Pieter Zeeman

“The magnetic separation of the spectral lines has been of the first importance in the development of the theory of the constitution of the atom.”

“It appeared to me that it would be of great interest to investigate how the light of a flame is changed when the flame is placed in a strong magnetic field.”

“Lorentz’s theory, on the other hand, gave a complete explanation of the new phenomena.”

“A threefold splitting of the spectral line is observed.”