ABSTRACT
The atomic theory is no longer merely a hypothesis introduced to explain the laws of chemical combination; we are able to detect and count the individual atoms. It can determine the actual mass of an atom in various ways, and know its value with considerable accuracy. The idea that the atom is an electrical structure received a great impetus by the detection of the electron by J. J. Thomson; and, moreover, the Zeeman effect showed that all atoms must contain electrons. The atomic character of negative electricity is well established; it always find the negative electron, however produced, carrying a definite charge. Two powerful methods that aid us in determining the inner structure of the atom the scattering of high-speed particles in transit through matter, and the vibrations of the interior parts of the atom. In C. T. R. Wilson's photographs of the tracks of the particles through a gas we notice many sudden bends in the paths.
