40 Motion of the 



" You will reply," he says, " that the effect is so ; that 

 the blood is prepared in the liver, and is thence 

 transferred to the heart to receive its proper form and 

 Jast perfection ; a statement which does not appear 

 devoid of reason ; for no great and perfect work is 

 -ever accomplished at a single effort, or receives its final 

 polish from one instrument. But if this be actually so, 

 then show us another vessel which draws the absolutely 

 perfect blood from the heart, and distributes it as the 

 arteries do the spirits over the whole body." Here 

 then is a reasonable opinion not allowed, because, 

 forsooth, besides not seeing the true means of transit, 

 he could not discover the vessel which should transmit 

 the blood from the heart to the body at large ! 



But had any one been there in behalf of Erasistratus, 

 and of that opinion which we now espouse, and which 

 Galen himself acknowledges in other respects consonant 

 with reason, to 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 

 ihe 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 Erasistratus, 

 to wit, that blood in substance is contained in the 

 arteries, and not spirits ; a fact which he demonstrated 

 not only by many powerful arguments, but by ex- 

 periments. 



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 



