THE FRONTIERS OF MEDICINTE 



fact that germs cause disease, brought about control of 

 the acute infectious diseases. It became possible to prevent 

 their transmission from one person to another and to stop 

 the devastating plagues which used to wipe out entire 

 communities. Infections could be avoided through in- 

 oculation. 



Associated with this knowledge came new concentration 

 on the blood as the important medium in the human body 

 for aiding resistance to disease and for taking care of 

 disease conditions when they develop. Obviously, new 

 machines had to be devised for all of these purposes, since 

 the objects with which one deals are microscopic in size, 

 some of them even too small to be seen by the finest 

 microscope. 



As a result of this new knowledge, medicine began to 

 divide itself into branches, many of which were concerned 

 with special ability to use particular instruments. The 

 technic of employing these new devices was, in itself, 

 an art to be acquired only by long practice. Moreover, 

 one was concerned not only with the application of such 

 technic, but also with a knowledge of things seen and 

 heard by the use of the newer apparatus and an interpreta- 

 tion of these observations in the light of our information 

 on disease. 



Internal Medicine. The specialist in internal medicine 

 concerns himself with disturbances affecting the heart 

 and lungs, the circulation, the organs within the abdomen, 

 digestive disorders, degenerative disorders, and other 

 complications of human physiology, which are puzzling 

 to the general practitioner. In the diagnosis of heart con- 

 ditions, it is possible for any general practitioner who 

 has kept himself up-to-date to determine whether or not 

 diseases of the heart are present, to determine — in general — 

 the nature of that disease, and the competency of the pa- 

 tient to perform certain work. 



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