Books Bound...in Human Skin.

Mental Floss gives a brief history.

From the piece...

The bizarre art of binding books in human skin, or anthropodermic bibliopegy, dates back to at least the 17th century, and involves flaying the body and tanning the skin just like any other type of leather. It has most often been used by doctors as a way to honor a deceased patient or medical colleague, meaning that many surviving examples are anatomical texts such as Leidy’s. Several American universities, including Harvard and the University of Georgia, quietly keep an anthropodermic book or two (Brown supposedly has three), and the University of Pennsylvania library had to put in a distress call to the Admissions office after a tour guide happened to mention their rare skin-bound copy of Biblotheque Nationale and the library was flooded with curious potential students.