It may happen that certain of these electrons are no longer retained in their orbit by the electric attraction of the rest of the atom, and may be projected from it like a small planet or comet which escapes towards the stellar spaces.

The phenomena of the emission of light compels us to think that the corpuscles revolve round the nucleus with extreme velocities, or at the rate of thousands of billions of evolutions per second.

It is easy to conceive from this that, notwithstanding its lightness, an atom thus constituted may possess an enormous energy.[43] [Footnote 43: This view of the case has been made very clear by M.
Gustave le Bon in _L'Evolution de la Matiere_ (Paris, 1906).

See especially pp.

36-52, where the amount of the supposed intra-atomic energy is calculated .-- ED.] Other authors imagine that the energy of the corpuscles is principally due to the extremely rapid rotations of those elements on their own axes.