The metal silver itself is not used in medicine, and its preparations are not numerous. The properties of silver will be described under its most important salt.

Argenti Nitras. Silver Nitrate

Prepared by dissolving silver in nitric acid.

Physiological Actions

Silver nitrate has locally a caustic, or corrosive action. It combines with the albumin of the tissues, forming a superficial slough. It has a strong metallic and styptic taste, and in the stomach produces a feeling of warmth. It is decomposed by the gastric juice, and, therefore, does not act as an irritant to the stomach, unless taken in poisonous doses. Silver enters the blood as an albuminate, and, if continued for some time, a part of it remains permanently in the connective tissues, staining them a dull slate-gray, which cannot be removed. This tinge first appears as a line along the gums and teeth, and on the mucous membrane inside the lips and cheeks. In small doses silver is astringent and anti-spasmodic, stimulates secretion and nutritive processes, and is a nerve tonic. Long continued it disorders digestion, and produces a general waste of tissue, albuminuria, rapid and irregular heart action, disturbed respiration, and nervous symptoms, viz.: tetanic convulsions, loss of the power of co-ordination, and paralysis.

Symptoms Of Poisoning

In toxic doses silver causes gastro-enteritis, and the antidote is common salt, given very freely in solution. It forms an insoluble chloride, and also acts as an emetic.

Preparations Of Silver

Average dose of the nitrate, gr. 1/6-0.01 Gm., in pill, given after meals, unless otherwise ordered. Silver nitrate is quickly decomposed, if in solution, by organic matter and by the action of light, and is for that reason kept in dark-colored bottles, and should never be left uncorked. With tannin it forms an explosive compound.

Argenti Nitras Fusus. Moulded Silver Nitrate. Lunar Caustic

Made by evaporating silver nitrate and forming it in pencil-shaped moulds. It is used externally as a caustic. It is not deliquescent; its action is superficial and does not extend beyond the point touched; and the slough formed is rapidly healed. In applying silver nitrate the pencil should always be washed in an antiseptic solution before and after using, and, especially before it is put away, carefully dried.

Argenti Nitras Mitigatus. Mitigated Silver Nitrate. (Mitigated Caustic.)

Made with silver nitrate and potassium nitrate. For local use externally, and is used as an application to the eyelids.