The Action of Ancesthetics on Living Tissues. 273 



(2) The effect of a previous section (110) is to produce a somewhat larger 

 rise. 



(3) CHC1 3 to the proximal end produces a fall in potential (107, 108, 109). 

 When there is no previous section (109) the experiment is obviously identical 

 with Experiment 111 ; when there is a previous section, the total effect is less. 

 In other words, if 



x = effect of section, and 



y = effect of CHCI3 in the first part of each experiment, 



Exps. 109 and 111 = y, 

 „ 107 „ lQS = x-y, 

 „ 110 = x + y. 



These results are discussed subsequently in connection with the question 

 as to whether x and y are due to the same mechanism in the nerve or not. 

 Later experiments (Series V and VI) point to an affirmative answer ; as 

 regards this present series, it appears that y is of the same order of magnitude 

 as x, whether CHCI3 or ether is used, and that y has the same direction of 

 current as x. 



A few experiments were made with alcohol vapour; this causes an effect of 

 the same character as CHCI3 and ether, but as it also causes an enormous 

 increase in the resistance of the tissue, due to drying, the experiments were 

 not proceeded with further. 



When, in the second part of each experiment, the anaesthetic is applied to 

 the other part of the nerve, the final result is similar to that of Series I, 

 where the whole nerve is at once anaesthetised. As can be seen, there is 

 a small residual E.M.F., occasionally (in other experiments not quoted here) ; 

 this may reach a value of - 005 to - 006 volt, the exact significance of this 

 is still uncertain. 



Series IV. 



In this series, CHCI3 and ether vapours of different strength were applied 

 simultaneously to both sides of the nerve. The result could have been pre- 

 dicted from an examination of Series I and II, but is a useful control, as 

 certain sources of error are eliminated. 



Experiment. 



Central End. 



Peripheral End. 



E.M.F. initial. 



E.M.F. final. 







per cent. 



per cent. 







931 



51 -0 (ether) 



16 -1 (CHCI3) 



+ 33 



- 1 



932 



16 -1 (CHCu) 





- 8 



-233 



933 



12 -5 (CHCI3) 



16 5 (CHClj) 



+ 13 



- 18 



934 { I 



8 -0 (CHCI3) 

 14 -5 (CHCI3) 



1 14 -5 (CHC1 3 ) 



-16 



-184 (a) 

 - 16 (J) 



113 



54-32 -5 (ether) 



12 -3 (CHCI3) 



-25 



— 7 



