A boy once said that if he saw a consumptive spit on the sidewalk, he would want to hit him, and to emphasize his remarks he spat on the floor of the room, just as you have seen boys spit on the ground when they were thinking of fighting. There might have been some germs of consumption in the sputum this boy left on the floor. Of course he was very positive that he did not have consumption, but this was no proof that his sputum was free from the germs of this disease. Remember that it is not only the sick who should never spit on the floor or sidewalk, but that no person should ever spit on any floor or sidewalk, or into any place except into a cuspidor, handkerchief, or spit-cup of some kind. If you spit into a handkerchief, a paper napkin, or a bit of cloth, be sure to burn it as soon as you can, before it becomes dry. =Questions.= 1. In what places do we find germs most abundant in the air? 2. How do well-bred people avoid putting disease germs into the air? 3. Why is it important for well people to take the same precautions as sick people? =Remember.= 1. Every person should hold a handkerchief before the face when coughing or sneezing. 2. Never spit except into a cuspidor, handkerchief, spit-cup, or other special receptacle. 3. If well people will practice clean habits, the sick will be helped and encouraged to follow their example. 4. Remember: No spit, no consumption. CHAPTER XXI INSECTS AS CARRIERS OF DISEASE [Sidenote: Some insects that carry disease] Certain diseases are given to human beings by the bites of insects. We know that certain ticks and mosquitoes carry certain germs. It is also probable that disease germs are transferred from diseased to well persons by bedbugs and other insects that bite. [Sidenote: How yellow fever is transmitted] For a long time it was thought that yellow fever was carried through the air, but now it has been proved that yellow fever is not carried in this way. A well person can sleep with one who has yellow fever and not catch the disease. Yellow fever infection is carried from a yellow fever patient to a healthy person only by a certain mosquito. Keep this mosquito away from the yellow fever patients and there can be no spread of the disease. [Illustration: FIG. 48. The mosquito that carries yellow fever.] It is not many years since yellow fever was one of the most dreaded diseases in warm countries. To-day there is not the same fear of it, for the source of the disease has been discovered and practical methods have been devised to get rid of the mosquito which carries it. [Sidenote: How malaria is transmitted]