The Dictionary Of Photography

A True Historic Record Of The Art & Practice Of Photography 100 Years Ago.

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Hydroquinone
No. 3.
Potassium hydrate Distilled water...
2 ozs. 1 oz.
For normal exposure add 5 drops of No. 2 and No. 3 solutions to 1 oz. of No. i, and allow development to continue for some minutes; then add another portion of No. 3 to obtain the required density. For under-exposure omit No. 2, and gradually increase the accelerator No. 3 ; for over-exposure increase No. 2 to 10 drops to the ounce. The above quantities are for a |-plate. The following is recommended by a well-known firm of plate-makers : -
No. 1. .
Quinol ...
Sodium sulphite (cryst.)
... 160 grs. 2 ozs.
Citric acid
60 gr.
Potassium bromide
... 3o M
Distilled water to
20 ozs.
No.
2.
Sodium hydrate
...
160 grs.
Distilled water to
... ...
20 ozs.
To develop, mix equal parts of each. It is recommended to use the alum bath after development. May be used for negative or positive work. For positives, whether on glass or paper, the author recommends the following when black tones are wished for: -
No. 1.
Ouinol ... ... ... ... ... ... 154 grs.
Sodium sulphite (cryst.)         ...... ... 437 ..
Sulphurous acid          ... ... ... ... 20 mins.
Distilled water to make         ......... 10 ozs.
No. 2.
Sodium carbonate Potassium hydrate ..         bromide
Distilled water to make
1300 grs.
154 .. 20 .. 10 ozs.
Mix in equal parts, and dilute with three times the quantity of water. The following will give good purplish tones to trans-parencies on glass, and brownish tones to bromide paper": -
396