It was guano that was used for gunpowder, and just guessing here, it was the urine, since ammonia (a nitrogen based compound) is a by product of oxidated urine.
as pointed out before, (thank you Dr.bill!) birds urine which is white, contains a different compound of urine, than most other animals. maybe that is what makes the difference..

crossing thread, i learned all of my organic chemistry from issac asimov's World of Carbon and World of Nitrogen-- two excellent books that are easily readable, and make chemistry fun!( but since there were no labs-- i find i have to go back and read the volumes again every once in a while. i don't do organic chemistry, and the detail blur with time.)


my other obsession