Person:

Bulat, Elena

The first appearance of photographs in class albums at Harvard University occurred in 1852, beginning a tradition that has continued to the present day. The albums include photographic portraits of the graduating college classes, faculty, and staff as well as views of the campus. The class photographers, including John Adams Whipple, James Wallace Black, and George Kendall Warren, created salted paper prints for the albums from 1852 until 1864. The collection of early class albums was recently surveyed, as part of a larger initiative undertaken by Harvard Library’s the Weissman Preservation Center to preserve and enhance access to salt prints throughout the University. The albums have provided in many respects an ideal case history of the evolution of the new medium as they illustrate year by year how photographers perfected the salt print process and produced clearer, sharper images with greater definition and tonal range. The survey has allowed for the characterization of a large body of prints that has led to a more nuanced understanding of the underpinnings and evolution of this seminal photographic process.

Cultural heritage objects present a special set of challenges to analyze chemically. Often micro-sampling or even contacting the object is not appropriate or deemed too risky for fragile surfaces. Fourier Transform Infrared (FTIR) spectroscopy is a commonly used analytical technique for organic compound identification, either in a micro-sampling or Attenuated Total Reflection (ATR) mode, both of which inherently require some measure of contact with the sample. Presented here is a case study of the use of specular reflection FTIR spectroscopy, an FTIR collection mode that allows positive chemical identifications in a non-sampling and non-contact way. Although this paper focuses on the case study of coatings on 19th century photographs, the specular reflection FTIR mode is applicable to surface coatings on any artifact where molecular composition identification is needed but micro-sampling or physical contact with the sample have been ruled out. The main limitation of the specular reflection mode has traditionally been the lack of specular reflection FTIR reference libraries. As a result, the analytical project presented here first required generation of a specular reflection FTIR spectral library for historical coating materials used on 19th century prints by creating modern reference samples. The project is a result of collaboration between conservators at the Weissman Preservation Center at Harvard Library and materials scientists at Harvard’s Center for Nanoscale Systems to analyze original coatings on 19th century salted paper photographs in the collection of the Harvard University Archives.