Informal Research on Washing and Deacidification

Since last August, I have been pursuing an informal treatment study on batches of Civil War-era documents undergoing washing and deacidification.  Today, I’d like to share some informal, preliminary results.  First, a very cursory overview of some relevant conservation chemistry.

Paper inscribed with iron gall ink, like these Civil War documents, frequently undergoes two types of degradation.  One type is caused by the presence of acid in the paper.  The second type is caused by the presence of iron ions in the ink.  Both types of degradation weaken paper, causing it to discolor, become brittle, and break.

Washing and deacidification treatments address the first problem by neutralizing pH and adding alkaline buffer.  In recent years, chelation treatments have been developed to address the second problem.  These treatments lock up iron ions and make them unable to continue damaging paper. 

I frequently pursue washing and deacidification in the TSLAC lab, and I have been considering introducing a chelation workflow, as well.  To help make that decision, I decided to evaluate the effectiveness of my current treatment by measuring acidity and iron ion presence in the Civil War documents before and after treatment.  Surface pH is measured with an Extech handheld pH meter, and iron ion presence is evaluated with iron gall test papers developed by the ICN conservation program in the Netherlands.  I classify the test paper results from 0 (no iron ions indicated) to 4 (iron ions strongly indicated.)

Given published research, I expected that washing and deacidification would affect paper pH strongly, but would have a negligible impact on iron ion levels.  My preliminary results are surprising.  Average pH increase was more modest than expected: it changed from 4.40 before treatment to 5.56 after, for an average change of 1.16.  Average reduction in iron ion presence was more pronounced than expected:  rankings changed from 1.7 before treatment to 0.4 after, for an average change of -1.3.  Not only does the after-treatment paper remain surprisingly acidic, but it also shows a surprisingly marked reduction in iron ions given that chelation was not pursued. 

These results are very informal, and testing continues monthly.  Myriad explanations can be imagined, not least including inaccuracies inherent in surface pH measurements.  (The unsuitability of destructive sampling is a frequent challenge in conservation research.)  Perhaps additional baths are needed to improve pH.  Perhaps without chelation, the iron ions become more diffuse during washing, creating risks less localized but more pervasive.  I’d be very curious to hear other conservators’ thoughts and interpretations as I consider future washing, deacidification, and chelation treatments.

Archival Serendipity

As I gradually de-silk, deacidify, mend, and sleeve our collection of Confederate muster rolls, I receive periodic inquiries from the reading room staff as to whether work on a particular requested document is completed.  Untreated muster rolls are not available to researchers due to their extremely fragile condition.

This week, I was surprised to receive an inquiry about a muster roll whose treatment I had just completed three days earlier.  I recognized this particular muster roll by number right away for several reasons.  First, it had arrived in the lab in nine separate pieces and had been reassembled into four complete sheets, one a giant 32.5” x 42.5”!  Beyond the physical condition, I also immediately noticed that this muster roll was filled with Hispanic surnames, something I’d never observed in other similar documents.  Not only was I excited that such recently completed work should be requested by a researcher, but I also hoped to potentially learn a little more about this unusual document. 

The researcher told us that this muster roll represented a unique intersection of Civil War and Tejano history.  When the Civil War broke out, many Tejanos did not support the Confederacy, and they lost land and status.  By contrast, the prominent family of Santos Benavides in Laredo allied themselves with the Confederacy.  Benavides took his staff and servants into battle, and their names are listed on the muster roll.  Benavides eventually became a colonel, the highest ranking Tejano in the Confederate Army, and participated in several significant battles.  Far from encountering ill fortune during the war, Benavides, the son of Laredo’s founder, remained a major landowner and political figure in Laredo until his death in 1891. 

How fortunate to learn more about this unusual document, and how fortunate the timing of the research and conservation work!  Many thanks to our researcher for taking the time to talk about Benavides’ story.  I look forward a forthcoming journal article on the topic.

Audio Preservation Conference in Berlin

I was most fortunate to be an invited speaker at the International Seminar on Preserving Endangered Audio Media in Berlin last week.  The conference’s unique focus was captured in its subtitle: “Rethinking Archival Strategies for Conservation of Analogue Audio Carriers.” Oftentimes, due to the rapid degradation of modern media and the obsolescence of playback technology, “audio preservation” is simply taken to mean “digitization.”  But as Paul Banks observed in his Ten Rules of Conservation, “The physical medium of a document contains information” and “No reproduction can contain all of the information contained in the original.” These concepts are true in audio media as well as in books and paper.  This conference addressed the conservation of audio carriers in addition to their content, and in so doing offered a refreshing perspective on difficult issues in new media preservation. 

Why should we care about tapes, records, or cylinders as physical artifacts instead of just source recordings for mp3s?  Several presenters offered perspectives.  Susanna Belchior of the Universidade Nova de Lisboa (Portugal) discussed how original discs, with their labels and packaging, are helping researchers construct a history of the Portuguese recording industry.  The discs offer invaluable information about when and where the recordings were made.  By pairing these primary recorded resources with available ledgers and account books, researchers can begin to understand how the practice and economics of recording evolved in Portugal.  Belchior also suggested that chemical analysis of the physical discs might yield information about specific shellac or vinyl formulations used by particular institutions or in particular regions.  This talk reminded me a lot of a National Archives talk given at the American Institute for Conservation 2011 meeting in which artifactual evidence in book bindings enhanced existing understandings of book binders and their work in revolutionary America.

Silke Berdux and Nadia Wallaszkovits, respectively of the Deutsches Museum and the Austrian Academy of Sciences, discussed a fascinating preservation project focused on the open-reel tape recordings of electronic music innovator Oskar Sala (here is some basic info in English.)  As an experimenter in the recording studio, Sala used many unconventional techniques, such as switching among tape speeds, changing the number of recorded tracks, and splicing many different tape types together.  Sala’s work reminds me a great deal of fellow electronic music inventor Raymond Scott, on whose materials I was fortunate enough to work at the Marr Sound Archives.  I imagine Sala’s tapes would also share commonalities with those produced by the musique concrete innovators, as well; all of these individuals worked in audio tape as a primary medium.  As a result, the physical tape shows as much about the experimentation process as does the recorded content.  In order to better preserve both the visual and sound information in the Sala archive, high-definition video of the tape was taken during playback and paired with the tape’s digitized audio.  The resulting audio / video file is an elegant preservation solution that captures far more information than would the audio or video alone.  

At the conference’s conclusion, George Brock-Nannestad raised the following (paraphrased) question: How can we argue for the preservation of physical recordings when interest in them as artifacts seems like a fairly niche, academic pursuit?  This is a great question, and one that often bothers me at conferences.  More broadly, how can we argue for the importance of physical things in a world that is increasingly digital and intangible?  I think one answer is this: heritage caretakers, historians, and other allied professionals can conduct research that contextualizes material studies within broader trends in history, art, and the humanities.  For example, what can types of paper fibers tell us about trade routes?  What can binding styles tell us about the economics of a region?  What do tape splices say about the creative process? 

As a final note, I recently purchased a copy of Trade in Artists’ Materials: Markets and Commerce in Europe to 1700, edited by Jo Kirby, Susie Nash, and Joanna Cannon and published by Archetype Publications.  Most of the materials discussed in this volume are much older than anything I encounter at the Texas State Archives.  However, I hope the book will offer a model for the type of conservation research described above: a blend of material evidence with history, trade patterns, economics, and the arts.  So here’s to future research rooted in physical heritage, research that makes the argument for preservation implicitly.