Books are often banned for containing ideas “The Man” considers dangerous, but have you ever come across a book that was literally poisonous? Librarians at a University in Denmark recently did, so now those three books must be handled a bit more carefully.
Sometimes book covers from the Medieval era were made from much older texts, like copies of Roman law. To check, scientists put three 16th and 17th-century books from the Danish library through a X-ray scan. An X-ray was necessary because green paint covered the covers, concealing what texts might be beneath. Under the teeny-tiny beam of light from the X-ray, researchers discovered the green paint contained high levels of arsenic.
During the Victorian era, it was common to use arsenic-based pigment to create a vibrant green color. The paint on these Medieval books is probably “Paris Green,” and it did not get any less poisonous since it was applied. Some well-meaning preservationist most likely painted the old books to protect them against insects and other pests.
Arsenic is one of the most toxic chemicals on earth and can cause cancer and death in addition to the usual poisoning symptoms. It’s most dangerous when it’s ingested, but you can end up poisoned through your skin and breathing in fumes, which Victorians did not know. They believed they were safe as long as they didn’t eat the substance, so it can be found in wallpaper, postage stamps, and even clothing. There’s another book, a copy which can be found at the University of Michigan, that contains arsenic-saturated wallpaper samples collected in 1874. Each page of Shadows From The Walls Of Death is coated in plastic for safety.
Now that the three poisonous books in Denmark have been discovered, the library plans on storing them with precautions similar to Shadows. The tomes will be placed in cardboard boxes clearly marked in a cabinet with good ventilation, so anyone who opens them isn’t met with a gust of arsenic-laced air. Experts also plan on carefully digitising the contents, so the physical copies don’t need to be handled.