This section is from the book "The Tinman's Manual And Builder's And Mechanic's Handbook", by Isaac Ridler Butt. Also available from Amazon: The Tinman's Manual And Builder's And Mechanic's Handbook.
This is a new metallic alloy which is now very extensively used in Prance as a substitute for gold. Pure copper 100 parts, zinc, or preferably tin 17 parts, magnesia 6 parts, sal ammoniac 3.6 parts, quick lime 1.8 parts, tartar of commerce 9 parts, are mixed as follows: The copper is first melted, then 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 half an hour, so as to mix thoroughly; and then the zinc is added in small grains by throwing it on the surface and stirring till it is entirely fused; the crucible is then covered and the fusion maintained for about 35 minutes. The surface is then skimmed and the alloy is ready for casting.
It has a fine grain, is malleable and takes a splendid polish. It does not corrode readily, and for many purposes is an excellent substitute for gold. 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. It is very much used in France, and must ultimately attain equal popularity here.