[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 often found in the air out of doors. They are often found in the foul air of houses. 4. If a person has a cold, he should keep away from other persons, so as to keep from spreading the sickness. 5. Cleansing the nose helps us to keep from catching cold. 6. Cleansing the teeth and the inside of the mouth removes many disease germs. 7. Adenoids and large tonsils should be taken from the throat by an operation. 8. If a person has a dangerous contagious disease, he should be quarantined. 9. Boards of health have charge of the prevention of contagious diseases. INDEX