The Preservation of Health 



291 



As stated before, bacteria may enter the body with the 

 food and water. We have already shown how the air may 

 become infected with the germs of disease from the dust 

 of dried sputa (page 177). 



Finally, bacteria may gain access to the body by 

 inoculation, or by inserting the virus through a broken 

 surface of the skin. This may result from using soiled 

 instruments, from gunshot injuries, broken glass, rusty 

 nails, and from many other causes. 



453. How the Body defends itself against Bacteria. 

 Germs of disease constantly assail the bodily tissues. 

 There is a continual 

 warfare between bac- 

 teria and the living 

 cells. The plasma of 

 the blood acts in some 

 unknown manner to 

 help kill the disease- 

 producing germs. 



The white blood 

 corpuscles wage an 

 unceasing warfare 

 against bacteria and 

 the toxins. While 

 this warfare is going 

 on and disease shows 

 itself, a poison of 



FIG. 1 59. Bacilli of Diphtheria. 

 (Magnified 1000 diameters.) 



another type, called for convenience antitoxin, is formed in 

 the serum of the blood, which may antagonize the toxins 

 and destroy their poisonous action. 



454. Antitoxin Treatment of Disease. Within the past 

 few years remarkable progress has been made by tireless 

 scientific workers in their efforts to modify the action of 



