Hillsdale Whig Standard

Process of Coining Gold.

The miners have to grind the gold rock fine—keeping it wet constantly, and as it becomes fine, it is washed off. They have a hard kind of stone for grinding.—They then mix quicksilver with it, and that collects the gold dust. It is washed out, dried, and goes through some kind of beating process. The gold dust is then usually sold to the superintendent of the mint. To find the value each parcel has to be assayed. The assaying is the most curious and scientific of all the business of the mint. The melters take the gold dust, melt it, and cast it into bars, when it is weighed accurately and a piece cut off for the assayer. He takes it, melts it with twice its weight in silver in connection with several times its weight of lead. It is melted in some small cups made of bone-ashes, which absorb all the lead. When a larger part of the silver is extracted by another process, and the sample is then rolled out to a thin shaving, coiled up and put in a sort of glass phial called a matrass along with some nitric acid. The matrasses are put on a furnace, and the acid boiled some time, poured off, a new supply put in, and boiled again. This is done several times, till the acid has extracted all the silver and other mineral substances, leaving the sample pure gold. The sample is then weighed, and by the difference between the weight before assaying and after, the true value is formed. The gold after it has been assayed, is melted and refined, and being mixed with due proportion of alloy (equal parts of silver and copper) is drawn into long strips, in shape not unlike an iron hoop for casks; the round pieces are cut out with a sort of punch, each piece weighed and brought to the right size by a file, if too heavy, when it is milled, or the edge raised and put into a stamping press, whence it comes forth a perfect coin bearing the endorsement of "U. S."