Cooley's Cyclopædia of Practical Receipts and Collateral Information in the Arts, Manufactures, Professions, and Trades..., Sixth Edition, Volume I

by Arnold James Cooley; Richard Vine Tuson

[282] See Voltaic Electricity.

Etching Fluids. 1. (For COPPER.)—a. From ‘aquafortis,’ 2¹⁄₂ fl. oz.; water, 5 fl. oz.; mix.

b. To the last add of verdigris, 1 oz.; water, 2¹⁄₂ fl. oz.; dissolve. For light touches.

c. (Eau forte,—Callot and Piranesi.) Alum, sal-ammoniac, sea salt, and verdigris, of each 4 oz.; vinegar (pyroligneous acid), 8 fl. oz.; water, 16 fl. oz.; mix, dissolve, boil for 1 or 2 minutes in a glazed or stoneware vessel, cool, and decant the clear portion. Used as the last.

d. Water acidulated with sulphuric acid. Used in the process of electro-etching.

2. (For STEEL.)—a. From iodine, 1 oz.; iron filings or wire, ¹⁄₂ dr.; water, 4 fl. oz. It must be kept in a stoppered bottle, until required for use.

b. From iodine, 3 dr.; iodide of potassium, 1 dr.; proof spirit, 1 fl. oz.; water, 2 fl. oz. As the last.

c. (Mr Turrel.) Pyroligneous acid, 4 fl. oz.; alcohol (rectified spirit), 1 fl. oz.; mix, and add of nitric acid or double aquafortis (sp. gr. 1·28), 1 fl. oz.

d. From hydrochloric acid, 5 parts; water, 95 parts; mix, and add the liquid to a solution of chlorate of potassa, 1 part, in water, 50 parts.

e. A solution of common salt. Used in the process of electro-etching.