ANIMAL ELECTRICITY. LECTURE III. 7 I 



of " Bcihnung," that augmented mobility of protoplasm 

 which is a characteristic effect of carbonic acid, the 

 principal product of previous activity, than to say 

 "that excitation arouses a tissue to a state of greater 

 expectancy as well as of greater activit)." 



And in this connection one is tempted to at least 

 ask oneself whether the converse phenomena known to 

 us as "fatigue," the "refractory state," "inhibition," 

 may not also be connected with the evolution of car- 

 bonic acid — whether its anaesthetic action, which is its 

 full effect, may not come into play with exaggerated 

 or with culminating activity. But upon the considera- 

 tion of this negative aspect of nerve activity I do not 

 feel able to enter at present. 



In conclusion, let me briefly answer two questions 

 that have been very frequently put me with regard to 

 these records. I will answer them briefly, and by no 

 means to my own satisfaction, for the answers are 

 little more than counter-questions. 



What interpretation do you place upon these nega- 

 tive and positive effects ? 



What is the meanino- of that remarkable alteration 

 of base-line caused by carbonic acid ? 



As to the first question, 1 ask myself whether the 

 negative and positive effects are to be regarded as 

 signs of opposite chemical movements, whether the 

 neo-ative is to be taken as a sio-n of disintegration and 

 the positive as a sign of integration, in the sense of 

 Hering's dissimilation and assimilation — or whether 



