Linear sweep voltammetry has been used to examine Au(111) electrodes in 50 muM KCN solutions with pH's varying between 1 and 11. In situ scanning tunneling microscopy (STM) was employed to probe the adsorption of cyanide species and the dissolution/deposition processes of gold in pH 11, 0.1 M KF, and 0.1 M HClO4 solutions containing 50 muM KCN. Dissolution of gold commenced at a potential as negative as -0.8 V (vs SCE) in alkaline KCN solutions. Both in situ STM and voltammetry indicate that dissolution and deposition of gold were electrochemically reversible. STM atomic resolution yielded a reconstructed Au(111) surface rather than the cyanide adlattices, while etching proceeded at -0.8 V in an alkaline KCN solution. The dissolution of gold at -0.8 V in pH 11 KCN solution was highly selective and anisotropic, manifesting through step retreat in directions perpendicular to the herringbone features of the reconstructed Au(111) surface, or the [110] direction. Nearly all gold atoms on step ledges resided at unfaulted face-center cubic (fee) sites. In contrast, a number of cyanide adlattices were observed on Au(111) in acidic KCN, including a (6 x 6) structure on the reconstructed Au(111) at 0.1 V (vs SCE), followed by a phase transition to give (root7 x root7)R 19.1degrees and (root7 x root21)oblique structures on the unreconstructed Au(111) within the potential region of 0.2 and 0.3 V. Two intertwined ordered structures, (3 x 2root3)rect and (2 x 2), appeared at potentials more positive than 0.3 V, before dissolution of gold became apparent at 0.4 V.