淸代乾隆中葉における雲南辦銅の空閒的再編

Abstract

During the Qianlong era of the Qing dynasty, imperial copper coins 制錢 were chiefly minted from Yunnan copper. Yunnan provincial authorities supplied copper received from private producers to the Beijing Mints 京局, several other provinces, and their own mints (a process termed Yunnan copper procurement 雲南辦銅 in this paper). At first, copper was secured mostly from the Tangdan 湯丹 and surrounding mines in eastern Yunnan, but in the mid-Qianlong era, it shifted to a two-pillar system with the Ningtai 寧臺 mine in western Yunnan also employed. This paper clarifies the policy-making process of this spatial reorganization of Yunnan copper procurement. Beijing Mints, the main consumer of Yunnan copper, used the highest grade of copper, called xieketong 蟹殻銅. Although production from the Tangdan mines had been declining since the end of first decade of the Qianlong era due to rising production costs, the Ministry of Revenue insisted that Yunnan deliver only xieke copper. While it occasionally approved the delivery of the second highest grade of copper known as bantong 板銅, it refused to officially adopt it. Yunnan responded by developing new mines located mainly in central Yunnan, and by increasing the price paid to the Tangdan mines and other mines important at the time based on the marginal profit from the expansion of coinage minting in the province. Copper fromthe Ningtai mine, whose production increased rapidly from the end of the third decade of the Qianlong era, was of low grade and was therefore regarded as suitable only for minting the province's own coins. However, in Qianlong 42, Yunnan faced a sharp decline in copper production and serious delays in copper deliveries to the Beijing Mints. In response, they switched more than half of the copper produced at the Tangdan mines to bantong copper, thereby lowering the production costs by eliminating the process of refining it into xieke copper. At the same time, they minimized the reduction in xieke copper deliveries to Beijing Mints by refining lowgrade copper from the Ningtai mine into xieke copper. The spatial reorganization of Yunnan copper procurement thus developed piecemeal through the interrelationship between the Ministry of Revenue and Yunnan province and was not the result of a decision made under a unitary policy enacted by a notionally unified entity called the “government.” In addition, Yunnan province's struggles to deliver Yunnan copper to Beijing Mints, which they had once led in order to profit themselves, marked a significant turning point in thelong-term transition of Yunnan copper procurement and production.