The Dawson news. (Dawson, Ga.) 1889-current, 1903-06-03
STATE CHEMISTS TALK
a Treatise on Agricultural
Chemistry.
INTERESTING RESUME.
potash-lts Importance as a Plant
Food; Sources From Which DerIVee'
Wood Ashes--Stassfust Deposits.
Nv JouxM McCANDLEss, State Chemist.


BY JOHN M. MoCANDLEss, State Chemist
The only source of potash known
10 our fathers was ashes, mainly wood
ashes, and while potash from this
source is most excellent manure,
vet evidently the quantity available
must be quite limited. The great
majority of soils, especially those
which contain much clay, usually hold
a large reserve of potash, and do not
appear to require the special applica'
tion of potash as a manure. Light
sandy soils on the other hand, and
some clay soils also appear to be quite
deficient in potash and are much bene
Hted by applications of that fertilizer
Soils of this nature, therefore, stand
as much in need of constant potash ma
nuring as of phosphoric acid and nj
trogen applications.
Wood ashes. whilst they may be
cheap and easily obtained in countries
where large forest areas are to be
cleared, in older countries cannot be
so easily obtained Long before fer
tilizers became a commercial commod'
Sty wood ashes were highly thought
If by farmers. But usually when a
Farmer buys ashes he buys in the
dark, owing to the fact that ashes
vary SO widely in their contents OF
potash. AS a rule, ashes from hard
woods are richer in potash than those
From soft woods The ash of the red
oak for instance contains about 6 per
cent of potash that of the hickory
about 8 per cent, some pine woods
about Az per cent. No definite per-
centage however, can be laid down for
any special wood, as the same wood
will vary in different localities, and
the wood of different parts of the
same tree will vary, the ashes from
the twigs and young limbs being rich
er in potash than the ashes from the
body or trunk Of the tree.
1t Is impossible to fix the value OF
u lot of ashes, except by special analy'
sis of the particular lot. owing to this
great variability in composition, and
owing to the further fact that the
ashes may have been leached or mixed
with more or less dirt. The average
analysis for good unleached ashes may
De taken as per cent of potash, 11a
ger cent of phosphoric acid, and 1924
per cent of lime. According to the
values for fertilizers adopted for the
present season, ton of good average
ashes at the coast should be worth
four dollars and fifteen cents. This
calculation allows no value to the lime,
although of course it has decided val
ne on such soils as are deficient in it.
luckily since the middle of the last
century farmers have eeen no longer
compelled to rely on ashes as a source
of potash but have come to adopt in
9heir stead almost universally what
are known as the German or Stassfurt
potash salts.
These salts are mined in Stassfurt
IN northern Germany, in the province
of Saxony. They were discovered by
The Prussian government while boring
For rock salt about the year 1857. At
drst they were considered worthless,
out soon the great Chemist Liebig
began publishing his discoveries con
corning plant growth and nutrition,
showing potash to be an essential and
Znuch-needed element in the growth
and development of plants. This led
70 the development of the potash
mines, and the utilization for agricul'
ture of the precious salts contained in
Ghem The first potash salt works
for the manufacture and sale of the
potash salts was established in Stass.
1urt In 1862. Some of the crude ores
are suited for agricultural use just as
Ehey are dug from the mines, and are