226 Agricultural Bacteriology. 



the action of organisms, such as the molds, the same as 

 are concerned in the heating of manures. Ear corn, 

 placed in the crib before it is well dried may likewise 

 mold, although the moisture content is too low to allow 

 growth of bacteria. Various ground-feeds, as meal, 

 readily mold if kept in a damp place. Wheat becomes 

 musty when damp. All of these troubles are caused by 

 the presence of sufficient moisture to allow of mold 

 growth. 



The preservation of many foods is also made possible 

 by drying, as apples and other fruits, berries, green corn, 

 etc. Meat is also protected from putrefaction in this 

 way. As previously stated, the muscles of a healthy ani- 

 mal are free from bacteria; but in cutting up the carcass 

 the meat becomes contaminated with bacteria and conse- 

 quently undergoes decomposition. If, however, the 

 meat is placed in a dry atmosphere, the outer surface 

 soon becomes so dry as to prevent the growth of bacteria, 

 and as the moist inner part remains free from organisms 

 It does not decompose. If the drying is continued until 

 the entire piece is firm, it will keep for an indefinite 

 period. In South America dried meat is extensively pre- 

 pared and is shipped to all parts of the world. When 

 ground and mixed^ with fat it is a very concentrated 

 form of food and is used where fresh meat can not be 

 procured. 



Dried milk, or milk powder, and dried eggs are articles 

 of commerce and are extensively used in place of the 

 fresh materials, especially by bakers. 



The drying of foods usually injures their flavor ma- 

 terially, consequently preservation by desiccation is be- 

 ing replaced, wherever possible, by other methods that 

 conserve the natural flavor to a greater degree. 



