I 



THE BLOOD 



I. — Before Harvey 



ALEN, born at Pergamos, 131 a.d., proved by 



experiments on animals that the brain is as 

 warm as the heart, against the Aristotelian doctrine 

 that the office of the brain is to keep the heart 

 cool. He also proved that the arteries during life 

 contain blood, not irvev^a, or the breath of life : — 



" Ourselves, having tied the exposed arteries 

 above and below, opened them between the liga- 

 tures, and showed that they were indeed full of 

 blood." 



Though all vessels bleed when they are 

 wounded, yet this experiment was necessary to 

 refute the fanciful teaching of Erasistratus and 

 his followers, of whom Galen says :■ — 



" Erasistratus is pleased to believe that an 

 artery is a vessel containing the breath of life, 

 and a vein is a vessel containing blood ; and that 



3 



