Arsenic and Old Bookcloth: Identification and Safer Use of Emerald Green Victorian-Era Cloth Case Bindings

ABSTRACT

Analysis of nineteenth-century, cloth-case publishers’ bindings at Winterthur Library revealed starch-coated bookcloth colored with the toxic pigment “emerald green” (copper acetoarsenite). While this pigment was widely used in Victorian home goods and apparel, its use specifically in bookcloth has not been formally explored. A survey of bookcloth pigments was conducted to identify which toxic elements may be present in bookcloth and to determine how many bindings were colored with emerald green. English-language books at Winterthur published between 1837 and 1900 were analyzed with x-ray fluorescence spectroscopy. When arsenic and copper were found together, Raman spectroscopy was used to confirm emerald green. The dataset was further expanded using The Library Company of Philadelphia’s significant holdings of cloth-case publishers’ bindings. Copper and arsenic were detected in 38 rare and circulating books in total. Based on this data, trends in emerald green bookcloth use include: consistently vivid green hue; stamped decoration; English and American imprints from 1840s to 1860s. Quantitative analysis revealed significant levels of arsenic in friable bookcloth colorant. Emerald green books in the Winterthur collection were rehoused in zip-top polyethylene bags with hazard labels and circulating books were moved into the access-controlled rare book collection.

RÉSUMÉ

L'analyse de reliures d'éditeurs à couvertures toiles du XIXe siècle à la bibliothèque de Winterthur a révélé la présence d'une toile à reliure enduite à l'amidon et colorée avec le pigment toxique “vert de Schweinfurt ” (acéto-arsénite de cuivre). Alors que ce pigment était largement utilisé pour la production de biens pour la maison et de vêtements de l'époque victorienne, son utilisation spécifique pour la toile à reliure n'a pas été formellement explorée. Une étude des pigments de toiles à reliure a été menée afin d'identifier quels éléments toxiques peuvent être présents dans les toiles à reliure et de déterminer combien de reliures ont été colorées avec du vert de Schweinfurt. Les livres en langue anglaise de Winterthur publiés entre 1837 et 1900 ont été analysés par spectroscopie de fluorescence X. Lorsque de l'arsenic et du cuivre ont été trouvés ensemble, la spectroscopie Raman a été utilisée pour confirmer la présence de vert de Schweinfurt. À l'ensemble de ces données ont été ajouté celles issues de l'importante collection de reliures d'éditeurs à couvertures toiles de la Library Company of Philadelphia. Au total, du cuivre et de l'arsenic ont été détectés dans 38 livres rares et en circulation. Les tendances qui se dégagent de l'ensemble des données sur l'usage des toiles à reliure vert de Schweinfurt comprennent : une teinte verte systématiquement vive, un décor estampé et des marques d'imprimeurs anglais et américains des années 1840 aux années 1860. Les analyses quantitatives ont révélé des taux significatifs d'arsenic dans le colorant de la toile à reliure friable. Les livres à vert de Schweinfurt de la collection de Winterthur ont été reconditionnés dans des sacs en polyéthylène avec fermeture à glissière à pression dotés d'étiquettes de danger et les livres en circulation ont été transférés dans la collection de livres rares à accès contrôlé. Traduit par Anne-Stéphanie Etienne.

RESUMO

A análise das amarras de encadernações dos editores do século XIX na Biblioteca Winterthur revelou um pano de livro revestido de amido colorido com o pigmento tóxico “verde esmeralda” (acetoarsenito de cobre). Embora este pigmento tenha sido amplamente utilizado em artigos e vestuário vitorianos, seu uso especificamente em bookcloth (revestimentos de livros com tecido) não foi formalmente explorado. Foi realizado um levantamento de pigmentos de pano de livro para identificar quais elementos tóxicos podem estar presentes em pano de livro e determinar quantas encadernações foram coloridas com verde esmeralda. Livros em língua inglesa em Winterthur publicados entre 1837 e 1900 foram analisados com espectroscopia de fluorescência de raios-X. Quando arsênico e cobre foram encontrados juntos, a espectroscopia de Raman foi usada para confirmar o verde esmeralda. O conjunto de dados foi expandido usando o significante acervo da Companhia de Bibliotecas da Filadélfia de editores de estojos de tecido. Cobre e arsênico foram detectados em 38 livros raros e circulantes no total. Com base nesses dados, as tendências no uso de pano de livro verde esmeralda incluem: tonalidade verde consistentemente vívida; decoração estampada; Impressões inglesas e americanas de 1840 a 1860. A análise quantitativa revelou níveis significativos de arsênico em corante friável em revestimentos de livros com tecido (bookcloth). Livros verdes esmeraldas da coleção Winterthur foram realojados em sacos de polietileno tipo zip-top com rótulos de perigo e livros circulantes foram movidos para a coleção de livros raros com acesso controlado. Traduzido por Beatriz Haspo.

RESUMEN

El análisis de las encuadernaciones en tela de las editoriales del Siglo XIX en la Biblioteca de Winterthur reveló una tela para encuadernaciones recubierta de almidón coloreada con el pigmento tóxico “verde esmeralda” (acetoarsenito de cobre). Si bien este pigmento se usó ampliamente en artículos para el hogar y prendas de vestir victorianas, su uso específico en telas para encuadernaciones no se ha explorado formalmente. Se realizó un estudio de los pigmentos de las telas para encuadernaciones para identificar qué elementos tóxicos pueden estar presentes en las telas para encuadernaciones y para determinar cuántas encuadernaciones estaban coloreadas con verde esmeralda. Los libros en inglés de Winterthur publicados entre 1837 y 1900 se analizaron con espectroscopía de fluorescencia de rayos X. Cuando se encontraron juntos arsénico y cobre, se usó la espectroscopia Raman para confirmar el verde esmeralda. El conjunto de datos se amplió aún más utilizando las importantes existencias de encuadernaciones comerciales de estuches de tela pertenecientes a The Library Company of Philadelphia. Se detectó cobre y arsénico en total en 38 libros raros y en circulación. Con base en estos datos, las tendencias en el uso de telas para encuadernaciones de color verde esmeralda incluyen: un tono verde consistentemente vivo; decoración estampada; impresiones inglesas y americanas de 1840 a 1860. El análisis cuantitativo reveló niveles significativos de arsénico en el colorante friable de telas para encuadernaciones. Los libros verde esmeralda de la colección Winterthur se reubicaron en bolsas de polietileno con cierre hermético con etiquetas de peligro y los libros en circulación se trasladaron a la colección de libros raros con acceso controlado. Traducción: Amparo Rueda.

KEYWORDS:

• Arsenic
• bookbinding
• bookcloth
• copper acetoarsenite
• green
• libraries
• Victorian

Acknowledgments

The authors thank former Winterthur Library Director Emily Guthrie and staff for their support of and contributions to this project; Winterthur interns Layla Huff, Sara Leonowitz, Meghan Abercrombie, Philip De Paola, and Esther Weyer for collecting and interpreting analytical data; and The Library Company of Philadelphia and Head of Conservation Jennifer Rosner for access to their collections for analysis. Special thanks to Suzy Morgan, Library Conservator at Arizona State University Library, for the suggestion to print color swatch bookmarks. The emerald green color swatch bookmarks were designed by Karissa Muratore (WUDPAC ‘20) using photography by Winterthur photographer Jim Schneck. The PLM protocol for identifying emerald green and chrome green bookcloths was created by Mina Porell, Winterthur Post-Graduate Fellow in Paintings Conservation. The authors thank Michael Gladle, Dr. Justin Brower, and Dr. David Goldsmith for discussing the merits and health/safety implications of the project. The authors gratefully acknowledge funding support from the ICON Fred Bearman Research Grant, the University of Delaware Art Conservation Department, the Winterthur Do More 24 Delaware campaign coordinated by the United Way, and individual donations.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1 There are many common names for arsenic-based green pigments, and these were often used interchangeably (and therefore inaccurately) by the contemporary public. Some historical sources also mistakenly conflate Scheele’s green (AsCuHO₃, copper (II) arsenite) with the various other names for emerald green (Cu(C₂H₃O₂)₂·3Cu(AsO₂)₂, copper (II) acetoarsenite), such as Schweinfurt green, Paris green, Vienna green, Mitis green and King’s green; however, Scheele’s green and emerald green are distinct compounds. Paris green was a commercial name commonly used when emerald green was sold as a pesticide. Emerald green was the name used to describe the compound copper acetoarsenite by the German chemists who first synthesized it, and these two terms will be used interchangeably here (FitzHugh 2019).

2 Elemental analysis was performed with a handheld Bruker Tracer III-SD XRF spectrometer using a rhodium tube (40 kV high voltage, 9.6μA anode current, 25μm Ti/305μm Al) for 30 s live time irradiation. A zero-background plate (design courtesy of Institute for the Preservation of Cultural Heritage, Yale University) was placed behind the cover to mask elements within the textblock. Spectra were interpreted using the PXRF1 software. When arsenic and copper were found together on Winterthur volumes with pXRF, Raman spectroscopy was used to confirm copper acetoarsenite (Figure 2). The books were analyzed with a Renishaw Invia Raman spectrometer (785 nm diode laser) in conjunction with WiRE 3.4 software with extended scan from 200 to 2200 cm⁻¹, 50X objective lens, exposure time of 15 s/scan for 3 accumulations, and 1% laser power.

3 To request a bookmark, please email postal address to [email protected] with “Emerald Green Bookmark” in the subject line. The Poison Book Project site on the Winterthur Wiki can be found at: http://wiki.winterthur.org/wiki/Poison_Book_Project.

Additional information

Notes on contributors

Melissa Tedone

Melissa Tedone holds a dual appointment as conservator and lab head for book and library materials at Winterthur Museum, Garden & Library, and affiliated associate professor in the Winterthur/University of Delaware Program in Art Conservation. She is a professional associate of the American Institute for Conservation (AIC), and founding co-chair, with Rosie Grayburn, of the Bibliotoxicology Working Group. She earned a PhD in Slavic literary history from Yale University, and an MSIS/CAS in library and archives conservation from the University of Texas at Austin. Address: Department of Conservation, Winterthur Museum, Garden and Library, Winterthur, DE 19735, USA. Email: [email protected]

Rosie Grayburn

Rosie Grayburn is currently scientist and head of the Scientific Research and Analysis laboratory at Winterthur Museum, and affiliated associate professor in the Department of Art Conservation, University of Delaware. She obtained a joint PhD in 2015 from the University of Warwick, United Kingdom, and Universiteit Gent, Belgium, where she conducted research into conservation treatments and corrosion processes using novel time-lapse analytical methodologies. From 2015 to 2017, she was the postdoctoral fellow in Conservation Science within the Treatment Studies research area at the Getty Conservation Institute.