The surprising chemicals used to embalm Egyptian mummies
Labelled pots found in a 2,500-year-old embalming workshop have revealed the plant and animal extracts used to prepare ancient Egyptian mummies — including ingredients originating hundreds and even thousands of kilometres away.
Chemical analysis of the pots’ contents has identified complex mixtures of botanical resins and other substances, some of them from plants that grow as far away as Southeast Asia. The discovery was reported in a 1 February paper in Nature.
Previously, insights into the embalming process have come from two main sources: historical texts and chemical analyses of the mummies themselves. But linking these strands of information has proved difficult, says Salima Ikram, an archaeologist and mummy specialist at the American University in Cairo. “You might have the name of something, but you don’t know what the hell it is, except the hieroglyphics suggesting it’s an oil or a resin.”
That has now changed thanks to an underground embalming workshop discovered in 2016 at Saqqara, an ancient Egyptian burial ground in use from 2900 BC or earlier. The site also includes burial chambers, and it is likely that elite members of society were interred there, the authors say. Inside the Saqqara workshop, which dates to 664–525 BC, archaeologists discovered dozens of ceramic vessels used in the embalming process, many labelled with the ingredients they contain and their use. “This is the first time you’ve got jars with labels of the contents,” says Ikram.
To identify the specific contents of the vessels, an Egyptian–German team analysed the mixtures using a technique called gas chromatography–mass spectrometry, at a National Research Centre laboratory in Giza, Egypt. This showed that the pots contained substances previously linked to mummification, including extracts from juniper bushes, cypress trees and cedar trees, which grow in the eastern Mediterranean region. The team also found bitumen from the Dead Sea, along with animal fats and beeswax, probably of local origin
But the researchers also identified two surprising ingredients: one resin called elemi, which comes from Canarium trees that grow in rainforests in Asia and Africa; and another called dammar that comes from Shorea trees found in tropical forests in southern India, Sri Lanka and southeast Asia.
“Egypt was resource poor in terms of many resinous substances, so many were procured or traded from distant lands,” says Carl Heron, an archaeological scientist at the British Museum in London.
Ancient trade networks connected India and southeast Asia with the Mediterranean region. But it’s not clear whether Egyptian embalmers sought out these specific ingredients or came across them through trial and error, says Ikram. “Absolutely amazing”, she says. “Who would have thought that they were getting stuff that might be coming from India?”
Ancient Egyptian embalmers had a sophisticated understanding of the raw materials’ properties, the authors say. Pots contained complex mixtures of ingredients that, in some cases, had been carefully heated or distilled. Many of the resins had antimicrobial properties — one bowl containing elemi and animal fat was inscribed “to make his odour pleasant” — or characteristics that promoted preservation.
“Their knowledge of these substances was incredible,” says study co-author Maxime Rageot, a biomolecular archaeologist at the University of Tübingen in Germany.
Chemical studies of mummies suggest that embalming recipes became more complex over time, notes Rageot. But one open question is how ancient Egyptians developed specific embalming procedures and recipes — and why they selected certain ingredients over others, said study co-author Mahmoud Bahgat, a biochemist at Egypt’s National Research Centre in Cairo, at a press briefing. “We need to be as clever as them to discover the intentions.”
Nature, 1 February 2023