GEOLOGY. 
numerously on one spot than on another. 
Particular currents may perhaps be consi- 
dered among the causes which assisted in 
producing these effects, as well as in form- 
ing particular chains ; whilst to the action 
of contrary currents may be attributed the 
formation of separate mountains. The for- 
mation of secondary mountains seems also 
to concur with what is generally observed 
in the ordinary progress of crystallization ; 
where it is observed, that after one series 
of crystals are formed of the least soluble 
matters, others are then formed of those 
substances which the fluid was able to hold 
still longer ip solution. It has been ob- 
jected against this system of crystallization 
of rocks, &e. that nature seems to perform 
nothing of that kind at the present period ; 
but were this the fact, the objection would 
not possess much force, since a most satis- 
factory answer might be yielded, by assert- 
ing that the operation has ceased, in conse- 
quence of the task being accomplished ; 
and, speaking with respect to the granitic 
and porphyry rocks, alt the materials being 
employed. The formation of stone by crys- 
tallization is, however, carrying on in va- 
rious situations at the present moment ; 
the incrustations formed in certain springs, 
and the various stalactitic formations which 
take place daily, are instances of this kind. 
The unfitness of water to hold the sub- 
stances forming the primitive rocks in solu- 
tion, has been considered as a powerful ob- 
jection ; but it is to be considered, that the 
menstruum cannot be supposed to have 
been simple water, but, as Mr. Kirwan 
observes, this primitive fluid must have con- 
tained all the various simple saline sub- 
stances and indeed every simple substance, 
variously distributed, “ forming, upon the 
whole, a more complex menstruum than 
any that has since existed, and consequently 
endued with properties very different from 
any with which we have been since ac- 
quainted.” Geological Essays, P. II. 
Considerable difficulty must, however, 
continue in adapting any system which 
confines the production of the various geo- 
logical phenomena which present them- 
selves to our observation to too few and 
to too limited causes ; since however neces- 
sary it may be to refer the general phe- 
nomena to the operation of one particularly 
powerful agent, it still must be neccessary 
to take into the reckoning the sinking and 
the raising of particular spots from sub- 
terraneous submarine fires ; as well as the 
changes produced by the subversion of 
lofty mountains, rapid and violent cur- 
rents of water, and various other powerful 
causes. 
By the preceding sketch of the numerous 
systems which have been advanced, and 
by these cursory remarks on some of the 
objections which have been made against 
those which appear to possess the greatest 
share of probability, the mind becomes bet- 
ter prepared to attend to the system of the 
celebrated Werner, to whom, in the opi- 
nion of his learned and zealous annotator, 
we owe almost every thing that is truly 
valuable in this important branch of know- 
ledge. For the purpose of conveying some 
notion of this ingenious system, the follow- 
ing sketch is taken from the view of it 
given in the “ Elements of Geognosy,” by 
Professor Jameson. 
Agreeable to this system, the earth is 
supposed to have existed originally in a 
state of aqueous fluidity, which is inferred 
from its spheroidal form, and from the high- 
est mountains being composed of rocks, 
possessing a structure exactly resembling 
that of those fossils which have, as it were, 
under the eye, been formed by water. 
From this circumstance it also follows that 
the ocean must have formerly stood very 
high over these mountains ; and as these ap- 
pear to have been formed during the same 
period of time, it follows, that the ocean 
must have formerly covered the whole 
earth at the same time. Contemplating 
the formations of the mountains them- 
selves, Werner discovered the strongest 
proofs of the diminution of the original 
waters of the globe. He ascertained, 1st, 
that the outgoings (the upper extremities 
as they appear at the surface of the earth) 
of the newer strata are generally lower 
than the outgoings of the older, from granite 
downwards to the alluvial depositions, and 
this, not in particular spots, but around the 
whole globe. 2d. That the primitive part 
of the earth is entirely composed of chemi- 
cal precipitations, and that mechanical de- 
positions only appear in those qf a later 
period, that is, in the transition class, and 
thence they continue increasing, through 
all the succeeding classes of rocks. This 
evidence of the vast diminution of the 
volume of water which stood so high over 
the whole earth, is assumed to be perfectly 
satisfactory, although we can form no cor- 
rect idea of what has become of it. 
By the earliest separations from the 
chaotic mass, which are discoverable in 
the crust of the globe, was formed a class of 
