Artificial Gold
2 of the 7 encyclopedias on this shelf carry an entry for Artificial Gold. Both are reproduced below, so you can see where they agree and where they differ.
American Watchmaker and Jeweler (1892)
A metallic alloy, at present very extensively used in France as a substitute for gold is composed of: Pure copper, 100 parts; zinc, or preferably tin, 17 parts; magnesia, 6 parts; sal-ammoniac 3 to 6 parts; quicklime, 1/8 part; tartar of commerce, 9 parts, are mixed as follows: The copper is first melted, and the magnesia, sal-ammoniac, lime and tartar are then added separately and by degrees, in the form of powder; the whole is now briskly stirred for about one-half hour, so as to mix thoroughly, and then the zinc is added in small grains by throwing it on the surface and stirring until it is entirely fused; the crucible is then covered and fusion is maintained for about 35 minutes. The surface is then skimmed and the alloy ready for coating. It has a fine grain, is malleable, and takes a splendid polish. It does not corrode readily, and is an excellent substitute for gold for many purposes. When tarnished, its brilliancy can be restored by a little acidulated water. If tin be employed instead of zinc, the alloy will be more brilliant.
The Encyclopedia of Founding (1892)
A French substitute for gold is made as follows: Melt copper, 100; then add separately and by degrees, in powder, magnesia 6; sal-ammoniac 4 1/2; quick-lime 1/8; tartar 9; and stir half an hour--after which add zinc, or, preferably, tin 17. Mix well, and continue the fusing for 35 minutes, with the crucible well covered before casting. This alloy does not corrode easily; when it does tarnish its former brilliancy can be restored by dipping in acid solution. See GOLD ALLOYS.