8. Cantharides.—The administration of cantharides (q.v.) is followed by vomiting, purging, strangury, or even entire inability to pass the urine. In the ejecta portions of the shining elytra or wing-cases of the fly may often be recognized. There is often great excitement of the sexual proclivities. The active principle of the fly, cantharidin, may be extracted from suspected matters by means of chloroform, and the residue left after the evaporation of this blisters the lip or any tender mucous surface to which it is applied. Demulcent remedies, with opiate enemata and injections, afford the best relief by way of treatment.
3. Neurotics.
1. Prussia or Hydrocyanic Acid.—Hydrocyanic acid is one of the best known poisons, and a very deadly one. In the pure state it is said to kill with lightning-like rapidity. It is met with in commerce only in a dilute state. In Great Britain two kinds of acid are commonly sold—the pharmacopoeial acid, containing 2% of anhydrous prussic acid, and Scheele's acid, containing 4 to 5%. Less than a teaspoonful of the 2% acid has caused death. Given in fatal doses, the symptoms of prussic-acid poisoning set in with great rapidity; and, in consequence of the readiness with which the poison is absorbed from the stomach and diffused through the circulation, the onset of symptoms is reckoned by seconds rather than by minutes. Occasionally the victim may be able to perform a few voluntary actions before alarming symptoms are developed. There is first a very brief stage of difficult breathing, and slow action of the heart, with a tendency for the organ to stop in the state of dilatation. With widely dilated pupils of the eye, the patient is then seized with violent irregular convulsive movements. The rhythm of the respiratory movements is disturbed, and the countenance becomes of a bluish cast. The patient now sinks to the ground with complete loss of muscular power; and the third or asphyxia stage is reached, in which there are slow gasping respirations, loss of pulse, and paralysis of motion. Death is frequently preceded by muscular spasms. The foudroyant character of the illness, and the speedy death of the patient, coupled with the peculiar odour of the acid in the breath and atmosphere around the body, seldom leave any doubt as to the nature of the case. The treatment consists in inhalation of fumes of strong ammonia, drinks of warm and cold water alternately, friction of the limbs, and artificial respiration. The subcutaneous injection of atropine, which acts as a cardiac stimulant, may prove serviceable. Other soluble cyanides, more especially cyanide of potassium, a salt largely used in photography and in the arts, are equally poisonous with hydrocyanic acid. (See Prussic Acid.)
2. Opium.—In consequence of the extent to which opium, its preparations, and its active alkaloid morphia are used for the relief of pain, poisoning by opium is of frequent occurrence. It is largely used by suicides; and children, being very susceptible to its influence, frequently die from misadventure after administration of an overdose of the drug. The ordinary preparations of opium are the drug itself, which is the inspissated juice of the oriental poppy, and the tincture, commonly known as laudanum. Opium contains a variety of more or less active principles, the chief of which is the alkaloid morphia, which is present in good opium to the extent of about 10% in combination with meconic acid, which is physiologically inactive. Opium is largely used by Eastern nations for smoking, and there is great discrepancy of opinion as to the extent to which opium smoking is deleterious. The preponderance of opinion is in favour of the view that opium smoking is a demoralizing, degrading, and pernicious habit, and that its victims are sufferers both in body and mind from its use. (See Opium and Morphine.)
3. Strychnine and Strychnine-yleldlng Plants.—The alkaloids strychnine and brucine, as well as all the plants in which they are found, all act in the same manner, being highly poisonous, and causing death after spasms of a severe character Many vermin killers contain strychnine as their active ingredient.
Strychnine, and all substances containing that alkaloid, produce their effects within a very few minutes—usually within ten or fifteen minutes. The patient complains of stiffness about the neck, and his aspect exhibits terror. There is an impression of impending calamity or death. Very speedily the head is jerked back, the limbs extended, the back arched (opisthotonos), so that the body may rest on the head and heels only. In a few moments these symptoms pass off, and there is complete relaxation of the spasm. The spasmodic condition speedily returns, and is brought about by the slightest touch or movement of the patient. Accessions and remissions of the tetanic state ensue rapidly till the patient succumbs, usually within half an hour of the administration of the poison. The best treatment is to put, and keep, the patient under the influence of chloroform till time is given for the excretion of the alkaloid, having previously given a full dose of chloral hydrate. (See Strychnine.)
4 Aconite Poisoning.—The ordinary blue rocket, wolfsbane or monkshood, Acontium Napellus, and an alkaloid extracted from it, aconitine, are perhaps the most deadly of known poisons. One-sixteenth of a grain of aconitine has proved fatal to a man. All the preparations of aconite produce a peculiar burning, tingling, and numbness of the parts to which they are applied. When given in large doses they produce violent vomiting, as a rule, more or less paralysis of motion and sensation, and great depression of the heart, usually ending in death from syncope. Intelligence remains unaffected till almost the last. The treatment consists in the hypodermic injection of digitalin, which is a counter-poison in its action upon the heart. The root of aconite has been eaten in mistake for that of horse-radish.
5. Belladonna.—The belladonna or deadly nightshade, Atropa Belladonna, contains an alkaloid, atropine, which is largely used by oculists to procure dilatation of the pupils of the eye. The bright scarlet berries of the plant have been eaten by children, who are attracted by their tempting appearance. Belladonna produces dilatation of the pupils, rapid pulse, hot dry flushed skin, with an eruption not unlike that of scarlatina, soreness of the throat, with difficulty of swallowing, intense thirst, and gay, mirthful delirium. The treatment consists in evacuation of the poison by means of the stomach-pump, and the hypodermic injection of morphia as a counter-poison.
4. Gaseous Poisons.
The effects of these are varied—some of them acting as irritants, while others have a specific effect, apparently in consequence of their forming chemical compounds with the red pigment of the blood, and thus destroying its capability of acting as a carrier of oxygen.
1. Chlorine and bromine act as powerful irritants. They provoke spasm of the glottis when inhaled, and subsequently induce inflammation of the respiratory mucous membrane, which may prove speedily fatal. Inhalation of diluted ammonia vapour is the best remedy.
2. Hydrochloric or muriatic acid gas and hydrofluoric or fluoric acid gas are irritating and destructive to life. The former is more destructive to vegetable life than even chlorine. They are emitted in many processes of manufacture, and especially in the manufacture of carbonate of soda from common salt; by Le Blanc's process, in the salt-glazing of earthenware, and in the manufacture of artificial manures.
3. Sulphurous Acid Gas.—The gas given off by burning sulphur is most suffocating and irritating. Its inhalation, even in a highly diluted state, may cause speedy death from spasmodic closure of the glottis.
4. Nitrous vapors, or gaseous oxides of nitrogen (except nitrous oxide), are given off from galvanic batteries excited by nitric acid; also in the process of etching on copper. They produce, when diluted, little immediate irritation, but are exceedingly dangerous, setting up extensive and fatal inflammation of the lungs.
5. Ammonia gas is highly irritant, but does not often prove fatal.
6. Carbon dioxide gas is heavier than atmospheric air, is totally irrespirable when pure, and is fatal when present in large quantities in respired air. It is given off from burning fuel, accumulates in pits and wells as choke-damp, and constitutes the deadly after-damp of coal-mines. It is also formed during alcoholic fermentation, and hence accumulates in partially filled vats in which fermented liquors are stored. When it is breathed in a concentrated state, death is almost instantaneous. Persons descending into wells foul with this gas sink down powerless, and are usually dead before they can be removed from the vitiated atmosphere. In these cases there is true asphyxia; but carbonic acid is also a narcotic gas. Persons exposed to an atmosphere partially composed of this gas, but not long enough to produce fatal results, are affected with stertorous breathings, oppression, flushed face, prominent eyes, swollen tongue and feeble pulse. The proper treatment is removal from the foul atmosphere, alternate cold and tepid douches to the chest, friction of the limbs and trunk, and artificial respiration. When animation is restored the patient should be put to bed and kept quiet, but should be carefully watched in case of relapse.
7. Carbon monoxide gas is given off by burning charcoal and other forms of fuel, mixed with carbonic acid. The poisonous effects of charcoal fumes are perhaps due rather to the more poisonous carbonic oxide than to the less poisonous carbonic acid. An atmosphere containing less than 1% of carbonic oxide would doubtless be fatal if breathed for many minutes. Carbonic oxide forms with haemoglobin, the red pigment of the blood, a bright scarlet compound. The compound is very stable, and the oxide cannot be displaced by atmospheric oxygen. Hence the blood after death from the inhalation of carbonic oxide is of a bright arterial hue, which it retains on exposure to air.
8. Coal-gas acts as an asphyxiant and narcotic. The appearances met with after death—more especially the fluid state of the blood—are similar to those observed after death from carbonic oxide gas, which is a constituent of coal-gas, and to which the chief effect of coal-gas may be due.
9. Sulphuretted hydrogen gas is highly poisonous by whatever channel it gains access to the body. In a concentrated form it produces almost instant death from asphyxia. Even in a diluted state it produces colic, nausea, vomiting and drowsiness. This may pass into insensibility with lividity and feeble respiration. The skin is cold and clammy, or bathed in perspiration. The red blood corpuscles are disintegrated. The treatment consists in removal from the contaminated atmosphere, friction to the surface
