The salts of zinc are, in their stronger forms, caustic; in weaker forms, astringent and antiphlogistic. The activity of the different preparations is in proportion to their solubility and diffusibility. Applied to a broken surface or mucous membrane, the salts of zinc harden the albuminous secretions, check the growth of new cells, and contract the vessels, though in a lesser degree than do lead and silver. The salts of zinc, in the blood, take the form of albuminates. They enter the circulation slowly, do not have the tendency to accumulate and remain fixed in the tissues as do lead, mercury, and copper, and are much more rapidly excreted. They are eliminated by the liver, kidneys, intestinal and mammary glands.
If the use of zinc be long continued there may result a series of symptoms similar to those of lead-poisoning, though less severe - viz., wasting of the tissues and loss of strength; pallor; muscular weakness and trem-bling; colic; fetid breath; constipation; feeble mind; and paralysis.
In cases of acute poisoning by zinc salts the antidotes are lime-water, tannin, in the form of strong tea, carbonate of sodium or potassium, soap-suds, and mucilaginous drinks, milk, etc. Vomiting should be encouraged and, if necessary, the stomach washed out.