HOUSEHOLD BACTERIOLOGY 



PART II. 



WORK OF BACTERIA 



When bacterial life first appeared upon the earth 

 may never be known, but that it existed thousands of 

 years before man made its acquaintance is surely true. 

 Indeed, it was within the last quarter of the nine- 

 teenth century that the knowledge of bacteria became 

 of value or was reduced to a science. The problems of 

 bacteriology are now being solved very rapidly. What 

 future generations may add, who can tell ? 



Although bacteriology is the youngest of all the 

 sciences, it occupies a very important place among 

 them because of its intimate connection with disease, 

 with sanitation or the prevention of disease ; with 

 successful agriculture, and with the manufacture of 

 many products. 



In the eyes of the law every person is considered tr B efni 

 innocent until proved guilty. It may be well for us Bacten * 

 to look at the beneficent role which bacteria play in 

 the world, that we may the more justly consider 

 their harmful work. We can hardly believe that the 

 most numerous forms of life were intended to work 

 only harm to man. 



