Two experiments of I. K. Kikoin -- the correlation between superconductivity and the galvanomagnetic properties of metals (1933), and the gyromagnetic effect in superconductors (1938) -- which were carried out long before the appearance of the microscopic theory of superconductivity, anticipated two of its principal conclusions. Established were: 1) the determining role of electron-phonon interaction; 2) the orbital nature of diamagnetism in superconductors.