but clear water is sufficient, if used frequently and thoroughly. The
teeth should not be used in breaking nuts or other hard substances. The
teeth are brittle, and are often broken in this way. The use of candy
and too much sweet food is also likely to injure the teeth.

~13.~ Some people think that it is not necessary to take care of the
first set of teeth. This is a great mistake. If the first set are lost
or are unhealthy, the second set will not be as perfect as they should
be. It is plain that we should not neglect our teeth at any time of
life.

~14. Tobacco.~--When a person first uses tobacco, it is apt to make him
very sick at the stomach. After he has used tobacco a few times it does
not make him sick, but it continues to do his stomach and other organs
harm, and after a time may injure him very seriously. Smokers sometimes
suffer from a horrible disease of the mouth or throat known as cancer.

~15. Effects of Alcohol upon the Stomach.~--If you should put a little
alcohol into your eye, the eye would become very red. When men take
strong liquors into their stomachs, the delicate membrane lining the
stomach becomes red in the same way. Perhaps you will ask how do we know
that alcohol has such an effect upon the stomach. More than sixty years
ago there lived in Michigan a man named Alexis St. Martin. One day he
was, by accident, shot in such a way that a large opening was made right
through the skin and flesh and into the stomach. The good doctor who
attended him took such excellent care of him that he got well. But when
he recovered, the hole in his stomach remained, so that the doctor could
look in and see just what was going on. St. Martin sometimes drank
whiskey, and when he did, the doctor often looked into his stomach to
see what the effect was, and he noticed that the inside of the stomach