174 THE STORY OF GERM LIFE. 



and surgical gangrene need not be taken into con- 

 sideration at all. Indeed, the modern surgeon 

 hardly knows what surgical gangrene is, and bac- 

 teriologists have had practically no chance to 

 study it. Secondary infections have largely dis- 

 appeared, and the surgeon is concerned simply 

 with the effect of the wound itself, and the power 

 of the body to withstand the shock and subse- 

 quently heal the wound. 



With these secondary troubles no longer to 

 disturb him, the surgeon has become more and 

 more bold. Operations formerly not dreamed of 

 are now performed without hesitation. In former 

 years an operation which opened the abdominal 

 cavity was not thought possible, or at least it was 

 so nearly certain to result fatally that it was re- 

 sorted to only on the last extremity; while to-day 

 such operations are hardly regarded as serious. 

 Even brain surgery is becoming more and more 

 common. Possibly our surgeons are passing too 

 far to the other extreme, and, feeling their power of 

 performing so many operations without inconven- 

 ience or danger, they are using the knife in cases 

 where it would be better to leave Nature to her- 

 self for her own healing. But, be this as it may, 

 it is impossible to estimate the amount of suffer- 

 ing prevented and the number of lives saved by 

 the mastery of the secondary inflammatory trou- 

 bles which used to follow surgical wounds. 



Preventive medicine, then, has for its object 

 the prevention rather than the cure of disease. 

 By showing the causes of disease and telling us 

 where and how they are contracted, it is telling 

 us how they may to a large extent be avoided. 

 Unlike practical medicine, this subject is one 

 which has a direct relation to the general public. 



