THE CIRCULATION OF THE BLOOD. 271 



I have seen- a case of this kind, where a young lady of this 

 city, was kept a fortnight after she was supposed to have 

 died ; her looks being so natural that her parents were un- 

 willing to bury her, for fear she would come to life. Al- 

 though she lay in a room without a fire in the winter season, 

 yet her body retained its natural warmth for several days, 

 her cheeks their florid colour, and her limbs their usual flex, 

 ibility. These singular phenomena were perhaps owing to 

 a continuance of the capillary circulation. 



f \ 



40 .(The capillary vessels Vre the last part of the body that 

 continues to act. After the breathing and the action of the 

 heart have ceased, they still continue to act like innumera- 

 ble little pumps, drawing the blood out of the arteries and 

 substance of the organs, and forcing it into the veins. As 

 nutrition and secretion are performed by that portion of the 

 capillary system which acts independently of the heart and 

 arteries, the continuance of action in this system accounts 

 for the growth of the beard and the hair, which takes place 

 after death. It is owing to *he same reason, that the arte- 

 ries are always found empty after death. 



41. physiologists are not agreed as to the cause of the 

 motion of blood in the veins.^ The veins have thinner coats 

 than the arteries and are destitute of elasticity. As they are 

 wanting in elasticity, if they had no irritability, they could 

 not act upon the blood contained in them, and accordingly 

 could exert no active force in circulating the blood. But it 

 is found by experiments that the veins are not mere passive 

 tubes ; they possess a certain degree of contractile power, as 

 is shown in the shrinking of the veins on the back of the 

 hands in cold weather ; besides, if a vein be punctured be- 

 tween two ligatures, the blood will spirt out. The veins 

 then assist the circulation by a sli ht degree of contractile 

 power) 



42. Again : when the heart dilates, the blood is sucked 

 up in the veins precisely as it is in a pump. This is denied 

 by some, who KW. thai if the end of a syringe be placed in a 



