(P. Eq.=31.) Phosphorus. (Appendix.) Phosphorus.

Prep. From phosphoric acid or superphosphate of lime (made by acting upon bone ashes with oil of vitriol) by distillation with charcoal, when carbonic acid is formed and phosphorus set free, which sublimes.

Prop. & Comp. A waxy-looking substance, usually in the form of pipes, from being cast into moulds, almost colourless and transparent when fresh, luminous in the dark, from oxidating and forming phosphorus acid (Po3), very easily inflamed; sp. gr. 1.77; melts at 108° Fah.; insoluble in water; soluble in ether, oils, and true naphtha; entirely soluble in boiling oil of turpentine and bisulphide of carbon. When burnt, forms phosphoric acid (Po5); becomes opaque and reddish on the surface when old, from the formation of a suboxide, to prevent which it should be kept in water and in the dark. Phosphorus also exists in a peculiar allotropic condition, known as amorphous or red phosphorus, in the form of a red powder, which may be exposed to the air without giving off any fumes, and may be heated in the open air till the temperature reaches 500°, at which point it takes fire, etc. This variety is not soluble in bisulphide of carbon.

Therapeutics. Very seldom given internally; it is said to act as a powerful stimulant and aphrodisiac, producing considerable gastro-intestinal irritation and other dangerous effects in large doses; it has been employed on the Continent in low fevers, cholera, etc., and in this country in the treatment of phthisis. The fumes of phosphorus produce on individuals exposed to them for a lengthened period, a peculiar disease of the jaw-bone, probably from phosphorus acid being present.

Dose. Gr. 1/40 to gr. 1/10 dissolved in ether or olive oil. Phosphorus is introduced for the preparation of phosphoric acid.