ANIMAL AND VEGETABLE 55 



Now, it is quite clear that if nerve-force, or, as I prefer 

 to call it, neuro-electricity, is constantly generated in the 

 body, it must be as constantly given off, otherwise the neuro- 

 electrical pressure would become excessive. The absolute 

 insulation of the body is provided by the skin, but the skin 

 is not an insulator of very high resistance. Nor is its 

 resistance uniform, any more than the generation of 

 neuro-electricity is uniform in all individuals. Sign, 

 electromotive force, and current vary with the person as much 

 as height, weight, and anthropometric measurements vary. 



If nerve- energy were visible we should probably see 

 every human being one might say every living thing- 

 surrounded by an aura, or neuro- electrical field, extending 

 some distance from the body and gradually fading into space. 



We must, however, realise that the rapidity with which 

 that neuro-electricity can pass to earth must depend upon 

 the manner in which the body is protected or insulated 

 from the earth by dielectrics other than the skin. For 

 example, the insulation of a carpeted room with the win- 

 dows and doors closed would be infinitely higher than if 

 the body were exposed to the open air, or in contact with 

 damp earth, or with the hands touching some metallic 

 substance connecting with the earth. We may, in fact, 

 conceive many conditions in which the insulation of the 

 body could be increased or impaired. 



In considering " air " as the normal " earth " of the 

 body it must not be thought that I am unsupported in the 

 view I have taken, although physicists may not, so far, 

 have fully appreciated the conductivity of air, under 

 varying conditions of humidity and movement, in its 

 relation to that form of energy called nerve-force, or even 

 to electricity of so low a tension as 4 or 5 millivolts. 



In his Physiological Physics M'Gregor-Robertson, who 

 will be remembered in connection with the University of 

 Glasgow, says : " A charged body in a current of air slowly 



