PHYSICAL ano LIT ERARY. 319 
‘to return ; at fix minutes paft twelve, (7. ¢. 
an hour and nine minutes after the frog 
was taken out of the folution) its heart 
made only 6 pulfations in the minute ; 
and, at eleven minutes paft twelve, obfer- 
ving it without motion, I pricked it with 
-a pin, and breathed upon it. in order to 
fenew its pulfation, but to no purpofe. 
ii. TwinTy eight minutes paft feyen 
in the evening, I laid open the whole aé- 
domen and thorax of a frog, and immedi- 
ately after immerfed it ina folution of opi- 
um as above. Thirty eight minutes patft 
feven, when I pricked its legs with the 
point of a penknife, it made very little 
motion. ‘Two minutes after this, I turn- 
ed it to its back, and obferved its heart 
moving only between ten and eleven times 
in a minute, Having laid the frog again 
on its belly, that it might be more expo- 
fed to the action of the opium ;. at forty 
eight minutes paft feven, i. ¢. twenty mi- 
nutes from the firft immerficn, I turned 
it again to its back, and obferving the 
heart without motion, I opened the peri- 
 bardium; which producing no effeé, 1 
cut 
