AN ANATOMICAL STUDY ON THE 



These and other similar inconveniences beset the 

 traditional opinions about the pulse and the func- 

 tions of the arteries. Those maintained on the func- 

 tion and beat of the heart are perhaps no less in- 

 volved in many tangled difficulties. The heart is 

 commonly said to be the source and factory of the 

 vital spirits, from which life is given to the different 

 portions of the body, yet that the right ventricle 

 makes spirits is denied, — it merely gives nourishment 

 to the lungs. So it is said that the right ventricle of 

 the heart is lacking in fishes (indeed in all animals 

 in which there are no lungs), and that the right 

 ventricle exists for the sake of the lungs. 



1. The structure of both ventricles is practically 

 the same. There is the same fabric of fibers, braces, 

 valves, vessels, auricles, and both on section are 

 filled with similar dark colored and coagulated 

 blood. Why, then, should we imagine their func- 

 tions to be so different when the action, movement, 

 and beat of both are the same? The three tricuspid 

 valves at the entrance to the right ventricle are a 

 hindrance to the return of blood into the vena cava. 

 The three semilunar valves at the opening of the 

 pulmonary artery are placed to prevent back flow 

 of blood. Why, then, when there are similar struc- 

 tures in the left ventricle, should we deny them a 

 similar purpose, of hindering at one place the 

 escape, at the other the reflux of the blood? 



2. When the size, shape, and position of these 

 structures are almost the same in the left ventricle 



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