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 consider those that appertain to the auricles. 



Casper 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 vivisection 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 fol- 

 lowing manner : 



There are, as it were, two motions going on together r 

 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 fol- 

 lowing ; the motion appearing to begin from the auricles 

 and to extend to the ventricles. When all things are be- 

 coming languid, and the heart is dying, as also in fishes 

 and the colder blooded animals, there is a short pause be- 

 tween these two motions, so that the heart aroused, as it 

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

 now more tardily; and at length, and when near to 



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



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