In the first place, the learned commentator Dr. Gray observes, that the word here used (hebenon) was more probably designated by a metathesis, either of the poet or transcriber, for henebon, i. e. henbane. Now it appears from Gerarde that tabaco was commonly called “henbane of Peru” (Hyoscyamus Peruvianus); and when we consider how high the prejudice of the court ran against this herb, as so strikingly evinced by the ‘Counterblaste’ of King James, it seems very likely that Shakspeare, who was fond of playing the courtier, should have selected it, as an agent of extraordinary malignity, upon such an occasion. No preparation of the hyoscyamus with which we are acquainted, would produce death by an application to the ear; whereas the essential oil of tobacco might, without doubt, occasion a fatal result. The term distilment has also called forth a remark from Steevens, which is calculated to add a little farther weight[[449]] to our conjecture; “surely” says he, “this expression signifies, that the preparation was the result of a distillation.”
Symptoms of poisoning by Tobacco.
The leaves of tobacco, whether whole, or reduced to powder, as they are daily met with in commerce, or in the form of infusion in water or wine, or in the state of smoke, are endued with poisonous properties of extreme energy. Their administration is shortly followed by vertigo; severe nausea; vomiting; a general tremor of the body, which is rarely the result of any other poison; cold sweats; syncope; and death. The author remembers witnessing a lamentable exemplification of the action of tobacco upon a person labouring under a strangulated hernia. The patient had been under the care of a medical practitioner in the vicinity of London, who after repeated and fruitless efforts to return the intestine, injected an infusion of tobacco into the rectum, and sent him in a carriage to the Westminster hospital, for the purpose of undergoing the operation; but the unfortunate man expired very shortly after his arrival, in consequence of the effects of the tobacco clyster. The external application of tobacco, in the form of cataplasm, or infusion, will occasion all the effects above related. A woman applied to the heads of three children afflicted with tinea capitis, a liniment consisting of powdered tobacco and butter, soon after which they experienced vertigo, violent vomiting, and fainting.[[450]]
It was formerly a practice to inject the smoke of tobacco into the anus, by means of a bellows of a peculiar construction, in cases of suspended animation, with a view to stimulate the rectum, and thereby to revive the vital powers; we have already commented upon this most dangerous and mistaken notion, (see page [88].)
In the process of smoking tobacco, the oil is separated, and being rendered empyreumatic by heat, it is thus applied to the fauces in its most active form; whence vertigo, nausea, and all its characteristic symptoms speedily arise upon that occasion; although the system becomes easily habituated to the action of this narcotic, and we continually see a large portion of the community using it daily, in various ways, and in great quantities, as a luxury, without experiencing any other bad effect than that which arises from their inability to relinquish the habit.
The well known errhine, snuff, is prepared from the dried leaves of tobacco, and possesses all the powers of the plant. The celebrated Santeuil experienced vomiting and horrible pains, amidst which he expired, in consequence of having drank a glass of wine, into which some Spanish snuff had been introduced.[[451]]
Physiological action of Tobacco.
The deleterious effects of this plant appear to depend on an especial action upon the nervous system; but farther experiments are required to establish through what medium its powers are conveyed to the sensorium. Orfila concludes that the active part of the plant is absorbed, and carried into the circulation. Mr. Brodie’s experiments, however, would lead to the conclusion that it operates through the medium of the nerves; and, what is extremely singular, they shew that the essential oil operates very differently from the infusion of tobacco; for that while the former appears to act exclusively on the brain, leaving the power of the circulation unimpaired, the latter acts on the heart at once, suspending its action even before the animal ceases to respire, and kills by producing syncope. This apparent anomaly at first led Mr. Brodie, as he has since informed the author, to suspect the accuracy of his experiments; but their careful repetition rendered this impossible. We suggested to him, whether a probable explanation might not be found in the late chemical results respecting the composition of tobacco, which seemed to shew that this plant possesses two active elements.[[452]]
Hemlock. Cicuta.[[453]]
Conium[[454]] Maculatum (Pentandria Digynia. Nat. Ord. Umbellatæ.)
Hemlock is a biennial, umbelliferous, indigenous plant, growing very commonly about the sides of fields, under hedges, and in moist shady places. It is at once distinguished from other umbelliferous plants, with which it may be confounded, by its large and spotted stem, the dark and shining colour of its lower leaves, and their disagreeable smell; which, when fresh and bruised is said to bear a strong resemblance to that of the urine of a cat. Many[[455]] cases of persons who have been poisoned by this plant are to be found in the writings of different toxicologists. The extract, if properly prepared, is a very energetic substance, and gives rise, in large doses, to all the symptoms which we have so often described as the result of narcotic poisons. In those fatal cases, where the bodies have been examined, post mortem, inflammation of the stomach, and sanguineous congestion in the brain, have been the most prominent phenomena. It would appear that the active element of this plant is absorbed and carried into the circulation, through which medium it exerts its action on the nervous system, and more particularly on the brain. At the same time it seems to excite a local irritation, capable of producing an inflammation more or less violent. The best antidote is vinegar, after the stomach has been evacuated, and the cerebral excitement reduced by bleeding and purging.