The national era. [volume] (Washington [D.C.]) 1847-1860, 1851-01-02
AGRICULTURAL GEOLOGY.-No. 1.
BY JOSIAH HoLBR0OK.


No class of the community have an equal in
terest in geology with farmers. No science is 30
interesting to farmers as geology, in connection
with chemistry. The two sciences cannot be
separated and Justice done to either. While the
elements of our globe, especially of soils, require
chemical tests to determine their character these
very elements are absolutely essential for expert
ments to determine the fundamental principles of
chemistry. Oxygen, the most powerful chemical
agent in creation is also the most abundant mate
rial N rocks and soils. The one as an element,
the other as an agent, are alike essential to each
other, and both indispensable, as at the founda-
ton of all agricultural science.
A knowledge of each is as feasible as it is i'm
portant-eptirely within the comprehension of q
child six years old. Each is a science Of facts
more than of abstract reasoning-of facts, too,
equally instructive and delightful to every young
mind.
Take an example: The child has placed before
him two glass tumblers--the one containing
quartz, the other lime, or sand and chalk
name Of each ia Of course as readily learnt as the
name of iron, lead gold, tree, horse or any other
object in nature or art. Into each tumbler is
poured some sulphuric or muriatic acid. in the
tumbler of lime the pupil observes an action--in
| that of quartz no action. He is told this action
! is called effervescence. He hence learns to rec.
| ognise lime and quartz, and the more certainly
from the reoolectian that the one effervesces with
acids, and the other does not.
Here is an example Of geology and chemistry
alike useful to the farmer and interesting to tie
farmers child, or any child. The same smpli.
city and direct Fundamental instruction run
through the whole Of both of these exceedingly
practical sciences.
. | may hereafter point out few Of the leading
principles Of these two sciences their connection
with each other; their essential Importance to al
classes and most Of all, farmers their. exceeding
fitness for the early instruction of children, and
| the entire feasibility Of having them among the
" first lessons" taught in each of the eighty thou.
sand American schools.
No2.
Oxus is the Greek word for acid: ginomai, In
! Greek means MAKE; hence the literal meaning OF
oxygen is acid maker. Combined with sulphur il
forms sulphuric acid with nitrogen, nitric acid
with carbon, carbonic acid, &c Respiration, CON-
bustion and fermentation, are the three princp pal
operations producing the combinations of oxygen
and carbon the results, carbonic acid.
Acids combine readily with metals, earths, and
alkalies-as iron, lime, and potash. BY chemists
these combinations called salts, designated by
the termination ate. Sulphurc acid, combining
with various bases, produces sulphates nitric
nitrates; carbonic, carbonates. Sulphate Of lime
| 10 Jfouui1Oi pihotSI VI ouiiu'eo Vi hvh
copperas of soda, glaubcr salts Of maguesia
Epson salts The carbonate Of lime is common
limestone, marbles, chalk, and many beautiful
crystals Carbonates Of iron, copper, and lead
are ores Of those metals.
About a century ago, water was found to bt
composed Of oxygen and hydrogen, and common
air of oxygen and nitrogen About half cen
fury since, oxygen was found by Sir Humphrey
Dayy to be an element Of rocks, Of course Of soils
as it was of the alkalies, potash, and soda. Th'
other elements in earths aud alkalies, oombinet
with oxygen, were found, by the same great chem
is' 10 no ms'ais very rccaiia. in, character.
IL hence appears that oxygen Is an element ID
air, earth, and water, existing abundanty In solid
liquid, and aerial forms. In the whole II consti
tates nearly half Of our globe 1t is, Of course
the most abundant element in the material world
1t is also I'D most important agent in producing
changes in matter essential to human existence
IL is very appropriately called raal ar, as neither
animal life nor any life can exist without it, l,
is no less essential TO combustion than to life II
also acts with great energy upon metals and other
solid substances, n this action it produces three
very large and very important classes of bodies
oxydes, acids, and salts Iron rust is the oxyde
Of iron the dross Of lead, oxyde of lead burnt
lime, the oxyde Of calcium; pure potash the oxyde
Of potassium pure sofa, the oxyde Of sodium
slick, or flint, the oxyde of silicium. The com.
bination OF one part oxygen and four of nitrogen
constitutes the atmosphere three parts oxygen
! and one nitrogen form nitric acid, aquafortis
Combined with other substances, it forms numer.
Gus acids. Satpe,re is the nitrate of potash
The large quantity Of oxygen IL receives from tn,
nitric acid fits II for a material in gunpowder-
giving to that powerful agent its principal power
A plate, tumbler aud scrap of paper, with .
little water will enable any teacher or parent t.
perform an experiment on oxygen equally simple
instructive, and interesting. In deep plate pou,
some water. Ga the water place scrap of thick
paper, piece Of cork, or other light substance OF
that another piece Of paper or cotton, moistenet
with oil On lighting the paper or cotton, plac,
over Ii a large empty tumbler The combustion
continues for a few seconds, and when Il Is extin
guished the water occupies about one-ffth Of tn,
space in the tumbler, showing the necessity o
oxygen for combustion, and that II constitutes
about one-ffth Of the air We breathe. What man
woman, or child would not like 10 be familarly
acquainted with an element so abundant and agen
80 active as oxygen, especially when such an &C
qusintance is equally simple, useful, and de
lightfal2
Nos.
Rocks are the oxydes Of metals. Slick, tn,
most abundant ingredient in rocks, mountains
| and soils, IL the oxyde Of siliciumL This oxyd,