Visual sensation in the alternating magnetic field

In a recent note published in the Proceedings of the Royal Society (B. 82, 557) Professor S. P. Thompson describes a simple experiment by which an influence of the magnetic field on visual perception has been detected. The subject's head was placed inside a coil which carried an alternating current and the result described is the perception of a sensation of light even with the eyes closed. It is also stated that this apparent light flickers.