terminated by other organisms. In the order of nature, life destroys
life, and compounds destroy compounds. When the air and soil and water
hold no invisible living germs, organic bodies never decay. It is not
the heat that begets putrefaction, but germs in the air. Sufficient heat
kills the germs, but what disintegrates the germs and reduces them to
dust? Other still smaller organisms? and so on _ad infinitum_? Does the
sequence of life have no end? The destruction of one chemical compound
means the formation of other chemical compounds; chemical affinity
cannot be annulled, but the activity we call vital is easily arrested. A
living body can be killed, but a chemical body can only be changed into
another chemical body.

The least of living things, I repeat, holds a more profound mystery than
all our astronomy and our geology hold. It introduces us to activities
which our mathematics do not help us to deal with. Our science can
describe the processes of a living body, and name all the material
elements that enter into it, but it cannot tell us in what the peculiar
activity consists, or just what it is that differentiates living matter
from non-living. Its analysis reveals no difference. But this difference
consists in something beyond the reach of chemistry and of physics; it
is active intelligence, the power of self-direction, of self-adjustment,
of self-maintenance, of adapting means to an end. It is notorious that
the hand cannot always cover the flea; this atom has will, and knows
the road to safety. Behold what our bodies know over and above what we
know! Professor Czapek reveals to us a chemist at work in the body who
proceeds precisely like the chemist in his laboratory; they might both
have graduated at the same school. Thus the chemist in the laboratory is
accustomed to dissolve the substance which is to be used in an
experiment to react on other substances. The chemical course in living
cells is the same. All substances destined for reactions are first
dissolved. No compound is taken up in living cells before it is
dissolved. Digestion is essentially identical with dissolving or
bringing into a liquid state. On the other hand, when the chemist wishes
to preserve a living substance from chemical change, he transfers it
from a state of solution into a solid state. The chemist in the living
body does the same thing. Substances which are to be stored up, such as
starch, fat, or protein bodies, are deposited in ins