94 



THE SIGNS OF LIFE 



[LECT. 



integrity of the skin is a necessary condition. With killed skin, 

 both surfaces give only the small counter currents of ordinary 



Eocc 

 Poi. - 



Eocc. f- 

 PoL. - 



SKIN OF FROG. 



Excited and led off by its 

 external surface. 



Excited and led off by its 

 internal surface. 



polarisation. With three external electrodes, and proceeding 

 on the ABC plan, to test the separate unipolar effects at A 

 and at B (p. 69), the antidrome-anodic effect has sometimes 

 exceeded and sometimes fallen short of the homodrome- 

 kathodic effect. The first inequality proves nothing, as it 

 might be an effect of ordinary polarisation ; the second 

 inequality proves, that under certain conditions, and in spite 

 of ordinary polarisation, the kathode is the more effective pole. 



So that, in sum, we may conclude with certainty that both 

 poles are effective, and with less certainty that the kathode 



PA B C A 



//?. 



> E.OCC. 

 i Resp. 



1 



2 



FROG'S' SKIN. 



All responses are outgoing. 

 The homodrome kathodic cur- 

 rents I and 4 exceed the anti- 

 drome anodic currents 2 and $ 



VEGETABLE SKIN. 

 All responses are ingoing. 

 The homodrome anodic currents 

 2 and 3 exceed the antidrome 

 kathodic currents I and 4. 



is more effective than the anode. It is somewhat surprising 



