Scanning tunneling microscopy has been used to study the adsorption of atomic sulfur and 1,3-butanediol on silver films formed by evaporation onto Si(111)-(7X7) substrates. Thin silver films only a few monolayers thick grown on Si(111) show a square-root 3 X square-root 3 R30-degrees reconstruction, while thicker films show a hexagonal close-packed, unreconstructed Ag(111) surface. At high deposition rates, screw dislocations in die films are commonly observed. Atomic sulfur adsorbed on thin Ag films showing a square-root 3 X square-root 3 R30-degrees reconstruction appears as a protrusion when filled states are imaged and as a depression in empty state images. The sulfur atoms bond almost exclusively at lattice defects which appear to be vacancy clusters. 1,3-butanediol appears as a large depression at all biases, indicating that the adsorbate electrostatically repels charge and lowers the metal density of states around the adsorption site.