to circulate, is not immediately
dependent upon extrinsic influences. Death is usually more immediately
due to failure of respiration than to failure of circulation, for the
heart often continues beating for a time after respiration has ceased.
Thus, in cases of drowning and suffocation, by means of artificial
respiration in which air is passively taken into and expelled from the
lungs, giving oxygen to the blood, the heart may continue to beat and
the circulation continue for hours after all evident signs of life and
all sensation has ceased.

By this general death is meant the death of the organism as a whole,
but all parts of the body do not die at the same time. The muscles and
nerves may react, the heart may be kept beating, and organs of the
body when removed and supplied with blood will continue to function.
Certain tissues die early, and the first to succumb to the lack of
oxygenated blood are the nerve cells of the brain. If respiration and
circulation have ceased for as short a time as twelve minutes, life
ceases in certain of these cells and cannot be restored. This is again
an example of the greater vulnerability of the more highly
differentiated structure in which all other forms of cell activity are
subordinated to function. There are, however, pretty well
authenticated cases of resuscitation after immersion in water for a
longer period than twelve minutes, but these cases have not been
carefully timed, and time under such conditions may seem longer than
it actually is; and there is, moreover, the possibility of a slight
gaseous interchange between the blood and the water in the lungs, as
in the case of the fish which uses the water for an oxygen supply as
the mammal does the air. There are also examples of apparent death or
trances which have lasted longer, and the cases of fakirs who have
been buried for prolonged periods and again restored to life. In these
conditions, however, all the activities of the body are reduced to the
utmost, and respiration and circulation, so feeble as to be
imperceptible to ordinary observation, suffice to keep the cells
living.

With the cessation of life the body is subject to the unmodified
action of its physical environment. There is no further production of
heat and the body takes the temperature of the surroundings. The only
exceptions are rare cases in which such active chemical changes take
place in the dead body that heat is generated by chemical action. At a
va