MOTION OF THE HEART AND BLOOD 



is the case in all animals lacking lungs, Nature was 

 compelled, when she wished to filter blood through 

 the lungs, to add the right ventricle, whose beat 

 should force blood from the vena cava through 

 the lungs into the left ventricle. Thus the right 

 ventricle may be said to be made for the sake of 

 transmitting blood through the lungs, not for 

 nourishing them. It is entirely unreasonable to 

 assume that the lungs need so much more abundant 

 nutriment, and coming directly from the heart, so 

 much purer and more spiritous blood than either 

 the very refined substance of the brain, or the very 

 brilliant and perfect structure of the eyes, or the 

 flesh of the heart itself which is adequately nourished 

 by the coronary artery. 



68 I 



