XLI. Some experiments on photographic sensitivity

Abstract

Abstract A technique is described for the preparation of optically clear silver bromide in the form of thin plane parallel sheets with flat surfaces. These sheets have been used to investigate the formation of the latent image under illumination. It has been found that the distribution of the latent image between the surface and the interior of the crystals depends on their physical properties, on the nature of the sensitizing layers present on their surfaces, and on the exposure. A surface latent image is formed, together with a weak internal latent image, when well annealed crystals are exposed to light. A surface latent image, on the other hand, is not formed with strained sheets of pure silver bromide, if they have not been annealed at all or only at low temperatures. With such material, an internal latent image is formed by the separation of silver along dislocation lines, which may form the boundaries of an irregular polyhedral structure. The crystals may then be developed after the dissolution of t...