Heart and Blood 61 



transfused from the veins to the arteries. The actual 

 quantity of blood expelled at each stroke of the heart, 

 and the circumstances under which it is either greater 

 or less than ordinary, I leave for particular determination 

 afterwards, from numerous observations which I have 

 made on the subject. 



Meantime this much I know, and would here pro- 

 claim to all, that the blood is transfused at one time 

 in larger, at another in smaller quantity ; and that the 

 circuit of the blood is accomplished now more rapidly, 

 now more slowly, according to the temperament, age, 

 &c., of the individual, to external and internal circum- 

 stances, to naturals and non-naturals, sleep, rest, food, 

 exercise, affections of the mind, and the like. But 

 indeed, supposing even the smallest quantity of blood 

 to be passed through the heart and the lungs with 

 each pulsation, a vastly greater amount would still be 

 thrown into the arteries and whole body, than could 

 by any possibility be supplied by the food consumed ; 

 in short it could be furnished in no other way than by 

 making a circuit and returning. 



This truth, indeed, presents itself obviously before 

 us when we consider what happens in the dissection of 

 living animals ; the great artery need not be divided, 

 but a very small branch only, (as Galen even proves in 

 regard to man,) to have the whole of the blood in the 

 body, as well that of the veins as of the arteries, drained 

 away in the course of no long time some half-hour or 

 less. Butchers are well aware of the fact and can bear 

 witness to it ; for, cutting the throat of an ox and so- 

 dividing the vessels of the neck, in less than a quarter 

 of an hour they have all the vessels bloodless the 

 whole mass of blood has escaped. The same thing 

 also occasionally occurs with great rapidity in per- 

 forming amputations and removing tumours in the 

 human subject. 



Nor would this argument lose any of its force, did 

 any one say that in killing animals in the shambles, and 



