This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
Sulphite of Soda ( Anhydrous )...
Bromide of Potassium..... ....
Carbonate of Soda ( Anhydrous ) ,
Directions For Use. For a twelve-minute developer this metol - hydroquinone formula must be diluted as follows: To every ounce of the developer add four ounces of water. If it is necessary to have twenty-five ounces of solution to fill the tank, take five ounces of the developer and add twenty ounces of water. If more solution is necessary to fill the tank increase the quantity by adding more developer and water, but always keep the proportions the same, and the temperature of the developer should never be under sixty degrees, or above seventy degrees Fahr. This bath will fully develop a plate in from ten to twelve minutes.
The Film Developing Holder. The individual films are taken from the film pack, and a film placed in the holder. The holder is then inserted in the developing tank in exactly the same manner as the plate, and development proceeds accordingly. These holders are made in all the popular sizes, and as they list at a very reasonable price there is no reason why this very convenient accessory should not be in the hands of every user of the film pack.