FHYSICAL AND LITERARY. 285 



ftd twelve times in a minute ; but the heart 

 itfelf lay without motion, was fwelled and 

 very red : however, when pricked with a 

 pin, it performed two or three pulfations, 

 and then remained at reft, till roufed by a 

 T\cvt Jiimidus. At thirty five minutes paft 

 five, the heart feemed to be quite dead, but 

 the auricle continued its motion j nay, at 

 half an hour paft eight, near three hours 

 after the heart had been without motion, the 

 auricle, which was very near as much filled 

 with blood as when I firft opened this frog, 

 beat II or 12 times in the minute ^ its pul- 

 fations, however, were not now fo regular 

 ^s to time, as they had been before. 



Is it not probable, that the auricle of this 

 frog's heart beat longer than ufual, becaufe 

 it continued, to the laft, to be filled with 

 blood J whereas, generally, the auricles of 

 frogs hearts, which are opened after decol- 

 lation and the deftrudion of their fpinal mar- 

 row, expell, after fome time, the blood 

 which they contain, and acquire the ap- 

 pearance of a fmall pellucid bladder filled 

 with air ? 



6. I laid bare the abdominal mufcles and 

 tbora:?c of a frog, by difTedting oiF the fkin, 



^n4 



