1869.] Dr. C. B. RadclifiVs Researches in Animal Electricity. 389 



Step 3. Poles arranged as at first, so as to cause cathelectrotonus in limb 

 A, anelectrotonus in limb B. 



Limb A— +Limb B 



Cathelectrotonus 



after 

 Anelectrotonus 

 on the side of 

 limb A. 



Action of salt, 

 causing in 

 limb A 



Anelectrotonus 



after 

 Cathelectrotonus 

 on the side of 

 limb B. 



Action of salt, 

 causing in 

 limb B 



During. 



Semi-tetanus 

 at first, then rest. 



Luring. 



Rest at first, then 

 twitchings, pro- 

 gressively in- 

 creasing in fre- 

 quency andforce. 



After. 



0. 



After. 



Tetanus. 



Step 4. Poles transposed again, so as to cause anelectrotonus in limb A, 

 cathelectrotonus in limb B. 



Limb A+ —Limb B 



Anelectrotonus 



after 

 Cathelectrotonus 

 on the side of 

 limb A. 



Action of salt, 

 causing in 

 limb A 



Cathelectrotanus 



after 

 Anelectrotonus 

 on the side of 

 limb B. 



Action of salt, 

 causing in 

 limb B 



During. 



Rest at first, 

 then twitchings, 

 progressively in- 

 creasing in fre- 

 quency and force. 



During. 



Semi-tetanus at 

 first, then 

 rest. 



After. 



Semi-tetanus. 



After. 



0. 



In order to explain this experiment, all that is necessary is to realize the 

 fact (for fact it is) that anelectrotonus has to do with a charge from the 

 positive pole, and cathelectrotonus with a charge from the negative pole, 

 and to suppose that these charges react with the natural charge of the 

 animal tissues precisely as they do in the case of the limbs in which inverse 

 and direct currents are passing — in similar cases, that is to say ; for, as 

 regards the phenomena of tension, the state in anelectrotonus is identical 

 with that which is present in the limb in which the current is inverse (see 

 fig. 4), and in cathelectrotonus with that which is present in the limb in 

 which the current is direct (see fig. 3). 



VOL. XVII. 2 G 



