MOTION OF THE HEART AND BLOOD 



how and when do they take in blood from the heart? 

 During systole is impossible: the arteries would 

 have to fill while contracted, or to fill and not be- 

 come distended. During diastole is improbable: 

 they would then receive for two contrary purposes 

 both blood and air, and heat and cold. 



Further, when it is stated that the diastole of 

 the heart and arteries is simultaneous, and the 

 systole likewise, there is another inconsistency. 

 How can two bodies being connected together and 

 being distended at the same time draw anything 

 one from the other? Or being contracted simul- 

 taneously receive anything one from the other? 

 Moreover, it seems impossible that one body may 

 thus draw another body to itself in order to become 

 distended, since distention is passive, unless return 

 is made to a natural state, like a sponge previously 

 compressed by external force. It is hard to imagine 

 anything like this in the arteries. 



The arteries distend because they are filled like 

 bladders or pouches and they are not filled because 

 they expand like a bellows, as I have easily and 

 clearly shown, and proved, I think, ere this. How- 

 ever, in Galen's book, ^uod sang. cont. in Arter,^ 

 there is an experiment to show the opposite: an 

 artery is exposed and cut longitudinally, and a reed 

 or hollow tube is inserted through the opening, so 

 the wound is closed and the blood not driven out. 

 "As long as it stays thus," he says, "the whole 

 artery will pulsate, but if you tie a thread around 



[13] 



