ntal tissue used up in the ordinary processes of mental work is not
great enough to call for any large diminution of the supply of blood to
other parts of the body.

_Consumption of water._

A move in the right direction to-day undoubtedly is the tendency to
increase the quantity of water to drink. The body is nine-tenths per
cent water, and while a large part of the water in the tissues is made
chemically by combinations of hydrogen and oxygen, there must be a
constant replenishing of the liquids of the body.

The ordinary person ought to drink, or consume with his food in some
way, at least two quarts of water a day, and many difficulties with the
liver, kidneys, and other organs would be avoided if this amount of
water daily were imbibed. Probably the contention that water should not
be taken at meals is not particularly tenable except as the continual
swallowing of water increases the tendency to swallow food without
chewing, a childish habit sure to lead to distress later. But, to eat
one's dinner or part of one's dinner and then drink a glass of water
cannot reasonably be assumed to interfere with any digestive process. It
is quite likely, in fact, that the greater dilution of the mass in the
stomach will tend to easier absorption later on.

_Condiments and drinks._

There are certain kinds of foods which, though not strictly included in
the four elements of food already named, yet are so common as to deserve
special mention. Chief among these are the condiments and drinks,
particularly coffee and tea. So far as the nutritive value of such
materials as salt and pepper, vinegar or spices, goes, they are
practically negligible, and yet, undoubtedly, these flavors play an
important part in the suggestion of pleasure and therefore in the
excitement leading to the excretion of the digestive juices. If one ate
salt pork and boiled potatoes always, eating would be a tiresome affair,
and it is quite likely that such a sameness of food would fail to
excite subsequent digestion, merely from the monotony of the affair.
Salt, however, has a particular role in that the human body craves this
mineral, and, while its exact value in the body is not clearly known, a
certain amount of it must always be provided. The wild tribes of Africa,
for instance, away from deposits of salt consider it their most valuable
possession and will go to great lengths to procure it. Animals, in the
same way, go great distances for a supply of sa