CIRCULATION OF THE BLOOD. 99 



such a bias rather than rigidly and in behalf of the simple truth. 

 This is also apparent when he would have the blood to make its 

 way into the left ventricle through the septum of the heart, by 

 certain invisible and unknown passages, rather than through 

 those ample and abundantly pervious channels, the pulmonary 

 vessels, furnished with valves, opposing all reflux or regurgitation. 

 He informs us that he has elsewhere discussed the reasons of 

 the impossibility or inconvenience of this : I much desire to see 

 his disquisition. It would be extraordinary, indeed, were the 

 aorta and pulmonary artery, with the same dimensions, proper- 

 ties, and structure, not to have the same functions. But it 

 would be more wonderful still were the whole tide of the blood 

 to reach the left ventricle by a set of inscrutable passages of the 

 septum, a tide which, in quantity must correspond, first to the 

 influx from the vena cava into the right side of the heart, 

 and next to the efflux from the left, both of which require such 

 ample conduits. But our author has adduced these matters 

 inconsistently, for he has established the lungs as an emunctory 

 or passage from the heart; 1 and he says: " The lung is affected 

 by the blood which passes through it, the sordes flowing along 

 with the blood." And, again : " The lungs receive injury from 

 distempered and ill-conditioned viscera; these deliver an impure 

 blood to the heart, which it cannot correct except by multiplied 

 circulations." In the same place, he further proceeds, whilst 

 speaking against Galen of bloodletting in peripneumonia and 

 the communication of the veins : " Were it true that the blood 

 naturally passed from the right ventricle of the heart to the 

 lungs, that it might be carried into the left ventricle and from 

 thence into the aorta; and were the circulation of the blood 

 admitted, who does not see that in affections of the lungs the 

 blood would flow to them in larger quantity and would oppress 

 them, unless it were taken away, first, freely, and then in re- 

 peated smaller quantities in order to relieve them, which indeed 

 was the advice of Hippocrates, who, in affections of the lungs 

 takes away blood from every part the head, nose, tongue, 

 arms and feet, in order that its quantity may be diminished 

 and a diversion effected from the lungs ; he takes away blood 

 till the body is almost bloodless. Now admitting the circu- 



1 Lib. iii, cap. C. 



