er mills are being worked up successfully into
industrial alcohol.

The rapidly approaching exhaustion of our oil fields which the war has
accelerated leads us to look around to see what we can get to take the
place of gasoline. One of the most promising of the suggested
substitutes is alcohol. The United States is exceptionally rich in
mineral oil, but some countries, for instance England, Germany, France
and Australia, have little or none. The Australian Advisory Council of
Science, called to consider the problem, recommends alcohol for
stationary engines and motor cars. Alcohol has the disadvantage of
being less volatile than gasoline so it is hard to start up the engine
from the cold. But the lower volatility and ignition point of alcohol
are an advantage in that it can be put under a pressure of 150 pounds to
the square inch. A pound of gasoline contains fifty per cent. more
potential energy than a pound of alcohol, but since the alcohol vapor
can be put under twice the compression of the gasoline and requires only
one-third the amount of air, the thermal efficiency of an alcohol engine
may be fifty per cent. higher than that of a gasoline engine. Alcohol
also has several other conveniences that can count in its favor. In the
case of incomplete combustion the cylinders are less likely to be
clogged with carbon and the escaping gases do not have the offensive
odor of the gasoline smoke. Alcohol does not ignite so easily as
gasoline and the fire is more readily put out, for water thrown upon
blazing alcohol dilutes it and puts out the flame while gasoline floats
on water and the fire is spread by it. It is possible to increase the
inflammability of alcohol by mixing with it some hydrocarbon such as
gasoline, benzene or acetylene. In the Taylor-White process the vapor
from low-grade alcohol containing 17 per cent. water is passed over
calcium carbide. This takes out the water and adds acetylene gas, making
a suitable mixture for an internal combustion engine.

Alcohol can be made from anything of a starchy, sugary or woody nature,
that is, from the main substance of all vegetation. If we start with
wood (cellulose) we convert it first into sugar (glucose) and, of
course, we could stop here and use it for food instead of carrying it
on into alcohol. This provides one factor of our food, the carbohydrate,
but by growing the yeast plants on glucose and feeding them with
nitrates made from the air we can get the protein