โ Scribed by C.J. Bakker
No coin nor oath required. For personal study only.
In the last few years of the 19th century some physical phenomena of utmost importance were discovered which directed physical research for a long time. Although the discoveries of X-rays by R6ntgen and of radio-activity by B e c q u e r e 1 perhaps attracted more general attention it may be safely stated that the discovery of the magnetic separation of spectral lines in 1896, now 50 years ago, by P. Z e e m a n inaugurated a new epoch in the development of the understanding of atomic phenomena.
It had been the view of Faraday and Maxwell and especially also of L o r e n t z that the optical properties of matter originate from tile motions 6f electrical particles inside the atoms.
Already Z e e m a n's first experiments, which only showed a broadening of the sodium-D lines in a magnetic field, gave an excellent confirmation of L o r e n t z theory, as to the polarization of the differents parts of the broadened lines. According to theory longitudinal observation, in the direction of the magnetic lines of force, must show a symmetric doublet with oppositely circularly polarized, components, while on the other hand, with transverse observation, perpendicular to the direction of the magnetic field, a triplet must be observed with linearly polarized components : the undisplaced line in the centre vibrating parallel to the lines of force and both the outer components vibrating perpendicular to the lines of force. But still more impoltant was that from the sense of the circular polarization of the doublet components it followed that the particle responsible for the emission of light has a negative electric charge and that from
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