22 BACTERIA 



years. Ancient methods of preserving foods from putrefying, and 

 which are still in vogue, depend upon the employment of some of 

 these agents, which are prejudicial to bacterial life. Meats are 

 salted, pickled, dried, or smoked. Fruits are dried, pickled, or 

 immersed in strong saccharine solution, in order to preserve them 

 from decay, in every instance, the absence of moisture, the excess 

 of salt, sugar, or vinegar, or the pyroligneous acid from the smok- 

 ing, prevents bacterial growth, and consequently, decay of the 

 foodstuff. The products of bacterial growths often inhibit, or 

 destroy, the cells that made them, as well as other bacteria. 

 B. pyocyaneus and S. cholera, have this property of secreting 

 autolytic ferments. 



