found that dogs might be made to swallow 7-1/2 drachms without any permanent harm being sustained, provided they were allowed to vomit; for in a few seconds the whole poison was invariably discharged, and the animals, after appearing to suffer for four or five hours, gradually recovered their usual liveliness. But the result is different if the gullet be tied: violent efforts to vomit ensue, and death follows in three days, the intermediate phenomena being those of local irritation chiefly, and the appearances in the dead body those of incipient inflammation of the stomach, without corrosion.—When injected into the veins, the effect of sulphate of zinc is much more violent, in an inferior dose. Forty-eight grains occasioned almost instant death; and half the quantity proved fatal in three minutes. Orfila does not appear to have ascertained the cause of death in the last two experiments. But Mr. Blake found that when this salt is injected into the veins in the dose of three grains, it causes some depression of the heart; that thirty grains arrest the action of the heart in eight seconds, leaving that organ exhausted of irritability and full of florid blood in its left cavities; and that when injected into the arterial system in the dose of sixteen grains, it seemed not to cause any obstruction of the capillaries, but to act on the nervous system, producing extreme prostration, without insensibility or convulsions.[1] These experiments, when taken together, show that sulphate of zinc, though a moderately active irritant, is more indebted for its activity to a remote operation on some vital organ.
Sulphate of zinc is absorbed in the course of its action; for Orfila has lately found it by his process for complex mixtures in the spleen, liver, and urine of animals.[2]
The effects of the preparations of zinc on man in large doses have not been particularly studied. In the dose of a scruple or a drachm, the sulphate is the most immediate emetic known; and it is to be inferred, that if larger doses are rejected, as is the fact, with equal rapidity, they will in general cause no more harm than the medicinal dose.
Nevertheless, some people have suffered severely from over-doses of sulphate of zinc, and a few have even perished. Instead of presenting here a general view of the symptoms, it will be preferable to relate the heads of such cases as have been published.
The first to be mentioned is related by Foderé, who, in consequence of the violent symptoms produced, assigns to the present poison very active properties. "A patient of mine," says he, "a custom-house officer, having got from a druggist six grains of sulphate of zinc to cure a gonorrhœa, was attacked with inflammation in the lower belly, attended by retraction of the navel and severe colic, which yielded only to repeated blood-letting, general as well as local, oleaginous emollients, opiates, and the warm-bath."[3] This case is noticed here chiefly to prevent any one from being misled by it, as it
