Huh. I thought this was going to be about the pee-collectors in France while they were at war with England.
They'd go around collecting it from chamber-pots, etc, boil it down and re-re-re-crystallize it to make pure saltpeter.
France was a big supplier of powder to the American Colonies during the "unpleasantness" with England.
Didn't read the whole thing, though.
