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THE PHOTO-MINIATURE This is said to be "95 per cent pure paramidophenol-sulphate," nevertheless the following formula (without caustic soda) is advised for tank development: Water, I gallon; Mitus, ~ ounce; hydroquinone, ~ ounce; sodium sulphite, 5 ounces; sodium carbonate, 3 ounces; potassium metabisulphite, So grains; potassium bromide, 2 5 grains. Add water to make the bulk of the solution up to 5 gallons. Develop 20 minutes at 65째 Fahr. For development papers use the second Kathol formula above, but substitute an equal amount of Mitus for the Kathol specified in that formula. This is a British product which is Serc:hol probably paramidophenol-sulphate or the hydrochloride salt of high grade. It can be used with hydroquinone for development papers; with pyro for plates and films; or alone as a single-solution developer for plates or papers. Typical formulas are as follows: For bromide and gaslight papers, and lantern slides: Water, 20 ounces; Serchol, 6 grains; hydroquinone, 18 grains; sodium sulphite (cryst.), 120 grains; sodium carbonate, 120 grains; potassium bromide, 1 grain. For tank development, 20 minutes at 65째 Fahr: Water, 36 ounces; Serchol, 6 grains; hydroquinone, 18 grains; sodium sulphite (cryst.), I~ ounces; sodium carbonate (cryst.), 120 grains; potassium bromide (10 per cent solution), 10 drops. The Serchol-Pyro formula is said to be especially advantageous for cases of known underexposure. Make up two solutions, as follows: No. I Water, 20 ounces; Serchol, 40 grains; pyro, 48 grains; potassium metabisulphite, 100 grains. No. 2-Water, 20 ounces; sodium carbonate (cryst,). 2 ounces; potassium bromide, 10 grains. For use take equal parts, increasing the proportion of No. 2 where under-exposure is known or indicated. Tonall is a developer of American Tonall manufacture offered as "the most perfect equivalent for metol on the market." The chemical name is given as mono-methylparamidophenol-chloride, which must be a printer's blunder I It is said to keep well in solution, is suitable llitua

Modern Photographic Developers  

A Practical Handbook to the New Developers Telling What They Are and How to Use Them with Reliable Formulae by The Photo Miniature, January...

Modern Photographic Developers  

A Practical Handbook to the New Developers Telling What They Are and How to Use Them with Reliable Formulae by The Photo Miniature, January...

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