NOVELTY - The method comprises reducing a first reducible metal ion of a composition to a first metal, and co-producing nitric oxide at a ratio (A) of moles nitric oxide co-produced per mole of the first reducible metal ion. The composition comprises a second metal or metal ion that comprises lanthanide metal or ion of lanthanide and differs in atomic number from the first reducible metal ion. The ratio A is less than 15% of a ratio B, where B is the maximum instantaneous ratio of moles nitric oxide co-produced per mole of the first reducible metal ion.    USE - The method is useful for producing a first metal, which is useful in a metal nanowire such as a silver nanowire and in an article including an electronic display, a touch screen, a portable telephone, a cellular telephone, a computer display, a laptop computer, a tablet computer, a point-of-purchase kiosk, a music player, a television, an electronic game, an electronic book reader, a transparent electrode, a solar cell, a light emitting diode, an electronic device, a medical imaging device and/or a medical imaging medium (all claimed).    ADVANTAGE - The method is capable of producing the first metal with high purity and improved yield.    DETAILED DESCRIPTION - The method comprises reducing a first reducible metal ion of a composition to a first metal, and co-producing nitric oxide at a ratio (A) of moles nitric oxide co-produced per mole of the first reducible metal ion. The composition comprises a second metal or metal ion that comprises lanthanide metal or ion of lanthanide and differs in atomic number from the first reducible metal ion. The ratio A is less than 15% of a ratio B, where B is the maximum instantaneous ratio of moles nitric oxide co-produced per mole of the first reducible metal ion when reducing the first reducible metal ion in the presence of copper ions (Cu2+). The ratio A is less than 40% of a ratio B, where B is the maximum instantaneous ratio of moles nitric oxide co-produced per mole of the first reducible metal ion when reducing the first reducible metal ion in the presence of iron ions (Fe2+). The ratio A is less than 10% of a ratio B, where B is the maximum instantaneous ratio of moles nitric oxide co-produced per mole of the first reducible metal ion when reducing the first reducible metal ion in the presence of tin ions (Sn2+). The ratio A is less than 10% of a ratio B, where B is the maximum instantaneous ratio of moles nitric oxide co-produced per mole of the first reducible metal ion when reducing the first reducible metal ion in the presence of manganese ions (Mn2+). The ratio A is less than 15% of a ratio B, where B is the maximum instantaneous ratio of moles nitric oxide co-produced per mole of the first reducible metal ion reduced when reducing the first reducible metal ion in the presence of chromium ions (Cr3+). INDEPENDENT CLAIMS are included for:    (1) a metal nanowire; and    (2) a method of preparing nanostructures.    DESCRIPTION OF DRAWING(S) - The diagram shows an optical micrographic image of a silver nanowire.