Abstract: Photographic elements containing image-wise developable silver halide are developed in the presence of an oxathioether development activator according to the formula:R.sup.1 --A--(OCH.sub.2 CH.sub.2).sub.n --S--A'--(X--A").sub.m --Y--R.sup.2wherein:R.sup.1 is H, alkyl, hydroxyalkyl, or R.sup.2 --Y--(A"--X).sub.m --A'--S--,A, A', and A" is alkylene, with the proviso that A is a monovalent bond when R.sup.1 is hydrogen or alkyl or hydroxyalkyl,X is --OCO--, --SO.sub.2 --, --CONH--, or Y,Y is ligand or complexing function of the type of --S-- and --N(Q)-- (Q=H or alkyl),R.sup.2 is alkyl, which may be substituted by OH, or when Y is --N(Q)--, R.sup.2 together with Q may represent the atoms needed to complete a nitrogen-containing saturated ring,n is at least 2, and m is 0 or 1.The development activators can be used in black-and-white development or in color development. They can be incorporated in the photographic material or in the developing solution.

Abstract: An electrodialysis cell intended to be used for the electrolytic rejuvenation of ferricyanide bleach bath into ferricyanide comprises a vessel which is made of carbon and which serves as anode, and a cathode, the space defined by both electrodes being separated by a cationic permeable membrane which is a wall made of asbestos cement which has been treated with a strong acid to remove a substantial part of the cement. The elements of the cell preferably have a cylindrical structure and are concentrically arranged with respect to each other.