1. It was introduced as a developing agent for photographic papers in 1892. 2. In 1969, he began experimenting with the forgotten photographic developing agent Pyrogallol. 3. Sodium carbonate is also used as a relatively strong film developing agents . 4. It uses derivatives of ascorbic acid ( vitamin C ) and phenidone as developing agents . 5. Other developing agents in use are p-aminophenol, glycin ( N-( 4-hydroxyphenyl ) glycine ), pyrogallol, and catechol. 6. Spagnoli at first hesitated to make daguerreotypes because one of the main developing agents is deadly mercury vapor. 7. A brief exposure to a negative produces a latent image, which is then made visible by a developing agent . 8. Developing agents are commonly hydroxylated benzene compounds or aminated benzene compounds, and they are harmful to humans and experimental animals.9. Glycin is rarely used as a developing agent today, primarily because it is expensive and manufactured for specialty applications only. 10. Ascorbic acid and its isomers, and other similar sugar derived reductone reducing agents are a viable substitute for many developing agents .
