Italy’s Mount Vesuvius was so hot when it erupted that it turned one victim’s brain to glass, according to a new analysis of the tragic statues left behind by the volcano’s destruction of Pompeii and Herculaneum.
The cataclysmic blast caught most people by surprise in 79 A.D., when it buried an area of 20 square kilometres under volcanic ash and pumice within just a few hours. The incident encased thousands of victims in ash, preserving their agonized final expressions in moulds that would endure long after their bodies had decayed.
But while most victims’ bodies did decay, researchers say part of one person’s brain survived.
Archeologists say they recovered a piece of brain matter from one victim in Herculaneum, a small city that was closer to Vesuvius than Pompeii when the volcano erupted nearly 2,000 years ago. It’s not the first bit of brain tissue to be found, but where past samples have essentially turned into soap, this new sample was different.
The brain tissue had been turned to glass in a process known as vitrification, according to the study published in the New England Journal of Medicine.
“This is the first ever discovery of ancient human brain remains vitrified by heat,” study co-author Pier Paolo Petrone told BBC News. Petrone led the project in his role as a forensic anthropologist at the University of Naples Federico II.
The victim appears to have been a man in his mid-20s who was working as a caretaker at the Collegium Augustalium, a place of worship in Herculaneum. He was lying on a wooden bed when he died.
Analysis of the charred bed shows the victim was exposed to a maximum temperature of 520 C (968 F). The heat was so intense that it burned the tissue and turned it into glass.
“This suggests that extreme radiant heat was able to ignite body fat and vaporize soft tissue,” the study said. The authors add that a sharp drop in temperature after the blast likely helped in the vitrification process.
Most of the victim’s tissue was transformed into a solid, spongy mass, much like what happened to firebombing victims during the Second World War, the study said.
Petrone says he was analyzing this spongy material when he spotted a few black fragments in the victim’s skull.
“I noticed something shining inside the head,” he told the Guardian newspaper. “This material was preserved exclusively in the victim’s skull, thus it had to be the vitrified remains of the brain.”
Petrone and his team analyzed the glass more closely and found proteins left over from a human brain, as well as fatty acids that would be left behind by human hair.
Petrone says the victim would have died instantly in Vesuvius’ pyroclastic flow — a fancy term for a cloud of hot gas and volcanic matter that swept over Herculaneum and Pompeii following the eruption.
The press office at the Herculaneum historical site hailed the discovery in a statement on Thursday.
“This is the first time ever that vitrified human brain remains have been discovered resulting from heat produced by an eruption,” the office said.
Petrone said the discovery should serve as a sobering reminder for residents of modern-day Naples, who live in the shadow of the same volcano that wiped out Pompeii and Herculaneum in a matter of hours.
Vesuvius has erupted dozens of times since that history-making blast in 79 A.D., and it is still considered to be an active volcano surrounded by a large, vulnerable population.
“Even if sheltered within buildings, people will die due to the high temperatures of the ash surges, as demonstrated by the victims of Herculaneum, Pompeii and even further settlements,” he told the Guardian.
Petrone called the discovery a “silent warning for the three million inhabitants of metropolitan Naples.”