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of the body, than in parts of which the temperature is very much 

 lowered. I have experimented on almost completely amputated 

 limbs of Guinea-pigs, as in the preceding instances. The limbs were 

 placed in a vessel dipped into water at different temperatures. The 

 results have been as follows : 



1st. Water at 104 Fahr. Duration of sensibility, in average 

 forty-one minutes. 



2nd. Water at 80 Fahr. Duration of sensibility forty-nine mi- 

 nutes. 



3rd. Water at 50 Fahr. Duration of sensibility fifty-three mi- 

 nutes. 



4th. Water at 35 Fahr. Duration of sensibility fifty-eight mi- 

 nutes. 



These results, which will not surprise persons who know the laws 

 of the influence of heat and cold on the vital properties of the spinal 

 cord, of motor nerves and muscles, clearly show that the lower 

 the temperature, the longer sensibility persists in parts deprived of 

 circulation. 



The third question I have tried to solve, is whether an augmentation 

 in the vital properties of the spinal cord is able to influence the 

 duration of sensibility in a limb deprived of the circulation of blood. 

 It is known that when a transverse section is made upon the poste- 

 rior surface of the spinal cord in a mammal, and especially in a 

 rabbit, all the parts of the body which are behind the section 

 become much more sensitive than they were previous to the opera- 

 tion. I have made two series of experiments to find out if, in cases 

 of this kind, the duration of sensibility in parts deprived of circulation 

 would be increased. 



In one series of experiments I first divide the posterior columns of 

 the spinal cord and then amputate all the parts of a hind limb ex- 

 cept the nerves, while in another series I divide the spinal cord after 

 having made the amputation. In both series I find that sensibility 

 lasts notably longer than in animals in which the posterior columns 

 have not been divided. For instance, in rabbits, instead of twenty 

 or twenty-two minutes, sensibility lasts thirty or thirty-five minutes ; 

 and in one case I have seen it still persisting, though very weak, 

 after thirty-eight minutes ; I did not in this instance ascertain how 

 long it lasted. 



