1. Nature of the external apertures.—The apertures of entry and exit in uncomplicated cases are very insignificant, but the size naturally varies slightly with that of the special form of bullet concerned. As will be shown moreover, the difference in size is the only real distinguishing characteristic in many cases between wounds produced by the modern bullet of small calibre and those resulting from the use of the older and larger projectiles of conical form. I have been very much struck on looking over my diagrams of entry, and especially exit, wounds to find that they reproduce in miniature most of those figured in the History of the War of the Rebellion; some of these diagrams are reproduced in this chapter.
Aperture of entry.—The typical wound of entry with a normal undeformed bullet varies in appearance according to whether the projectile has impinged at a right angle or at increasing degrees of obliquity, or again, to whether the skin is supported by soft tissues alone, or on those of a more resistent nature such as bone or cartilage.
Fig. 16.—Mauser Entry and Exit Wounds.
A, entry in buttock; circular opening filled with clot and crossed by a tag of tissue. B, exit in epigastrium near mid-line; irregular slit form, with well-marked prominence. Specimens hardened in formalin immediately after death; the resulting contraction has slightly exaggerated the irregularity of outline of the entry wound
Fig. 17.
Gutter Wound of outer aspect of shoulder, caused by a normal Mauser, which subsequently perforated a man's leg. At the central part the gutter was 3/4 in. deep a few days after the injury
When the bullet impinges at a right angle the wound is circular, with more or less depressed margins, and of a diameter, corresponding to the size of the bullet occasioning it, from a quarter to a third of an inch. The description 'punched out' has been sometimes applied to it, but it would be more correct to reverse the term to 'punched in,' since the appearance is really most nearly simulated by a hole resulting from the driving of a solid punch into a soft structure enveloped in a denser covering. The loss of substance, moreover, in the primary stage is not actually so great as appears to be the case, fragments of contused tissue from the margin being turned into the opening of the wound track. The true margin therefore is not sharp cut, and the nature of the line differs somewhat according to the structure of the skin in the locality impinged upon. Thus the granular scalp and the comparatively homogeneous skin of the anterior abdominal wall will furnish good examples of the nature of the slight difference in appearance. From the first the margin is also often somewhat discoloured by a metallic stain, similar to that seen when a bullet is fired through a paper book. This ring is, however, narrow, and not likely to be noticeable when the bullet has passed through the clothing. In any case it is subsequently obscured by the development of a narrow ring of discoloration due to the contusion. This latter varies in width, and still later a halo of ecchymosis half an inch or more in diameter surrounds the original wound.
