HOW THE BODY OF ANIMALS IS CONSTANTLY DYING AND BEING RENEWED.

The body of any thing whatever that takes nourishment constantly
dies and is constantly renewed; because nourishment can only enter
into places where the former nourishment has expired, and if it has
expired it no longer has life. And if you do not supply nourishment
equal to the nourishment which is gone, life will fail in vigour,
and if you take away this nourishment, the life is entirely
destroyed. But if you restore as much is destroyed day by day, then
as much of the life is renewed as is consumed, just as the flame of
the candle is fed by the nourishment afforded by the liquid of this
candle, which flame continually with a rapid supply restores to it
from below as much as is consumed in dying above: and from a
brilliant light is converted in dying into murky smoke; and this
death is continuous, as the smoke is continuous; and the continuance
of the smoke is equal to the continuance of the nourishment, and in
the same instant all the flame is dead and all regenerated,
simultaneously with the movement of its own nourishment.