What is Ansei Ichibugin?
The Ansei Ichibugin (安政一分銀) is a counted silver coin with a face value of one bu, issued by the Edo shogunate beginning in August 1859 (Ansei 6). According to the permanent exhibition catalog of the Currency Museum (page on the opening of the ports and the outflow of gold coins), the Ansei Ichibugin is noted as being issued in August 1859 with a fineness of 87% (catalog). The same chart lists the Tenpō Ichibugin (天保一分銀) (1837, fineness 99%) and the Ansei Nishugin (安政二朱銀) (1859, fineness 85%) (catalog). The chart of official rates in the permanent exhibition catalog states that one ryō in gold coins equals four bu, which is equivalent to sixteen shu. One ryō corresponds to four Ichibugin coins (catalog). This entry includes only what is recorded in the consulted materials. Details such as weight, dimensions, minting volume, current numbers, and distinctions based on script or marks are not confirmed within the scope of the materials. Updates will be added with sources to the Complete Record of Ansei Ichibugin as they are confirmed.
Background of Issuance (Catalog 'Opening of the Ports and Gold Coin Outflow' / History of Japanese Currency)
According to the Currency Museum's 'History of Japanese Currency', foreign silver coins used in trade were mainly Mexican silver coins that entered Japan. Under the Treaty of Peace and Amity between the United States and Japan (1854), it was decided that one dollar in foreign silver was equivalent to one Ichibugin, but later, the first U.S. Consul General to Japan, Harris, pushed for 'the principle of equal kind and quantity,' leading to one dollar in foreign silver being equivalent to three Ichibugin (Currency Museum 'History of Japanese Currency'). The same 'History of Japanese Currency' notes that in 1859, concerned about the outflow of gold coins due to the opening of the ports, the shogunate issued the Ansei Nishugin, which contained more pure silver than the Tenpō Ichibugin, on the day before the port opened and attempted to exchange one dollar in foreign silver for two Ansei Nishugin. However, due to American opposition, one dollar in foreign silver became equivalent to three Ichibugin (Currency Museum 'History of Japanese Currency'). The permanent exhibition catalog records that to prevent the outflow of gold coins, the shogunate issued the Ansei Nishugin just before the opening of the ports, with the amount of silver in two Nishugin (1 bu) being almost the same as one foreign silver coin (1 dollar). It also notes that due to protests from Western countries that 'the value of foreign silver in Japan will decrease,' the shogunate halted the issuance of Ansei Nishugin and instead melted down foreign silver to mint Ansei Ichibugin for foreign silver exchange purposes (catalog).
Outflow of Gold Coins and the Man'en Recoinage (History of Japanese Currency / Catalog)
The Currency Museum's 'History of Japanese Currency' notes that at the time, the price of gold and silver was gold 1g ≒ silver 5g in Japan and gold 1g ≒ silver 15g abroad, making gold relatively cheaper in Japan. As a result, a large amount of gold coins flowed overseas. Foreign merchants exchanged four foreign silver coins at the rate of one Ichibugin, converting them further into koban in Japan, and could obtain twelve foreign silver coins when exchanged overseas (Currency Museum 'History of Japanese Currency'). In 1860, the Man'en era (1860) recoinage reduced the pure gold content to one-third, aligning the gold-silver ratio with international standards, which stemmed the massive outflow of gold coins overseas (Currency Museum 'History of Japanese Currency'). The permanent exhibition catalog also states that due to the Man'en era recoinage (1860), the weight of the gold coins was reduced to one-third of the previous amount, aligning the domestic gold-silver ratio almost with overseas levels, leading to the end of the gold coin outflow (catalog).
Record of Fineness and Relation to Tenpō Ichibugin (within the scope of materials)
In the chart of the permanent exhibition catalog of the Currency Museum, Tenpō Ichibugin is noted as being from 1837 with a fineness of 99%, and Ansei Ichibugin from 1859 with a fineness of 87% (catalog). The fineness indicated in the catalog is rounded values. 'History of Japanese Currency' states that the Ansei Nishugin contained more pure silver than the Tenpō Ichibugin, but there is no description of a comparison between the weight or pure silver content of the Ansei Ichibugin and the Tenpō Ichibugin in the consulted materials. Because there is no description of individual clues for distinguishing them (writing style, marks, weight, dimensions) in the consulted materials, this entry does not cover them. When verifying individuals, it is essential to cross-reference with the catalog's description and not conclude based on one characteristic.
Materials and Records
The basis for this entry lies in the permanent exhibition catalog of the Currency Museum of the Bank of Japan Financial Research Institute (pages on the opening of the ports and the outflow of gold coins/the exchange shops and the market rate of gold, silver, and coins) and the same museum's 'History of Japanese Currency' (Modern Chapter). There are no recorded auction results confirmed as Ansei Ichibugin yet. Similar types' market values are not presented as prices for this coin type. Organization with sources is available in Complete Record of Ansei Ichibugin. Related entries: Tenpō Ichibugin • Ichibugin • Introduction to Edo Silver Coins (Chogin, Mameita Gin).