GALEN. 57 



as the heart by its diastole drew its charge from the vena 

 cava and the pulmonary vein. The pulse of the arteries, 

 he also thought, was propagated by their coats, not by 

 the wave of blood thrown into them by the heart. He 

 taught that at every systole of the arteries a certain 

 portion of their contents was discharged at their ex- 

 tremities, namely, by the exhalents and secretory vessels. 

 Though he demonstrated the anastomosis of arteries and 

 veins, he nowhere hints his belief that the contents of the 

 former pass into the latter, to be conveyed back to the 

 heart, and from it to be again diffused over the body. 

 He made a near approach to the Harveian theory of 

 the circulation, as Harvey himself admits in his " De 

 Motu Cordis;" 1 but the grand point of difference between 

 Galen and Harvey is the question whether or not, at 

 every systole of the left ventricle, more blood is thrown 

 out than is expended on exhalation, secretion, and 

 nutrition. Upon this point Galen held the negative, 

 and Harvey, as we all know, the affirmative. 



The famous Asclepiads held that respiration was for 

 the generation of the soul itself, breath and life being 

 thus considered to be identical. Hippocrates thought 

 it was for the nutrition and refrigeration of the innate 



1 "Ex ipsius etiam Galeni verbis hanc veritatem confirmari posse, 

 scilicet : non solum posse sanguinem e vena arteriosa in arteriam 

 venosam et inde in sinistrum ventriculum cordis, et postea in 

 arterias transmitti." " De Motu Cordis," cap. vii, 



