Copper samples removed for assessment were obtained from the Atlases located under the Golden Sphere of La Fortuna. These samples as well as extracted corrosion products were examined employing an emission spectrograph, infrared spectrograph, infrared spectrophotometers and X-ray diffraction apparatus. Comparisons of constituent elements in the base metal and the intact corrosion sample revealed that the quantity of copper, magnesium, tin, nickel, lead and aluminum did not change. Silver was more adundant in the base metal than in the sample while the reverse was true of iron. Silicon in the corrosion sample greatly exceeded the amount found in the base metal. Two visually different corrosion types were removed and examined spectrophotometrically. Absorption peaks at 2.89, 6.40, 7.33, 7.57, 12.19, 20.00 and 28.30 mu compared favorably with similar peaks observed from Cu¹¹ oxalate obtained in previous organic acid-missle corrosion work. Copper oxalate was produced in the laboratory stoichiometrically and was determined to exhibit the same absorption spectra. Copper oxalate formed 50^-percent of the black corrosion product while the white corrosion product contained much less Cu¹¹ oxalate and a greater complexity of compounds including nitrate. A succession of events in copper corrosion is summarized and the possible importance of the biotic environment is suggested. The need for additional observations on biologically induced corrosion of copper is emphasized and it is necessary to evaluate the sequence of changes that have thus far received little recognition.