NATURE OF FERMENTED DRINKS 



8l 



When we see meat or vegetables spoiling, bread or 

 cheese molding, fruit rotting, or milk turning sour, we 

 simply see a few of the countless examples of nature's 

 great law of decay. This " working " or souring only 

 represents the first step of the return to the atmosphere 

 and to the soil of all that has lived. 



120. Fermentation. The " working," or fermenting, as 

 it is called, of sweet fruit, plant, or other vegetable juices, 

 which takes place very soon after they are pressed out, is 

 another and familiar ex- 

 ample of the same wise 

 provision of nature. This 

 last process is not accom- 

 panied by foul -smelling 

 odors, as are most of the 

 others, but by a peculiar 

 bubbling of the liquid 

 caused by the escaping 

 gases ; hence the name 



FIG. 55. Showing the Comparative 

 Size of Molds (a), Yeast (b and <:), 

 and Bacteria (d}. 



" fermentation," which is taken from a Latin word meaning 

 to boil. 



Fermentation in its widest sense includes the changes 

 going on in the putrefying meat, the molding cheese, and 

 the rotting fruit, as well as in the fermenting fruit juice. 

 They are all forms of decomposition that set free the sim- 

 pler substances composing animal and vegetable matter. 

 For all these one law holds good. It is this : 



Fermentation entirely changes the nature of the substance fer- 

 mented. 



121. The Importance of Bacteria in Nature's Work of 

 Decay. What causes all these various processes of de- 

 composition ? Are plants and animals so constructed that 



