CIIRONIC POISONING BY SILVER NI TBATE.—The prolonged internal use of any of the soluble salts of silver will give rise to chronic poisoning, or argyria. A local argyria, or argyrosis, may be caused by the frequent topical application of a soluble silver salt for a prolonged period. Discoloration of the conjunctiva and of the cornea has been observed. A few cases have been reported in which gen eral argyria has resulted from the topical use of silver in the mouth and throat (Foster). The first sign of general ar gyria is the appearance of a slate-colored line along the gums, associated with some inflammatory swelling. Later gray ish patches appear on the skin and mu cous membranes, and spread over the whole body until the skin has acquired a peculiar bluish-slate color, which may be come very dark, and in decided cases the conjunctiva! and the mucous membrane of the mouth are involved. The silver is found in all the tissues cf the skin below the rete Malpighii (Frommann, Riemer, Neumann). No organ of the body, ex cept the parenchymatous cells and the epithelium, escapes this pigmentation, which is due to the deposit of silver, in the metallic state, as an oxide or as some organic compound. Although the discol oration is long in making its appearance, the deposition in the tissues probably be gins at once and gradually accumulates._ This condition of argyria does not seem, to affect the general health. Foster be lieves that it is not improbable that in all cases a certain, though not serious,, degree of derangement of nutrition is present in these cases.
Treatment of Chronic Poisoning. Prophylaxis is most important. When
the salts of silver are indicated as a treatment to be much prolonged, occa sional discontinuance of the remedy is imperative. At the end of the third week of treatment, the remedy should be stopped for one week; after three months a long intermission should follow. E. Harnack (Arzneimittellehre, 410, '83) asserts that in every recorded case of argyria at least one ounce of the salt had been taken. In the intermissions of treatment by silver salts, the patient should receive a thorough course of purgatives, diuretics, and baths. Iodide of potassium may be given with the silver salts to expedite its elimination (Foster).
Greater or less success has been claimed for various treatments in argyria, but in general they are futile (H. C. Wood). Rogers claims that blistering will lighten the color. Eichmann recommends the use of potash baths and of soap baths, each four times a week. The internal use of potassium iodide may produce some change in the color of the skin, but perfect restoration to the normal is gen erally beyond a reasonable probability_ Therapeutics. — The silver salts are given internally for the relief of gastro intestinal and nervous disorders. The nitrate is most generally employed. It should be given in gastric disorders, in pill form, one-half to an hour before eating, that the stomach may be properly exposed to the medicament. In intes tinal disorders the pills should be coated with keratin, salol, or other substance not acted upon in the stomach.