164 BACTERIA, YEASTS, AND MOLDS 



candied material which can be used only as a sweetmeat 

 or a sauce. This method of preservation is used to-day 

 much less than in earlier years before the wide extension 

 of the process of canning. 



Salt. A more common, harmless preservative is salt. 

 Materials thoroughly salted are completely protected from 

 bacterial growth. Since salt is harmless and, indeed, a 

 necessary ingredient in our food, such a method of pre- 

 serving is quite legitimate. Salt is used as a preservative 

 for a variety of food products. Fat pork is very easily pre- 

 served by keeping it immersed in a strong salt solution 

 called brine, producing what is known as salt pork. Corned 

 beef and corned bacon are also preserved in the same way. 

 Cheeses are sometimes preserved in brine, and the same is 

 true of eggs. In other cases the salt is mixed with the food. 

 Hams and some other meats are preserved partly by salt- 

 ing, and in most forms of dried beef salt is added to assist 

 in the preserving. It is used for the preservation of great 

 quantities of fish, particularly marine fish, which may in 

 this way be preserved indefinitely from bacterial action. 

 Fresh-water fish could be preserved equally well, but since 

 they are not generally caught in large numbers they are 

 rarely salted. The salting of butter is a procedure adopted 

 partly for the purpose of giving a salty flavor and partly 

 for the purpose of its preservation. In the preparation of 

 cheeses salt is almost always used, for after their manufac- 

 ture they are usually kept for weeks or months before they 

 are ready for market, and salt is rubbed into their surfaces 

 to prevent the growth of undesirable microorganisms. 



It must be remembered that, while salting preserves the 

 material from decay, it does not preserve its fresh form. 



