George Preti, an organic chemist who devoted his career to studying bodily odors and how they can be weaponized in detecting disease, died on March 3 in Hatboro, Pa. He was 75.

The cause was bladder cancer, according to the Monell Chemical Senses Center, a Philadelphia-based research institution funded by philanthropy, government grants and corporate sponsorships.

Ever since he was a regular passenger on the New York City subways, Dr. Preti (pronounced PRET-ee) had thrived on pungency, discovering how individual smells can distinguish human beings like fingerprints.

“We’re all little chemistry factories,” he told The New York Times in 1995. “We have bacteria mingling with excretions from the body that form a variety of odors depending on what part of the body we’re talking about.”