From brain tissue to gallstones, doctors have long preserved specimens from their patients  sometimes as trophies, sometimes as teaching tools, sometimes as curiosities or even art. But Dr. Chevalier Jackson went much further than most.

A laryngologist who worked in the late 19th and early 20th centuries, he preserved more than 2,000 objects that people had swallowed or inhaled: nails and bolts, miniature binoculars, a radiator key, a child’s perfect-attendance pin, a medallion that says “Carry me for good luck.”

Jackson retrieved these objects from people’s upper torsos, generally with little or no anesthesia. He was so intent on assembling his collection that he once refused to return a swallowed quarter, even when its owner threatened his life.

“He was a fetishist, no question,” said Mary Cappello, the author of “Swallow” (New Press), a new book about Jackson and his bizarre collection. “But his obsession had the effect of saving lives. That’s kind of amazing, and lucky for us that his madness made possible forms of rescue.”