A September 20, 2017 (Vol. 31, Issue 76) posting on the Conservation Distlist by Jean Holland, Senior Conservator Books, State Library Victoria in Melbourne, Australia contained a very strange inquiry, which reads as the following:
The Conservation Department at the State Library Victoria, with the assistance of University of Melbourne Conservation student Cancy Chu, are currently researching a first edition copy of Johannes Kepler’s Astronomia Nova, published in 1609. The paper in the book is in extremely poor condition, showing discolouration, softening and severe fracturing throughout the volume. >From a cursory survey, digitised copies of the book in other libraries do not show the same degree of paper deterioration, although they share the brown discolouration in some sections.
We are curious to know if our colleagues have seen examples of severe paper fragmentation in paper of this period, or in other copies of the Astronomia Nova. We also conjecture that the paper may have been given a historic treatment in the past, such as bleaching, which may be a factor in causing the fragmentation of the paper. We are wondering if anyone has seen examples of historic treatments causing similar damage.
The paper is likely to be sourced from Germany due to the printing location. We have located a number of obscure watermarks that have yet to be identified, which we would be happy to make available.
The description of the paper caught my attention. The paper sounded as though it was in some sort of very peculiar unheard of distress. My interest peaked and I contacted Ms. Holland offering my services to analyze the paper in order to help get to the bottom of the strange occurrence. Several samples arrived in the mail. My immediate impression was that the samples were not of 17th century paper (fig. 1).
Fig. 1 The samples are very thin and discolored.
Such paper is usually strong, crisp and of sturdy weight. These samples are wafer thin, fragile and lack any surface definition of a handmade rag paper from the 1600s. The samples appear to be much more like machine-made wove chemical wood pulp from the late 1800s.
Examinations by polarized light microscopy (PLM), x-ray fluorescence (XRF) and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) in the conservation lab would hopefully solve the puzzle. PLM showed that paper fibers are really made of flax (fig. 2). I was stunned.
Fig, 2. Distinctive lumen and nodes are present.
Examining the paper samples in transmitted light revealed laid lines of handmade paper. More stunned. An ATR-FTIR spectrum of the Kepler fiber proved it as a perfect match for a flax fiber reference (fig. 3).
Fig. 3 Kepler paper compared to known flax.
There appears to be no evidence of chemical damage in the Kepler paper’s IR spectrum. Lastly, XRF spectroscopy was applied. A huge amount of chlorine appears in the spectrum (fig. 4).
Fig. 4 A prominent chlorine peak is present.
The presence of chlorine may infer that the Kepler manuscript was bleached at some point during a restoration treatment, no one knows when, with a chlorine-based compound. Racking my brain for clues I remembered something that one of the conservators at the Bibliothèque Nationale (Paris) told me when I worked there many years ago. They have an expression for flattening paper in presses, which translates in English to ‘press it until the ink runs’. It may explain the thinness of the paper. The chlorine treatment may explain the fragility of the paper and its discoloration. The Kepler paper is still a puzzle. The data was sent to Ms. Holland, who was very excited to receive it. She and her student plan on doing more work to solve the mystery of the Kepler paper.
Ted Stanley, Special Collections Paper Conservator