Both by accident and through suicidal or murderous intent, this is one of the most frequently fatal poisons. Symptoms of arsenical poisoning are complex. It is an irritant-neurotic in its action. About an hour after taking it, there are symptoms of faintness, heat of throat, thirst, and burning pain in the stomach. Violent retching and vomiting follow, and the pain extends through the bowels, with straining and severe purging; sometimes with bloody passages. Prostration soon results; with coldness, small, frequent pulse, and great feeling of weakness ; not infrequently delirium, convulsions, or even stupor, will precede death. In slower cases, headache, trembling and other distressing nervous symptoms are common. There is, however, considerable variety in the symptoms of poisoning by arsenic. Death results in most cases within twenty-four hours ; exception-tionally, but rarely, in an hour or less ; occasionally, after weeks, or even months of protracted suffering.
If vomiting has not been already copious, give a teaspoonful of mustard or a tablespoonful of salt in a teacupful of warm water ; and follow this with large draughts of warm water, in which magnesia has been stirred and mixed. Magnssia is at least a partial antidote for preparations of arsenic. The most effectual antidote is hydrated peroxide (sesquioxide) of iron; in large doses, in the moist state, and freshly made. This may be prepared by putting Tincture of chloride of iron in water (quantity not of very great consequence, use plenty of it), and then adding aqua ammonia (solution of ammonia or hartshorn). A thick powder will be thus precipitated ;- which, after washing it with clean water, may be given in tablespoonful doses as an antidote for arsenic.