404 EFFECT OF IRRITATION OF A POLARIZED NERVE. 



EXPERIMENT 188. 



In experiment 188, with a descending irri^ting current of 2 DaniBl 

 cells, " rheocliord 1413," an ascending polarizing current, Daniel, 

 "rheochord 53" usually produced a decreased excitability of the nerve. 

 With a descending polarizing current of the same strength the opposite 

 eflect was obtained. Increasing this current to " rheochord 57," it failed 

 to influence the eflect of the irritation. A polarizing current of 1 Daniel, 

 "rheochord G," passing in either direction, increased the excitability of 

 the nerve. With an irritating current derived from 1 Daniel, " rheochord 

 1109," an ascending polarizing current from 1 Daniel, "rheochord 10," 

 still slightly increased the excitability. When with the same strength 

 of currents the ijolarization was descending, this latter always abolished 

 the effect of the irritation. The latter effect always occurred when the 

 polarizing current was increased to 2 or 3 Daniels. When but 1 Daniel 

 was used for the descending j)olarization, this produced increased excit- 

 ability of the nerve. 



