Student suspended for sketching gun

[Amianthus]

how does one get saltpeter out of manure/urine?
 
I read one process of piling it in a hole but i couldn`t get much detail beyound that

Historically, nitre-beds were prepared by mixing manure with either mortar or wood ashes, common earth and organic materials such as straw to give porosity to a compost pile typically 1.5 metres high by 2 metres wide by 5 metres long. The heap was usually under a cover from the rain, kept moist with urine, turned often to accelerate the decomposition and leached with water after approximately one year. The liquid containing various nitrates was then converted with wood ashes to potassium nitrates, crystallised and refined for use in gunpowder.

In more rural times, urine was collected and used in the manufacture of gunpowder. Stale urine was filtered through a barrel full of straw and allowed to continue to sour for a year or more. After this period of time, water was used to wash the resulting chemical salts from the straw. This slurry was filtered through wood ashes and allowed to dry in the sun. Saltpetre crystals were then collected and added to brimstone and charcoal to create black powder.

Potassium nitrate could also be harvested from accumulations of bat guano in caves. This was the traditional method used in Laos for the manufacture of gunpowder for Bang Fai rockets.

During the 19th century and until around World War I, potassium nitrate was produced on an industrial scale from the deposits of sodium nitrate (NaNO₃, nitratine) in the Chilean deserts.This source of nitrates was replaced by synthetically produced nitrates, first by the Birkeland-Eyde process in 1905, and then later from ammonium produced by the much more efficient Haber process. The latter process came online during World War I, and supplied Germany with nitrates critical for the warfare that it otherwise had no access to the deposits of natural nitrate in Chile. It is assumed that this prolonged World War I. Today practically all nitrates are produced by ammonia from the Haber process.
http://en.wikipedia.org/wiki/Potassium_nitrate

[yellow_crane]

On a more germaine level, and just considering creating compost for your garden, the key to good compost, and fast compost, is daily turning with a spade, or if you are doing it in micro supply, in a little tub that turns it for you.  The idea is to expose it to air. 

Most people sclunk a bed and leave it, wondering why it took so long.