Chapter X 



The First Proposition, Concerning the Amount 



of Blood Passing from Veins to Arteries, 



During the Circulation of the Blood, 



is Freed from Objections, and 



Confirmed by Experiments 



WHETHER the matter be referred to cal- 

 culation or to experiment and dissection, 

 the important proposition has been established that 

 blood is continually poured into the arteries in a 

 greater amount than can be supplied by the food. 

 Since it all flows past in so short a time, it must be 

 made to flow in a circle. 



Someone may say here that a great amount may 

 flow out without any necessity for a circulation 

 and that it all may come from the food. An ex- 

 ample might be given in the rich milk supply of the 

 mammae. A cow may give three or four, or even 

 seven and more gallons of milk daily, and a mother 

 two or three pints when nursing a baby or twins, 

 all of which must obviously come from the food. 

 It may be replied that the heart, by computation, 

 does more in an hour or less. 



Not yet persuaded, one may still insist that cut- 

 ting an artery opens a very abnormal passage through 



[8i] 



