PROPERTIES.--A white, hard, solid, generally in the form of pencils or canes of a finely granular fracture; becoming gray or grayish-black on exposure to light in the presence of organic matter; odorless, having a caustic, metallic taste. Soluble in water and alcohol. ARGENTI NITRAS FUSUS--MOULDED SILVER NITRATE--LUNAR CAUSTIC DERIVATION.--Melt silver nitrate, 100 parts, with hydrochloric acid, 4 parts at as low a temperature as possible. Mix and pour into suitable moulds. PROPERTIES.--Practically same as mitigated silver nitrate. Use only externally. ACTIONS.--Silver nitrate combines with the albumen of the tissues, and is a limited caustic; causes superficial inflammation and stains the parts black; small doses increase secretion and stimulate the heart. It promotes nutrition, and is said to be a nerve tonic. Its continued administration causes waste, gastro-intestinal catarrh, fluidity of the blood, slate colored lines about the gums, and similar discoloration of the skin and mucous membrane, followed by nervous disorder, paralysis, convulsions and death. USES.--A solution of forty grains to one ounce of spirit of nitrous ether is said to abort superficial inflammation, if early applied; used for erysipelas, twenty grains to one ounce of distilled water, applied around margin to limit the area; also used in ulceration of the throat; used with a spray or swab, in strength of from ten grains to one-half to drachm to one ounce of distilled water. For dysentery, internally and as an enema it is very good; used in conjunctivitis one to five grains to one to two ounces of distilled water, is the average strength, and should only be applied to the conjunctiva or lids, and should not be on the cornea, as it may form an insoluble chloride of silver and cause permanent opacities. Nitrate of silver is used in the form of lunar caustic to stimulate indolent ulcers, and to burn off warts. To stimulate ulcers, touch in spots around the edge; also used in chorea epilepsy and chronic spinal disease, foot rot in sheep; a piece of the caustic is placed in sinuses of fistulous withers, quittors, etc. It causes a slough, followed by healthy granulation; used for sore teats in cows. ARNICAE--ARNICA ORIGIN.--Arnica is obtained from the flower roots of a plant that grows in mountainous countries of Central Europe, Asia and America. COMPOSITION.--An active principle called arnicin. The root contains an essential oil, on which depends in great part its physiological activity. PREPARATIONS EXTRACTUM ARNICAE RADICIS--EXTRACT OF ARNICA ROOT (NON-OFFICIAL) DOSE.--Horses and cattle, 15 grs. to 1 dr.; sheep and pigs, 5 to 10 grs.; dogs, ¹⁄₂ to 3 grs. FLUIDEXTRACTUM ARNICAE RADICIS--FLUIDEXTRACT ARNICA ROOT (NON-OFFICIAL) DOSE.--Horses and cattle, 1 to 3 drs.; sheep and pigs, ¹⁄₂ to 1 dr.; dogs, 2 to 10 ms. TINCTURA ARNICAE--TINCTURE OF ARNICA This is the best and most used preparation of Arnica.