It is an essential component of living systems and is found in nervous tissue, bones and cell protoplasm. White phosphorus has two modifications.
Ordinary phosphorus is a waxy white solid.
When pure, it is colourless and transparent. It is insoluble in water, but soluble in carbon disulphide. This form does not ignite spontaneously and it is a little less dangerous than white phosphorus. Both values are quoted on the Pauling scale. For most elements, the most stable allotrope is illustrated.