Kunckel, a native of Hamburgh, was the first who discovered to the world the process for producing phosphorus; though Brandt and Boyle were likewise said to have previously had the art of making it. It was obtained from sal microcosmicum by evaporation in the form of an acid, but has since been found in other animal substances, as in the ashes of bones, and even in some vegetables, as in wheat flour. Keir's chemical Dict. This phosphoric acid is like all other acids united with vital air, and requires to be treated with charcoal or phlogiston to deprive it of this air, it then becomes a kind of animal sulphur, but of so inflammable a nature, that on the access of air it takes fire spontaneously, and as it burns becomes again united with vital air, and re-assumes its form of phosphoric acid. As animal respiration seems to be a kind of slow combustion, in which it is probable that phosphoric acid is produced by the union of phosphorus with the vital air, so it is also probable that phosphoric acid is produced in the excretory or respiratory vessels of luminous insects, as the glow-worm and fire-fly, and some marine insects. From the same principle I suppose the light from putrid fish, as from the heads of hadocks, and from putrid veal, and from rotten wood in a certain state of their putrefaction, is produced, and phosphorus thus slowly combined with air is changed into phosphoric acid. The light from the Bolognian stone, and from calcined shells, and from white paper, and linen after having been exposed for a time to the sun's light, seem to produce either the phosphoric or some other kind of acid from the sulphurous or phlogistic matter which they contain. See note on Beccari's shells. l. 180. There is another process seems similar to this slow combustion, and that is _bleaching_. By the warmth and light of the sun the water sprinkled upon linen or cotton cloth seems to be decomposed, (if we credit the theory of M. Lavoisier,) and a part of the vital air thus set at liberty and uncombined and not being in its elastic form, more easily dissolves the colouring or phlogistic matter of the cloth, and produces a new acid, which is itself colourless, or is washed out of the cloth by water. The new process of bleaching confirms a part of this theory, for by uniting much vital air to marine acid by distilling it from manganese, on dipping the cloth to be bleached in water repleat with this super-aerated marine acid, the colouring matter disappears immediately, sooner indeed in cotton than in linen. See note XXXIV.