Part 37

To give any correct idea of the boundless field which that instrument has opened into the infinitesimal parts of creation, it would be necessary to go into details too extended for the present occasion. Perhaps the animalcula or infusoria furnish the best example. "In the clearest waters," says an able writer, "and also in the strongly-troubled acid and salt fluids of the various zones of the earth; in springs, rivers, lakes, and seas; in the internal moisture of living plants and animal bodies; and probably, at times, carried about in the vapor and dust of the whole atmosphere of the earth, exists a world, by the common senses of mankind unperceived, of very minute living beings, which have been called, for the last seventy years, _infusoria_. In the ordinary pursuits of life, this mysterious and infinite kingdom of living creatures is passed by without our knowledge of, or interest in, its wonders. But to the quiet observer how astonishing do these become, when he brings to his aid those optical powers by which his faculty of vision is so much strengthened! In every drop of dirty, stagnant water, we are generally, if not always, able to perceive, by means of the microscope, moving bodies, of from one eleven hundred and fiftieth to one twenty-five thousandth of an inch in diameter, and which often lie packed so closely together that the space between each individual scarcely equals that of their diameter."--Prichard, _History of Infusoria_, p. 2, 1841.

Again says he, "It is hardly conceivable that, within the narrow space, [of a grain of mustard-seed,] eight millions of living, active creatures can exist, all richly endowed with the organs and faculties of animal life. Such, however, is the astonishing fact."--_Ib._ p. 3.

In short, whoever will thoroughly study this subject will be satisfied that Dr. Ehrenberg does not exceed the truth when he asserts, as the result of his inquiries, that "experience shows an unfathomableness of organic creations, when attention is directed to the smallest space, as it does of stars, when revealing the most immense."--_Prichard_, p. 8.

He who follows out the revelations of the telescope, as it penetrates deeper and deeper into space, will feel, when he has seen the remotest object which its power discloses, that there must certainly be a vast unknown region beyond, infinitely exceeding that one over which he has passed. Just so is it with the microscope. It penetrates to an astonishing distance into the infinitesimal forms of organic and inorganic matter; but every improvement in the instrument reaches a new and equally interesting field; and the conclusion forces itself upon the mind that there are regions beyond of indefinite extent, teeming with countless millions even of organic beings, of a size much more diminutive than those yet discovered, and with inorganic forms too minute for the imagination to conceive. Indeed, we can no more set limits to creation in the direction pointed out by the microscope than in that laid open by the telescope. We hence get a most impressive conception of divine wisdom and benevolence, which could thus bestow exquisite organization and life upon atoms minute beyond the power of the imagination to conceive. Indeed, it seems to me that the lesson is even more striking than the contemplation of vast worlds in rapid and harmonious motion; because the latter seem to demand only infinite power, but the former requires infinite wisdom to direct infinite power.

_In the seventh and last place, geology has given great enlargement to our knowledge of the divine plans and operations in the universe, and in the following particulars_:--

1. It expands our ideas of the time in which the material universe has been in existence as much as astronomy does in regard to its extent.

To those not familiar with the details of geology, this will probably seem 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.