of 90% silver was unlimited legal tender together with gold, while 2-, 1,- and -franc coins of 83.5% silver were made subsidiary or limited legal tender. The billon coins (5% to 15% silver) were also subsidiary; they were replaced by Cupronickel and Nickel in 1879. In 1918/19, there was experimentation with brass (Cu-Zn) versions of the 5 and 10 centimes coins, but these were again retired in 1924. In 1968, the 83.5% silver coins were also replaced by Cupronickel, as the value of the silver in the alloy had exceeded its face value, and the silver coins were taken out of circulation in 1971. The 2 and 1 centime coins were taken out of circulation entirely in 1978 and 2007, respectively. The 5 centimes coin was switched to a yellow-metal (Aluminium bronze) alloy in 1981, and the white-metal (Cupronickel) 5 centimes coins of 1879–1980 were retired in 1984. The (magnetic) Nickel versions of the 20 centimes coin (1881–1938) were retired in 2004, leaving the 10 centimes coins of 1879 onwards as only 19th-century coins that remain in official circulation. Bronze coins 1 centime: bronze (1.2g), replaced with zinc (1.5g) in 1942; designed by Alexander Hutter; obv: federal coat of arms with liberty cap and the legend "HELVETIA", rev: numeral 1 in a wreath. Minted again in bronze in 1948 (1.5g); redesigned by Josef Tannheimer; obv: Swiss cross with legend "HELVETIA", rev: numeral 1 and an ear of corn. Taken out of circulation in 2007. 2 centimes: bronze (2.5g), replaced with zinc (2.4g) in 1942; designed by Alexander Hutter; obv: Swiss coat of arms with liberty cap and the legend "HELVETIA", rev: numeral 2 in a wreath. Minted again in bronze in 1948 (3.0g); redesigned by Josef Tannheimer, obv: Swiss cross with legend "HELVETIA", rev: numeral 2 and an ear of corn. Taken out of circulation in 1978. Billon coins 5 centimes: billon (5% silver, 1.67g); designed by Karl Friedrich Voigt; obv.: federal coat of arms with wheat ears and legend "HELVETIA", rev: numeral 5 in a wreath. Minted from 1879 in cupronickel (Cu-Ni, 2.0g); obv: head of Liberty (design by Karl Schwenzer), legend "CONFŒDERATIO HELVETICA". Minted in cupronickel from 1879-1980, except in 1918 (brass, Cu-Zn), 1932-1939 and 1941 (nickel). Minted in aluminium-bronze (Cu-Zn-Al) since 1981; all pre-1981 versions were taken out of circulation in 1984. 10 centimes: billon (10% silver, 2.5g); designed by Karl Friedrich Voigt; obv.: federal coat of