The stone stairway that leads down into the Capuchin Catacombs in Palermo, Sicily, might at first offer relief from the Mediterranean heat—until you see the corpses, all 1800 of them, lining the rock-cut walls.

The mummies’ clothes chronicle a few centuries of fashion choices. You can see virgins wearing flower crowns and slain soldiers in uniform. Some of the bodies still have desiccated skin over their hands and faces. Some lie on shelves, while others are propped up vertically, their mouths contorted in what looks like a scream. Biological anthropologist Dario Piombino-Mascali assures me these tortured expressions had nothing to do with the emotional state of the deceased; it’s just a natural effect of decay.

The Catholic crypt, which dates back to the end of the 16th century, was built in southern Italy at a time when many friars, church-going elites, and later middle-class people were turned into relics after death, not buried underground. The crypt has long been a religious site and morbid tourist attraction. But only recently has it also become a place for serious science, thanks to Sicily native Piombino-Mascali, who convinced the friars who live next door to let him study the collection. “I wanted to do something for the place where I was born, and also because we have so many,” Piombino-Mascali tells mental_floss. “I thought it was about time to study them properly and to obtain firsthand information on them.”

As part of his Sicily Mummy Project, which started in 2007, Piombino-Mascali and his colleagues have examined hundreds of mummies scattered across the island. By looking for subtle traces of life, from the pollen in mummified feces to the gunk on mummies’ teeth, they’ve reconstructed the health, diet, and even social status of long-dead individuals—all while managing to preserve the corpses.

Piombino-Mascali is, of course, not the first scientist to be interested in mummies: In the 19th century, European scholars caught up in “Egyptomania” commonly examined mummies via dissection, much like they might have conducted autopsies on the newly deceased. The practice was so fascinating to the public that “mummy unwrapping parties” became popular in Victorian England. Today, scientists are considerably more careful with their specimens. Less destructive investigation techniques, such as advanced imaging technologies, preserve the specimens being studied. Piombino-Mascali says he even saves the dust that’s cleaned off his mummies to learn more about the creatures like mites that might live in Sicilian crypts.

To see inside corpses without using a scalpel, archaeologists have used X-rays since 1896, when, only a few months after X-rays were discovered, a German physicist X-rayed Egyptian mummies at the Physical Society of Frankfurt. But with the advent of DNA testing, what researchers can learn from mummies—and the cultures they came from—has ballooned. Researchers, for example, have found stomach parasites and even a predisposition for heart disease in Ötzi the Iceman, a frozen mummy found in the Alps. And analyzing the hair of Chilean mummies recently proved that people were consuming nicotine in the Andes at least 2000 years ago.

The Sicily Mummy Project takes advantage of this newly expanded tool kit to study what may be the largest collection of mummies in the world, yielding new insights about life for a historical cross-section of the upper and middle class in Italy. Overall, most of the mummies showed signs of a good diet, high in animal products like meat, dairy, and seafood. In hair samples from the Capuchin Catacombs, the researchers found traces of ethyl glucuronide, a byproduct of alcohol consumption. The results of these mummy drug tests suggest that, yes, wine—one of Sicily’s most important agricultural products today—was indeed an important part of the local diet. (But not for kids. None of the hair samples from six child mummies bore evidence of underage drinking.)

The good life had some downsides; among the mummies examined from the town of Savoca, for example, the researchers found cases of a skeletal disease called DISH and gout, conditions that could be linked to a protein-rich diet. In another recently published study, the Sicily Mummy team focused on the corpse of an unidentified adult male who died in his 40s and was interred at the “Sepulcher of the Priests" at a church in Piraino sometime between the late 18th and mid 19th century.

This priest had a severe whipworm infection at the time of his death and was likely suffering from myeloma (a type of cancer), as well as residual symptoms from a lung infection. His body wasn’t entirely intact, which allowed the team to pry a sample of fossilized poop—technically known as a coprolite—from an opening in the mummy’s abdomen. In the feces, they found wheat pollen and chaff, suggesting he ate bread and pasta before he died. He had also ingested pollen from Polygala vulgaris, or common milkwort. This plant has been consumed as a tea for medicinal purposes in other parts of the world, and its active compounds include anti-tumor agents; the researchers speculate perhaps milkwort may have been part of this man’s cancer treatment.

In addition to insights on historical medicinal treatments, the Sicily Mummy Project has also helped reveal what happened after cures failed. Mummification was common in southern Italy up until the 19th century, when it was largely outlawed for hygienic reasons. The team’s survey of corpses confirmed that most of Sicily’s mummies were created by “spontaneous desiccation.” There’s a conspicuously empty—and repulsively named—chamber at the Capuchin Catacombs called the “draining room,” where dead bodies were once laid out over terracotta pipes or basins to dry out over the course of a year. After bodily fluids had naturally drained from the corpses, they would be washed with vinegar and dressed for display. For Italian Catholics, the passage to the afterlife could be a long, gradual process, mirrored by the material transformation of the corpse.

“This practice of draining the bodies seems to be like a physical representation of purgatory, which was a very popular concept in Catholic Italy,” Piombino-Mascali says.

However, other corpses in Sicily were artificially mummified after death. The Capuchin Catacombs’ most famous resident, Rosalia Lombardo, a 2-year-old girl who died of pneumonia in 1920, has earned the nickname “Sleeping Beauty” because of her pristine mummification; in 2009, Piombino-Mascali discovered a handwritten record of the chemical mix her embalmer used.

His team also found some less conspicuous cases of intentional mummification in the crypt. For example, they used a digital X-ray to scan the whole body of a man who, based on his clothing, looked like he died in the mid to late 19th century. They found that his arteries were full of a metallic substance, suggesting that he had been injected with an embalming fluid like arsenic and mercury. “The perfect distribution of the embalming fluid, especially into the peripheral parts of the body, demonstrates the high quality of the embalmer’s workmanship at the time,” the researchers wrote.

But having a scientist’s perspective on the mummies doesn’t mean Piombino-Mascali has a cold view of his specimens. The opposite might be true. Several times he scolded tourists for taking pictures in defiance of the “No Photos” signs tacked to walls. Because the crypt is a religious site, the friars who maintain it are extremely strict about prohibiting photos and video.

In the crypts, it can be easy to forget that you’re standing in the final resting place of real people, some of whom died not so long ago. Piombino-Mascali is careful in his treatment of the mummies because he knows they’re at risk—humidity and salt deposits introduce microbes that can colonize the corpses. In Palermo, the team has taken tiny samples of the mummies’ skin, muscle, hair, bones, and even clothes to identify the bacteria and fungi that are speeding up the corpses’ degradation. They hope that they’ll be able to recommend research-informed conservation methods so that the mummies remain in their remarkable state for many more years—and so scientists of the future, using even more sophisticated tools, can study them.

All images courtesy of the Sicily Mummy Project