EVOLUTION AND DISEASE. 



INTRODUCTION. 



MOST persons believe Pathology, as the Science of 

 Disease is called, to be so outside the comprehension 

 of ordinary individuals, and even in its general bearings 

 so utterly devoid of interest to all but medical men, that 

 much misconception prevails in the minds of even 

 educated persons in regard to its fundamental principles. 

 As a matter of fact Pathology is only a department of 

 Biology, and it is very important to bear this in mind if 

 we wish to study successfully the origin, cause, and 

 spread of disease. Yet paradoxical as it seems, whilst so 

 many regard Pathology as occupying an isolated position 

 among sciences, medical writers always point out the 

 difficulty they find in framing a definition of disease, and 

 indeed the impossibility of stating where health ends and 

 disease begins. 



It is not my object in the present work to attempt the 

 framing of a definition of disease, or even to offer a 

 suggestion as to the borderland between it and health, 

 This difficulty is frequently illustrated in a striking 

 manner in a law court ; it is not uncommon for a judge 



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