511 



circulation. No doubt it has been occasionally observed, iu experiments 

 made with the view of ascertaining what effects are due to the ligature 

 of the aorta, that sensibility persists in the nerves of the lower limbs 

 much longer than irritability in the muscles, but no precise determi- 

 nation has been made of the exact duration of sensibility in such cases, 

 except, to a certain extent, in some experiments of my own and those 

 of Stannius. My researches, although giving an indication of the 

 duration of sensibility in the lower limbs, had not been made with 

 the special view of elucidating this question, their object being to 

 decide whether the vital properties of muscles and nerves could be 

 restored after having completely disappeared. The experiments of 

 Stannius were made with the same view as mine. It may therefore 

 be said that the subject of the present paper is almost entirely new, 

 at least as regards warm-blooded animals. 



A ligature round the aorta does not stop circulation completely 

 enough to allow any positive conclusion regarding the duration of 

 sensibility in nerves deprived of circulation of blood. 



Desirous of avoiding the causes of error which exist when the aorta 

 is tied, I have proceeded in the following manner : I apply ligatures 

 on the femoral artery, and after having divided this vessel between 

 the ligatures, I amputate the thigh completely, excepting, however, 

 that I leave the two large nerves of the limb undivided and as little 

 injured as possible. 



In experimenting in this way, I find 



1st. That the duration of sensibility in the toes, in Rabbits, varies 

 between twenty and twenty -three minutes. 



2nd. That, in Guinea-pigs, the duration varies between forty and 

 fifty minutes. I have seen sensibility lasting a little more than an 

 hour in one case. 



3rd. That, in Dogs, the duration of sensibility varies between 

 thirty and thirty-five minutes. 



It is a very remarkable fact that the duration of sensibility varies 

 so much in animals so nearly related to each other as Rabbits and 

 Guinea-pigs. 



The second question I propose to examine relates to the influence 

 of temperature on the duration of sensibility in parts deprived of the 

 circulation of blood. It has been erroneously assumed that vital pro- 

 perties last longer in parts submitted to a temperature similar to that 



VOL. x. 2 N 



