French philosopher René Descartes' skull may have been filled with peas, in an old practice known as "skull blasting", according to one group of researchers.
Descartes, of "I think, therefore I am" fame, didn't have the best of times shortly following his death. It's not a great time for anyone, but when Descartes passed away in 1650 his corpse had to deal with rather a lot of thieves. He was first buried in a Catholic cemetery in Stockholm, before being moved to the Sainte-Geneviève in Paris in 1666.
In the 1790s, Descartes' body was dug up again, in an attempt to protect it from the carnage of the French Revolution. When they looked at the remains, however, they found just a tibia, parts of a skull, and a femur. The archaeologist and collector who dug him up – Alexandre Lenoir – reportedly wasted no time in turning the small fragment of skull that remained into rings.
A mystery remained as to what happened to the rest of the philosopher's remains. When he was reburied in 1819, people noticed the missing skull, including chemist Jöns Jakob Berzelius. Berzelius later became aware of a skull that supposedly belonged to Descartes back in Sweden, tracked it down, and bought it from the owner, in order to return it to France.
"Berzelius never doubted its authenticity," a team from Lund University who questions that very authenticity wrote in a book chapter in 2020, "since the names of six individuals, several of whom were eminent Swedish scholars and assumed to be previous owners of the skull, were inscribed on it."
In fact, making it really explicit, the skull had “the skull of Descartes, taken by J. Fr. Planström, the year 1666, at the time when the body was being returned to France" written across the forehead. Planström was one of the people charged with guarding Descartes's corpse, adding to its authenticity. Since then, the skull, believed to be authentic, has resided in Paris's Musée de l'Homme.
But, according to the researchers at Lund University, the skull could be a forgery, while a separate piece of skull thought to be a forgery could in turn be part of Descartes' skull. The piece of skull in question resides at Lund, having been donated in 1780. It had its own inscription, too, with the number six written on it, which the team believes was due to it being part of six fragments created during skull blasting.
"If we are allowed to speculate," the authors wrote, "we know [...] that Planström was plagued by debt collectors."
"Perhaps the fragmenting of the skull and selling of several relics was an attempt to increase the profit."
Skull blasting is an old technique of separating the individual bones of the human skull, either in order to sell it in smaller pieces or for study. Essentially, the method is to take the skull and fill it with an expandable grain, and sometimes dried peas, and then fill it with water to let the expanding grains and pressure do their thing.
For what it's worth, a study in 2014 found that dried chickpeas were the fastest way to blast the skull, beating mung beans by a margin, and easily beating filling a skull with water, sealing the skull, and putting it in a pressure cooker (the method "destroyed the whole skull" if you must know).
The researchers from Lund University believe that the owners listed on the Paris skull are likely inauthentic. For example, one of the owners listed was a bishop named Olof Celsius. According to contemporary inventories, they write, it was not owned by him but by his wife Andreetta Katarina Celsius, and it was a fragment of skull that she owned rather than the whole thing. Andreetta donated a fragment – the piece now in Lund – and ownership never passed to Olof.
The team add that "at least one of the two inscriptions ‘Anders Anton von Stierneman 1751’ and ‘Arckenholtz’ must be false, since the latter specified that he only purchased his piece of skull in 1754, and since it is known that von Stiernman owned his piece until his death in 1765."
"The inscriptions found on the Paris skull clearly contradict the information provided by almost every older historical source," they go on to claim.
The team believe that the Lund fragment is more likely to be authentic, and fits much better with other historical documents and records of fragments of Descartes' skull being sold to private collectors in the 18th Century. The only way to find out, they believe, is to do DNA testing of the competing skull and fragment, comparing it to Descartes' lineage, or better yet by recovering his finger bone for comparison.
The chapter appears in a book titled Collecting curiosities published by Lund University Publications in 2020.