PHYSICAL AND LITERARY. 325? 



ing to render it not improbable, that thd 

 matter of feme poifonous fubflances 

 reaches higher in the nerves than the 

 part to which they are firft applied, and 

 lodges in them a confiderable time before! 

 it produces its full effects. If a probe 

 which has been dipped in ftrong fpirit of 

 hartfliorn, be applied to the bared trunk 

 of the fciatic nerve of a frog, it feems, 

 as we would have expedled, to give great 

 pain to the animal, and not only ahiioft 

 inftantly deprives all the limb, behind this 

 part, of fenfe and motion ; but the animal, 

 in fix experiments I made, died two days 

 thereafter, though I put it immediately 

 into water ; and tho', feveral hours after the 

 experiment was made, it exerted the fore 

 part of its body with its former vigour ; 

 nay, even in the weak leg, the circulation 

 of the blood continued with great rapi* 

 dity. Yet, in a great number of other 

 frogs, cutting the fciatic nerves acrofs 

 was fo far from killing, that they not on- 

 ly all furvived the operations, but, in Se- 

 veral of them, the divided parts of thef 

 Vol. in. • T t nervs 



