390 



A VERS. 



[Vol. VIII. 



represent the whole truth, otherwise, upon the stimulation of 

 the separated nerves simultaneously, the muscles would give 

 the same reaction as when the trunk of the sciatic is stimu- 

 lated. 



To return to the explanation Bowditch suggests for the 

 ^^ ether effect^' which may be said to transfer the extensor point 

 of response further up the scale of intensities, and, of course, 

 the flexor point of response follows it. The cause of the 

 transfer is the partial ether paralysis of the nerve substance. 

 An examination of the tables given for the larynx and leg 

 shows that if I substitute the word rate for etJier and partial 

 rate polai'ization for the etJier paralysis of Prof. Bowditch's 

 explanation of the ether effect, these two series of experiments 

 are brought into one catagory. The rate of stimulation, like 

 sulphuric ether, exerts a special influence on nerve substance 

 — in both cases probably of a molecular nature — which 

 reduces the irritability or the capability of the nerve to trans- 

 fer electrical stimuli. It renders the nerve axis cylinder more 

 resistent to molecular change. Further than this my experi- 

 ments do not give any insight into the causes of these phe- 

 nomena. 



The results of all observers on the larynx up to the present 

 time may be tabulated as follows : 



A stimulation of the laryngeal nerve with the Faradic current causes 

 with 



(a) Low Rates and Intensities. 



(fi) High Intensities 

 and Rate.+ 



(c) High Rate and 

 Intensities. ± 



Man 



Dog 

 Cat 



Frog 



opening 



do. 



C only; with reflex stimula- " 



closin"" ^ *^°" °^ ^^ pneumo-gas- 

 ^ \ trie nerve with high R 

 I and I. 



do. 



opening, and some- 

 times closing 



do. 



opening with closure 



do. 



closing 



do. 



openm^ 



do. 



It will be observed that man and the dog agree, and that the 

 cat and the Frog, while differing from them, are in harmony with 



