A wound is a division or rent in the soft parts of the body, the result of violence.

Wounds differ in kind according to the manner of their production, and are classed as follows: -

1. Incised Wounds.

2. Lacerated Wounds.

3. Contused Wounds.

4. Punctured Wounds.

There is also a fifth kind - poisoned wounds - which includes all wounds into which poisonous matter or virus has entered.

Incised wounds are such as are produced by a sharp-cutting instrument, as a razor or knife. Here the divided surfaces are smooth and regular, and lend themselves most readily to readjustment. Moreover, the healing process in this description of wound is greatly favoured by the absence of any bruising or tearing of the flesh. The liability to hsemorrhage is much greater, however, than in the other varieties. This is referable to the fact that the vessels, instead of being torn and frayed out at their broken ends, are cut clean through, so that the blood, besides having a free and open passage, meets with no broken shreds of tissue about which to coagulate.

Lacerated wounds result when hooks or blunt instruments enter the flesh and are forcibly torn out. In this case the broken surface is more or less rough and irregular, and loose shreds of tissue sometimes hang from the divided parts. Bleeding is much less considerable than in incised wounds, as in the breaking of the torn vessels their coats become detached from each other, and the inner ones are retracted within the outer one, and thus help to plug up the orifice. Then again, the torn end of the vessel affords a rough and ragged surface about which the blood more readily coagulates than when the vessel is clean-cut.

Contused wounds are produced when, in addition to a division of the tissues, the surrounding parts are more or less bruised. The contusion or bruising, when considerable, has the effect of rupturing the vessels and causing the injured parts to be infiltrated with blood after the manner of a black eye, or it may so far damage the tissues as to cause them to die and to slough. In any case their vitality is impaired to a greater or less extent, and the power of healing correspondingly diminished. Contused wounds, therefore, as we shall presently see, require special consideration in the matter of treatment, since it is not only necessary to bring the divided surfaces together, but to restore vitality in the injured part.

Punctured Wounds are produced by stakes, and pricks with small, sharp- or blunt-pointed instruments, as when nails enter the feet, and stable-forks the limbs and other parts of the body. Here, as in the case of incised and lacerated wounds, the tissues will be cut by a sharp-pointed instrument, and torn by a blunt one. In the latter case there would be, in addition to the severance of the tissues, more or less bruising of the parts through which it passed, and, as in the case of a contused wound, healing would be rendered more difficult, and the condition of the part more dangerous. It is not, however, to these considerations alone that punctured wounds owe their importance. They are usually deep, and the divided surface of the tissues is out of sight. Deep-seated vessels, nerves, and other structures may be severed, and, what is of the first importance, dirt, decomposing matter, or a part of the instrument itself, may lodge in the wound and complicate the injury.

Poisoned Wounds

These are wounds into which one or another of the many forms of poison or virus has gained admittance, either at the time when it was inflicted, or afterwards by accidental contact with them. Although wounds, and the body generally, may suffer by the entrance of mineral poisons, those derived from the vegetable or animal kingdom are by far the more common and hurtful. Nor does it always require that the animal supplying the poison should itself be the subject of disease, as shown by results which follow the sting or bite of insects and serpents. Most commonly, however, animal poisons are either the products of disease or decay. The former is exemplified in the bite of the rabid dog, and the contamination of a healthy wound with the virus of glanders; while the latter finds expression in the inoculation of wounds by decomposing animal matter.