Heart and Blood 69 



else, do the arteries pulsate, at the same time that 

 immediately above the ligature the artery begins to rise 

 higher at each diastole, to throb more violently, and to 

 swell in its vicinity with a kind of tide, as if it strove to 

 break through and overcome the obstacle to its current ; 

 the artery, here, in short, appears as if it were preter- 

 naturally full. The hand under such circumstances 

 retains its natural colour and appearance ; in the course 

 of time it begins to fall somewhat in temperature, in- 

 deed, but nothing is drawn into it. 



After the bandage has been kept on for some short 

 time in this way, let it be slackened a little, brought to 

 that state or term of middling tightness which is used 

 in bleeding, and it will be seen that the whole hand 

 and arm will instantly become deeply suffused and 

 distended, and the veins show themselves tumid and 

 knotted ; after ten or fifteen pulses of the artery, the 

 hand will be perceived excessively distended, 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 indicated. 



If the finger be applied over the artery as it is pul- 

 sating by tlfe edge of the fillet, at the moment of 

 slackening it, the blood will be felt to glide through, 

 as it were, underneath the finger ; and he, too, upon 

 whose arm the experiment is made, when the ligature 

 is slackened, is distinctly conscious of a sensation of 

 warmth, and of something, viz. a stream of blood, 

 suddenly making its w r ay along the course of the 

 vessels and diffusing itself through the hand, which 

 at the same time begins to feel hot, and becomes 

 distended. 



As we had noted, in connexion 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, 

 whilst the arteries shrink ; and such is the degree of 



