12 On the Heart and Blood 



although some affirm that the lungs, arteries, and heart 

 have all the same offices, they yet maintain that the 

 heart is the workshop of the spirits, and that the arteries 

 contain and transmit them ; denying, however, in oppo- 

 sition to the opinion of Columbus, that the lungs can 

 either make or contain spirits ; and then they assert, 

 with Galen, against Erasistratus, that it is blood, not 

 spirits, which is contained in the arteries. 



These various opinions are seen to be so incongruous 

 and mutually subversive, that every one of them is not 

 unjustly brought under suspicion. That it is blood and 

 blood alone which is contained in the arteries is made 

 manifest by the experiment of Galen, by arteriotomy, 

 and by wounds ; for from a single artery divided, as 

 Galen himself affirms in more than one place, the whole 

 of the blood may be withdrawn in the course of half 

 an hour, or less. The experiment of Galen alluded to is 

 this : " If you include a portion of an artery between 

 two ligatures, and slit it open lengthways, you will find 

 nothing but blood;" and thus he proves that the arteries 

 contain blood only. And we too may be permitted to 

 proceed by a like train of reasoning : if we find the same 

 blood in the arteries that we find in the veins, which we 

 have tied in the same way, as I have myself repeatedly 

 ascertained, both in the dead body and in living animals, 

 we may fairly conclude that the arteries contain the same 

 blood as the veins, and nothing but the same blood. 

 Some, whilst they attempt to lessen the difficulty here, 

 affirming that the blood is spirituous and arterious, 

 virtually concede that the office of the arteries is to 

 carry blood from the heart into the whole of the body, 

 and that they are therefore filled with blood ; for 

 spirituous blood is not the less blood on that account. 

 And then no one denies that the blood as such, even 

 the portion of it which flows in the veins, is imbued with 

 spirits. But if that portion which is contained in the 

 arteries be richer in spirits, it is still to be believed that 

 these spirits are inseparable from the blood, like those 



