198 STUDIES IN ELECTRO-PHYSIOLOGY: 



be subject only to Ohm's law, and the tension to the laws 

 we have been discussing. If at any point it was desired 

 to alter the sign again or to alter the tension, the insertion of 

 another condenser-ganglion cell of the required plate-area 

 in circuit would do it. 



The diagrams on next page, Figs. 106, 107, illustrating 

 the neurons of the motor path (after Halliburton), and 

 a similar electrical arrangement, will further explain my 

 meaning. 



Study of the physiological diagram will show that, 

 conforming as the body must do in its structure to estab- 

 lished electrical laws, the source of energy, i.e., the cell of 

 the cerebral grey matter, is to earth (in this case air) in 

 the same manner as the battery in the electrical diagram, 

 while every muscular fibre is to earth (air) through the 

 skin. If it is desired to make a large low-tension motor- 

 cell multipolar, and to transform the tension therefrom 

 upwards, it is only necessary to provide it with one, or 

 more, additional arborisation, linking by induction with 

 one or more condensers of the type of b. 



Judging by their effects, we might believe that quantity 

 and tension constitute two very different elements. They 

 are in reality but two forms of the same thing. The 

 transformation of quantity into tension results simply 

 from the mode of distribution of the same energy. We 

 realise the transformation by concentrating the energy 

 within a very small space, which amounts to raising its 

 level above that of the zero of energy. The converse 

 operation will transform, on the contrary, tension into 

 quantity. A coulomb spread over a sphere of 10,000 

 kilometres radius will give only a pressure of one volt. 

 Let us spread the same quantity of electricity over a sphere 

 of a diameter 100,000 times less that is to say, of 100 

 metres and this same quantity of electricity will produce 

 a potential a hundred thousand times higher that is to 



