The Quantum Theory of the Atom

1. The origin of the quantum theory; Planck's radiation formula; 2. The nuclear theory of the atom; Bohr's theory of the hydrogen spectrum; 3. The correspondence principle; the photo-electric effect; Einstein's deduction of Planck's formula; 4. The adiabatic principle of Ehrenfest; the stationary states of a periodic system; 5. General dynamical theory; 6. Contact transformations; the Hamilton–Jacobi differential equation; 7. The use of angle variables; multiply periodic systems; 8. The relativity theory of the fine structure of the hydrogen lines; electron in a central field; 9. The Stark effect; 10. The Zeeman effect; 11. The series spectra of the elements; 12. The multiple structure of series lines; theory of the Ritz formula; 13. Arc and spark spectra; excitation of lines by electrons or radiation; 14. X-ray spectra; 15. Absorption spectra and absorption edges; Bohr's table of the atomic structures of the elements; 17. Band spectra in the infra-red; 18. Band spectra in the optical region; molecular rotation and specific heat; 19. The Keplerian orbit; the Delaunay elements; 20. The astronomical theory of perturbations and atom mechanics; 21. General perturbation theory; 22. The effect of electric and magnetic fields on the spectra of elements of higher atomic number. Recent developments of the quantum theory: the doublet theories of Sommerfield and Landé; the dispersion theory of Kramers; the quantum-kinematics of Heisenberg; Index of authors.