Inflammation

When grains of powder are united to form a charge, and fire is communicated to one of them, the heated and expansive gases evolved insinuate themselves into the interstices of the charge, envelop the grains, and ignite them, one after the other. This propagation of ignition is called inflammation , and its velocity the velocity of inflammation . It is much greater than that of combustion, and it should not be confounded with it. The velocity of inflammation of powder compre ed by pounding is about.64 inch, while that of mealed powder in the same condition is only.45 inch. Inflammation, in the study of gunpowder, is the spread of the flame from one grain to another—as opposed to ignition; the setting on fire of a certain point of the charge.