The advice to never judge a book by its cover may be difficult to apply to Des destinées de l'ame, a 19th century book that scientists have confirmed is bound in human skin.
The book, which is housed at Harvard University's library, is about the human soul.
“The analytical data, taken together with the provenance of Des destinées de l’ame, make it very unlikely that the source could be other than human,” Bill Lane, director of the Harvard Mass Spectrometry and Proteomics Resource Laboratory, told the Houghton Library Blog.
Dr Ludovic Bouland, the man who was given the book in the mid-1880s claimed that it is covered in skin from the "back of a woman."
"I had kept this piece of human skin taken from the back of a woman," he wrote. "A book about the human soul deserved to have a human covering."