The Blackness of Developed Silver

Paper presented at the “Congres International de Science Photographique” held in Paris, in September 1965.

Abstract

Newton suggested and others have shown that increased blackness of solids correlates with increasing fineness of structure. The same relationship was shown to hold with developed silver by using crystallographic line-broadening to estimate fine structure: the blacker the silver, the smaller was the calculated crystallite size. Independent estimates of fine structure were obtained by saturating the silver surfaces with thiosulphate, and selectively bleaching the silver image. Both silver sulphide stain and surface volume ratio (calculated from Ag₂S Ag ratio) increased progressively with increased blackness, and all these properties correlated with decreasing crystallite size.

Notes

Paper presented at the “Congres International de Science Photographique” held in Paris, in September 1965.