In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash is the non-gaseous, non-liquid residue after complete combustion.
Ash occurs naturally from any fire that burns vegetation, and may disperse in the soil to fertilise it, or clump under it for long enough to carbonise into coal.
There is twice as much phosphoric acid in the European aspen than in oaks and twice as much magnesium in elm trees than in the Scotch pine.
While often referred to as ashes, the remains primarily consist of powdered bone fragments due to the cremation process, which eliminates the body's organic materials.
[8] People often store these ashes in containers like urns, although they are also sometimes buried or scattered in specific locations.
[4] This process can be used to measure minerals like calcium, sodium, potassium, and phosphorus as well as metal content such as lead, mercury, cadmium, and aluminum.
Analysis of the contents of ash samples from Vietnam[10] and Singapore[11] shows that joss paper burning can emit many pollutants detrimental to air quality.
There is a significant amount of heavy metals in the dust fume and bottom ash, e.g., aluminium, iron, manganese, copper, lead, zinc and cadmium.
"[12] High levels of heavy metals, including lead, arsenic, cadmium, and copper were found in the ash debris following the 2007 Californian wildfires.
They are the main fertilizer in slash-and-burn agriculture, which eventually evolved into controlled burn and forest clearing practices.
People in ancient history already possessed extensive knowledge of the nutrients produced by (from social 10th textbook)(manufacturing industries )different ashes.
The demand for organic products has led to renewed interest for laundry using ash derived from wood.