CHAPTER IX. 

 THE ACUTE SELF-LIMITED INFECTIONS. 



IN this chapter are included the infectious diseases 

 which are due to a specific microorganism and which 

 tend to run a definite course. 



BACTERIUM DIPHTHERIA. 



Diphtheria is a disease caused by the Bacterium 

 diphtheric?, or diphtheria bacillus, or Klebs-Loffler 

 bacillus, characterized by the development of a so- 

 called false membrane upon a mucous membrane or 

 abraded surface, from which the soluble poisons are 

 absorbed by the circulation. This false membrane is 

 an inflammatory exudate thrown out by the body under 

 the stimulus of the bacteria, as a means of protection 

 against them. Myriads of bacteria are included in 

 the meshes of this exudate. If the false membrane 

 be removed a raw, bleeding surface is exposed. Some- 

 times this is done for the purpose of applying remedial 

 agents. The false membrane of diphtheria appears 

 most commonly upon the throat and nose, but it may 

 be found upon the eye, vagina, or skin wound. 



This is the disease par excellence for explaining the 

 effect of toxins extracellular and separable from the 

 bacteria. The organisms do not enter the body, but 



