Institute, and after eighteen months' hard work he
discovered a process of fermentation by which a large amount of fusel
oil can be obtained from any starchy stuff. Hitherto the aim in
fermentation and distillation had been to obtain as small a proportion
of fusel as possible, for fusel oil is a mixture of the heavier
alcohols, all of them more poisonous and malodorous than common alcohol.
But here, as has often happened in the history of industrial chemistry,
the by-product turned out to be more valuable than the product. From
fusel oil by the use of chlorine isoprene can be prepared, so the chain
was complete.

But meanwhile the Germans had been making equal progress. In 1905 Prof.
Karl Harries, of Berlin, found out the name of the caoutchouc molecule.
This discovery was to the chemists what the architect's plan of a house
is to the builder. They knew then what they were trying to construct
and could go about their task intelligently.

Mark Twain said that he could understand something about how astronomers
could measure the distance of the planets, calculate their weights and
so forth, but he never could see how they could find out their names
even with the largest telescopes. This is a joke in astronomy but it
is not in chemistry. For when the chemist finds out the structure
of a compound he gives it a name which means that. The stuff came
to be called "caoutchouc," because that was the way the Spaniards
of Columbus's time caught the Indian word "cahuchu." When
Dr. Priestley called it "India rubber" he told merely where it
came from and what it was good for. But when Harries named it
"1-5-dimethyl-cyclo-octadien-1-5" any chemist could draw a picture of it
and give a guess as to how it could be made. Even a person without any
knowledge of chemistry can get the main point of it by merely looking at
this diagram:

C C C---C
|| || || |
C--C C C--C C
| | --> | |
C C--C C C--C
|| || | ||
C C C---C

[Illustration: isoprene _turns into_ caoutchouc]

I have dropped the 16 H's or hydrogen atoms of the formula for
simplicity's sake. They simply hook on wherever they can. You will see
that the isoprene consists of a chain of four carbon atoms (represented
by the C's) with an extra carbon on the side. In the transformation of
this colorless liquid into soft rubber two of the double