214 ELEMENTAEY AGRICULTURE 



warm, moist surface, such as foods, they readily 

 germinate and spread over the surface. Molds may 

 be destroyed by heating to a high temperature for 

 about twenty minutes. Canned and preserved fruits 

 are more liable to be injured by yeast and mold 

 than by bacteria. 



Canning Fruit. The important things to remem- 

 ber in canning and preserving are to keep all cook- 

 ing utensils clean and to kill all germs. This we 

 call sterilizing. The kettles, jars, strainers, covers, 

 rubbers, and other utensils used in canning, must 

 be scalded to kill the germs, or bacteria. When 

 all germs in the jars and fruit are killed, the cans 

 are sealed while hot so as not to permit other germs 

 from the air to enter. If live germs are left in 

 canned fruit, a gas will escape which means that 

 decay or decomposition has set in, and the food has 

 begun to spoil. Foods and other organic matter 

 will not decay if germs are kept out. 



Bacteria. Bacteria multiply rapidly in meat, 

 milk, and legumes. They cannot grow without the 

 presence of water. Dried fruits and meats will keep 

 because there is no water in which the germs may 

 grow. Neither can bacteria live in a strong solution 

 of common salt. That is why we salt meat to pre- 

 serve it. 



Smoking Meats. Meats are also preserved from 

 germs by smoking. Smoking leaves a thin coat of 

 creosote on the surface of the meat, which not only 

 kills all germs but gives the meat a good flavor. 



