ld always carry a handkerchief and use it so as to blow the
germs out of your nose. You should have a clean handkerchief every day.

[Illustration: =Photograph of model of the nose and throat.=

_A._ tonsil; _B._ adenoids; _C._ opening of Eustachian tube.]

=220. Adenoids and large tonsils.=--Sometimes children have large
tonsils growing in the back of the throat, or soft bunches of flesh
called _adenoids_ back of the nose. These children cannot breathe well
through the nose, but must breathe through the mouth. Then they take
dust and disease germs deep into the body, and so take colds and other
sickness easily. If a child has adenoids or large tonsils, an
operation should be done to take them out.

=221. Cleanliness of the mouth.=--We often breathe dust and disease
germs into the mouth or snuff them into the throat from the nose. Then
they are caught between the teeth and in the folds of the cheeks and
throat. There they may grow, and finally go deeper into the body and
make us sick. A dirty mouth is very often the cause of colds and other
sickness.

We should keep our mouths clean by brushing our teeth with a
toothbrush two or three times a day. We should also rub the toothbrush
over the tongue and around the back part of the throat so as to clean
the germs from every part of the mouth. Each child should have a
toothbrush of his own, and should use it every day.

=222. Contagious diseases.=--Diphtheria, whooping cough, measles,
scarlet fever, and smallpox are all dangerous kinds of sickness, and
spread with great ease. The germs may float in the air, and we may
take them into our bodies if we go into a room where any one has the
sickness. So we call these diseases _contagious_. If a person has one
of these diseases, he should be made to stay in a house or room by
himself until he is well. Keeping the sick away from well persons is
called _quarantine_. When the sickness is cured, the sick room and
everything in it should be cleaned and washed so as to kill the germs.

=223. Board of health.=--There is a board of health in every city and
town. The men on the board show persons how to keep diseases from
spreading, and make them obey the rules of health. Everybody in a town
should help the board of health in every possible way.

WHAT WE HAVE LEARNED

1. The white blood cells of our body kill disease germs.

2. We catch cold by taking disease germs into our body.

3. The germs of colds are not