Some new sum rules for atomic transition probabilities are developed; they are similar to the well-known rule of Kuhn, Reiche, and Thomas. They give, if unpolarized light is incident on any gaseous element in any given discrete energy level, the total absorption, excitation plus ionization, with various types of frequency weighting. The results are similar to those of Dirac and Harding, but are more general in that they apply to any discrete state of any atom, rather than to the ground state of hydrogen only. The method differs from that of Dirac and Harding.

• Received 27 June 1932

DOI:https://doi.org/10.1103/PhysRev.41.432