Migration of silver ions from bulk gelatin to the surface of silver halide grains takes place in the print-out process of silver-ion excess emulsions. The electrical conductivity of gelatin films containing silver ion was measured and the transport number of silver ion determined to know to what extent the silver ions are mobile in gelatin. The initial conductivity was of the order of 10^-7-10^-6 ohm^-1 cm^-1 depending on silver-ion content and applied voltage. The transport number of silver ion was 0.65 for a film containing 10^-3 mol g^-1 silver ion electrolysed for 5 min in the field of about 10₃ volt cm^-1. Itdecreased with decreasing silver-ion content and with increasing time of electrolysis. The current which passed through films decreased rapidly during the first few minutes due to polarization and then slowly due to electrolysis.