CHAPTER XII 



THAT THERE IS A CIRCULATION OF THE BLOOD IS 

 SHOWN FROM THE SECOND POSITION DEMONSTRATED 



IF these things be so, another point which I have 

 already referred to, viz. the continual passage of the 

 blood through the heart, will also be confirmed. We 

 have seen, that the blood passes from the arteries into 

 the veins, not from the veins into the arteries ; we 

 have seen, farther, that almost the whole of the blood 

 may be withdrawn from a puncture made in one of 

 the cutaneous veins of the arm if a bandage properly 

 applied be used ; we have seen, still farther, that the 

 blood flows so freely and rapidly that not only is the 

 whole quantity which was contained in the arm beyond 

 the ligature, and before the puncture was made, dis- 

 charged, but the whole which is contained in the body, 

 both that of the arteries and that of the veins. 



Whence we must admit, first, that the blood is sent 

 along with an impulse, and that it is urged with force 

 below the fillet ; for it escapes with force, which force 

 it receives from the pulse and power of the heart ; 

 for the force and motion of the blood are derived from 

 the heart alone. Second, that the afflux proceeds from 

 the heart, and through the heart by a course from the 

 great veins [into the aorta] ; for it gets into the parts 

 below the ligature through the arteries, not through 

 the veins; and the arteries nowhere receive blood 

 from the veins, nowhere receive blood save and except 

 from the left ventricle of the heart. Nor could so 

 large a quantity of blood be drawn from one vein 



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