Vitrified brain by the eruption of Vesuvius in 79 AD: resolved the “mystery” of Herculaneum

Fragments of glass volcanicoriginating from vitrification of brain fabricswere found in 2020 inside the skull of a young man discovered on the archaeological site of Herculaneumdestroyed together with Pompeii during the historic Eruption of Vesuvius in 79 AD. Now, a team of researchers led by an Italian volcanologist Pierpaolo Petroneidentified one possible explanation For this rare phenomenon: the transformation of the cerebral glass tissues would seem to have been caused by rapid exposure to temperatures equal to or greater than 510 ° Cgenerated by the arrival of a Denies of incandescent volcanic ashwho would have hit the victim and then dissipate themselves just as quicklywith consequent cooling and vitrification.

What does it mean glassing? Volcanic glass and the conservation of brain tissues

The glass volcaniccommonly known as oxidianis a dark color, without one regular crystalline structurewhich is formed following the rapid cooling of a lava Rich in silica. This happens, for example, when lava, with temperatures above 700 ° Ccomes into contact with a liquidlike water. Cooling is so sudden as to prevent the formation of crystals, giving rise to a material amorphous And vitreous. Instead, it is more unique than the case in which the process of formation of volcanic glass “involves” of soft organic fabrics.

In fact, the conservation or vitrification of organic tissues, composed mainly of water, it occurs through rapid cooling at well -lowering temperatures a 0 ° C. In the cryoconvationfor example, the organs, exposed to approx -120 ° C By liquid nitrogen, they acquire the properties of a solid of ice without ice and glass, while maintaining their molecular structure. Other processes are the saponification and the dehydrationbut not the heating.

Nevertheless, in 2020a research team, led by researchers fromFederico II University of Naples, has attributed the origin of fragments glassfound in the fossilized remains of a man who lived a Herculaneum Almost 2000 years ago and the victim of theEruption of Vesuvius of 79 AD – the same that he buried Pompeii -, to a process of vitrification of the soft fabrics of the brain and of the spinal cord, due to the exposure to the high temperatures of a pyroclastic flow. It is a unique case of its kind. Through the analysis under scan electronic microscope and the use advanced images processing tools, scholars would have identified traces of tissue neuronal (axons), as well as proteins (myelin) Municipalities in human brain fabrics and fatty acids typical of the human brain, indicating aorganic origin For those fragments. However, the conditions in which the transformation would take place were not entirely clear.

The cause of the vitrification: an incandescent cloud of ash

A new study, published the February 27, 2025 In the international magazine Nature: Scientific Reportsclarified the process that would have caused the vitrification of brain tissues. Through aCalorimetric analysis with differential scanwhich consists in heating and cooling samples at different temperatures to measure the absorbed or released energy and the speed of thermal transformations, scientists have shown that the transformation of soft glass or enamel fabrics took place at a temperature of about 510 ° C, followed by a quick cooling.

Initially, scientists hypothesized that vitrification had been triggered by pyroclastic flowsa high -speed mixture of volcanic material and gas emitted by Vesuvius, responsible for the burial of Pompeii and Herculaneum below 20 meters Of debris. However, the temperatures of these flows seem to have not exceeded 465 ° C And, moreover, their cooling takes place relatively slowly, a process not favorable to the formation of volcanic glass. On the contrary, the high cooling speed It is in line with the results of the experiments conducted in the laboratory.

Although the brain has not been completely destroyed by heat, it was seriously damaged and fragmented in small sub-decentish fragments-found on the archaeological site-facilitating the thermal exchange during cooling. On the basis of the new evidence and analytical results, scientists speculate now that the transformation of the cerebral glass tissues has been caused by the transitional and short -lived passage of one Denies of incandescent volcanic ash diluted, with temperatures well above 510 ° C. The cloud would have invested the victim at high speed and then disappear quickly, creating the ideal conditions for rapid cooling and vitrification.

Unlike pyroclastic flows, which move along the ground with a dynamic recalls that of an avalanche, a cloud of ash comes transported by the air. This is because it is composed of particles more fine And often it is placed on the edge of the pyroclastic flow itself. Ash clouds can also reach temperatures of 600 ° C. In support of this hypothesis, one would have been found layer ash end At the base of the debris that buried the city of Herculaneum.

The Guardian of the Collegium Augustalium

The skeletal remains of the young man, estimated around twenty years, buried by the pyroclastic materials of the eruption of Vesuvius of 79 AD were originally discovered in the 60s During the archaeological excavations of Collegium Augustaliuma building dedicated to the cult of Emperor Augustus.

The position of the fossil remains suggests that the victim was stretched out on a wooden bed, immersed in the ash. Given the context of the discovery, which took place in a small service room of the building, the experts hypothesize that it was guardian of college.