300 ESSAYS AND OBSERVATIONS 



the opium on the nerves to which it was 

 primarily applied, and to the fympathy 

 of the other nerves with thefe ; and a 

 great deal too little to its abforption and 

 mixture with the blooJ. And it muft be 

 confefTed, that appearances might indeed 

 very readily miflead one here. 



For. after deftroying the brain and 

 fpinal marrow of a frog, the Doclor ob- 

 ferved the heart to continue to beat for 

 feveral hours, and the fiequency of its 

 ftrokes to decreafe but very gradually. 

 " Yet, " fays he *," after decollation and 

 " the deftrucfiion of the brain and fpinal 

 " marrow, opium operates much more 

 " flowly in frogs, than it does when the 

 *' animals are intire : And hence it fol- 

 " lows, that it muft produce its efFecinis 

 " chiefly, if not wholly, by its adion on 

 *' the brain, fpinal marrow, and nervous 

 "fyftem." 



From which he appears to take for 

 granted, that the abforption and circula- 

 tion are no more influenced, by the de- 



flruction 



* Dr Whytt, in Effays Phyfical and Literary, vol, 2. 

 P 302. 



