440 



FOODS 



Preserving Food. When it is desired to preserve food 

 for a long time, especial care must be taken. It has been 

 found that thoroughly drying food will protect it against 

 bacteria ; that freezing or smoking fish and meat preserves 

 them ; that salt and vinegar and spices act as preservatives ; 

 that if fruits and vegetables are heated for some time at a 

 boiling temperature and tightly sealed in cans they will 



keep ; that fruits do 

 not spoil if placed in 

 strong sugar sirups; 

 that fruits and vege- 

 tables and eggs can be 

 kept without spoiling 

 where the tempera- 

 ture is maintained 

 at a little above the 

 freezing point. 



In all these cases 

 the bacteria in the 

 food are either en- 

 tirely destroyed and 

 the food is absolutely 

 protected from other 



bacteria, or else the growth of the bacteria is completely 

 checked. Sometimes eggs are preserved for a considerable 

 time by placing them in a waterglass solution. In this 

 case the waterglass fills up the tiny pores in the shell of the 

 egg and keeps out the bacteria just as paint keeps them 

 out of wood. In the case of the egg, however, there is plenty 

 of moisture within the egg for the growth of whatever bac- 

 teria may be present, whereas in painted dry wood the 

 moisture is kept out and the bacteria are unable to grow. 



PREPARING SMOKED FISH AT GLOUCESTER 



