Fig. 56c. the pin-hole camera complete with cloth and rubber band
Rock the tray after you have poured the developer over the plate to keep the solution flowing forth and back evenly over it all the time. When you see the image very plainly take the plate out of the developer, wash it in clean water and then lay it with the film side up in a tray containing the fixing bath.
Let the negative—when the plate is exposed and developed it is called a negative—remain in the fixing bath until all the white parts, that is, the free silver which was not affected by the light, have disappeared and then let a gentle stream of water run on it for an hour or wash it in 16 changes of clean water. Stand it in a negative rack over night to dry and then you can make prints from it.
How to Make the Developer.
—You can make a good, tried and true developer in two solutions as follows:
Pyro Solution, A.—Take 1 ounce of pyrogallic acid, called pyro for short, dissolve it in 28 ounces of water and then add 20 minims of sulphuric acid.
Soda Solution, B.—Dissolve 2 ounces of desiccated[50] carbonate of soda and 3 ounces of sulphite of soda in 28 ounces of water.
[50] Desiccate means thoroughly dry.
When you want to develop a plate mix ¹⁄₂ an ounce of the pyro solution and ¹⁄₂ an ounce of the soda solution with 4 ounces of water and to do this you need a graduated glass.