Petr Alexeyevich Zilov (3.02.1850-1.05.1921) was a Russian physicist. He graduated from Moscow University (1873) and furthered his knowledge at the Universities of Heidelberg and Berlin. In 1877 — 84 he worked at the Moscow Technical School and from 1884 at the University of Warsaw. In 1905—12 he was curator of the Kiev educational district.
In 1877 he was the first to measure the permittivity of certain liquid dielectrics and proved that the relation between permittivity and refractive index holds for them. He confirmed experimentally the important proposition of Maxwell's theory about the part played by the medium in electrodynamic interactions. In 1879 he established how the magnetic permeability of liquids depends on the magnetic field strength.
Publisher of the journal “Physical Review”.