Page:Treatise on poisons in relation to medical jurisprudence, physiology, and the practice of physic (IA treatiseonpoison00chriuoft).pdf/434

 *phuret had as little effect. The effects, which have been occasionally ascribed to lead-shot, and which will be mentioned by and by [see p. 435], seem at variance with these experiments, but cannot outweigh such precise negative results. It is probable that irritant poisoning can be produced only by those compounds which are soluble, such as the acetate, subacetate, and nitrate. It appears indeed from the experiments of Orfila with the acetate and my own with the nitrate, that these compounds are true corrosives, and of no mean energy when given in large doses moderately diluted.

The insoluble compounds, such as the carbonate, red oxide and protoxide, possess little irritant power. The experimentalists of Lyons found litharge to be irritant in large doses of half an ounce. Orfila gave dogs large doses of the red oxide and carbonate without observing any signs of irritation in the stomach. A case has been published of a young woman who swallowed accidentally an ounce and a half of the carbonate without any bad effect whatever either at the time or afterwards; and Dr. Ogston of Aberdeen has informed me he met with a similar case, that of a girl who took an ounce with the view of destroying herself, but without sustaining any harm whatever. In a remarkable case, published by Mr. Cross of London, in which six drachms were taken accidentally by a pregnant female instead of magnesia, vomiting and violent colic were produced, and afterwards fainting, paralysis of the extensor muscles, and contraction of the flexors; all of which symptoms, however, after enduring without abatement till eight hours after the poison was swallowed, gradually disappeared under antidotes and laxatives. But such a case bears no great resemblance either to the acute or chronic form of poisoning with lead, and was probably hysterical. Orfila has found that an ounce and a quarter of sulphate of lead had no effect whatever on a dog. Mr. Taylor mentions a case where the chloride of lead caused vomiting, but no other ill consequence. Dr. Cogswell found that three drachms of iodide of lead caused in a dog merely depression and weakness for a few days; but forty grains killed a rabbit in twelve days, with symptoms of exhaustion and constipation; and doses frequently repeated, to the amount of eleven drachms in eighteen days, killed a dog under symptoms nearly the same.

It may be presumed that all the compounds of lead which are soluble in water or in the animal fluids may produce in favourable circumstances the lead colic and palsy. Dr. A. T. Thomson, indeed, has endeavoured to show by some experiments, that the carbonate is the only compound of lead which possesses this singular power; and that if the acetate of lead produces similar effects, it is only because that salt usually contains an excess of oxide which becomes