Narrative of an Expedition to the Sources of the Mississippi

Addenda. — Animals Inclosed in Rock, &c.

Toads.—In 1770, a toad was brought to Mr. Grignon inclosed in two hollow shells of stone; but, on examining it nicely, Mr. G. discovered that the cavity bore the impression of a shell-fish, and, of consequence, he concluded it to be apocryphal.

In 1771, another instance occurred, and was the subject of a curious memoir read by Mr. Guettard to the Royal Academy of Sciences at Paris. It was thus related by that famous naturalist:—

In pulling down a wall, which was known to have existed upwards of a hundred years, a toad was found without the smallest aperture being discoverable by which it could have entered. Upon inspecting the animal, it was apparent that it had been dead but a very little time; and in this state it was presented to the Academy, which induced Mr. Guettard to make repeated inquiries into the subject, the particulars of which will be read with pleasure in the excellent memoir we have just cited.

Worms.—Two living worms were found, in Spain, in the middle of a block of marble which a sculptor was carving into a lion, of the natural color, for the royal family. These worms occupied two small cavities to which there was no inlet that could possibly admit the air. They subsisted, probably, on the substance of the marble, as they were the same color. This fact is verified by Captain Ulloa, a famous Spaniard, who accompanied the French academicians in their voyage to Peru to ascertain the figure of the earth. He asserts that he saw these two worms.

Adder.—We read in the Affiches de Provence, 17 June, 1772, that an adder was found alive in the centre of a block of marble thirty feet in diameter. It was folded nine times round, in a spiral line. It was incapable of supporting the air, and died a few minutes after. Upon examining the stone, not the smallest trace was to be found by which it could have glided in or received air.

Crawfish.—Misson, in his Travels through Italy, mentions a crawfish that was found alive in the middle of a marble in the environs of Tivoli.

Frogs.—M. Peyssonel, king’s physician at Guadaloupe, having ordered a pit to be dug in the back part of his house, live frogs were found by the workmen in beds of petrifaction. M. P., suspecting some deceit, descended into the pit, dug the bed of the rock and petrifactions, and drew out himself green frogs, which were alive, and perfectly similar to what we see every day.

We are informed by the European Magazine, February 21, 1771, that M. Herissan inclosed three live toads in so many cases of plaster, and shut them up in a deal box, which he also covered with thick plaster. On the 6th of April, 1774, having taken away the plaster, he opened the box, and found the cases whole and two of the toads alive. The one that died was larger than the others, and had been more compressed in its case. A careful examination of this experiment convinced those who had witnessed it, that the animals were so inclosed that they could have no possible communication with the external air, and that they must have existed during this lapse of time without the smallest nourishment.

The Academy prevailed upon M. Herissan to repeat the experiment. He inclosed again the two surviving toads, and placed the box in the hands of the Secretary, that the Society might open it whenever they should think proper. But this celebrated naturalist was too strongly interested in the subject to rest satisfied with a single experiment; he made, therefore, the two following:—

1. He placed, 15 April, 1771, two live toads in a basin of plaster, which he covered with a glass case that he might observe them frequently. On the 9th of the following month, he presented the apparatus to the Academy. One of the toads was still living; the other had died the preceding night.

2. The same day, April 15, he inclosed another toad in a glass bottle, which he buried in sand, that it might have no communication with the external air. This animal, which he presented to the Academy at the same time, was perfectly well, and even croaked whenever the bottle was shook in which he was confined. It is to be lamented that the death of M. Herissan put a stop to these experiments.

We beg leave to observe upon this subject, that the power which these animals appear to possess of supporting abstinence for so long a time, may depend upon a very slow digestion, and, perhaps, from the singular nourishment which they derive from themselves. M. Grignon observes that this animal sheds its skin several times in the course of a year, and that it always swallows it. He has known, he says, a large toad shed its skin six times in one winter. In short, those which, from the facts we have related, may be supposed to have existed many centuries without nourishment, have been in a total inaction, in a suspension of life, or a temperature that has admitted of no dissolution; so that it was not necessary to repair any loss, the humidity of the surrounding matter preserving that of the animal, who wanted only the component parts not to be dried up, to preserve it from destruction.

The results of modern chemistry and philosophy have proved the number of elementary substances to be far greater than was admitted in the preceding century. And this discovery is progressive, and will probably go on a long time; after which, it is not improbable a new race of chemical and philosophical observers will spring up, who will be able to decompose many substances we now consider elementary, and thus again reduce the number of elements of which all external matter is composed. It would not be wonderful if posterity should reduce the number of elements even as low as the ancients had them. Such a result would throw new light on the mysterious and intricate connection which seems to exist between animal, vegetable, and mineral matter. We should then, perhaps, have less cause to wonder that toads, &c., are capable of supporting life in stone, that birds should exist in solid blocks of wood, &c.

But toads are not the only animals which are capable of living for a considerable length of time without nourishment and communication with the external air. The instances of the oysters and dactyles, mentioned at the beginning of this article, may be advanced as a proof of it. But there are other examples.—European Magazine, March, 1791.

A beetle, of the species called capricorn, was found in a piece of wood in the hold of a ship at Plymouth. The wood had no external mark of any aperture.—European Magazine.

A bug eat itself out of a cherry table at Williamstown, Mass. See an account of this phenomenon, by Professor Dewey, in the Lit. and Philos. Repertory.

These phenomena remind us of others of a similar nature and equally certain.

In a trunk of an elm, about the size of a man’s body, three or four feet above the root, and precisely in the centre, was found, in 1719, a live toad, of a moderate size, thin, and which occupied but a very small space. As soon as the wood was cut, it came out and slipped away very alertly. No tree could be more sound. No place could be discovered through which it was possible for the animal to have penetrated, which led the recorder of the fact to suppose that the spawn from which it originated must, from some unaccountable accident, have been in the tree from the very moment of its first vegetation. The toad had lived in the tree without air, and, what is still more surprising, had subsisted on the substance of the wood, and had grown in proportion as the tree had grown. This fact was attested by M. Hebert, Ancient Professor of Philosophy at Caen.

In 1731, M. Leigne wrote to the Academy of Sciences at Paris an account of a phenomenon exactly similar to the preceding one, except that the tree was larger, and was an oak instead of an elm, which makes the instance the more surprising. From the size of the oak, M. Leigne judged that the toad must have existed in it without air or any external nourishment, for the space of eighty or a hundred years.

We shall cite a third instance, related in a letter the 5th Feb. 1780, written from the neighborhood of Saint Mexent, of which the following is a copy.

“A few days ago, I ordered an oak tree of a tolerable size to be cut down, and converted into a beam that was wanting for a building I was then constructing. Having separated the head from the trunk, three men were employed in squaring it to the proper size. About four inches were to be cut away on each side. I was present during the transaction. Conceive what was their astonishment when I saw them throw aside their tools, start back from the tree, and fix their eyes on the same point with a kind of amazement and terror. I instantly approached, and looked at that part of the tree which had fixed their attention. My surprise equalled theirs, on seeing a toad, about the size of a large pullet’s egg, incrusted, in a manner, in the tree, at the distance of four inches from the diameter and fifteen from the root. It was cut and mangled by the axe, but still moved. I drew it with difficulty from its abode, or rather prison, which it filled so completely that it seemed to have been compressed. I placed it on the grass; it appeared old, thin, languishing, decrepit. We afterwards examined the tree with the nicest care, to discover how it had glided in; but the tree was perfectly whole and sound.”—European Magazine.

Bat.—A woodman engaged in splitting timber for rail-posts in the woods close by the lake in Haming (a seat of Mr. Pringle’s in Selkirkshire), lately discovered, in the centre of a large wild cherry tree, a living bat, of a bright scarlet color, which he foolishly suffered to escape, from fear, being fully persuaded it was (with the characteristic superstition of the inhabitants of that part of the country) a “being not of this world.” The tree presented a small cavity in the centre, where the bat was inclosed, but is perfectly sound and solid on each side.—N. Y. Lit. Journ. and Belles-Lettres Repository, taken from the London Semi-Monthly Magazine.

Skull in Wood.—A tenant of the Rev. J. Cattle, of Warwick, lately presented to him a part of the solid butt of an oak tree, containing within it the skull of some animal (unknown). It was in the part of the tree nine feet above the ground, and was perfectly inclosed in solid timber.—N. Y. Lit. Journ. and Belles-Lettres Repository, from European Magazine.

X

A Memoir on the Geological Position of a Fossil-Tree in the Series of the Secondary Rocks of the Illinois.

The spirit of inquiry which has been excited in this country in regard to objects of natural history, while it has enlarged the boundaries of our knowledge of existing species, has directed some of its more valuable researches to those organized forms which have perished and become embalmed in the shape of petrifactions, in the body of solid rocks. A petrified tree of this kind has recently been discovered in the secondary250 rocks at the source of the Illinois River. Having recently visited this evidence of former changes in the flora of the West, I embrace the occasion, while my recollections are fresh, to give an account of it.

The tract of country separating the southern shores of Lake Michigan from the Illinois River, is a plat of table-land composed of compact limestone, based on floetz or horizontal sandstone. This formation embraces the contiguous parts of Illinois, and spreads through Indiana, Ohio, and the Peninsula of Michigan. It is overspread with a deposit of the drift era, covered with a stratum of alluvial soil, presenting a pleasing surface of prairies, forests, and streams. These features may be considered as peculiarly characteristic of the junction of the Rivers Kankakee and Des Plaines, which constitute the Illinois River. This junction is effected about forty miles south of Chicago.

The fossil in question occurs about forty rods above the junction of the Kankakee. The sandstone embracing it is deposited in perfectly horizontal layers, of a gray color and close grain. It lies in the bed of the Des Plaines. The action of this stream has laid bare the trunk of the tree to the extent of fifty-one feet six inches. The part at the point where it is overlaid in the western bank is two feet six inches in diameter. Its mineralization is complete. The trunk is simple, straight, scabrous, without branches, and has the usual taper observed in the living specimen. It lies nearly at right angles to the course of the river, pointing towards the southeast, and extends about half the width of the stream. Notwithstanding the continual abrasion to which it is exposed by the volume of passing water, it has suffered little apparent diminution, and is still firmly imbedded in the rock, with the exception of two or three places where portions of it have been disengaged and carried away; but no portion of what remains is elevated more than a few inches above the surface of the rock. It is owing, however, to those partial disturbances that we are enabled to perceive the columnar form of the trunk, its cortical layers, the bark by which it is enveloped, and the peculiar cross fracture, which unite to render the evidence of its ligneous origin so striking and complete. From these characters and appearances, little doubt can remain that it is referable to the species juglans nigra, a tree very common to the forest of the Illinois, as well as to most other parts of the immense region drained by the waters of the Mississippi. The woody structure is most obvious in the outer rind of the trunk, extending to a depth of two or three inches, and these appearances become less evident as we approximate the heart. Indeed, the traces of organic structure in its interior, particularly when viewed in the hand specimen, are almost totally obliterated and exchanged, the vegetable matter being replaced by a mixed substance, analogous, in its external character, to some of the silicated and impure calcareous carbonates of the region. Like those carbonates, it is of a brownish-gray color and compact texture, effervesces slightly in the nitric and muriatic acids, yields a white streak under the knife, and presents solitary points, or facets, of crystals resembling calc spar. All parts of the tree are penetrated by pyrites of iron of a brass yellow color, disseminated through the most solid and stony parts of the interior, filling interstices in the outer rind, or investing its capillary pores. There are also the appearances of rents or seams between the fibres of the wood, caused by its own shrinkage, which are now filled with a carbonate of lime, of a white color and crystallized.

From an effect analogous to carbonization, the exterior rind and bark of the tree have acquired a blackish-hue, while the inclosing rock is of a light-gray color, characters which are calculated to arrest attention.

There is reason to conclude that the subject under consideration is the joint result, partly of the infiltration of mineral matter into its pores and crevices, prior to inclosure in the rock, and partly to the chemical action educed by the great catastrophe by which it was translated from its parent forest, and suddenly enveloped in a bed of solidifying sand.

At the time of my visit (August 13, 1821), the depth of water upon the floetz rocks forming the bed of the River Des Plaines, would vary from one to two feet; but it was at a season when these higher tributaries, and the Illinois itself, are generally at their lowest stage. Like most of the confluent rivers of the Mississippi and their tributaries, the Des Plaines is subject to great fluctuations, and during its periodical floods may be estimated to carry a depth of eight or ten feet of water to the junction of the Kankakee. At those periods, the water is also rendered turbid by the quantity of alluvial matter it carries down, and a search for this organic fossil must prove unsuccessful. But during the prevalence of the summer droughts, in an atmosphere of little humidity, when the waters are drained to the lowest point of depression, and acquire the greatest degree of transparency, it forms a very conspicuous trait in the geology of the stream, and no person, seeking the spot, can fail to be directed to it.

The sand-rock containing this petrifaction is found in a horizontal position, differing only with respect to hardness and color. The remains of fossil organized bodies in this stratum are not abundant, or have not been successfully sought. It is probable that future observations will prove that its organic conservata are chiefly referable to the vegetable kingdom. It is certain, that this inference is justified by the facts which are before me, and particularly by the characteristic appearances of the strata in the bed of the River Des Plaines, where the imbedded walnut is the representative of the ancient flora. At a short distance above, where the bed of the Des Plaines approaches nearer the summit level, limestone ensues, and continues from that point northward to the shores of Lake Michigan. In the vicinity of Chicago, where this limestone is quarried for economical purposes, it is characterized by the fossil remains of molluscous species.

Lake Erie lies at an elevation of five hundred and sixty-five feet above the Atlantic.251

There exists a water communication between the head of Lake Michigan, at Chicago, and the River Des Plaines, during the periodical rises of the latter, but its summer level is about seven feet lower, at the termination of the Chicago portage, than the surface of the lake. From this point to its junction with the Kankakee, a computed distance of fifty miles, the bed of the Des Plaines may be considered as having a mean southern depression of ten inches per mile, so that the floetz rocks at its mouth, lying on a level of forty-eight feet eight inches below the surface of Lake Michigan, have an altitude which cannot vary far from five hundred and fifty feet above the Atlantic. There are no mountains for a vast distance either east or west of this stream. It is a country of plains, in which are occasionally to be seen alluvial hills of moderate elevation; but the most striking inequalities of surface proceed from the streams which have worn their deep-seated channels through it; and an oceanic overflow capable of covering the country, and producing these strata by deposition, would also submerge all the immense tracts of secondary and alluvial country between the Alleghany and the Rocky Mountains, converting into an arm of the sea the great valley of the Mississippi, from the Gulf of Mexico north to the Canadian Lakes. We find in the alluvial soil along the Illinois and Des Plaines blocks of granite, hornblende, and gneiss, of the drift stratum, exhibiting the same appearances of attrition, and of having been transported from their parent beds, which characterize the secondary tablelands along the margin of the great American lakes, the prairies of Illinois, and the western parts of New York.

There is nothing, perhaps, in the progress of modern science, which has tended to facilitate geological research so much as the study and investigation of fossil organic remains. They teach, with unerring lights, how extensively the ancient flora and fauna of this continent have been prostrated, leaving their exact impressions, in all their minuteness, in the newly-formed stratifications. That these impressions, fresh and vivid as we find them, should mark the eras of depositions and crystallization of rocks from the suspension of their elements in water, is the observation of Werner, and it is to him we owe the elements of the Neptunian hypothesis. His general recognition of the epochs of the primitive, transition, and secondary rocks, appears too probable not to commend itself to adoption with regard to all strata which can be conceived to be the products of watery menstrua.

But it remained for Werner, who was the first to perceive an order in strata, also to point out the important application of fossil organic bodies in elucidating their eras, and the natural order of their superposition.

To adopt the words of Dr. Thomas Cooper:—

“There appears to be a series of strata, or, as Werner calls them, formations, that may be considered as surrounding the nucleus of the earth. The first formed, or lowest series, always preserve the same situation to each other, except where occasional eruptions, or circumstances not of a general nature, make a variety in their situations. These strata are not only the deepest, but they are also the highest that are observable in the crust of the earth; forming the tops of the highest mountains. They are characterized by an appearance of crystallization, and by containing no remains of organic matter, animal or vegetable. The strata or formations that in general constitute this first, deepest, highest, and crystallized series, are granite, gneiss, mica-slate, clay-slate, primitive greenstone, granular limestone, serpentine, porphyry, and sienite. These formations are so generally found, and in the same situations as incumbent upon or subtending each other relatively, that they may be considered as universal. Their crystallized appearance shows that their particles have either been dissolved or very finely suspended in water, so that the attraction of crystallization has been free to operate; that this water has been deep, so that the lowermost parts of it have not been much agitated during the crystallization, which would otherwise have been more confused than it is; and, indeed, the oldest formations are the best crystallized. A part of the water covering the nucleus must have been taken up, as water of crystallization, in the primitive formations. When these were deposited, there were no vegetables formed; of course, no animals; nay, even the sea was unpeopled, for there is no trace of any organic remains in these strata. Even the belemnites, the asteriæ, the echini, the entrochi, the most simple forms of oceanic animal life, do not occur until the transition strata appear. Hence the propriety of denominating these formations primitive.

“By processes of nature, besides the consumption of water by the new crystallized masses, to us unknown, the waters appear to have diminished. The highest parts of the primitive formations became the shores to the water superincumbent on their bases and middle regions; the simplest forms of oceanic animals came into existence; the mosses and lichens of high latitude would generally occupy the surface of the primitive strata, gradually decomposed by the alternate action of air and water after many ages. During this period, while the strata were in a state of transition from the chaotic to the habitable state, other deposits would gradually be made from the waters, now decreased in quantity, and take their place below the summits of the primitive range. Those summits being exposed to the action of the atmosphere, of rains, of frost probably, and to the action also of the waters with their contents still incumbent on the earliest strata, would furnish masses and particles washed away, which would mingle with the deposits of the transition series. This series, therefore, will exhibit appearances of mechanical and chemical intermixture of earths and stones, such as are found in the silicious porphyries, the graywackes, the silicious and argillaceous hornblende rocks, the elder red sandstone, &c. During the period when these transition formations were deposited, there would be no land animals, for there would be no vegetables for them to feed upon. There would be no vegetables unless some few lichens, mosses, or ericas, that would find foothold upon the slight decomposition that, after the lapse of some ages, would take place on the surface of the primitive rocks. The sea only would be peopled, and that but sparingly; for, in that mass of muddy water, none but the lowest and most inferior grades of animal life, and such as do not inhabit deep water, could exist. Hence, we find the transition formations contain in their substances some belemnites, asteriæ, entrochi, echini, &c., but no organized vegetable substance except, very rarely, in the latest rocks of this series, and no remains whatever of terrestrial animals. Indeed, in the high latitudes of the outgoings or summits of the primitive strata, very few vegetables, even at the present day, can live. No vegetation fit for animal life could take place until the transition, and most of the next series of secondary or floetz formations had subsided. These would occupy lower and lower situations, till a rich soil, from every kind of intermixture of earth mechanically deposited, would afford a proper temperature of region, and an easily decomposed soil, wherein vegetables could grow.

“Next to the transition series, come the secondary, or, as the German mineralogists call them, the floetz rocks; so called, because they appear to be more floated or horizontal, though I confess the appellation does not appear to me peculiarly appropriate. These strata consist principally of sandstone, limestone—sometimes fetid from bituminous impregnations, sometimes shelly—secondary greenstone, graphite, coal, gypsum, rock salt. I have observed that the Alpine heights of the primitive mountains could at no time furnish much food. The same remark, but in a less degree, will apply to the transition range; the low and kindly climates occupied by the secondary series. The soft and decomposable nature of these depositions would furnish the true theatre of vegetable life, and, until these regions were filled with vegetables, the race of animals could not have been produced; for on what could they subsist? Graminivorous animals, therefore, must have succeeded the various forms of vegetable existence; and carnivorous, the graminivorous. The vegetable matter imbedded in the substance of the secondary strata will consist of the remains of vegetables that grow in the transition strata; and the animal remains will consist chiefly of such animals as were produced in the early stages of animal existence, particularly the smaller aquatic animals; and, of these, chiefly shell-fish, as shells are not so soon decomposed as mere animal substance.”

It is to the latter class of depositions—to the secondary series—that we must refer the sandstone of the River Des Plaines, in which we find a walnut, of mature growth, enveloped by, and imbedded in the rock, in the most complete state of mineralization; and, since all geological writers who subscribe to the Neptunian theory are constrained to employ the agency of oceanic depositions of different eras, in explaining the structure of the earth’s surface, it is one of the most obvious and important conclusions, to be drawn from the fact that such submersions and depositions of rock matter have taken place subsequent to the existence of forests of mature growth, and that the rock strata and beds composing the exterior of the earth are the result of different geological epochs, and of successive subsidences of chaotic matter—positions which have been so severely attacked and so often denied, particularly by the disciples of the Huttonian school, that it is not without a feeling of lively interest, I communicate a discovery which appears so conclusive on the subject.

Considerations arising from the frontier position of the country, and the infrequency of the communication, have also induced me to draw from incidental sources, a corroboration of the facts advanced.

In a letter to Governor Cass, of Michigan, dated September 17, 1821, I made the following observations on the subject under review:—

“I consider the petrified tree discovered during our recent journey up the Illinois, so extraordinary an object in the natural history of the country, and calculated to lead to conclusions so important to the science of geology, that I am anxious to avail myself of your concurrent testimony as to the fact of the existence of the tree in a mineralized state, and the natural appearances of the spot where it lies imbedded. I feel the more solicitude on this subject, as I am aware that any description of this phenomenon which I may be induced to communicate to the public, will be received with a degree of caution and scrutiny which it is the province of the naturalist to exercise whenever any discovery is announced affecting the existing theories of the natural sciences, or tending to increase the volume of facts upon which their advancement and perfection depend. I am aware, also, that whatever degree of caution and vigilance it may be proper to exercise to prevent errors from mingling with the sound doctrines of the physical and other sciences, still more care and circumspection is requisite in examining facts which affect the progress of geology.”

I quote an extract from Governor Cass’s reply on the subject:—

“The appearance of the wood and bark indicates that it was a black walnut, the juglans nigra of our forests. We computed its original diameter, at the place where it is concealed in the earth, to have been three feet, and at the other end eighteen inches. The texture of the wood, and the bark and knots, are nearly as distinct as in the living subject, and the process of decay had not commenced previous to the commencement of this wonderful conversion. Every part of the mass which we could examine is solid stone, and readily yields fire by the collision with steel.

“When we visited the spot, the water of the river was at the lowest stage; but there was no part of the tree within some inches of the surface. The rocky bed of the stream was formed round and upon it. We raised from it pieces of the rock, which were evidently in situ, and which had been formed upon the tree posterior to the period of its deposit in its present situation. This rock is a species of sandstone, whose characteristic features must be well known to you.

“There are no mineralized substances of vegetable origin in the vicinity of this specimen, nor are there any appearances which indicate that its present condition has been caused by any peculiar property in the waters of the Des Plaines.”

ADDENDA.

The publication of the foregoing memoir led to several letters being addressed to the author on topics connected with it. Some of these were from gentlemen eminent in science or politics, whose opinions are entitled to the highest respect. Extracts are given from such only as introduce new data, either of fact or opinion.

Geological Theories.—Professor Dewey, of Williams College, observes: “A friend has just lent me your ‘Memoir on a Fossil-Tree.’ Though the account is very interesting, I do not perceive its exact bearing on the Neptunian and Plutonian hypotheses. The fault is doubtless in me, and you will excuse my remarks and set me right. I had supposed the Huttonians and Wernerians did not dispute about the manner in which the secondary rocks were formed. Macculloch, and others before him, led me into this opinion, though it may be erroneous. But Bakewell, who is referred to as authority in Rees’s Cyclopædia, says, p. 131: ‘Geologists are agreed that secondary rocks have been formed by the agency of water.’ If this be so, they would agree generally with the account of Dr. Cooper respecting the formation of petrifactions, and especially those of vegetables, and the fossil-tree would be treated of in a similar manner by both.”

Hutton’s original hypothesis, and not the modifications of it introduced by the Neptu-Vulcanists, were adverted to in reply. Subsequently, Professor Dewey writes:—

“I was greatly obliged by your letter in various respects, and I write you now to make my acknowledgments for it, as well as to maintain the correctness of your notions on the Huttonian hypothesis. As you had seen a Scotch mineralogist directly from the mint of Playfair, I had every reason to suppose you had received correct views of Playfair’s notions on the subject. I have been led, therefore, to examine the matter, and, as I may have set you on the search, I wish to prevent your continuing it on my account, or from what I wrote.

“Playfair’s Illustrations I have never seen. Occasional extracts, or allusions to its points, have fallen in my way. But I have before me a very full abstract of Hutton’s paper on the subject, from the Transactions of the Royal Society of Edinburgh. It is from the very paper in which he announces his hypothesis. In that paper he mentions that the consolidation of all the hard crust of the globe has been effected by heat and fusion, extending it to secondary as well as primitive rocks, and mentioning particularly Spanish marble, shell limestone, oolite, and chalk.

“This operation of heat, he says, is exemplified by chalk, which is to be found in all gradations, from marble to loose chalk. This is his precise notion, but not his words. I had once looked at this paper before, and thought much of this theory; but this thought had been obliterated from my mind by thoughts advanced by others, as I thought in consistency with the sentence I quoted from Bakewell. At least, one objection to Hutton’s views would be removed by modifying his theory in the manner it seems to be by Bakewell. Though Hutton does not think this to be necessary; for he appears to feel no difficulty in accounting for petrifactions of wood on his hypothesis, for he mentions that we have many proofs of the penetration of flinty matter, in a state of fusion, in other bodies, such as insulated pieces of flint in chalk or sand, and fossil wood penetrated with silicious matter.

“Still, the grand reasons of Hutton for employing heat as the agent of consolidation are opposed to the above modification of his theory. These reasons, as you know, are the insolubility of most mineral substances in water, and the disappearance of the water from the cavities of minerals which have been consolidated. The first is, indeed, the great one for Hutton; for the crystallization of salts in water, and the existence of liquids, in some cases, in the cavities of the most solid minerals, show well enough that the water might or might not disappear, as the circumstances were different.

“If the Huttonians maintain, as he did, the formation of petrifactions by heat, which consistency requires, I concede, indeed, to you that that fossil-tree stands as a grand monument of some different process; and yet, we can hardly suppose that they do not see great difficulty in the common notion on the subject. The rapidity with which the petrifactions must have taken place—a point well illustrated in Hayden’s Geological Essays—seems to require some new notions on the subject. What these may be, I cannot tell; but I believe that neither of these two hypotheses will be adopted exclusively, half a century hence, on this point, or on geology generally. I think, with you, that our countrymen need illumination on the subject of Hutton’s hypothesis, and I wish some one would attempt it.”

Trap-Rocks of Europe and America.—“I suspect the greenstone of our country, when examined as it ought to be, will be found, in its geological relations, much to resemble the basalt of Europe; and that the same difficulties will attend it, on Werner’s hypothesis, as now attend the basalt. Indeed, I know not how we can account for what Bakewell and Macculloch state on this hypothesis.”

Sandstone of Virginia.—“I have seen a piece of a petrified tree, about eight inches through, found in the sandstone of Virginia, but could get none of it. The petrifaction was far finer than the stone in which it lay, and was, like it, silex.”

Sandstone of Ohio.—C. Atwater, Esq., in a letter to the author, observes:—

“I can assure you that the finding of whole trees in sandstone is nothing strange in this State. Some of these trees are imbedded in sandstone one hundred feet below the surface. Zanesville and Gallipolis are the best spots to find these fossils.

“There is no part of the tree but what I have in my cabinet, not excepting their leaves, fruit, and even fungi attached to them.”

Mosaical History of the Creation.—B. Irvine, Esq., in adverting to remarks on the Illinois fossil, observes:—

“They may yet awaken some ideas in the minds of the people on the wonders of physics—and I had almost said, the slow miracles of creation; for, if ever there was a time when matter existed not, it is pretty evident that millions of years, instead of six days, were necessary to establish order in chaos, let Cuvier, &c. temporize as they may. However, it is the humble allotment of the herd to believe or stare; it is the glory of intelligent men to inquire and admire.”

The doctrine of materialism, adverted to by Mr. Irvine, it is the province of divines to controvert. One remark may be predicted on the biblical era of the six days. It is now believed to be generally conceded by eminent geologists and ecclesiastics, that the term “day,” employed by the translators of the English version of the Scriptures, is used in Gen. ch. i. in a sense synonymous with “era” or “time,” as it is emphatically used in Gen. ch. ii. ver. 4. For an able exposition of the present views on this subject, see the American Journal of Science, vol. XXV. No. 1.