rt of the body, the teeth
must be exercised in order to be properly preserved. Our foods are so
frequently macerated to a fine consistency and they are so often cooked
to a mush before they are eaten, that the teeth have little to do. They
decay and become soft or brittle because of lack of use.

It is necessary to give the teeth a reasonable amount of regular use.
Cultivate the habit of eating zwieback, hard crackers or other hard
food substances that require real vigorous chewing. If this is
difficult, then make a habit of exercising the teeth in some way. The
idea suggested in the illustrations accompanying this chapter will be
found of value, though any method can be recommended that serves the
same purpose. Do not, however, depend upon the chewing of gum for
hours each day as a means of exercising the teeth. Chewing a hard gum
for a few minutes after a meal might be of advantage, but continual gum-
chewing wastes and weakens the digestive elements of the saliva. In
other words, if you sit down to a meal after chewing gum for two or
three hours, the saliva that you mix with your food will not have the
normal digestive elements. One might say that the "strength" of the
saliva has been lost while chewing gum.

If your teeth are decayed the offending members should be removed or the
cavities filled. It is always wise to retain every tooth you can until
extraction is practically compulsory. Decayed teeth should be filled
promptly. As long as a tooth can be filled it should not be extracted.
A good dentist should be consulted at frequent intervals.

If tartar has collected on the teeth, it should be removed by a
competent dentist. One good method of keeping the teeth free from tartar
is to rub the gums and teeth daily with table salt containing
considerable grit. Dampen the finger, place a quantity of table salt
thereon and then rub the teeth where they meet the gums. Make the
process sufficiently vigorous to rub off any tartar that may have
accumulated. The mouth should be rinsed with moderately warm water
immediately after this process to remove the salt. Any good tooth wash
that is sold in the form of paste can be used instead of salt for
this same purpose. This rubbing process is of more value to strengthen
the gums and to cleanse the teeth than brushing the teeth with an
ordinary tooth brush.

Tooth brushes, however, are valuable and should be used morning and
evening. In caring for th