THE STORY OF THE BACTERIA. 43 



citizen working- away as diligently as he can 

 to make the world more comfortable for his 

 betters. 



It has long been known by the makers of 

 beverages that alcohol is formed in certain 

 sugary mixtures by a process called fermenta- 

 tion, and that this tearing to pieces of the 

 sugar into other compounds, one of which is 

 alcohol, is accomplished by a little living or- 

 ganism called yeast, closely related to the 

 bacteria. In the earlier days of beer- and wine- 

 making it was often found that the beer did 

 not work or ferment properly, and that wine 

 would get sour or bitter. We now know that 

 these irregularities are due to the fact that 

 certain kinds of bacteria are apt to get into 

 the wine or beer during the manufacture, and 

 when they do a bitter struggle for food goes 

 on between the yeasts and the bacteria ; or 

 the latter may bide their time, and later in the 

 process begin to grow and produce very unde- 

 sirable compounds in the fluids. So the man- 

 ufacturer has to be on the alert, and at the 

 right moment come to the rescue of his army 

 of servitors, the yeast plants, and introduce 





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