the micro-organisms which bring about putrefaction; absence of air soon
arrests the changes: this is seen in bodies hermetically sealed in
lead coffins, which remain unchanged for a long period of time. Moist
rather than dry air favors putrefaction by lessening evaporation. Air
in motion retards while still air favors the change.
It is to be remembered that a body decomposes more rapidly in air than
in water or after burial. Given similar temperatures, the amount of
putrefaction observed in a body dead one week and exposed to the air
will about correspond to one submerged in water for two weeks or buried
in a deep grave for eight weeks.