1. Recent Work in Nuclear Physics and Quantum Dynamics I. The Primary Particles of Matter
2. Jules Henri Poincaré (1854–1912), professor at the University of Paris from 1886. One of the most versatile of mathematical geniuses, he contributed widely to the advanced study of celestial mechanics, electron theory, and other subjects of physical interest in addition to extensive researches in pure mathematics. To physicists his work in celestial mechanics and the theory of perturbations assumed major importance during the heyday of the Bohr theory of the atom. For a biographical sketch see Proc. Roy. Soc. A91 (1915).
3. Hendrik Antoon Lorentz (1853–1928), professor of physics at the University of Leyden from 1877 to 1912. The theory of electrons, in its broader sense, may perhaps be said to have been the principal work of Lorentz’ life. His approach to problems was fascinating for its clarity, and his writings are marvels of scientific literary composition. During the later years of his life he enjoyed the singular esteem of physicists everywhere, and contributed much to the progress of theoretical physics by his lectures and discussions at various congresses. An obituary notice and review of his life is given in Proc. Roy. Soc. A121 (1928).
4. On the quantum theory of the electromagnetic field