force within and a force
without, but the force within does all the struggling. The air does not
struggle to get into the lungs, nor the lime and iron to get into our
blood. The body struggles to digest and assimilate the food; the
chlorophyll in the leaf struggles to store up the solar energy. The
environment is unaware of the organism; the light is indifferent to the
sensitized plate of the photographer. Something in the seed we plant
avails itself of the heat and the moisture. The relation is not that of
a thermometer or hygrometer to the warmth and moisture of the air; it is
a vital relation.

Life may be called an aquatic phenomenon, because there can be no life
without water. It may be called a thermal phenomenon, because there can
be no life below or above a certain degree of temperature. It may be
called a chemical phenomenon, because there can be no life without
chemical reactions. Yet none of these things define life. We may discuss
biological facts in terms of chemistry without throwing any light on the
nature of life itself. If we say the particular essence of life is
chemical, do we mean any more than that life is inseparable from
chemical reactions?

After we have mastered the chemistry of life, laid bare all its
processes, named all its transformations and transmutations, analyzed
the living cell, seen the inorganic pass into the organic, and beheld
chemical reaction, the chief priestess of this hidden rite, we shall
have to ask ourselves, Is chemistry the creator of life, or does life
create or use chemistry? These "chemical reaction complexes" in living
cells, as the biochemists call them, are they the cause of life, or only
the effect of life? We shall decide according to our temperaments or our
habits of thought.

IX

THE JOURNEYING ATOMS

I

Emerson confessed in his "Journal" that he could not read the
physicists; their works did not appeal to him. He was probably repelled
by their formulas and their mathematics. But add a touch of chemistry,
and he was interested. Chemistry leads up to life. He said he did not
think he would feel threatened or insulted if a chemist should take his
protoplasm, or mix his hydrogen, oxygen, and carbon, and make an
animalcule incontestably swimming and jumping before his eyes. It would
be only evidence of a new degree of power over matter which man had
attained to. It would all finally redound to the glory of matter itself,
which, it appears, "is impre