Imagine being a bookbinder in the 16th and 17th centuries when you would recycle earlier materials into your current book. People have discovered remnants of medieval manuscripts, Roman law, and canonical law made into the cover of a newer book.
Once the covers were made, someone then painted it over obscuring the original material. At least three books in the University of Denmark library meet this description.
Scientists took these books to be checked by x-ray technology to learn more. They were hoping to read the remnants in the cover but during the micro-XRF, it was revealed the green paint was arsenic, a poison often used in murder mysteries. Arsenic is considered one of the most deadly poisons out there. Exposure to this substance can lead to cancer or death.
Arsenic is one of the ingredients of Paris Green, or Emerald Green because it is a green similar to the gemstone. The size of the grain determines the shade of the paint. The smaller grains produce a lighter green while the larger ones produce a darker green. In addition, this color does not easily fade and has an intense color.
By the 19th century, Paris Green was commercially produced and used in a variety of ways from book covers to clothing. It was used to dye stamps designed to be licked or in dresses worn to balls, etc. Both exposed people directly to the poison. The problem with arsenic paint is that particles can end up in a person's lungs and in certain circumstances, the paint produces a poisonous gas.
In the case of books, it is thought they were covered with Paris Green
to protect them from bugs and other insects. Although they only found
three books at the University of Denmark other universities could have
deadly books on their shelves. The University carefully placed the
three books in special containers so no one is accidentally poisoned.
By the second half of the 19th century, Paris Green was known to be poisonous but that did not mean it immediately ceased being used. At one point, an American doctor created books filled with samples of wall paper containing arsenic which he sent out to libraries around the country. The book was supposed to warm people but it also poisoned a few. Today only four copies are still in existence but they are carefully handled.
Unfortunately, even after the dangers were known, people didn't immediately throw things out. Many items remained in family homes until they were donated to museums and libraries where they reside today. Museums and libraries need to check their inventory for arsenic so people stay safe.
Let me know what you think. I'd love to hear. Have a great day.