Abstract: The reducing properties of photographic gelatins have been determined and compared by potential titration. The magnitude of the reducing property of different kinds of gelatins can be arranged in the following sequence: active > semi-active> inert >deionized. The inert gelatins of the same kind have been shown to be different in their reducing property. This difference can be attributed to the different kind and amount of reducing agents contained in gelatin, depending on the processing technology of gelatin manufacture and post-treatment. The results of reducing property in present paper can be used to explain, in part, the difference of various gelatins in their photographic property.

Key words: photographic gelatin, reducing property of photographic gelatin, potentiometric titration, inert gelatin