Chapter VII 



The Passage of Blood Through the Substance 



of the Lungs from the Right Ventricle 



of the Heart to the Pulmonary 



Vein and Left Ventricle 



THAT this may be so, and that there is nothing 

 to keep it from being so, is evident when we con- 

 sider how water filtering through the earth forms 

 springs and rivers, or when we speculate on how sweat 

 goes through the skin, or urine through the kidneys. 

 It is well known that those who use Spa waters, or 

 those of La Madonna near Padua, or other acid 

 waters which are drunk by the gallon, pass them all 

 off in an hour or so by the bladder. So much fluid 

 must tarry a while in the digestive tract, it must pass 

 through the liver (everyone agrees that the alimentary 

 succus goes through this organ at least twice daily),* 

 through the veins, the substance of the kidneys, and 

 through the ureters into the bladder. 



I know there are those who deny that the whole 

 mass of blood may pass through the lungs as the 

 alimentary juices filter through the liver, saying it is 



^ I can't trace the origin of this quaint notion. Perhaps it refers 

 to the two chief meals of the day. 



[6ij 



