Wednesday, September 7, 2011

Youth in the Service of Age

From the desk 
Conservator at the 
Royal BC Museum

David Douglas was a hard-working Scottish botanist.   When he died, aged 35, he had introduced about 250 North American plants to British gardeners.   In addition to the Douglas Fir, he described 7,000 of the 92,000 plants known to botanists in the early 19th century.  Over eighty plant and animals have douglasii in their scientific names.

Douglas' often requested book of sketches alongside a Pseudotsuga menziesii cone 

He travelled to the Pacific Northwest in 1824 and 1830.  His Book of Sketch maps of a Journey from the Junction of the Columbia and Okanogan Rivers to Quesnel and North, April to May 1833 is in the BC Archives and frequent requests are made by researchers who wish to view or photograph the manuscript maps.  Unfortunately the book is in very poor condition; it is too delicate to travel and photography is difficult because of the damaged binding.  The 25 single-sided pages containing the maps sketched in iron gall ink are relatively stable at the moment, but iron gall ink is notoriously destructive to paper.
We are very fortunate this summer to have Emilie van der Hoorn, an intern from the University of Northumbria (UK) working with paper conservator Betty Walsh.   Emilie has a particular interest in iron gall inks and she tested the pages with Iron Indicator Paper developed by the Netherlands Institute for Cultural Heritage.  These revealed that there are loose Fe2+ ions present which will catalyze the degradation of the cellulose; in time the ink will eat through the paper. 
She has proposed that the iron gall ink be treated soon to preserve the relatively good condition of the sketches, and that the remaining pages of the book be washed and de-acidified.  There are two options for treatment.  The least invasive would be to interleave sheets of gelatin impregnated alkaline paper between the inked pages.  These would neutralize acids to a pH at which the gelatin could complex the Fe2+ ions preventing migration of the corroding ink to facing pages, but not preventing acids and ions embedded in the paper from degrading further.  Alternately the pages could be treated with a calcium-phytate method.  Developed by the Rijksdienst voor het Cultureel Erfgoed in the Netherlands, this would leave the paper cleaner, probably more supple, deacidified, and with an alkali reserve to counter future acid buildup; ink corrosion would not continue.  The book would have to be taken apart, and rebound after the treatment was complete, however the binding is fairly ordinary and, once apart, the manuscript maps could be better photographed for use by researchers. 

It is always a difficult decision to disassemble an artifact.  Although conservators aim for reversibility in their treatments, in many cases this is impractical.  Conservators also tend to be … conservative, unwilling to experiment with treatments that have not stood the test of time; there are many cases where doing nothing has caused less damage than elaborate “improvements”.  However, the problems with untreated iron gall ink are well known.  

Interns challenge us with their questions, inspire us with fresh ideas from their recent studies, and galvanize us with their youthful energy.  Because of the crush of other projects, treatment of the Douglas Sketchbook will happen after Emilie has returned to her studies, but in the meantime we have all benefitted.  Emilie examined, analyzed and articulated the treatment of a valuable artifact, the Archives received the perspective of two of the leading schools of paper conservation, and the manuscript maps of David Douglas are poised to illuminate future research.

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The Royal BC Museum is located in Victoria, British Columbia on Canada's west coast. We preserve BC's human and natural history and share it with the world. How do we do that? That's what this blog is about.

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