PHOSPHORUS. This elementary, solid, non-metallic body was discovered in 1669, by Brandt, an alchemist of Hamburg ; he kept the mode of preparation for a long time secret, but as he could not conceal the fact of its being obtained from urine, Kunkel tried to procure it from the same source, and he succeeded in the attempt.
It will not be requisite to describe the original mode of preparing this very peculiar substance ; therefore we shall only give an outline of the method at present employed. It has been shown that animal bone [Bose, in NAT. HIST. Drv.] contains a large quantity of phos phoric acid combined with 'lime, forming a phosphate of that earth.
It was first proposed by Scheele to obtain phosphorus from bones.
For this purpose tho bones are ignited or calcined in contact with air till they become white ; when this happens it is a proof that the charcoal derived from the decomposition of the animal matter is entirely burnt off. In this state they consist of phosphate of lime mixed with little else than a small portion of carbonate of lime. After being reduced to a fine powder, they are mixed with sufficient water to form a thin paste, and digested for a day or two with two-thirds their weight of sulphuric acid. In this case sulphate of limo is formed, and the greater part of it remains insoluble, and a superphosphate of lime remains in solution ; this is to be evaporated, and the precipitate formed being separated, the clear fluid, which Is chiefly phosphoric acid, is to be evaporated nearly to dryness, and mixed with about a fourth of its weight of powdered charcoal ; this mixture is to be strongly heated in an earthen retort, the beak of which is immersed in water ; by the action of the heat the phosphoric acid yields oxygen to the carbon, and the results are carbonic acid or oxide, which is evolved in the gaseous state, and the vapour of phosphorus, which is condensed by passing into water.
The crude phosphorus thus obtained is mixed with wet sand and purified by redistillation from a largo cast-iron retort, the neck of which just dips below the surface of water contained in a flat earthen ware pan. The phosphorus is from time to time removed by an iron
ladle and cast into sticks by fusing under warm water in a vessel that has a long glass tube attached to its lower part by a stopcock. The tube is surrounded by cold water contained in a tub, and at first its end is closed by a cork. On opening the tap the melted phosphorus flows into the glass tube, and when it has eolidifiod, tho cork is carefully withdrawn, and with it the rod of phosphorus, fresh liquid phosphorus continuing to flow in. By this means the whole of the phosphorus may be drawn out in one continuous stick of any required diameter, and coiled round in the tub or cut into pieces with scissors while still under water.
Phosphorus is solid, translucent, and nearly colourless ; it ie so soft that it may be iudented by the nail, and it is very readily cut. When heated to Fahr. it fuses, and at 550° is converted into vapour ; it has a peculiar smell when exposed to the air, but this is probably derived from the action of the oxygen of the air upon it. Neither water nor alcuhol dissolves phosphorus, but it is slightly dissolved by ether and by oils. It emits light when exposed to the air in the dark, and hence its name (from xir, light, and calpfly, to carry). It is extremely inflammable, and has been known to take fire spontaneously in the atmosphere when the temperature was not above 60° Fahr. Its specific gravity is about Phosphors is also soluble by the aid of heat in naphtha, bisulphido of carbon, and dichloride of sulphur ; on cooling from solution in the last-mentioned it has been obtained in dodecahedral crystals, and by mere fusion and slow cooling of a larger quantity, it has been procured in octohedral crystals.
Phosphorus may be granulated by fusing under alcohol, or in water containing a little urea, and well agitating till cold.