PRESERVATION BY DRYING 143 



material is left so completely dry that bacteria cannot 

 consume it at all. Dried crackers, if kept dry, can be pre- 

 served indefinitely, neither decaying nor molding. In the 

 case of bread and soft cakes the water is not wholly driven 

 off; hence these foods are not protected entirely from 

 the action of microorganisms. As a rule bacteria cannot 

 attack them and the housewife hardly fears their decay; 

 but molds can grow upon them readily, and they must 

 therefore be protected by means already suggested. 



In addition to foods that are naturally dry, a large 

 variety of others may be preserved completely from bac- 

 terial action by artificial drying. This method of pre- 

 serving has been known for centuries and is understood 

 by both civilized people and savages. Most kinds of meat 

 can be treated in this way, and the drying of meat is 

 carried on to a large extent in different parts of the world. 

 The frontiersman and the hunter in the woods sometimes 

 cut the Hesh of deer, bears, and other animals into thin 

 strips and hang it where it will be dried by the heat of the 

 sun. This dried meat is called pemmican, a. tough, hard, 

 dry substance which can be kept for months without 

 danger of decay. It is good food, though somewhat less 

 digestible than fresh meat. A similar drying could be 

 adopted in the household to preserve meats, but it is 

 rarely worth while. 



Usually the efficacy of the drying is increased by the 

 use of salt. This plan for the preservation of meat is 

 adopted in many parts of the world where cattle are plenty 

 and the market is distant. In South America thousands of 

 tons of dried flesh are prepared each year, the drying in 

 this case being produced artificially, and the meat being 



