HOW BACTERIA GET INTO THE BODY 197 



How bacteria get into the body. Disease bacteria do not 

 harm us so long as they remain outside the body, but as soon as 

 they get into the body through the nose, mouth, wounds, or 

 cuts they may develop and produce disease. Every cut or 

 wound is an open door to bacteria, and the mouth and nose are 

 permanent channels by which they enter. If milk from dis- 

 eased cows or water from polluted rivers is drunk, multi- 

 tudes of disease bacteria get into the body. If good food 

 is handled with soiled hands, bacteria pass into the body with 



FIG. 69. Street sprinkler and sweeper. 



the food. A drinking cup that is used by many people always 

 has disease germs on it. 



Bacteria are blown through the air, but finally settle with 

 dust and dirt on exposed surfaces and remain there until dis- 

 turbed by wind, sweeping, or dusting. The person who sweeps 



i with a damp broom, and dusts with a damp cloth keeps down 

 the dust and protects herself against bacteria. The city which 

 sprinkles or flushes its streets with water before the street 



I cleaners begin their sweeping, protects its citizens against un- 

 necessary infection from bacteria (Fig. 69). 



