The measurements described in Dr. Hemphill's paper are nominally of resistance to a direct current, but in view of the well-known variations in resistance according to the frequency used, it seems most probable that the actual phenomena reported are due not only to changes in resistance proper, but also to fluctuations in the E.M.F. generated by the superficial tissues, as a result of the small steady polarizing current used in the Wheatstone bridge circuit.