Author: Kimberly Kenyon, Senior Conservator
While our conservation lab was primarily established for the purpose of conserving artifacts from the shipwreck of Queen Anne’s Revenge/La Concorde, we have been able to expand our capabilities through the years to offer occasional assistance with different projects. We always look forward to new challenges and ways in which we can apply our knowledge of conservation, analytical techniques, and materials to help solve riddles with our colleagues in other disciplines.
Recently, Larry Houston, book and paper conservator for East Carolina University’s Joyner Library, contacted us with an interesting research question. Joyner acquired a set of books dating to the mid-nineteenth century which were suspected to contain a pigment in the binding called Paris green, or copper acetoarsenite. This compound, a vibrant emerald green, was used in bookbinding as a colorant, favored by artists as a paint, and even as the trendiest color in Victorian fashion. It was additionally found to be an effective insecticide, due to the high toxicity of arsenic in the compound.
In 2019, conservators and scientists at Winterthur/University of Delaware Program in Art Conservation began an investigation of books suspected to have been bound in cloth dyed with Paris green. The Poison Book Project has now identified 35 individual titles verified to contain arsenic, all printed either in the UK or the US in the mid-nineteenth century. The Project notes that not every copy of each title would have been identically bound, so it is possible that a specific copy may lack arsenic completely. With four of Joyner’s new acquisitions appearing on the list of known culprits, however, Larry wanted to be certain, before these books were put into the hands of library patrons.
Through elemental analysis using x-ray fluorescence spectrometry, we were able to take a closer look at the books. Five books were tested, including one French-language book, which would have been the first documented non-English title to contain arsenic, if positive. However, upon analysis of the results, it was revealed that only three of these suspected titles, Leaflets of Memory (1854), The Oasis (1854), and Plants of the Holy Land (1861), tested positive for arsenic. Armed with this knowledge, these books will be specially housed to protect patrons and placed inside the rare book vault under restricted access, to keep handling and risk of exposure to a minimum.
So, the next time you find yourself in a thrift store looking at those old books that would look amazing as colorful décor, you might think twice about that bright green one…
-Lipscher, J. “Emerald Green,” ColourLex. Accessed September 4, 2020. https://colourlex.com/project/emerald-green/
-Tedone, M. “Poison Book Project.” Accessed September 4, 2020. http://wiki.winterthur.org/wiki/Poison_Book_Project
-Front cover of Plants of the Holy Land, with distinct Paris green cover. Image by NC Department of Natural and Cultural Resources.
-QAR Assistant Conservator Elise Carroll (left) and Senior Conservator Kim Kenyon (right) analyzing a book for arsenic using XRF. Image by NC Department of Natural and Cultural Resources.