They say not to judge a book by a cover, but what if the cover is made of human skin?

When a doctor received a book as a present in the 1800s, he wrote in a note left with the book that he had covered it with "this piece of human skin taken from the back of a woman." Now, Harvard conservators and scientists say they are 99 percent sure that Dr. Ludovic Bouland was telling the quite literal truth. An analysis of microscopic samples from the binding through peptide mass fingerprinting revealed the substance to be human or a related primate.

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Further testing determined the order of amino acids, often unique to species, and also pointed to human skin as the source.

Although this particular book is the only book at the university known to be covered in human skin, it wasn't that unusual in the 1800s. Skins of executed criminals were sometimes donated to tanners and bookbinders, according to the Harvard library's blog. In this case, the bookbinder used skin from the "unclaimed body of a female mental patient who had died of a stroke."

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Before you judge, consider the bookbinder's words: “This book is bound in human skin parchment on which no ornament has been stamped to preserve its elegance. By looking carefully you easily distinguish the pores of the skin. A book about the human soul deserved to have a human covering."

Photo: Harvard University/Houghton Library