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A girl with long dark braids stands at a counter slicing strips of paper.
Tineta Nkoronye cuts strips of paper for testing.

A Blast to the Past: Testing Decades Old Predictions

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The following is a post by Tineta Nkoronye, Intern, Preservation Research and Testing Division. She is a rising Senior at Elizabeth Seton High School and has an interest in the field of biochemistry.

In almost every popular fantasy novel there is a prevalent archetype: the Fortune Teller. Those of us familiar with Harry Potter by J.K. Rowling or, to bring up a personal favorite of mine, The Diviners by Libba Bray have seen how characters like Professor Trelawney and Evie utilize their unique abilities to foresee the future. This concept isn’t confined only to the pages of fiction books as they have deep roots in some traditional cultures and have even seeped into modern pop culture through forms of divination like magic 8 balls and fortune cookies. I mean isn’t it only natural for us to want to mitigate our anxiety about the uncertainties of our futures and find a sense of relief from the fear of the unknown. Even in a field like science that is so based on facts and figures, predictions are fundamental as they play a role in organizing thoughts and research and, even when inaccurate, can help produce new questions. This summer, I had the pleasure of delving into a research project regarding comparing the attributes of historical book paper to predictions made 60 years ago under the guidance of Dr. Andrew Davis through Project SEED – a program designed to provide research experience with high school students. The focus of my research was based on the predictions of the pioneering chemist and paper maker, Willam J. Barrow. His life’s work was dedicated to combating acid deterioration in paper and preserving books, a mission that left an impressionable mark on the world of paper conservation. Barrow and his staff at his research lab, the W. J. Barrow Research Laboratory, carried out extensive physical and chemical tests on 1000 books and made predictions about the future durability of these books based on their properties. Barrow’s research distinguished between paper types—those made from cotton/linen rags, resilient and free from fading due to minimal chemicals, and wood pulp paper, which ages quicker due to its lignin content and shorter fibers. We had the lucky advantage of having direct access to his collection for continued testing, and we set a goal to put his predictions to the test using a range of analytical techniques.

Books encased in grey board boxes with white labels fill a bookshelf.
A sample of Barrow’s extensive collection, Photo credit: Tineta Nkoronye


In order to accurately assess his predictions, our testing methods directly mirrored his original tests using the same equipment and methods. Barrow’s research was built upon a range of chemical and physical tests, with four tests being of specific interest to this project: the folding endurance test, the tear resistance test, the test for acidity/pH tests, and accelerating aging experiments. I focused on two aspects— fold endurance and pH testing. determine the fold endurance of these books I used a strip cutter to cut 15mm wide strips of books from Barrow’s collection. These strips were then put in the clamping devices of the MIT Fold endurance tester to fold these strips of paper under 1/2 kg tension until they snapped. Testing was done individually on strips from each book, and the average was reported for a set of 10 strips. For pH testing, I immersed half-gram samples of 1/8″ square cut paper in 35 c.c. distilled water and analyzed their acidic properties using a pH meter.

Person using an X-ACTO blade to tear out a page from a book.
Me getting ready to cut a page out of one of Barrow’s books, Photo Credit: Tineta Nkoronye
Scientific lab equipment fills a workbench.
The pH measurement system used to conduct pH tests, Photo credit: Tineta Nkoronye


I performed these tests on 49 books and drew comparisons between our findings and Barrow’s predictions. It was interesting to see how the results varied, with some outcomes aligning closely with Barrow’s predictions and others diverging significantly. For example, one of his predictions stated that over an estimated 50-year period, acidic books post 1800 would lose 95% of their fold retention, non-acidic books post 1800 would lose 20% of their fold retention, and books pre-1800 would lose 10% of their fold retention. After performing our tests, I found that 13.3% of acidic post-1800 books, 3.22% of pre-1800 books and NONE of the non-acidic post 1800 books in our sample matched Barrow’s predictions of loss.

Percentage Bar chart
Percentage bar chart of books (based on their paper types) that matched Barrow’s Qualitative Predictions


I also delved into Barrow’s systems classifying paper strength based on fold endurance and tear resistance and the predictions he made based on their production dates. Our findings supported one of his claims which predicted that books produced post-1800 with higher acidity levels could be expected to lose 20-50% of their folding endurance within a 10-year period. I found that books post-1800, regardless of rag content, consistently measured lower fold numbers, indicating a faster rate of deterioration due to increased acidity. This also seemed to support his other claim that 100% rag or part rag content doesn’t assure permanence in books. When comparing newly measured test values to historic values from the same book, I found that fold retention declined and pH became increasingly acidic over time, which was expected. Also expected, books that retained higher fold numbers when previously measured, although they still declined in fold retention over time, managed to maintain a decently high number of folds when remeasured. This especially held true for books produced and published pre-1800, most likely a result of high rag content. The same trend continued with pH as extremely acidic books still presently measured as acidic and books that leaned neutral or even basic didn’t change much, regardless of composition.

A linear graph with a legend
A 1:1 scatter plot depicting the Fold Retention across all Categories


As an avid reader, this project was more than just a pursuit of scientific understanding but also a romantic endeavor to protect the fundamental nature of knowledge that happens to be stored in paper books. Although I’m inclined towards the biomedical aspects of chemistry, this project allowed for a glimpse into the significance of material chemistry and its intersection with seemingly unrelated fields such as history. The transition from a school laboratory setting to an authentic scientific workspace was an amazing experience that only fueled my passion to pursue science as a career. I loved the various opportunities I was presented to discover other facets of preservation. An exciting moment for me was when I was invited to work with other interns on crafting reference cards for pigments. This experience was not only educational but served as an expressive release, as we meticulously layered mixed pigments alongside different binding substances onto paper stocks, allowing them to dry. I was even granted the unique chance to examine maps and paintings that were under study by other scientists, even getting a chance to lay eyes on the very first picture of the capital and listen to professionals articulate its importance and the science required to preserve it.

A black and grey image of the Capitol Building siting on a work mat.
The earliest known photo of the U.S. Capitol. Photo credits: Tineta Nkoronye


A heartfelt appreciation goes out to the committed PRTD team, with special recognition for my mentor, Dr. Andrew Davis, as well as Chief Fenella France, Bobbi Hinton, and Chris Bolser. Their unwavering assistance, support, and guidance have been invaluable during this enriching internship. During my lab experience, I gained a greater understanding of the art of paper preservation, where chemistry, history, and dedication come together in a meaningful way that spans through history.

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