Alum, 1 oz.; fine table-salt, 1 oz.; saltpetre (powdered,) 2 oz.; hot rain-water, sufficient to make the solution, when dissolved, about the consistency of thick ale; then add sufficient muriatic arid to produce the color desired. The degree of success must always depend, in a greater or less degree, upon the skill or Judgment of the operator. The article to be colored should be from Fourteen to eighteen carats fine, of pure gold and copper only, and be free from coatings of tin or silver solder. The solution is best used warm, and when freshly made the principle on which it acts is to eat out the copper alloy from the surface of the article, leaving thereon pure, frosted gold only. After coloring, wash off, first in rain-water, then in alcohol, and dry without rubbing, in fine, clean saw-dust. Fine Etruscan jewelry that has been defaced or tarnished by use may be perfectly renewed by the same process.

Tarnish on Electro-plated Ware may be removed by immersing the article from one to ten or fifteen minutes, or until the tarnish has been removed, but no longer, in the following solution: Rainwater, 2 gals.; cyanuret potassa. ½ lb.; dissolve and put Into a stone jug or jar and closely cork. After immersion, the articles must be taken out and thoroughly rinsed in two or three Waters, then dried with a soft linen cloth, or, if frosted or chased work, With fine, clean saw-dust. Tarnished jewelry may be speedily restored by this process; but make sure work of removing the alkali. otherwise it will corrode the goods.

A Bright Gold Tinge may be given to silver by steeping it for a suitable length of time in a weak solution of sulphuric acid and water strongly impregnated with iron-rust.