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 circu- 

 lation 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 ; whence sustenance may be derived ; and upon 

 which concoction and nutrition, and all vegetative energy 

 may depend. Now, that the heart is this place, that the 

 heart is the principle of life, and that all passes in the 

 manner just mentioned, I trust no one will deny. 



The blood, therefore, required to have motion, and 

 indeed such a motion that it should return again to the 

 heart ; for sent to the external parts of the body far from 

 its fountain, as Aristotle says, and without motion, it 

 would become congealed. P'or we see motion generating 

 and keeping up heat and spirits under all circumstances, 

 and rest allowing them to escape and be dissipated. 

 The blood, therefore, become thick or congealed by the 

 cold of the extreme and outward parts, and robbed of 

 its spirits, just as it is in the dead, it was imperative 

 that from its fount and origin, it should again receive 



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



86 



