342 ESSAYS ANp OBSERVATIONS 
fill remaiming in them or in the mufcular 
fibres them{felves ? 
THE tying or cutting of a nerve, only 
prevents the derivation of any new influ- 
ence from the brain to the parts to which 
it belongs; but does not immediately 
deftroy the power or influence remaining 
in the nerve itfelf. Opium applied in 
fufficient quantity to the fenfible parts of 
animals, not only quickly puts a ftop to 
the function of the brain and fpinal mar- 
row, and thus produces in the mufcles all 
the effects of a ligature on their nerves, . 
but alfo deftroys the power of every ner- 
vous filament in the body (r), and there- 
fore puts a ftop to the motion of the heart 
in frogs fooner than the deftruction of the 
brain and fpinal marrow. 
(t) THe almoft inftantaneous palfy 
brought on the hinder legs of a dog, by 
injeting a folution of opium into the ca- 
vity of its abdomen (N° 22.), and the ef- 
feéts of the fame folution injected into the 
{tomach and guts of a frog deprived of 
its heart (N° 2.), where no part of the o- 
pium could be conveyed to the mufcles, 
nor 
