PART I. 



GENERAL NATURE OF BACTERIA AM) 

 FERMENTATIONS. 



CHAPTER I. 



THE NATURE OF BACTERIA. 



IMPORTANCE OF BACTERIOLOGY TO AGRICULTURE. 



IT is about two centuries since the microscopic organisms 

 now known as bacteria were first seen. The Dutch micros- 

 copist, Leeuwenhoek, was the first to study them, in 1695, 

 and his descriptions, considering the fact that he had only 

 simple lenses to work with, were remarkably correct. Even 

 his suggestions concerning their nature sound quite modern 

 and were certainly superior to much of the speculation that 

 followed. For 1 50 years after Leeuwenhoek, although the 

 microscope became a familiar plaything, it was hardly thought 

 that these minute organisms offered a subject for serious study. 

 For a century, they were simply objects of speculation, and 

 many were the exclamations which they excited as to the 

 wonders of nature, with here and there a suggestion as to 

 their possible importance in producing certain natural phe- 

 nomena. 



Not until toward the middle of the igth century was it con- 

 ceived that the microscopic organisms, grouped together under 

 the general head of animalcule?, could have more than scientific 

 import. At that time there began to appear suggestions as to 

 2 (17) 



