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.
398. Development Slow. Image Over Five Minutes in Making Appearance. - If the plate has been sufficiently timed the image should begin to appear within two minutes, even though an extremely small quantity of carbonate has been used. If the developer is too cold the image will be very slow in appearing. If the temperature is correct, add a few more drops of carbonate, and continue adding a few drops at a time until the image does make its appearance.
Image Flashing Up At Once. This would happen if the plate was extremely over-exposed, and too much carbonate of soda had been used to begin with, and possibly the developer too warm. If the plate acts this way place it at once in a restraining bath, either old developer, or add five drops of bromide to your special developer. This should not occur, even if plate was considerably over-timed, provided you have not used too much carbonate of soda. Long exposure requires less carbonate, and the shorter exposure more.
Obtaining Proper Strength. If the plate has been sufficiently exposed and you have added your carbonate of soda too rapidly, or using too strong a solution you will produce flatness, and no strength. On the other hand, if you do not add carbonate of soda often enough, the plate will remain weak, and develop extremely slow. After you have produced all the detail in the drapery, and find that the highlights hold back, and do not build up strong enough, place the plate for a few seconds in a normal developer. In this way you will obtain the necessary strength to produce highlights.
Plate Fogging. A plate extremely over-exposed, with too much carbonate of soda used, is apt to fog. As in this method the development is extremely slow, it is advisable to keep the plate as far away from the ruby light as possible. It is also a good plan to use a cover over your developing tray. Air coming in contact with the developer will cause oxidation, which is apt to produce a scum and foggy effect on the plate.
Plate Very Thin After Fixing. Possibly under-developed, or too much carbonate of soda has been used. It is generally caused by under - development. You should bear in mind, however, that these plates are expected to appear somewhat thin, although you will find that they will have more printing strength than their appearance would lead you to believe.
No Detail In Shadows. This is generally caused by underexposure, and then using too little carbonate.
Highlights Too Strong, Losing All Detail. This will occur if the plate has not been sufficiently exposed, and too much carbonate is used. It will also occur if the plate has been sufficiently exposed, but the carbonate added in too great quantities and too frequently during development. Usually not more than one-half ounce all told of carbonate is ample to fully develop any plate.