

The following communication to the Royal Society, by Dr. Madden of Dublin, contains the first and principal proofs of the deleterious effects of this vegetable upon mankind. "A very extraordinary accident that fell out here some months ago, has discovered to us a most dangerous poison, which was never before known to be so, though it has been in frequent use among us. The thing I mean is a simple water, distilled from the leaves of the lauro-cerasus.— The water is at first of a milky colour, but the oil which comes over the helm with it, being in a good measure separated from the phlegm, by passing it through a flannel-bag, it becomes as clear as common water. It has the smell of bitter almond, or peach kernel, and has been for many years in frequent use among our housewives and cooks, to give that agreeable flavour to their creams and puddings. It has also been much in use among our drinkers of drams; and the proportion they generally use it in, has been one part of laurel water to four of brandy. Nor has this practice, (however frequent) ever been attended with any apparent ill consequences, till some time in the month of September, 1728, when it happened that one Martha Boyse, a servant, who lived with a person that sold great quantities of this water, got a bottle of it from her mistress, and gave it to her mother, Ann Boyse, as a very rich cordial. Ann Boyse made a present of it to Frances Eaton, her sister, who was a shopkeeper in town, and who she thought might oblige her customers with it. Accordingly, in a few days, she gave about two ounces of the water to a woman called Mary Whaley, who drank about two-thirds of what was filled out, and went away. Frances Eaton drank the rest. In a quarter of an hour after Mary Whaley had drank the water, (as I am informed) she complained of a violent disorder in her stomach, soon after lost her speech, and died in about an hour, without vomiting or purging,

or any convulsion.

The shopkeeper, F. Eaton, sent word to her sister, Ann Boyse, of what had happened; who came to her upon the message, and affirmed that it was not possible the cordial (as she called it) could have occasioned the death of the woman; and to convince her of it, she filled out about three spoonfuls, and drank it. She continued talking with F. Eaton about two minutes longer, and was so earnest

to persuade her of the liquor's being inoffensive, that she drank two spoonfuls more, but was hardly well seated in her chair when she died without the least groan or convulsion. Frances Eaton, who, as before observed, had drank somewhat above a spoonful, found no disorder in her stomach or elsewhere; but to prevent any ill consequence she took a vomit immediately, and has been well ever since."

Dr. Madden mentions another case of a gentleman at Kilkenny, who "mistook a bottle of this laurel water for a bottle of ptisan; what quantity he drank is uncertain, but he died in a few minutes, complaining of a violent disorder in his stomach."

In addition to this, we may refer to the unfortunate case of Sir Theodosius Boughton, whose death, in 1780, an English jury de. clared to be occasioned by this poison. In this case the active principle of the lauro cerasus was concentrated by repeated distil. lations, and given to the quantity of an ounce; the suddenly fatal effects of which must be still in the recollection of the public.

To brute animals this poison is almost instantaneously mortal, as amply appears by the experiments of Madden, Mortimer, Nicholls, Langrish, Vater, Fontana, and others.

The experiments, conducted by these gentlemen, shew, that the laurel-water is destructive to animal life, not only when taken into the stomach, but also on being injected into the intestines, or applied externally to different organs of the body. It is remarked by Abbé Fontana, that this poison, even "when applied in a very small quantity to the eyes, or to the inner part of the mouth, without touching the œsophagus, or being carried into the stomach, is capable of killing an animal in a few instants; whilst applied in a much greater quantity to wounds, it has so little activity, that the weakest animals, such as pigeons, resist its action."

The most volatile is the most active part of the lauro-cerasus; and if we judge from its sensible qualities, an analogous principle seems to pervade many other vegetable substances, especially the kernels of drupaceous fruits; and in various species of the amyg. dalus, this sapid principle extends to the flowers and leaves.

It is of importance to notice, that this is much less powerful in its action upon human subjects than upon dogs, rabbits, pigeons, and reptiles. To poison man the essential oil of the lauro-cerasus must be separated by distillation, as in the spirituous or common