U.S. National Institutes of Health

“Arch Street Ferry, Philadelphia,” in The City of Philadelphia, engraving by William Russell Birch, Philadelphia, 1800

Courtesy Library of Congress, Prints and Photographs Division

When yellow fever emerged in Philadelphia in 1793, Dr. Benjamin Rush linked the epidemic to a shipment of coffee beans left to rot on the Arch Street wharf. The “putrid beans had emitted [a] noxious effluvia,” a miasma or bad smell, that seemed to sicken people.