Recent Theories of Electricity. 207 



This unit of matter must be reduced in size as refinement of 

 observation increases so that we may always be able to discuss 

 it mathematically in the aggregate only. 



At the present time this protion is the electron, and the 

 only attributes necessary to assign to it are inertia in the 

 Newtonian sense, a force of gravitational attraction and a 

 force of electrical attraction, either positive or negative in 

 sign. No causes for these attributes can be given as they 

 are fundamental. If the experiments of Kaut'mann, which 

 show that an electrified particle in motion has an apparently 

 increased momentum, are cited as supporting the view that 

 inertia is a function of velocity and should be considered as 

 an attribute of an invariable quantity, the electrical charge, 

 I hope to show that it is possible to accept Kaufmann's 

 results and at the same time the invariability of inertia. 



Before proceeding further with this discussion it is con- 

 venient to assemble the foregoing ideas in a concise form. 



1. The fundamental quantitative units are length, mass, 

 and time. The«e are continuous functions, or at least 

 indefinitely divisible. 



2. Matter has an objective reality and its quantity is 

 measured by its mass or inertia. 



3. Mass is an invariable function whose total quantity is 

 conservative. 



4. Energy is a conservative function. 



5. Energy is divided, for convenience, into three types : 

 potential, kinetic, and radiant energy. 



6. Potential energy depends on force and position and is 

 measured by the formula, V = mcj){ (/. (/ — V)}. 



7. Kinetic energy is the energy of a moving bod}': its 

 formula is T = m<fi(v). 



P. Radiant energy is the expression for the fact that heat, 

 light, and electromagnetic energy pass through free space. 

 It is not associated with matter and is conveniently expressed 

 as a function of an "inertia" and a "velocity" factor, 

 R — cj)(m. v). The velocity factor will be taken to be a 

 periodic motion with a translational velocity of o X 10 10 

 centimetres per second. The inertia factor is twice the 

 amount of the energy divided by the velocity squared. 



9. The aether is a name given to a fictitious substance whose 

 inertia is the inertia factor of radiant energy. 



10. The protion, using this name to avoid confusion with 

 the atom of chemical reactions, is the least portion of matter 

 recognized experimentally. It is the scientific unit of mass 

 and can be dealt with mathematically only in aggregates. 

 At the present time this unit is the electron. 



