a name given to certain substances which shine in the dark without emitting heat. By this circumstance they are distinguished from the pyrophori, which though they take fire on being exposed to the air, are yet entirely destitute of light before this exposure.

Pyrophori are divided into several kinds, known by the names of Bolgianin, phophorus, Mr Canton's phosphorus, Baldwin's phosphorus, phosphorus of urine, &c., of which the last is by far the most remarkable both with respect to the quantity of light which it emits, and its property of taking fire and burning very fiercely upon being slightly heated or rubbed. For the method of preparing these, and for an account of their properties and combinations, see Chemistry Index.