Poison Book Project

This page provides information about the Winterthur Poison Book Project, an investigation initiated in April 2019 to identify potentially toxic pigments coloring Victorian-era bookcloth.

Analysis of decorated, cloth-case, publisher’s bindings at Winterthur Library revealed starch-coated bookcloth colored with “emerald green,” or copper acetoarsenite, an inorganic pigment known to be extremely toxic. This pigment’s popularity in England and the United States during the Victorian era is well documented. While the colorant was known to be widely used in textiles for home decoration and apparel, wallpaper, and toys, its use specifically in bookcloth has not been formally explored. Successful bookcloths were a closely guarded trade secret during the nineteenth century, limiting our current understanding of their materiality and manufacture. Conservation staff and interns at Winterthur Museum, Garden and Library conducted a survey of bookcloth pigments in order to correlate the presence of emerald green and other potentially toxic pigments with specific publishers and date ranges. The project initially focused on the library’s circulating collection, which poses a greater potential risk to patrons, and then expanded to include the rare book collection.

In December 2019, the Winterthur Library data set was further expanded in cooperation with The Library Company of Philadelphia, which has significant holdings of cloth-case publisher’s bindings.

General Handling Tips for Nineteenth-Century Cloth-Case Bindings

Nearly 40% of the nineteenth-century cloth-case bindings analyzed for this project, to date, contained lead in the bookcloth colorant. No matter what pigments or dyes may be present, it is best practice to wash hands after handling books, especially before eating or drinking.

Methodology

English-language books published between 1837 and 1900 align with the rising use of bookcloth on publisher’s case bindings, and were identified at Winterthur Library through the WinterCat OPAC. The first two hundred books tested represented a range of vivid bookcloth colors. Thereafter, only books covered in green cloth were selected for analysis, in order to focus on arsenic and move through the collection more efficiently. X-ray fluorescence (XRF) was used to collect elemental information from bookcloths. When arsenic and copper were found together, Raman spectroscopy was used to confirm copper acetoarsenite.

The Library Company of Philadelphia shelves its Americana collection chronologically according to imprint date. Volumes were selected for testing by visual scan of the shelves in the appropriate date range (1830s through 1900). Approximately eighty books bound in green bookcloth or with green paper onlays were tested using handheld XRF. Spectra and bibliographical data were saved for each volume which showed the presence of arsenic and copper.

The University of Delaware Soil Testing Lab performed quantitative analysis on a destructive sample from one Winterthur Library volume and revealed the presence of significant levels of arsenic. Furthermore, quantitative analysis for arsenic on a dry cotton swab rolled across the surface of the bookcloth indicated that the bookcloth colorant is extremely friable.

Project Researchers

Lead Conservator: Dr. Melissa Tedone

Lead Scientist: Dr. Rosie Grayburn

Contributors:

Emily Guthrie, Winterthur Library Director and NEH Librarian for Printed Books & Periodicals

Jennifer Rosner, Head of Conservation, The Library Company of Philadelphia

Meghan Abercrombie, Winterthur Intern

Philip DePaola, Winterthur Intern

Layla Huff, Winterthur Intern

Sara Leonowitz, Winterthur Intern

Disclaimer

Copyright 2024. This article describes conservation procedures and is meant to be used as exchange of technical information among trained cultural heritage conservators, and the procedures described herein should not be performed by anyone who is not a trained professional. Further, any advice, graphics, images, and information contained in this page is presented for general educational and information purposes, and to increase safety awareness in connection with the storage and handling of aged books that may contain toxic chemicals, such as arsenic. The storage, handling, and other safety tips included in this page are suggestions only and have been collected by the Poison Book Project of The Henry Francis du Pont Winterthur Museum, Inc. after consultation with scientists and other experts in the conservation field. None of the content in this page has been subjected to a formal peer review and is not intended to be medical or other expert advice or services, and should not be used in place of consultation with appropriate professionals. The information contained in this page should not be considered exhaustive, and the user should seek the advice of appropriate professionals.

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