#Contused and Lacerated Wounds.#--These may be considered together, as they so occur in practice. They are produced by crushing, biting, or tearing forms of violence--such as result from machinery accidents, firearms, or the bites of animals. In addition to the irregular wound of the integument, there is always more or less bruising of the parts beneath and around, and the subcutaneous lesions are much wider than appears on the surface. Wounds of this variety usually gape considerably, especially when there is much laceration of the skin. It is not uncommon to have considerable portions of skin, muscle, or tendon completely torn away. Hæmorrhage is seldom a prominent feature, as the crushing or tearing of the vessel wall leads to the obliteration of the lumen. The _special risks_ of these wounds are: (1) Sloughing of the bruised tissues, especially when attempts to sterilise the wound have not been successful. (2) Reactionary hæmorrhage after the initial shock has passed off. (3) Secondary hæmorrhage as a result of infective processes ensuing in the wound. (4) Loss of muscle or tendon, interfering with motion. (5) Cicatricial contraction. (6) Gangrene, which may follow occlusion of main vessels, or virulent infective processes. (7) It is not uncommon to have particles of carbon embedded in the tissues after lacerated wounds, leaving unsightly, pigmented scars. This is often seen in coal-miners, and in those injured by firearms, and is to be prevented by removing all gross dirt from the edges of the wound.