> I seem to recall urine can be part of an explosive mixture (ammonia or
> would it be urea?), but then so can compressed sugar or custard powder
> (one General Foods facility in the UK lost a large section of wall due
> to compressed custard powder exploding in the 1980's. The custard was
> definitely for the Birds).

Urine is "rotted" with suitable reactants (straw and other organic
matter) to produce Potassium Nitrate.
Droppings from bat caves and earth floors from mediaeval homes were
good starting materials. In the latter case the gunpowder balifs were
authorised as of right to come and dig up your urine soaked floors and
take them away for processing.

The mixture was typically piled in suitably shaped heaps with a side
exposed at an angle to the prevailing winds. The heap was watered and
the wind dried one side causing net water flow across the heap.
Saltpetre crystals grow on the wind dried side and the material is
scraped off and taken away for processing. More urine mixture is added
on the non wind side and the heap crawls sideways (possibly for more
than wind and scrape reasons alone ;-) ) with time.

Ceratin Saharan bushes are rich in ammonium Chloride. When burned for
fuel these leave (white?) deposits of AC on the inside of chimneys.
Mixing this with Pot Nitrate from the dung heap yields Ammonium
Nitrate. For extra points you can electrolyse salt water to get Sodium
Chlorate. If you use suitable electrodes you can drive the reaction
through to Sodium Perchlorate which is much miuch much safer. Mix the
Chlorate or Perchlorate with the Pot Nitrate from your dung heap and
chimney and you get Ammonium Chlorate or Ammonium Perchlorate. With
suitable skill and experience.

Suitable tree sap (Hevea Brasiliensis) or synthetic equivalents* and
some rust and some suitably powdered aluminium gets you propellant for
the STS aka Space Shuttle solid rocket boosters. (Rust is a rate
catalyst and the aluminum adds nicely to propellant energy.) But, they
don't usually start with urine these days.

* Synthetic equivalent is Buty Rubber which is made from butadiene
which can be made from amyl alcohol which can be made from fusel
alcohol which can be made from potatos, mede, cider and similar.

So if you really really really wanted to, you could go to space
starting with urine, straw, saharn bushes, salt, rust and potatoes.
Plus a very large amount of experience, skill and luck. Which,
essentially, with essentially unimportant variations, is in fact how
it's still done. And, luck is still a significant part of the process.

ustard and other powder explosions usually work by creating an
atmospeher of supended particles mixed with air in such a manner as to
encourage propogation of a high velocity flame front. Also happens
with wheat dust and similar in grain elevators and you can reproduce
the effect with flour, a large press fit ldided tin and a candle**.
It's essentially impossible to go to space using custard powder in
this manner.


        Russell

** YMMV. Try this at home only with due care. Hard to make it work
very well, in my long ago experience.
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