Bimetallism is an economic system in which a country uses two metals, typically gold and silver, as the basis for its currency. The value of each metal is expressed in terms of a fixed weight, establishing a legally mandated exchange rate between the two. This dual-metal standard aims to provide greater stability and flexibility in the monetary system. Historically, bimetallism has had both advocates and critics. Proponents argue that it offers a more stable and diverse monetary base, as it can help mitigate fluctuations in the value of one metal by allowing the other to act as a counterbalance. Additionally, it is believed to promote international trade by providing a broader range of currencies for use in transactions. However, critics argue that bimetallism can be inherently unstable due to the potential for fluctuations in the market value of the two metals. When the market ratio between gold and silver diverges from the legally established ratio, a phenomenon known as Gresham's Law may come into play. This law states that "bad money drives out good money," meaning that people will hoard the undervalued metal and use the overvalued metal for transactions. This can lead to a scarcity of one metal, causing imbalances in the monetary system and potentially destabilizing the economy. Bimetallism was most prominent in the 19th century, when countries like the United States and France adopted the system. However, it largely fell out of favor by the early 20th century, as countries transitioned to the [[gold standard]] or later to [[fiat currency]] systems, which do not rely on a physical commodity to back their value.