‎"EPSTEIN, PAUL.‎
‎Zur Theorie des Starkeffektes. - [FIRST EQUATION ON THE STARK EFFECT IN HYDROGEN]‎

‎Leipzig, Ambrosius, 1916. 8vo. In full black cloth with gilt lettering to spine. In ""Annalen der Physik"", Fourth series, No. 50, 1916. Entire issue offered. Library labels pasted on to front end-papers and stamps to title page, otherwise fine. Pp. 489-520. [Entire volume: VIII, 972 pp + 5 folded plates].‎

Reference : 50922

‎First printing of Epstein's seminal paper in which he was able to derive equations for the linear and quadratic Stark effect in hydrogen.""In his classic paper on the theory of the Stark effect [The present], the splitting of the spectral lines in a hydrogen atom by a strong electric field, he worked out the quantization rules in an invariant form and then used them to calculate the splitting of the hydrogen lines. The splitting effect, first observed by Johannes Stark in 1913, could not be explained along classical lines. Showing that Niels Bohr's Quantum description of the hydrogen atom could solve the problem made Epstein's reputation as a theoretical physicist. The match between his theoretical predictions and Stark's data furnished striking support for the RutherfordBohr atomic theory.Working independently, the German astronomer Karl Schwarzschild publicly announced the solution to the same problem one day after Epstein's paper appeared. (As Epstein relates it, Schwarzchild initially had the wrong formula. He corrected it after seeing an announcement of the development of Epstein's result.) Epstein's other contributions to the development of the quantum theory of atomic structure between 1916 and 1921 ranged from his extension of Bohr's theory to nonperiodic motions, including beta decay and the photoelectric effect, to the interference of spectral lines."" (DSB).‎