MOTION OF THE HEART AND BLOOD 



above the ligature unless it is completely loosened. 

 Then we see the veins suddenly collapse, discharg- 

 ing themselves to the part above, the hand loses 

 its flush, and the stagnant blood and swelling quickly 

 fade away. 



Further, he whose arm has been bound for some 

 time with a medium bandage, and whose hand has 

 been rendered somewhat swollen and cold, feels, 

 as the ligature is loosened, something cold creeping 

 up with the returning blood to the elbow or arm- 

 pit. I think this cold blood returning to the heart, 

 after removing the bandage in blood-letting, is a 

 cause of fainting, which we sometimes see even in 

 robust persons, usually when the ligature is removed, 

 or, as is commonly said, when the blood turns. 



Moreover, immediately on loosening a tight 

 bandage to a medium one, we see the veins below 

 it, but not the arteries, swollen with blood contin- 

 ually carried in by the arteries. This indicates that 

 blood passes from arteries to veins, not the reverse, 

 and that there is either an anastomosis of these 

 vessels or pores in the flesh and solid parts per- 

 meable to blood. It also indicates that the veins 

 inter-communicate, since, with a medium ligature 

 above the elbow, they all swell up at the same time, 

 and, if even a single venule be cut with a lancet, 

 they all quickly shrink, giving up their blood to 

 this one, and subside almost together. 



Anyone may understood from this the reasons 

 for the ''drawing" power existing in ligatures, and 



[89] 



