VIS NERVOSA NOT ELECTRICITY. 129 



" Every attempt to identify it with the electric current as it 

 circulates in a telegraph-wire, must appear hopeless, even if a 

 circuit, such as would be necessary for the supposed nerve 

 current to circulate in, were anatomically demonstrated. Thus 

 to the other arguments against this view of the nervous agent 

 that the resistance of the nerve tubes would be far too great 

 for any battery to send an available current through them 

 that the physiological insulation of the nerve tubes from each 

 other would be impossible to explain that the effect of liga- 

 ture, or of cutting the nerve and causing its ends to meet again, 

 would be equally obscure. What we have termed the nervous 

 agent, if we look upon its very small velocity, in all probability, 

 is some internal motion perhaps even some chemical change 

 of the substance itself contained in the nerve tubes, spreading 

 along the tubes, according to the speaker's experiments, both 

 ways from any point where the equilibrium has been disturbed ; 

 being capable of an almost infinite number of variations or 

 gradations, and of so peculiar a character as to require the 

 unimpaired condition of the nervous structure " (" Matter and 

 Force," B. Jones, p. 130). 



To this Beale rejoins, in substance, that he has 

 discovered the anatomical conditions of a circuit, 

 although he cannot speak with equal confidence of 

 insulation; that the experiments with strong electric 

 currents through nerve-fibres, though undamaged, are 

 unsatisfactory; that the loss of excitability, by death, 

 without loss of conducting power of electricity, may 

 depend on changes as to moisture and of currents of 

 fluid, caused by the death of the protoplasm ; and to 

 the objection of the uncommonly slow velocity of the 

 nerve current compared to that of electricity, he says 

 that it is not yet known how slowly electricity would 

 travel through such a bad conductor as the axis 

 cylinder, and certainly it would go immensely slower 



9 



