The cataclysmic eruption of Mount Vesuvius in 79 CE, which buried the ancient city of Pompeii under nearly 20 feet (6 meters) of volcanic ash and rubble, left an entire bustling metropole of the Roman Empire preserved in a state of suspended animation. Archaeologists have spent more than a century excavating Pompeii into a diorama of life in antiquity—and they have just confirmed a practice only seen before in ancient Roman texts.
Researchers based in Germany and Switzerland have broken down the structure and chemistry of ash residues obtained from two incense burners unearthed in Pompeii, documenting offerings to the gods that had previously only been described in the work of Roman historians and artists.
“We’ve long known from ancient writers that the Romans burnt frankincense in their sacrifices,” the new study’s lead author, archaeologist Johannes Eber of the University of Zurich, said in a statement. “Preserved ashes and traces of fragrant resins from a domestic shrine near Pompeii provides tangible proof,” Eber added, “and a striking reminder of just how globalised the ancient world truly was.”
A possible funeral, buried in Pompeii
The new study, published Monday in the journal Antiquity, examined the contents of two censers, or incense burners, including one located inside the domestic shrine of a villa rustica at Boscoreale, an agricultural region north of Pompeii at the foot of Mt. Vesuvius. The shrine’s censer, made of fire-resistant terracotta, is rimmed with a sculpted appliqué of a reclining woman, a common memorial addition in Pompeii. “Reclining figures likely depict deceased individuals venerated after their death,” according to the researchers.
The team analyzed the chemistry and microscopic features of organic residues left behind by the burnt offerings, as well as the remaining hard biominerals formed within woody plants and microscopic particles of silica formed inside vegetation, called phytoliths, also present in the ash.
Their analysis yielded the first concrete evidence for the burning of wine and frankincense in domestic Roman rituals, a practice that has been alleged to play a key role in Early Imperial funeral rites and other religious ceremonies. According to Eber, ancient Roman censer resins like these had “only rarely been subjected to detailed analysis” prior to the new study. This ritual practice had never before been verified in the archeological record.
The frankincense itself was unique, too. Eber and his colleagues traced the origins of this particular aromatic tree resin far from its usual sourcing in southern Arabia to the farthest reaches of the Roman Empire’s trade network, somewhere in either India or sub-Saharan Africa.
Eber and his colleagues noted that written sources often emphasize the use of imported frankincense and other incenses for domestic rituals like this. The burning of wine and frankincense together was “among the most commonly enacted preliminary sacrificial acts in Imperial Rome.” It was known as the praefatio—an initial offering designed to invite Roman gods, including Janus, Jupiter, and sometimes others, to bless the rite’s proceedings. In these rituals, “burning wine” meant pouring wine onto an open flame or incense burner, where it would vaporize, mix with smoke, and release a distinct aroma.
In vino veritas (maybe, probably)
The researchers added some caveats to their findings, however, due to the “sparsely documented post-excavation histories” of both artifacts. Although they are confident in their analysis of these ceremonial residues, they note that “some of the identified compounds may be related to natural decay processes.”
In the case of the wine, Eber and his coauthors are mostly going off of fatty and acidic evidence for grapes, including a suggestive combination of succinic, fumaric, malic, and tartaric acids. “A malic-to-tartaric acid ratio of 0.7 could correspond to the chemical signature of a ripe grape product,” as they noted in their study, “such as wine or vinegar.”
But perhaps the most severe reason for caution comes simply from the long and winding chain of custody: One censor was unearthed in 1954 from a buried Pompeii residence that was in the process of being converted into an inn when Mount Vesuvius blew (a lot going on before and after, in other words). And the censor from Boscoreale was discovered in 1986, about 40 years ago now. Crazy things have happened in Pompeii in the 2,000 years since it was buried alive too. (Did you know, for example, that it was partially bombed by the Allies during World War II?) So, it’s worth taking some of these conclusions with a grain of salt, or maybe a few silica phytoliths, for now.
“Post-depositional contamination cannot be excluded,” Eber and his team emphasized, because “no sediment control samples from the context were preserved, preventing the final confirmation that these biomarkers are associated with the original content of the incense burner.”
