166 NERVE FORCE NOT ELECTRICITY. 



bearing on the physiological question when we recollect the 

 infinite variety of merely physical phenomena which may be 

 displayed in such a medium as the animal body when subject 

 to electric currents, considering the many new facts discovered 

 in making telegraph cables even. 



We come back to the question by what force, de- 

 veloped in nerve protoplasm and conducted by nerve 

 fibre, tlie whole of muscular work can be done as sup- 

 posed by Beale. If some of the foregoing facts favour 

 the idea that the force is electricity, yet we must re- 

 member that the nerves are not better conductors of 

 electricity than other tissues. " The moist tissues, 

 with the exception of the bones, are all equally good, 

 or, rather, equally bad conductors of electricity about 

 three million times worse than quicksilver " (J. Ranke). 

 Besides, as before said, tbere is no demonstrable insu- 

 lation by the sbeatb of Schwann, so the nerves are not 

 fitted for simple conduction of electric currents; and 

 these have no reason to choose tbe nerves as their 

 channels, so they spread through the moist tissues 

 almost uniformly.* These facts form an insurmount- 



* If the two electrodes of any current apparatus are laid on any 

 two given points of the human body, the electricity from, the positive 

 pole spreads through the body in all directions, to be gathered together 

 again at the negative pole. The whole body must be looked upon, 

 theoretically as filled with current curves. Hence it appears as if it 

 were impossible to submit any isolated spot to the electric influence. 

 In fact, strictly speaking, it is impossible, and the fact cannot be 

 sharply enough insisted upon." Practically, the electrization of iso- 

 lated parts is only effected in a very qualified degree by the greater 

 strength of the current at the spot over that which spreads by diffu- 

 sion (Fick, " Die Mediciriische Physik," p. 370). This, no doubt, be- 

 sides interfering with electro-therapeutics, vitiates many physiological 

 experiments. Dupuy found that in electrifying parts of the brain the 

 stimulus was widely diffused over the hemispheres, and the results did 

 not correspond with those of Dr. Ferrier (" Lancet," 24th January, 

 187J.. 



