The Golden Rule.—If you have a catching sickness, such as measles, chicken pox, or whooping cough, stay away from others. Since the germs of some diseases, like scarlet fever and diphtheria, remain in the spit sometimes several months after you feel well, don't scatter your spit. Hold a handkerchief before your face when you sneeze or cough. Wash your hands before handling food.
Some Animals carry Sickness.—Mosquitoes carry malaria and yellow fever and some other diseases. Flies carry typhoid fever, grippe, diphtheria, and tuberculosis. Bedbugs and fleas carry the plague and leprosy. Rats carry the plague. Cats sometimes carry diphtheria. Many cows have tuberculosis and the germs of this disease are then sometimes found in their milk. Some children have caught tuberculosis from drinking such milk.
Fig. 97 —A pane of glass held about two feet before the face of a boy who sneezed. The spots are the droplets of spit thrown out. Each spot showed under the microscope from 50 to 1000 germs.
Keeping away Smallpox.—Smallpox was once the most terrible of all diseases. It is so catching that two or three were often sick with it at one time in the same family. Sometimes nearly one half the people of a whole town would have the disease in one year. Over a hundred years ago nearly every grown up person had little pits scattered over his face as a result of having had smallpox.
You can always keep away smallpox by being vaccinated. The doctor can vaccinate you by putting on the freshly scraped skin of your arm some weak smallpox germs from a clean healthy calf which has been vaccinated. Your arm will in a few days get sore and you will not feel well for about one week, but you will be made safe from smallpox for several years.
Fifty nurses were vaccinated in Philadelphia and cared for many sick with the smallpox, staying with them day after day, but not one of the nurses took the disease. Every one should be vaccinated when a year old and again at the age of ten or twelve years.
Colds.—Some colds are catching, but we generally take cold because we have weak bodies or have been careless. If you want to be free from colds, remember these six rules:—
Don't sit still in wet clothes or with wet feet.