Il8 ANIMAL ELECTRICITY. LECTURE V. 



may Indeed for the moment Imagine that the scale 

 is an enormous nerve) we have : — 



1. The make-current to the rioht + — ^ — 



2. Its counter-current to the left ^ — 



3. The break-current to the left - <-€ + 



4. Its counter-current to the right — ^ 



5. V. Fleischl's current to the left ^ — 



i.e., as an after-anodic action-current of current No. 3, 

 which alone is exciting, and which gives rise to 

 " zincativity " on the side where the arrow-tail has 

 been figured. But for this arrow-tail representing a 

 post-anodic zincativity the four currents i, 2, 3, 4 

 would neutralise each other, or if any difference 

 occurred it should be to the right by reason of an 

 excess of 4 over 2. 



I am sorry to dwell so long upon this apparently 

 small and dubious point, still let me state in a few 

 sentences the reasoning that brought me up against 

 it. Considerino- that make excitation is kathodic 

 (p. 78), that excited tissue is zincative (p. 84), that 

 the make and break induced currents being equal 

 in quantity and unequal in potential, will therefore 

 be unequally excitant, while neutralising each other 

 on the galvanometer, I argued that with the nerve 

 and galvanometer In one circuit, it might be possible 

 to obtain a deflection in the direction of the make 

 owing to an action-current opposed to the break. 

 In the event I obtained just the opposite effect, 

 and reproduced what I recognised to be the effect 



