The deaths of children from lockjaw following a Fourth of July celebration have often exceeded the total deaths in a Central American revolution.
The tetanus bacillus is a widely distributed organism, whose normal habitat is in the soil and which is usually present on the dirty hands of little boys.

The toy-pistol wounds are made by small bits of paper or metal being driven into the skin by the explosion of the cap.

The wound is of little moment, the surface becomes closed, and a bit of foreign substance, a few dead cells and the tetanus bacilli from the surface remain enclosed and in a few days the fatal disease develops.
Infection of the surfaces of old wounds such as the surface of an ulcer takes place with difficulty.

Large numbers of leucocytes which give protection by phagocytosis are constantly passing to the surface, and there is also a constant stream of fluid towards the surface.

On such a surface there may be an abundant growth of pathogenic organisms, but no infection results.
In most infections there is a focus where the infectious organisms are localized; this may correspond to the point of entrance on a surface or it may be in the interior of the body, the organisms being deposited there after entrance.