WOUNDS 403 



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 l)y 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 wdiich it passed, and, as in the case of a 

 contused wound, healing would be rendered more difficult, and the con- 

 dition of the part more dangerous. It is not, however, to these considera- 

 tions 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 infiicted, 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. 



