江戸時代における貨幣単位と重量単位 : 大黒作右衛門の「匁」の名目化=貨幣単位化意図を事例に

抄録

In the early modern period, debasement of the coinage was a significant way of re-establishing national finances, and one important way of doing so was to give the units used to weigh coins a face value. Both the ryo and the pound, for example, started out as weight units but turned into units of currency. This article shows how Daikoku Saku'uemon, a Bakufu-authorized coin maker, proposed to make the monme, a weight unit for silver, into a monetary unit in the Bunsei period (1818-30). The silver coins which Daikoku proposeed during the Bunsei period were the 43monme silver coin, for use in gift-giving, and the 50-me silver coin, for commercial use. Despite their nominal values, both were to weigh only 16 monme. This scheme is thought to have originated in the Bunka period (1804-18), but has also been detected in the Tempo period (1830-44). It would therefore seem that Daikoku had been making prorosals to the kanjosho (Ministry of Finance) for more than twenty years. The scheme proposed in the Tempo period was to involve not only a silver coin of high denomination, like the 43 monme or the 50-me, but also one of low denomination, such as a 2.5-monme or a 5-monme unit. In other words, Daikoku planned further debasement of the coinage even after the Bunsei debasement, through a radical nominalisation of the monme. Daikoku's proposals were made in an attempt to win back the recoinage responsibilities which he had lost after taking a negative attitude towards the recoinage plans of the Meiwa period (1764-72). However, the proposals were rejected by the kanjosho, probably because it was feared that usage of silver coins would grow even more complex.