Chapter XI 

 The Second Proposition is Proven 



^UR second proposition may appear more clearly 

 by considering certain experiments from which 

 it is obvious that blood enters a limb through the 

 arteries and returns through the veins, that the 

 arteries are the vessels carrying blood from the 

 heart and the veins the channels returning it to 

 the heart, and that, in the extremities, blood passes 

 from arteries to veins directly by anastomosis or 

 indirectly through pores in the flesh, as discussed 

 before in regard to its transfer from veins to arteries 

 in the heart and thorax. From this it may be clear 

 that it moves in a circle from the center to the extremi- 

 ties and back from the extremities to the center. 



Then, making certain calculations, it will also 

 be clear that the quantity may neither be supplied 

 from the food taken in nor necessarily be required 

 for nutrition. 



These experiments will also clear up some points 

 regarding ligatures: why they may cause swelling, 

 which is neither by heat nor suction nor any reason 

 yet known; what uses and advantages may be 

 obtained from them in practice; how they may 

 either suppress or provoke hemorrhage; how they 



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