AN ANATOMICAL STUDY ON THE 



the artery firmly pressing its tunics against the 

 tube you will see the artery does not beat as fully 

 beyond the noose." I have neither made this experi- 

 ment of Galen's, nor do I believe it can be done 

 easily in the living body because of the excessive 

 loss of blood from the artery. I doubt that the 

 tube would close up the wound without a ligature, 

 and that blood would not burst out between the 

 tube and the vessel. Yet Galen seems to prove** by 

 this experiment both that the pulsating power 

 passes from the heart through the walls of the ar- 

 teries, and that the arteries while dilating are filled 

 by this pulsating power since they dilate like a 

 bellows and do not distend because they are filled 

 like a leather bottle. 



The contrary, however, Is apparent in arteriotomy 

 and wounds, the blood leaping from the artery 

 rushes out with force, first farther, then nearer, 

 alternately in spurts, the spurt being always during 

 the distention of the artery, never during its con- 

 tracture. From this it is obvious that the artery 

 is distended by the impulse of blood, for it is im- 

 possible for it per se to throw the blood with such 

 force while dilating, — it should rather be drawing 

 air into itself through the wound, according to the 

 common ideas on the functions of the arteries. 



^ A little unfair to Galen (131-201 A.D.). Not only was the experi- 

 ment not tried, but unwarranted conclusions are unjustly ascribed to 

 him. This simile of the bellows and leather bottle is frequently used by 

 Harvey. 



[14] 



