6 Historic Uses Of Urine

1) Tanning leather. Urine is full of urea, which degrades into ammonia. Ammonia high pH breaks down organic material, making urine the perfect substance for ancients to use in softening and tanning animal hides. Soaking animal skins in urine also made it easier for leather workers to remove hair and bits of flesh from the skin.

2) Cleaning and whitening clothes. The ammonia removes stains and intensifies the colors of dyes.

3) Gunpowder. Urine can be used to make saltpetre, a key ingredient of the explosive.

4) Tooth Whitener. Again, from the ammonia.

5) Urine was also used as a health supplement (Gandhi would drink his own every morning and Madonna has claimed that she used it to cure her athlete's foot).

6) Urine was also used to recover phosphorus, as explained by Tree Hugger in PeeCycling: Make Phosphorus From your Own Pee.

Source: http://www.treehugger.com/cleaning-organizing/urine-surprise-6-historic-uses-pee.html