Verdigris: Taking copper patina from the Roman dung pile to the modern chemistry lab

CHED 36

Deberah M. Simon, simondm@whitman.edu, Department of Chemistry, Whitman College, 345 Boyer Avenue, Walla Walla, WA 99362
Sculptors and metalsmiths have always relied on the protective and aesthetic powers of the controlled corrosion of copper, but often with little understanding of the chemistry involved. A laboratory experience was developed which explored procedures ranging from the ancient method of burying copper in a pile of horse dung, through recipes used by modern sculptors, to a systematic approach in a laboratory setting. Because this class on the chemistry of art was developed specifically for non-science majors, emphasis was placed on developing a logical, testable method. In order to give context to the topic, each student produced a small copper artwork and applied a patina. The resulting pieces were displayed at a “Chemistry of Art” gallery show for the college.