From Roman toothpaste to gunpowder production, discover the shocking ways our ancestors put human and animal waste to work
Human and animal waste once played surprisingly important roles in medicine, industry, and daily life. Here are ten of the most bizarre historical uses that might make you grateful for modern science.
1. Roman teeth whitening
Ancient Romans discovered that urine could brighten their smiles, thanks to the ammonia it contains. Urine was such a popular tooth-cleaning agent that it became a commercial product. The practice was so common that the poet Catullus wrote mocking verses about Spaniards who brushed their teeth with urine. Public urinals collected the liquid, which was sold to fullers and those seeking a brighter smile. The practice persisted in some form until the 18th century in certain European regions.
2. Medieval diagnostic tasting
Medieval physicians took uroscopy to an extreme level that would horrify modern doctors. They didn’t just examine urine’s color and clarity—they tasted it. Physicians believed they could diagnose conditions like diabetes by detecting sweetness in urine, which actually had some scientific basis. However, they also claimed to identify dozens of other ailments through taste, smell, and visual inspection, consulting elaborate urine color charts that supposedly revealed everything from liver problems to lovesickness.
3. Egyptian crocodile dung contraception
Ancient Egyptian women used crocodile dung as a contraceptive barrier. They would mix the dried, powdered excrement with other substances to create a paste inserted before intercourse. While this sounds purely superstitious, the alkaline nature of the dung may have actually had some spermicidal effect. The practice appears in the Kahun Papyrus, one of the oldest medical documents in existence, and elephant dung served a similar purpose in other cultures.
4. Gunpowder from waste
For centuries, human and animal urine and feces were essential to warfare. Waste was composted in special beds called nitre beds to produce saltpeter, a key ingredient in gunpowder. During the American Civil War, both the Union and Confederacy issued instructions for citizens to save chamber pot contents and stable sweepings for the war effort. The Confederacy even had official agents who would scrape the dirt floors of barns and outhouses to extract precious nitrates.
5. Renaissance hair loss remedies
As the article about Bartholomäus Vogtherr’s medical manuals revealed, Renaissance Europeans believed that rubbing human feces on the scalp daily could cure baldness. Various recipes called for mixing the excrement with other ingredients, and the recent proteomics study confirmed that people actually followed through with these treatments. The logic was based on ancient humoral theory, which held that waste products could balance the body’s fluids.
6. Textile industry foundation
The ancient Roman textile industry couldn’t function without urine. Fullers, who cleaned and processed wool cloth, needed vast quantities of the stuff. They set up public urinals throughout Roman cities and actually paid taxes on the urine they collected. The ammonia broke down the grease in wool and helped set dyes more permanently. Emperor Vespasian even defended the urine tax when his son complained, reportedly saying that money doesn’t smell. Workers would stomp on cloth soaked in urine to clean it, a process that continued in various forms through the medieval period.
7. Wound treatment across civilizations
Multiple ancient cultures applied animal dung to wounds, burns, and skin infections. The Ebers Papyrus from ancient Egypt contains numerous recipes mixing crocodile, pelican, or gazelle dung with other ingredients for poultices. Greeks and Romans followed similar practices. While this seems dangerously unsanitary by modern standards, some researchers have suggested that certain molds growing on herbivore dung might have provided antibiotic effects similar to penicillin, though this remains debated.
8. Tanning leather
Dog feces, known as “pure” to tanners, were particularly prized in leather production. Tanners would work the excrement into animal hides during the bating process, which helped soften the leather and remove remaining hair. The enzymes in the waste broke down proteins in the hide. Children in medieval Europe could earn money by collecting dog droppings from the streets to sell to tanneries. The smell of this process was so overwhelming that tanneries were typically relegated to the outskirts of towns.
9. Cosmetic face masks
Wealthy Romans and later Europeans used various animal dungs in beauty treatments. Nightingale droppings, mixed into a paste, were applied as a facial treatment believed to brighten and soften skin. This practice actually persisted in Japan through the modern era, where geishas used nightingale droppings to remove their heavy white makeup. Bird droppings contain guanine, which does have skin-lightening properties, giving this bizarre practice a grain of scientific validity.
10. Viking Age fuel and fire starters
Vikings and medieval northern Europeans collected dried cattle and sheep dung as a crucial fuel source in regions where wood was scarce. Beyond heating, they discovered that fabric soaked in urine and dried made excellent fire-starting tinder. The nitrates in the urine-soaked material would catch sparks readily and smolder for long periods, allowing people to transport fire more easily. Mushrooms soaked in urine served similar purposes, with the tinder fungus becoming especially valued for its long, slow burn.
The end of an Era
These practices declined as scientific understanding advanced during the Enlightenment and Industrial Revolution. The germ theory of disease in the 19th century finally put an end to most medical uses of waste, while chemical manufacturing provided alternatives for industrial applications.
Today, these historical uses of urine and feces seem bizarre and unsanitary, yet they reveal human ingenuity in making use of every available resource. While we shouldn’t romanticize the past or its questionable hygiene practices, understanding these customs gives us perspective on how far medicine and science have progressed.