494 



COMPARATIVE ELECTRO-PHYSIOLOGY 



responses as usual, a I per cent, solution of alcohol was 

 applied at the proximal contact. It will be seen from the 

 record in fig. 304 that the immediate effect was a depression 



FIG. 303. Photographic Record of Effect of Alcohol on Conductivity 

 The three large responses to the left show the normal effect of transmitted 

 excitation. Responses almost abolished, as seen on the right, by 

 depression of conductivity. 



of the amplitude of response. This subsequently becomes 

 converted into a diphasic response, consisting of a preliminary 

 positive followed by the normal negative ; and finally the 





FIG. 304. Photographic Record showing Effect of Alcohol on 

 Responsivity 



a, normal responses, depressed, after application of alcohol, to d ; and 

 converted later to abnormal positive responses c. 



response was totally reversed to positive, by the abolition of 

 the true excitatory effect. 



It is thus seen that while dilute alcohol exalts the recep- 

 tive excitability, it induces a depression of both conductivity 



