Retained bullets themselves remained as foreign bodies in a certain number of cases. I cannot say that suppuration never followed the retention of a bullet, since in two of the instances where I saw such removed they lay in a small cavity containing at any rate a 'purulent fluid.' In one of these the bullet was a Martini-Henry, and in both the bullet had been imbedded for some weeks, and had certainly not occasioned a primary suppuration of the wound.
The favourable influence of the pure and dry nature of the atmosphere in this campaign must certainly not be underrated, and in support of this influence I think I may say, from the experience of cases that I saw coming from Natal where the climate and surroundings were not so favourable as on the western side, that suppuration was more common and more severe in the moister atmosphere.
Putting aside all the above remarks, however, I am inclined to think that a general tendency to primary union and the absence of suppuration will always be a feature of wounds from bullets of small calibre, and that this favourable tendency is attributable to certain inherent characters of the injuries. Of these the nature and small size of the openings, the dry character of the lining of the track due to superficial destruction and condensation of the tissue forming its wall, the small disposition to prolonged primary hæmorrhage, and the absence of any great amount of serous exudation during the early stages of healing are the most important.
A mechanical factor of great importance also exists in the spontaneous collapse and automatic apposition of the walls of the track. This closure is rendered additionally effective in many cases by the interruption of the continuous line in the wounded tissues consequent on alteration in the position of the parts traversed when an attitude of rest is assumed by the injured part. The indisposition to suppuration and the apparent unsuitability of the tissue lining the track for the development and spread of infecting organisms are well illustrated by several observations. Thus, even if the bullet be thoroughly aseptic, the fragments of destroyed skin driven into the track by the bullet can scarcely be free from organisms; yet these seldom give rise to trouble. Again, if for any reason a deep portion of a track becomes infected and suppurates, there is no tendency for the spread of infection along the line of wounded tissue, but rather for the development of a local abscess, pointing in the ordinary direction of least resistance, irrespective of the course originally taken by the bullet.
Mauser Wound of Entrance, a little more than 48 hours after infliction. About 12/1.
G. L. Cheatle.
Section of the entry segment of an aseptic Mauser wound removed a little over forty-eight hours after its infliction. Magnified twelve diameters.
The margins of the opening are still sloping and depressed, indicating the originally 'punched-in' nature of the aperture. A thin stratified layer of epidermis completely closes it. No scab remains.