32 GOOD HEALTH 



Cooks also know that microbes work fastest in warm 

 places and slowest where it is cold, and for this reason, 

 when they want milk to sour in a hurry, they put it in 

 a warm place; when they want it to keep sweet, they 

 put it in the ice chest. They know that it will surely 

 keep if it is frozen. They also know that meat, if it is 

 frozen solid, will keep long enough to be carried to the 

 North Pole and back again, though on a warm summer 

 day, in a hot kitchen, it may begin to spoil in a single 

 afternoon. 



To understand this we must know that microbes do 

 not die when they are frozen. Instead, they can endure 

 more cold than the strongest man. It is true, of course, 

 that while they are frozen they can do no more work 

 than a frozen man, but the difference is that when the 

 freezing is over the man is dead, while the little microbe 

 is as sprightly as ever and ready for business. 



Since they are so plucky about cold, it seems as if 

 they ought to endure great heat too. Yet this they can- 

 not do, for fire, or water that is boiling hot, actually kills 

 them. This then is our good fortune, for we manage to 

 save some of our food by boiling the microbes that get 

 into it. 



There are two sides to the secret of keeping things 

 from spoiling: 



1. Kill the microbes. 



2. Put the food where no microbes can get to it. 



