[24] Crocus is a powder made of iron rust.
Coloring Metals.
—Many things that you make of metal can be greatly improved in appearance by coloring them.
Bluing Steel.
—First polish the articles and clean them by immersing them in a hot solution of caustic soda. Now put the screws, or whatever it is you want to blue, in an iron pan half full of dry, clean sand and heat them over a fire.
Keep moving the articles around with a pair of tweezers until they are the color you want them and then drop them into clean oil.
Bluing Brass.
—Polished pieces of brass can be given a fine color by putting them in a solution made as follows:
Stir 1¹⁄₂ drams of antimony sulphide,[25] 2 ounces of calcined soda in ³⁄₄ of a pint of water; to this solution add 2¹⁄₄ drams of kermes. Stir well, filter it and then mix it with 2¹⁄₄ drams of tartar, 5¹⁄₂ drams of hyposulphite of soda dissolved in ³⁄₄ pint of water when it is ready to use.
[25] This and all other chemicals can be bought of Eimer and Amend, Fourth Ave. and 18th Street, New York.