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.
Black Comet-Like Specks In The Enlarged Negative And Also In The Large And Small Transparency. This is generally caused by iron rust in the water or undissolved particles of Pyro. If these settle on the plate when it is first placed in the developer, they are apt to cause these spots. Filter the developer.
8G0. White Spots, Irregular in Shape, in the Enlarged Negative. - Caused by iron rust in the developer or wash waters. These spots will appear opaque on the transparency, and prevent the light from passing through them, thus producing light spots, which will result in black spots on the finished print.
Light Transparent Spots On The Transparency. These are caused by small air-bells gathering on the plate when developing, and which, when enlarged, will produce black spots on the enlarged negative, resulting in white spots on the finished print. Carefully dust the negative and transparency and also filter the developer.
Enlarged Negative Too Strong In Color-Yellow. Strengthen the Sulphite of Soda and this will be readily overcome. Also bear in mind that Sulphite of Soda, even though it tests full strength, if it has been made up for some time and is an old solution, will not have the same chemical value as a fresh solution, and should be discarded and a fresh solution be made up.
Negatives That Have Been Properly Exposed When Enlarging From A Small Transparency, Or A Transparency That Has Been Properly Exposed When Enlarging From A Small Negative, Appearing Hazy Or Fogged. This would result if the light were allowed to enter between the lens and the negative, or transparency. A hood or cloth must be used over the space between the lens and negative or transparency being enlarged from.
Kerosene Light Flickers. This is a certain sign that the box is not properly ventilated. It must be ventilated from the bottom and also from the top in order to have the lamp burn steady. This will also apply to gaslight.