312 ESSAYS any OBSERVATIONS 
‘where it o expofed to a cool breeze; 
upon which the motion of its heart 
became flower, fo that in a fhort time it 
only made 25 pulfes ina minute, I then 
expofed it anew to the fun-beams, by 
which its motion was foon quickened, fo 
that it beat 30 times in a minute. 
AT twenty-five minutes paft five in the 
evening, (viz. fix hours and fixteen mi- 
nutes after decollation and the deftruction — 
of its {pinal marrow) the auricle of this. 
frog’s heart, which was ftill filled with 
blood, contra¢ted twelve times in a mi- 
nute; but the heart itfelf lay without 
motion, was {welled and very red : How- 
ever, when pricked with a pin, it perform- 
ed two or three pulfations, and then re- 
mained at reft, till roufed by a new fi- 
mulus. At thirty five minutes paft five, 
the heart feemed to be quite dead, but the, 
auricle continued its motion; may, 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 11 or 12 times in the mi- 
nute 5 
