Sources of Pathology. 7 



hypothesis-building science on the other. The learned doctors, with 

 their schools of practically nothing more than mere dogma, who 

 had no acquaintance with the structure and vital functions of the 

 body save what could be gained from its exterior, knew little more 

 than the charlatans of their times. \'eterinary medicine was prac- 

 ticed bv butchers, farriers and grooms, wdiose information and 

 practical knowledge were based upon the doctrines, conceptions 

 and reci]ies handed down from former generations. 



At the present time clinical observation is no longer limited to 

 the mere detection of the external signs of disease, but seeks an 

 explanation for them, searches for evidence of the internal morbid 

 processes and for the precise location and for the causes of disease, 

 calling to its aid every means of anatomical and physiological in- 

 vestigation and contributing materially to the complete develop- 

 mental history of disease. 



In point of time the real development of pathological science 

 corresponds with the period when first the study of the exact loca- 

 tion of disease was begun with the aid of the dissecting scalpel and 

 the microscope. jMorbid anatomy came to be recognized as the 

 foundation stone of scientific medicine, and remains the most im- 

 portant landmark in experimental studies. It was recognized that 

 definite symptoms are related with certain structural alterations, 

 that it is possible to make inferences as to the altered state and 

 structure of the organs from given disturbances of function, and 

 that the symptomatologv of a case may thus furnish a basis for 

 the anatomical diagnosis and the anatomical conception of the dis- 

 ease in hand. IMany of the alterations of disease are of such a 

 character that the position, shape, consistence, color, weight and 

 contents of the parts affected are strikingly dififerent from the 

 characteristics in health, and even the unaided eye sees at once 

 whv svmptoms must have been induced ; and from the study of 

 such evidence afforded by the dead bodies of diseased human beings 

 and animals there has been accumulated a large amount of data ana 

 statistics toward the establishment of a clear insight into the develop- 

 ment, cause and termination of disease. Visceral anatomy along 

 with visceral phvsiology has taught us what we know of the prin- 

 ciples governing the action of the heart, the circulation of the blood, 

 atmospheric interchange in the lungs, the functions of the digestive 

 and urogenital tracts, and no little part of the pathology of the 

 sensory organs ; and it is quite possible for one to draw conclusions 

 from given anatomical changes how the mechanism of the grosser 



