Important: Safety Warning
This page describes trade processes that use dangerously toxic materials such as cyanide solutions, mercury amalgams, or strong acids. These processes require training, equipment, and precautions far beyond what the text describes.
This information has been left in for historical purposes but should not be acted upon.
Ormolu
A variety of brass having a near resemblance to gold, containing from 25 to 50 of zinc to 50 of copper, according to the tint desired. To successfully fuse this alloy, let the zinc be added to the fused copper at the lowest temperature possible, gradually introducing the zinc until the whole amount has been added. In many cases it is used for the ornamentation of furniture. A gold lacquer is sometimes used to heighten the color of the alloy, but the native color of the metal may be preserved if properly brought out by means of sulphuric acid, then washing in water, and applying a liquor varnish to keep it from tarnishing. See BRASS; DIPPING; STAINS FOR METALS; OREIDE.
Ormolu Dipping Acid for Sheet Brass.--Sulphuric acid 2 gallons, nitric acid 1 pint, muriatic acid 1 pint, water 1 pint, nitre 12 pounds. Put in the muriatic acid last, a little at a time, and stir with a stick. For cast brass: Sulphuric acid 1 quart, nitre 1 quart, water 1 quart; a little muriatic acid may be added or omitted. See DIPPING.