SYSTEMIC POISONS The systemic poisons include the following:— Prussic 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 corn merce 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 dif fused 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 symp toms 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 move ments 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 asphyxial stage is reached, in which there are slow gasping respirations, loss of pulse, and paralysis of motion. Death is frequently preceded by spasms.
The lightning-like 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 am monia, 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.
Strychnine and Strychnine-yielding Plants.—The alkaloids strychnine and brucine, as well as 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. Ac cessions and remissions of the tetanic state ensue rapidly till the patient succumbs, usually within half an hour of the adminis tration of the poison.
The best treatment is to put the patient under the influence of chloroform and wash out the stomach, a full dose of chloral and bromide being afterwards introduced into the stomach.
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 adminis tration 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 io% in combination with meconic acid, which is physiologically inactive.