A human brain was vitrified during the eruption of 79 AD

The discovery of cerebral material vitrified in Ercolano requires Therefore very specific conditions that have been revealed by an Italian-German team of researchers led by the volcanologist Guido Giordano of the Department of Sciences of the Roma Tre University and just published on Scientific Reports
entitled “Unique formation of organic glass from a human brain in the Vesuvius eruption of 79 CE”.

AnalisI – who have included the acquisition of electronic microscopy images, the raman spectrometry and warm experiments on the brain fragments – They have shown that brain vitrification took place through a completely unique process of rapid exposure of the organic material first at the highest temperature, at least 510 ° C, and of its next even faster cooling. The glass that was formed as a result of this process allowed an integral preservation of the brain material and its microstructures.

The research group observed that the brain material could not have been glazed if the individual had been heated exclusively by the pyroclastic flows that buried Herculaneum, since the deposits of these flows, whose temperatures did not exceed 465 degrees Celsius, have cooled very slowly and would have totally destroyed the organic material unless it was already transformed into glass.

“Based on our discoveries and analogy with modern observations on volcanic eruptions –
tells prof. Guido Giordano
– Let’s assume that this scenario occurred in 79 AD: after the first hours of eruption that produced the eruptive column observed and described by Pliny the young man, on the night of August 24 (or perhaps 24 October as recent discoveries suggest) the first pyroclastic flows began which gradually destroyed Herculaneum. The first of them reached the city only with its part of clouds of diluted ash but very hot, well over 510 degrees Celsius. He left the ground a few centimeters of very fine ash, but the thermal impact was terrible and deadly, albeit short enough to leave – at least in the only case of the discovery in the collegium Augustalium – remains of brain still intact. The cloud must then be just as quickly dissipated, allowing these remains to cool down so quickly as to trigger the vitrification process. Only later in the night the city was completely buried by the deposits of pyroclastic flows. This scenario is of great importance not only for historical and volcanological reconstruction, but also for civil protection purposes, because it defines a very high danger also for very diluted flows that do not have great impacts on the structures but that can be lethal for their temperatures, whose knowledge can translate into effective prevention and mitigation measures”.

The watchlist’s skeleton in his wooden bed (PPPertron photo)

Dr. Danilo di Genova underlined the importance of experimental analyzes that made it possible to define the thermal history of the material. “To understand the vitrification process, we conducted experimental analyzes by reporting the brain fragments to the temperatures to which they have transformed into glass with heating and cooling cycles at variable speeds with very sophisticated equipment, thanks to a collaboration between CNR-MISMC, the Department of Sciences of Roma Tre and the Technische Universität Claushal.”

View of the archaeological site of Città di Ercolano (photo pp petrone)

Prof. Pier Paolo Petrone He thanks the ten -year collaboration with the Archaeological Park of Ercolano and, in particular, with its director, Dr. Francesco Sirano, who allowed the discovery and study of the brain, and underlines the exceptional nature of the discovery. “A cerebral and spinal material like this, shocking, has not only been found in any other than the hundreds of skeletons of victims of the Vesuvian eruption of 79 AD, but constitutes the only example of the genre known in the world. It is likely that the particular conditions that occurred at the beginning of the eruption in the place of discovery, as well as the protection of the bones of the skull and the spine of the individual have created the conditions for the brain and the bone marrow to survive the thermal impact, then allowing to form this unique organic glass”.