The Cecil Whig. [volume] (Elkton, Md.) 1841-current, 1851-02-22
Tte farmer.
AGRICULTURAL GEOLOGY.
BY JOSIAH HOLBROOk,
Ne, 4,

It's varieties. il is almost the entire Gle
ment; of ieldspar, ii is the principals: al.
luminous or clay soils contain frequent
ly twice as much slick rs .alumina: The
quantity ofiron and potash in frl,|spal
is small, not often over two or three PEI
cent.
1t appears then that sand is composed
Of two oXydrs or chemical combinations
again combined by the same agency.
Feldspar or clay is composed of four OK
ydea, also combined by chemical aiiini-
ty, to form 4 compound still more com
pick than quartz or sand. The quartz
and teldspar are. combined bya mrchan-
ical mixture to form rocks and soils.
1t hence follows, that in these two cl-
emcnts Of so;lS, quartz and teldspar, or
sand and clay, are not less than six COM
blnations Of ultimate principles, or OK
ygen and metals, all by chemical afin-
ity, and two combinations at least of
those compound forming those two cle-
ments. These six chemical compounds
again compounded by chemical agency,
are then united by mechanical mixtures
TO form rocks and soils.
Quartz and tcldspar are not only the
essential elements of soils, but also
among the most Important materials in
the arts Of civilization. The princij al
material of glass is quartz; that OF por-
celain, irld$par. The presence of pot
ash, soda, or some alkaline substance
acting as Nuy, is indispensable in the
manufacturing Of each of these import
ant articles ofdomestic economy.
After performing the important agcn-
cy OF producing vegctation-of course
furnishing our wheat, our corn, our beef,
and our pork-quartz of a porous char
acter constitutes the French burr, for
changing grains into flour. Pu!vrrizrd
quartz, cemcntcd by iron into sandstone,
forms our grindytcncs, for sharpening
the axes and chisels of the mechanic
and the knives and scissors fthe house
keeper. For some animals it is essen
tial to the process Of digestion; fowls
cannot live without it.
Everything. animate and inanimate:
every product of nature and Of art; eve
ry human being in every position and
condition Of iilc-thc sturdy farmer.
the busy mechanic, the industrious
housekoeper, the delicate refined lady,
tn" polished gentleman, the enlightened
TEACHER, the wise statesman, and the moi
sy politician: in a word, everything
which has physical existence bears visi-
BILE testimony to the necessity of this
important element of mountains, rocks,
and soils-of quartz, sand--''a common
Stoaa,'
Experiment: Shake tumbler, con-
tanning little newIy-slaked lime and
some water: LET the tumbler stand till
the lime settles and the water becomes
clear; pour tie water into another tuln-
bier and blow into if air from the lungs
through gull or pipe-stcm, the clear
water becomes turbid with white flakes
or sediment, by the carbonic acid
from the lungs uniting with the lime
IN the water forming the carbonate of
lime.
Mica is a compound Of DIVIDES, more
compounded than either quartz or field
spar. 1t contains all the DIVIDES enter.
ln5 INTO both thesn minerals, with the
addition of mdgncs", much used for
bleaching salts, (chloridr Of lime.) Mi
ca also contains traces ofthe silicate of,
magnesla-the articIr used in the manu-
1ac!ure 81 epSom salts and other chemi-
Gals. This silcate, as its namr denotes,
contains slick, Or the OXIDE of silirirm
1t has been found by the progress of re-
ology in large quantities, both in Penn
sylvania and Maryland. From il have
been made various, chemicals, and among
them EPSON salts; (sulpIate Of magnr-
STA, nj so cheap rate, in such quaint
ties, and of so good quality, as entirely
TO supcrscdc the importation Of this arti-
Gle, SO extensively used for medicinal
purposes. In connection with this sill.
cate and other magnetism minerals,
chrome ore (chromate of from has been
found, and chrome yellow, (chromate of
lrad) made from it, with such success as
TO reduce The price Of that valuable paint
from fifteen dollars 10 twenty-five cents
pound, thus bringing the benefits of
geology and chemistry to every indi-
Vldual IN the community at least to
every man and woman who rides in
carriage with yellow paint, aud to every .
child that uses atlas with colorcd maps. |
Mica IS not an important element in
soils, and in rocks is less abundant than
either quartz or feldspar. Though not
abundant in rocks, it is one Of the three
materials Of granite, and has an import
ant inhuenc" in modifying the character
OF rocks IN fitting them both for agri-
cultural and architectural purposes. It .
gives to Snelss and MICA slate, both gran
ite formations, a facility in beng work.
ed into slabs Of greatly extended surface,
fitting them for sidewalks, bridges,
flOOrS firm nnnluSllrnS and nuuanrnuu |