Mystery of the 'Swiss cheese' skull solved: Bone powder was harvested from a martyr's skeleton to treat epilepsy in the 18th century

  • Skull belongs to a man who was beheaded by 15th century Ottoman Turks
  • It features 16 circular holes and is on display in Otranto Cathedral, Italy
  • Researchers at the University of Pisa said the marks were created when 'medicinal' bone powder was collected by drilling early in the 18th century
  • Powder was thought to treat strokes, epilepsy and other 'brain illnesses'
  • Skull is the only evidence that small drills were used for this purpose 

Experts have long pondered why the skull of a martyr on display in an Italian cathedral is marked with 16 perfectly round holes.

Now scientists have revealed that the drilling of the skull took place after the man was beheaded by 15th century Ottoman Turk invaders.

It is thought that 'bone powder' was harvested in order to treat paralysis, epilepsy and strokes, believed to be caused by demonic influences in the early 18th century.

A holey skull (shown) displayed in an Italian Cathedral has 16 circular marks from drills because skull powder was collected and used to treat paralysis, epilepsy and stroke in the early 18th century, claims experts

A holey skull (shown) displayed in an Italian Cathedral has 16 circular marks from drills because skull powder was collected and used to treat paralysis, epilepsy and stroke in the early 18th century, claims experts

The skull belongs to one of 800 ‘martyrs of Otranto’ who were executed on August 14, 1480 near the town of Otranto in Apulia, Italy.

They were beheaded when they refused to give up their Christian faith, Discovery reported.

The massacre followed a 15-day siege, where all men over the age of 50 were killed and the women and children either murdered or sold into slavery. 

The skull belongs to one of 800 ‘martyrs of Otranto’ who were executed on August 14, 1480
By studying the cupped shape of the circular marks, experts deduced power was collected with a trepan and rounded drill bit

The skull (left) belongs to one of 800 ‘martyrs of Otranto’ who were executed on 14 August 1480 and has eight holes and eight partial perforations. By studying the cupped shape of the circular marks, experts deduced that powder was collected with a trepan and rounded drill bit (examples shown right)

WHY WAS THE SKULL DRILLED? 

French chemist Nicolas Lémery, who lived at the turn of the 17th century, wrote that added to water, powdered skull can treat paralysis, stroke, epilepsy and ‘other illness of the brain’.

‘The skull of a person who died of violent and sudden death is better than that of a man who died of a long illness or who had been taken from a cemetery: the formers has held almost all of his spirits, which in the latter they have been consumed, either by illness or by the earth,’ he wrote in in his book, Pharmacopée universelle.

The martyrs, whose bones are displayed at the Cathedral of Otranto, were beatified by Pope Francis on 12 May 2013 and are now the patron saints of the city.

But, one of the skulls was set apart from the rest because it featured rounded holes that had been deliberately drilled into it. 

The reason for the drilling had perplexed researchers for years.

Gino Fornaciari, professor of history of medicine and paleopathology at the University of Pisa, Italy, noted the holes are a regular round shape.

Exactly half of them are a conical shape and the rest are partial perforations, according to the Journal of Ethnopharmacology.

Professor Fornaciari said: ‘The perfectly cupped shape of the incomplete perforations leads to hypothesise the use of a particular type of trepan, with semi-lunar shaped blade or rounded bit; a tool of this type could not produce bone discs, but only bone powder.’ 

A trepan or trephine is a surgical instrument used up to drill a burr hole into the skull in order to expose the tissue for medical reasons.

The beheaded martyrs, whose bones are displayed at the Cathedral of Otranto (pictured), were beatified by Pope Francis on 12 May 2013 and are now the patron saints of the town

The beheaded martyrs, whose bones are displayed at the Cathedral of Otranto (pictured), were beatified by Pope Francis on 12 May 2013 and are now the patron saints of the town

Skull powder was used in the 18th century to treat paralysis, stroke, epilepsy and ‘other illness of the brain’. A jar marked 'cranium' is shown

Skull powder was used in the 18th century to treat paralysis, stroke, epilepsy and ‘other illness of the brain’. A jar marked 'cranium' is shown

Bone dust harvested from the skulls of saints or martyrs who died violent deaths was thought to be an effective treatment for a variety of conditions.

Valentina Giuffra, also from the University of Pisa, said that the ingredient was chosen because the head was the most important part of the body and invisible spiritual forces remained active even after death.

French chemist Nicolas Lémery, who lived at the turn of the 17th century, wrote that when added to water, powdered skull can treat paralysis, stroke, epilepsy and ‘other illness of the brain’.

‘The skull of a person who died of violent and sudden death is better than that of a man who died of a long illness or who had been taken from a cemetery: the formers has held almost all of his spirits, which in the latter they have been consumed, either by illness or by the earth,’ according to his book, Pharmacopée universelle.

Drills were likely used to collect the powder before the bones were arranged in the glass cabinet in 1711, although no-one knows why the particular skull was singled out.

The skull is the only evidence to support historical accounts that the macabre ingredient was used in medicine.

The skull belongs to one of 800 ‘martyrs of Otranto’ who were executed on August 14, 1480 near the town of Otranto in Apulia, Italy. The cathedral, where their remains are displayed, is marked on this map

The skull belongs to one of 800 ‘martyrs of Otranto’ who were executed on August 14, 1480 near the town of Otranto in Apulia, Italy. The cathedral, where their remains are displayed, is marked on this map

The martyrs were beatified by Pope Francis on 12 May 2013 and are now the patron saints of the city, whose cathedral is pictured above

The martyrs were beatified by Pope Francis on 12 May 2013 and are now the patron saints of the city, whose cathedral is pictured above

 

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