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.
Strength Of Silver Bath. The proper strength of the silver bath should be anywhere from 45 to 50 grains of silver to the ounce of solution. The simplest method for testing the bath is with the hydrometer, which will give you an accurate test of your solution. When the bath falls below 45° the strength should be increased by the addition of a few grains of nitrate of silver crystals until it registers the proper strength. Should it be too strong, it may be diluted by the addition of distilled water until it tests the required strength.
893. Flow a glass plate with the regular iodized collodion, place it in the silver bath, and allow it to remain there for several hours. No harm will be done to allow it to remain over night in the bath.
Testing Bath. After the bath is iodized it should be tested with blue litmus paper, which paper should turn red almost instantly upon entering the bath. With the bath testing acid being iodized with the collodion-ized plate, it should then be filtered ready for use. A simple way to filter the bath would be to prepare a large, clean bottle. Place a piece of absorbent cotton in a glass funnel, first wetting the cotton with distilled water. Place the funnel in the bottle and pour the silver bath into the funnel, allowing it to filter slowly into the large bottle; then rinse out your silver bath dish, to receive the filtered solution. After all the solution is filtered into the bottle transfer the solution into the silver bath, when it is ready for use.
The Developer. For the developing of the wet plate numerous developers are used. These, however, unlike the developers for the modern dry plate, contain no accelerator, but work in an acid state. They consist merely of a reducer dissolved in water. In order to get the developer flowing evenly it is sometimes necessary to add a small quantity of alcohol.
Formula For Developer.
Alcohol in sufficient quantity to make the solution flow freely. Usually 1/2 ounce is sufficient.
Another Good Developer.
Ammonium Sulphate of Iron
1 1/4 ozs.
Glacial Acetic Acid
1 1/4 ozs.
Note. - The formula for this developer calls for small quantities only when preparing your developer. However, a gallon or more should be made up at a time and prepared in the above proportions. The amounts given in the formula will be sufficient for experimental purposes.