Weekly national intelligencer. [volume] (Washington [D.C.]) 1841-1869, 1852-02-28

condensed and capable OF burning longer and with more
intense heat Tar also dstils over and naptha and
bonc acid gas, and ammonia including collectively the
elements, carbon hydrogen, oxygen and nisogena Of
them organic elements and the nitrogen is known
to be derived from the aIbumen "a principle analogous
the white of egg which is found to be extensively
difused through the vegetable kingdom.
But the vegetable origin of coal proved also by its
sructare, and by the accompanying plants and trses.
We will first mention the principal varieties of caybona
ceous substances found in the mineral kingdom.
Ignite is merely altered wood It does not belong to
the coal formation having derived it's origin from the
trees Of the tertiary period much later era The srac-
tura Of weodybr knots, &C. is frequently in the
Ignite, ahoughit is Of black brown color and 1t
burns not with the tar-ke oor of btuminous COAL but
with the acrd sharp smell of smoke of wood and taects
the eyes in similar In the Ignite amber is
often found having only the turpentne Of the an
cent condensed into solid form by tho escape Of
its volatile oil Ignite is sometimes found in thick BEDS
and y valuable combustible, although its discovery
prelude to COAL and has connexion with pro-
per beds
Great sums of money have been expended in England
and to extent in this country in vain explorations
for coal in beds of Ignite and brown COAL which, well
as jet, is only variety Of Ignite.
The diamond itself is believed by Sir David Brews
ter and other highly qualified judges be of vegetable
origin
We do know of any carbon which is properly min
era clement unless it may be found in pumbago black
tead-a misnomer, since it contains no ead.)
Anthracite differs from bituminous coal only in the
absence of btumen which is the altered turpentne of
the ancient forests.
Bitumen in the form of liquid is called petroleum or
in this country Seneca OIL and appears have resulted
chiefly from the vegetables of the coal formations and in
Western States it frequently rises along with inam
mable gas from the deep borngs for salt water which,
may presume pierce the coal formation its equi
vaent strata.
The gas is the that produces explosions in the
coal mines it arises from the slow fermentation of the
geabe BEDS lying under immense PRESSURE and secluded
from the air The combustble gas (carburetted hydro
gem when mixed with the amosphercal air is rendered
explosive, and, being kndled by naked burning lamp
produces destruction the miners by concussion by
flame, and by resulting atmosphere which is irespra
ble 1t is not that fifty lives destroyed at
once; and mines, Of the anthracite, have
not been exempt from this calamity. The safetylamp of
Sir Humphrey Davy, properly constructed and used,
affords great protection, but STILL destructive explosions
do occasionally The anthracite has probably lost
its bitumen from the effect of internal heat The mines
of Pennsylvania show many marks of violent internal
movements very possibly connected with the operations of
fire.
Coal like that oil PlttSDurgn, hcnmonu, anu Liver
pool btumnous retaining its tar and to great extent
its gas and is therefore highly combusble with abun-
dant bright flame; while the anthracite kndles more
slowly, and burns with little flame and feeble light.
The geological arrangements of the coal formation
generally very simple and similar in all countries where
4 coal is found.
AT the bottom there is commonly stiff tenacious clay
much valued as FIRE clay; then the proper coal; ther
above it shae "a soft imperfect slate formed eyident,
from the ancient mud) and then sandstone. 1t pre-
sens in different cases the varieties of sandstone
puddng-stone and congomerate this having ev
dently arisen from the disntegraton of higher lands
Beds of limestone and of clay iron not uncom-
mon among the coal strata and beneath the entire orma-
ton there is usually powerful bed of limestone called
the carboniferous.
In the clay which forms the basis of the proper coal
measures both the and stumps Of often
found, which, from certain markings upon their roots,
have been called stigmaria.
There also found frequently among the coal strata
distinct impressions upon shales and sand-sones and
even upon the coal ITSELF which the of sigaria
has been given; and the sigmaria and siglaria were
supposed to be distinct but they have been found in
nexon and the former is the root of the latter Other
vegetables which attained the height Of trees are found
in and with the coal The ferns sometimes trees Of
twenty to thirty feet high the equisetacee (calamites
we're thirty forty feet high and six inches in diameter
club-mosses, ground pne) Qepidodendra,) sixty
venty feet high But the greater part Of the beds Of coal
was made up Of smaller vegetables leaves branches &C.
uxuriant and perennial vegetation must have
ed the coal fields constituting matted and inter
woven underground. Many hundred species Of coal
plants have been identified and most Of them
lar cryptogamie and the most abundant plants were
ferns. The coal vegetation has been ascerained to be
substantially the in all countries whore coal found
It would require equal and tropical temperature and
500 added to that the polar circles would give them the
climate Of the equator The most probable cause Of the
warmth Of the coal climate would appear be that the
internal heat of the earth had yet declined its
sent temperature Many facts to be mentioned here
after tending show that the early terrestrial animals
enjoyed higher temperature than that prevailing
Avegetable structure is often observed in the coal itself
bres between its layers often in its fracture
and coal sliced very thin and viewed through the micro
scope exhibits vegetable structure, and sometimes its
cells filed with the prmeval turpentne concretcd in
the manner Of amber or copal The coal vegetation
not fitted to support the life terrestrial animals and
none had as yet been created only reptiles and
amphiba had begun appear, thus forcshadowing the
great change that about TO take place in the animal
world.
The covering Of earthly matter which reposes upon the
coal in the form Of shae and sandstone must have beer
brought by water sometimes perhaps by flooding but
that would not to have been often the fact as tt
leaves OF ferns and other plants which, in the
profusion often entobed in the shales and some
.sn.o, a. tho oandsfo,aa xro,.la :~.-1-