PHYSICAL AND LITERARY. 295 



heart beating very regularly and pretty 

 ftrbngly, 21 times in the minute, I immerfed 

 it again in the folution, which had now im- 

 mediate accefs to the heart. After five mi- 

 nutes, I took it out of the folution j and 

 finding the heart without motion, I pricked 

 it with the point of a knife ; upon which it 

 began to beat at the rate of 14 times in the 

 minute, and .continued its motions very 

 languidly, and not without fome interruption, 

 for about a quarter of an hour. 



14. I cut out the heart of a frog, and put 

 it in fountain-water at ten minutes paft tenf^ 

 immediately after immerfion, it beat about 

 28 times in the mijiute. Eighteen minutes 

 paft ten, it made 6 pulfations .in thirty fe- 

 conds. Twenty minutes after ten, T took it 

 out of the water and laid it on a table, and 

 pbferved, that as often as it was gently 

 touched with any thing, it made one full 

 and ftrong contraction, and no more : 

 however, in four or five minutes, it be- 

 gan to beat of its own accord, and, at 

 twenty eight minutes after ten, performed 

 19 pulfations in a minute. Thirty five mi-? 

 minutes paft ten, it beat 12 times in a mi? 

 nute, 



i^. Twenty 



