A New York Medical College senior vice president says he found a letter from Charles Darwin in his office closet.

Stephen Piccolo was cleaning out his closet at work when he found the handwritten letter, which dates back to 1879. Darwin, the world famous naturalist who wrote about the theory of evolution, was writing to Ernst Krause, author of a book about his grandfather. 

The Darwin letter wasn't the only artifact hiding in Piccolo's closet. Three years ago, a letter from Albert Einstein was also found there.

New York Medical School says the letters appear to be part of an autograph collection amassed by Dr. Ernst Wynder. The college has slowly recovered the letters over the last decade since buying the building with Wynder's office on Dana Road.

While the letter is just a bit of bland correspondence between Darwin and his grandfather's biographer, the New York Medical College calls it priceless. Some say the letter could fetch up to $4,000 to $5,000 on eBay.

Darwin's letter will go on display along with other letters from scientific greats at New York Medical College's administrative building.