One hundred years since the discovery of Tutankhamun, a mummy with a lot of chemistry

On October 28, 1925, Egyptologist Howard Carter and his assistants removed the golden nails securing the coffin and lifted the lid. Before them appeared the well-preserved mummy of Pharaoh Tutankhamun. Almost three years—less one week—had passed since the tomb had been discovered. Archaeologists had had to traverse three rooms to reach the one containing the remains. And there they had to open not one coffin, but three. Through a complex game of Russian nesting dolls, they were finally able to access the mummy of the third-to-last pharaoh of the 18th Dynasty, who had ruled for almost 3,350 years.

Tutankhamun's mummy must not only be the most famous mummy of an Egyptian pharaoh, but also the most studied by scientists from various fields. Its excellent preservation has led to extensive analysis, including scans, but the treasures that accompanied it have also allowed for other investigations that shed some light on that period and his reign.

Tutankhamun became pharaoh at the age of nine and died very young—his reign spanned approximately from 1322 to 1314 BC. Therefore, such funeral care and luxury may be surprising. One hypothesis is that the young Tutankhamun, influenced by his advisors, restored the polytheistic religion that his father, Amenhotep IV—who later took the name Akhenaten—had eliminated. And this gave him great importance.

The inner coffin was made of gold and weighed just over 110 kilos. One of the first things to catch the eye was the iconic mask covering its head. It was also made of gold. It weighed about 11 kilos and measured 54 cm high, 39.3 cm wide, and 49 cm thick. X-ray crystallography analysis in 2007 revealed that it had two layers of gold about 0.30 of a millimeter thick. One was 18-karat gold and the other 22.5-karat gold, both in an alloy with silver and copper.

Another notable item was the iron dagger. It had been known since the 1960s to have a high nickel content, suggesting that the material came from a meteorite. Analysis carried out in 2016 confirmed this extraterrestrial origin, which, coincidentally, has a symbolic meaning: the pharaohs were considered deities, and the dagger had been made from a material that had literally fallen from the sky. X-ray fluorescence showed a composition predominantly of iron, with 11% nickel and 0.6% cobalt. This fits with the probable origin of a so-called ferric or siderite meteorite.

Chemistry in Ancient Egypt

Aside from being useful, chemical analysis can be considered a fine homage to the science of Ancient Egypt. Although the word "chemistry" comes from the Arabic al-kimiyaGoing back further, one of the hypotheses is that it comes from Kemet, The ancient name for Egypt, meaning land of the black earth. This would make sense, because this earth was used to make dyes and medicines. That civilization's knowledge of this science allowed them to obtain the first synthetic pigment: Egyptian blue. In its complex preparation, sand, calcium carbonate, malachite—a copper mineral—and sodium salts were mixed and kept for several hours at temperatures between 800 and 1,100 degrees.

To avoid heavy crowns, pharaohs often wore a garment called a nemas. Tutankhamun's mask reproduces a nemas, and metals have been identified that reveal the pigments used. They were Egyptian blue and Amarna blue. The latter is named after the place where Akhenaten built the kingdom's new capital and was only used during that period. The mixture of blues gave the nemas a darker hue.

In 2022, Egyptian researchers published an analysis of small wooden funerary figures found in the tomb. They were ushabtis or shawabtis. The name is believed to mean "those who respond," because they were responsible for the deceased's daily tasks in the afterlife. Using noninvasive techniques such as luminescence and optical microscopy, the pigments were identified: ochre for the red layers, the mineral cuprorivaite mixed with gypsum for the blue layers and with calcite and quartz for the greenish layers, orpiment for the yellow, and gypsum for the white. The black came from animal bones or burned mineral oils.

The level of Egyptian chemistry is also revealed in the mummification techniques, which evolved as embalmers acquired new knowledge. The substances used are found in written sources, such as some papyri, but the identification of the names with the actual compounds is uncertain. Another way to understand them is through chemical analysis of residues. German researchers analyzed the remains contained in 31 ceramic vessels found in a 26th Dynasty embalming workshop in Saqqara. They correspond to techniques used some seven centuries after Tutankhamun's death.

The results, published in 2023 in Nature, lead to conclusions beyond the process practiced by the embalmers. Pistachio resin and castor oil were used for their antibacterial, antifungal, and aromatic properties. Pistachios must have come from other parts of the Mediterranean, but other products, such as dammar gum or eleminoid resin, must have come from tropical areas of Central Africa or even Southeast Asia, where the trees from which they are extracted are found. This shows that, in addition to increasing empirical knowledge about certain substances, mummification also boosted trade with distant regions.

What did the mummies smell like?

Some compounds used in the mummification process can be identified by their aroma. In February of that year, an international team led by Slovenian researchers published in the journal Journal of the American Chemical Society An analysis of nine mummies preserved in the Egyptian Museum in Cairo. Using chromatography, spectrometry, electronic noses, and people trained in odor detection, they identified certain aromas, but attributing them to specific substances is much more complicated. In any case, it could be very useful for conservation.

But this would be the current aroma of mummies. What scents were perceived in funerary monuments in Ancient Egypt? The amphorae found in a 3,400-year-old tomb may provide the answer. They contained food and other items to accompany the deceased to the afterlife. This was the tomb where Kha, an important figure who oversaw the construction of royal funerary monuments during the reign of Pharaohs Amenhotep II, Thutmose IV, and Amenhotep III, and his wife Merit, were buried. The analyses published them in 2022 in the Journal of Archaeological Science An Italian team led by Jacopo La NASA, who, despite his surname, is from the University of Pisa and has nothing to do with the space agency.

The identified molecules are characteristic of dried fish, a staple food in Egypt at the time. Fruity aromas were also present, although the specific product they came from has not been identified. Indicators of the presence of barley flour were found in one of the amphorae—beer was also an important component of the diet in Ancient Egypt—and in others, vegetable fats and beeswax.

From curse to cancer drug

Shortly after the discovery of Tutankhamun's tomb, the coincidence of some deaths—such as that of Lord Carnarvon, who had financed the expedition, and that of his half-brother, Aubrey Herbert—gave rise to the theory of the pharaoh's curse. No evidence supports this, but the legend was revived when, in the 1970s, severe respiratory infections caused the deaths of scientists who had entered the tomb of Casimir IV Jagiello, Grand Duke of Lithuania and King of Poland in the 15th century. Scientific studies have suggested that the deaths may have been caused by Aspergillus flavus, a toxic fungus that can cause these infections with its spores and was also found, in harmless quantities, in the pharaoh's tomb.

In a process completely the reverse of a curse, researchers at the University of Pennsylvania have described this year, in the magazine Nature Chemical Biology, A possible benefit of this mushroom. It contains peptides—short chains of amino acids—called RiPPs. It's an acronym that ties in well with the idea of death, but in this case what they've seen is that some of these substances could have potent anticancer activity. Laboratory tests with human cells pave the way for further research that the authors consider promising. Thus, from the pharaoh's curse, we may have moved on to new drugs, so that good chemistry continues with Pharaoh Tutankhamun.

Tutankhamun's Pea

The pharaoh's name has even become associated with a variety of peas. The Tutankhamun pea, better known as the King Tut purple pea, owes its name to the fact that it was planted in the garden of Highclere Castle, owned by Lord Carnarvorn. It is said, without evidence to support this, that peas were in Tutankhamun's tomb. The fact is that these green peas turn a reddish-brown when heated. And in 2023, Japanese researchers explained their process in the journal Food Chemistry Advances. The culprit has a complicated name, epicatechin, but many of us will have ingested it, because it's found in green tea, among other places. When heated, the substance oxidizes and takes on that brown hue. The discovery, the authors say, will have applications in food coloring processes and in the synthesis of this substance, which has antioxidant power.

The castle is also famous because the interiors and some exteriors of the series were filmed there. Downton AbbeyWith six seasons and three films, it doesn't seem like Tutankhamun's hypothetical curse affected him, but rather the opposite.