High Quality Content by WIKIPEDIA articles! In economics, bimetallism is a monetary standard in which the value of the monetary unit is defined as equivalent both to a certain quantity of gold and to a certain quantity of silver; such a system establishes a fixed rate of exchange between the two metals. In 1787 the United States Constitution established gold and silver as the legal tender of the United States at a floating exchange rate. Then in 1792, Alexander proposed fixing the silver to gold exchange rate at 15:1, as well as establishing the mint for the public services of free coinage and currency regulation "in order not to abridge the quantity of circulating medium.". With its acceptance, Sec.11 of the Coinage Act of 1792 established: "That the proportional value of gold to silver in all coins which shall by law be current as money within the United States, shall be as fifteen to one, proportional value of gold to silver. according to quantity in weight, of pure gold or pure silver;" the proportion had slipped by 1834 to sixteen to one. Bimetallism was effectively abandoned by the Coinage Act of 1873, but not formally outlawed as legal currency until the early 1900s. The merits of the system were the subject of debate in the late 19th century. If the market forces of supply and demand for either metal caused its bullion value to exceed its nominal currency value, it tends to disappear from circulation by hoarding or melting down.