I have often wondered how ancients discovered gunpowder. I stumbled on a site
describing early methods of improving tinder for starting fires, by mixing poor tinder
with urine, feces, and ashes from woodfires. Potassium nitrate would be formed,
and maybe even some cellulose nitrate. In any event they learned how to make
a much improved tinder. There are many places near volcanoes where pure sulfur
can be obtained. The ancients might well have seen sulfur burn, and tried adding
it to their tinder, and suddenly get a surprisingly vicious ignition.
"Besides selecting their raw materials carefully, the ancients learned to
improve on nature by saturating the tinder with blood and urine ,mixed
with potash-rich ashes. Later, this slow biological action was speeded
up in 'nitre beds' - the waste and plant ashes were heaped up together,
exposed to the air and watered at intervals. Eventually after the piles had
been turned many times, this manure produced saltpetre. "
