I

Water............. 8 ounces

Metol.............100 grains

Sulphite of soda, crystals......... 1 ounce

II

Water............. 10 ounces

Potassium carbonate 1 ounce Take equal parts of I and II and 6 parts of water. If more contrast is needed, take equal parts of I and II and 3 parts of water, with 5 drops to the ounce of a 1/10 solution of bromide of potassium.

Metol and Hydrochinon Developer

I

Pure hot water..... 80 ounces

Metol............. 1 ounce

Hydrochinon....... 1/8 ounce

Sulphite soda, crystals ............. 6 ounces

* For double-coated plates use 5 ounces of water.

II

Pure water.........   80   ounces

Carbonate soda, crystals..........     5    ounces

To develop, take of

Pure water.........     2    ounces

Solution No. 1......     1    ounce

Solution No. II.....     1    ounce

Metol-Bicarbonate Developer

Thoroughly dissolve

Metol............. 1 ounce

In water........... 60 ounces

Then add

Sulphite of soda, crystals.......... 6 ounces

Bicarbonate of soda. 3 ounces

To prepare with hydrometer, mix

Sulphite of soda solution, testing 75.. 30 ounces

Bicarbonate of soda solution, testing 50 30 ounces

Metol............. 1 ounce

Dissolved in 12 ounces water.

Ferrous-Oxalate Developer

For transparencies and opals.

I

Oxalate of potash. . . 8 ounces

Water............. 30 ounces

Citric acid......... 60 grains

Citrate of ammonia solution......... 2 ounces

II

Sulphate of iron .... 4 ounces

Water............. 32 ounces

Sulphuric acid...... 16 drops

III

Citrate of ammonia solution saturated. Dissolve 1 ounce citric acid in 5 ounces distilled water, add liquor ammonia until a slip of litmus paper just loses the red color, then add water to make the whole measure 8 ounces.

Add 1 ounce of II to 2 of I. and 0.5 ounce of water, and 3 to 6 drops of 10 per cent solution bromide potassium.

To develop, first rinse developing dish with water, lay film or plate down, and flow with sufficient developer to well cover. Careful attention must be given to its action, and when detail is just showing in the face, or half-tone lights in a view, pour off developer, and well wash the film before placing in the fixing bath.