Langevin, Paul
Langevin was a student of Perrin in Paris and later worked there with Pierre Curie; in between he spent nearly a year with J J Thomson in Cambridge. His interests in physics were wide-ranging and he became the leading French physicist of his time.
Work on ionized gases led him to study the magnetic properties of gases; most are feebly diamagnetic (repelled by a magnetic field) but ozone (O3) is paramagnetic (weakly attracted into the field). Langevin showed in 1905 that magnetic behaviour could be understood in terms of the electrons present in atoms; electrons had recently (1895) been discovered by Thomson.
David Millar, Ian Millar, John Millar, Margaret Millar 1996, 2002
