with the material which forms the chief part of our own muscles, which
forms the chief part of our own blood, which forms the chief part of
the white of the egg; that, in fact, although this little organism is a
plant, and nothing but a plant, yet that its active living contents
contain a substance which is called "protein," which is of the same
nature as the substance which forms the foundation of every animal
organism whatever.

Now we come next to the question of the analysis of the products, of
that which is produced during the process of fermentation. So far back
as the beginning of the 16th century, in the times of transition
between the old alchemy and the modern chemistry, there was a
remarkable man, Von Helmont, a Dutchman, who saw the difference between
the air which comes out of a vat where something is fermenting and
common air. He was the man who invented the term "gas," and he called
this kind of gas "gas silvestre"--so to speak gas that is wild, and
lives in out of the way places--having in his mind the identity of this
particular kind of air with that which is found in some caves and
cellars. Then, the gradual process of investigation going on, it was
discovered that this substance, then called "fixed air," was a poisonous
gas, and it was finally identified with that kind of gas which is
obtained by burning charcoal in the air, which is called "carbonic
acid." Then the substance alcohol was subjected to examination, and it
was found to be a combination of carbon, and hydrogen, and oxygen. Then
the sugar which was contained in the fermenting liquid was examined and
that was found to contain the three elements carbon, hydrogen, and
oxygen. So that it was clear there were in sugar the fundamental
elements which are contained in the carbonic acid, and in the alcohol.
And then came that great chemist Lavoisier, and he examined into the
subject carefully, and possessed with that brilliant thought of his