Sources of Bacterial Infection 177 



dramatic and frightful as they are, which 

 carry off prematurely the largest number of 

 people; but it is the bacterial diseases which 

 we have constantly with us, and to which 

 we have become so accustomed that we do 

 not usually realize their vast importance, and 

 against which systematic and persistent cru- 

 sades on the part of the health authorities are 

 only occasionally and fitfully undertaken. 



Civilized communities have ceased to fear 

 Asiatic cholera very much, because we have 

 learned that it is easily suppressed by proper 

 sanitation. The traditional ravages of the 

 plague are possible only among the filthy in 

 person and surroundings. Small-pox we do 

 not now seriously dread, because immunity 

 can be secured by a scratch upon the skin. 

 Diphtheria and cerebro-spinal meningitis have 

 largely lost their terrors since the discovery of 

 the life-saving antitoxins. Hydrophobia is 

 fully within our control. 



But how is it with some of the less dramatic 

 germ diseases which we have always with us, 

 although we have known for many years how 

 they can be largely prevented? 



