THE poisonous green books they are tomes bound mainly in the nineteenth century and present in various parts of the world, whose cover is dyed with a pigment that contains small quantities of arsenic. During 2024, the National Library of France and the Strasbourg University Library have announced the withdrawal from shelves of some books containing arsenic in the fabric with which the cover is bound. Recently, the National Central Library of Florence has found a volume that could actually contain this poison: it is a copy of The Uncommercial Traveller by Charles Dickens.
In addition to the volumes preserved in libraries, many others may be in private collections and second-hand markets: but how to recognize these volumes?
First, by looking at the color of the cover, which must be a bright green or a pastel green, tending towards turquoise, because it is discolored. At the same time it is certainly not certain that all ancient books with green covers contain arsenic: to dispel any doubt it is obviously necessary to analyze them with careful tests laboratory.
A project promoted by the University of Delaware is examining, collecting and cataloging the poisoned books Poison Book Project: “find out why emerald green is our favorite color”invites the project’s claim “but at a cost”.
What are poisonous green books and why was arsenic used for the covers of the volumes
Copper acetate and arsenic trioxide: this is the combination that creates lCopper arsenite acetate – chemical formula Cu(C2H3OR2)2·3Cu(AsO2)2 – also known as “Schweinfurt green”, “Paris green” or “Vienna green” and it is precisely the pigment with which that beautiful color was given to the covers of some bound books during the nineteenth century.
But how is it possible that, in years when the arsenic toxicitythis harmful pigment has been used for color book covers?
The use of arsenic to create color shades was already known since the end of the Septecnet, but to put it on the market for the first timecopper arsenite acetate was a German company, the Wilhelm Dye and White Lead Company, based in the city of Schweinfurt, in 1814.
That green was not only fascinating, but also buy for a song: within 50 years the “poisonous green” went around the world, and was used not only to color the covers of books with a beautiful emerald green, but also clothes, wallpapers, and other commonly used items.
In those same years, the English publisher William Pickering and the bookbinder Archibald Leighton developed a striking innovation in the world of book trade: the creation of the fabric covermuch cheaper and more resistant than the leather one used up to that point.
And so that the poisonous pigment begins to color the covers of many books in Europe and America. But the fascination for the “green of Schweinfurt” soon gives way to one bad reputation: in fact, we begin to notice that the objects are so colourful they released a powder which caused discomfort, itching and, in some cases, much more serious ailments. This is because the copper arsenite acetate crumbled and, in addition to losing color, was inhaled and ingested.
Thus it was that, in the second half of the century, books colored with arsenic went out of production, but still remained on the shelves of bookstores, libraries and homes all over the world.
How and where to track down books with arsenic: the Poison Book Project
Although the existence of these books has been known for some time, the turning point in the study and consequently in the conservation of “poisonous books” took place in 2019, when the researcher Melissa Tedoneresponsible for the laboratory for the conservation of library material at the Winterthur Museum, Garden & Library in Delaware (USA)is working on a Victorian-era binding.
The volume in question is Rustic Adornments for Homes of Tastedated 1857, and its cover is a beautiful bright green. Tedone notices that the color comes off the surface very easily: perhaps it is a pigment – which therefore does not penetrate inside the fabric – and not of a dyewhich instead has the property of dyeing thoroughly?
The presence of the pigment is thus discovered and confirmedarsenic in book covers, and the research that leads to the foundation of the Poison Book Projectprogram of mapping, cataloging and conservation of books dyed with this poisonous pigment, which then leads the researcher and her team to publish a specific article on the subject.
As of May 4, 2024, the database of Poison Book Projectwhich can be consulted at this link, had 313 books, printed in London, Paris, Berlin, Edinburgh, but also New York, Philadelphia, Boston and many other places.
Green papers containing arsenic: what effects can they have on humans?
The risks of arsenic for humans are neither few nor trivial. In case of inhalation or contact with even small quantities, this substance can cause irritations to the skin or internal tissues, abdominal pain, diarrhea, but also dizziness and lethargy. Only in the case of significant poisoning do we encounter dpermanent years, heart failure, respiratory pathologies and neurological dysfunctions even up to death.
The good news is that, unless the cover of one of these books is swallowed, the danger to humans is minimal given the modest quantities of arsenic present.
But it is one thing to touch a book pigmented with arsenic for a few moments or observe it from afar, but another to spend a long time handling it, perhaps to consult it, study it and restore it.
We therefore understand that librarians, conservators and researchers those who deal with books with poisonous covers must be very careful, and handle them wearing safety devices such as special gloves, as well as carrying out the consultation in a protected place and closing them in sealed envelopes, as highlighted by Melissa Tedone in another dedicated article how to handle poison books.
No, no style intrigues Name of the Rose on the horizon, but in the meantime the research progresses, and the charm of poisoned booksalong with the stories surrounding them, continues to grow.
