180 Dr. J. A. Fleming [May 30, 



or by ultra-violet light and from the magnetic deflection of kathode 

 rays, that in all cases where we have to deal with free moving, or 

 vibrating electrons, the electric charge they carry is the same as that 

 conveyed by a hydrogen atom in electrolysis. 



There is good ground for the view that when a gas is made incan- 

 descent, either by an electric discharge or in any other way, the 

 vibrating bodies which give rise to the light waves are these electrons 

 in association with the atom. The energy of mass movement of the 

 atom determines temperature, but the fact that we may have light given 

 out without heat, in short, cold light, becomes at once possible if it is 

 the vibrating electric particle attached to the atom which is the cause 

 'of eye-affecting radiation or light. 



Lorentz, Helmholtz, Thomson and others have shown that such a 

 conception of atomic structure enables us to explain many electro- 

 optic phenomena which are inexplicable on any other theory. Max- 

 well's theory that electric and magnetic effects are due to strains and 

 stresses in the aether, rendered an intelligible account of electric 

 phenomena, so to say, in empty space, and its verification by Hertz 

 placed on a firm basis the theory that the agencies we call electric 

 and magnetic force are affections of the aether. But the complica- 

 tions introduced by the presence of matter in the electric and 

 magnetic fields presented immense difficulties which Maxwell's 

 theory was not able to overcome. 



The electronic theory of electricity, which is an expansion of an 

 idea originally due to Weber, does not invalidate the ideas which lie 

 at the base of Maxwell's theory, but it supplements them by a new 

 conception, viz., that of the electron or electric particle as the thing 

 which is moved by electric force and which in turn gives rise to 

 magnetic force as it moves. The conception of the electron as a 

 point or small region towards which lines of strain in the aether 

 converge, necessitates the correlative motion of positive and negative 

 electrons. We are then led to ask whether the atom is not merely a 

 collocation of electrons. If so, all mechanical and material effects 

 must be translated into the language of electricity. We ought not 

 to seek to create mechanical explanations of electrical phenomena 

 but rather electrical ones of mechanical effects. The inertia of matter 

 is simply due to the inductance of the electron, and ultimately to the 

 time element which is involved in the creation of aether strain in 

 a new place. All the facts of electricity and magnetism are capable 

 of being re-stated in terms of the electron idea. All chemical 

 changes are due to the electric forces brought into existence between 

 atoms which have gained or lose electrons. If moving electrons 

 constitute an electric current, then electrons in rotation are the 

 cause of magnetic effects. In optics it is capable of giving a con- 

 sistent explanation of dispersion, absorption and anomalous dispersion 

 and the relation of the index of refraction to the dielectric constant. 

 A scientific hypothesis, with this wide embrace, which opens many 

 closed doors and enables us to trace out the hidden connection 



