PART VII 



BACTERIA IN RELATION TO PRESERVATION 

 OF FOOD 



CHAPTER XLII 

 BACTERIA IN RELATION TO CANNING 



THE perishable products of the farm have but a 

 brief existence. The succulent fruits and vegetables decay 

 and vanish; milk turns sour; butter becomes rancid; 

 wine, juices and cider are changed into acid liquids; and 

 meat and eggs undergo putrefaction. Decay and putre- 

 faction, as natural phenomena, were forced upon the 

 attention of man as he emerged from savagery. When 

 he realized that food-preservation and his own well- 

 being were so intimately related, he endeavored to de- 

 vise means for arresting the course of dissolution. The 

 passing centuries taught him that moisture and warmth 

 furnish suitable conditions for the rapid decay of vege- 

 table and animal materials. They taught him that, 

 for a short time at least, boiling will arrest the decom- 

 position of food. They taught him that the addition 

 of substances like salt or saltpeter, or the natural pro- 

 cesses of souring, may be utilized in the preservation 

 of food products. 



(431) 



