Argentum,—Silver.

Preparations.

Argenti Oxidum, Silver Oxide,—Dose, gr. ss-ij, in pill. Is nearly insoluble in water, and is not dangerous as an internal remedy.

Argenti Nitras, Silver Nitrate,—Dose, gr. ⅙-½; if watched, up to gr. j may be given best in pill or distilled water and alone never with Tannin or a vegetable extract, lest an explosive compound result.

Argenti Nitras Fusus, Melted Stick, Lunar Caustic,—for local use.

Argenti Nitras Dilutus, Diluted Silver Nitrate, Mitigated Caustic,—has ⅔ Potassium Nitrate, and is used locally by ophthalmologists.

Argenti Iodidum,—Silver Iodide,—Dose, gr. ¼-j, in pill. Is supposed not to discolor the skin, even if taken continuously.

Incompatibles. The Nitrate is exceedingly sensitive to organic matter and light, and decomposes readily. All soluble Chlorides are incompatible with it, precipitating the chloride of silver; hence it should be given in distilled water. Most mineral Acids and their salts, Alkalies and their carbonates, Aqua Calcis, and Astringent Infusions are also incompatible with the silver salts.

Antidote to the Silver Salts. Common Salt freely, it precipitating the insoluble chloride of silver, and also acting as an emetic.

Physiological Action. Silver Nitrate combines with the albumen of the tissues and is a limited escharotic. It excites superficial inflammation, and stains the part black under the influence of light. The stains may be removed by washing with a strong solution of Potassium Cyanide.

In Small Doses it increases secretion, stimulates the heart, promotes nutrition, and acts as a nerve tonic. Its Continued Administration produces gastro-intestinal catarrh, waste of tissue, uraemia, albuminuria, fatty degeneration of the heart, liver and kidneys, hemorrhages, fluidity of the blood, a slate-colored line along the gums, and a similar discoloration of the skin and mucous membranes, with centric impairment of the nervous system, causing paralysis on a large scale, loss of coördination, convulsions, and finally death by paralysis of respiration. These symptoms are collectively termed Argyria.

Large Doses produce violent gastro-enteritis, and ulcer of the stomach, from thrombosis of its veins.

Regulation of a course of Silver Medication. The administration of the remedy should be suspended after five or six weeks, and elimination promoted by purgatives, diuretics and baths. To prevent the general discoloration, Potassium Iodide should be given conjointly with the silver, and baths of Sodium Hyposulphite used.

Therapeutics of the Silver Salts. Locally the Nitrate is much used as a stimulant application, an astringent, a caustic, an alterative, and an antiphlogistic. A solution in Nitrous Ether (gr. xl ad ℥j) will abort—

Superficial Inflammations, if applied early to the neighboring integument.

Erysipelas, by Higginbotham's method, the solution (gr. xx ad ℥j) applied over the inflamed surface and beyond, after careful washing and drying.

Throat Diseases,—the Nitrate is used, but salts of Copper are better.

Ulcers of the tongue and tonsils,—the solid stick may be applied locally.

Dyspepsia, with vomiting of yeasty fluid—the Nitrate internally.

Chronic Gastritis and Gastric Ulcer,—the Oxide in ½- grain doses ter die. The Nitrate may be combined with Belladonna or Hyoscyamus in chronic gastric catarrh, in which it is often very efficient.

Dysentery of chronic type, especially if rectal ulcer,—the Nitrate internally and by enema, is one of the best remedies.

Diarrhoea,, of phthisis and typhoid fever,—the Nitrate with Opium.

Conjunctivitis,—solutions of various strengths (gr. j-x ad ℥j of distilled water); when corneal ulcers exist, it must be cautiously used, or opacities due to deposits of the metal will remain in the cornea.

Chronic Spinal Inflammations, causing locomotor ataxia or paraplegia—the Nitrate has in some few cases effected permanent cures.

Epilepsy, was formerly much treated with the Nitrate, and it occasionally achieved the most brilliant results, but colored the skin blue.

A Compend of Materia Medica, Therapeutics, and Prescription Writing, 1902, by Sam'l O. L. Potter, M.D., M.R.C.P.L.