Parasite Eggs Help Archaeologists Identify Ancient Roman Chamber Pot

The ceramic vessel contained whipworm eggs found in human feces, debunking the theory that it simply served as a storage jar

Chamber Pot
The chamber pot stands about 12.5 inches tall and measures 13.5 inches wide at the rim. R.J.A. Wilson

It may look like an ordinary storage jar, but some 1,500 years ago, a ceramic orange vessel unearthed at a site in Sicily served a rather different purpose: Ancient Romans used it as a chamber pot, reports Nicholas Bakalar for the New York Times.

The key to this identification was a calcified crust scraped off the bottom and sides of the pot. Upon analysis, researchers realized that the substance contained parasitic whipworm eggs commonly found in feces. Though the findings, published in the Journal of Archaeological Science: Reports, focus on just one specimen, they could influence how experts interpret similar ceramics found at other dig sites.

“Conical pots of this type have been recognized quite widely in the Roman Empire, and in the absence of other evidence, they have often been called storage jars,” says study co-author Roger Wilson, an archaeologist at the University of British Columbia, in a statement. “The discovery of many in or near public latrines had led to a suggestion that they might have been used as chamber pots, but until now proof has been lacking.”

Pieces
Archaeologists reassembled the clay commode, which was found broken into pieces. R.J.A. Wilson

Researchers uncovered the clay vessel in 2019 at a fifth-century C.E. Roman villa near the town of Gerace. Found in fragments, the reassembled pot stands about 12.5 inches tall and measures 13.5 inches wide at the rim, according to Brandon Specktor of Live Science.

Early Sicilians may have used the ancient porta-potty simply by sitting on it. But the study suggests that they probably placed the vessel under a wicker or wooden chair with a hole in it. Roman records mention chamber pots made out of gold or onyx, but only terracotta and bronze vessels have been found to date, reports the Times. Beyond the Roman world, archaeologists have unearthed ancient chamber pots in Jerusalem, Egypt and Greece.

The section of the villa where the pot was found—outside of a tepidarium, or warm room, in a bathhouse—offered a clue to its purpose.

Whipworm
Scientists found whipworm eggs in concretions scraped from the inside of the clay vessel. Sophie Rabinow

“It seems likely that those visiting the baths would have used this chamber pot when they wanted to go to the toilet, as the baths lacked a built latrine of its own,” says co-author Piers D. Mitchell, a biological anthropologist at the University of Cambridge in England, in the statement. “Clearly, convenience was important to them.”

Built around 380 C.E., the estate’s baths were damaged by an earthquake in the second half of the fifth century. Though the villa’s owners attempted to repair the baths, they eventually abandoned these plans in favor of stripping most useful materials and filling in the area. The chamber pot was likely buried during this “stripping and filling-in period,” writes Jennifer Ouellette for Ars Technica.

According to the statement, the paper marks the first time that researchers have identified parasite eggs in concretions found in a Roman ceramic vessel.

“We found that the parasite eggs became entrapped within the layers of minerals that formed on the pot surface, ... preserving them for centuries,” says study co-author Sophie Rabinow, a biological anthropologist at Cambridge, in the statement.

Residue
Minerals from urine and feces accumulated in the pot, trapping parasite eggs on its surface. R.J.A. Wilson

To separate organic material from the concretions, researchers at Cambridge’s Ancient Parasites Laboratory placed the sample in an acid bath. They then used microscopy analysis to identify the whipworm eggs. (Per the Centers for Disease Control, whipworms live in the lining of the intestine and are most often found in warm or humid climates.)

Ceramics are among the most common archaeological artifacts recovered from ancient Roman sites. To identify parasites preserved in these vessels, scientists can use DNA or protein analysis. But the acid bath technique pioneered by Rabinow and her colleagues is quicker, cheaper and (if performed properly) more reliable, the Times reports.

“The thing that stood out in the paper is their method could be developed so that we could have a general method for everyone,” Karl J. Reinhard, an environmental archaeologist at the University of Nebraska who was not involved in the study, tells the Times. “It’s simple and something anyone can do anywhere. It could be applied to museum specimens as well.”

Rabinow, for her part, says in the statement that “parasite analysis provides important clues for ceramic research.”

Speaking with the Times, she adds, “It’s a good addition to the ceramist’s tool kit.”