On Thursday, April 9, Dr. Jennifer Mass, senior scientist, Conservation Research Laboratory, Winterthur Museum, served as guest lecturer in the the Mellon-supported interdisciplinary seminar ARTH 4605/6605: Art|Science Intersections: More than Meets the Eye, offered jointly by Dr. Andrew Weislogel, Askin curator of Earlier European and American Art at the Johnson Museum and Professor Lisa Pincus of the History of Art and Visual Studies. Core Cornell presenters for the course have included Professor C. Richard Johnson of the School of Electrical and Computer Engineering, Dr. Arthur Woll of the Cornell High Energy Synchrotron Source (CHESS), and Professor Sturt Manning of CIAMS.
The loan of LOL’s handheld X-ray fluorescence spectrometer allowed Dr. Mass to demonstrate to students the process of distinguishing elements in historic pigments in the Museum’s School of Rembrandt Still Life with Dead Game painting, which had been the subject of prior investigations including x-ray fluorescence mapping at CHESS and microscopy of cross-section samples previously taken by Dr. Mass. In class the students were able to witness the XRF spectrometer detect mercury in the crest of one of the ducks’ heads, which indicates a bright vermilion red pigment that has since darkened to brown. The XRF device also detected cobalt, a key element in the 17th century pigment smalt, which is made from ground cobalt blue glass. This pigment also darkens to grey-brown over time. These real-time demonstrations were crucial for the students’ realization that the colors we see in historic paintings are often much different from what the original artists intended. Dr. Mass expertly guided the class in the demonstration, showing setup of the device and use of the software to distinguish between elements desired for the experiment and those of lesser interest that commonly occur.