

i] His Forerunners and Followers. 23 



" vapour shining out of the purer blood containing the sub- 

 " stance of water, of air and of fire. It is generated through 

 "the commingling which is effected in the lungs of the 

 "inspired air with the elaborated subtle blood communicated 

 "from the right ventricle to the left. That communication 

 " does not, however, as is generally believed, take place through 

 " the median wall (septum) of the heart, but by a signal artifice 

 "the subtle blood is driven by a long passage through the 

 " lungs. It is prepared by the lungs, is rendered yellow (light) 

 " and from the artery-like vein is poured into the vein-like 

 " artery. Then in the vein-like artery it is mixed with the 

 " inspired air, and by expiration is cleansed from its fumes. 

 " And so at length it is drawn in, a complete mixture, by the 

 " left ventricle through the Diastole, stuff fit to become the 

 " vital spirit. 



" That the communication and preparation does take place 

 " in this way through the lungs is shewn by the manifold 

 "conjunction and communication of the artery-like vein with 

 " the vein-like artery. 



"This view is confirmed by the conspicuous size of the 

 " artery-like vein which would not have been made so large 

 " and so stout, and would not discharge from the heart itself such 

 "a power of very pure blood into the lungs for the mere 

 " purpose of nourishing these organs. Nor would the heart 

 " serve the lungs in this manner, especially since at an earlier 

 " date in the embryo on account of the little membranes of the 

 "heart, the lungs themselves are up to the hour of birth 

 "nourished from other sources, as Galen teaches." 



These words shew beyond all possible doubt that Servetus 

 rejected wholly and unreservedly the hypothetical passage of 

 the blood through the septum ; he went far beyond the merely 

 hinted scepticism of Vesalius. They further shew that he had 

 grasped the true features of the pulmonary circulation, the 

 passage of the blood from the right side through the lungs to 

 the left side. He must have attained these results by his own 

 unaided inquiry and thought ; and had he given to science the 

 labours which he gave to theology, he obviously might have 

 deserved the title of one of the great anatomists of the time. 



