A Technique for Examination of the Edge Faces of Tabular Microcrystals Applied to Silver-Bromide Grains for Evidence of Twinning†

Abstract

By coating spherical microcrystals on to a glass support prior to a coating of tabular micro-crystals, many of the latter are lilted so that the topography of their edge faces is readily visible in carbon-replica electron micrographs. Electron micrographs are reproduced of tabular silver-bromide microcrystals (grains) from a photographic emulsion examined in tliis way, which show that the edge faces of many grains are of the form to be expected if twinning had occurred during grain growth. The significance of certain findings is discussed briefly.