FROM PARACELSUS TO HARVEY 



arm will instantly become deeply suffused and distend- 

 ed, injected, gorged with blood, drawn, as it is said, 

 by this middling ligature, without pain, or heat, or 

 any horror of a vacuum, or any other cause yet in- 

 dicated. 



"As we have noted, in connection with the tight 

 ligature, that the artery above the bandage was 

 distended and pulsated, not below it, so, in the case 

 of the moderately tight bandage, on the contrary, do 

 we find that the veins below, never above, the fillet 

 swell and become dilated, while the arteries shrink; 

 and such is the degree of distention of the veins here 

 that it is only very strong pressure that will force the 

 blood beyond the fillet and cause any of the veins in 

 the upper part of the arm to rise. 



" From these facts it is easy for any careful observer 

 to learn that the blood enters an extremity by the 

 arteries; for when they are effectively compressed 

 nothing is drawn to the member; the hand preserves 

 its color ; nothing flows into it, neither is it distended ; 

 but when the pressure is diminished, as it is with the 

 bleeding fillet, it is manifest that the blood is instantly 

 thrown in with force, for then the hand begins to swell ; 

 which is as much as to say that when the arteries 

 pulsate the blood is flowing through them, as it is 

 when the moderately tight ligature is applied; but 

 when they do not pulsate, or when a tight ligature is 

 used, they cease from transmitting anything; they 

 are only distended above the part where the ligature is 

 applied. The veins again being compressed, nothing 

 can flow through them ; the certain indication of which 

 is that below the ligature they are much more tumid 



177 



