Knowns and unknowns in the theory of development

✍ Scribed by S.E. Sheppard; F.A. Elliott

• Publisher: Elsevier Science
• Year: 1924
• Tongue: English
• Weight: 69 KB
• Volume: 198
• Category: Article
• ISSN: 0016-0032
• DOI: 10.1016/s0016-0032(24)90078-0

✦ Synopsis

CRITICAL consideration of the sensitometric, microscopic, and physico-chemical aspects of the subject. Neither of the simple assumptions that rate of development is determined primarily ( I ) by the rate of chemical reaction between the silver halide and the reducer, or (2) by the diffusion processes involved, is adequate to account for the sensitometric data available. A tentative hypothesis of the mechanism of the development process is based on the assumption of selective adsorption of the reducing agent by the silver halide grains.

This adsorption may be assumed to be followed by an intramolecular oxidation-reduction reaction, which is catalyzed by the latent image. The r6le of alkalies in development is intimately related to the action of the hydroxyl ion, which probably exercises a determinative influence upon the equilibrium between the polar (strongly adsorbed) and non-polar (less active) tautomeric modification of the reducing agent.

CORROSION OF MONEL METAL IN

PHOTOGRAPHIC SOLUTIONS.