The Secret Method and the State: Official Attitudes Towards Wet Copper Production in Song China

As base material for the production of cash coins, copper was the most impor tant metal in the Chinese monetary system, and hence for the political economy of China, at least until the dawn of the silver age in the sixteenth century. During the Northern Song period, what Mark Elvin deemed a “med­ ieval economic revolution” manifested itself in such phenomena as a more diverse division of labor, commercialization, and urbanization, along with the increased use of monetary transactions instead of barter.1 This development was supported by a boom in copper production, which was tightly controlled by the state and employed as coinage to meet the aims of its monetary policy.2 When ore deposits began to be exhausted and production costs increased, the diminishing output of copper developed into a risk for the currency system