By the application of a sufficiently intense electric field a Bohr atom could be rendered unstable. For when the drop in potential across the electronic orbit reaches a value of the order of magnitude of the ionizing potential of the atom (10^9 volts/cm.), the electron, instead of remaining in the neighborhood of the nucleus will fall down the hill of potential energy, and the atom will be dissociated. This dissociation is explosive in character. For there is a critical field strength, below which the atom remains stable indefinitely and above which it dissociates in a time of the order of the orbital periods of the atom. The characteristic for the autoelectric current should accordingly show abrupt discontinuities
