To Dye Silk a Gold Color.

Scientific American 47, 12.8.1848

Take any quantity of nitro-muriate of gold and evaporate by exposing it to a gentle heat in a glass tumbler or phial; the gold will form itself in crystals on the bottom and sides of the vessel; collect these crystals and dissolve them in ten times their weight of pure water. Then put a gill of water into a common flask, and add one ounce of granulated zinc, and one fourth of an ounce of sulphuric acid. - Hydrogen gas will be evolved, and rise through the neck of the flask, which must not be stopped. Immerse a piece of white silk in the above mentioned aqueous solution of gold, and expose it, while wet, to the current of gas as it rises from the flask; the gold will soon be revived, and the silk will become beautifully and permanently gilt. Any letters or flowers may be drawn on the silk with a camel-hair pencil dipped in the solution, and on being exposed to the action of the gas, will be revived and shine with metallic brilliance. The silk must be kept moist with water till the gold is revived.

This is mere ornamental operation, but nitric acid itself diluted with water and kept near the boiling point, will dye silk a beautiful, cheap and permanent salmon color. This is a simple process and a practical method. - Good colors are dyed upon silk in manufactories, by first dyeing the silk a light orange in a solution of annatto dissolved in soda, then washing the silk and running it through a strong bath of quercitron bark liquor and muriate of tin kept near the boiling point for some time. This process of dyeing gold and amber colors on silk is practical and makes a most brilliant metallic color.

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