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
Substances.
A theory which is founded on a new principle, a theory which has to make
its way in the public mind by overturning the opinions commonly received
by philosophising men, and one which has nothing to recommend it but the
truth of its principles, and the view of wisdom or design to which it
leads, neither of which may perhaps be perceived by the generality of
people, such a theory, I say, must meet with the strongest opposition
from the prejudices of the learned, and from the superstition of those
who judge not for themselves in forming their notions, but look up to
men of science for authority. Such is the case with some part of the
Theory of the Earth, which I have given, and which will probably give
offence to naturalists who have espoused an opposite opinion. In order,
then, to obtain the approbation of the public, it may not be enough to
give a theory that should be true, or altogether unexceptionable it may
be necessary to defend every point that shall be thought exceptionable
by other theorists, and to show the fallacy of every learned objection
that may be made against it. It is thus, in general, that truth and
error are forced to struggle together, in the progress of science; and
it is only in proportion as science removes erroneous conceptions, which
are necessarily in the constitution of human knowledge, that truth will
find itself established in natural philosophy.
Mr Kirwan has written a dissertation, entitled, _Examination of the
Supposed Igneous Origin of Stony Substances_, which was read in the
Royal Irish Academy. The object of that dissertation is to state certain
objections, which have occurred to him, against the Theory of the Earth
published in the Transactions of the Edinburgh Royal Society; and he has
attacked that theory in all the points where it appears to him to be
vulnerable. It is to these objections that I am now to give an answer.
The authority given to this dissertation, by the Royal Irish Academy,
as well as the reputation of the author, make it necessary for me
to endeavour to put in their true light the facts alleged in that
performance, and to analyse the arguments employed, in order to judge of
the reasoning by which the theory of mineral fusion is refuted in this
Examination.
A theory founded on truth, and formed according to the proper rules of
science, can ever suffer from a strict examination, by which it would
be but the more and more confirmed. But, where causes are to be traced
through a chain of various complicated effects, an examination not
properly conducted upon accurate analytical principles, instead of
giving light upon a subject in which there had been obscurity and doubt,
may only serve to perplex the understanding, and bring confusion into a
subject which was before sufficiently distinct. To redress that evil,
then, must require more labour and some address; and this is an
inconveniency that may be looked for, more or less, in every
controversial discussion.
I do not mean to enter any farther into the defence of my theory in
this chapter, than what is necessary to answer a man of science and
respectability, who has stated his objections. The observations which
he has made appear to me to be founded on nothing more than common
prejudice, and misconceived notions of the subject. I am therefore
to point out that erroneous train of reasoning, into which a hasty
superficial view of things, perhaps, has led the patron of an opposite
opinion to see my theory in an unfavourable light. This, however, is not
all; for, that train of inconsequential reasoning is so congenial with
the crude and inconsiderate notion generally entertained, of solid
mineral bodies having been formed by the infiltration of water into
the earth, that no opportunity should be lost of exposing an erroneous
manner of reasoning, which is employed in supporting a hypothesis
founded upon certain operations of the surface of this earth that cannot
be properly applied to the formation of mineral bodies. This object,
therefore, so far as it may come in the way, will be attended to in
this discussion, although I shall have another opportunity of farther
enlarging upon that subject.
Our author begins by examining a geological operation, the very opposite
to that of mineral consolidation, and which would seem to have little
connection with the subject of this dissertation. In my theory, I
advanced two propositions with regard to the economy of this world:
First, That the solid masses of this earth, when exposed to the
atmosphere, decay, and are resolved into loose materials, of which the
vegetable soil upon the surface is in part composed; and, secondly, That
these loose materials are washed away by the currents of water, and
thus carried at last into the sea. Our author says "Here are two
suppositions, neither of which is grounded on facts;" and yet he has
but the moment before made the following confession: "That the soil,
however, receives an increase from some species of stones that moulder
by exposition to the air cannot be denied, but there is no proof that
all soil has arisen from decomposition."--Surely _all soil_, that
is made from the _hard and compact_ body of the land, which is my
proposition, must have arisen from _decomposition_; and I have no where
said, that _all_ the soil of this earth is made from the decomposition
or detritus of those stony substances; for, masses of looser sand and
softer substances contribute still more to the formation of vegetable
soils.
With regard to the other proposition, our author says, "Soil is not
constantly carried away by the water, even from mountains."--I have not
said that it is _constantly_ washed away; for, while it is soil in which
plants grow, it is not travelling to the sea, although it be on the road,
and must there arrive in time. I have said, that it is _necessarily_
washed away, that is, occasionally. M. de Luc's authority is then
referred to, as refuting this operation of water and time upon the soil.
Now, I cannot help here observing, that our author seems to have as
much misapprehended M. de Luc's argument as he has done mine. That
philosopher, in his letters to the Queen, has described most accurately
the decay of the rocks and solid mountains of the Alps and Jura, and the
travelling of their materials by water, although he does not carry them
to the sea. It is true, indeed, that this author, who supposes the
present earth on which we dwell very young, is anxious to make an earth,
_in time_, that shall not decay nor be washed away at all; but that time
is not come yet; therefore the authority, here given against my
theory, is the speculative supposition, or mere opinion, of a natural
philosopher, with regard to an event which may never come to pass, and
which I shall have occasion to consider fully in another place.
Our author had just now said, that I have advanced two suppositions,
_neither of which is grounded on facts_: Now, with regard to the one, he
has acknowledged, that the mouldering of stones takes place, which is
the fact on which that proposition is grounded; and with regard to the
other, the only authority given against it is founded expressly upon
the moving of soil by means of the rain water, in order to make sloping
plains of mountains. Here, therefore, I have grounded my propositions
upon facts; and our author has founded his objections, first, upon a
difficulty which he has himself removed; and, secondly, upon nothing but
a visionary opinion, with regard to an earth which is not yet made, and
which, when once made, is never more to change.
After making some unimportant observations,--of all water not flowing
into the sea,--and of the travelled materials being also deposited upon
the plains, etc. our author thus proceeds: "Hence the conclusion of our
author relative to the imperfect constitution of the globe falls to the
ground; and the pains he takes to learn, _by what means a decayed world
may be renovated_, are superfluous."--The object of my theory is
to show, that this decaying nature of the solid earth is the very
_perfection_ of its constitution, as a living world; therefore, it
was most proper that I should _take pains to learn_ by what means the
decayed parts might be renovated. It is true, indeed, that this will be
superfluous, when once that constitution of the earth, which M. de Luc
thinks is preparing, shall be finished; but, in the mean time, while
rivers carry the materials of our land, and while the sea impairs the
coast, I may be allowed to suppose that this is the actual constitution
of the earth.
I cannot help here animadverting upon what seems to be our author's
plan, in making these objections, which have nothing to do with his
examination. He accuses me of giving this world a false or imperfect
constitution, (in which the solid land is considered as resolvable, and
the materials of that land as being washed away into the sea,) for no
other reason, that I can see, but because this may imply the formation
of a future earth, which he is not disposed to allow; and, he is now to
deny the stratified construction of this present earth to have been made
by the deposits of materials at the bottom of the sea, because that
would prove the existence of a former earth, which is repugnant to his
notion of the origin of things, and is contrary, as he says, to reason,
and the tenor of the Mosaic history. Let me observe, in passing, that M.
de Luc, of whose opinions our author expresses much approbation, thinks
that he proves, from the express words and tenor of the Mosaic history,
that the present earth was at the bottom of the sea not many years ago,
and that the former earth had then disappeared.
But, what does our author propose to himself, in refusing to admit my
view of the operations which are daily transacting upon the surface of
this earth, where there is nothing dark or in the least mysterious, as
there may be in the mineral regions? Does he mean to say, that it is not
the purpose of this world to provide soil for plants to grow in? Does
he suppose that this soil is not moveable with the running water of the
surface? and, Does he think that it is not necessary to replace that
soil which is removed? This is all that I required in that constitution
of the world which he has thus attacked; and I wish that he or any
person would point out, in what respect I had demanded any thing
unreasonable, or any thing that is not actually to be observed every
day.
Thus I have endeavoured to show, that our author has attacked my theory
in a part where I believe it must be thought invulnerable; but this is
only, I presume, in order that he may make an attack with more advantage
upon another part, viz. the composition of strata from the materials of
an earth thus worn out in the service of vegetation,--materials which
are necessarily removed in order to make way for that change of things
in which consists the active and living system of this world. If he
succeed in this attempt to refute my theory of the original formation
of strata, he would then doubtless find it more easy to persuade
philosophers that the means which I employ in bringing those materials
again to light, when transformed into such solid masses as the system of
this earth requires, are extravagant, unnatural, and unnecessary. Let us
then see how he sets about this undertaking.
With regard to the composition of the earth, it is quoted from my
theory, that _the solid parts of the globe are in general composed
of sand, gravel, argillaceous and calcareous strata, or of various
compositions of these with other substances_; our author then adds,
"This certainly cannot be affirmed as a fact, but rather the contrary;
it holds only true of the surface, the basis of the greater part of
Scotland is evidently a granitic rock, to say nothing of the continents,
both of the Old and New World, according to the testimony of all
mineralogists." This proposition, with regard to the general composition
of the earth, I have certainly not assumed, I have maintained it as a
fact, after the most scrupulous examination of all that, with the most
diligent search, I have been able to see, and of all that authors
have wrote intelligibly upon the subject. If, therefore, I have so
misrepresented this great geological fact on which my theory is
absolutely founded, I must have erred with open eyes; and my theory
of the earth, like others which have gone before it, will, upon close
examination, appear to be unfounded, as the dissertation now before us
is endeavouring to represent it.
Our author here, I think, alleges that the contrary to this, my
fundamental proposition, is the truth; and he has given us Scotland as
an example in which his assertion (founded upon the testimony of all
mineralogists), is illustrated. Now my geological proposition should
certainly be applicable to Scotland, which is the country that I ought
to be best acquainted with; consequently, if what our author here
asserts be true, I would have deserved that blame which he is willing to
throw on me. Let me then beg the readers attention for a moment, that I
may justify myself from that charge, and place in its proper light this
authority, upon so material a point in geology.
I had examined Scotland from the one end to the other before I saw one
stone of granite in its native place, I have moreover examined almost
all England and Wales, (excepting Devonshire and Cornwall) without
seeing more of granite than one spot, not many hundred yards of extent;
this is at Chap; and I know, from information, that there is another
small spot in the middle of England where it is just seen. But, let me
be more particular with regard to Scotland, the example given in proof.
I had travelled every road from the borders of Northumberland and
Westmoreland to Edinburgh; from Edinburgh, I had travelled to
Port-Patrick, and from that along the coast of Galloway and Airshire
to Inverary in Argyleshire, and I had examined every spot between the
Grampians and the Tweedale mountains from sea to sea, without seeing
granite in its place. I had also travelled from Edinburgh by Grief,
Rannock, Dalwhiny, Fort Augustus, Inverness, through east Ross and
Caithness, to the Pentland-Frith or Orkney islands, without seeing one
block of granite in its place. It is true, I met with it on my return
by the east coast, when I just saw it, and no more, at Peterhead and
Aberdeen; but that was all the granite I had ever seen when I wrote
my Theory of the Earth. I have, since that time, seen it in different
places; because I went on purpose to examine it, as I shall have
occasion to describe in the course of this work.
I may now with some confidence affirm, from my own observation, and from
good information with regard to those places where I have not been,
except the northwest corner, I may affirm, I say, that instead of the
basis of the greatest part of Scotland being a granitic rock, which our
author has maintained as an evident thing, there is very little of it
that is so; not perhaps one five hundred part. So far also as I am to
judge from my knowledge of the mineral construction of England and
Wales, which I have examined with the greatest care, and from the
mineral chart which my friend Mr Watt made for me from his knowledge of
Cornwall, I would say that there is scarcely one five hundred part
of Britain that has granite for its basis. All the rest, except the
porphyry and basaltes, consists of stratified bodies, which are composed
more or less of the materials which I mentioned, generally, in the above
quotation, and which our author would dispute.
But do not let me take the advantage of this error of our author with
regard to the mineralogy of Scotland, and thus draw what may be thought
an undue conclusion in favour of my general theory; let us go over and
examine the continent of Europe, and see if it is any otherwise there
than in Britain. From the granite of the Ural mountains, to that which
we find in the Pyrenees, there is no reason, so far as I have been able
to learn, to conclude that things are formed either upon any other
principle, or upon a different scale. But, instead of one five hundred
part, let us suppose there to be one fiftieth part of the earth in
general resting upon granite, I could not have expressed myself
otherwise than I have done; for, when I maintained that the earth in
general consisted of stratified bodies, I said that this was only _nine
tenths, or perhaps ninety-nine hundredths_ of the whole, and I mentioned
that there were other masses of a different origin, which should be
considered separately. Our author, on the contrary, asserts that the Old
and New Worlds, as well as Scotland, are placed upon granite as a basis,
which he says is according to the testimony of all mineralogists.
I shall have occasion to examine this opinion of mineralogists, in
comparing it with those masses of granite which appear to us; and I hope
fully to refute the geological, as well as mineralogical notions with
regard to that body. In the mean time, let me make the following
reflection, which here naturally occurs.
My Theory of the Earth is here examined,--not with the system of
nature, or actual state of things, to which it certainly should have
corresponded,--but with the systematic views of a person, who has formed
his notions of geology from the vague opinion of others, and not from
what he has seen. Had the question been, How far my theory agreed with
other theories, our author might very properly have informed his readers
that it was diametrically opposite to the opinions of mineralogists;
but, this was no reason for concluding it to be erroneous; on the
contrary, it is rather a presumption that I may have corrected the error
of mineralogists who have gone before me, in like manner as it is most
reasonable to presume that our author may have corrected mine. Let us
then proceed to examine how far this shall appear to be the case.
Our author has stated very fairly from the Theory, viz. _That all the
strata of the earth, not only those consisting of calcareous masses, but
others superincumbent on these, have had their origin at the bottom
of the sea, by the collection of sand, gravel, shells, coralline, and
crustaceous bodies, and of earths and clays variously mixed, separated,
and accumulated._ He then adds, "Various geological observations
contradict this conclusion. There are many stratified mountains of
argillaceous slate, gneiss, serpentine, jasper, and even marble, in
which either sand, gravel, shells, coralline, or crustaceous bodies are
never, or scarce ever found."
Here our author seems to have deceived himself, by taking a very partial
view of things which should be fully examined, and well understood,
before general conclusions are to be drawn from those appearances; for,
although those particular objects may not be visible in the strata which
he has enumerated, or many others, they are found in those strata which
are either immediately connected and alternated with them, or with
similar strata; something to that purpose I think I have said; and, if
I had not, it certainly requires no deep penetration to have seen this
clear solution of that appearance of those objects not being found in
every particular stratum. He says that those marks of known materials
are never or scarce ever found;--by _scarce ever_ he surely means that
they are sometimes found; but if they shall only _once_ be found, his
argument is lost. I have not drawn my geological conclusion from every
particle in strata being distinguishable, but from there being certain
distinguishable particles in strata, and from our knowing what had been
the former state and circumstances of those distinguished parts.
If every stone or part of a stratum, in which those known objects are
not immediately visible, must be considered as so _many geological
observations that contradict my theory_, (of strata being formed from
the materials of a former earth), then, surely every stone and every
stratum which visibly contains any of those materials, must prove my
theory. But if every stratum, where these are found in any part of it,
is to be concluded as having had its origin at the bottom of the sea;
and, if every concomitant stratum, though not having those objects
visible or sufficiently distinct, must be considered as having had the
same or a similar origin, that pretended contradiction of my theory
comes to no more than this, that every individual stone does not bear
in it the same or equal evidence of that general proposition which
necessarily results from the attentive consideration of the whole,
including every part.
But to see how necessary it is to judge in this manner, not partially,
but upon the whole, we may observe, that there are two ways by which the
visible materials or distinguishable bodies of a former earth, not only
_may_ be rendered invisible in the composition of our present earth,
but _must_ be so upon many occasions. These are, _first_, by mechanical
comminution, which necessarily happens, more or less, in that operation
by which bodies are moved against one another, and thus transported from
the land to the bottom of the deepest seas; _secondly_, by chemical
operations, (whatever these may be, whether the action of water or of
fire, or both), which are also necessarily employed for consolidating
those loose materials, that are to form the rocks and stones of
this earth, and by means of which those materials are to have their
distinguishable shapes affected in all degrees and obliterated.
Therefore, to demand the visible appearance of those materials in every
stratum of the earth, or in every part of a stratum, is no other than to
misunderstand the subject altogether. The geological observations,
which have been thus alleged as contradicting my theory, are stratified
bodies, containing proofs of the general origin which I attribute to the
earth, but proofs which may not always be seen with equal facility as
those which even convince the vulgar.
Our author has surely perplexed himself with what writers of late have
said concerning primitive mountains as they are called, a subject of
deeper search, than is commonly imagined, as I hope to show in the
course of this work. It is an interesting subject of investigation,
as giving us the actual view of those operations of nature which, in
forming my Theory of the Earth, more general principles had led me to
conclude _might be_. But, it is a subject which, I am afraid, will lead
me to give farther offence to our author, however innocent I may be in
giving nothing but what I have from nature.
The reason for saying so is this; I am blamed for having endeavoured
to trace back the operations of this world to a remote period, by the
examination of that which actually appears, contrary, as is alleged,
"to reason, and the tenor of the Mosaic history, thus leading to an
abyss, from which human reason recoils, etc." In a word, (says our
author), "to make use of his own expression, _We find no vestige of
a beginning._ Then this system of successive worlds must have been
eternal." Such is the logic by which, I suppose, I am to be accused of
atheism. Our author might have added, that I have also said--_we see
no prospect of an end_; but what has all this to do with the idea of
eternity? Are we, with our ideas of _time_, (or mere succession), to
measure that of eternity, which never succeeded any thing, and which
will never be succeeded? Are we thus to measure eternity, that boundless
thought, with those physical notions of ours which necessarily limit
both space and time? and, because we see not the beginning of created
things, Are we to conclude that those things which we see have always
been, or been without a cause? Our author would thus, inadvertently
indeed, lead himself into that gulf of irreligion and absurdity into
which, he alleges, I have _boldly plunged_.
In examining this present earth, we find that it must have had its
origin at the bottom of the sea, although our author seems willing to
deny that proposition. Farther, in examining the internal construction
of this stratified and sea-born mass, we find that it had been composed
of the moved materials of a former earth; and, from the most accurate
and extensive examination of those materials, which in many places are
indeed much disguised, we are led necessarily to conclude, that there
had been a world existing, and containing an animal, a vegetable, and a
mineral system. But, in thus tracing back the natural operations which
have succeeded each other, and mark to us the course of time past, we
come to a period in which we cannot see any farther. This, however,
is not the beginning of those operations which proceed in time and
according to the wise economy of this world; nor is it the establishing
of that, which, in the course of time, had no beginning; it is only the
limit of our retrospective view of those operations which have come to
pass in time, and have been conducted by supreme intelligence.
My principal anxiety was to show how the constitution of this world
had been wisely contrived; and this I endeavoured to do, not from
supposition or conjecture, but from its answering so effectually the end
of its intention, viz. the preserving of animal life, which we cannot
doubt of being its purpose. Here then is a world that is not eternal,
but which has been the effect of wisdom or design.
With regard again to the prospective view of the creation, How are we to
see the end of that wise system of things which so properly fulfils the
benevolent intention of its maker,--in giving sustenance to the animal
part, and information to intellectual beings, who, in these works of
nature, read what much concerns their peace of mind,--their intellectual
happiness? What then does our author mean, in condemning that
comprehensive view which I have endeavoured to take of nature? Would he
deny that there is to be perceived wisdom in the system of this world,
or that a philosopher, who looks into the operations of nature, may not
plainly read the power and wisdom of the Creator, without recoiling, as
he says, from the abyss? The abyss, from which a man of science should
recoil, is that of ignorance and error.
I have thus shown, that, from not perceiving the wise disposition of
things upon the surface of this earth for the preservation of vegetable
bodies, our author has been led to deny the necessary waste of the
present earth, and the consequent preparation of materials for the
construction of another; I have also shown, that he denies the origin
which I had attributed to the stratified parts of this earth, as having
been the collection of moving materials from a former earth; and now
I am come to consider the professed purpose of this paper, viz. the
examination of solid stony substances which we find in those strata
of our earth, as well as in more irregular masses. Here, no doubt, my
theory would have been attacked with greater success, had our author
succeeded in pointing out its error with regard to the original
composition of those indurated bodies, to which I ascribe fusion as the
cause of their solidity. For, if we should, according to our author's
proposition, consider those consolidated bodies as having been
originally formed in that solid state, here the door might be shut
against any farther investigation;--But to what purpose?--Surely not to
refute my theory, but to explode every physical inquiry farther on the
subject, and thus to lead us back into the science of darkness and of
scepticism. But let us proceed to see our author's sentiments on this
subject.
As I had proved from matter of fact, or the actual appearances of
nature, that all the strata of the earth had been formed at the bottom
of the sea, by the subsidence of those materials which either come from
the decaying land, or are formed in the sea itself, it was necessary
that I should consider in what manner those spongy or porous bodies of
loose materials, gathered together at the bottom of the sea, could have
acquired that consolidated state in which we find them, now that they
are brought up to our examination. Upon this occasion, our author says,
"The particles which now form the solid parts of the globe need not be
supposed to have originally been either spongy or porous, the interior
parts at the depth of a few miles might have been originally, as at
present, a solid mass." If, indeed, we shall make that supposition, we
may then save ourselves the trouble of considering either how the strata
of the earth have been formed or consolidated; for, they might have been
so originally. But, how can a naturalist who had ever seen a piece of
Derbyshire marble, or any other shell limestone, make that supposition?
Here are, to the satisfaction of every body of common understanding who
looks at them, bodies which are perfectly consolidated, bodies which
have evidently been formed at the bottom of the sea, and therefore which
were not originally a solid mass. Mr Bertrand, it is true, wrote a book
to prove that those appearances were nothing but a _lusus naturae_; and,
I suppose he meant, with our author, that those strata had been also
originally, as at present, a solid mass.
With regard to the consolidation of strata, that cardinal point for
discussion, our author gives the following answer: "Abstracting from his
own gratuitous hypothesis, it is very easy to satisfy our author on this
head; the concreting and consolidating power in most cases arises from
the mutual attraction of the component particles of stones to each
other." This is an answer with regard to the _concreting power_, a
subject about which we certainly are not here inquiring. Our author,
indeed, has mentioned a _consolidating power_; but that is an improper
expression; we are here inquiring, How the interstices, between the
collected materials of strata, deposited at the bottom of the sea, have
been filled with a hard substance, instead of the fluid water which had
originally occupied those spaces. Our author then continues; "If these
particles leave any interstices, these are filled with water, which no
ways obstructs their solidity when the points of contact are numerous;
hence the decrepitation of many species of stones when heated."
If I understand our author's argument, the particles of stone are, by
their mutual attractions, to leave those hard and solid bodies which
compose the strata, that is to say, those hard bodies are to dissolve
themselves; but, To what purpose? This must be to fill up the
interstices, which we must suppose occupied by the water. In that case,
we should find the original interstices filled with the substances which
had composed the strata, and we should find the water translated into
the places of those bodies; here would be properly a transmutation, but
no consolidation of the strata, such as we are here to look for, and
such as we actually find among those strata. It may be very easy for
our author to form those explanations of natural phenomena; it costs
no tedious observation of facts, which are to be gathered with labour,
patience, and attention; he has but to look into his own fancy, as
philosophers did in former times, when they saw the abhorrence of a
vacuum and explained the pump. It is thus that we are here told the
consolidation of strata _arises from the mutual attraction of the
component particles of stones to each other_; the power, by which the
particles of solid stony bodies retain their places in relation to each
other, and resist separation from the mass, may, no doubt, be properly
enough termed their mutual attractions; but we are not here inquiring
after that power; we are to investigate the power by which the particles
of hard and stony bodies had been separated, contrary to their mutual
attractions, in order to form new concretions, by being again brought
within the spheres of action in which their mutual attractions might
take place, and make them one solid body. Now, to say that this is by
their mutual attraction, is either to misunderstand the proper question,
or to give a most preposterous answer.
It is not every one who is fit to reason with regard to abstract general
propositions; I will now, therefore, state a particular case, in
illustration of that proposition which has been here so improperly
answered. The strata of Derbyshire marbles were originally immense
collections at the bottom of the sea, of calcareous bodies consisting
almost wholly of various fragments of the _entrochi_; and they were then
covered with an indefinite number of other strata under which these
_entrochi_ must have been buried. In this original state of those
strata, I suppose the interstices between the fragments of the coralline
bodies to have been left full of sea-water; at present we find those
interstices completely filled with a most perfectly solid body of
marble; and the question is, whether that consolidating operation
has been the work of water and solution, by our naturalist's termed
infiltration; or if it has been performed, as I have maintained, by the
softening power or heat, or introduction of matter in the fluid state
of fusion. Our author does not propose any other method for the
consolidation of those loose and incoherent bodies, but he speaks of the
_mutual attraction of the component particles of stone to each other_;
Will that fill the interstices between the coralline bodies with solid
marble, as well as consolidate the coralline bodies themselves? or, if
it should, How are those interstices to be thus filled with a substance
perfectly different from the deposited bodies, which is also frequently
the case? But, how reason with a person who, with this consolidation of
strata, confounds the well known operation by which the mortar, made
with caustic lime and sand, becomes a hard body! One would imagine
that he were writing to people of the last age, and not to chemical
philosophers who know so well how that mortar is concreted.
To my argument, That these porous strata are found _consolidated with
every different species of mineral substance_, our author makes the
following observation: "Here the difficulties to the supposition of an
aqueous solution are placed in the strongest light; yet it must be owned
that they partly arise from the author's own gratuitous supposition,
that strata existed at the bottom of the sea previous to their
consolidation;"--gratuitous supposition!--so far from being a
supposition of any kind, it is a self evident proposition; the terms
necessarily imply the conclusion. I beg the readers attention for a
moment to this part of our author's animadversion, before proceeding to
consider the whole; for, this is a point so essential in my theory,
that if it be a gratuitous supposition, as is here asserted, it would
certainly be in vain to attempt to build upon it the system of a world.
That strata may exist, whether at the bottom of the sea, or any other
where, without being consolidated, will hardly be disputed; for, they
are actually found consolidated in every different degree. But, when
strata are found consolidated, at what time is it that we are to suppose
this event to have taken place, or this accident to have happened to
them?--Strata are formed at the bottom of water, by the subsidence or
successive deposits of certain materials; it could not therefore
be during their formation that such strata had been consolidated;
consequently, we must necessarily _conclude_, without any degree of
_supposition_, that _strata had existed at the bottom of the sea
previous to their consolidation_, unless our author can show how they
may have been consolidated previous to their existing.
This then is what our author has termed a gratuitous supposition of
mine, and which, he adds, "is a circumstance which will not be allowed
by the patrons of the aqueous origin of stony substances, as we have
already seen."--I am perfectly at a loss to guess at what is here
alluded to _by having been already seen_, unless it be that which I have
already quoted, concerning things which have been never seen, that
is, _those interior parts of the earth which were originally a solid
mass_.--I have hardly patience to answer such reasoning;--a reasoning
which is not founded upon any principle, which holds up nothing
but chimera to our view, and which ends in nothing that is
intelligible;--but, others, perhaps, may see this dissertation of our
author's in a different light; therefore, it is my duty to analyse the
argument, however insignificant it may seem to me.
I have minutely examined all the stratified bodies which I have been
able, during a lifetime, to procure, both in this country of Britain,
and from all the quarters of the globe; and the result of my inquiry has
been to conclude, that there is nothing among them in an original state,
as the reader will see in the preceding chapter. With regard again to
the masses which are not stratified, I have also given proof that they
are not in their original state, such as granite, porphyry, serpentine,
and basaltes; and I shall give farther satisfaction, I hope, upon that
head, in the course of this work. I have therefore concluded, That there
is nothing to be found in an original state, so far as we see, in the
construction of this earth. But, our author answers, That the interior
parts _might have been in an original state of solidity_.--So might
they have been upon the surface of the earth, or on the summits of our
mountains; but, we are not inquiring What they _might have been_, but
What they truly _are_. It is from this actual state in which the solid
parts of the earth are found, that I have endeavoured to trace back the
different states in which they must have been; and, by generalising
facts, I have formed a theory of the earth. If this be a wrong principle
or manner of proceeding in a physical investigation, or if, proceeding
upon that principle, I have made the induction by reasoning improperly
on any occasion, let this be corrected by philosophers, who may reason
more accurately upon the subject. But to oppose a physical investigation
with this proposition, _that things might have been otherwise_, is to
proceed upon a very different principle,--a principle which, instead of
tending to bring light out of darkness, is only calculated to extinguish
that light which we may have acquired.
I shall afterwards have occasion to examine how far the philosophers,
who attribute to aqueous solution the origin of stony substances, have
proceeded in the same inductive manner of reasoning from effect to
cause, as they ought to do in physical subjects, and not by feigning
causes, or following a false analogy; in the mean time, I am to answer
the objections which have been made to the theory of the earth.
In opposition to the theory of consolidating bodies by fusion, our
author has taken great pains to show, that I cannot provide materials
for such a fire as would be necessary, nor find the means to make it
burn had I those materials. Had our author read attentively my theory he
would have observed, that I give myself little or no trouble about that
fire, or take no charge with regard to the procuring of that power, as I
have not founded my theory on the _supposition_ of subterraneous
fire, however that fire properly follows as a conclusion from those
appearances on which the theory is founded. My theory is founded upon
the general appearances of mineral bodies, and upon this, that mineral
bodies must necessarily have been in a state of fusion. I do not pretend
to prove, demonstratively, that they had been even hot, however that
conclusion also naturally follows from their having been in fusion. It
is sufficient for me to demonstrate, That those bodies must have been,
more or less, in a state of softness and fluidity, without any species
of solution. I do not say that this fluidity had been without heat;
but, if that had been the case, it would have answered equally well the
purpose of my theory, so far as this went to explain the consolidation
of strata or mineral bodies, which, I still repeat, must have been
by simple fluidity, and not by any species of solution, or any other
solvent than that universal one which permeates all bodies, and which
makes them fluid.
Our author has justly remarked the difficulty of fire burning below the
earth and sea. It is not my purpose here to endeavour to remove those
difficulties, which perhaps only exist in those suppositions which are
made on this occasion; my purpose is to show, that he had no immediate
concern with that question, in discussing the subject of the
consolidation which we actually find in the strata of the earth, unless
my theory, with regard to the igneous origin of stony substances, had
proceeded upon the supposition of a subterraneous fire. It is surely one
thing to employ fire and heat to melt mineral bodies, in supposing this
to be the cause of their consolidation, and another thing to acknowledge
fire or heat as having been exerted upon mineral bodies, when it is
clearly proved, from actual appearances, that those bodies had been in
a melted state, or that of simple fluidity. Here are distinctions which
would be thrown away upon the vulgar; but, to a man of science, who
analyses arguments, and reasons strictly from effect to cause, this is,
I believe, the proper way of coming at the truth. If the patrons of
the aqueous origin of stony substances can give us any manner of
scientifical, _i.e._ intelligible investigation of that process, it
shall be attended to with the most rigid impartiality, even by a patron
of the igneous origin of those substances, as he wishes above all things
to distinguish, in the mineral operations, those which, on the one hand,
had been the effect of water, from those which, on the other hand, had
been the immediate effect of fire or fusion;--this has been my greatest
study. But, while mineralists or geologists give us only mere opinions,
What is science profited by such inconsequential observations, as are
founded upon nothing but our vulgar notions? Is the figure of the
earth, _e.g._ to be doubted, because, according to the common notion of
mankind, the existence of an antipod is certainly to be denied?
I am not avoiding to meet that question with regard to the providing
of materials for such a mineral fire as may be required; no question I
desire more to be asked to resolve; but it must not be in the manner
that our author has put that question. He has included this supposed
difficulty among a string of other arguments by which he would refute my
theory with regard to the igneous origin of stony substances, as if I
had made that fire a necessary condition or a principle in forming my
theory of consolidation. Now, it is precisely the reverse; and this is
what I beg that mineral philosophers will particularly attend to, and
not give themselves so much unnecessary trouble, and me so disagreeable
a talk. I have proved that those stony substances have been in the fluid
state of fusion; and from this, I have inferred the former existence of
an internal heat, a subterraneous fire, or a certain cause of fusion by
whatever name it shall be called, and by whatever means it shall have
been procured. The nature of that operation by which strata had been
consolidated, like that by which they had been composed, must, according
to my philosophy, be decided by ocular demonstration; from examining the
internal evidence which is to be found in those bodies as we see them in
the earth; because the consolidating operation is not performed in our
sight, no more than their stratification which our author has also
denied to have been made, as I have said, by the deposits of materials
at the bottom of the sea. Now, with regard to the means of procuring
subterraneous fire, if the consolidating operation shall be thus decided
to have been that of fusion, as I think I have fully shown, and for
which I have as many witnesses, perhaps as there are mineral bodies,
then our author's question, (how I am to procure a fire) in the way that
he has put it, as an argument against the fusion, would be at least
useless; for, though I should here confess my ignorance with regard to
the means of procuring fire, the evidence of the melting operation, or
former fluidity of those mineral bodies, would not be thereby in the
least diminished. If again no such evidence for the fusion of those
bodies shall appear, and it be concluded that they had been consolidated
by the action of water alone, as our author seems inclined to maintain,
he would have no occasion to start difficulties about the procuring of
fire, in order to refute a theory which then would fall of itself as
having no foundation.
But in order to see this author's notion of the theory which he is here
examining, it may be proper to give a specimen of his reasoning upon
this subject of heat. He says, "That my supposition of heat necessary
for consolidating strata is _gratuitous_, not only because it is
unnecessary, as we have already shown, but also because it is
inconsistent with our author's own theory." Let us now consider those
two propositions. _First_, it is unnecessary, _as we have already
shown_;--I have already taken particular notice of what we have been
shown on this occasion, viz. That the earth at a certain depth _may
have been originally in a solid state_; and, that, where it is to be
consolidated, this is done by the _mutual attraction of the stony
particles_. Here is all that we have been shown to make subterraneous
heat, for the consolidation of strata, unnecessary; and now I humbly
submit, if this is sufficient evidence, that mineral heat is a
gratuitous supposition.
Secondly, "_it is inconsistent with our author's own theory._" Here
I would beg the readers attention to the reasoning employed on
this occasion. He says, "according to him these strata, which were
consolidated by heat, were composed of materials gradually worn from a
preceding continent, casually and successively deposited in the sea;
Where then will he find, and how will he suppose, to have been formed
those enormous masses of sulphur, coal, or bitumen, necessary to produce
that immense heat necessary for the fusion of those vast mountains of
stone now existing? All the coal, sulphur, and bitumen, now known, does
not form the 100,000 part of the materials deposited within one quarter
of a mile under the surface of the earth; if, therefore, they were, as
his hypothesis demands, carried off and mixed with the other materials,
and not formed in vast and separate collections, they could never
occasion, by their combustion, a heat capable of producing the smallest
effect, much less those gigantic effects which he requires."
Here is a comparative estimate formed between two things which have not
any necessary relation; these are, the quantity of combustible materials
found in the earth, on the one hand, and the quantity which is supposed
necessary for hardening and consolidating strata, on the other. If this
earth has been consolidated by the burning of combustible materials,
there must have been a superfluity, so far as there is a certain
quantity of these actually found unconsumed in the strata of the earth.
Our author's conclusion is the very opposite; let us then see how he
is to form his argument, by which he proves that the supposition of
subterraneous heat for hardening bodies is gratuitous and unnecessary,
as being inconsistent with my theory.
According to my theory, the strata of this earth are composed of the
materials which came from a former earth; particularly these combustible
strata that contain plants which must have grown upon the land. Let
us then suppose the subterraneous fire supplied with its combustible
materials from this source, the vegetable bodies growing upon the
surface of the land. Here is a source provided for the supplying of
mineral fire, a source which is inexhaustible or unlimited, unless
we are to circumscribe it with regard to time, and the necessary
ingredients; such as the matter of light, carbonic matter, and the
hydrogenous principle. But it is not upon any deficiency of this kind
that our author founds his estimate; it is upon the superfluity of
combustible materials which is actually found in this earth, after it
had been properly consolidated and raised above the surface of the sea.
This is a method of reasoning calculated to convince only those who do
not understand it; it is as if we should conclude that a person had died
of want, because he had left provision behind him. Our author certainly
means to employ nothing but the combustible minerals of the present
earth, in feeding the subterraneous fire which is to concoct a future
earth; in that case, I will allow that his provision is deficient; but
this is not my theory.
I am not here to enter into any argument concerning subterraneous
fire; the reader will find, in the foregoing theory, my reasons for
concluding, That subterraneous fire had existed previous to, and ever
since, the formation of this earth,--that it exists in all its vigour
at this day,--that there is, in the constitution of this earth, a
superfluity of subterranean heat,--and that there is wisely provided a
proper remedy against any destructive effect to the system, that might
arise from that superabundant provision of this necessary agent. Had our
author attended to the ocular proof that we have of the actual existence
of subterraneous fire, and to the physical demonstrations which I have
given of the effects of heat in melting mineral bodies, he must have
seen that those arguments of his, with regard to the difficulty or
impossibility of procuring that fire, can only show the error of his
reasoning. I am far from supposing that my theory may be free from
inconsistency or error; I am only maintaining that, in all his confident
assertions, this author has not hitherto pointed any of these out.
So far I have answered our author's objections as to consolidation, and
I have given a specimen of his reasoning upon that subject; but with
regard to my Theory of the Earth, although simple fluidity, without
heat, would have answered the purpose of consolidating strata that had
been formed at the bottom of the sea, it was necessary to provide a
power for raising those consolidated strata from that low place to the
summits of the continents; now, in supposing heat to be the cause of
that fluidity which had been employed in the consolidation of those
submarine masses, we find a power capable of erecting continents, and
the only power, so far as I see, which natural philosophy can employ
for that purpose. Thus I was led, from the consolidation of strata, to
understand the nature of the elevating power, and, from the nature of
that power, again to understand the cause of fluidity by which the rocks
and stones of this earth had been consolidated.
Having thus, without employing the evidence of any fire or _burning_,
been necessarily led to conclude an extreme degree of heat exerted in
the mineral regions, I next inquire how far there are any appearances
from whence we might conclude whether that active subterraneous power
still subsists, and what may be the nature of that power. When first I
conceived my theory, naturalists were far from suspecting that basaltic
rocks were of volcanic origin; I could not then have employed an
argument from these rocks as I may do now, for proving that the fires,
which we see almost daily issuing with such force from volcanos, are a
continuation of that active cause which has so evidently been exerted
in all times, and in all places, so far as have been examined of this
earth.
With regard to the degree of heat in that subterraneous fire, our
author, after proving that combustible materials would not burn in the
mineral regions, then says, that suppose they were to burn, this would
be "incapable of forming a heat even equal to that of our common
furnaces, as Mr Dolomieu has clearly shown to be the case with respect
to volcanic heat." The place to which he alludes, I believe to be that
which I have quoted from the Journal de Physique (Part I. page 139) to
which I here beg leave to refer the reader. After what I have already
said, this subject will appear to be of little concern to me; but, it
must be considered, that my object, in these answers, is not so much to
justify the theory which I have given, as it is to remove that prejudice
which, to those who are not master of chemical and mineral subjects,
will naturally arise from the opinion or authority of a scientific man,
and a chemist; therefore, I think it my business to show how much he
has misconceived the matter which he treats of, and how much he
misunderstands the subject of my theory.
Mr Dolomieu alleges that the volcanic fire operates in the melting of
bodies, not by the intensity of its heat, which is the means employed by
us in our operations, but in the long continuance of its action. But in
that proposition, this philosopher is merely giving us his opinion; and,
this opinion our author mistakes, I suppose, for the fact on which that
opinion had been (perhaps reasonably) founded. The reader will see, in
the place quoted, or in the _avant-propos_ to his _Mémoire sur les Iles
Ponces_, the fact to be this; That the Chevalier Dolomieu finds those
bodies which we either cannot melt in our fires, or which we cannot melt
without changing them by calcination and vitrification, he finds, I say,
these substances had actually been melted with his lavas; he also finds
those substances, which are necessarily dissipated in our fires, to have
been retained in those melted mineral substances. Had our author quoted
the text, instead of giving us his own interpretation, he could not have
offered a stronger confirmation of my theory; which certainly is not
concerned with the particular intensity of volcanic fire, and far less
with what may be the opinion of any naturalist with regard to that
intensity, but only with the efficacy of that volcanic heat for the
melting of mineral substances. Now this efficacy of volcanic fire, so
far as we are to found upon the authority given on this occasion, is
clearly confirmed by the observations of a most intelligent mineralist,
and one who is actually a patron of the opposite theory to that which I
have given. This being the state of the case, Must I not conclude, that
our author has misunderstood the subject, and that he has been led to
give a mutilated opinion of Mr Dolomieu, in order to refute my theory,
when either the entire opinion, or the facts on which the opinion had
been founded, would have confirmed it?
I have thus endeavoured to put in its true light a species of reasoning,
which, while it assumes the air and form of that inductive train of
thought employed by men of science for the investigation of nature, is
only fit to mislead the unwary, and, when closely examined, will appear
to be inconsequential or unfounded. How mortifying then to find, that
one may be employed almost a lifetime in generalising the phenomena of
nature, or in gathering an infinity of evidence for the forming of a
theory, and that the consequence of this shall only be to give offence,
and to receive reproach from those who see not things in the same
light!--While man has to learn, mankind must have different opinions.
It is the prerogative of man to form opinions; these indeed are often,
commonly I may say, erroneous; but they are commonly corrected, and it
is thus that truth in general is made to appear.
I wrote a general Theory for the inspection of philosophers, who
doubtless will point out its errors; but this requires the study of
nature, which is not the work of a day; and, in this political age, the
study of nature seems to be but little pursued by our philosophers. In
the mean time, there are, on the one hand, sceptical philosophers, who
think there is nothing certain in nature, because there is misconception
in the mind of man; on the other hand, there are many credulous
amateurs, who go to nature to be entertained as we go to see a
pantomime: But there are also superficial reasoning men, who think
themselves qualified to write on subjects on which they may have read
in books,--subjects which they may have seen in cabinets, and which,
perhaps, they have just learned to name; without truly knowing what they
see, they think they know those regions of the earth which never can be
seen; and they judge of the great operations of the mineral kingdom,
from having kindled a fire, and looked into the bottom of a little
crucible.
In the Theory of the Earth which was published, I was anxious to warn
the reader against the notion that subterraneous heat and fusion could
be compared with that which we induce by our chemical operations
on mineral substances here upon the surface of the earth; yet,
notwithstanding all the precaution I had taken, our author has bestowed
four quarto pages in proving to me, that our fires have an effect upon
mineral substances different from that of the subterraneous power which
I would employ.
He then sets about combining metals with sulphur in the moist way, as if
that were any more to his purpose than is the making of a stalactite for
the explanation of marble. Silver and lead may be sulphurated, as he
says, with hepatic gas; but, Has the sulphurated solid ores of those
metals, and that of iron, been formed in the moist way, as in some
measure they may be by the fusion of our fires? But, even suppose that
this were the case, Could that explain a thousand other appearances
which are inconsistent with the operation of water? We see aerated lead
dissolved in the excavations of our mines, and again concreted by the
separation of the evaporated solvent, in like manner as stalactical
concretions are made of calcareous earth; but, so far from explaining
mineral appearances, as having had their concretions formed in the same
manner, here is the most convincing argument against it; for, among the
infinite variety of mineral productions which we find in nature, Why
does no other example of aqueous concretion ever occur upon the surface
of the earth except those which we understand so well, and which we
therefore know cannot be performed in the bodies of strata not exposed
to the evaporation of the solvent, a circumstance which is necessary.
I have given a very remarkable example of mineral fusion, in reguline
manganese, (as the reader will see in page 68.) It is not that this
example is more to the purpose of my theory than what may be found in
every species of stone; but this example speaks so immediately to
the common sense of mankind, (who are often convinced by a general
resemblance of things, when they may not see the force of demonstration
from an abstract principle) that I thought it deserved a place on that
account, as well as being a curious example, But more particularly to my
antagonist, who has been pleased (very improperly indeed) to try some
part of my theory in the fire, here is an example which should have
been absolutely in point, and without any manner of exception:--Has he
acknowledged this?--No; he has, on the contrary, endeavoured to set this
very example aside.
On this occasion, he says, "Manganese has been found in a reguline state
by M. de la Peyrouse, and in small grains, as when produced by fire.
True; but it was mixed with a large quantity of iron, which is often,
found in that form without any suspicion of fusion. A fire capable of
melting quartz might surely produce it in larger masses." We have here
a kind of two arguments, for removing the effect of this example; and I
shall consider them separately.
The first of these is, the not being suspected of having been in fusion;
now, if this were to be admitted as an argument against the igneous
origin of stony substances, it might have superseded the adducing of any
other, for it is applicable perhaps to every mineral; but we must here
examine the case more minutely.
This argument, of the manganese being in a mine of iron, if I understand
it rightly, amounts to this, that, as iron ore is not suspected of
having been melted, therefore, we should doubt the manganese having been
so. If this be our author's meaning, it is not the fair conclusion which
the case admits of; for, so far as the manganese appears evidently to
have been in a melted state, the iron ore should be _suspected_ of
having been also in fusion, were there no other evidence of that fact.
In science, however, it is not suspicion that should be employed in
physical investigation; the question at present is; If the phenomena of
the case correspond to the conclusion which the intelligent mineralist,
who examined them, has formed? and, to this question, our author gives
no direct answer. He says, _iron is often found in that form without any
suspicion of fusion_. This is what I am now to answer.
The form in which the manganese appears is one of the strongest proofs
of those masses having been in fusion; and, if iron should ever be found
in that form, it must give the same proof of mineral fusion as this
example of manganese; let us then see the nature of this evidence. The
form of the manganese is that of a fluid body collecting itself into a
spherical figure by the cohesion or attraction of its particles, so far
as may be admitted by other circumstances; but, being here refilled by
the solid part on which it rests, this spherical body is flattened by
the gravitation of its substance. Now here is a regular form, which
demonstrates the masses to have been in the state of fusion; for, there
is no other way in which that form of those reguline masses could have
been induced.