NEW CONCEPTIONS IN SCIENCE 



it, the crisis was soon past, and within an hour he 

 was back at work. " Epatant" murmured France ; 

 and so it was. 



Pasteur had unveiled the cause of disease; he 

 and his disciples had found new means of com- 

 bating it. It remained to inquire what was the 

 mechanism by which the cure works. We may take 

 a concrete instance. The microbe of diphtheria 

 Professor Behring believes to be ubiquitous that 

 is to say, always more or less present. Under 

 favorable circumstances, as, for example, a weak- 

 ened condition of the body, it finds lodgment in 

 the throat, begins to multiply with extraordinary 

 rapidity, and covers its fungus-like growth with the 

 well - known white membrane. As a part of its 

 vital activity, it secretes a powerful poison, as, let 

 us say, the cells of a cow's udder secrete milk, or 

 the poison glands of a rattlesnake produce venom. 

 This poison, seeping through the membrane, per- 

 meates the system, paralyzes the bodily functions, 

 and causes death. 



Given that there is time, an injection of the 

 antitoxin causes the body to rally against the 

 poison; the patient recovers. In many instances 

 there is recovery when no antitoxin has been 

 administered. What is the process? 



More than a decade ago Elias Metchnikoff, the 

 eminent Russian pathologist, undertook an ex- 



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