254 PARASITIC BACTERIA. 



the body and is dependent upon their normal functions. It is only 

 the living cell which can resist the invasion of microorganisms, 

 either wholly or partially. From this it follows that the resistance 

 will be greatest when the body cells are in the highest state of 

 physical activity, and will diminish when they become somewhat 

 impaired in vitality. Anything which tends to reduce the physical 

 health of the individual tends to reduce his power of resistance. 

 For example: sometimes an individual shows a great tendency 

 to develop boils or abscesses, and but little power of resisting them. 

 We say his "blood is in a bad condition." By this is really meant 

 that his body activities are so repressed that he is unable to resist 

 the invasion of some of the common bacteria which are present on 

 every hand and which an individual in healthy condition easily 

 repels. If his physical vigor can be restored, the troubles will 

 disappear, although the bacteria which produce the boils and 

 abscesses are just as abundant around him as before. Physical 

 vigor is the best protection against the invasion of parasitic bacteria, 

 and a weakened physical condition invites attack. 



This matter is emphasized here because it is too generally lost 

 sight of in the combat against infectious diseases. During the first 

 years of the study of bacteriology there was a very general tendency, 

 in the attempt to avoid diseases, to place the whole emphasis 

 upon the methods of avoiding bacteria. If a disease is caused by a 

 bacterium, what more natural method could be suggested for 

 avoiding it than to avoid the bacterium? In accordance with this 

 idea there developed a long series of rules and regulations suggested 

 by bacteriologists and adopted by health boards, all designed for 

 the prevention of the distribution of disease germs. This is, 

 indeed, the foundation of modern sanitation. 



Increasing of Individual Resistance. Recently there has 

 been a manifest reaction against this one-sided attitude. While 

 the importance of preventing the distribution of bacteria is still 

 acknowledged, there is to-day a growing recognition of another 

 side to the ques.tion. The strengthening of personal vigor is of no 

 less importance many believe it is of more importance than 

 the preventing of the distribution of bacteria. The weakening of 



