18 Prof. S. P. Thompson on the Conservation of Electricity , 



tricity being repelled through a conductor against some 

 existing electromotive force, thereby doing work (as, for 

 example, by being sent through electrolytic cells, where it 

 does electrochemical work against the electromotive force of 

 the cells) ; or (ii) by the charged sphere being itself moved 

 (mechanical forces being supposed absent), the work in this 

 case being the half-product of the quantity of electricity 

 moved into the difference of potentials. In any case the 

 potential energy of the system, as at first supposed, will 

 reappear as energy in the final configuration of the system, 

 whether that energy be transferred from its initial distribu- 

 tion to its final distribution in the system by electrical or 

 mechanical reactions. 



It is well recognized that the kinetic energy of a moving 

 mass may be transformed into other forms of kinetic energy, 

 the value of the transformation depending on the conditions 

 of the transformation. So, also, the potential energy of a 

 system may be transformed into either of the two kinds of 

 kinetic energy and be re-transformed into potential energy by 

 transference through the system under appropriate condi- 

 tions, the force exhibited during the operation being pondero- 

 motive or electromotive according to whether, in the round 

 of changes from the initial to the final state, the energy is 

 applied to the reaction of matter upon matter, or to that of 

 electricity upon electricity. 



6. Relation of Matter, Energy, and Electricity in respect of 

 Distribution in Space. — Suppose all the matter in the universe 

 were to be redistributed with a uniform distribution through- 

 out space. Such a distribution would possess a maximum of 

 potential energy, and would therefore be in the condition of 

 most unstable equilibrium possible. The Newtonian law of 

 self-attraction, varying in intensity with the inverse square 

 of the distance (though it is probably not an ultimate pro- 

 perty of matter), would at once come into play, and cause 

 the system to tend to a condition of aggregation in nuclei, 

 the potential energy turning into kinetic as the separate 

 masses gravitated towards one another. As these masses 

 clashed together, a part at least of their energy being trans- 

 formed into heat, the tendency would set in, as laid down in 

 the theory of the Dissipation of Energy, to produce a 

 uniform distribution of temperature throughout space ; which 

 process would be further aided by the process of radiation, as 

 laid down in the Electric Theory of Radiation below (§ 7) as 

 consisting in a transference of energy through the forms of 

 electrokinetic and electropotential energy, alternately ex- 

 hibited in the vibrations of the interstellar medium, until 

 absorbed by matter to reappear again as heat. 



