The Conception and Demonstration of Electron Waves

DEMONSTRATION OF ELECTRON WAVES 547 unbalanced in one direction or the other by one or more electronic units. Yet this remained largely a speculation until the study of the conductivity imparted to gases by X-rays made all other views untenable. Ions of both signs are formed at a uniform rate within the body of a gas subjected to this then newly discovered radiation; their charges are ionic; they move through the gas by diffusion and under the influence of an impressed electric field; they disappear through recombination. Other ideas now familiar were not entirely novel even in 1890; for instance, the idea t h a t positive and negative electrons possess mass as well as charge--that those of one sign are more massive than the other--that within the atom the lighter revolve about the heavier ones. Weber, following on Ampere, had pictured a mechanism of this kind to explain the magnetic properties of materials. All these notions became much more plausible, however, when Lorentz showed (as he did in 1897) that the splitting and polarization of spectral lines by a magnetic field might be explained as the effect of the field upon the period of revolving particles such as Weber had assumed, and t h a t from the magnitude of this so-called "Zeeman effect" one might actually calculate the ratio of the charge of the particle to its mass. The value so found was greater by a factor 2000, or thereabouts, than the similar ratio for hydrogen ions in electrolysis. If the charge of the particle were indeed the electronic charge, then the mass of the particle was about 1/2000 only of the mass of the hydrogen atom--a highly acceptable conclusion.