ACONITE
All parts of this plant, the Aconitum Napellus (N.O. Ranunculaceæ), are poisonous. The poisonous properties depend upon the presence of an alkaloid—aconitine—chiefly found in the root.
Poisoning by the alkaloid came before the public mind in the case of Dr. Lamson, executed for the murder of his brother-in-law. The symptoms noticed in that case were very much as detailed below. When any part of the plant is chewed, a sensation of tingling is experienced in the mouth, and burning in the throat. Many of the aconites are, however, inert. The root, having been taken by mistake for horse-radish, has led to several cases of accidental poisoning.
| Aconite | Horse-Radish |
|---|---|
| General Characteristics.— | General Characteristics.— |
| Root conical; dark brown externally, | Root cylindrical, of nearly the same |
| and with numerous twisted rootlets; | thickness down its whole length. |
| internally, the colour is whitish. | Externally, buff-coloured; |
| internally, white. | |
| Taste.—Produces a tingling | Taste.—Sweet and pungent. |
| and numbing sensation in the mouth. |
Symptoms in Man.—The patient complains, within a short time after the poison is taken, of dryness of the throat, accompanied with tingling and numbness of the mouth and tongue. He then complains of nausea, vomiting, pain in the epigastrium, and distressing dyspnœa, of a sensation of formication or tingling, with numbness in his face and limbs, which appear to him heavy and enlarged. In attempting to walk he staggers, his limbs losing their power of supporting his body. He becomes giddy, his pupils dilated, and his sight and hearing imperfect; but he is seldom unconscious till near death. His pulse irregular, gradually becomes weaker, and at last almost imperceptible; his skin cold and clammy; his features pale and bloodless; and his mind clear: then suddenly he dies, in some cases from shock, in others from asphyxia; or he may die from syncope, especially after some exertion.
Symptoms in Animals.—Weakness of the limbs and staggering, the respiration slow and laboured, loss of sensation, paralysis, dimness of vision, increasing difficulty in breathing, convulsions, and death by asphyxia.
Delirium is present in some cases, and dilatation of the pupil has also been noticed. In a case recorded in the British Medical Journal, 1877, vol. i. p. 258, two ounces of the tincture of aconite were drunk in mistake for Succus Limonis; recovery took place, but not before alarming symptoms had taken place, and death at one time appeared imminent.
Post-mortem Appearances.—General venous congestion. The brain and its membranes are, in most cases, found congested and the stomach and intestines inflamed.
Fatal Period.—The symptoms may come on immediately, or may be delayed for an hour or two. In the case mentioned in the British Medical Journal the patient walked about five miles after swallowing two ounces of the tincture, which he drank at 11 o‘clock, returning home at 2.30 P.M. An excise officer, who died in about four hours, was able to walk from the Custom House over London Bridge. Death has taken place in so short a time as one hour and a quarter.
Fatal Dose.—About two grains of the extract, and one drachm of the tincture. Much will depend upon the amount of the alkaloid present. One drachm of the scraped root is said to have proved fatal. One-fifteenth of a grain of aconitine has proved fatal.
Chemical Analysis and Tests.—The alkaloid must be isolated from the contents of the stomach by the process of Stas. The physiological test consists in placing a small portion of the extract, or the alkaloid so obtained, on the tongue or lip, and noting if tingling be produced. To the pure alkaloid, nitric acid added produces no change of colour. Officinal phosphoric acid added, and the mixture carefully evaporated, a violet colour is produced; this reaction is due to impurities in the aconitine.
Kundrat‘s Test.—A solution of ammonium vanadate in strong sulphuric acid produces a coffee colour with aconitine.
Treatment.—Emetics, stomach lavage, castor-oil, and animal charcoal should be given. The administration of digitalis in aconite poisoning has been attended with good results. (See British Medical Journal, 11th December 1872.) The drug may be given hypodermically as an antidote. Stimulants will be required; and friction down the spine, together with galvanism and artificial respiration, may be tried.
Synopsis of the Action of Aconite
1. On Nervous System.—Giddiness, numbness, and tingling in the limbs is a primary effect, followed by gradually increasing paralysis of the muscles, and insensibility of the surface of the body to pinching and pricking. Dr. Fleming asserts that it produces a powerful sedative effect on the nervous system. At any rate, it now seems to be proved that aconite paralyses the sensory nerves, commencing at their peripheral endings.
2. On Vascular System.—Extreme depression of the circulation is produced by doses large enough to cause death. The pulse may become imperceptible at the wrist. In medicinal doses, aconite lowers the heart‘s action; in poisonous doses, it causes fatal syncope.
3. On Digestive System.—Some have denied the irritant action of aconite on the alimentary canal, but Sir R. Christison states that he was deterred from the use of aconite “by two patients being attacked with severe vomiting, griping, and diarrhœa.”
CHAPTER XII
CEREBRAL POISONS
The symptom most characteristic of these poisons is the marked anæsthesia which they produce when their vapours are inhaled. The hydrate of chloral, though placed under the above heading, is more closely allied in its action to opium than to ether or chloroform.