Abigail Quandt: Preserving the Brain in the Box: the Scientific Analysis and Conservation Treatment of the Archimedes Palimpsest

For the past twelve years an extremely rare and unusual medieval parchment manuscript known as the Archimedes Palimpsest has been the subject of an international project based at the Walters Art Museum in Baltimore. The goals of the project were to disbind and stabilize the leaves of the codex, and to image and transcribe the palimpsested texts. A presentation given at the Care and Conservation meeting in 2003, when the project was still in its infancy, provided preliminary information about the coordinated efforts of conservation, imaging and transcription, and the results that had been achieved to date. After the imaging work was completed in 2007 the condition of the ninety original manuscript leaves, which included seven different Greek texts dating to the 10th-11th centuries, was thoroughly assessed. The parchment and inks of these seven texts were characterized and the process used by the 13th c. Greek scribe to make the palimpsest was documented. To better understand the relatively recent deterioration of the parchment caused by microorganisms, microscopic samples taken from selected folios were analyzed at the Istituto Centrale per il Restauro e la Conservazione del Patrimonio Archivistico e Librario in Rome. Two species of bacteria and fungi were tentatively identified by SEM, and a purple pigment produced by the bacteria was also characterized. These investigations served to inform the final treatment of the ninety folios, which was undertaken by a conservation team lead by the author and based at the Walters Art Museum.

For this work several new techniques were developed and will be described in detail in the presentation. Both layers of iron gall ink exhibited extensive corrosion as well active flaking, and this was consolidated with a dilute solution of gelatin applied as an ultrasonic mist. Mending of edge splits and tears was carried out with toned remoistenable tissues, while mending over text areas was done with an alcohol-activated repair paper made with Berlin tissue. Most challenging of all was the stabilization and repair of leaves severely degraded by bacteria and fungi. Parchment leaf casting was not an option in this case, as the use of an aqueous system for repair would cause irreversible damage and the thin remnants of erased text on both sides of the folios could easily be obscured by pulp. A technique was thus developed to internally strengthen the parchment by both spray and brush application of Klucel-M in alcohol. This was followed by the limited mending of splits and losses using a remoistenable Berlin tissue. As the original manuscript leaves were to remain separate a new method of matting and framing was devised to permit double-sided viewing, yet would also protect and preserve the fragile leaves for the long term. A novel method of mounting a small number of the most degraded leaves was developed to ensure that they would be adequately supported and not under strain, yet easily viewed on both sides. In this technique the leaves were encapsulated inside a pocket made of reinforced Berlin tissue, which was then secured into the double-sided mat with a false margin of Japanese tissue on both sides.

The analysis and conservation of the Archimedes Palimpsest has been fully described and illustrated in a two volume catalogue of the project, which was published by Cambridge University Press in the fall of 2011. However, due to its high cost and limited circulation, few conservators will have access to this publication. With this in mind I would like the opportunity to present the information, much of which is new since 2003, to an audience of practicing conservators and manuscript specialists at the Care and Conservation meeting in Copenhagen this coming October.