94 WILLIAM HARVEY 



have pointed to the aorta as the vessel which distributes the 

 blood from the heart to the rest of the body, I wonder what 

 would have been the answer of that most ingenious and 

 learned man? Had he said that the artery transmits spirits 

 and not blood, he would indeed sufficiently have answered 

 Erasistratus, who imagined that the arteries contained 

 nothing but spirits; but then he would have contradicted 

 himself, and given a foul denial to that for which he had 

 keenly contended in his writings against this very Erasistra- 

 tus, to wit, that blood in substance is contained in the arter- 

 ies, and not spirits; a fact which he demonstrated not only 

 by many powerful arguments, but by experiments. 



But if the divine Galen will here allow, as in other places 

 he does, "that all the arteries of the body arise from the 

 great artery, and that this takes its origin from the heart; 

 that all these vessels naturally contain and carry blood; that 

 the three semilunar valves situated at the orifice of the aorta 

 prevent the return of the blood into the heart, and that 

 nature never connected them with this, the most noble viscus 

 of the body, unless for some important end"; if, I say, this 

 father of physicians concedes all these things, and I quote 

 his own words, I do not see how he can deny that the 

 great artery is the very vessel to carry the blood, when it 

 has attained its highest term of perfection, from the heart 

 for distribution to all parts of the body. Or would he per- 

 chance still hesitate, like all who have come after him, even 

 to the present hour, because he did not perceive the route 

 by which the blood was transferred from the veins to the 

 arteries, in consequence, as I have already said, of the 

 intimate connexion between the heart and the lungs? And 

 that this difficulty puzzled anatomists not a little, when in 

 their dissections they found the pulmonary artery and left 

 ventricle full of thick, black, and clotted blood, plainly 

 appears, when they felt themselves compelled to affirm that 

 the blood made its way from the right to the left ventricle 

 by transuding through the septum of the heart. But this 

 fancy I have already refuted. A new pathway for the blood 

 must therefore be prepared and thrown open, and being once 

 exposed, no further difficulty will, I believe, be experienced 

 by anyone in admitting what I have already proposed in 







