DANGER IN FOOD 431 



Like the fly, the malaria mosquito is a "home product." It lives 

 very near the place where it was hatched. To get rid of it, we must 

 destroy its breeding places. Open cisterns, wells, rain barrels, water- 

 ing troughs, ditches, puddles, sagging eaves troughs, broken crockery, 

 and tin cans, anything that can hold water, all these give the mosquito 

 its opportunity. All unnecessary holders of water should be removed 

 or buried; the others should be carefully screened. Ditches should be 

 drained. Puddles, cisterns, and barrels that contain "wigglers" 

 should be treated with a little kerosene (cf. 339), and then screened. 

 Cities often suffer needlessly from mosquitoes, because the creatures 

 are allowed to develop in street catch basins. The catch basin receives 

 the water that comes from the street, and the water that remains in it 

 acts as a ''water seal" to the street sewer, just as the "trap" does to 

 the house sewer (cf. 236). If there is no rain for some time, and if the 

 catch basin is not "flushed out," the standing water permits the mos- 

 quito to breed. A little kerosene thrown into the catch basins would 

 rid the neighborhood of the nuisance. 



425. Danger in Food. If the body were unprotected, 

 a single germ might cause a disease. But this is rarely 

 possible. A few germs are usually destroyed at once by 

 the blood. But a large number (many millions) may be 

 introduced into the body in a single bite of bad food, or 

 in a mouthful of infected water. So we need to be very 

 careful about the food we eat. Only persons with clean 

 hands and clean clothing should prepare and handle 

 food, and food should be stored only in clean, protected 

 places (Fig. 304). If customers were clean themselves, 

 and were particular about the cleanliness of what they 

 buy and use, their groceries, meat markets, bakeries, 

 fruit stores, candy kitchens, laundries, milk depots, etc., 

 would be clean too. 



We must be particular, also, about tainted, or decayed, food. Over- 

 ripe fruit is always to be suspected. Many a household is so anxious 



