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.
Plates Developing Too Slowly. If the plate develops too slowly it is either because the developer has been diluted too much, it is too cold, or it has become exhausted by long use. Carefully test the temperature and if this is correct your bath has become exhausted, therefore, make up a fresh bath exactly according to formula. With a fresh bath made according to formula slow development will not occur.
Plates Develop Too Fast. If the developer is too strong, or too warm, the plates will develop too fast. Remedy: obvious.
Plates Develop Unevenly. If the developer is not thoroughly mixed, the plates will develop unevenly. When adding water to make up the bulk of developer thoroughly stir the solution to insure proper mixing. It is well to occasionally shake the tank during development.
Plates Develop In Streaks. If the developer is too strong, and develops too quickly, the plates are apt to develop in streaks. Dilute the developer by adding more water and mix well. It is not advisable to use a faster bath than twenty minutes for pyro, or ten minutes for metol. Always shake a bath well before admitting the plates.
Pin Holes. When the plates are first immersed in the developer air-bells are apt to gather on the surface of the plate, and if these are not removed will cause pin holes and transparent spots. When first placing the plates in the tank raise and lower them two or three times very carefully; this will remove the air-bells. Sometimes air in the water will cause air-bells; to use cold boiled water will overcome this difficulty.
Spots And Pin Holes On Plates That Are Not Caused By Air-Bells. These are sometimes caused by particles of dirt in the developer. Always filter old developer before using.
537. Negatives Contrasty - If the plates are properly exposed this can only occur when the developer is not properly balanced, and there is too much of the developing agent in the developer. Even diluting with water will not overcome this, and it clearly shows that you must have made a mistake in the quantity of developing agent used. It will be advisable for you to make up a fresh bath. An excess amount of bromide will also give similar results. An over - worked bath also contains considerable bromide, eliminated from plates previously developed.
Negatives Develop Flat. Either the plates are badly over-exposed or the developer is weak in developing agent. Possibly the stock solution which contains the developing agent was not correctly prepared, not enough of the developing agent added. Where long factor developing is resorted to (using weak solutions), the image, during the first three-fourths of the period of development, is flat, the contrast gaining rapidly at the latter end. Developing longer will give you stronger negatives, but you will likely find your trouble was in preparing your developer.