Z 
PHYSICAL ano LITERARY. 315 
7, AFTER cutting off a frog’s head and 
k 
deftroying its {pinal marrow with a red 
hot wire, I laid bare the abdominal muf- 
cles and thorax, as in the laft experiment, 
and immerfed the whole body of the frog 
in a turbid folution of opium, at half an 
hour paft nine in the morning. ‘Thirty 
fix minutes after immerfion I took it out 
of the folution, and opened its thorax and 
pericardium, ‘The heart and its auricle 
beat, each, twenty fix times in a minute, _ 
andthe pulfations of the auricle preceeded 
; 
 thofe of the heart regularly. The heart 
did not appear to be more {welled or red- 
4 der than in a natural ftate, and the auri- 
cle was not near fo full of blood as in 
Exp. 6. Twelve minutes paft ten, viz. 
fix minutes after this frog was taken out 
of the folution of opium, its heart beat 
27 times ina minute. At eleven o clock 
it performed 18 vibrations in that time ; 
and 16 at a quarter before twelve. At 
two o'clock afternoon, the auricle, which 
t __ having expelled all its blood, was now on- , 
| ly filled with air, continued its motions; 
but the heart lay at reft. Ten minutes 
: pat 
