Biological science has hunted the secret of vitality like a detective;
and it has done some famous work; but it has not yet unraveled the
mystery. It knows well the part played by carbon, oxygen, and hydrogen
in organic chemistry, that without water and carbon dioxide there could
be no life; it knows the part played by light, air, heat, gravity,
osmosis, chemical affinity, and all the hundreds or thousands of organic
compounds; it knows the part played by what are called the enzymes, or
ferments, in all living bodies, but it does not know the secret of these
ferments; it knows the part played by colloids, or jelly-like compounds,
that there is no living body without colloids, though there are colloid
bodies that are not living; it knows the part played by oxidation, that
without it a living body ceases to function, though everywhere all about
us is oxidation without life; it knows the part played by chlorophyll in
the vegetable kingdom, and yet how chlorophyll works such magic upon the
sun's rays, using the solar energy to fix the carbon of carbonic acid in
the air, and thereby storing this energy as it is stored in wood and
coal and in much of the food we consume, is a mystery. Chemistry cannot
repeat the process in its laboratories. The fungi do not possess this
wonderful chlorophyllian power, and hence cannot use the sunbeam to
snatch their carbon from the air; they must get it from decomposed
vegetable matter; they feed, as the animals do, upon elements that have
gone through the cycle of vegetable life. The secret of vegetable life,
then, is in the green substance of the leaf where science is powerless
to unlock it. Conjure with the elements as it may, it cannot produce the
least speck of living matter. It can by synthesis produce many of the
organic compounds, but only from matter that has already been through
the organic cycle. It has lately produced rubber, but from other
products of vegetable life.
As soon as the four principal elements, carbon, oxygen, hydrogen, and
nitrogen, that make up the living body, have entered the world of living
matter, their activities and possible combinations enormously increase;
they enter into new relations with one another and form compounds of
great variety and complexity, characterized by the instability which
life requires. The organic compounds are vastly more sensitive to light
and heat and air than are the same elements in the inorganic world. What
has happened to them? Chemistry cannot tell us. Oxidation, which is only
slow combustion, is the main source of energy in the body, as it is in
the steam-engine. The storing of the solar energy, which occurs only in
the vegetable, is by a process of reduction, that is, the separation of
the carbon and oxygen in carbonic acid and water. The chemical reactions
which liberate energy in the body are slow; in dead matter they are
rapid and violent, or explosive and destructive. It is the chemistry in
the leaf of the plant that diverts or draws the solar energy into the
stream of life, and how it does it is a mystery.
The scientific explanations of life phenomena are all after the fact;
they do not account for the fact; they start with the ready-made
organism and then reduce its activities and processes to their physical
equivalents. Vitality is given, and then the vital processes are fitted
into mechanical and chemical concepts, or into moulds derived from inert
matter--not a difficult thing to do, but no more an explanation of the
mystery of vitality than a painting or a marble bust of Tyndall would be
an explanation of that great scientist.
All Professor Loeb's experiments and criticisms throw light upon the
life processes, or upon the factors that take part in them, but not upon
the secret of the genesis of the processes themselves. Amid all the
activities of his mechanical and chemical factors, there is ever present
a factor which he ignores, which his analytical method cannot seize;
namely, what Verworn calls "the specific energy of living substance."
Without this, chemism and mechanism would work together to quite other
ends. The water in the wave, and the laws that govern it, do not differ
at all from the water and its laws that surround it; but unless one
takes into account the force that makes the wave, an analysis of the
phenomena will leave one where he began.
Professor Le Dantec leaves the subject where he took it up, with the
origin of life and the life processes unaccounted for. His work is a
description, and not an explanation. All our ideas about vitality, or an
unknown factor in the organic world, he calls "mystic" and unscientific.
A sharp line of demarcation between living and non-living bodies is not
permissible. This, he says, is the anthropomorphic error which puts some
mysterious quality or force in all bodies considered to be living. To Le
Dantec, the difference between the quick and the dead is of the same
order as the difference which exists between two chemical compounds--for
example, as that which exists between alcohol and an aldehyde, a liquid
that has two less atoms of hydrogen in its composition. Modify your
chemistry a little, add or subtract an atom or two, more or less, of
this or that gas, and dead matter thrills into life, or living matter
sinks to the inert. In other words, life is the gift of chemistry, its
particular essence is of the chemical order--a bold inference from the
fact that there is no life without chemical reactions, no life without
oxidation. Yet chemical reactions in the laboratory cannot produce life.
With Le Dantec, biology, like geology and astronomy, is only applied
mechanics and chemistry.