(Image Credit: Harvard Law School Library)

A centuries-old book long thought to be bound in human skin actually isn't, researchers at Harvard University said.

Scientist Daniel Kirby determined the book's cover is made from sheepskin, debunking a myth that's piqued students' interest for years.

"I think everyone had their doubts all along," said Kirby, who used a method called mass peptide fingerprinting to reach his conclusion.

He also determined the book's glue is made from cattle and pig collagen. The 17th century book is part of the Harvard Law School's library.

The legend's origin can be blamed on an inscription on the last page of the book, written

"The bynding of this booke is all that remains of my dear friende Jonas Wright, who was flayed alive by the Wavuma on the Fourth Day of August, 1632," it reads, according to a blog post on Harvard's website. "King Mbesa did give me the book, it being one of poore Jonas chiefe possessions, together with ample of his skin to bynd it. Requiescat in pace."

But Kirby's results don't mean the book was never bound in human skin.

"It's a possibility that it had been recovered before it came into the collection," he said.