the best source of supply is the carbohydrates, that is, the
sugars and starches. The fats are more concentrated but are more
expensive and less easily assimilable. The proteins are also more
expensive and their decomposition products are more apt to clog up the
system. Common sugar is almost an ideal food. Cheap, clean, white,
portable, imperishable, unadulterated, pleasant-tasting, germ-free,
highly nutritious, completely soluble, altogether digestible, easily
assimilable, requires no cooking and leaves no residue. Its only fault
is its perfection. It is so pure that a man cannot live on it. Four
square lumps give one hundred calories of energy. But twenty-five or
thirty-five times that amount would not constitute a day's ration, in
fact one would ultimately starve on such fare. It would be like
supplying an army with an abundance of powder but neglecting to provide
any bullets, clothing or food. To make sugar the sole food is
impossible. To make it the main food is unwise. It is quite proper for
man to separate out the distinct ingredients of natural products--to
extract the butter from the milk, the casein from the cheese, the sugar
from the cane--but he must not forget to combine them again at each meal
with the other essential foodstuffs in their proper proportion.

[Illustration: THE RIVAL SUGARS The sugar beet of the north has become
a close rival of the sugar cane of the south]

[Illustration: INTERIOR OF A SUGAR MILL SHOWING THE MACHINERY FOR
CRUSHING CANE TO EXTRACT THE JUICE]

[Illustration: Courtesy of American Sugar Refinery Co.

VACUUM PANS OF THE AMERICAN SUGAR REFINERY COMPANY

In these air-tight vats the water is boiled off from the cane juice
under diminished atmospheric pressure until the sugar crystallizes out]

Sugar is not a synthetic product and the business of the chemist has
been merely to extract and purify it. But this is not so simple as it
seems and every sugar factory has had to have its chemist. He has
analyzed every mother beet for a hundred years. He has watched every
step of the process from the cane to the crystal lest the sucrose should
invert to the less sweet and non-crystallizable glucose. He has tested
with polarized light every shipment of sugar that has passed through the
custom house, much to the mystification of congressmen who have often
wondered at the money and argumentation expended in a tariff discussion
over the question of the precise angle of rotation of the pla