=175. How the throat affects the ear.=--An air tube runs from the
inside of the ear to the mouth. Sometimes when you blow your nose, you
blow air into the ear. This makes you partly deaf and you hear a
roaring in your ears.

Sometimes when you have a cold in your throat, this little tube is
stopped. Then your ear may ache and may even discharge matter. This
may make you somewhat deaf. Earache and deafness are most often due to
a cold in the throat and a stoppage of this tube.

Many little boys and girls are deaf and do not know it. They cannot
hear the teacher well, and sometimes the teacher thinks they are bad
or careless because they do not answer.

=176. Care of the ears.=--Very loud noises may harm the ear and make
you deaf. When you expect a very loud noise, put your fingers in your
ears to shut out the sound.

Boxing the ears may break their tiny drums and make you deaf.

Do not get cold water in your ear. This may cause an earache and make
you deaf. If you get water in your ear while you are in swimming, turn
your head to one side and shake it. This will get the water out.

Do not put cotton or anything else into your ears.

=177. Smell.=--We smell with the nose. Some things give out a vapor to
the air. When we draw the air into the nose, this vapor touches the
nerves, and we perceive a smell. The nerves are high up in the nose.
In order to perceive smell clearly, we sniff the air far up the nose.

=178. Use of smell.=--Bad air and spoiled food smell bad. A bad smell
is the sign of something spoiled. The sense of smell tells us when
food or air is unfit for use. Some people try to hide a bad smell with
perfumery. To do this only makes the danger greater, for then the
smell does not tell us of the danger of food or air.

Some animals can smell much better than a man. A dog will smell the
track of a wild animal hours after it is made. Savages can smell much
better than civilized men.

=179. Taste.=--We taste with the tongue. Dry food has no taste, but it
must first dissolve in the mouth. Spoiled food tastes bad. Bad-tasting
food is not fit to eat. Taste tells us whether food is good or bad.

We can learn to like the taste of harmful things. At first no one
likes tobacco or strong drink, but the liking is formed the more one
uses these. We ought to be careful not to begin to use such things.

_Alcohol_ and _tobacco_ burn the mouth and harm the taste. Food does
not taste so good and we may eat spoiled f