The history of human waste is surprisingly full of practical applications in everyday life. Urine, feces, and blood served as commodities like anything else during different eras, and humans found ways to put waste to good use. There are plenty of unexplained ancient discoveries confusing to historians, but some ancient applications of human waste were downright ingenious.
Uses for human poop ranged from medicinal to military, while urine had industrial and practical applications galore. Though some people misunderstood a variety of ancient things, especially about the human body, this didn't stop other outside-the-box thinkers from finding a use for all their crap just sitting around in chamber pots.
In 12th-century China, fighters developed a powerful weapon which combined human feces, as well as other waste, poison, and gunpowder; the warriors would then hurl the end product at their enemies. They heated the concoction, placed it in ceramic containers, and sent these flying from trebuchets.
Once the bomb hit its target - be it a building or a group of soldiers - the contents would form a noxious cloud. The unpleasantness of the poop-poison not only humiliated the enemy, but spread life-threatening contagions as well.
The ancient Roman historian Pliny the Elder wrote about how some considered urine a remedy for removing ink spots. Modern household cleaners often contain ammonia to dissolve clumps of dirt or grease, and urine turned out to serve as a natural, renewable source of ammonia for Roman cities.
Roman citizens would urinate into designated vessels on the street. When the tubs were full, they would take the vessels to the fullonica (laundry), then watered down the solution to pour over dirty clothes.
Urine was also essential in the tanning process. In ancient and medieval times, tanners soaked animal hides in lye and urine to loosen the skin and remove hair. From there, they would soften the leather further by beating an animal-dung paste into it or giving it a soak in animal-brain solution.
The Vikings easily adapted to their surroundings - when it came to starting fires, they found ways to use their urine as a valuable commodity. Vikings would gather a specific type of fungus called touchwood from oak and beech trees, and boil it in their urine for several days.
After hammering the boiled fungus, the result was a natural fire-starter that's so rich in sodium-nitrate, it could smolder for days. To start a fire, Vikings only had to blow on the sodium-nitrate cloth to transform a smolder into a flickering starter flame.
Scythian archers famously owned some of the most fearsome weapons in ancient combat. Their arrowheads were aerodynamic and their bows powerful, but the poisons they used were the most devastating. In addition to various snake venoms collected during the nomadic warriors' travels through central Eurasia, they used human excrement and vital fluids to increase their arrows' deadliness.
They combined feces and blood, buried the mixture until it putrefied, then added venom and decomposing viper remains. Lastly, they dipped their arrowheads in the biochemical concoction. When the arrows struck their enemies, the human waste and blood mix led to tetanus and gangrene, while the poison exacerbated the situation. The infected wounds could prove fatal within days.