London: Taylor & Francis, 1913. First editions.
Extremely rare author’s presentation offprints of his great trilogy, which constitutes the birth of modern atomic physics. “Bohr’s three-part paper postulated the existence of stationary states of an atomic system whose behavior could be described using classical mechanics, while the transition of the system from one stationary state to another would represent a non-classical process accompanied by emission or absorption of one quantum of homogeneous radiation, the frequency of which was related to its energy by Planck’s equation” (Norman).
In his previous paper (‘On the Theory of Decrease of Velocity of Moving Electrified Particles on passing through Matter’) Bohr had adopted Rutherford’s nuclear model of the atom, and had become convinced that it was the peripheral electrons that determined the chemical properties of an element, whereas the nucleus determine the radioactive properties. However, Rutherford’s model had an apparent explanatory problem: Why were the negatively charged electrons held away from the positive nucleus? In his doctoral dissertation on the electron theory of metals, Bohr had clarified the limitations of this theory, in particular its ability to explain magnetic properties, and he had shown how this arose from the classical nature of some of its foundations. Bohr strongly expected that the key to solving this problem was to be found in some way of introducing Planck’s law of quantum action.
In the beginning of 1913 Bohr heard about Rydberg’s remarkable discovery in spectroscopy. Rydberg’s formula could represent the frequencies of the lines of the hydrogen spectrum in the simplest form in terms of two integers. As soon as Bohr saw this formula, he immediately recognized that it gave him the missing clue to the correct way to introduce Planck’s law of quantum of action into the description of the atomic systems. The rest of the academic year was spent reconstructing the whole theory upon the new foundation and expounding it in a large treatise, which was immediately published as these three papers in the ‘Philosophical Magazine’. It was in these papers that Bohr first gave his postulates of the orbital structure of the electrons and their quantized radiation.
Bohr’s atomic theory inaugurated two of the most adventurous decades in the history of science. In 1922 Bohr was awarded the Nobel Prize “for his services in the investigation of the structure of atoms and of the radiation emanating from them”.
Three parts. 8vo: (217 x 141 mm). Sewn in original orange wrappers; first and second parts blank, third printed (as issued), third part with printed title, front wrapper of part 1 nearly loose and front wrapper of part 2 starting. First part inscribed in Bohr’s hand ‘Fra Forfatteren’ (From the author), second and third part with his rubberstamp ‘Fra Forfatteren’. A fine, completely unrestored, and coherent set, all three with numbering to the upper left corner of the front wrappers, from the library of the Danish chemist Prof. Einar Biilmann (1873-1946).