a startling and extravagant assertion. There has been, and still is, an
extreme sensitiveness in the minds of intelligent men on this subject. And
I highly respect the ground from which their apprehensions spring, viz., a
fear that to admit the great antiquity of the globe would bring discredit
upon revelation. And yet I believe the most candid and able theologians of
the present day do not fear that to admit the existence of the matter of
the world previous to the six days' work of creation, is inconsistent with
the Mosaic statement. But if we allow any period between its creation and
the six demiurgic days, it is no more derogatory to Scripture to make that
period ten millions of years than ten years. For if the sacred writer
would pass over ten years in silence, he could, with the same propriety,
pass over ten millions. Now, the longer I study geology, the nearer do my
ideas approximate to the latter number as a measure of the earth's
duration. Let us contemplate a few facts. We are able to trace the
geological changes that have taken place on the earth since man's
existence upon it with a good deal of accuracy. For since his remains are
found only in alluvium, we must regard all changes that took place
previous to the deposition of that formation to have been of an earlier
date than his creation. Now, what are the changes which the last six
thousand years have witnessed? In some places, the agency of rivers and
other causes have made an accumulation of alluvial matter to the depth of
not more than one or two hundred feet, although in particular places it is
several hundred feet. These deposits have been pushed forward at the
mouths of some large rivers, so as to cover hundreds, and even thousands,
of square miles. Oceanic currents have also made deposits in the bottom of
wide seas of considerable extent; and in some limited spots these
deposits have been consolidated into rock. The action of frost and
gravity, also, has crumbled from precipitous ledges angular fragments
enough to form a slope of detritus sometimes a hundred feet high. The
polyparia, or coral builders, have advanced their work only a few feet in
thickness during this period, and soils have accumulated in some places
about as much. Volcanic action has occasionally thrown up a new island
from the ocean's bed; but only a few of them have been permanent. Some
tracts of country, in no case more than a few hundred miles in extent,
have, by the same agency, been raised a few feet, or sunk down the same
amount. But after all, the earth's surface remains essentially the same as
when man was placed upon it.
Now, compare these slight changes with those which have preceded it,
through the operation of the same agencies, since the first existence of
animals upon the globe. I will not contend, with some distinguished
geologists, that these same changes have always operated with the same
intensity as at present. But there are several circumstances which show
that the depositions from water could not have been essentially different
in ancient and modern times. Now, just compare six or eight miles in
thickness of the fossiliferous deposits of the previous periods with the
two hundred feet of alluvium accumulated during the historic period; and,
after you have made all reasonable allowance for the greater intensity of
action in former times, you will still find yourselves confounded by the
incalculable time requisite to pile up such an immense thickness of
materials, and then to harden most of them into stone; especially when you
call to mind the numerous changes of organic life, and the vast amount of
animal remains which they exhibit. A superficial observer might lump such
a work, and crowd it into a few thousand years. But the more its details
are studied, the longer does the period appear that is requisite for its
production. Each successive investigation discovers new evidence of
changes in composition, or organic contents, or of vertical movements
effected by extremely slow agencies, so as to make the whole work
immeasurably long.
But when we have gone back to the commencement of animal existence on the
globe, we have taken but one step in our review of its early history. The
next backward step embraces that wide period during which the stratified,
non-fossiliferous rocks--far thicker than the fossiliferous--were
deposited; probably by the agency of fire and water. Or if we adopt the
metamorphic theory of Mr. Lyell, we shall be still more deeply impressed
by the length of that period, during which these rocks were in a course of
deposition, consolidation, and metamorphosis. For he supposes them
originally deposited from water, just as mud, sand, and gravel now are
accumulating in the ocean's bed, and to have enveloped organic beings, as
similar materials now do. Next the whole were consolidated, so as to form
the exact prototype of the existing fossiliferous rocks; and finally it
underwent almost complete fusion, by the slow propagation of internal heat
upwards, until all the organic contents were obliterated, and a
crystalline structure was substituted. Nay, according to this theory,
other systems of rocks, of an analogous character, may have preceded the
present primary stratified ones, and have been at length entirely melted
into the unstratified; so that we cannot say when organic life first began
on the globe. But I will not press this theory, because most of the ablest
geologists reject it, at least in its full extent. And we have a period
long enough to confound the imagination, if we take the common view, which
supposes the non-fossiliferous rocks to have been deposited from water,
at a temperature too high to admit the existence of organic beings.
We have now gone back to that point in the earth's history when a crust
had begun to form over the shoreless ocean of melted matter, of which we
have reason to suppose it was then composed. Shall we attempt to trace
back that history any farther? The light does, indeed, grow dim, and the
clew more and more uncertain, the farther we recede along the track of the
earth's existence. Still there are some scattered rays that seem to recall
to us a condition of the earth still earlier than that in which it
constituted a molten globe. It may have been dissipated into vapor, like a
comet, or a nebula; and subsequently, by the slow radiation of its heat,
have been condensed into an opaque, though a melted, incandescent mass.
Several analogies certainly throw an air of plausibility over this
hypothesis. And if such was, indeed, the earliest condition of the earth,
the time requisite to condense it into melted matter must have been longer
than any other period of its history.
Who, now, at all familiar with the dynamics of geological agencies, shall
undertake to give an arithmetical expression to the periods that make up
the world's entire history? Not only does the reasoning faculty fail to
grasp the entire sum, but even imagination, as she flies backwards through
period after period, tires in the effort, and brings back not even a
conjectural result. The same feeling does, in fact, come over the mind,
which she experiences when astronomy has hurried her from world to world,
from sun to sun, from system to system, from nebula to nebula, and yet she
seems no nearer to the limits of creation than when she started. We know
certainly that there are limits; because matter cannot be infinite. But we
cannot conjecture where they are fixed. We know, also that there was a
time when this world did not exist, an epoch when its entire mass was
spoken into existence by the fiat of Jehovah; because the Bible expressly
declares it. But that epoch is unrevealed. If there is any truth in
geology, it was certainly more than six thousand years ago. Nay, that
science carries us as far back into the arcana of time as astronomy does
into the arcana of space. Neither the distance in the one case, nor the
duration in the other, can be estimated. But there is a sublime
inspiration in the effort to grasp the subject; and I see not why there is
not as much grandeur and high gratification in the idea of vast duration
as of vast expansion. And I see not why we do not gain as much enlargement
of our conceptions of the plans of Jehovah respecting the universe in the
one case as in the other. We cannot but infer, from the pre-Adamic state
of our world, that it must have subserved other purposes than to sustain
its present inhabitants.
2. In the second place, geology gives us impressive examples of the extent
of organic life on the globe since its creation.
I shall not contend, with some geologists, that even the primary
crystalline rocks may once have been filled with organic remains, which
have been obliterated by heat; and that, in this way, there may have been
a number of creations of organized beings on the globe, of which no trace
now remains. I take as the basis of my argument only the relics of animals
and plants actually found in the rocks. And when one sees mountain masses,
often of small shells, and spread over wide areas, he is amazed to learn
how prolific nature has been. What a countless number of vegetables, too,
must have been required to produce beds of coal from one to fifty feet
thick, and extending over thousands of square miles, and alternating
several times with sandstone in the same basin! There is reason to
believe, too, that the number of animals preserved in the strata bears
only a small proportion to those which have been utterly destroyed and
decomposed into their original elements. For example, in the sandstone
along Connecticut River, the tracks of more than forty species of bipeds
and quadrupeds have been found most distinctly marked. Some of these
bipeds must have been of colossal size--as much as twelve or fifteen feet
in height. And yet scarcely any other vestige of their existence has been
discovered. They were the giant rulers of that valley for centuries; but
they have all vanished. How numerous, then, may have been the softer
animals of the ancient world, which have not left even a footmark to
certify their existence to coming generations!
But the facts recently brought to light respecting infusoria and
polythalamia fill us with the greatest admiration of the extent of organic
life upon the globe. We have already seen that some of these animals are
so minute that eight millions of them are found in a space not larger than
a mustard-seed; and yet they had skeletons of silex, lime, and iron; and,
of course, these skeletons have been preserved; and, though of the
smallest size, it requires not less than forty-one billions to make a
single cubic inch; yet deposits of them, or of species not much larger,
occur, several feet in thickness, and extending over several square miles.
Nay, the chalk of Northern Europe, and also of Western Asia, where it
constitutes most of Mount Lebanon, and extends southerly through Palestine
into Arabia and Egypt, and also deposits in North and South America,
thousands of miles in extent,--this rock, I say, is nearly half composed
of microscopic shells. The oolite, also, contains them; and, indeed,
infusorial remains occur in flint and opal; and, as instruments and
observations are perfected, more and more of the solid rocks are found to
have once constituted the framework of animals. It is hardly to be doubted
that such was the fact with nearly all the limestone on the globe,
occupying at least a seventh part of its surface. In fact, we seem fast
coming to regard as sober truth the ancient adage, apparently so
extravagant--_Omnis calx e vermibus; omne ferrum e vermibus; omnis silex e
vermibus._ Indeed, it is the opinion of so competent a geologist as Dr.
Mantell that "probably there is not an atom of the solid materials of the
globe which has not passed through the complex and wonderful laboratory of
life."--_Wond. of Geology_, vol. ii. p. 670.--What a vast field here opens
before us to contemplate the far-reaching plans, the benevolence, and the
wisdom of the Deity!
In the third place, geology shows us that the present system of organic
life on the globe is but one link of a series, extending very far backward
and infinitely forward.
Revelation describes only the existing species, leaving to science the
task and the privilege to lift up the veil that hangs over the past, and
to disclose other economies that have passed away. How many of them have
existed we do not certainly know. If, with Agassiz, we characterize them
by their predominant tribes, we might say that all the period previous to
the new red sandstone constituted the reign of fishes; from thence to the
chalk, the reign of reptiles; from thence to the drift, the reign of
mammifera. But this is a less philosophical view than that of Deshayes,
who finds five great groups of animals, specifically independent of one
another. But who will attempt to fix the chronological limits of these
systems? We can only say that they must have been exceedingly long, if we
can place any dependence upon existing analogies; and we know that each
one of them is made up of numerous subdivisions, or minor groups, widely,
though not entirely, different in composition and organic contents. We
know that the more we examine the whole series, the deeper does our
conviction become that its commencement runs back far, very far, into the
depths of past eternity. We know, also, from the joint testimony of
Scripture and geology, that another change is to pass over the world, to
prepare it for inhabitants far more elevated than those now living upon
it, and in possession of perfect holiness and perfect happiness. And it
may be it will experience far greater changes, adapting it for higher and
higher grades of being, through periods of duration to which we can assign
no limits. O, what a vast chain of being is here spread out before the
imagination, reaching immeasurably far into the depths of the eternity
which is past, and into the eternity which is to come! What a field for
the display of God's infinite perfections! What a vista does it open to us
into the vast plans and purposes of Jehovah!
In the fourth place, geology reveals to us a curious series of
improvements in the condition of worlds, as they pass through successive
changes.
If the earth began its existence in the state of vapor, we can hardly
imagine it in that state capable of sustaining any organic natures, formed
upon the general type of those now existing. Nor, when the vapor was
condensed into a molten globe, could such natures inhabit it, till a crust
had formed over its surface, and the heat had been so reduced as not to
decompose animals and plants. Even then, the natures placed upon it must
have been of a peculiar and low type of organization, capable of enduring
the high temperature and catastrophes which would destroy those of more
delicate and complicated organization. But gradually did the temperature
diminish, while aqueous and atmospheric agencies were accumulating a
deeper and a richer soil, so that the next change of inhabitants would
allow natures of a higher organization and a denser population to occupy
the surface. Their remains, buried in the earth, would increase the
quantity of carbonate of lime in a form available for the use of animals
and plants; that is, lime would gradually be eliminated, by plants and
animals, from its more concealed combinations in the crystalline rocks,
and be converted into carbonates, sulphates, and humates. A larger amount
of organic matter would also be converted into humus. Now, limestone soils
are of all others most favorable to vegetation, when there is a sufficient
supply of organic matter. Hence every successive change becomes more and
more adapted for animals and plants, because the lime and the organic
matter in a state favorable for their support have been increasing; and
the present state of the surface is more favorable than any conditions
which have preceded it, and accordingly it is peopled with more perfect
and more numerous organic natures. Can we doubt but that, if another
change passes over the earth, this same great principle of progressive
improvement will be manifested in the renovated world? I am not prepared
to maintain, however, that this future change will be, like the past ones,
an improvement as to soil and climate; for the change, as Scripture
teaches, will be accomplished by fire; and so different will be the state
of existence in the new earth, wherein dwelleth righteousness, that we
cannot say how far the present system of nature will be introduced. But
that it will be an improved condition, we can hardly doubt, if we infer
any thing from the splendid figures by which it is described in the Bible,
and from the character of those who are to be its denizens.
Some of the facts of modern astronomy impress us with the idea that this
principle of progress may extend to other worlds. Some of these are in a
gaseous state, some condensed into fiery liquid globes, some covered with
a crust of solidified volcanic matter, and some surrounded by a liquid,
like water. Do not these facts justify the supposition, that the changes
which our earth has undergone are merely a single example of a great
principle in God's government of the natural world? If so, it presents the
divine wisdom in an interesting aspect. We see the Deity employing the
same matter for different purposes. Instead of creating it for one single
economy of organic beings, he seems to have made it the theatre for the
display of his benevolence through successive periods; but at the same
time not losing sight of the highest use he intended to make of it, by the
introduction of rational and immortal natures upon it. Human wisdom would
have pronounced this impossible; but divine wisdom, prompted by divine
benevolence, could accomplish it.
Finally, geology discloses to us chemical change as a great animating,
controlling, and conservative principle of the material universe.
When Newton brought to light the principle of gravitation, and showed how
it controls and keeps in harmonious movement the heavenly bodies, he
developed the great mechanical power by which the universe is governed.
And this power was supposed for a long time to be superior to all others.
But geology has brought out a second great controlling and conservative
agency,--the chemical power,--"the second right hand of the Creator," as
Dr. McCulloch expressively calls it. Suppose matter under the control of
gravity, and let it be balanced by a centrifugal force. You have, indeed,
harmonious motions among the celestial bodies, and, if no disturbing cause
come in, you have endless motion. But until you introduce chemical
agencies, every thing in the individual worlds would be compacted by
gravity into one dead mass of matter, destined to no resurrection. But let
chemical agencies leaven that mass, let affinity and cohesion commence
their segregating processes, and constant motion and change would follow,
with a thousand new and splendid forms. Especially when the Deity had
infused the living principle into portions of that matter, and put
chemistry, and her handmaid electricity, under the control of the vital
power, would these worlds teem with animation, and countless exhibitions
of beauty.
And in all known worlds, these chemical changes are at work unceasingly.
We know not whether those worlds are all inhabited, but we have evidence
that all are undergoing the transmutations of chemistry; not on their
surface merely, but in their deep interior. The consequence is, universal
change; change often upon a vast scale; change extending through thousands
and millions of years, and through the entire mass of immense worlds. We
have glanced, in these lectures, at the most important of those changes
which this world has undergone, and we have seen it to be almost
universal. We have found that the entire crust of the globe, many miles in
thickness, and probably to its centre, has been dissolved by heat, and
much of it also by water; that a large part of it, at least, has, by the
same chemistry, been made to constitute portions of the animal frame;
that, even now, much of its interior is held in igneous solution, and that
probably the time was when its entire mass was a molten, self-luminous
world. Indeed, the conjecture is not without some foundation, which
carries back this chemical action one step farther, and makes the world
originally a diffused mass of nebula.
At this point of the argument, geology appeals to astronomy, to show how
widely this principle of chemical change has operated, and still operates,
in the universe. We look first at the nebulae; for here we probably find
matter in its most chaotic and attenuated form, constituting
self-luminous, diffused masses of vapor. In some of them, however, that
matter has begun to condense, doubtless by the radiation of its heat. In
the comets, we find probably similar matter, some of it still farther
advanced in the process of condensation, so that perhaps a nearly solid
nucleus may exist. In the sun and fixed stars, the condensation has gone
on so far that cohesive attraction begins to operate, the latent heat of
the vapor is extricated, and melted luminous worlds are the result. Around
them, however, there probably still floats a wide atmosphere of the more
elastic materials, which the heat dissipates, of which the zodiacal light,
perhaps, furnishes us with an example. The nebulosity which surrounds the
asteroids, Ceres, Pallas, Juno, Vesta, and Astrea, renders it probable
that, though they have advanced so far in the process of refrigeration as
to become opaque, they may still retain heat enough to dissipate much of
their substance. Still farther advanced towards the condition of a
habitable world is the moon; and yet volcanic desolation covers its
surface. Not improbably Jupiter is nearly surrounded with a fluid like
water, and Saturn by a fluid lighter than water--being still farther
advanced towards the condition of the earth.
I acknowledge that these are but slight glimpses of the geology and
chemistry of other worlds. And yet, taken in connection with the
geological history of our own globe, do they not furnish us with some
extremely probable examples of those changes to which our earth has been
subject? They show us that worlds may exist in the form of vapor, and that
some are actually at this time in the various conditions through which
geology supposes this world to have passed. Do we not, in these examples,
gather strong intimations of a great law of chemical change in the
universe? Gaseous matter, so far as we know, appears to have been the
earliest state of the universe; and then, by the agency of heat, it passes
through the successive changes of liquid and solid, which have been
described.
The chemical changes that take place on the earth, under our immediate
cognizance, through the agency of water, usually proceed, under favorable
circumstances, in a cycle; that is, the substance, after passing through a
series of changes, returns at length into the same condition from which it
started. Thus aqueous vapor, by the loss of heat, is first converted into
water, next into ice, and then, by the access of heat, into water again,
and at last into vapor. The question naturally arises, whether those
mutations, through which worlds are passing, may not form a similar cycle.
We are able to trace them through several steps, from gaseous to liquid,
and from the liquid to the solid; and we are assured, on the testimony of
Scripture, that the next change of the earth will be from solid to liquid.
And in those stars which in past ages have suddenly broken forth with
remarkable splendor, and then disappeared, may we not have examples of
other worlds burnt up,--not annihilated,--but deluged by fire, and either
dissipated or again cooled? What changes, if any, will succeed the final
conflagration of the globe, neither science nor revelation informs us.
Yet, if the laws of nature respecting heat are not entirely altered, other
changes must follow; and we have seen, in a former lecture, that those
changes are perfectly consistent with our ideas of heaven, and that they
may, in fact, enhance the happiness of heaven. They may go on forever; in
which case, we can hardly doubt but they would form a cycle, though how
wide the circuit we cannot conjecture; or they may, at least, reach an
unchanging state. I confess, however, that the idea of perpetual change
corresponds best with the analogies of the existing universe; and in
eternity, as well as in time, it may form an essential element of
happiness.
In this world, too, this unceasing change, though it presents at first
view a strong tendency to ruin, is, in fact, the grand conservative
principle of material things. In a world of life and motion like ours, it
is impossible that bodies, especially organic bodies, should not be
sometimes subject to violent disarrangements and destruction from the
mechanical agencies which exist; and were no chemical changes possible,
ultimate and irremediable ruin must be the result. But the chemical
powers, inherent in matter, soon bring forth new forms of beauty from the
ruins; and, in fact, throughout all nature, the process of renovation
usually counterbalances that of destruction; and thus far, indeed, the
former has done more than this; for every time nature has changed her
dress in past ages, she has put on more lovely robes, and a fresher
countenance. Can we doubt that this same principle of change, operating,
as it does, on a stupendous scale through the universe, is one of the
great means of its preservation? It seems, indeed, paradoxical to say that
instability is the basis of stability. But I see not why it is not
literally true; and I can hardly doubt but this principle is superior to
the laws of gravity--superior to every other law, in fact, for giving
permanence and security to the universe.
It is true that, in the case of man, connected as diminution and decay are
with the curse denounced on sin, they assume, in his view, a melancholy
aspect; and the perishable nature of all created things has ever been
viewed by the sentimentalist with sad emotions.