OS OPlUMc 357; 



superior part of the body, except by the undivided ischiatic Effects of 



,., . rr> , 1 \ t • J • X opium on thfe 



nerves, were likewise aifected by convulsions, ana in two ^^jna systeim 



hours and ten minutes the ajiimal was dead. 



Tlie ligatures which united the divided edges of the skin 

 of the thighs were then separated, and the ischiatic nerves 

 exposed; they were compressed; the compression of the 

 nerve on one side, produced a slight contraction in one 

 of the muscles in the lower part of the limb, but when 

 repeated, no contraction followed ; the compression of the 

 nerve of the other limb, occasioned no contractions. 

 The irritability in all the other muscles was exhausted. 



Into a third frog, prepared in like manner, forty drops 

 were injected: after fifteen minutes the animal was con- 

 vulsed ; after the space of two hours it was dead. Com- 

 pression of the nerves did not excite the least motion in any 

 of the muscles beneath, and when the skin was removed, 

 the application of salt was equally as ineflFectual, ncrt the 

 slightest degree of contraction was rendered visible. 



From the event of these last related experiments we arc 

 instructed, that the effect of opium is extended to the most 

 distant parts of the body, althd^igh the only communication 

 which remains between the extreme parts and the body 

 itself, is by the contlnui?^ of nerves, and these palpably 

 not in a state best adapted to convey impressions. 



It yd remained to be examined if by a'tiy other com- 

 munication the etfect of opium could be extended to distant 

 parts, if the supposed integrity and indivisibility of the 

 irrftalble principle was capable of doing it. 



Exp. I5*. The spine of a frog was divided above that 

 part from whence the nerves issue which supply the inferior 

 extremities ; care was taken not to wound any other part. 



After this operation, the muscles of the inferior extre- 

 mities retained their irritability, and though the animal had 

 lost the power of voluntary motion in them, it had strength 

 to drag them after its body. 



Into the stomach of a frog thus prepared, forty drops 

 of the solution were injected; seventeen minutes after, all 

 the patts of the animal above the point of the division of 



* Vide Inaug. Dissert, p. 62. Exp. 4?. 



th©- 



