Leipzig: Johann Ambrosius Barth, 1923. First edition of this sequel to Bohr’s famous ‘Quantum theory of line spectra’, Bohr’s final attempt to understand complex atomic spectra using the old quantum theory. Birge played a pivotal role in the introduction on quantum physics in the United States.
In this article "Bohr discussed in greater detail than ever before the problem of the complex structure of spectral linesand the anomalous Zeeman effects. He argued there in connection with the case of doublet spectra that 'we must be prepared for the possibility that the coupling between the series electron and the atomic corecannot be described directly after the model of the quantization rule for persiodicity syatems' and that the analysis of the emperical data forced one to assume that 'the orientation of the orbit of the series electron relative to the atomic core cannot be described either by interger values of j'. ... Although Bohr, in his article, did not hide 'the incompleteness of the theoretical foundations' of the available atomic theory, he remained hopeful that 'desperate' steps could be avoided." (Mehra & Rechenberg: Historical Development of Quantum Theory, Vol. I, p.493). This offprint is from the library of Raymond Thayer Birge (1887-1980): "Birge was a pivotal figure in introducing modern quantum physics in the United States and an architect of one of the most prestigious departments of physics. ... Influenced by some early experiments of Robert W. Wood, which he followed up in his dissertation work under Mendenhall, Birge early became adept in the techniques of molecular spectroscopy and a "missionary for the Bohr atom," as he styled himself . ... Birge's advocacy of the Bohr theory and his work in molecular spectroscopy attracted the attention of the National Research Council, which nominated him to the Committee on Radiation in Gases . This committee prepared the report "Molecular Spectra in Gases" between 1922 and 1926, a crucial time in the evolution of the quantum theory . Birge's contribution to the report, on electronic bands, was the most extensive chapter . Synthesizing data from his dissertation research, from astrophysical studies at the Mount Wilson Observatory, and from his own research group at the University of California, Birge reinterpreted them in light of the Bohr theory ." (Dictionary of Scientific Biography).
Offprint from: Annalen der Physik, Vol. 71, pp. 228-288. 8vo. Original printed wrappers, a bit creased, worn at spine - in all very good. Provenance: from the library of Raymond T. Birge (1887-1980), with his signature and notes on the front cover and extensive scientific annotations throghout the text.