Theory of the Earth, Volume 1 (of 4)
by
James Hutton

Part 2 out of 6



For this purpose, we may consider two different species of strata,
such as are perfectly simple in their nature, of the most distinct
substances, and whose origin is perfectly understood, consequently,
whose subsequent changes may be reasoned upon with certainty and
clearness. These are the siliceous and calcareous strata; and these
are the two prevailing substances of the globe, all the rest being, in
comparison of these, as nothing; for unless it be the bituminous or coal
strata, there is hardly any other which does not necessarily contain
more or less of one or other of these two substances. If, therefore,
it can be shown, that both of those two general strata have been
consolidated by the simple fusion of their substance, no _desideratum_
or doubt will remain, with regard to the nature of that operation which
has been transacted at great depths of the earth, places to which all
access is denied to mortal eyes.

We are now to prove, _first_, That those strata have been consolidated
by simple fusion; and, _2dly_, That this operation is universal, in
relation to the strata of the earth, as having produced the various
degrees of solidity or hardness in these bodies.

I shall first remark, that a fortuitous collection of hard bodies, such
as gravel and sand, can only touch in points, and cannot, while in that
hard state, be made to correspond so precisely to each others shape as
to consolidate the mass. But if these hard bodies should be softened in
their substance, or brought into a certain degree of fusion, they
might be adapted mutually to each other, and thus consolidate the open
structure of the mass. Therefore, to prove the present point, we have
but to exhibit specimens of siliceous and calcareous strata which have
been evidently consolidated in this manner.

Of the first kind, great varieties occur in this country. It is,
therefore, needless to describe these particularly. They are the
consolidated strata of gravel and sand, often containing abundance of
feld-spar, and thus graduating into granite; a body, in this respect,
perfectly similar to the more regular strata which we now examine.

The second kind, again, are not so common in this country, unless
we consider the shells and coralline bodies in our lime-stones, as
exhibiting the same example, which indeed they do. But I have a specimen
of marble from Spain, which may be described, and which will afford the
most satisfactory evidence of the fact in question.

This Spanish marble may be considered as a species of pudding-stone,
being formed of calcareous gravel; a species of marble which, from Mr
Bowles' Natural History, appears to be very common in Spain. The gravel
of which this marble is composed, consists of fragments of other marbles
of different kinds. Among these, are different species of _oolites_
marble, some shell marbles, and some composed of a chalky substance, or
of undistinguishable parts. But it appears, that all these different
marbles had been consolidated or made hard, then broken into fragments,
rolled and worn by attrition, and thus collected together, along with
some sand or small siliceous bodies, into one mass. Lastly, This
compound body is consolidated in such a manner as to give the most
distinct evidence, that this had been executed by the operation of heat
or simple fusion.

The proof I give is this, That besides the general conformation of those
hard bodies, so as to be perfectly adapted to each other's shape, there
is, in some places, a mutual indentation of the different pieces of
gravel into each other; an indentation which resembles perfectly that
junction of the different bones of the _cranium_, called sutures, and
which must have necessarily required a mixture of those bodies while in
a soft or fluid state.

This appearance of indentation is by no means singular, or limited to
one particular specimen. I have several specimens of different marbles,
in which fine examples of this species of mixture may be perceived. But
in this particular case of the Spanish pudding-stone, where the mutual
indentation is made between two pieces of hard stone, worn round by
attrition, the softening or fusion of these two bodies is not simply
rendered probable, but demonstrated.

Having thus proved, that those strata had been consolidated by simple
fusion, as proposed, we now proceed to show, that this mineral operation
had been not only general, as being found in all the regions of the
globe, but universal, in consolidating our earth in all the various
degrees, from loose and incoherent shells and sand, to the most solid
bodies of the siliceous and calcareous substances.

To exemplify this in the various collections and mixtures of sands,
gravels, shells, and corals, were endless and superfluous. I shall only
take, for an example, one simple homogeneous body, in order to exhibit
it in the various degrees of consolidation, from the state of simple
incoherent earth to that of the most solid marble. It must be evident
that this is chalk; naturally a soft calcareous earth, but which may be
also found consolidated in every different degree.

Through the middle of the Isle of Wight, there runs a ridge of hills of
indurated chalk. This ridge runs from the Isle of Wight directly west
into Dorsetshire, and goes by Corscastle towards Dorchester, perhaps
beyond that place. The sea has broke through this ridge at the west
end of the Isle of Wight, where columns of the indurated chalk remain,
called the Needles; the same appearance being found upon the opposite
shore in Dorsetshire.

In this field of chalk, we find every gradation of that soft earthy
substance to the most consolidated body of this indurated ridge, which
is not solid marble, but which has lost its chalky property, and has
acquired a kind of stony hardness.

We want only further to see this cretaceous substance in its most
indurated and consolidated state; and this we have in the north of
Ireland, not far from the Giants Causeway. I have examined cargoes of
this lime-stone brought to the west of Scotland, and find the most
perfect evidence of this body having been once a mass of chalk, which is
now a solid marble.

Thus, if it is by means of fusion that the strata of the earth have
been, in many places, consolidated, we must conclude, that all the
degrees of consolidation, which are indefinite, have been brought about
by the same means.

Now, that all the strata of the mineral regions, which are those only
now examined, have been consolidated in some degree, is a fact for which
no proof can be offered here, but must be submitted to experience and
inquiry; so far, however, as they shall be considered as consolidated in
any degree, which they certainly are in general, we have investigated
the means which had been employed in that mineral operation.

We have now considered the concretions of particular bodies, and the
general consolidation of strata; but it may be alleged, that there is
a great part of the solid mass of this earth not properly comprehended
among those bodies which have been thus proved to be consolidated by
means of fusion. The body here alluded to is granite; a mass which is
not generally stratified, and which, being a body perfectly solid,
and forming some part in the structure of this earth, deserves to be
considered.

The nature of granite, as a part of the structure of the earth, is too
intricate a subject to be here considered, where we only seek to prove
the fusion of a substance from the evident marks which are to be
observed in a body. We shall, therefore, only now consider one
particular species of granite; and if this shall appear to have been in
a fluid state of fusion, we may be allowed to extend this property to
all the kind.

The species now to be examined comes from the north country, about four
or five miles west from Portfoy, on the road to Huntly. I have not been
upon the spot, but am informed that this rock is immediately connected
or continuous with the common granite of the country. This indeed
appears in the specimens which I have got; for, in some of these, there
is to be perceived a gradation from the regular to the irregular sort.

This rock may indeed be considered, in some respects, as a porphyry; for
it has an evident ground, which is feld-spar, in its sparry state;
and it is, in one view, distinctly maculated with quartz, which is
transparent, but somewhat dark-coloured[11].

[Note 11: Plate II. fig. 1. 2. 3.]

Considered as a porphyry, this specimen is no less singular than as a
granite. For, instead of a siliceous ground, maculated with the rhombic
feld-spar, which is the common state of porphyry, the ground is
uniformly crystallised, or a homogeneous regular feld-spar, maculated
with the transparent siliceous substance. But as, besides the feld-spar
and quartz, which are the constituent parts of the stone, there is also
mica, in some places, it may, with propriety, be termed a granite.

The singularity of this specimen consists, not in the nature or
proportions of its constituent parts, but in the uniformity of the
sparry ground, and the regular shape of the quartz mixture. This
siliceous substance, viewed in one direction, or longitudinally, may
be considered as columnar, prismatical, or continued in lines running
nearly parallel. These columnar bodies of quartz are beautifully
impressed with a figure on the sides, where they are in contact with the
spar. This figure is that of furrows or channels, which are perfectly
parallel, and run across the longitudinal direction of the quartz. This
is represented in fig. 4. This striated figure is only seen when, by
fracture, the quartz is separated from the contiguous spar.

But what I would here more particularly represent is, the transverse
section of those longitudinal siliceous bodies These are seen in fig. 1.
2. and 3. They have not only separately the forms of certain typographic
characters, but collectively give the regular lineal appearance of types
set in writing.

It is evident from the inspection of this fossil, that the sparry and
siliceous substances had been mixed together in a fluid state; and that
the crystallization of the sparry substance, which is rhombic, had
determined the regular structure of the quartz, at least in some
directions.

Thus, the siliceous substance is to be considered as included in the
spar, and as figured, according to the laws of crystallization proper
to the sparry ground; but the spar is also to be found included in the
quartz. It is not, indeed, always perfectly included or inclosed on all
sides; but this is sometimes the case, or it appears so in the section.
Fig. 5. 6. 7. 8. 9. and 10. are those cases magnified, and represent the
different figured quartz inclosing the feld-spar. In one of them, the
feld-spar, which is contained within the quartz, contains also a small
triangle of quartz, which it incloses. Now, it is not possible to
conceive any other way in which those two substances, quartz and
feld-spar, could be thus concreted, except by congelation from a fluid
state, in which they had been mixed.

There is one thing more to be observed with regard to this curious
species of granite. It is the different order or arrangement of the
crystallization or internal structure of the feld-spar ground, in two
contiguous parts of the same mass. This is to be perceived in the
polished surface of the stone, by means of the reflection of light.

There is a certain direction in which, viewing the stone, when the light
falls with a proper obliquity, we see a luminous reflection from the
internal parts of the stone. This arises from the reflecting surfaces
of the sparry structure or minute cracks, all turned in one direction,
consequently, giving that luminous appearance only in one point of view.

Now, all the parts of the stone in which the figured quartz is directed
in the same manner, or regularly placed in relation to each other,
present that shining appearance to the eye at one time, or in the same
point of direction. But there are parts of the mass, which, though
immediately contiguous and properly continuous, have a different
disposition of the figured quartz; and these two distinguished masses,
in the same surface of the polished stone, give to the eye their shining
appearance in very different directions. Fig. 3. shows two of those
figured and shining masses, in the same plane or polished surface.

It must be evident, that, as the crystallization of the sparry structure
is the figuring cause of the quartz bodies, there must be observed a
certain correspondency between those two things, the alinement (if I may
be allowed the expression) of the quartz, and the shining of the sparry
ground. It must also appear, that at the time of congelation of the
fluid spar, those two contiguous portions had been differently disposed
in the crystallization of their substance. This is an observation which
I have had frequent opportunities of making, with respect to masses of
calcareous spar.

Upon the whole, therefore, whether we shall consider granite as a
stratum or as an irregular mass, whether as a collection of several
materials, or as the separation of substances which had been mixed,
there is sufficient evidence of this body having been consolidated by
means of fusion, and in no other manner.

We are thus led to suppose, that the power of heat and operation
of fusion must have been employed in consolidating strata of loose
materials, which had been collected together and amassed at the bottom
of the ocean. It will, therefore, be proper to consider, what are the
appearances in consolidated strata that naturally should follow, on the
one hand, from fluidity having been, in this manner, introduced by means
of heat, and, on the other, from the interstices being filled by means
of solution; that so we may compare appearances with the one and other
of those two suppositions, in order to know that with which they may be
only found consistent.

The consolidation of strata with every different kind of substance was
found to be inconsistent with the supposition, that aqueous solution
had been the means employed for this purpose. This appearance, on the
contrary, is perfectly consistent with the idea, that the fluidity of
these bodies had been the effect of heat; for, whether we suppose the
introduction of foreign matter into the porous mass of a stratum for its
consolidation, or whether we shall suppose the materials of the mass
acquiring a degree of softness, by means of which, together with an
immense compression, the porous body might be rendered solid; the power
of heat, as the cause of fluidity and vapour, is equally proper and
perfectly competent. Here, therefore, appearances are as decidedly in
favour of the last supposition, as they had been inconsistent with the
first.

But if strata have been consolidated by means of aqueous solution, these
masses should be found precisely in the same state as when they were
originally deposited from the water. The perpendicular section of those
masses might show the compression of the bodies included in them, or of
which they are composed; but the horizontal section could not contain
any separation of the parts of the stratum from one another.

If, again, strata have been consolidated by means of heat, acting in
such a manner as to soften their substance, then, in cooling, they must
have formed rents or separations of their substance, by the unequal
degrees of contraction which the contiguous strata may have suffered.
Here is a most decisive mark by which the present question must be
determined.

There is not in nature any appearance more distinct than this of the
perpendicular fissures and separations in strata. These are generally
known to workmen by the terms of veins or backs and cutters; and there
is no consolidated stratum that wants these appearances. Here is,
therefore, a clear decision of the question, Whether it has been by
means of heat, or by means of aqueous solution, that collections of
loose bodies at the bottom of the sea have been consolidated into the
hardest rocks and most perfect marbles[12].

[Note 12: This subject is extremely interesting, both to the theory of
the earth, and to the science cf the mining art; I will now illustrate
that theory, with an authority which I received after giving this
dissertation to the Royal Society. It is in the second volume of M. de
Saussure's _voyages dans les Alpes_. Here I find proper examples for
illustrating that subject of mineralogy; and I am happy to have this
opportunity of giving the reasoning of a man of science upon the
subject, and the opinion of a person who is in every respect so well
qualified to judge upon a point of this kind.

The first example is of a marble in the Alps, (_voyages dans les
Alpes._) tom. 2. page 271.

"La pate de ces breches est tantot blanche, tantot grise, et les
fragmens qui y font renfermes font, les uns blancs, les autres gris,
d'autres roux, et presque toujours d'une couleur differente de celle de
la pate qui les lit. Ils sont tous de nature calcaire; tels etaient au
moins tous ceux que j'ai pus observer; et ce qu'il-y-a de remarquable,
c'est qu'ils sont tous poses dans le sens des feuillets de la pierre; on
diroit en les voyant, qu'ils ont tous ete comprimes et ecrases dans
le meme sens. Cette meme pierre est melee de mica, sur-tout dans les
interstices des couches et entre les fragmens et la pate qui les reunit;
mais on ne voit point de mica dans les fragmens eux-memes. On trouve
aussi dans ces breches des infiltrations de quartz. Cette pierre est
coupee par des frequentes fissures perpendiculaires aux plans des
couches. On voit clairement que ces fentes out ete formees par l'inegal
affaissement des couches, et non par une retraite spontanee: car les
morceaux ou fragmens etrangers sont tous partages et coupes net par ces
fissures au lieu que dans les divisions naturelles des couches, ces
memes fragmens sont entiers et saillans au dehors de la surface. Les
noeuds de quartz et les divers crystaux, que renferment les roches
feuilletees, presentent le meme phenomene, et l'on peut en tirer la meme
consequence; ils font partages dans les fentes, et entiers dans les
separations des couches."

He finds those particular strata in the other side of the mountain _col
de la Seigne_, and gives us the following observations:

"Plus bas on passe entre deux bancs de ces memes breches, entre lesquels
sont interposees des couches d'ardoises noires et de gres feuilletes
micaces, dont la situation est la meme.

"On retrouve encore ces breches vers le has de la descente, au pied de
pyramides calcaires dont j'ai parle plus haut. Je trouvai en 1774 de
tres-jolis crystaux de roche qui s'etaient formes dans les fentes de
cette breche. Il y avoit meme un melange de quartz et de mica qui
s'etoit moule dans quelques-une de ces fentes. C'etoit donc une roche
semblable aux primitives, et pourtant d'une formation posterieure a
celle de la pierre calcaire. Et quel systeme pourroit nous persuader que
la nature ne puisse encore produire ce qu'elle a produit autrefois!"

M. de Saussure has here given us an example of a calcareous Braccia,
as he calls it, but which is rather a pudding stone, with veins or
contractions of the mass. He does not seem to understand these as
consequences of the consolidation of those strata; this, however, is
the only light in which these appearances may be explained, when those
bodies are thus divided without any other separation in the mass.

The second example is found in the vertical strata of those mountains
through which the Rhone has made its way in running from the great
valley of the _Vallais_ towards the lake of Geneva. (Chapitre xlviii.)

"C'est une espece de petrosilex gris, dur, sonore, un peu transparent,
qui se debite en feuillets minces parfaitement plans et reguliers. Ces
feuillets, ou plutot ces couches, courent a 35 degres du nord par est,
en montant du cote de l'ouest sous un angle de 80 degres. Ces couches
sont coupees par des fentes qui leur sont a-peu-pres perpendiculaires et
qui le sont aussi a l'horizon. Cette pierre s'emploie aux memes usage
que l'ardoise, mais elle est beaucoup plus forte et plus durable, parce
qu'elle est plus dure et moins accessible aux impressions de l'eau et de
l'air.

Sec. 1047. "Ces petrosilex feuilletes changent peu-a-peu de nature, en
admettant dans les interstices de leurs feuillets des parties de
feldspath. Ils out alors l'apparence d'une roche feuilletee, quartzeuse
et micacee, (_quartzum fornacum W._). Mais cette apparence est
trompeuse; car on n'y trouve pas un atome de quartz: toutes les parties
blanches qui donnent du feu contre l'acier, font du feldspath; et les
parties grise ecailleuses ne font point du mica, ce sont de lames minces
du petrosilex dont j'ai deja parle."

Here is evidently what I would call petuntze strata, or porcelane stone,
that is, strata formed by the deposits of such materials as might come
from the _detritus_ of granite, arranged at the bottom of the sea, and
consolidated by heat in the mineral regions. We have precisely such
stratified masses in the Pentland hills near Edinburgh. I have also a
specimen of the same kind, brought from the East Indies, in which there
is the print of an organized body. I believe it to be of some coralline
or zoophite.

Sec. 1048. "Cette roche melangee continue jusqu'a ce que le rocher
s'eloigne un peu du grand chemin. La, ce rocher se presente coupe a
pic dans une grande etendue, et divise par de grandes fentes obliques,
a-peu-pres paralleles entr'elles. Ces fentes partagent la montagne en
grandes tranches de 50 a 60 pieds d'epaisseur, que de loin semblent etre
des couches. Mais lorsqu'on s'en approche, on voit, par le tissu meme
de la pierre feuilletee, que ses vraies couches font avec l'horizon des
angles de 70 a 75 degre, et que ces grandes divisions sont de vraies
fentes par lesquelles un grand nombre de couches consecutives sont
coupees presque perpendiculairement a leurs plans. Les masses de rocher,
comprises entre ces grandes fentes, sont encore divisees par d'autres
fentes plus petites, dont la plupart sont paralleles aux grandes,
d'autres leur sont obliques; mais toutes sont a tres-peu-pres
perpendiculaires aux plans des couches dont la montagne est composee."

Here is a distinct view of that which may be found to take place in all
consolidated strata, whatever be the composition of the stratum; and
it is this appearance which is here maintained to be a physical
demonstration, that those strata had been consolidated by means of
heat softening their materials. In that case, those stratified
bodies, contracting in cooling, form veins and fissures traversing
perpendicularly their planes; and these veins are afterwards filled with
mineral substances. These are what I have here distinguished as the
_particular_ veins of mineral masses; things perfectly different from
proper mineral or metallic veins, which are more general, as belonging
to immense masses of those strata; and which had been formed, not from
the contraction, but from the disrupture of those masses, and by the
forcible injection of fluid mineral substances from below. Now these two
species of veins, the particular and the general, although occasionally
connected, must be in science carefully distinguished; in the one, we
see the means which had been employed for the consolidation of the
strata; in the other, we see that power by which the strata have been
raised from the bottom of the sea and placed in the atmosphere.]

Error never can be consistent, nor can truth fail of having support from
the accurate examination of every circumstance. It is not enough to
have found appearances decisive of the question, with regard to the
two suppositions which have been now considered, we may farther seek
confirmation of that supposition which has been found alone consistent
with appearances.

If it be by means of heat and fusion that strata have been consolidated,
then, in proportion to the degree of consolidation they have undergone
from their original state, they should, _caeteris paribus_, abound more
with separations in their mass. But this conclusion is found consistent
with appearances. A stratum of porous sand-stone does not abound so much
with veins and cutters as a similar stratum of marble, or even a
similar stratum of sand-stone that is more consolidated. In proportion,
therefore, as strata have been consolidated, they are in general
intersected with veins and cutters; and in proportion as strata are
deep in their perpendicular section, the veins are wide, and placed at
greater distances. In like manner, when strata are thin, the veins are
many, but proportionally narrow.

It is thus, upon chemical principles, to be demonstrated, That all the
solid strata of the globe have been condensed by means of heat, and
hardened from a state of fusion. But this proposition is equally to
be maintained from principles which are mechanical. The strata of the
globe, besides being formed of earths, are composed of sand, of gravel,
and fragments of hard bodies, all which may be considered as, in their
nature, simple; but these strata are also found composed of bodies which
are not simple, but are fragments of former strata, which had been
consolidated, and afterwards were broken and worn by attrition, so as
to be made gravel. Strata composed in this manner have been again
consolidated; and now the question is, By what means?

If strata composed of such various bodies had been consolidated, by any
manner of concretion, from the fluidity of a dissolution, the hard and
solid bodies must be found in their entire state, while the interstices
between those constituent parts of the stratum are filled up. No partial
fracture can be conceived as introduced into the middle of a solid mass
of hard matter, without having been communicated from the surrounding
parts. But such partial separations are found in the middle of those
hard and solid masses; therefore, this compound body must have been
consolidated by other means than that of concretion from a state of a
solution.

The Spanish marble already described, as well as many consolidated
strata of siliceous gravel, of which I have specimens, afford the
clearest evidence of this fact. These hard bodies are perfectly united
together, in forming the most solid mass; the contiguous parts of some
of the rounded fragments are interlaced together, as has already been
observed; and there are partial shrinkings of the mass forming veins,
traversing several fragments, but perfectly filled with the sparry
substance of the mass, and sometimes with parts of the stone distinctly
floating in the transparent body of spar. Now, there is not, besides
heat or fusion, any known power in nature by which these effects might
be produced. But such effects are general to all consolidated masses,
although not always so well illustrated in a cabinet specimen.

Thus we have discovered a truth that is confirmed by every appearance,
so far as the nature of the subject now examined admits. We now return
to the general operation, of forming continents of those materials which
had been deposited at the bottom of the sea.


SECTION III.

Investigation of the Natural Operations employed in the Production of
Land above the Surface of the Sea.

We seek to know that operation by means of which masses of loose
materials, collected at the bottom of the sea, were raised above its
surface, and transformed into solid land.

We have found, that there is not in this globe (as a planet revolving
in the solar system) any power or motion adapted to the purpose now in
view; nor, were there such a power, could a mass of simply collected
materials have continued any considerable time to resist the waves and
currents natural to the sea, but must have been quickly carried away,
and again deposited at the bottom of the ocean. But we have found, that
there had been operations, natural to the bowels of this earth; by which
those loose and unconnected materials have been cemented together, and
consolidated into masses of great strength and hardness; those bodies
are thus enabled to resist the force of waves and currents, and to
preserve themselves, for a sufficient time, in their proper shape and
place, as land above the general surface of the ocean.

We now desire to know, how far those internal operations of the globe,
by which solidity and stability are procured to the beds of loose
materials, may have been also employed in raising up a continent of
land, to remain above the surface of the sea.

There is nothing so proper for the erection of land above the level of
the ocean, as an expansive power of sufficient force, applied directly
under materials in the bottom of the sea, under a mass that is proper
for the formation of land when thus erected. The question is not, how
such a power may be procured; such a power has probably been employed.
If, therefore, such a power should be consistent with that which we
found had actually been employed in preparing the erected mass; or,
if such a power is to be reasonably concluded as accompanying those
operations which we have found natural to the globe, and situated in the
very place where this expansive power appears to be required, we should
thus be led to perceive, in the natural operations of the globe, a power
as efficacious for the elevation of what had been at the bottom of the
sea into the place of land, as it is perfect for the preparation of
those materials to serve the purpose of their elevation.

In opposition to this conclusion, it will not be allowed to allege; that
we are ignorant how such a power might be exerted under the bottom of
the ocean; for, the present question is not, what had been the cause of
heat, which has appeared to have been produced in that place, but if
this power of heat, which has certainly been exerted at the bottom of
the ocean for consolidating strata, had been employed also for another
purpose, that is, for raising those strata into the place of land.

We may, perhaps, account for the elevation of land, by the same cause
with that of the consolidation of strata, already investigated, without
explaining the means employed by nature in procuring the power of heat,
or showing from what general source of action this particular power had
been derived; but, by finding in subterranean heat a cause for any other
change, besides the consolidation of porous or incoherent bodies, we
shall generalise a fact, or extend our knowledge in the explanation of
natural appearances.

The power of heat for the expansion of bodies, is, so far as we know,
unlimited; but, by the expansion of bodies placed under the strata at
the bottom of the sea, the elevation of those strata may be effected;
and the question now to be resolved regards the actual exertion of
this power of expansion. How far it is to be concluded as having been
employed in the production of this earth above the level of the sea.

Before attempting to resolve that question, it may be proper to observe,
there has been exerted an extreme degree of heat below the strata formed
at the bottom of the sea; and this is precisely the action of a power
required for the elevation of those heated bodies into a higher place.
Therefore, if there is no other way in which we may conceive this event
to have been brought about, consistent with the present state of things,
or what actually appears, we shall have a right to conclude, that such
had been the order of procedure in natural things, and that the
strata formed at the bottom of the sea had been elevated, as well as
consolidated, by means of subterraneous heat.

The consolidation of strata by means of fusion or the power of heat, has
been concluded from the examination of nature, and from finding, that
the present state of things is inconsistent with any other supposition.
Now, again, we are considering the only power that may be conceived as
capable of elevating strata from the bottom of the sea, and placing such
a mass above the surface of the water. It is a truth unquestionable,
that what had been originally at the bottom of the sea, is at present
the highest of our land. In explaining this appearance, therefore, no
other alternative is left, but either to suppose strata elevated by the
power of heat above the level of the present sea, or the surface of the
ocean reduced many miles below the height at which it had subsisted
during the collection and induration of the land which we inhabit.

Now, if, on the one hand, we are to suppose no general power of
subterraneous fire or heat, we leave to our theory no means for the
retreat of the sea, or the lowering of its surface; if, on the other
hand, we are to allow the general power of subterraneous heat, we cannot
have much difficulty in supposing, either the surface of the sea to have
subsided, or the bottom of the ocean, in certain parts, to have been
raised by a subterranean power above the level of its surface, according
as appearances shall be found to require the one or other of those
conclusions. Here, therefore, we are again remitted to the history of
nature, in order to find matter of fact by which this question may be
properly decided.

If the present land had been discovered by the subsiding of the waters,
there has not been a former land, from whence materials had been
procured for the construction of the present, when at the bottom of the
sea; for, there is no vestige remaining of that land, the whole land of
the present earth having been formed evidently at the bottom of the sea.
Neither could the natural productions of the sea have been accumulated,
in the shape in which we now find them, on the surface of this earth;
for, How should the Alps and Andes have been formed within the sea
from the natural productions of the water? Consequently, this is a
supposition inconsistent with every natural appearance.

The supposition, therefore, of the subsidence of the former ocean,
for the purpose of discovering the present land, is beset with more
difficulty than the simple erection of the bottom of the former ocean;
for, _first_, There is a place to provide for the retirement of the
waters of the ocean; and, _2dly_, There is required a work of equal
magnitude; this is, the swallowing up of that former continent, which
had procured the materials of the present land.

On the one hand, the subsiding of the surface of the ocean would but
make the former land appear the higher; and, on the other, the sinking
the body of the former land into the solid globe, so as to swallow up
the greater part of the ocean after it, if not a natural impossibility,
would be at least a superfluous exertion of the power of nature. Such an
operation as this would discover as little wisdom in the end elected, as
in the means appropriated to that end; for, if the land be not wasted
and worn away in the natural operations of the globe, Why make such a
convulsion in the world in order to renew the land? If, again, the land
naturally decays, Why employ so extraordinary a power, in order to hide
a former continent of land, and puzzle man?

Let us now consider how far the other proposition, of strata being
elevated by the power of heat above the level of the sea, may be
confirmed from the examination of natural appearances.

The strata formed at the bottom of the ocean are necessarily horizontal
in their position, or nearly so, and continuous in their horizontal
direction or extent. They may change, and gradually assume the nature of
each other, so far as concerns the materials of which they are formed;
but there cannot be any sudden change, fracture, or displacement,
naturally in the body of a stratum. But, if these strata are cemented by
the heat of fusion, and erected with an expansive power acting below,
we may expect to find every species of fracture, dislocation, and
contortion, in those bodies, and every degree of departure from a
horizontal towards a vertical position.

The strata of the globe are actually found in every possible position:
For, from horizontal, they are frequently found vertical; from
continuous, they are broken and separated in every possible direction;
and, from a plane, they are bent and doubled. It is impossible that they
could have originally been formed, by the known laws of nature, in their
present state and position; and the power that has been necessarily
required for their change, has not been inferior to that which might
have been required for their elevation from the place in which they had
been formed.

In this cafe, natural appearances are not anomalous. They are, indeed,
infinitely various, as they ought to be, according to the rule; but all
those varieties in appearances conspire to prove one general truth, viz.
That all which we see had been originally composed according to certain
principles, established in the constitution of the terraqueous globe;
and that those regular compositions had been afterwards greatly changed
by the operations of another power, which had introduced apparent
confusion among things first formed in order and by rule.

It is concerning the operation of this second power that we are now
inquiring; and here the apparent irregularity and disorder of the
mineral regions are as instructive, with regard to what had been
transacted in a former period of time, as the order and regularity of
those same regions are conclusive, in relation to the place in which a
former state of things had produced that which, in its changed state, we
now perceive.

We are now to conclude, that the land on which we dwell had been
elevated from a lower situation by the same agent which had been
employed in consolidating the strata, in giving them stability, and
preparing them for the purpose of the living world. This agent is matter
actuated by extreme heat, and expanded with amazing force.

If this has been the case, it will be reasonable to expect, that some of
the expanded matter might be found condensed in the bodies which have
been heated by that igneous vapour; and that matter, foreign to the
strata, may have been thus introduced into the fractures and separations
of those indurated masses.

We have but to open our eyes to be convinced of this truth. Look into
the sources of our mineral treasures; ask the miner, from whence has
come the metal into his vein? Not from the earth or air above,--not from
the strata which the vein traverses; these do not contain one atom of
the minerals now considered. There is but one place from whence these
minerals may have come; this is the bowels of the earth, the place of
power and expansion, the place from whence must have proceeded that
intense heat by which loose materials have been consolidated into rocks,
as well as that enormous force by which the regular strata have been
broken and displaced.

Our attention is here peculiarly called upon, where we have the
opportunity of examining those mineral bodies, which have immediately
proceeded from the unknown region, that place of power and energy which
we want to explore; for, if such is the system of the earth, that
materials are first deposited at the bottom of the ocean, there to be
prepared in a certain manner, in order to acquire solidity, and then to
be elevated into the proper place of land, these mineral veins, which
contain matter absolutely foreign to the surface of the earth, afford
the most authentic information with regard to the operations which we
want to understand. It is these veins which we are to consider as,
in some measure, the continuation of that mineral region, which lies
necessarily out of all possible reach of our examination. It is,
therefore, peculiarly interesting to know the state in which things
are to be found in this place, which may be considered as intermediate
between the solid land, upon the one hand, and the unknown regions of
the earth, upon the other.

We are now to examine those mineral veins; and these may be considered,
first, in relation to their form, independent of their substance or
particular contents; and, secondly, in relation to the contained bodies,
independent of their form.

In examining consolidated strata, we remarked veins and cutters as a
proof of the means by which those bodies had been consolidated. In that
case, the formation of these veins is a regulated process, determined
by the degree of fusion, and the circumstances of condensation or
refrigeration. In respect of these, the mineral veins now to be examined
are anomalous. They are; but we know not why or how. We see the effect;
but, in that effect, we do not see the cause. We can say, negatively,
that the cause of mineral veins is not that by which the veins and
fissures of consolidated strata have been formed; consequently, that
it is not the measured contraction and regulated condensation of the
consolidated land which has formed those general mineral veins; however,
veins, similar in many respects, have been formed by the cooperation of
this cause.

Having thus taken a view of the evident distinction between the veins or
contractions that are particular to the consolidated body in which they
are found, and those more general veins which are not limited to that
cause, we may now consider what is general in the subject, or what is
universal in these effects of which we wish to investigate the cause.

The event of highest generalization or universality, in the form of
those mineral veins, is fracture and dislocation. It is not, like that
of the veins of strata, simple separation and measured contraction; it
is violent fracture and unlimited dislocation. In the one case, the
forming cause is in the body which is separated; for, after the body had
been actuated by heat, it is by the reaction of the proper matter of the
body, that the chasm which constitutes the vein is formed. In the other
case, again, the cause is extrinsic in relation to the body in which the
chasm is formed. There has been the most violent fracture and divulsion;
but the cause is still to seek; and it appears not in the vein; for it
is not every fracture and dislocation of the solid body of our earth, in
which minerals, or the proper substances of mineral veins, are found.

We are now examining matter of fact, real effects, from whence we would
investigate the nature of certain events which do not now appear. Of
these, two kinds occur; one which has relation to the hardness and
solidity, or the natural constitution of the body; the other, to its
shape or local situation. The first has been already considered; the
last is now the subject of inquiry.

But, in examining those natural appearances, we find two different kinds
of veins; the one necessarily connected with the consolidating cause;
the other with that cause of which we now particularly inquire. For,
in those great mineral veins, violent fracture and dislocation is the
principle; but there is no other principle upon which strata, or masses
formed at the bottom of the sea, can be placed at a height above its
surface. Hence, in those two different operations, of forming mineral
veins, and erecting strata from a lower to a higher place, the principle
is the same; for, neither can be done without violent fracture and
dislocation.

We now only want to know, how far it is by the same power, as well as
upon the same principle, that these two operations have been made.
An expansive force, acting from below, is the power most proper for
erecting masses; but whether it is a power of the same nature with that
which has been employed in forming mineral veins, will best appear in
knowing the nature of their contents. These, therefore, may be now
considered.

Every species of fracture, and every degree of dislocation and
contortion, may be perceived in the form of mineral veins; and there is
no other general principle to be observed in examining their form. But,
in examining their contents, some other principle may appear, so far as,
to the dislocating power or force, there may be superadded matter, by
which something in relation to the nature of the power may be known.
If, for example, a tree or a rock shall be found simply split asunder,
although there be no doubt with regard to some power having been applied
in order to produce the effect, yet we are left merely to conjecture at
the power. But when wedges of wood or iron, or frozen water, should be
found lodged in the cleft, we might be enabled, from this appearance, to
form a certain judgment with regard to the nature of the power which
had been applied. This is the case with mineral veins. We find them
containing matter, which indicates a cause; and every information in
this case is interesting to the theory.

The substances contained in mineral veins are precisely the same with
those which, in the former section, we have considered as being made
instrumental in the consolidation of strata; and they are found mixed
and concreted in every manner possible.

But, besides this evidence for the exertion of extreme heat, in that
process by which those veins were filled, there is another important
observation to be gathered from the inspection of this subject. There
appears to have been a great mechanical power employed in the filling of
these veins, as well as that necessarily required in making the first
fracture and divulsion.

This appears from the order of the contents, or filling of these veins,
which is a thing often observed to be various and successive. But what
it is chiefly now in view to illustrate, is that immense force which is
manifested in the fracture and dispersion of the solid contents which
had formerly filled those veins. Here we find fragments of rock and spar
floating in the body of a vein filled with metallic substances; there,
again, we see the various fragments of metallic masses floating in the
sparry and siliceous contents.

One thing is demonstrable from the inspection of the veins and their
contents; this is, the successive irruptions of those fluid substances
breaking the solid bodies which they meet, and floating those fragments
of the broken bodies in the vein. It is very common to see three
successive series of those operations; and all this may be perceived in
a small fragment of stone, which a man of science may examine in his
closet, often better than descending to the mine, where all the examples
are found on an enlarged scale.

Let us now consider what power would be required to force up, from the
most unfathomable depth of the ocean, to the Andes or the Alps, a column
of fluid metal and of stone. This power cannot be much less than that
required to elevate the highest land upon the globe. Whether, therefore,
we shall consider the general veins as having been filled by mineral
steams, or by fluid minerals, an elevating power of immense force is
still required, in order to form as well as fill those veins. But such a
power acting under the consolidated masses at the bottom of the sea, is
the only natural means for making those masses land.

If such have been the operations that are necessary for the production
of this land; and if these operations are natural to the globe of this
earth, as being the effect of wisdom in its contrivance, we shall
have reason to look for the actual manifestation of this truth in the
phaenomena of nature, or those appearances which more immediately
discover the actual cause in the perceived effect.

To see the evidence of marble, a body that is solid, having been formed
of loose materials collected at the bottom of the sea, is not always
easy, although it may be made abundantly plain; and to be convinced that
this calcareous stone, which calcines so easily in our fires, should
have been brought into fusion by subterraneous heat, without suffering
calcination, must require a chain of reasoning which every one is not
able to attain[13]. But when fire bursts forth from the bottom of the
sea, and when the land is heaved up and down, so as to demolish cities
in an instant, and split asunder rocks and solid mountains, there
is nobody but must see in this a power, which may be sufficient to
accomplish every view of nature in erecting land, as it is situated in
the place most advantageous for that purpose.

[Note 13: Mr le Chevalier de Dolomieu, in considering the different
effects of heat, has made the following observation; Journal de
Physique, Mai 1792.

"Je dis _le feu tel que nous l'employons_ pour distinguer le feu naturel
des volcans, du feu de nos fourneaux et de celui de nos chalumeaux. Nous
sommes obliges de donner une grande activite a son action pour suppleer
et au volume qui ne seroit pas a notre disposition et au tems que nous
sommes forces de menager, et cette maniere d'appliquer une chaleur
tres-active, communique le mouvement et le desordre jusques dans les
molecules constituantes. Agregation et composition, tout est trouble.
Dans les volcans la grand masse du feu supplee a son intensite, le
tems remplace son activite, de maniere qu'il tourmente moins les corps
fournis a son action; il menage leur composition en relachant leur
agregation, et les pierres qui eut ete rendues fluides par l'embrasement
volcanique peuvent reprendre leur etat primitif; la plupart des
substances qu'un feu plus actif auroit expulsees y restent encore. Voila
pourquoi les laves ressemblent tellement aux pierres naturelles des
especes analogues, qu'elles ne peuvent en etre distinguees; voila
egalement pourquoi les verres volcaniques eux-meme renferment encore des
substances elastiques qui les font boursoufler lorsque nous les fondons
de nouveau, et pourquoi ces verres blanchissent aussi, pour lors, par
la dissipation, d'une substance grasse qui a resiste a la chaleur des
volcans, et que volatilise la chaleur par laquelle nous obtenons leur
second fusion."

No doubt, the long application of heat may produce changes in bodies
very different from those which are occasioned by the sudden application
of a more intense heat; but still there must be sufficient intensity in
that power, so as to cause fluidity, without which no chemical change
can be produced in bodies. The essential difference, however, between
the natural heat of the mineral regions, and that which we excite upon
the surface of the earth, consists in this; that nature applies heat
under circumstances which we are not able to imitate, that is, under
such compression as shall prevent the decomposition of the constituent
substances, by the separation of the more volatile from the more fixed
parts. This is a circumstance which, so far as I know, no chemist
or naturalist has hitherto considered; and it is that by which the
operations of the mineral regions must certainly be explained. Without
attending to this great principle in the mineralizing operations
of subterraneous fire, it is impossible to conceive the fusion and
concretion of those various bodies, which we examine when brought up to
the surface of the earth.]

The only question, therefore, which it concerns us to decide at present,
is, Whether those operations of extreme heat, and violent mechanic
force, be only in the system as a matter of accident; or if, on the
contrary, they are operations natural to the globe, and necessary in the
production of such land as this which we inhabit? The answer to this is
plain: These operations of the globe remain at present with undiminished
activity, or in the fullness of their power.

A stream of melted lava flows from the sides of Mount Aetna. Here is a
column of weighty matter raised from a great depth below, to an immense
height above, the level of the sea, and rocks of an enormous size
are projected from its orifice some miles into the air. Every one
acknowledges that here is the liquefying power and expansive force of
subterranean fire, or violent heat. But, that Sicily itself had been
raised from the bottom of the ocean, and that the marble called Sicilian
Jasper, had its solidity upon the same principle with the lava, would
stumble many a naturalist to acknowledge. Nevertheless, I have in my
possession a table of this marble, from which it is demonstrable, that
this calcareous stone had flowed, and been in such a state of fusion and
fluidity as lava.

Here is a comparison formed of two mineral substances, to which it is of
the highest importance to attend. The solidity and present state of the
one of these is commonly thought to be the operation of fire; of the
other, again, it is thought to be that of water. This, however, is not
the case. The immediate state and condition of both these bodies is now
to be considered as equally the effect of fire or heat. The reason of
our forming such a different judgment with regard to these two subjects
is this; we see, in the one case, the more immediate connection of the
cause and the effect, while, in the other, we have only the effects from
whence we are in science to investigate the cause.

But, if it were necessary always to see this immediate connection, in
order to acknowledge the operation of a power which, at present, is
extinguished in the effect, we should lose the benefit of science, or
general principles, from whence particulars may be deduced, and we
should be able to reason no better than the brute. Man is made for
science; he reasons from effects to causes, and from causes to effects;
but he does not always reason without error. In reasoning, therefore,
from appearances which are particular, care must be taken how we
generalise; we should be cautious not to attribute to nature, laws which
may perhaps be only of our own invention.

The immediate question now before us is not, If the subterraneous fire,
or elevating power, which we perceive sometimes as operating with such
energy, be the consolidating cause of strata formed at the bottom of the
sea; nor, if that power be the means of making land appear above the
general surface of the water? for, though this be the end we want to
arrive at ultimately, the question at present in agitation respects the
laws of nature, or the generality of particular appearances.

Has the globe within it such an active power as fits it for the
renovation of that part of its constitution which may be subject to
decay? Are those powerful operations of fire, or subterraneous heat,
which so often have filled us with terror and astonishment, to be
considered as having always been? Are they to be concluded as proper to
every part upon the globe, and as continual in the system of this earth?
If these points in question shall be decided in the affirmative, we can
be at no loss in ascertaining the power which has consolidated strata,
nor in explaining the present situation of those bodies, which had their
origin at the bottom of the sea. This, therefore, should be the object
of our pursuit; and in order to have demonstration in a case of physical
inquiry, we must again have recourse to the book of nature.

The general tendency of heat is to produce fluidity and softness; as
that of cold is, on the contrary, to harden soft and fluid bodies. But
this softening power of heat is not uniform in its nature; it is made to
act with very different effect, according to the nature of the substance
to which it is applied. We are but limited in the art of increasing the
heat or the cold of bodies; we find, however, extreme difference in
their substances with respect to fusibility.

A fusible substance, or mineral composition in a fluid state, is emitted
from those places of the earth at which subterraneous fire and expansive
force are manifested in those eruptive operations. In examining these
emitted bodies, men of science find a character for such productions, in
generalising the substance, and understanding the natural constitution
of those bodies. It is in this manner that such a person, finding a
piece of lava in any place of the earth, says with certainty, Here is a
stone which had congealed from a melted state.

Having thus found a distinguishing character for those fused substances
called, in general, Lavas, and having the most visible marks for that
which had been actually a volcano, naturalists, in examining different
countries, have discovered the most undoubted proofs of many ancient
volcanos, which had not been before suspected. Thus, volcanos will
appear to be not a matter of accident, or as only happening in a
particular place, they are general to the globe, so far as there is
no place upon the earth that may not have an eruption of this kind;
although it is by no means necessary for every place to have had those
eruptions.

Volcanos are natural to the globe, as general operations; but we are
not to consider nature as having a burning mountain for an end in her
intention, or as a principal purpose in the general system of this
world. The end of nature in placing an internal fire or power of heat,
and a force of irresistible expansion, in the body of this earth, is to
consolidate the sediment collected at the bottom of the sea, and to form
thereof a mass of permanent land above the level of the ocean, for the
purpose of maintaining plants and animals. The power appointed for this
purpose is, as on all other occasions, where the operation is important,
and where there is any danger of a shortcoming, wisely provided
in abundance; and there are contrived means for disposing of the
redundancy. These, in the present case, are our volcanos.

A volcano is not made on purpose to frighten superstitious people
into fits of piety and devotion, nor to overwhelm devoted cities with
destruction; a volcano should be considered as a spiracle to the
subterranean furnace, in order to prevent the unnecessary elevation of
land, and fatal effects of earthquakes; and we may rest assured, that
they, in general, wisely answer the end of their intention, without
being in themselves an end, for which nature had exerted such amazing
power and excellent contrivance.

Let us take a view of the most elevated places of the earth; if the
present theory is just, it is there that we should find volcanos. But is
not this the case? There are volcanos in the Andes; and round the Alps
we find many volcanos, which are in France upon the one side, and in
Germany upon the other, as well as upon the Italian side, where Vesuvius
still continues to exhibit violent eruptions.

It is not meant to allege, that it is only upon the summit of a
continent volcanos should appear. Subterraneous fire has sometimes made
its appearance in bursting from the bottom of the sea. But, even in
this last case, land was raised from the bottom of the sea, before the
eruption made its exit into the atmosphere. It must also be evident,
that, in this case of the new island near Santorini, had the expansive
power been retained, instead of being discharged, much more land might
have been raised above the level of the ocean.

Now, the eruption of that elastic force through the bottom of the sea,
may be considered as a waste of power in the operations of the globe,
where the elevation of indurated strata is an object in the exertion of
that power; whereas, in the centre of a continent sufficiently elevated
above the level of the sea, the eruption of that fiery vapour calculated
to elevate the land, while it may occasionally destroy the habitations
of a few, provides for the security and quiet possession of the many.

In order to see the wisdom of this contrivance, let us consider the
two extreme places at which this eruption of ignited matter may be
performed. These are, on the one hand, within a continent of land, and,
on the other, at the bottom of the ocean. In the one case, the free
eruption of the expanding power should be permitted; because the purpose
for which it had been calculated to exist has been accomplished. In
the other, again, the free eruption of that powerful matter should be
repressed; because there is reserved for that power much of another
operation in that place. But, according to the wise constitution of
things, this must necessarily happen. The eruption of the fiery
vapour from volcanos on the continent or land, is interrupted only
occasionally, by the melted bodies flowing in the subterraneous
chimney; whereas, at the bottom of the ocean, the contact of the water
necessarily tends to close the orifice, by accumulating condensed matter
upon the weakest place.

If this be a just theory of the natural operations of the globe, we
shall have reason to expect, that great quantities of this melted
matter, or fusible substance, may be found in form of lava, among the
strata of the earth, where there are no visible marks of any volcano, or
burning mountain, having existed. Here, therefore, is an important point
to be determined; for, if it shall appear that much of this melted
matter, analogous to lava, has been forced to flow among the strata
which had been formed at the bottom of the sea, and now are found
forming dry land above its surface, it will be allowed, that we have
discovered the secret operations of nature concocting future land, as
well as those by which the present habitable earth had been produced
from the bottom of the abyss. Here, therefore, we shall at present rest
the argument, with endeavouring to show that such is actually the case.

It appears from Cronstedt's Mineralogy, that the rock-stone, called trap
by the Swedes, the amygdaloides and the schwarts-stein of the Germans,
are the same with the whin-stone of this country. This is also fully
confirmed by specimens from Sweden, sent me by my friend Dr Gahn.
Whatever, therefore, shall be ascertained with regard to our whin-stone,
may be so far generalized or extended to the countries of Norway,
Sweden, and Germany.

The whin-stone of Scotland is also the same with the toad-stone of
Derbyshire, which is of the amygdaloides species; it is also the same
with the flagstone of the south of Staffordshire, which is a simple
whin-stone, or perfect trap. England, therefore, must be included in
this great space of land, the mineral operations of which we explore;
and also Ireland, of which the Giant's Causeway, and many others, are
sufficient proof.

In the south of Scotland, there is a ridge of hills, which extends
from the west side of the island in Galloway to the east side in
Berwickshire, composed of granite, of schistus, and of siliceous strata.
The Grampians on the north, again, form another range of mountains of
the same kind; and between these two great fields of broken, tumbled,
and distorted strata, there lies a field of lesser hardness and
consolidation, in general; but a field in which there is a great
manifestation of subterraneous fire, and of exerted force.

The strata in this space consist, in general, of sand-stone, coal,
lime-stone or marble, iron-stone, and marl or argillaceous strata, with
strata of analogous bodies, and the various compositions of these. But
what is to the present purpose is this, that, through all this space,
there are interspersed immense quantities of whinstone; a body which is
to be distinguished as very different from lava; and now the disposition
of this whin-stone is to be considered.

Sometimes it is found in an irregular mass or mountain, as Mr Cronstedt
has properly observed; but he has also said, that this is not the case
in general. His words are: "It is oftener found in form of veins in
mountains of another kind, running commonly in a serpentine manner,
contrary or across to the direction of the rock itself."

The origin of this form, in which the trap or whin-stone appears, is
most evident to inspection, when we consider that this solid body had
been in a fluid state, and introduced, in that state, among strata,
which preserved their proper form. The strata appear to have been
broken, and the two correspondent parts of those strata are separated to
admit the flowing mass of whin-stone.

A fine example of this kind may be seen upon the south side of the
Earn, on the road to Crief. It is twenty-four yards wide, stands
perpendicular, and appears many feet above the surface of the ground. It
runs from that eastward, and would seem to be the same with that which
crosses the river Tay, in forming Campsy-lin above Stanley, as a lesser
one of the same kind does below it. I have seen it at Lednoc upon the
Ammon, where it forms a cascade in that river, about five or six
miles west of Campsy-lin. It appears to run from the Tay east through
Strathmore, so that it may be considered as having been traced for
twenty or thirty miles, and westwards to Drummond castle, perhaps much
farther.

Two small veins of the same kind, only two or three feet wide, may be
seen in the bed of the Water of Leith, traversing the horizontal strata,
the one is above St Bernard's well, the other immediately below it. But,
more particularly, in the shire of Ayr, to the north of Irvine, there
are to be seen upon the coast, between that and Scarmorly, in the space
of about twenty miles, more than twenty or thirty such dykes (as they
are called) of whin-stone. Some of them are of a great thickness; and,
in some places, there is perceived a short one, running at right angles,
and communicating with other two that run parallel.

There is in this country, and in Derbyshire[14], another regular
appearance of this stone, which Cronstedt has not mentioned. In this
case, the strata are not broken in order to have the whin-stone
introduced, they are separated, and the whin-stone is interjected in
form of strata, having various degrees of regularity, and being of
different thickness. On the south side of Edinburgh, I have seen, in
little more than the space of a mile from east to west, nine or ten
masses of whin-stone interjected among the strata. These masses of
whin-stone are from three or four to an hundred feet thick, running
parallel in planes inclined to the horizon, and forming with it an angle
of about twenty or thirty degrees, as may be seen at all times in the
hill of Salisbury Craggs.

[Note 14: See Mr Whitehurst's Theory of the Earth.]

Having thus described these masses, which have flowed by means of
heat among the strata of the globe, strata which had been formed by
subsidence at the bottom of the sea, it will now be proper to examine
the difference that subsists between these subterraneous lavas, as they
may be termed, and the analogous bodies which are proper lavas, in
having issued out of a volcano.[15]

[Note 15: The Chevalier de Dolomieu, in his accurate examination of
Aetna and the Lipari islands, has very well observed the distinction of
these two different species of lavas; but without seeming to know the
principle upon which this essential difference depends. No bias of
system, therefore, can here be supposed as perverting the Chevalier's
view, in taking those observations; and these are interesting to the
present theory, as corresponding perfectly with the facts from whence it
has been formed. It will be proper to give the account of these in his
own words.

La zeolite est tres-commune dans certains laves de l'Ethna; il seroit
peut-etre possible d'y en rencontrer des morceaux aussi gros que ceux
que fournit l'isle de Ferroe. Quoique cette substance semble ici
appartenir aux laves, je ne dirai cependant point que toutes les
zeolites soient volcaniques, ou unies a des matieres volcaniques; celles
que l'on trouve en Allemagne sont, dit-on, dans des circonstances
differentes; mais je doit annoncer que je n'ai trouve cette substance en
Sicile, que dans les seules laves qui evidemment ont coule dans la mer,
et qui out ete recouvertes par ses eaux. La zeolite des laves n'est
point une dejection volcanique, ni une production du feu, ni meme un
matiere que les laves aient enveloppee lorsqu'elles etoient fluides;
elle est le resultat d'une operation et d'une combinaison posterieure,
auxquelles les eaux de la mer ont concouru. Les laves qui n'ont pas ete
submergees, n'en contiennent jamais. J'ai trouve ces observations si
constantes, que par-tout ou je rencontrois de la zeolite, j'etois sur
de trouver d'autres preuves de submersion, et partout ou je voyois des
laves recouvertes des depots de l'eau, j'etois sur de trouver de la
zeolite, et un de ces faits m'a toujours indique l'autre. Je me suis
servi avec succes de cette observation pour diriger mes recherches, et
pour connoitre l'antiquite des laves. _Mineralogie de Volcans, par
M. Faujas de Saint-Fond_. Here would appear to be the distinction of
subterraneous lava, in which zeolite and calcareous spar may be found,
and that which has flowed from a volcano, in which neither of these are
ever observed.]

There can be no doubt that these two different species of bodies have
had the same origin, and that they are composed of the same materials
nearly; but from the different circumstances Of their production, there
is formed a character to these bodies, by which, they may be perfectly
distinguished. The difference of those circumstances consists in this;
the one has been emitted to the atmosphere in its fluid state the other
only came to be exposed to the light in a long course of time, after it
had congealed under the compression of an immense load of earth, and
after certain operations, proper to the mineral regions, had been
exercised upon the indurated mass. This is the cause of the difference
between those erupted lavas, and our whin-stone, toad-stone, and the
Swedish trap, which may be termed subterraneous lava. The visible
effects of those different operations may now be mentioned.

In the erupted lavas, those substances which are subject to calcine and
vitrify in our fires, suffer similar changes, when delivered from a
compression which had rendered them fixed, though in an extremely heated
state. Thus, a lava in which there is much calcareous spar, when it
comes to be exposed to the atmosphere, or delivered from the compressing
force of its confinement, effervesces by the explosion of its fixed
air; the calcareous earth, at the same time, vitrifies with the other
substances. Hence such violent ebullition in volcanos, and hence the
emission of so much pumice-stone and ashes, which are of the same
nature.

In the body of our whin-stone, on the contrary, there is no mark of
calcination or vitrification. We frequently find in it much calcareous
spar, or the _terra calcarea aerata_, which had been in a melted state
by heat, and had been crystallized by congelation into a sparry form.
Such is the _lapis amygdaloides_, and many of our whin-stone rocks,
which contain pebbles crystallized and variously figured, both
calcareous, siliceous, and of a mixture in which both these substances
form distinct parts. The specimens of this kind, which I have from the
whin-stone or porphyry rock of the Calton-hill, exhibit every species
of mineral operation, in forming jasper, figured agate, and marble; and
they demonstrate, that this had been performed by heat or fusion.

I do not mean to say, that this demonstration is direct; it is
conditional, and proceeds upon the supposition, that the basaltic or
porphyry rock, in which those specimens are found, is a body which had
been in a melted state. Now, this is a supposition for which I have
abundance of evidence, were it required; but naturalists are now
sufficiently disposed to admit that proposition; they even draw
conclusions from this fact, which, I think, they are not sufficiently
warranted in doing; that is, from this appearance, they infer the former
existence of volcanos in those places. For my part, though I have made
the most strict examination, I never saw any vestige of such an event.
That there are, in other countries, evident marks of volcanos which
have been long extinguished, is unquestionably true; but naturalists,
imagining that there are no other marks of subterraneous fire and
fusion, except in the production of a lava, attribute to a volcano, as
a cause, these effects, which only indicate the exertion of that power
which might have been the cause of a volcano.

If the theory now given be just, a rock of marble is no less a mark
of subterraneous fire and fusion, than that of the basaltes; and the
flowing of basaltic streams among strata broken and displaced, affords
the most satisfactory evidence of those operations by which the body of
our land had been elevated above the surface of the sea; but it gives no
proof that the eruptive force of mineral vapours had been discharged in
a burning mountain. Now, this discharge is essential in the proper idea
of a volcano.

Besides this internal mark of an unerupted lava in the substance of the
stone or body of the flowing mass, there are others which belong to it
in common with all other mineral strata, consolidated by subterraneous
fire, and changed from the place of their original formation; this is,
the being broken and dislocated, and having veins of foreign matter
formed in their separations and contractions.

If these are mineral operations, proper to the lower regions of the
earth, and exerted upon bodies under immense compression, such things
will be sometimes found in the unerupted lavas, as well as in the
contiguous bodies with which they are associated. If, on the contrary,
these are operations proper to the surface of the earth, where the
dissolving power of water and air take place, and where certain
stalactical and ferruginous concretions are produced by these means;
then, in erupted lavas, we should find mineral concretions, which
concretions should be denied to bodies which had been consolidated at
the bottom of the sea; that is to say, where, without the operation of
subterraneous fire, no changes of that kind could have taken place, as
has already been observed. But in the unerupted species of lava, that
is to say, in our whin-stone, every species of mineral appearance is
occasionally to be found. Let those who have the opportunity to examine,
say, what arc to be found in proper lavas, that is, those of the erupted
kind. Sir William Hamilton informed me, when I showed him those mineral
veins and spars in our whin-stone, that he had never observed the like,
in lavas We have now formed some conclusions with regard to the nature
and production of those parts of the land of this globe which we
have had the means of examining perfectly; but; from the accounts of
travellers, and from, the specimens which are brought to us from distant
parts, we have reason to believe, that all the rest of the earth is
of the same nature with that which has been now considered. The great
masses of the earth are the same every where; and all the different
species of earths, of rocks or stone, which have as yet appeared, are to
be found in the little space of this our island.

It is true, that there are peculiar productions in the mineral kingdom
which are rare, as being found only in few places; but these things are
merely accidental in relation to the land, for they belong in property
to those parts of the mineral region which we never see. Such are, the
diamond of the east, the platina of the west, and the tin of Cornwall,
Germany, and Sumatra. Gold and silver, though found in many countries,
do not appear to be immediately necessary in the production of a
habitable country. Iron, again, is universal in the operations of the
globe, and is found often in that profusion which equals its utility.
Between these two extremes, we find all other minerals, that is to say,
here and there in moderate quantity, and apparently in some proportion
to their use. But all these substances are to be considered as the
vapours of the mineral regions, condensed occasionally in the crevices
of the land; and it is only the rocks and strata (in which those mineral
veins are found) that are now examined with regard to their original
composition, at the bottom of the sea, as well as to that, operation by
which those bodies had been indurated in their substance, and elevated
from the place in which they had been formed.

Thus, we have sufficient reason to believe, that, in knowing the
construction of the land in Europe, we know the constitution of the land
in every part of the globe. Therefore, we may proceed to form general
conclusions, from the knowledge of the mineral region, thus acquired in
studying those parts which are seen.

Having thus found, _first_, That the consolidated and indurated masses
of our strata had suffered the effects of violent heat and fusion;
_2dly_, That those strata, which had been formed in a regular manner at
the bottom of the sea, have been violently bended, broken, and removed
from their original place and situation; and, _lastly_, Having now found
the most indubitable proof, that the melting, breaking, and removing
power of subterraneous fire, has been actually exerted upon this land
which we examine, we cannot hesitate in ascribing these operations as a
cause to those effects which are exposed to our view. Now, these may be
considered as consisting in the solid state and present situation of
those stratified bodies, originally formed by subsidence in the ocean;
appearances which cannot, in reason, be ascribed to any other cause, and
which, upon this principle, are perfectly explained.

It is not meant to specify every particular in the means employed by
nature for the elevation of our land. It is sufficient to have shown,
that there is, in nature, means employed for the consolidating of
strata, formed originally of loose and incoherent materials; and that
those same means have also been employed in changing the place and
situation of those strata. But how describe an operation which man
cannot have any opportunity of perceiving? Or how imagine that, for
which, perhaps, there are not proper data to be found? We only know,
that the land is raised by a power which has for principle subterraneous
heat; but, how that land is preserved in its elevated station, is a
subject in which we have not even the means to form conjecture; at
least, we ought to be cautious how we indulge conjecture in a subject
where no means occur for trying that which is but supposition.

We now proceed, from the facts which have been properly established, to
reason with regard to the duration of this globe, or the general view of
its operations, as a living world, maintaining plants and animals.


SECTION IV.

System of Decay and Renovation observed in the Earth.

Philosophers observing an apparent disorder and confusion in the solid
parts of this globe, have been led to conclude, that there formerly
existed a more regular and uniform state, in the constitution of this
earth; that there had happened some destructive change; and that the
original structure of the earth had been broken and disturbed by some
violent operation, whether natural, or from a super-natural cause. Now,
all these appearances, from which conclusions of this kind have been
formed, find the most perfect explanation in the theory which we have
been endeavouring to establish; for they are the facts from whence we
have reasoned, in discovering the nature and constitution of this earth:
Therefore, there is no occasion for having recourse to any unnatural
supposition of evil, to any destructive accident in nature, or to the
agency of any preternatural cause, in explaining that which actually
appears.

It is necessary for a living or inhabited world, that this should
consist of land and water. It is also necessary, that the land should be
solid and stable, refilling, with great power, the violent efforts
of the ocean; and, at the same time, that this solid land should be
resolved by the influence of the sun and atmosphere, so as to decay,
and thus become a soil for vegetation. But these general intentions are
perfectly fulfilled in the constitution of our earth, which has been now
investigated. This great body being formed of different mixed masses,
having various degrees of hardness and solubility, proper soil for
plants is supplied from the gradual resolution of the solid parts;
fertility in those soils arises from the mixture of different elementary
substances; and stability is procured to that vegetable world, by the
induration of certain bodies, those rocks and stones, which protect the
softer masses of clay and soil.

In this manner, also, will easily be explained those natural appearances
which diversify the surface of the earth for the use of plants and
animals, and those objects which beautify the face of nature for the
contemplation of mankind. Such are, the distinctions of mountains and
valleys, of lakes and rivers, of dry barren deserts and rich watered
plains, of rocks which stand apparently unimpaired by the lapse of time,
and sands which fluctuate with the winds and tides. All these are the
effects of steady causes; each of these has its proper purpose in the
system of the earth; and in that system is contained another, which is
that of living growing bodies, and of animated beings.

But, besides this, man, the intellectual being, has, in this subject of
the mineral kingdom, the means of gratifying the desire of knowledge, a
faculty by which he is distinguished from the animal, and by which he
improves his mind in knowing causes. Man is not satisfied, like the
brute, in seeing things which are; he seeks to know how things have
been, and what they are to be. It is with pleasure that he observes
order and regularity in the works of nature, instead of being disgusted
with disorder and confusion; and he is made happy from the appearance of
wisdom and benevolence in the design, instead of being left to suspect
in the Author of nature, any of that imperfection which he finds in
himself.

Let us now take a view of that system of mineral economy, in which may
be perceived every mark of order and design, of provident wisdom and
benevolence.

We have been endeavouring to prove, that all the continents and islands
of this globe had been raised above the surface of the ocean; we have
also aimed at pointing out the cause of this translation of matter, as
well as of the general solidity of that which is raised to our view;
but however this theory shall be received, no person of observation can
entertain a doubt, that all, or almost all we see of this earth, had
been originally formed at the bottom of the sea. We have now another
object in our view; this is to investigate the operations of the globe,
at the time that the foundation of this land was laying in the waters of
the ocean, and to trace the existence and the nature of things, before
the present land appeared above the surface of the waters. We should
thus acquire some knowledge of the system according to which this world
is ruled, both in its preservation and production; and we might be thus
enabled to judge, how far the mineral system of the world shall appear
to be contrived with all the wisdom, which is so manifest in what are
termed the animal and vegetable kingdoms.

It must not be imagined that this undertaking is a thing unreasonable
in its nature; or that it is a work necessarily beset with any
unsurmountable difficulty; for, however imperfectly we may fulfill this
end proposed, yet, so far as it is to natural causes that are to be
ascribed the operations of former time, and so far as, from the present
state of things, or knowledge of natural history, we have it in our
power to reason from effect to cause, there are, in the constitution of
the world, which we now examine, certain means to read the annals of a
former earth.

The object of inquiry being the operations of the globe, during the time
that the present earth was forming at the bottom of the sea, we are now
to take a very general view of nature, without descending into those
particulars which so often occupy the speculations of naturalists, about
the present state of things. We are not at present to enter into any
discussion with regard to what are the primary and secondary mountains
of the earth; we are not to consider what is the first, and what the
last, in those things which now are seen; whatever is most ancient in
the strata which we now examine, is supposed to be collecting at the
bottom of the sea, during the period concerning which we are now to
inquire.

We have already considered those operations which had been necessary
in forming our solid land, a body consisting of materials originally
deposited at the bottom of the ocean; we are now to investigate the
source from whence had come all those materials, from the collection of
which the present land is formed; and from knowing the state in
which those materials had existed, previously to their entering the
composition of our strata, we shall learn something concerning the
natural history of this world, while the present earth was forming in
the sea.

We have already observed, that all the strata of the earth are composed
either from the calcareous relicts of sea animals, or from the
collection of such materials as we find upon our shores. At a gross
computation, there may perhaps be a fourth part of our solid land, which
is composed from the matter that had belonged to those animals. Now,
what a multitude of living creatures, what a quantity of animal economy
must have been required for producing a body of calcareous matter
which is interspersed throughout all the land of the globe, and which
certainly forms a very considerable part of that mass! Therefore, in
knowing how those animals had lived, or with what they had been fed, we
shall have learned a most interesting part of the natural history of
this earth; a part which it is necessary to have ascertained, in order
to see the former operations of the globe, while preparing the materials
of the present land. But, before entering upon this subject, let us
examine the other materials of which our land is formed.

Gravel forms a part of those materials which compose our solid land; but
gravel is no other than a collection of the fragments of solid stones
worn round, or having their angular form destroyed by agitation in
water, and the attrition upon each other, or upon similar hard bodies.
Consequently, in finding masses of gravel in the composition of our
land, we must conclude, that there had existed a former land, on which
there had been transacted certain operations of wind and water, similar
to those which are natural to the globe at present, and by which new
gravel is continually prepared, as well as old gravel consumed or
diminished by attrition upon our shores.

Sand is the material which enters, perhaps in greatest quantity, the
composition of our land. But sand, in general, is no other than small
fragments of hard and solid bodies, worn or rounded more or less by
attrition; consequently, the same natural history of the earth, which
is investigated from the masses of gravel, is also applicable to those
masses of sand which we find forming so large a portion of our present
land throughout all the earth[16].

[Note 16: Sand is a term that denotes no particular substance; although
by it is commonly meant a siliceous substance, as being by far the most
prevalent. Sand is one of the modifications, of size and shape, in a
hard body or solid substance, which may be infinitely diversified. The
next modification to be distinguished in mineral bodies is that of
gravel; and this differs in no respect from sand, except in point of
size. Next after gravel, in the order of ascent, come stones; and these
bear nearly the same relation to gravel as gravel does to sand. Now,
by stones is to be understood the fragments of rocks or solid mineral
bodies; and there is a perfect gradation from those stones to sand.
I have already endeavoured to explain the formation of those stony
substances; and now I am treating of a certain system of circulation,
which is to be found among minerals.

M. de Luc censures me for not giving the origin of sand, of which I form
the strata of the earth. He seems to have misunderstood my treatise. I
do not pretend, as he does in his theory, to describe the beginning of
things; I take things such as I find them at present, and from these
I reason with regard to that which must have been. When, from a thing
which is well known, we explain another which is less so, we then
investigate nature; but when we imagine things without a pattern or
example in nature, then, instead of natural history, we write only
fable.

M. de Luc, in the letter already mentioned, says, "that sand may be, and
I think it is, a substance which has formed _strata_ by _precipitation
in a liquid_." This is but an opinion, which may be either true or
false. If it be true, it is an operation of the mineral kingdom of which
I am ignorant. In all the sand which I have ever examined, I have never
seen any that might not be referred to the species of mineral substance
from which it had been formed. When this author shall have given us
any kind of information with regard to the production of sand _by
precipitation in a liquid_, it will then be time enough to think of
forming the strata of the earth with that sand.]

Clay is now to be considered as the last of those materials of which
our strata are composed; but, in order to understand the nature of this
ingredient, something must be premised.

Clay is a mixture of different earths or hard substances, in an
impalpable state. Those substances are chiefly the siliceous and
aluminous earths. Other earths are occasionally mixed in clays, or
perhaps always to be found in some small portion. But this does not
affect the general character of clay; it only forms a special variety in
the subject. A sensible or considerable portion of calcareous earth, in
the composition of clay, constitutes a marl, and a sufficient admixture
of sand, a loam.

An indefinite variety of those compositions of clay form a large portion
of the present strata, all indurated and consolidated in various
degrees; but this great quantity of siliceous, argillaceous, and
other compound substances, in form of earth or impalpable sediment,
corresponds perfectly with that quantity of those same substances which
must have been prepared in the formation of so much gravel and sand, by
the attrition of those bodies in the moving waters.

Therefore, from the consideration of those materials which compose the
present land, we have reason to conclude, that, during the time this
land was forming, by the collection of its materials at the bottom of
the sea, there had been a former land containing materials similar to
those which we find at present in examining the earth. We may also
conclude, that there had been operations similar to those which we
now find natural to the globe, and necessarily exerted in the actual
formation of gravel, sand, and clay. But what we have now chiefly in
view to illustrate is this, that there had then been in the ocean a
system of animated beings, which propagated their species, and which
have thus continued their several races to this day.

In order to be convinced of that truth, we have but to examine the
strata of our earth, in which we find the remains of animals. In this
examination, we not only discover every genus of animal which at present
exists in the sea, but probably every species, and perhaps some species
with which at present we are not acquainted. There are, indeed,
varieties in those species, compared with the present animals which we
examine, but no greater varieties than may perhaps be found among the
same species in the different quarters of the globe. Therefore, the
system of animal life, which had been maintained in the ancient sea, had
not been different from that which now subsists, and of which it belongs
to naturalists to know the history.

It is the nature of animal life to be ultimately supported from matter
of vegetable production. Inflammable matter may be considered as the
_pabulum_ of life. This is prepared in the bodies of living plants,
particularly in their leaves exposed to the sun and light. This
inflammable matter, on the contrary, is consumed in animal bodies, where
it produces heat or light, or both. Therefore, however animal matter, or
the pabulum of life, may circulate through a series of digesting powers,
it is constantly impaired or diminishing in the course of this economy,
and, without the productive power of plants, it would finally be
extinguished.[17]

[Note 17: See Dissertations on different subjects of Natural Philosophy,
part II.]

The animals of the former world must have been sustained during
indefinite successions of ages. The mean quantity of animal matter,
therefore, must have been preserved by vegetable production, and the
natural waste of inflammable substance repaired with continual addition;
that is to say, the quantity of inflammable matter necessary to the
animal consumption, must have been provided by means of vegetation.
Hence we must conclude, that there had been a world of plants, as well
as an ocean replenished with living animals.

We are now, in reasoning from principles, come to a point decisive of
the question, and which will either confirm the theory, if it be just,
or confute our reasoning, if we have erred. Let us, therefore, open
the book of Nature, and read in her records, if there had been a world
bearing plants, at the time when this present world was forming at the
bottom of the sea.

Here the cabinets of the curious are to be examined; but here some
caution is required, in order to distinguish things perfectly different,
which sometimes are confounded.

Fossil wood, to naturalists in general, is wood dug up from under
ground, without inquiring whether this had been the production of the
present earth, or that which had preceded it in the circulation of land
and water. The question is important, and the solution of it is, in
general, easy. The vegetable productions of the present earth, however
deep they may be found buried beneath its surface, and however ancient
they may appear, compared with the records of our known times, are new,
compared with the solid land on which they grew; and they are only
covered with the produce of a vegetable soil, or the alluvion of the
present land on which we dwell, and on which they had grown. But the
fossil bodies which form the present subject of inquiry, belonged to
former land, and are found only in the sea-born strata of our present
earth. It is to these alone that we appeal, in order to prove the
certainty of former events.

Mineralised wood, therefore, is the object now inquired after; that wood
which had been lodged in the bottom of the sea, and there composed part
of a stratum, which hitherto we have considered as only formed of the
materials proper to the ocean. Now, what a profusion of this species of
fossil wood is to be found in the cabinets of collectors, and even in
the hands of lapidaries, and such artificers of polished stones! In some
places, it would seem to be as common as the agate.

I shall only mention a specimen in my own collection. It is wood
petrified with calcareous earth, and mineralised with pyrites. This
specimen of wood contains in itself, even without the stratum of stone
in which it is embedded, the most perfect record of its genealogy.
It had been eaten or perforated by those sea worms which destroy the
bottoms of our ships. There is the clearest evidence of this truth.
Therefore, this wood had grown upon land which flood above the level of
sea, while the present land was only forming at the bottom of the ocean.

Wood is the most substantial part of plants, as shells are the more
permanent part of marine animals. It is not, however, the woody part
alone of the ancient vegetable world that is transmitted to us in
the record of our mineral pages. We have the type of many species
of foliage, and even of the most delicate flower; for, in this way,
naturalists have determined, according to the Linnaean system, the
species, or at least the genus, of the plant. Thus, the existence of a
vegetable system at the period now in contemplation, so far from being
doubtful, is a matter of physical demonstration.

The profusion of this vegetable matter, delivered into the ocean, which
then generated land, is also evidenced in the amazing quantities of
mineral coal which is to be found in perhaps every region of the earth.

Nothing can be more certain, than that all the coaly or bituminous
strata have had their origin from the substance of vegetable bodies
that grew upon the land. Those strata, tho', in general, perfectly
consolidated, often separate horizontally in certain places; and there
we find the fibrous or vascular structure of the vegetable bodies.
Consequently, there is no doubt of fossil coal being a substance
of vegetable production, however animal substances also may have
contributed in forming this collection of oleaginous or inflammable
matter.

Having thus ascertained the state of a former earth, in which plants
and animals had lived, as well as the gradual production of the present
earth, composed from the materials of a former world, it must be
evident, that here are two operations which are necessarily consecutive.
The formation of the present earth necessarily involves the destruction
of continents in the ancient world; and, by pursuing in our mind the
natural operations of a former earth, we clearly see the origin of that
land, by the fertility of which, we, and all the animated bodies of the
sea, are fed. It is in like manner, that, contemplating the present
operations of the globe, we may perceive the actual existence of those
productive causes, which are now laying the foundation of land in the
unfathomable regions of the sea, and which will, in time, give birth to
future continents.

But though, in generalising the operations of nature, we have arrived at
those great events, which, at first sight, may fill the mind with
wonder and with doubt, we are not to suppose, that there is any violent
exertion of power, such as is required in order to produce a great event
in little time; in nature, we find no deficiency in respect of time, nor
any limitation with regard to power. But time is not made to flow in
vain; nor does there ever appear the exertion of superfluous power, or
the manifestation of design, not calculated in wisdom to effect some
general end.

The events now under consideration may be examined with a view to see
this truth; for it may be inquired, Why destroy one continent in order
to erect another? The answer is plain; Nature does not destroy a
continent from having wearied of a subject which had given pleasure, or
changed her purpose, whether for a better or a worse; neither does she
erect a continent of land among the clouds, to show her power, or to
amaze the vulgar man; Nature has contrived the productions of vegetable
bodies, and the sustenance of animal life, to depend upon the gradual
but sure destruction of a continent; that is to say, these two
operations necessarily go hand in hand. But with such wisdom has nature
ordered things in the economy of this world, that the destruction of one
continent is not brought about without the renovation of the earth in
the production of another; and the animal and vegetable bodies, for
which the world above the surface of the sea is leveled with its bottom,
are among the means employed in those operations, as well as the
sustenance of those living beings is the proper end in view.

Thus, in understanding the proper constitution of the present earth, we
are led to know the source from whence had come all the materials which
nature had employed in the construction of the world which appears; a
world contrived in consummate wisdom for the growth and habitation of a
great diversity of plants and animals; and a world peculiarly adapted
to the purposes of man, who inhabits all its climates, who measures its
extent, and determines its productions at his pleasure.

The whole of a great object or event fills us with wonder and
astonishment, when all the particulars, in the succession of which the
whole had been produced, may be considered without the least emotion.
When, for example, we behold the pyramids of Egypt, our mind is agitated
with a crowd of ideas that highly entertains the person who understands
the subject; but the carrying a heavy stone up to the top of a hill or
mountain would give that person little pleasure or concern. We wonder at
the whole operation of the pyramid, but not at any one particular part.

The raising up of a continent of land from the bottom of the sea, is an
idea that is too great to be conceived easily in all the parts of its
operations, many of which are perhaps unknown to us; and, without being
properly understood, so great an idea may appear like a thing that is
imaginary. In like manner, the co-relative, or corresponding operation,
the destruction of the land, is an idea that does not easily enter into
the mind of man in its totality, although he is daily witness to part of
the operation. We never see a river in a flood, but we must acknowledge
the carrying away of part of our land, to be sunk at the bottom of the
sea; we never see a storm upon the coast, but we are informed of a
hostile attack of the sea upon our country; attacks which must, in time,
wear away the bulwarks of our soil, and sap the foundations of our
dwellings. Thus, great things are not understood without the analysing
of many operations, and the combination of time with many events
happening in succession.

Let us now consider what is to be the subject of examination, and where
it is that we are to observe those operations which must determine
either the stability or the instability of this land on which we live.

Our land has two extremities; the tops of the mountains, on the one
hand, and the sea-shores, on the other: It is the intermediate space
between these two, that forms the habitation of plants and animals.
While there is a sea-shore and a higher ground there is that which is
required in the system of the world: Take these away, and there would
remain an aqueous globe, in which the world would perish. But, in the
natural operations of the world, the land is perishing continually; and
this is that which now we want to understand.

Upon the one extremity of our land, there is no increase, or there is no
accession of any mineral substance. That place is the mountain-top, on
which nothing is observed but continual decay. The fragments of the
mountain are removed in a gradual succession from the highest station to
the lowest. Being arrived at the shore, and having entered the dominion
of the waves, in which they find perpetual agitation, these hard
fragments, which had eluded the resolving powers natural to the surface
of the earth, are incapable of resisting the powers here employed for
the destruction of the land. By the attrition of one hard body upon
another, the moving stones and rocky shore, are mutually impaired. And
that solid mass, which of itself had potential liability against the
violence of the waves, affords the instruments of its own destruction,
and thus gives occasion to its actual instability.

In order to understand the system of the heavens, it is necessary to
connect together periods of measured time, and the distinguished places
of revolving bodies. It is thus that system may be observed, or wisdom,
in the proper adapting of powers to an intention. In like manner, we
cannot understand the system of the globe, without seeing that progress
of things which is brought about in time, thus measuring the natural
operations of the earth with those of the heavens. This is properly the
business of the present undertaking.

Our object is to know the time which had elapsed since the foundation of
the present continent had been laid at the bottom of the ocean, to the
present moment in which we speculate on these operations. The space is
long; the data for the calculations are, perhaps, deficient: No matter;
so far as we know our error, or the deficiency in our operation, we
proceed in science, and shall conclude in reason. It is not given to man
to know what things are truly in themselves, but only what those things
are in his thought. We seek not to know the precise measure of any
thing; we only understand the limits of a thing, in knowing what it is
not, either on the one side or the other.

We are investigating the age of the present earth, from the beginning of
that body which was in the bottom of the sea, to the perfection of its
nature, which we consider as in the moment of our existence; and we have
necessarily another aera, which is collateral, or correspondent, in the
progress of those natural events. This is the time required, in the
natural operations of this globe, for the destruction of a former
earth; an earth equally perfect with the present and an earth equally
productive of growing plants and living animals. Now, it must appear,
that, if we had a measure for the one of those corresponding operations,
we would have an equal knowledge of the other.

The formation of a future earth being in the bottom of the ocean, at
depths unfathomable to man, and in regions far beyond the reach of his
observation, here is a part of the process which cannot be taken as a
principle in forming an estimate of the whole. But, in the destruction
of the present earth, we have a process that is performed within the
limits of our observation; therefore, in knowing the measure of this
operation, we shall find the means of calculating what had passed on a
former occasion, as well as what will happen in the composition of a
future earth. Let us, therefore, now attempt to make this estimate of
time and labour.

The highest mountain may be levelled with the plain from whence it
springs, without the loss of real territory in the land; but when the
ocean makes encroachment on the basis of our earth, the mountain,
unsupported, tumbles with its weight; and with the accession of hard
bodies, moveable with the agitation of the waves, gives to the sea the
power of undermining farther and farther into the solid basis of our
land. This is the operation which is to be measured; this is the mean
proportional by which we are to estimate the age of worlds that have
terminated, and the duration of those that are but beginning.

But how shall we measure the decrease of our land? Every revolution of
the globe wears away some part of some rock upon some coast; but the
quantity of that decrease, in that measured time, is not a measurable
thing. Instead of a revolution of the globe, let us take an age. The age
of man does no more in this estimate than a single year. He sees,
that the natural course of things is to wear away the coast, with the
attrition of the sand and stones upon the shore; but he cannot find a
measure for this quantity which shall correspond to time, in order to
form an estimate of the rate of this decrease.

But man is not confined to what he sees; he has the experience of former
men. Let us then go to the Romans and the Greeks in search of a measure
of our coasts, which we may compare with the present state of things.
Here, again, we are disappointed; their descriptions of the shores of
Greece and of Italy, and their works upon the coast, either give no
measure of a decrease, or are not accurate enough for such a purpose.

It is in vain to attempt to measure a quantity which escapes our notice,
and which history cannot ascertain; and we might just as well attempt to
measure the distance of the stars without a parallax, as to calculate
the destruction of the solid land without a measure corresponding to the
whole.

The description which Polybius has given of the Pontus Euxinus, with
the two opposite Bosphori, the Meotis, the Propontis, and the Port of
Byzantium, are as applicable to the present state of things as they were
at the writing of that history. The filling up of the bed of the
Meotis, an event which, to Polybius, appeared not far off, must also be
considered as removed to a very distant period, though the causes still
continue to operate as before.

But there is a thing in which history and the present state of things do
not agree. It is upon the coast of Spain, where Polybius says there was
an island in the mouth of the harbour of New Carthage. At present, in
place of the island, there is only a rock under the surface of the
water. It must be evident, however, that the loss of this small island
affords no proper ground of calculation for the measure or rate of
wasting which could correspond to the coast in general; as neither
the quantity of what is now lost had been measured, nor its quality
ascertained.

Let us examine places much more exposed to the fury of the waves and
currents than the coast of Carthagena, the narrow fretum, for example,
between Italy and Sicily. It does not appear, that this passage is
sensibly wider than when the Romans first had known it. The Isthmus of
Corinth is also apparently the same at present as it had been two or
three thousand years ago. Scilla and Charibdis remain now, as they had
been in ancient times, rocks hazardous for coasting vessels which had to
pass that strait.

It is not meant by this to say, these rocks have not been wasted by the
sea, and worn by the attrition of moving bodies, during that space of
time; were this true, and that those rocks, the bulwarks of the land
upon those coasts, had not been at all impaired from that period, they
might remain for ever, and thus the system of interchanging the place of
sea and land upon this globe might be frustrated. It is only meant
to affirm, that the quantity which those rocks, or that coast, have
diminished from the period of our history, has either been too small
a thing for human observation, or, which is more probable, that no
accurate measurement of the subject, by which this quantity of decrease
might have been ascertained, had been taken and recorded. It must be
also evident, that a very small operation of an earthquake would be
sufficient to render every means of information, in this manner of
mensuration, unsatisfactory or precarious.

Pliny says Italy was distant from Sicily a mile and a half; but we
cannot suppose that this measure was taken any otherwise than by
computation, and such a measure is but little calculated to afford us
the just means of a comparison with the present distance. He also says,
indeed, that Sicily had been once joined with Italy. His words are:
"Quondam Brutio agro cohaerens, mox interfuso mari avulsa.[18]" But all
that we can conclude from this history of Pliny is, that, in all times,
to people considering the appearances of those two approached coasts,
it had seemed probable, that the sea formed a passage between the two
countries which had been once united; in like manner as is still more
immediately perceived, in that smaller disjunction which is made between
the island of Anglesey and the continent of Wales.

[Note 18: Lib. 3. cap. 8.]

The port of Syracuse, with the island which forms the greater and
lesser, and the fountain of Arethusa, the water of which the ancients
divided from the sea with a wall, do not seem to be altered. From Sicily
to the coast of Egypt, there is an uninterrupted course of sea for a
thousand miles; consequently, the wind, in such a stretch of sea, should
bring powerful waves against those coasts: But, on this coast of Egypt,
we find the rock on which was formerly built the famous tower of Pharos;
and also, at the eastern extremity of the port Eunoste, the sea-bath,
cut in the solid rock upon the shore. Both those rocks, buffeted
immediately with the waves of the Mediterranean sea, are, to all
appearance, the same at this day as they were in ancient times.[19]

[Note 19: Lettres sur l'Egypte, M. Savary.]

Many other such proofs will certainly occur, where the different parts
of those coasts are examined by people of observation and intelligence.
But it is enough for our present purpose, that this decrease of the
coasts in general has not been observed; and that it is as generally
thought, that the land is gaining upon the sea, as that the sea is
gaining upon the land.

To sum up the argument, we are certain, that all the coasts of the
present continents are wasted by the sea, and constantly wearing away
upon the whole; but this operation is so extremely slow, that we cannot
find a measure of the quantity in order to form an estimate: Therefore,
the present continents of the earth, which we consider as in a state of
perfection, would, in the natural operations of the globe, require a
time indefinite for their destruction.

But, in order to produce the present continents, the destruction of a
former vegetable world was necessary; consequently, the production of
our present continents must have required a time which is indefinite.
In like manner, if the former continents were of the same nature as the
present, it must have required another space of time, which also is
indefinite, before they had come to their perfection as a vegetable
world.

We have been representing the system of this earth as proceeding with
a certain regularity, which is not perhaps in nature, but which is
necessary for our clear conception of the system of nature. The
system of nature is certainly in rule, although we may not know every
circumstance of its regulation. We are under a necessity, therefore, of
making regular suppositions, in order to come at certain conclusions
which may be compared with the present state of things.

It is not necessary that the present land should be worn away and
wasted, exactly in proportion as new land shall appear; or, conversely,
that an equal proportion of new land should always be produced as the
old is made to disappear. It is only required, that at all times, there
should be a just proportion of land and water upon the surface of the
globe, for the purpose of a habitable world.

Neither is it required in the actual system of this earth, that every
part of the land should be dissolved in its structure, and worn away by
attrition, so as to be floated in the sea. Parts of the land may often
sink in a body below the level of the sea, and parts again may be
restored, without waiting for the general circulation of land and water,
which proceeds with all the certainty of nature, but which advances with
an imperceptible progression. Many of such apparent irregularities may
appear without the least infringement on the general system. That system
is comprehended in the preparation of future land at the bottom of the
ocean, from those materials which the dissolution and attrition of
the present land may have provided, and from those which the natural
operations of the sea afford.

In thus accomplishing a certain end, we are not to limit nature with the
uniformity of an equable progression, although it be necessary in our
computations to proceed upon equalities. Thus also, in the use of means,
we are not to prescribe to nature those alone which we think suitable
for the purpose, in our narrow view. It is our business to learn of
nature (that is by observation) the ways and means, which in her wisdom
are adopted; and we are to imagine these only in order to find means for
further information, and to increase our knowledge from the examination
of things which actually have been. It is in this manner, that intention
may be found in nature; but this intention is not to be supposed, or
vainly imagined, from what we may conceive to be.

We have been now supposing, that the beginning of our present earth had
been laid in the bottom of the ocean, at the completion of the former
land; but this was only for the sake of distinctness. The just view is
this, that when the former land of the globe had been complete, so as
to begin to waste and be impaired by the encroachment of the sea, the
present land began to appear above the surface of the ocean. In this
manner we suppose a due proportion to be always preserved of land and
water upon the surface of the globe, for the purpose of a habitable
world, such as this which we possess. We thus, also, allow time and
opportunity for the translation of animals and plants to occupy the
earth.

But, if the earth on which we live, began to appear in the ocean at
the time when the last began to be resolved, it could not be from the
materials of the continent immediately preceding this which we examine,
that the present earth had been constructed; for the bottom of the ocean
must have been filled with materials before land could be made to appear
above its surface.

Let us suppose that the continent, which is to succeed our land, is at
present beginning to appear above the water in the middle of the Pacific
Ocean, it must be evident, that the materials of this great body, which
is formed and ready to be brought forth, must have been collected from
the destruction of an earth, which does not now appear. Consequently,
in this true statement of the case, there is necessarily required the
destruction of an animal and vegetable earth prior to the former land;
and the materials of that earth which is first in our account, must have
been collected at the bottom of the ocean, and begun to be concocted for
the production of the present earth, when the land immediately preceding
the present had arrived at its full extent.

This, however, alters nothing with regard to the nature of those
operations of the globe. The system is still the same. It only protracts
the indefinite space of time in its existence, while it gives us a view
of another distinct period of the living world; that is to say, the
world which we inhabit is composed of the materials, not of the earth
which was the immediate predecessor of the present, but of the earth
which, in ascending from the present, we consider as the third, and
which had preceded the land that was above the surface of the sea, while
our present land was yet beneath the water of the ocean. Here are three
distinct successive periods of existence, and each of these is, in our
measurement of time, a thing of indefinite duration.

We have now got to the end of our reasoning; we have no data further
to conclude immediately from that which actually is: But we have got
enough; we have the satisfaction to find, that in nature there is
wisdom, system, and consistency. For having, in the natural history of
this earth, seen a succession of worlds, we may from this conclude that
there is a system in nature; in like manner as, from seeing revolutions
of the planets, it is concluded, that there is a system by which they
are intended to continue those revolutions. But if the succession of
worlds is established in the system of nature, it is in vain to look for
any thing higher in the origin of the earth. The result, therefore, of
this physical inquiry is, that we find no vestige of a beginning,--no
prospect of an end.



CHAPTER II.

An Examination of Mr KIRWAN'S Objections to the Igneous Origin of Stony


 


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