Development by Hydrazine

Abstract

The reduction of silver bromide in alkaline solution by hydrozine yields four atoms of silver per molecule of hydrazine. Development of a (lne-grain bromide emulsion takes place at pH levels obove 12 at a rate proportional to the concentration of hydrazine and to the hydroxyl ion concentrotion. The (lrst and rate-determining step is the loss of a single hydrogen ion and an electron from the hydrozine. The density-time plots are sigmoid with a deep toe curvature. E/ectronmicrographs of the developed particle population ot various stages show that the density grows by the increase in the number af centres reaching the developable stage.