The well-known explosive composition which, for its regularity of effect and convenience in manufacture and use, is still preferred for general purposes to all the new and more violent but more capricious agents. In England it is composed of 75 parts saltpetre to 10 sulphur and 15 charcoal; these proportions are varied slightly in different countries. The ingredients are mixed together with great mechanical nicety, and the compound is then pressed and granulated. On the application of fire it is converted into gas with vast explosive power, but subject to tolerably well-known laws.