124 MEDICAL JURISPRUDENCE
may be present before death in uraemia, narcotic poisoning and cholera,
while the cornea may retain its transparency for some time after death from
apoplexy and from poisoning by hydrocyanic acid or carbon monoxide. The
pupils are usually moderately dilated and are insensible to strong light, but
react to solutions of atropme or eserine probably for an hour after death,
but not longer. The pupils also change their form, and become oval, tri-
angular or polygonal, when pressure is applied by the fingers on two or more
sides of the eyeballs of a really dead person, but they retain their round
form in a living person, or in one who is apparently dead.10
3. CHANGES IN THE SKIN
After death the skin of the whole body assumes a pale and ashy-white
appearance especially in fair bodies, and loses its elasticity ; ignce incised
wounds will not gape if caused after death. But the edges of ulcers and
wounds caused during life retain their red or blue colour after death, and
so do ecchymoses. Further, the icteric hue produced in jaundice or phos-
phorus poisoning and tattoo-marks are not at all affected by this change.
4. COOLING OF THE BODY
After death the body commences to lose its animal heat and gradually
attains the same temperature as that of its surrounding medium. But it
must be borne in mind that this loss of heat cannot be considered as a cer-
tain sign of death until the body has lost 15 to 20 degrees of the normal heat,
viz. S8.43F.3 for a rectal temperature of 90° to 94°F. may be observed in the
algid state of cholera and severe cases of collapse, and a much lower tempe-
rature of 75: or 76°F. may be noted in cases of long exposure to cold.
The rate of cooling is not uniform, but it is almost proportional to the
difference in temperature between the body and its surroundings. The rate
is, therefore, rapid during the first few hours after death, and is slow after-
wards, as the temperature of the body comes nearer to that of its surround-
ings. Simpsonll has found from investigations on dead bodies that under
average conditions a clothed body in a temperate country loses about 2.5°F. |
per hour for the first six hours, and 1.5 to 2°F. for the next six hours. Thus, ,
the_ whole surface of the body takes about twelve hours and the internal
organs take twenty to twenty-four hours to reach the temperature of the
environment, but much less time in a tropical country like India. From
observations 12 made in 1902 at the famine hospital in Bombay, where the
temperature is seldom above 98.6°F., it was found that, in those cases where
the body temperature was normal at the time of death, the average rate in
the fall of temperature during the first two hours was one-half of the dif-
ference between that of the body and that of the air. During the next two
hours the temperature fell at half this rate, and during the next two hours,
at half the last mentioned rate or about a quarter of the initial rate. There-
after the cooling took place at a much slower rate, the body attaining the
temperature of the air in from twelve to fifteen hours after death. In one
case in which the temperature recorded at death was 105.8°F., the body
temperature came down to that of the air and then rose 13 degrees above the
air-temperature in thirteen hours and a half after death.
The rate of cooling of the body may be influenced by such causes as age,f
condition of the body, manner of death, and surroundings of the body.
Age.—The bodies of young and middle-aged persons cool more slowly
than the bodies of children and old people.
10. L. Tonelli, II Policlin, 1932, sez. prat., XXXIX, pp. 205-210; Med.-Leg. and
Criminolog. Review, April 1933, p. 132.
11. Science Progress, Oct. 1946, p. 713; Lancet, Nov. 23, 1946, p. 761.
12. Collis Barry, Legal Med., Vol. H, Ed. II, p. 2.