ood of all kinds is
consumed in cold than in warm climates. The accounts by travelers of the
quantity of food used by the inhabitants of the frigid zone are almost
beyond belief. A Russian admiral gives an instance of a man who, in his
presence, ate at a single meal 28 pounds of rice and butter. Dr. Hayes,
the Arctic traveler, states from personal observation that the daily
ration of the Eskimos is 12 to 15 pounds of meat. With the thermometer
ranging from 60 to 70 degrees F. below zero, there was a persistent
craving for strong animal diet, especially fatty foods.[24]

[Illustration: Fig. 63.--Lymphatics and Lymphatic Glands of the Axilla.]

The intense cold makes such a drain upon the heat-producing power of the
body that only food containing the largest proportion of carbon is capable
of making up for the loss. In tropical countries, on the other hand, the
natives crave and subsist mainly upon fruits and vegetables.

165. The Kinds of Food Required. An appetite for plain, well-cooked
food is a safe guide to follow. Every person in good health, taking a
moderate amount of daily exercise, should have a keen appetite for three
meals a day and enjoy them. Food should be both nutritious and digestible.
It is nutritious in proportion to the amount of material it furnishes for
the nourishment of the tissues. It is digestible in a greater or less
degree in respect to the readiness with which it yields to the action of
the digestive fluids, and is prepared to be taken up by the blood. This
digestibility depends partly upon the nature of the food in its raw state,
partly upon the effect produced upon it by cooking, and to some extent
upon its admixture with other foods. Certain foods, as the vegetable
albumens, are both nutritious and digestible. A hard-working man may grow
strong and maintain vigorous health on most of them, even if deprived of
animal food.

While it is true that the vegetable albumens furnish all that is really
needed for the bodily health, animal food of some kind is an economical
and useful addition to the diet. Races of men who endure prolonged
physical exertion have discovered for themselves, without the teaching of
science, the great value of meat. Hence the common custom of eating meat
with bread and vegetables is a sound one. It is undoubtedly true that the
people of this country, as a rule, eat meat too often and too much at a
time. The judicious admixture of different classes of foods greatly aids