The Charge Effect in Photographic Development: Role of the Gelatin

Abstract

The approach of negatively charged developer ions to the surface of a silver bromide grain is opposed by charge barriers originating both with the gelatin and with the adsorbed bromide ions. It is shown that the effect of neutral salt upon the rate of development by negative ions results primarily from a depression of the gelatin charge barrier. The effect of salt upon the bromide barrier is relatively unimportant. On the other hand, a change in the bromide barrier is mainly responsible for certain other kinetic effects, such as the induction period in development and the accelerating action of phenosafranin.