THE SUCCESSORS OF VESALIUS 41 



teaching. He was no great theorist but was a most 

 stimulating teacher. Above all, he taught his pupils to 

 observe with their own eyes. He would deserve our 

 remembrance if only as the master of the effective dis- 

 coverer of the circulation, William Harvey. It is of 

 interest, therefore, to ascertain what Fabricius was 

 actually saying about respiration, a subject so nearly 

 bound up with the problem of the heart's actions. We 

 may learn the views of Fabricius on this topic from his 

 work On Respiration and its Mechanism, printed in 1603. 

 This book still contains the old Galenic physiological 

 system almost unaltered. 



In his summing up he tells us : "In respiration, Nature 

 sets herself a double end, the generation of animal spirits 

 and the regulation and maintenance of the innate heat. 

 The heat is regulated by [a relation between] the fuel 

 supplied, refrigeration [by the lung], and the elimination 

 of the superfluities. All these are the result of the air 

 taken into the body, whence the necessity for respiration. 

 . . . Respiration is the movement of air by which spirit 

 is taken in and given out through the mouth. In in- 

 spiration air enters the lung and the heart, carrying 

 material and coldness ; in expiration, on the other hand, 

 the superfluous residues are evacuated." The innate 

 heat of the heart was thus even more of a reality to 

 Fabricius than to Galen, and he is back again on 

 the Aristotelian view. Thus he says that " the heart 

 burns as with a flame." He does not even accept the 

 lesser circulation as demonstrated by Servetus and by 

 Columbus, his predecessor as teacher at Padua. 



