Back in 1954, archaeologists uncovered a hidden shrine deep beneath a Greek settlement in Paestum (southern Italy). Inside, they found bronze jars arranged around an iron bed. The jars held a waxy, scented paste that hinted at something ancient and once fluid. Sealed with cork and marked with traces on their surfaces, the vessels held a sticky secret.
Curious minds at London's Bee Research Association asked a German lab to investigate. The residue didn't dissolve in water, but other solvents revealed a fatty, wax-like substance. Bits of plants, insects, and pollen showed up too, though researchers chalked that up to contamination. Some believed the waxy top layer had been added later, masking the original contents within.
By 1970, curiosity still lingered over the strange waxy paste found in these ancient jars from Paestum. Scientists at Rome's Central Restoration Institute ran solubility tests and found no traces of sugars or proteins, just fatty substances like waxes and resins. A sticky puzzle indeed.
Fast forward to 1983, and another lab took up the mystery. This time, analysts from the Rome Chamber of Commerce confirmed that the paste wasn't water-soluble and held no sugary or starchy clues.
What did they find? Remnants of animal or plant fats and phospholipids, ingredients that hinted at something once organic, maybe even ritualistic.
In 2019, the mysterious residue from the Paestum shrine made its way to the Ashmolean Museum for the Last Supper in Pompeii exhibition. This wasn't just a display; it was an opportunity for more scientific investigation. With access to cutting-edge tools and fresh curiosity, researchers seized the chance to reanalyze the substance's biomolecular makeup.
After decades of speculation, Oxford researchers took yet another look at the 2500-year-old waxy residue and struck archaeological gold. Using modern techniques like mass spectrometry and small molecule compositional analysis, they uncovered biomolecular proof that the mysterious substance was once honey, likely in its original honeycomb form.
They also detected sugars, organic acids, and royal jelly proteins in the molecular makeup of the residue. This chemical signature is nearly identical to today's beeswax and eerily similar to modern honey. It's a scientific triumph where ancient ritual meets cutting-edge chemistry.
The team didn't just scrape the surface; they dissected it layer by layer. Using several approaches helped them identify a comprehensive picture of the residue's molecular composition. This enabled them to pinpoint what was ancient, what was contamination, and what had broken down over centuries.
The surface analysis made using X-ray photoelectron spectroscopy revealed traces of copper corrosion tightly bonded with the residue.
The twist? Copper is naturally antimicrobial, and its presence likely kept the sugar molecules safe from decay - as if nature gave the residue a protective armor.
"In preparation for the exhibition 'Last Supper in Pompeii' at the Ashmolean Museum in 2019, our colleagues at the Archaeological Park of Paestum and Veila generously made several important and high-profile loans, including a Greek bronze hydria from the Heroon and its organic contents," explained Kelly Domoney, Heritage Science Manager at the Ashmolean Museum. "We were permitted a unique opportunity to re-analyze those contents using modern instrumentation at the University."
During the exhibition, researchers gave 37 other historical artefacts a modern-science-powered makeover. Using microscopy and X-radiography, they looked beyond the surface, and what they uncovered was a treasure trove of stories hidden in soot and limescale.
They found burn marks on the undersides of some vessels. This hinted at their use over open hearths for cooking. Thick limescale inside others revealed they were likely used to boil water, functioning as ancient kettles.
The team didn't just study artefacts, they also resurrected the rituals and routines of past lives, proving that museum shelves hold more than dusty relics. They're silent storytellers waiting to be decoded.
Researchers believe that this work will inspire further re-analysis of legacy materials, especially those held in museum collections where sampling is limited and earlier tests proved inconclusive.
The study was published in the Journal of the American Chemical Society.
Source: University of Oxford
