PHYSICALann LITERARY. 441 
much longer before it operates, than when it 
is fwallowed in the morning. If the heart, 
therefore, like the other organs of the body, 
becomes lefs fenfible or irritable in time of 
fleep, it will not be fo quickly excited into 
contraction as ufual, by the venous blood rufh- 
ing into its cavities; and hence its contracti- 
ons will not only be more flowly repeated, 
but the pulfe will be full, becaufe the ventri- _ 
‘cles do not contraa till they are much dif- 
tended with blood. This will {till further 
appear, if we confider how remarkably flow 
and full the pulfe is, in an apoplexy, where 
the fenfibility of all the parts and their apti- 
tude for motion, are much more impaired 
than in common fleep, and how opium, which 
occafions fleep, and leffens the fenfe of feel- 
_ ing every where thro’ the body, when given 
in a large dofe, renders the pulfe uncom- 
monly flow and full. Thus the heart of a 
frog, into whofe ftomach and guts J had, an 
hour before, injected a folution of opium, 
was obferved to beat near four times flower 
than ufual; and the auricle and great veins 
leading to the heart, were remarkably dif- 
tended with blood, as was alfo the ventricle 
of the heart before every contra€tion. At 
Kkk the 
