struck by rocks or masonry, crushed inside collapsing buildings, suffocated in a smog of hot ash — most seem to have survived the Plinian phase of the eruption. Nor were their bodies instantly stripped of cloth and flesh like those at Herculaneum; this organic matter decayed slowly inside a casing of volcanic rock. The explanation seems clear: Pompeii is more than twice the distance from Vesuvius, so that Surge 1 was cooler when it reached the town, perhaps only 250°C — sufficient to cause almost instant death, the bodies contracting into the pugilist position as the victims perished, but not sufficient to vaporise cloth and flesh.
‘The apparent defensive position seen in the Pompeii victims,’ Petrone argues, ‘repeatedly cited by various scholars in support of a slow death and terrible suffering, was actually due to the fixed flexion of extremities and limbs induced by heat due to protein coagulation and shortening of the muscles around the time of death …’ Equally misguided, he maintains, are claims that some of the victims seem to be screaming in agony. ‘A radiographic examination carried out by computerised axial tomography (CAT) on a skull belonging to an adult male shows swollen lips protruding (edema), which reflect the high-temperature swelling inside the mouth. Comparison of the face of another Pompeii victim with that of a young soldier who died in the explosion of a tank in Iraq shows as well the common heat-induced features.’ The recent discovery of vitrified brain tissue inside the skull of a Vesuvian victim has confirmed conclusions about the extreme temperature of Surge 1. At lower temperatures, brain tissue can be expected to ‘saponify’ — turn to soap — but some at least of that belonging to the man found on the bed in the College of the Augustales had turned to glass. ‘Features suggesting a maximum temperature of 520°C were detected on charred wood from the Collegium. This suggests that extreme radiant heat was able to ignite body fat and vaporise the soft tissues; a rapid drop in temperature followed. The detection of glassy material from the victim’s head, of proteins expressed in human brain, and of fatty acids found in human hair, indicates the thermally-induced preservation of vitrified human brain-tissue .’ A few minutes more Surge 1 killed everyone at first impact; and then probably dispersed within minutes. But it was followed by the much denser, groundhugging mass of Flow 1. Too heavy to pass over the top of the town, it moved down the valley south of it, then spread out along the beach.
The Past | April/May 2021