wrote:
In article .com,
Farooq W wrote:

Dan wrote:
Soil and Dirt particles?! Is that a scientific analysis? Contaminated?
Do you see many pure celulose trees?

Ideally, you should get CO2 and H2O, but nothing's ideal. You don't get
enough Oxygen to get such efficient burning, so, you get a lot of
charcoal (near pure carbon), as well as lots of other stuff like
nitrates and salts that are absorbed from the soil.

We know this because ash used to be the main source of nitrates

I strongly doubt that. Nitrates would not survive high temperatues (of
burning wood) especially in the presence of organic matter. Wood ash is
indeed rich in what we call as
pot-ash and hence the name potassium.

Yeah. The potassium nitrate for gunpowder came from under old
manure piles. Potash was used for making soap, historically, since
wood ash was more accessible than lye before industrial chmistry.

An analysis of Oak/Beech/Bracken tree ash was published Archaeometry
Volume 47 Page 781 - November 2005. The results for Oak tree ash:

This article is available online (free) at

http://www.blackwell-synergy.com/doi...4.2005.00232.x

%
SiO2- 14.62
TiO2 - 0.06
Al2O3 - 0.76
Fe2O3- 0.65
MnO 6.35
MgO 6.87
CaO 31.06
Na2O 0.40
K2O 18.80
P2O5 12.87
SO3 1.09

This much is reasonable -- I'd expect high K and Ca, but the P and Si
are a bit of a surprise. I suspect the Si came from the bracken, since
some ferns (and notably the non-fern horsetail (Equisetum) concentrate
silica, or perhaps it's from dirt. Maybe that explains the high P, too.
While wood ash is an excellent source of K, it usually regarded as only
a moderate source of P, for fertilizer. Non-woody material is higher
in P, Mg and other elements important to plant nutrition.

Not sure what Archaeometry is, but if it's analysis of ancient materials,
the high silica may be due to infiltration from the soil, an early stage
in fossilization. If these numbers come from the residue from an ancient
forest fire, it would explain the higher levels of plant nutrients, since
a lot of live green material would have been included.

Co 15.5
Ni 75.7
Cu 178.5
Zn 2112.4
Ge 3.0
As 1.9
Se 1.3
Br 3.4
Rb 107.9
Sr 533.6
Y 3.0
Zr 41.6
Nb 1.6
Mo 6.5
Ag 1.0
Sn 7.5
Ba 3560.3
Pb 46.1
Th 0.4
U 4.7

I suspect these are in ppt or more likely ppm, rather than %, or we'd be
giving up mining in favor of forestry.

My fault... Its ppm for entries below SO3. More surprising the uptake
of heavy metals especially Th and U by the plants...Barium is
abnormally high or the soil on which that tree grew was rich in barium
ores!

The amounts of these trace
elements probably vary a lot with the composition of the soil in which
the plants grew.