The germs of sickness are so small that a million can hang to the hands or clothing and not be seen. For this reason they are often left clinging to the fingers, desks, books, and pencils, and travel in large numbers on the feet of flies. The surest way the germs have of getting from one person to another is by the common drinking cup. [Illustration: FIG. 95.--Photograph of clear beef broth jelly in which a fly walked five minutes scattering germs. Two days later each germ brushed off the fly's feet grew into a city of germs appearing as a white spot.] =The Common Drinking Cup is an Exchange Station for Germs.=--The most careful examinations have shown that there are thousands of children as well as grown persons who have very light attacks of scarlet fever, tuberculosis, or other diseases and go to school or about their work scattering the germs of sickness in their spit. A child seldom drinks from a cup without leaving on it thousands of germs. Some of these may be germs which will cause sickness. On one drinking cup used in a school, the germs were found to be as thick as the leaves on a maple tree in June. In an Ohio school one warm day, a boy with beginning measles drank from the cup which was afterward used on the same day by the teacher and all the other pupils. In less than two weeks every pupil and the teacher were suffering from measles. _Put nothing into your mouth which has been in another's mouth._ [Illustration: FIG. 96.--A schoolhouse in Morgan county, Ohio, where sixteen pupils and the teacher caught the measles in one day by drinking from a cup which had been used by a boy sick with the measles.] =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. [Illustration: 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.]