Scientific American 22, 30.5.1863
Black on Gun-Barrels. - The following mode of producing a black coating on gun-barrels is taken from Mr. Wells's "Annual of Scientific Discovery" for the present year: - First, take chloride of mercury and sal-ammoniac; second, perchloride of iron, sulphate of copper, nitric acid, alcohol and water; third, perchloride and proto-chloride of iron, alcohol and water; fourth, weak solution of the sulphide of potassium. These solutions are successively applied, each becoming dry before the other is used. No. 3 is applied twice, and a bath of boiling water follows Nos. 3 and 4. The shade of color is fixed by active friction with a pad of woolen cloth and a little oil. The shade thus obtained is a beautiful black of uniform appearance. This process is used in the manufacture of arms at St. Etienne, France. We regret that the proportions of the different ingredients are not given. Several of our gunsmiths have made many inquiries as to the mode of producing the blue-black coating on the Whitworth and other English rifles. Perhaps the above solution will effect the object. The alcohol is used to make the application dry quickly. The perchloride of iron and the sulphate of copper in No. 2 should be used only in a moderately strong solution, and only about 10 per cent of nitric acid added to the water. We hope that out gunsmiths will meet with success in using these solutions. No. 2 applied in three or four coats, will form the common brown coating for gun-barrels. After the last application has become dry it is rubbed with a wire scratch brush, washed with warm water, then dried, and afterwards rubbed down with a composition of bees-wax dissolved in turpentine.
Dyeing Gloves. - Messes. Editors: - If you have lady readers, and I assume so, they must have occasion for a lively and beautiful drab color upon white or light-colored fabrics of cotton, silk, linen or wool, such as gloves, stockings, &c. They can produce a dye, which is quite permanent in its character, in five minutes, as follows: - To a pint of rain water add six or eight grains of nitrate of silver; when it is dissolved stir it well and immerse the perfectly clean fabric. See that it is well and evenly saturated, for which use a stick not a spoon nor the hands. When thoroughly soaked it may be quickly wrung out with the hands, they beings instantly washed. In a pint of water dissolve one quarter of an ounce of sulphuret of potassium, place the goods in it and saturate well, then wash in clear water and it is finished. It is better that the first-named solution should be hot, and a little time taken for wool. Glass vessels must be used. - R. H. A., Baltimore, May 11, 1863.