Phosphorus is usually found in small, waxy-looking cylinders, which are kept in water to prevent oxidation. It may also occur as the amorphous non-poisonous variety, a red opaque infusible substance, insoluble in carbon disulphide. Ordinary phosphorus is soluble in oil, alcohol, ether, chloroform, and carbon disulphide; insoluble in water. It is much used in rat poisons, made into a paste with flour, sugar, fat, and Prussian blue. Yellow phosphorus is not allowed to be used in the manufacture of lucifer matches, and the importation of such is prohibited. In 'safety' matches the amorphous phosphorus is on the box.

Symptoms.—At first those of an irritant poison, but days may elapse before any characteristic symptoms appear, and these may be mistaken for those of acute yellow atrophy of the liver. The earliest signs are a garlicky taste in the mouth and pain in the throat and stomach. Vomited matter luminous in the dark, bile-stained or bloody, with garlic-like odour. Great prostration, diarrhoea, with bloody stools. Harsh, dry, yellow skin, purpuric spots with ecchymoses under the skin and mucous membranes, retention or suppression of urine, delirium, convulsions, coma, and death. Usually there are remissions for two to three days, then jaundice comes on, with enlargement of the liver; hÆmorrhages from the mucous surfaces and under the skin; later, coma and convulsions. In chronic cases there is fatty degeneration of most of the organs and tissues of the body. The inhalation of the fumes of phosphorus, as in making vermin-killers, etc., gives rise to 'phossy-jaw.'

Post-Mortem Appearances.—Softening of the stomach, hÆmorrhagic spots on all organs and under the skin, fatty degeneration of liver, kidneys, and heart, blood-stained urine, phosphorescent contents of alimentary canal.

Treatment.—Early use of stomach-pump and emetics, followed by the administration of permanganate of potassium or peroxide of hydrogen to oxidize the phosphorus. Oil should not be given. Sulphate and carbonate of magnesium, mucilaginous drinks. Sulphate of copper is a valuable antidote, both as an emetic and as forming an insoluble compound with phosphorus.

Fatal Dose.—One grain and a half.

Fatal Period.—Four hours; more commonly two to four days.

Detection of Phosphorus in Organic Mixtures.—Mitscherlich's method is the best. Introduce the suspected material into a retort. Acidulate with sulphuric acid to fix any ammonia present. Distil in the dark, through a glass tube kept cool by a stream of water. As the vapour passes over and condenses, a flash of light is perceived, which is the test.