Period of the Occurrence of Death.
As already indicated, death may occur from direct causes during the first forty-eight hours after the infliction of the burn, or may take place during a period extending from the second day to the fifth or even the sixth week. In the great majority of cases the fatal result occurs during the first five or six days. In some instances it may be important to establish the fact as to how long after the infliction of the burn the person may have survived.
Inflammation and suppuration would not ordinarily begin until about the third day, hence the existence of this condition would indicate that the person had probably lived two days or more; and the state of advancement of these processes would afford some further evidence. The existence of intestinal inflammations and ulcerations, which require some days for their appearance and development, would also give some indication of the probable time elapsing.
WAS THE BURN ANTE MORTEM OR POST MORTEM?
In describing the anatomical characters of a burn occurring during life, vesication, the formation of blisters, is regarded as a marked symptom.
While it is not an invariable result in a burn of the living body, it is so constant as to become one of the most important factors in answering the question as to the ante-or post-mortem infliction of the burn. Where the burn has been caused by a scalding fluid, or by burning of the clothing, or the direct application of flame, blisters are more likely to occur than where contact with a highly heated body has taken place. In the formation of a blister the cuticle is raised from the derma or true skin by the effusion of a highly albuminous serum, and the surrounding skin is of a bright or coppery red color. The time of the appearance of such a blister is not fixed. It may occur almost immediately or may not do so for several hours, an interval sufficiently long for death to occur from shock. It must be remembered that a burn inflicted in a condition of great depression of the vital powers with insensibility may be followed by no vesication or redness, but upon reaction and return of sensation both redness and blisters may appear (Case 17). In the absence of blisters, therefore, it cannot be decided that for this reason the burn was post mortem. If from a blister formed on the living body the cuticle be carefully removed, the site of the blister will present an intensely reddened base. In the dead body, if the cuticle be removed, no red base appears, but the surface of the blister becomes dry and of a grayish color.
On the other hand, if the presence of blisters is noted, can it be concluded that the burn was ante mortem? While their presence affords reason for an affirmative answer, careful examination of the blisters as to their character and contents must be made in order to decide; the presence of apparent blisters is not alone sufficient (Cases 20, 18; Plate II.).
Elaborate experiments have been made in order to decide the possibility of producing blisters post mortem.
Leuret,[711] in experiments upon dropsical subjects twenty-four hours after death, shows the possibility of raising a blister post-mortem, but one which can be distinguished from one of ante-mortem production, in that it contains a reddish serum very slightly albuminous. He urges extreme care in deciding this question.
Christison[712] found it impossible to produce a blister a few hours after death. In a patient unconscious from narcotic poison, heat applied four hours before death produced a blister and a red line was formed around the burns. In the burns produced half an hour after death, in the same patient, blisters formed in two places only, and these were covered by dry skin and contained air. No redness appeared around them.