26 MOTION OF THE 



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 consequence 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 ar- 

 teries is nothing more than the impulse or shock of the blood 

 in these vessels. 



CHAPTER IV. 



OF THE MOTION OF THE HEART AND ITS AURICLES, AS SEEN IN 

 THE BODIES OF LIVING ANIMALS. 



BESIDES the motions already spoken of, we have still to con- 

 sider those that appertain to the auricles. 



Caspar Bauhin and John Riolan, 1 most learned men and 

 skilful anatomists, inform us from their observations, that if 

 we carefully watch the movements of the heart in the vivisec- 

 tion of an animal, we shall perceive four motions distinct in 

 time and in place, two of which are proper to the auricles, two 

 to the ventricles. With all deference to such authority I say, 

 that there are four motions distinct in point of place, but not 

 of time; for the two auricles move together, and so also do the 

 two ventricles, in such wise that though the places be four, the 

 times are only two. And this occurs in the following manner: 



There are, as it were, two motions going on together ; one 

 of the auricles, another of the ventricles; these by no means 

 taking place simultaneously, but the motion of the auricles 

 preceding, that of the heart itself following ; the motion appear- 

 ing to begin from the auricles and to extend to the ventricles. 

 When all things are becoming languid, and the heart is dying, 

 as also in fishes and the colder blooded animals, there is a 

 short pause between these two motions, so that the heart aroused, 

 as it were, appears to respond to the motion, now more quickly, 



' Bauhin, lib. ii, cap. 21. Riolan, lib. viii, cap. 1. 



