Aids to Forensic Medicine and Toxicology | Page 8

long life has been extinct. The following, however,
do:
=Cooling of the Body.=--The average internal temperature of the body
is from 98° to 100° F. The time taken in cooling is from fifteen to
twenty hours, but it may be modified by the kind of death, the age of
the person, the presence or absence of clothing on the body, the

surrounding temperature, and the stillness or otherwise of the air about
the body. Still, the body, other things being equal, may be said to be
quite cold in about twelve hours.
=Hypostasis= or =post-mortem staining= is due to the settling down of
the blood in the most dependent parts of the body while the body is
cooling. It is a sure sign of death, and occurs in all forms of death, even
in that due to hæmorrhage, although not so marked in degree.
Post-mortem staining (cadaveric lividity) begins to appear in from eight
to twelve hours after death, and its position on the body will help to
determine the length of time the body has lain in the position in which
it was found. The staining is of a dull red or slaty blue colour. It must
be distinguished from ecchymosis the result of a bruise, by making an
incision into the part; in the case of hypostasis a few small bloody
points of divided arteries will be seen, in the case of ecchymosis the
subcutaneous tissues are infiltrated with blood-clot. Internally,
hypostasis must not be mistaken for congestion of the brain or lungs, or
the results of inflammation of the intestines. If the intestine is pulled
straight, inflammatory redness is continuous, hypostasis is
disconnected. About the neck hypostasis must not be mistaken for the
mark of a cord or other ligature. When the blood is of a bright red
colour after death (as happens in poisoning by CO or HCN, or in death
from cold), the hypostasis is bright red also.
=Cadaveric Rigidity--Rigor Mortis.=--For some time after death the
muscles continue to contract under stimuli. When this irritability
ceases--and it seldom exceeds two hours--rigidity and hardening sets in,
and in all cases precedes putrefaction. It is caused by the coagulation of
the muscle plasma. It commences in the muscles of the back of the
neck and lower jaw, and then passes into the muscles of the face, front
of the neck, chest, upper extremities, and lastly to the lower
extremities.
It has been noticed in the new-born infant, as well as in the foetus. It
lasts from sixteen to twenty hours or more. In lingering diseases, after
violent exertion, and in warm climates, it sets in quickly, and
disappears in two or three hours; in those who are in perfect health and

die from accident or asphyxia, it may not come on until from ten to
twenty-four hours, and may last three or four days. After death from
convulsions or strychnine-poisoning, the body may pass at once into
rigor mortis. Rigor mortis must be distinguished from cadaveric spasm
or the death clutch; in the former, articles in the hands are readily
removable, in the latter this is not the case. In tetanic spasm the limbs
when bent return to their former position; not so in rigor mortis.
=Putrefaction= appears in from one to three days after death, as a
greenish-blue discoloration of the abdomen; in the drowned, over the
head and face. This increases, becomes darker and more general, a
strong putrefactive odour is developed, the thorax and abdomen
become distended with gas, and the epidermis peels off. The muscles
then become pulpy, and assume a dark greenish colour, the whole body
at length becoming changed into a soft, semi-fluid mass. The organ
first showing the putrefactive change is the trachea; that which resists
putrefaction longest is the uterus. These putrefactive changes are
modified by the fat or lean condition of the body, the temperature
(putrefaction taking place more rapidly in summer than in winter),
access of air, the period, place, mode of interment, age, etc. Bodies
which remain in water putrefy more slowly than those in air.
=Saponification.=--In bodies which are very fat and have lain in water
or moist soil for from one to three years this process takes place, the fat
uniting with the ammonia given off by the decomposition to form
adipocere. This consists of a margarate or stearate of ammonium with
lime, oxide of iron, potash, certain fatty acids, and a yellowish odorous
matter. It has a fatty, unctuous feel, is either pure white or pale yellow,
with an odour of decayed cheese. Small portions of the body may show
signs of this change in six weeks.
=Post-Mortem Examination.=--Never make an autopsy in criminal
cases without a written order from the coroner or Procurator Fiscal. If
authorized, however, first have the body identified, then photographed