404 HEALTH AND DISEASE 



HEALING OF WOUNDS 



The manner in which the divided surfaces of a wound are united is 

 not always the same. How this will be effected will depend upon a variety 

 of circumstances, notably the time which elapses between the infliction of 

 the wound and the readjustment or apposition of the parts, the manner 

 in which they are brought together, the nature of the cut surfaces, the 

 presence or absence of foreign matter, the extent of injury done to the 

 surrounding tissues, &c. The time occupied in the process of healing, as 

 most people know, may be very short or very long, according to the 

 extent of the wound and the particular method by which healing is 

 effected. 



By careful observation and enquiry, it has been shown that the healing 

 of wounds may take place in five different ways, viz.: — 1. By immediate 

 union. 2. By primary adhesion, or union by the adhesive inflammation. 

 3. By hlood-clot. 4. By granulation, or by the second intention. 5. By 

 scarring under a scab. To the lay mind, these expressions do not convey 

 much meaning, but by a little explanation they may be made just as 

 intelligible as they appear to the professional reader. 



Immediate Union. — In healing by immediate union, the divided 

 parts, on being brought together, are caused to adhere in the first instance 

 by the sticky nature of the matter which then covers their surface, and 

 in a short time — sometimes not more than twenty-four hours — a firm and 

 perfect connection is re-established between the previously divided parts. 

 Examples of this kind of healing are noticed when, on cutting the finger, 

 the parts are brought together and tightly bound up, when, on removing 

 the wrapping, complete repair is found to have been effected without 

 inflammation or discharge, and with little or no pain or swelling. 



In this case no scar remains to mark the seat of the injury, and no 

 new tissue intervenes between the newly -united surfaces; they have 

 simply grown together. 



Primary Adhesion. — Here, instead of the divided parts growing 

 together directly, as in immediate union, without the intervention of new 

 material, the two surfaces of the wound become covered over with a thin 

 layer of cells incorporated with a quantity of adhesive matter which has 

 exuded from the vessels. Some of the former resemble the round, colour- 

 less corpuscles of the blood, but they soon begin to change their form by 

 lengthening out into thread-like bodies, and ultimately to be resolved into 

 a layer of connective tissue by which the divided parts are firmly and 

 permanently reunited. In the course of these changes, new blood-vessels 

 from the old ones in the adjoining tissue slioot out into the uniting sub- 



