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Niels Bohr Collected Works Vol 4: The Periodic System (1920–1923)

J R Nielsen (ed) Amsterdam: North-Holland 1977 pp ix + 765 price $120.50 Volume 4 of the collected works of Niels Bohr (a fundamental contribution to the History of Science in the XXth century, started by the late Leon Rosenfeld in collaboration with J Rud Nielsen, editor of the present volume) contains the papers, lectures and correspondence of the 1920–1923 period and the Encyclopaedia Britannica article of 1926, all concerned with the problem of atomic structure and the periodic table. It is a fascinating series of documents which describe the various attempts to achieve a consistent picture of the electronic constitution of the elements.