Aimé Cotton (9.10.1869-15.04.1951) was a French experimental physicist and a member of the Paris Academy of Sciences (1923), and its president in 1938. He was born in Bourg. He graduated from the École Normale (1893). In 1895-1900 he was a lecturer in Toulouse, in 1900 — 20 professor at the École Normale and in 1920—42 at the University of Paris.
His research concerned magnetism, optics, magneto-optics, acoustics and atomic physics. He built a powerful electromagnet and an instrument for measuring magnetic fields. Together with A. Mouton he discovered in 1907 double refraction in substances placed in a magnetic field when light propagates perpendicular to the field (the Cotton–Mouton effect). He designed (1923) a piezoelectric transmitter and receiver of low-frequency acoustic waves based on a crystal of Rochelle salt. He studied anomalous dispersion, dichroism, the Zeeman effect and other phenomena. He discovered anomalous optical activity.