XVIII 



RECOVERY FROM BACTERIAL INFECTIONS 



In the combat waged against disease, the body is 

 equipped with natural defences that are called into 

 play by the entrance of bacteria. In addition, each 

 particular form of infection excites the production of 

 antibodies that are specific for the disease in question. 

 By means of these non-specific and specific defences, 

 spontaneous or natural recovery is brought about. 



In the case of the bacteria that produce their dele- 

 terious effects by means of separated soluble toxins, 

 for example the diphtheria and tetanus bacilli, the 

 body defences take the form of specific antitoxic sub- 

 stances, which, by neutralizing the toxins, cause a 

 secondary destruction of the infecting organisms. 

 Where the invading bacteria act by means of endo- 

 toxins that are inseparably bound up within their 

 protoplasm, the body acts directly against the micro- 

 organisms themselves through various soluble bac- 

 tericidal substances in the blood-fluid. After the bac- 

 teria have been killed, their bodies are taken up by 

 the leucocytes (phagocytosis), and their endotoxins 

 neutralized by non-specific oxidizing substances in the 

 leucocytes. 



Experimental and clinical evidence leads to the 

 belief that there are in the blood two types of bac- 



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