144 BACTERIA, YEASTS, AND MOLDS 



still further protected from- decay by the addition of a 

 small quantity of salt. Such preserved meats are then 

 shipped all over the world and form an excellent food 

 which can be kept indefinitely. The commercial names 

 under which this dried meat is sold are several ; the more 

 common ones are charque and tassajo. Such meats, though 

 useful, do not take the place of the fresh product. Their 

 flavor is changed ; they are tough and not easy to digest. 

 A more familiar method of preserving meat is the cur- 

 ing of hams, bacon, etc. In such cases the flesh is first 

 salted thoroughly by soaking in a brine, and then sub- 

 jected to the action of smoke from burning wood. Such 

 smoked food is thoroughly protected from bacterial action 

 by at least three factors : (i) The material becomes some- 

 what dry, so that the bacteria cannot readily act upon it. 



(2) The action of the smoke is in a measure antiseptic, 

 partly destroying bacterial life upon the surface, and at the 

 same time so impregnating the meat with injurious vola- 

 tile products that bacteria cannot ordinarily grow in it. 



(3) The salt is itself injurious to bacterial life. The ham is 

 thus preserved from the action of bacteria by a combina- 

 tion of drying, smoking, and salting, all of which processes 

 together are sufficient to prevent completely the subse- 

 quent growth of bacteria, although molds may grow upon 

 it if it is not properly protected. The same thing is true of 

 dried beef, a material preserved from decay partly by a pre- 

 liminary soaking in brine and partly by a subsequent drying. 

 The methods of preparing dried beef vary. Sometimes the 

 process is one of artificial drying simply, but commonly 

 smoking and salting are adopted to aid in the process. The 

 drying of flesh is sometimes carried out so completely that 



