I should be more careful. I've been pissing this stuff away my entire life!
https://en.wikipedia.org/wiki/Phosphorus#Discovery
which is funny considering that economists and such are worried that mining phosphorus rock might have a limit soon:
One of the more entertaining episodes in Don Quijote is when he and Sancho are confused by the persistent loud noise made by the hammers in a fulling mill.
I wonder whether urea is recovered from waste water at water treatment plants.