Ancient 'urine flasks' for smelling (and tasting) pee uncovered in trash dump at Caesar's forum in Rome

A Renaissance-era trash dump discovered inside the Forum of Caesar in Rome is brimming with old medical supplies, including 500-year-old medicine bottles and urine flasks — containers used to collect patients' pee for medical analysis, a new study finds. 

Initially excavated in 2021, the 16th-century medical waste dump was found in the area of Caesar's Forum, which was completed in 46 B.C. and dedicated to Julius Caesar. But a millennium and a half later, a guild of bakers used the exact same space to build the Ospedale dei Fornari (opens in new tab) (Bakers' Hospital). The hospital's workers then created the dump, according to the study, published April 11 of the journal Antiquity (opens in new tab).

During their work, archaeologists with the international collaboration Caesar's Forum Excavation Project (opens in new tab) discovered a Renaissance-era cistern full of ceramic vessels, rosary beads, broken glass jars and personal items like coins and a ceramic camel figurine. Many of the objects, they suggest, were related to routine patient care at the Ospedale dei Fornari, with each person admitted to the hospital given their own "welcome basket" with a jug, drinking glass, bowl and plate as a hygienic measure.

More than half of the glass vessels recovered from the dump are likely what medieval Latin medical texts call matula — urine flasks (opens in new tab). During the Middle Ages and Renaissance, the practice of uroscopy was a central diagnostic tool for physicians. 

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Fragments of glass urine flasks excavated from the cistern. (Image credit: Sovrintendenza Capitolina — The Caesar's Forum Project)

"The patient's urine would be poured into a flask to allow a doctor to observe its color, sedimentation, smell, and sometimes even taste," project directors Rubina Raja (opens in new tab), Jan Kindberg Jacobsen (opens in new tab), Claudio Parisi Presicce (opens in new tab) and colleagues write in the study. Such analyses could shed light on whether patients had conditions such as jaundice, kidney disease or even diabetes, as diabetics' urine often smells and tastes sweet due to extra glucose. 

Urine flasks are tough to identify in archaeological contexts because their shape is similar to oil lamps, and they are rare in contexts other than hospital dumps. 

A final group of objects from the cistern included lead clamps from furniture fittings associated with carbonized wood, or wood treated with fire. These objects may be evidence of a historically known hygienic measure: the burning of objects from houses with plague cases, as written about in 1588 by Quinto Tiberio Angelerio, an Italian physician who published a series of rules (opens in new tab) for preventing the spread of disease.

Once full, the cistern was capped by a layer of clay, likely for hygienic reasons, the authors write. While landfills existed at this time outside the city walls of Rome, "the deposition of waste in cellars, courtyards, and cisterns, although prohibited, was a common practice," study lead author Cristina Boschetti (opens in new tab), an archaeologist at Aarhus University in Denmark, told Live Science. In this case, the cistern may have been selected as a place suitable for sealing infectious waste, Boschetti explained.

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Monica H. Green (opens in new tab), a medical historian and independent scholar, told Live Science in an email that she agrees with the interpretation that the dump belonged to a hospital based on its "bespoke ceramicware." 

Although we know today about the benefits of cooking or boiling glass to sterilize it, "people did not know the effects of sterilization at the time," Boschetti said. "They must have known that at least some kinds of glass could withstand cooking or boiling," Green agreed, but "that doesn't mean they nevertheless thought in terms of 'sterilization'."

While the medical dump found in the Forum of Caesar is actually the second example of hygienic disposal practices related to the Ospedale dei Fornari, little archaeological attention has been directed at other Renaissance-era hospital and medical contexts. The authors conclude that their study greatly helps our understanding of past practices "while highlighting the need for a more complete overview of the hygiene and disease control regimes of early modern Europe."