HARVEY'S WORK 57 



tained nothing but spirits during the life of an animal. 1 

 The true cause of the difference is this, that there is no 

 passage to the arteries, save through the lungs and heart. 

 When an animal has ceased to breathe and the lungs 

 to move, the blood in the arterial vein [pulmonary artery] 

 is prevented from passing into the venal artery [pulmonary 

 vein] and from thence into the left ventricle of the heart. 

 . . . But the heart not ceasing to act at the same precise 

 moment as the lungs, but surviving them and continuing 

 to pulsate for a time, the left ventricle and the arteries 

 go on distributing their blood to the body at large and 

 sending it into the veins ; receiving none from the lungs, 

 however, they are soon exhausted, and left empty." This 

 is the reason why after death the arteries are often empty 

 and the veins full. 



He terminates this matter by remarking : We are 

 now in a condition to suspect why no one has yet said 

 anything to the purpose upon the anastomosis of veins 

 and arteries, either whether or how it is effected or for 

 what purpose. I now enter on an investigation of that 

 subject." 



(c) SOME CRUCIAL EXPERIMENTS 



13. He proceeds to examine serpents, which have the 

 advantage that the heart continues to pulsate long after 

 the animal is dead. In serpents, too, the great blood- 

 vessels are very conveniently arranged for observation. 

 He remarks that when a serpent is laid open and the 

 vena cava is seized with forceps and the course of the 

 blood below the heart thus interrupted, the part that 

 intervenes between the forceps and the heart almost 

 immediately becomes empty. At the same time the 



1 The word artery is known in Greek in the form aprypia, arteria, and, 

 like the word aorta, is derived from a.elpei.v, deirein, to raise or lift up. 

 Some of the Greeks themselves derived it from drjp, aer, meaning air, 

 and Harvey shared in their error. 



