68. To cleanse Gold.—Wash the article in warm suds made of delicate soap and water, with ten or fifteen drops of sal-volatile. (The sal-volatile will render the metal brittle. This hint may be used or left, at pleasure.)
69. To clean Brass and Copper.—Rub it over slightly with a bit of flannel dipped in sweet oil; next, rub it hard with another bit dipped in finely-powdered rotten stone; then make it clean with a soft linen cloth, and finish by polishing it with a plate-leather.
70. Obs.—The inside of brass or copper vessels should be scoured with fullers' earth and water, and set to dry, else the tinning will be injured.
71. Another way to clean Brass and Copper.—Put one pennyworth of powdered rotten stone into a dry, clean quart bottle; nearly fill it up with cold soft water; shake it well, and add one penny-worth of vitriol. Rub it on with a rag, and dry it with a clean, soft cloth, and then polish it with a plate-leather. This mixture will keep for a long time, and becomes better the longer it is kept. But the first method gives the most lasting polish, as well as the finest color.
72. To clean Brass Ornaments.—Wash the ornament in a strong solution of boiled roche-alum, in the proportion of an ounce to a pint of water. When dry, rub them with fine tripoli powder.