Under the head of irritant poisons may be included, (1) mineral acids, as sulphuric, nitric, and hydrochloric acids; vegetable acids, and other salts, as oxalic acid, bin oxalate of potash, and tartaric acid (in doses of half an ounce or more); the alkalies, as pearl-ash (carbonate of potash), soap lyes (carbonate of soda), ammonia and its sesqui carbonate; and metallic compounds, as white arsenic (arsenious acid); yellow arsenic (orpiment), corrosive sublimate, bicyanide of mercury, pernitrate and other salts of this metal, acetate of lead (sugar of lead) in doses of an ounce and upward, carbonate of lead (white lead), sulphate of copper (blue vitriol) subacetate of copper (verdigris), arsen ite of copper (commonly known as &lee.ele's green or emerald green, and much employed under the name of extract of spinach for coloring confectionary), tartarized antimony, chloride of antimony (butter of antimony), chloride of zinc (sir W. Burnett's fluid), nitrate of silver (lunar caustic), sulphate of iron (copperas rind green vitriol), and bichro mate of potash. (2.) Vegetable substances, viz., colocynth and gamboge in large doses, sayin, croton oil, the leaves and flowers of the common elder (Sainbucus nigra), etc. (a.) Animal substances, such as cantharides, to which must be added the occasional cases in which sausages, and certain fish and mollusks, usually quite innocuous, act as irritant poisons.
The ..careutic poisons include opium, hydrocyanic (or prussic) acid, nil of bitter almonds, cyanide of potassium, henbane, especially the seeds, alcohol, ether, chloral, and chloroform; while nareolico-irritant poisons are nux vomica, meadow saffron (co/deka/7i), white hellebore, foxglove, common hemlock, water hemlock, (cicala .virosa), hemlock water-drcpwort (mangle crocata), fool's parsley, thorn-ripple, monkshood or wolf's bane, deadly Indian tobacco (lobelia inflata), the bark and seeds of the common laburnum, the berries and leaves of the yew-tree, and certain kinds of fungi.
The cases in which there are antidotes qualified to neutralize chemically the action of the puisun are few in number. For the mineral acids we must prescribe chalk cr mag nesia in water, with the view of neutralizing them, after which milk should be given freely. The alkalies and their carbonates must be neutralized by vinegar and water, or lemon-juice mixed with water, after which milk should be given. For oxalic acid the antidote is chalk or magnesia in water, by which an insoluble oxalate of lime or mag nesia is formed. i'or arsenic, the hydrated peroxide of iron has been regarded as art antidote, but its efficacy is doubtful: Vomiting should be excited by the administration of a scruple of sulphate of zinc in warm water, and after the stomach has been well cleared out, demulcent fluids, such as flour and water or milk should be given. Corro sive sublimate combines with albumen (white of egg), and forms an insoluble inert mass; nitrate of silver is neutralized by chloride of sodium (common salt) dissolved in water; factorized antimony is to a great degree rendered inert by the administration of decoction of bark or gall-nuts; and acetate of lead is rendered inert by the administration of sul phate of magnesia, which converts it into an insoluble sulphate of lead. In all cases of suspected poisoning, in which the nature of the poison is not known, the safest course is at once to produce vomiting by sulphate of zinc, or in its abserice by a dessert-spoonful of flour of mustard suspended in tepid water, and to continue the vomiting till all the contents of the stomach are discharged, after which milk should be given freely.
Most of the known gases—except hydrogen, nitrogen, and oxygen—have a poison ous action when inhaled into the brgs; but in these cases death, if it ensues, is popu larly said to ire due to suffocation, although strictly speaking aperson who dies from the effect of carbonic acid, or sulphureted hydrogen, or of any other noxious gas, is in reality just as much poisoned :js if he had taken oxalic acid or arsenic. Carbonic acid
(q.v ), although seldom employed as an instrument of murder, is a frequent cause of accidental death, and in France is a common means of self-destruction. It is established by numerous experiments that air containing more than one-tenth of its volume of car bonic acid, will, if inhaled, destroy life in man and the higher animals. In its prim state it cannot be inhaled, because its contact with the larynx causes spasmodic contrac tion of the glottis; but when diluted with two or more volumes of air, it can be breathed, and produces symptoms of vertigo and somnolency; and so great a loss of muscular power, that the individual, if in an erect or sitting position, falls as if struck to the ground. The respiration, which at first is difficult and stertorous, becomes suspended. The action of the heart is at first violent, but soon ceases, sensibility is lost. and the per son now falls into a comatose or death-like state. Those who have been resuscitated usually feel pain in the head and general soreness of the body for some days and in a few severe eases, paralysis of the muscles of the face has remained. As a winter seldom passes without. several deaths being recorded from coal or charcoal being employed as fuel in ill-ventilated rooms (often without any kind of chimney), it, is expedient that every one should know what's to be done in such an emergency. The patient must, of course, be at once removed from the poisonous atmosphere, after which artificial respiration should he had recourse to. If the skin is warm, cold water may be poured on the head and spine: while if the surface be cold, a warm bath should be employed. When respiration is re-established, venesection will often relieve the congestion of the vessels of the brain. The inhalation of oxygen gas is said to have been of service in these cases. Carbonic oxide, which exists largely in coal gas, is at least as active a poi son as carbonic acid, and is doubtless the principal cause of the effects produced by the inhalation of diluted gal. Both carbonic acid and carbonic oxide act as powerful nar cotic poisons. Sulphareted hydmgen, which occurs abundantly in foul drains, sewers, eess-pools, etc., is a gaseous poison whose effects are often noticed. Nothing certain is known of the smallest proportion of this gas required to destroy human life: but air con taining only one eight-hundredth of its volume of this gas will destroy a (I, g: and when the gas exists in the proportion of one two-hundred-and-fiftieth, it will a horse. Dr. Taylor states that the men who were engaged in the construction of the Thames tunnel suffered severely from the presence of this gas, which was probably cterived from the action of the water on the iron pyrites in clay, and which issued in sudden bursts from the walls. By respiring this atmosphere, the strongest and most robust men were in the course of a few mouths reduced to an extreme state of exhaustion, and several died. The symptoms with which they were first effected were giddiness, sickness, and general debility; they became emaciated, and fell into a state of low fever accompanied by delirium. In this case the dilution was extreme; when the gas is breathed in a more concentrated form, the person speedily falls, apparently lifeless. It appears to act as a narcotic poison when concentrated; but like a narcotico-irrritant when much diluted with air.