Observations during the war in South Africa threw fresh light upon the results of gunshot wounds produced by modern projectiles. Of wounds produced by the Mauser bullet, one correspondent (The Physician and Surgeon, 1900, p. 49) states that “the aperture of entrance seldom shows any bruising of surrounding tissue; frequently it has been difficult to locate it, for where the skin is dense and elastic, there is seldom any bleeding. There is never any inversion of the edges, which are sometimes circular in form, and sometimes triangular like a leech-bite. The aperture of exit, where the bullet has not been distorted, is seldom any larger than that of entrance; there is no bruising of surrounding tissue, and no eversion of the edges; bleeding varies, of course, in accordance with the proximity of large, medium, or small blood-vessels in the track, but in the vast majority of cases it is slight.”
The late Sir William MacCormac, quoted by Sir William Stokes (B. M. J., vol. i., 1900, p. 1453), says: “I saw a large number of injuries inflicted by the Mauser bullet, which is remarkable for the small wound it produces. In three-fourths, if not a larger proportion, it was impossible to tell the exit from the entrance wound, they were so similar in appearance.”
In the examination of gunshot wounds we have to consider—
1. Direction in which the Gun was fired.—The track and position of the ball in the body, coupled with the relative position of the body to a window or door through which the gun may have been discharged, and the place where the ball is found, should it have passed through the body, may assist us in forming an opinion. It is often impossible to trace the course of the ball through the cavities of the body, but through the muscles and denser structures this is more easily accomplished. The effects of the ball on surrounding objects may assist very much in finding the direction of its course. Sir Astley Cooper, by a careful consideration of the above suggestions, once correctly determined that a left-handed man had fired the fatal shot.
2. Distance at which the Charge was fired.—In the case of wounds inflicted by a small shot, the scattering of the shot must be our guide. Dupuytren has related a case in which a fowling-piece charged with powder alone and fired at a distance of two or three feet from the abdomen made a round hole in it and killed the man. If the weapon be fired a short distance, e.g. a few inches from the body, the skin will be scorched, smoke-blackened, and tatooed with powder, the flame may singe the hair or clothing. If discharged quite hard up to the body, the edges of the wound are freely lacerated, ecchymosed, and burnt. Smokeless powder will not cause blackening of the skin. The absence of scorching, or marks made round the wound by the half-burnt powder, allows of the assumption that the shot must have come from some distance—rather more than four feet. The absence of any of the above, however, is not an absolute proof that the shot has come from a distance.
There is no means of deciding, from an examination of a pistol or gun, when the weapon was last used. In all cases, medical men, unless sportsmen and familiar with firearms, should hand over the weapon to a gamekeeper or gunsmith, and not attempt to give an opinion on matters about which they know nothing. The following may be of use to students for examination purposes, but for nothing else: Among the products formed when gunpowder is exploded is the sulphide of potassium, but if exposed to the air some portion of this substance is converted into the sulphate of potash. If, then, the gun-barrel be washed out with distilled water, and the washings filtered, and, on the addition of a solution of acetate of lead, a black precipitate of sulphide of lead be formed, this is supposed to point to recent use; if, on the other hand, a white precipitate of sulphate of lead forms, to the use of the weapon at some more distant date than the period alleged.
CHAPTER VI
BLOOD-STAINS
It is important in medico-legal investigations to determine the nature of stains found on clothes, weapons, articles of furniture, &c. In the case of blood-stains note should be made of their incidence upon the body or in its vicinity. Blood-stains may vary in their character, incidence, and magnitude, as sprays, spirts, or jets, smears of various forms, or pools of blood.
Notes should be made of the relation of the direction of a spray of blood to the position of a wounded body when found. A plan with the position of the stains should be sketched upon the spot, and measurements taken carefully.