Ignition

A substance may be set on fire by the direct application of a heated body, by the heat due to sudden shock, friction, or the resisted electric current. Gunpowder under ordinary circumstances requires a temperature of ab. 300° C.; but increased density, moisture, sphericity of grain, and the smoothne arising from glazing, will give a higher temperature for ignition. The presence of gunpowder dust and angular projections will lower the temperature.