PHOSPIIORUS. So called from its property of shining in the dark. It was discovered in 1668 by Brandt, an alche mist of Hamburgh, and was originally obtained by distilling urine ; but it is now always extracted from banz earth, by a process contrived by Scheele. The bones are calcined, so as to destroy the animal matter, and, being powdered, are mixed with water, to which half their weight of sulphuric acid is added. The bone earth, consisting chiefly of phosphate of lime, is thus decomposed, sulphate of lime is formed, and phosphoric acid is evolved ; or, rather, superphosphate of lime, which, being much more soluble than the sul phate, remains in the liquid, and may be obtained by its evaporation ; it is mixed with about half its weight of charcoal, and put into a well-luted earthen retort, the beak of which dips into water. At a bright red heat, the phosphorus distils over into the water. It is purified by carefully melting it under water, and straining it through a piece of chamois leather.
Pure phosphorus is almost colorless, and sem- transparent; it may be cut with a knife, and its surface has a waxy lustre. It fuses at 108°, boils at 550°, and is con verted into vapor, having, according to Dumas, a density = 4.35. It is sparingly soluble in fixed and volatile oils, and in ether and alcohol,. but insoluble in water. It shines in the dark, and emits a lumin ous vapor, undergoing a slow combustion, and exhaling a peculiar smell like garlic. When rubbed, or heated to a temperature of about 110°, it takes fire and burns with great rapidity, with a white flame, emit ting abundance of acid fumes ; in oxygen gas its combustion is so intensely brilliant that the eye can scarcely bear the light.
The product of the perfect combustion of phosphorus is phosphoric acid, a fusible substance, very soluble in water, and in tensely sour. It appears to consist of 1 equivalent of phosphorus = 16, and 21 of oxygen = 20 ; its equivalent being 36. There are two other acids of phospho rus: namely, the phosphorous acid, con sisting of 16 phosphorus -I- 12 oxygen ; and the hypophosphorous acid, which ap pears to be a compound of 2 equivalents of phosphorus (16 x 2) = 82, and 1 of oxy gen = 8. When phosphorus is boiled in a solution of caustic potash a gas is evolv ed, which is remarkably distinguished by its spontaneous inflammability ; each bub ble, as it rises through the water, taking fire upon the surface, and producing a beautiful ring of smoke : this gas is com monly called phosphuretted hydrogen. Phosphorus may be made to combine with the greater number of the metals, forming compounds called phosphurets.
Wohlcr recommends as likely to afford phosphorus at a very cheap rate, to distil by a strong heat ivory black, with half its weight of fine sand and charcoal powder.
A silicate of lime is formed, and the car bonic oxide and phosphorus come over.
If phosphorus be put with alcohol into a bottle, and shaken for some time, it may be obtained in powder of the utmost tenuity, which, when diffused through the alcohol, appears as if it consisted of a multitude of minute crystals.
At the temperature of 60° F., or up wards, carbon in the form of animal char coal, or lamp-black, causes the inflamma tion of a stick ofphosphorus powdered with it, and the effect takes place either in the open air, or in a close receiver of a moderate size.
Phosphorus Bottle.—In a phial, mix, by gentle for half an hour, 2 drs. of phosphorus, with 1 dr. of lime. Or, in a phial, with water, melt 1 dr. of phospho rus, and 15 grs. of white wax. On cool ing, as the mass grows solid, turn the phial till the inside is coated, when dis charge the water, and dry cool.
Canton's Phosphorus is formed by mix ing three parts of calcined oyster-shells in powder, with one of flowers of sulphur, and ramming the mixture into a crucible, and igniting it for half an hour. The bright parts will, on exposure to the sun beam, or to the common daylight, or to an electrical explosion, acquire the pro perty of shining in the dark, so as to illu minate the dial of a watch. It will, after a while, cease to shine ; but, if we keep the powder in a well-corked phial, a new exposure to the sun's light will restore the phosphorescent quality.
Temperature has a marked effect on the emission of light by these bodies. When they are shining, the luminous appearance ceases if they are exposed to the cold of a freezing mixture. It becomes more vivid by applying heat ; and if it has ceased, it may be renewed by applying a stronger heat, so that a piece of any solar phospho rus, which has apparently lost its power, may by heat be again made to shine, Some of the phosphorescent bodies just mentioned, after their luminousness is over, upon partially heated iron, yield on fusion a very vivid light. Lime is the substance possessing this property in the most remarkable degree. If a piece of calcareous spar is placed on charcoal be fore the compound blow-pipe, it emits a light so vivid and white that it can scarce ly be looked upon.
Phosphorus Match Light.—Into a large heated in a sand-bath, put eight parts of pure phosphorus, which half melt, without allowing it to oxidize. Add four equal parts of magnesia ; begin to mix the whole at a heat of 234.5°; reduce the heat gradually to 106.25°, and in about an hour you will have a fatty pow der, which is to be put into bottles, and, when cold,_ carefully stopped. This sub stance will instantly inflame a common match.