ns in the
chemist's laboratory. These organic compounds form a series beginning
with such simple bodies as carbonic acid (CO_{2}), water (H_{2}O), and
ammonia (NH_{3}), and passing up through a large number of members of
greater and greater complexity, all composed, however, chiefly of the
elements carbon, oxygen, hydrogen, and nitrogen. Our chemists found that
starting with simple substances they could, by proper means, combine
them into molecules of greater complexity, and in so doing could make
many of the compounds that had hitherto been produced only as a result
of living activities. For example, urea, formic acid, indigo, and many
other bodies, hitherto produced only by animals and plants, were easily
produced by the chemist by purely chemical methods. Now when protoplasm
had been discovered as the "physical basis of life," and, when it was
further conceived that this substance is a proteid related to albumens,
it was inevitable that a theory should arise which found the explanation
of life in accordance with simple chemical laws.

If, as chemists and biologists then believe, protoplasm is a compound
which stands at the head of the organic series, and if, as is the fact,
chemists are each year succeeding in making higher and higher members of
the series, it is an easy assumption that some day they will be able to
make the highest member of the series. Further, it is a well-known fact
that simple chemical compounds have simple physical properties, while
the higher ones have more varied properties. Water has the property of
being liquid at certain temperatures and solid at others, and of
dividing into small particles (i.e., dissolving) certain bodies brought
in contact with it. The higher compound albumen has, however, a great
number of properties and possibilities of combination far beyond those
of water. Now if the properties increase in complexity with the
complexity of the compound, it is again an easy assumption that when we
reach a compound as complex as protoplasm, it will have properties as
complex as those of the simple life substance. Nor was this such a very
wild hypothesis. After all, the fundamental life activities may all be
traced to the simple oxidation of food, for this results in movement,
assimilation, and growth, and the result of growth is reproduction. It
was therefore only necessary for our biological chemists to suppose that
their chemical compound protoplasm possessed the power of causing
ce