232 EXPERIMENTS relating to 



ftocking-wire, and after laying one end of it upon the half- 

 crown piece which fupported the leg, we with the other end of 

 the wire preflfed the doubled tinfoil againft the half-crown piece 

 which fupported the loins, and found, that inftantly convulfions 

 were produced in the mufcles of the thigh and leg. 



When the tinfoil was paffed around both fciatic nerves, 

 both legs were convulfed, although the half crown piece was 

 placed under one of the legs only. Thefe experiments were 

 tried more than an hour after the fpinal marrow had been cut 

 acrofs. with the fame fuccefs. 



In another frog, in which the fpinal marrow was not divided, 

 we found the fame means produce the fame effects upon the 

 legs, but did not obferve, that the mufcles above the tinfoil 

 in the trunk or fore-legs were affected. 



When the touches were quickly repeated, the motions feem- 

 ed to become, by degrees, lefs vigorous, but did not ceafe af- 

 ter repeating them often, even where the fpinal marrow had 

 been divided tranfverfely. 



On the 10th of November, I profecuted the fubject farther 

 by the following experiments : 



Experiment I. 



After cutting off the hind legs of a living frog, I laid bare 

 the upper part of its fpinal marrow and furrounded it with tin- 

 foil ; and in another frog, after laying bare the brain, I thruft 

 into it a bit of tinfoil. 1 then placed one half crown piece be- 

 tween the table and the body of the frog, oppofite to the tin- 

 foil, and another half crown piece between the table and the 

 lower part of the trunk of the animal, and, on applying tne 

 wire, as before, I found convulfions produced in the fore-legs 

 and body. Gold had nearly the fame effect as ulver ; but the 



3 convulfions 



