CHAPTER II 



OF THE MOTIONS OF THE HEART, AS SEEN IN THE 

 DISSECTION OF LIVING ANIMALS 



IN the first place, then, when the chest of a living 

 animal is laid open and the capsule that immediately 

 surrounds the heart is slit up or removed, the organ is 

 seen now to move, now to be at rest ; there is a time 

 when it moves, and a time when it is motionless. 



These things are more obvious in the colder animals, 

 such as toads, frogs, serpents, small fishes, crabs, 

 shrimps, snails, and shell-fish. They also become more 

 distinct in warm-blooded animals, such as the dog and 

 hog, if they be attentively noted when the heart begins 

 to flag, to move more slowly, and, as it were, to die : 

 the movements then become slower and rarer, the 

 pauses longer, by which it is made much more easy to 

 perceive and unravel what the motions really are, and 

 how they are performed. In the pause, as in death, 

 the heart is soft, flaccid, exhausted, lying, as it were, 

 at rest. 



In the motion, and interval in which this is accom- 

 plished, three principal circumstances are to be noted : 



1. That the heart is erected, and rises upwards to a 

 point, so that at this time it strikes against the breast 

 and the pulse is felt externally. 



2. That it is everywhere contracted, but more 

 especially towards the sides, so that it looks narrower, 

 relatively longer, more drawn together. The heart of 

 an eel taken out of the body of the animal and placed 

 upon the table or the hand, shows these particulars ; 



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