Chapter VIII On the Theory of Positive Printing
| Section I.—The Preparation of the Sensitive Paper.—Its darkening by light.—The conditions which affect its sensitiveness and the vigour of the Image.—The colour of the print influenced by the preparation of the paper | 121 |
| Section II.—The Processes for Fixing and Toning the Proof.—Conditions of a proper fixing.—The Salts of Gold used as toning agents.—The properties of the single fixing and toning Bath, with the conditions which affect its action | 128 |
| Section III.—The Author’s Photographic Researches.—The chemical composition of the Photographic Image.—The various agencies destructive to Photographs.—The action of damp air upon Positive Prints.—The change in properties of the fixing Bath by constant use | 140 |
Section IV.—The Fading of Photographic Prints.—The causes which produce it.—The comparative permanency of Prints.—The mode of testing permanency 160