From Gunpowder to Teeth Whitener: The Science Behind Historic Uses of Urine
The saying goes that one person’s waste is another’s treasure. For those scientists who study urine the saying is quite literal–pee is a treasure-trove of scientific potential. It can now be used as a source of electric power. Urine-eating bacteria can create a strong enough current to power a cell phone. Medicines derived from urine can help treat infertility and fight symptoms of menopause. Stem cells harvested from urine have been reprogrammed into neurons and even used to grow human teeth.
For modern scientists, the golden liquid can be, well, liquid gold. But a quick look back in history shows that urine has always been important to scientific and industrial advancement, so much so that the ancient Romans not only sold pee collected from public urinals, but those who traded in urine had to pay a tax. So what about pee did preindustrial humans find so valuable? Here are a few examples: