THE MUMMY DOCTOR.(Arthur Aufderheide)

At the end of a steep, potholed lane in Duluth, Minnesota, is a three-story brick former elementary school that sits atop a knoll, nearly hidden by a grove of apple and chokecherry trees. A creek flows beneath the building's foundation, through a stone archway. Raspberries and goldenrod edge the windows of the old kindergarten classroom on the ground floor. These days, the building houses an assortment of University of Minnesota science labs. The kindergarten room is the headquarters of Dr. Arthur Aufderheide, one of the world's leading experts on the dissection of mummies, and a founder of modern paleopathology--the study of ancient diseases.

Aufderheide is a tall, straight-backed man of eighty-two who habitually wears a bolo tie and jumps easily from boulder to boulder on a hike. He has the kindness and good humor of a Midwestern country doctor. The day I met Aufderheide in Duluth, he was wearing a brown tweed jacket and a wash-and-wear pullover shirt whose breast pocket bulged with a black leather notebook--his daily uniform. The shirts, he explained, are "designed to be worn without a T-shirt, so you spend less time getting dressed." He led me past a worn marble staircase into his lab, which houses the International Mummy Registry: six thousand withered chunks of liver, lung, brain, and other tissues that he has taken from some six hundred mummies, from the Arctic to the Sahara.

Upon taking over the space, he had blacked out the wall of windows to keep out the summer sun; the room was now illuminated with cool fluorescent light. In one corner, where an old toy chest used to be, sat a rusting, unplugged nineteen-fifties Frigidaire--one of several deceased appliances that provided airtight storage for mummy parts. "I have never cared to possess an entire mummy," Aufderheide said. "It's a formidable challenge to preserve. Even in museums, they often end up getting eaten by insects and mold."

A motley collection of shelves and cabinets contained boxes with labels such as "Cemetery Soil Samples" and "Marc Kelley's Ribs." There were countless books on medicine and on the ancient world, including the works of Diodorus Siculus and Herodotus. "All knowledge is connected to all other knowledge," Aufderheide said. "The fun is in making the connections."

Paleopathologists value the preserved tissues of mummies because they may harbor signs of ailments, or even traces of ancient pathogens. This type of evidence allows scientists to track the historical arc of diseases such as influenza or tuberculosis, and determine the cause of medieval plagues like the Black Death. Aufderheide wonders, for example, why cancer seems rare in mummies, no matter where they come from. Is it because these individuals weren't exposed to industrial chemicals, or is there some other factor at work? "Since this is such a new area, almost anything I do is useful," he said.

Aufderheide has written what is considered the authoritative guide to the field, "The Scientific Study of Mummies," published in 2003 by Cambridge University Press. It includes details such as the nineteen-step recipe used by the Jivaro tribe of Ecuador to shrink the head of a rival killed in war (Step 2: "Transect the neck at the level of the clavicle, pass a band through the mouth and out of the neck, attach a cord and flee the raided village") and illustrations showing how to explore the innards of someone who has been dead for several thousand years.

"Compared to modern bodies, dissecting mummies is salvage pathology," Aufderheide said. "You lose a great deal. DNA falls apart. Often, you're working with an alphabet soup of broken-down proteins where there used to be organs. But we're slowly adapting. The little bit we've done so far shows that we are capable of generating an enormous range of information."