| Carbon Disulphide, | 4 |
| Almond Oil, | 100 |
| Concentrated Acetic Acid,[272] | 100 |
| Ether, | 250 |
| Alcohol, specific gravity ·822, | 400 |
| Glycerin, | 588 |
[272] Phosphorus is very little soluble in cold acetic acid, and the solubility given is only correct when the boiling acid acts for some time on the phosphorus.
Phosphorus exists in, or can be converted into, several allotropic modifications, of which the red or amorphous phosphorus is the most important. This is effected by heating it for some time, in the absence of air, from 230° to 235°. It is not poisonous.[273] Commercial red phosphorus does, however, contain very small quantities of unchanged or ordinary phosphorus—according to Fresenius, from ·6 per cent. downwards; it also contains phosphorous acid, and about 4·6 per cent. of other impurities, among which is graphite.[274]
[273] A hound took 200 grms. of red phosphorus in twelve days, and remained healthy.—Sonnenschein.
[274] Schrotter, Chem. News, vol. xxxvi. p. 198.
§ 273. Phosphuretted Hydrogen.—Phosphine (PH3), mol. weight 34, specific gravity 1·178, percentage composition, phosphorus 91·43, hydrogen 8·57 by weight. The absolutely pure gas is not spontaneously inflammable, but that made by the ordinary process is so. It is a colourless, highly poisonous gas, which does not support combustion, but is itself combustible, burning to phosphoric acid (PH3 + 2O2 = PO4H3). Extremely dangerous explosive mixtures may be made by combining phosphine and air or oxygen. Phosphine, when quite dry, burns with a white flame, but if mixed with aqueous vapour, it is green; hence a hydrogen flame containing a mixture of PH3 possesses a green colour.