A new study has determined that a rapidly advancing cloud of gas probably overcame a young man who was killed during the volcanic eruption of Mount Vesuvius in 79 CE. Temperatures in the gas cloud likely exceeded 500°C (932°F) and bits of this individual's brain was turned to glass, the work showed. The findings come decades after the remains were recovered - in 1960. This is likely the only case in which vitrified brain matter has been recovered from an archaeological site. The findings have been published in Scientific Reports.
This research has shown how rapid heating and cooling could have occurred during an eruption, and had this impact on organic matter.
The eruption at Mount Vesuvius in 79 CE did not only affect Pompeii; it also destroyed Herculaneum. During this eruption, about 5,000 people probably lived there, in what was likely a typical Roman town.
When Mount Vesuvias erupted and light ash and pumice started to fall on the town, it's thought that most of the town's inhabitants departed. Herculaneum victims were found in boat houses and along the shore, probably waiting to escape by a sea route. One victim that was found around 1960 apparently died after being overtaken by an extremely hot cloud of ash. Scientists observed black stuff within the cranial cavity, which was an unusual finding.
About twelve hours after the eruption started in 79 CE, in the early hours of the day, this hot ash cloud or pyroclastic surge likely overcame the area, and the town of Herculaneum was buried. Ash, rock, and gases swept over the landscape, and anyone who hadn't left perished quickly. In this extreme heat of 400–500°C, flesh was carbonized, and skulls were fractured as the tissue within them began to boil.
This work is a followup of an initial report that identified neuronal material from the brain, in 2020. In this latest study, researchers have outlined the vitrification process. They estimated that this sample of human brain likely transformed into glass as the ash cloud basically overtook the area rapidly, at speeds over 150 kilometers per hour, and temperatures went beyond 510°C. Some parts of the victim's brain likely also broke up into smaller bits. This was followed by a period of rapid cooling to about 510°C, which would be the right temperature for vitrification of the brain.
Sources: Smithsonian Magazine, Scientific Reports
