t»HYSICAL AND LITERARY. 289 



as the heart. Thirteen minutes before ten, 

 i. e. thirty thne minutes after the frog was 

 taken out of the folution, the auricle fhew- 

 ed, at confiderable intervals, a very fairit 

 pulfation, but the heart lay without any mo- 

 tion. 



9. The fame day, after cutting off the 

 head and deftroying the fpinal marrow of an- 

 other frog, I laid bare its abdominal mufcles 

 and thorax j and, at eighteen minutes pad 

 ten, immerfed it in a folution of opiums as 

 above. Eighteen minutes paft eleven, I took 

 it out of the folution and opened its thorax 

 and pericardium, after which the heart began 

 to move at the rate of 8 times in a minute. 

 Twenty five minutes paft eleven, the heart 

 beat 1 5 times in a minute ; and at twelve 

 o'clock it performed between 13 and 14 vi- 

 brations in the fame time. At two o'clock, 

 [viz. two hours andjorty two minutes after the 

 frog was taken out of the folution) the au- 

 ricle, which was now filled with air, con- 

 tinued to vibrate weakly, about 1 1 times in 

 the minute j but the heart itfelf was without 

 Motion. At ten minutes before four in the 

 afternoon, the auricle ftill continued to 



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Vol. II. O o move, 



