asm. While the
study of plants and animals was showing scientists that natural forces
would explain the origin of more complex types from simpler ones through
the law of natural selection, here in this conception of protoplasm was
a theory which promised to show how the simplest forms may have been
derived from the non-living. For an explanation of the _origin_ of life
by natural means appeared now to be a simple matter.

It required now no violent stretch of the imagination to explain the
origin of life something as follows: We know that the chemical elements
have certain affinities for each other, and will unite with each other
under proper conditions. We know that the methods of union and the
resulting compounds vary with the conditions under which the union takes
place. We know further that the elements carbon, hydrogen, oxygen, and
nitrogen have most remarkable properties, and unite to form an almost
endless series of remarkable bodies when brought into combination under
different conditions. We know that by varying the conditions the chemist
can force these elements to unite into a most extraordinary variety of
compounds with an equal variety of properties. What more natural, then,
than the assumption that under certain conditions these same elements
would unite in such a way as to form this compound protoplasm; and then,
if the ideas concerning protoplasm were correct, this body would show
the properties of protoplasm, and therefore be alive. Certainly such a
supposition was not absurd, and viewed in the light of the rapid advance
in the manufacture of organic compounds could hardly be called
improbable. Chemists beginning with simple bodies like CO_{2} and H_{2}O
were climbing the ladder, each round of which was represented by
compounds of higher complexity. At the top was protoplasm, and each year
saw our chemists nearer the top of the ladder, and thus approaching
protoplasm as their final goal. They now began to predict that only a
few more years would be required for chemists to discover the proper
conditions, and thus make protoplasm. As late as 1880 the prediction was
freely made that the next great discovery would be the manufacture of a
bit of protoplasm by artificial means, and thus in the artificial
production of life. The rapid advance in organic chemistry rendered this
prediction each year more and more probable. The ability of chemists to
manufacture chemical compounds appeared to be unlimited, and th