Duration of molecules in upper quantum states

In an article which has been presented to the Physical Review for publication the author has shown the possibility of calculating from data on the intensity of absorption lines the mean life τ of atoms and molecules in excited quantum states, and the specific rate A21 at which they spontaneously leave the excited state 2 to return to the lower state 1. The calculations are based on Fuchtbauer's (1) method of determining the probability that molecules will be activated by the absorption of a quantum of light, combined with Einstein's(2) views as to the mechanism of light absorption and emission.