Inanimate foreign bodies are not unfrequently met with in the organism.

They are introduced accidentally or designedly, either through the natural orifices, as the mouth, the anus, the orifices of the urethra and vagina, the ears, the nostrils; or else by violence, at various parts, as by means of projectiles, of puncture, of a blow, of cautery, etc.

They include things the most dissimilar, as fish- and other bones, fruit stones and seeds, coins, rings, natural and artificial teeth, straw, ears of grain, pencils, needles, tobacco-pipe fragments, dagger and sword points, knives, gunshot materials of all kinds, fragments of dress, of glass, pigments.

These foreign bodies are often got rid of, sooner or later, through the natural channels. Occasionally, however, they abide long - it may be for life - without occasioning serious annoyance, and are afterwards found to have become isolated within a callous exudate-capsule.

In other cases, they give rise to various, more or less perilous symptoms, and not unfrequently prove fatal. Thus, they may act as plugs, or injure in many other ways every variety of organ. Again, they may induce and sustain inflammation and ulceration to the exhausting point.

A certain interest attaches to the migrations of foreign bodies, as now and then witnessed in the case of needles, grain-ears, and bullets; these being, after a longer or shorter interval, discovered or, perhaps, spontaneously ejected through suppuration, at parts of the body remote from the point of their introduction. These migrations are sometimes the result of gravitation, as in the case of bullets. At other times they are obviously quite independent of this motive power.