The mechanistic and synthetic aspects of the infectious development process

The basic photographic process involves the use of silver halide, usually bromide, with a small proportion of iodide in the more sensitive films. The silver halide is present as a dispersion of small crystals of diameter 0.1–1.5 μm in a colloidal binder of gelatin. This suspension of silver halide grains is termed the photographic emulsion. The gelatin has many important properties, one being that it suspends the crystals in warm aqueous solution during grain growth and sets to a jelly on cooling. The emulsion is prepared by forming and growing the silver halide by double decomposition between a soluble silver salt and mixed alkali halides. [Continues.]