Project description:Multiple analytical techniques were used to characterize materials from the surfaces of two African sculptures in the collection of the Art Institute of Chicago: a Bamana power object (boli), and a Yoruba wooden sculpture of a female figure. Surface accretions on objects such as these have received relatively little scientific attention to elucidate their composition and function, in part because they are made with complex mixtures of natural materials, which are often unfamiliar and poorly represented in the scientific literature on artists’ materials. Mass spectrometry-based proteomics provided new insights on proteinaceous components, allowing us to identify the presence of sacrificial blood, and more specifically, blood from chicken, goat, sheep and dog. This new scientific evidence supports and supplements knowledge derived from curatorial and field work studies, and opens new doors to understanding the objects’ significance and history of use.