Can the appearance of a bruise be produced after death?—It is possible that the appearance of a bruise inflicted during life may be produced within two hours after death, and in some rare cases even after the lapse of three hours and a quarter (Christison); but these ecchymoses are limited in extent, and when large are due to a rupture in a vein which can be readily ascertained. The experiments of the late Sir Robert Christison, relating to this question, are detailed in the Edinburgh Medical and Surgical Journal, vol. xxxi. The amount of violence required after death to produce appearances like those made before death is such as would seldom, if ever, be inflicted on a corpse, and, therefore, where we find a well-marked bruise we ought to infer that it was made before death.
The following table, compiled from the experiments of Christison, may assist the diagnosis:
| During Life. | After Death. |
| 1. Swelling of the part. | 1. No swelling. |
| 2. Coagulation of the blood | 2. No such appearance, unless |
| effused into the adjacent | there is a rupture of a large |
| cellular tissue, with or | vessel in the neighbourhood |
| without tumefaction. | of loose cellular tissue. |
| 3. Incorporation of blood | 3. No such appearance produced |
| with the whole thickness | by a blow after death. |
| of the true skin, rendering | |
| it black instead of white. |
N.B.—Extensive effusion may occur without affecting the skin, but when the skin is so affected Christison thought it decisive of ante-mortem injury.
The Size and Form of a Bruise should be noted.
Why?
1. In Hanging and Strangulation.—The mark due to pressure of the cord on the neck in hanging runs obliquely round the neck; in strangulation, the mark encircles the neck. The mark is frequently interrupted, and may present very varied appearances in different parts of the neck. The mark of the knot may be found under the chin.
2. In Throttling.—The pressure exerted on the throat of the deceased by the fingers of his assailant may leave marks which may point to the means used to cause death.
3. In other Cases of Death by Violence.—The impression made by the weapon used may lead to the identification of the murderer. The marks left by the wards of a large door-key once led to the identification of the assailant.