E A R T II. 
177 
fl ame , or take fire. Woodward .—This world oppofed to 
other fcenes of exigence : 
What are tliefe. 
So wither’d, and fo wild in their attire, 
That look not like th’ inhabitants o’ th’ earth. 
And yet are on’t ? Shakefpeare. 
The inhabitants o-f the earth.—The whole earth was of 
one language, Gen. xi. i.—Country ; diftinct region : 
In ten fet battles have we driven back 
Thefe heathen Saxons, and regain’d our earth, 
As earth recovers from the ebbing tide. Dryden. 
The aft c-f turning tip the ground in tillage, [trout ear, 
to plow. ] 
Such land as ye break up for barley to fow, 
Two earths, at the lead, ere ye fow it, bellow. Tujer. 
To EARTH, v. a. To hide in earth.—The fox is earth¬ 
ed-, but I fit all fend my two terriers in after him. Dry- 
d e i _To cover with earth .—Earth up with frelh mould 
the roots of thofe auriculas which the frofi may have un¬ 
covered. Evelyn. 
To EARTH, v. a. To retire under ground : 
Hence foxes earth’d, and wolves abhorr’d the day, 
And hungry churls enfnar’d the nightly prey. Tickcl. 
For the natural hillory and habitudes of ,the different 
earths, ores, Hones, and other fubftances, of which our 
globe appears to. be compounded, as far as at prcjcnt 
known, fee the articles Chemistry and Mineralogy'. 
For the magnitude, rfiotion, figure, denfity, magnetifm, 
feafons, and other phenomena, of the Earth, eonfidered as 
a planet; with the theories of Defcartes, Burnet, Steno, 
Woodward, Whifton, and Buffon, as to its primordial 
and prefeat date; fee the article Astronomy, vol. ii. 
p. 361—370. 
But the “ Theories of the Earth,” erected by_ the 
above-mentioned able philofophers, having, in many re- 
fpefts, been found defective, later writers have endea¬ 
voured to fatisfy inquifitive minds on this important fub- 
jedt, by propofing feveral new hypothefes, lupported by 
great depth of relearch, and equal learning and ability. 
The fir ft who ventured on this devious ground, is Dr. 
James'Hutton, who publiftied his New Theory of the 
Earth, in the firft volume of the Philofophical Tranfac- 
tions of the Royal Society of Edinburgh. This theory 
loon attraCred the notice of other ingenious men, and be¬ 
came a fubjeft of the mod interefting inveftigation. Dr. 
Hutton’s fyftem may be comprifcd under four general 
propofitions : ill. That our prefent continents, rocks, 
and ftrata, have been formed by fubiidence, under the 
waters of a former ocean, from the decay of a former 
earth, carried down to the fea by land-floods, torrents, 
and tempefts. 2d. That the ftrata formed at the bottom 
of the ocean are brought into fufion, and confolidated, 
by fubterraneous fire. 3d. That the ftrata, thus melted 
and confolidated under the waters of the ocean, are forced 
up by fubterraneous fire, to form new continents, moun¬ 
tains, and iflands. 4th. That the three foregoing ope¬ 
rations of nature, viz. the wafte of the old land, the for¬ 
mation of new under the ocean, and the elevation of the 
ftrata thus forming under the waters for future dry land, 
are a progreftive work of nature, which always did, and 
always will, go on forming world after world in perpe¬ 
tual fucceftion. 
The firft who lias ventured to combat this theory, is 
the learned and ingenious M. de Luc. This able philofo- 
pher lias alfo propofed a theory of his own ; nearly the 
lame in principle with that of Dr. Hutton, but extremely 
different in its mode of operation. Both the theories 
have been clofely inveftigated and compared, in letters 
from M. de Luc to Dr. Hutton, publiftied in the Month¬ 
ly Review, and commencing June 10, 1790.'And as this 
correfpondence develops a confiderable portion of new 
and interefting information in geology, we think it right 
to prefent our readers w ith the fubliance of it, in M. de 
Vol. VI1 No. 340. 
Luc’s own words, who addreftes Dr. Hutton as follows: 
“ We fet out, on botli Tides, from this indubitable fact; 
that our continents have been once th c bottom of the fea.: 
which is the grand phenomenon to be explained in a 
Theory of the Earth. Yours is 00 mpofpd oir three funda- 
• mental hypothefes: ift. That no feljijQlratumfbf the earth 
can have been formed, but by its fubftance .having been 
firft melted, and then cooled. 2d. That the fame heat, by 
which our firata have been melted, has railed them above 
the level of the fea. 3d. That new continents, fimilur to 
ours, are now forming at the bottom of the ocean, of t|ie . 
materials of the prefent ones, as thefe have been formed 
of the materials of former continents ; and that the conti¬ 
nents now forming, will rile alfo, when ours lhall be en¬ 
tirely wafed. 
1 ft Hyp. No fiolid firahnn of the earth, can have been 
formed, hut by its Jubfance having been firfi melted, and then 
cooled. —The prefent difquifttion having Jo/ids for its ob¬ 
ject, I mull premife what I underhand by Jhlidity. 1 de¬ 
fine a jolid, a body wliofe condiment parts, have been 
brought, by whatfoever catife, into-fo clofe a contact, 
that they remain united by cohefion ; the caufe of which 
is not our objett. Two principal caijfes may bring in¬ 
coherent particles into clofe contaa ; either fufion, or the me¬ 
dium of a liquid-, but the final effeift is the fame ; the par¬ 
ticles adhere to one another by cohefion. You mention both 
thefe cauies; but you fix excluliveiy on the firft. Now, 
fiolids fornled by thefe two different mediate cauies, rnull 
have different charafters; and from thefe we may firft 
determine which of the two caufes has confolidated our 
firata. The diftkiftive characters of Jo lids produced by 
fufion are, that fuch fiolids may be melted again by mere 
heat-, and that, after cooling, they (lull be the (arife, or 
nearly fo, as before: but of all the fiolidfirata of our con¬ 
tinents, lavas only are of that nature ; confequentlyj^r.Qne 
of the other ftrata have been melted. The fame conclulion 
may be drawn from a more remote theory. Fufion is an 
operation of fire, by which a liquid is produced of fub¬ 
ftances which, before, were not in that Hate: but the 
procefs of liquefiaElion is very different, when fubftances 
have been already melted, from what it is when they have 
not; and from that difference, we may alfo judge your 
hypothefis, by premifing fome principles. A liquid, is a 
fubftance compofed of homogeneous particles, either fim- 
plc or mixed-, which particles are in a certain combination 
with fire , from which refult thefe two charadleriitic pro¬ 
perties ; that the condiment particles of fuch fubftances 
have but very little adherence together; but that, how¬ 
ever, they have a tendency towards one another at a fen- 
fible difiance. It is from the firft of thefe properties, that 
particles of liquids fubmit fo readily to the law of gravi¬ 
tation in their mafs itfelf, fo that their furface is always 
horizontal; and from the latter, that the fmall maftes of 
liquids tend to aflurne a fpherical form. Now', from thefe 
properties alfo it is, that a liquid confolidates by a certain 
degree of cooling ; and that the fiolid produced has a pe¬ 
culiar character. For, while the fubftance was liquid , 
its condiment particles, from their tendency to one ano¬ 
ther, were come to the clofeft poftible contabl ; without 
yet adhering, becaufe of their combination with fire : but 
when that combination ceafes by a fufficient degree of 
cooling, their adheficn inftantly takes place. 
Let us now examine, from thefe principles, what mult 
be the procefles of fufion, in the two claftes of fiolids above 
diftinguifhed. Fragments or powders of fubftances which 
have been already melted, are immediately liquefied again 
by a fufficient degree of heat ; their condiment particles 
having been brought before to homogeneity and to the 
faculty of combining immediately with fire-, from which, 
when they cool, they produce fiolids fimilar to thofe 
which have been melted: but the cafe is very different' 
with fiolids which are known to be produced by > oAir 
caufes than fufion - as for inltance, mortar, concretion. o*riade 
by fome waters, the Jolid parts of animals and vegflbles, 
beftdes many others controverted between us. Cofufiou, 
or its modification called affinity , is alio the immediat 
Z .a; «au& 
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Jt 
