30 Motion of the Heart and Blood 



animals palpitates within their veins, (meaning the 

 arteries,) and by the pulse is sent everywhere simul- 

 taneously." And further, 1 "thus do all the veins 

 pulsate together and by successive strokes, because 

 they all depend upon the heart ; and, as it is always in 

 motion, so are they likewise always moving together, 

 but by successive movements." It is well to observe 

 with Galen, in this place, that the old philosophers 

 called the arteries veins. 



I happened upon one occasion to have a particular 

 case under my care, which plainly satisfied me of this 

 truth : A certain person was affected with a large 

 pulsating tumour on the right side of the neck, called 

 an aneurism, just at that part where the artery descends 

 into the axilla, produced by an erosion of the artery 

 itself, and daily increasing in size; this tumour was 

 visibly distended as it received the charge of blood 

 brought to it by the artery, with each stroke of the 

 heart : the connexion of parts was obvious when the 

 body of the patient came to be opened after his death. 

 The pulse in the corresponding arm was small, in con- 

 sequence of the greater portion of the blood being 

 diverted into the tumour and so intercepted. 



Whence it appears that wherever the motion of the 

 blood through the arteries is impeded, whether it be by 

 compression or infarction, or interception, there do the 

 remote divisions of the arteries beat less forcibly, seeing 

 that the pulse of the arteries is nothing more than the 

 impulse or shock of the blood in these vessels. 



1 De Respirat. cap. 20. 



