68 MOTION OF THE 



CHAPTER XIV. 



CONCLUSION OF THE DEMONSTRATION OF THE CIRCULATION. 



AND now I may be allowed to give in brief my view of the 

 circulation of the blood, and to propose it for general adoption. 



Since all things, both argument and ocular demonstration, 

 show that the blood passes through the lungs and heart by the 

 action of the [auricles and] ventricles, and is sent for distri- 

 bution to all parts of the body, where it makes its way into the 

 veins and pores of the flesh, and then flows by the veins from the 

 circumference on every side to the centre, from the lesser to 

 the greater veins, and is by them finally discharged into the 

 vena cava and right auricle of the heart, and this in such a quan- 

 tity or in such a flux and reflux thither by the arteries, hither 

 by the veins, as cannot possibly be supplied by the ingesta, 

 and is much greater than can be required for mere purposes of 

 nutrition; it is absolutely necessary to conclude that the blood 

 in the animal body is impelled in a circle, and is in a state of 

 ceaseless motion; that this is the act or function which the heart 

 performs by means of its pulse ; and that it is the sole and only 

 end of the motion and contraction of the heart. 



CHAPTER XV. 



THE CIRCULATION OF THE BLOOD IS FURTHER CONFIRMED BY 

 PROBABLE REASONS. 



IT will not be foreign to the subject if I here show further, 

 from certain familiar reasonings, that the circulation is matter 

 both of convenience and necessity. In the first place, since 

 death is a corruption which takes place through deficiency of 

 heat, 1 and since all living things are warm, all dying things 

 cold, there must be a particular seat and fountain, a kind of 

 home and hearth, where the cherisher of nature, the original 

 of the native fire, is stored and preserved ; whence heat 

 and life are dispensed to all parts as from a fountain head; 



1 Aristoteles De Respiratione, lib. ii et iii : De Part. Animal, et alibi. 



