I

Pure water......... 30 ounces

Sulphite soda, crystals ............ 5 ounces

Carbonate soda, crystals......... 2.5 ounces

II

Pure water......... 24 ounces

Oxalic acid........ 15 grains

Pyrogallic acid..... 1 ounce

To develop, take of

Solution No. 1...... 1 ounce

Solution No. II..... 0.5 ounce

Pure water......... 3 ounces.

More water may be used in warm weather and less in cool weather.

If solution No. I is made by hydrometer test, use equal parts of the following:

Sulphite soda testing, 80°. Carbonate soda testing, 40°. One ounce of this mixture will be equivalent to 1 ounce of solution No. I.

Pyro and Potassium Developer

I

Pure water......... 32 ounces

Sulphite soda, crystals ............ 8 ounces

Carbonate potassium, dry........ 1 ounce

II

Pure water......... 24 ounces

Oxalic acid........ 15 ounces

Pyrogallic acid..... 1 ounce

To develop, take of

Solution No. 1...... 1 ounce

Solution No. II..... 0.5 ounce

Pure water......... 3 ounces

When the plate is fully developed, if the lights are too thin, use less water in the developer; if too dense, use more water.

Pyro and Metol Developer

Good for short exposures:

I

Pure water......... 57 ounces

Sulphite soda, crystals ............. 2.5 ounces

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

II

Pure water......... 57 ounces

Sulphite soda, crystals ............. 2.5 ounces

Pyrogallic acid..... 0.25 ounce

III

Pure water.........   57 ounces

Carbonate potassium............ 2.5 ounces

To develop, take of

Pure water......... 3 ounces

Solution No. 1...... 1 ounce

Solution No. II..... 1 ounce

Solution No. III.... 1 ounce

This developer may be  used repeatedly by adding a little fresh developer as required.

Keep the used developer  in a separate bottle.