yo Motion of the 



distension 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 every careful observer 

 to learn that the blood enters an extremity by the 

 arteries ; for when they are effectually compressed 

 nothing is drawn to the member ; the hand preserves 

 its colour ; 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 where they 

 do not pulsate, as when a tight ligature is used, they 

 cease from transmitting anything; they are only dis- 

 tended 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 than 

 above it, and than they usually appear when there is no 

 bandage upon the arm. 



It therefore plainly appears that the ligature prevents 

 the return of the blood through the veins to the parts 

 above it, and maintains those beneath it in a state of 

 permanent distension. But the arteries, in spite of its 

 pressure, and under the force and impulse of the heart, 

 send on the blood from the internal parts of the body 

 to the parts beyond the bandage. And herein consists 

 the difference between the tight and the medium 

 bandage, that the former not only prevents the passage 

 of the blood in the veins, but in the arteries also ; the 

 latter, however, whilst it does not prevent the pulsific 

 force from extending beyond it, and so propelling the 

 blood to the extremities of the body, compresses the 

 veins, and greatly or altogether impedes the return of 

 the blood through them. 



