In 1793, people walking around what is now known as Old City in downtown Philadelphia may have been subject to an unpleasant odor permeating the air. A shipment of coffee beans had been dumped on Water Street between Arch and Race streets, along the Delaware River, and left to rot. The stench was apparently so great that Benjamin Rush—a Founding Father, well-known physician, and professor of medicine at Penn at the time—believed it was to blame for a devastating epidemic of yellow fever that struck the city that year.

It wasn’t until a century had passed that mosquitoes were identified as the vector of yellow fever. But historian David Barnes, an associate professor in the Department of History and Sociology of Science, wanted to experience the smell of rotting coffee beans for himself to gain some understanding of how it could have been blamed for an outbreak that claimed the lives of 5,000 people.

“I was always curious about this reference to rotting coffee,” Barnes says. “It’s not something you think of as smelling awful.”

After realizing the difficulty in obtaining a small quantity of green coffee beans, he decided to go big, and share his “sensory experiment” with the public.

Barnes purchased 50 pounds of green coffee beans and left them to rot in a container in his driveway through the summer and early fall. Then, on a Friday evening last month, with assistance from some “co-conspirators,” he dumped the rotting beans out on a tarp, just a stone’s throw from the site where the beans were left out on the docks more than 200 years ago.

Barnes’ friends, colleagues, and students—as well as many unsuspecting passersby—took in the odor.

“It’s pretty awful,” said one.

“I feel like I’m going to get yellow fever from smelling this,” said another.

Barnes is at work on a book about the Lazaretto, a former quarantine station just south of Philadelphia, in which yellow fever plays a starring role. The Lazaretto served as a quarantine station to protect the city against yellow fever and other epidemic diseases throughout the 19th century. Barnes plans to cite the rotten-coffee reactions to shed light on how sensory environments and medical knowledge have influenced one another throughout history.

“I didn’t necessarily have this idea to dump rotten coffee beans on the street because I had some intellectual plan to change the way people think about history,” Barnes says. “But having come up with the idea for fun, I think it’s an interesting provocation to think about history in a different way.”

To view videos of Barnes’ venture, visit his Sensory History website.