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tle Rock, I observed an approaching change in the timber, the pine having entirely disappeared, and being replaced by deciduous trees.

the truncated beds of the rock, standing at an elevation of 75°, and in some places they were vertical. From the summit of this mound there is a surprisingly beautiful view of the surrounding country; wherever the siliceous Where this change commenced, I found a total change ridges are, pine timber exclusively prevails, and where the of mineral structure; the old red sandstone had given river inundates the low lands, there the deciduous trees place to an ancient greenstone, containing great quantities betray the inroads it makes. Immense quantities of rich of crystallized hornblende. The rocks rose here about one land will be here reclaimed when the system of making hundred and fifty feet, and having reached the top, I saw levées is introduced. I also visited some isolated high- I was upon the brim of what-in the western part of Virlands on the opposite side of the river; one named Crys-ginia, near the Clinch mountain, where I have seen sevtal hill had been pointed out as interesting to a mineralogist, and some persons at various periods had pretended to work there upon a silver mine. Crystal hill is a mere outlier of old red sandstone, much inclined, and based upon grauwacke shale and slate. The slate near the river is occasionally very much diversified by strong ferruginous bands, and at very low water shows a good deal of sulphuret of iron. These minerals present appearances which have deceived some sanguine persons, some of whom I met with, urgently desirous of being correctly informed on this subject. After I had completed my examinations of the Territory, and arrived at Little Rock on my return, I thought it a point of duty to warn them against wasting their means in a pursuit, of the probable advantages of which they were not competent judges, and respecting the prosecution of which they were unable to determine where they ought to begin, and where they ought to desist; and I stated to them, what I here repeat, that I had never seen, in any portion of the Territory of Arkansas, the least indication of the precious metals, apart from a very small portion of silver contained in the sulphuret of lead. Nor, indeed, did I ever find in the transition rocks of this part of the country any fossil except a new species of petremite in the old red sandstone near the Mammelle.

eral, as well as in the neighborhood of Sequatchee valley, in Tennessee-is called a cove: this cove, which is not quite circular, but rather affecting the form of a gourd, has an anterior basin, which slopes pleasingly down, and contains, probably, one thousand five hundred acres of very excellent soil. In various parts of the bottom, I found large masses of decomposing felspar, studded with black tourmalines, some of which were in long prisms, whilst others formed a stellated figure of beautifully delicate acicular rays. Some of the felspathic rocks were filled with amorphous masses of white sulphuret of iron, believed by many persons to be silver. In other parts of the cove I found masses of coarse grained syenite, consisting of red felspar, hornblende, mica, and some quartz. But what will always give celebrity to this remarkable locality, now called Magnet cove, is the magnetic iron which abounds there. There is an extensive mound of it covered with pebbles of magnetic iron, from an ounce to four pounds weight. From some examinations I made by digging, I am certain these loose pebbles, like those of the vein of iron in Missouri, overlie masses of the metal of prodigious extent. Some of the specimens I obtained possess a surprising magnetic power; and such is the influence of the inass in place, that Colonel Conway, the surveyor general, informed me he had been unable to survey the country, as the needle will not traverse on approaching this locality. From a careful examination of the different portions of this most interesting cove, I came to the conclusion that the whole structure of this elevation, as far as its exterior as well as its interior slopes were concerned, was an old greenstone belonging to the intrusive rocks, and occupy

stone; that, as far as the greenstone extends, all the trees are deciduous, and without its limit all the trees are evergreens and pines. It is impossible to look at this quasi-circular brim, and the cove below, and take into consideration, at the same time, all the minerals and metals found there, without being impressed with the opinion that it is the result of a very remote volcanic action, and is, perhaps, one of those extremely ancient craters that may have preceded those of which basalt and lava are the products.

Having made such examinations in the neighborhood of Little Rock as my opportunities admitted of, I directed my course west, towards the hot springs of Washita. On leaving the town, I soon got once more upon the old red sandstone, reposing on the grauwacke, and indeed never left it, with one exccption, until I drew nigh to the Little Missouri river, south of 34° north latitude. I crossed a small stream, called the Fourche, which runs into the Ar-ing, for a limited space, a place amidst the old red sandkansas, and the heads of other streams said to run into bayou Bartholomew, though I cannot vouch for the accuracy of this last fact, which I had from report. This is a stream that will be of importance hereafter to the settlers in that part of Arkansas, as it is very long, may easily be made navigable, and passes through the fertile county of Chicot, whence it disembogues finally into the Washita river, in the State of Louisiana. Where I crossed these streams and I add the Saline river, another important trbutary of the Washita, which I crossed twenty-eight miles from Little Rock-I invariably found, upon a minute investigation of their beds, the same tertiary deposite of marine shells which I had seen at Little Rock. In the bed of the Safine, I found, at a depth of not more than a foot under the surface, a regular calcareous rock, enclosing immense quantities of oyster shells, the rocky part being evidently formed from the broken down exuvia of marine animals, disintegrated in long periods of time. The settlers in the neighborhood, whose chimneys were built of mud, which had to be replaced annually, were extremely well pleased with the discovery of a mineral so useful to them for domestic purposes. At thirty-five miles from Little Rock, the country is covered with ferruginous conglomerate of the old red sandstone. Wherever this latter rock is found, the pine prevails, as is usually the case in siliceous countries; but, about forty-eight miles from Lit

Of the Eocene period of Mr. Lyell."

These deposites evidently belong to the period when the ancient littoral shore was washed by the ocean. Pinus Australis, Mich.

VOL. XIV.--A 43

The distance from Magnet cove to the Hot Springs of the Washita is about sixteen miles, keeping always upon the old red sandstone, and no change in the mineral, except one vein of greenstone, with small plates of brown mica, which crops out at about half the distance. At length, nearing a considerable ridge, and turning into a small valley about fifty yards broad, I saw, from the appearance of things, that I had reached the Hot Springs of the Washita, so great an object of curiosity to men of science, and so little known to the rest of the world.

At

This valley, which runs about north and south, and divides two lofty ridges of old red sandstone, extends about eight hundred yards, and then deflects to the west. the foot of the eastern ridge, which is about five hundred feet high, flows a lively stream, which rises in the hills to the northeast: this ridge has, towards the top, a dense growth of pine and oak trees, amongst which are strewed fragments of the rock, often very ferruginous, and pieces of a strong band of ironstone, which traverses the ridge in the direction of N. N. E. and S. S. W., and dipping S.

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E. with the sandstone, at an angle of about 45°. There is also some conglomerate on this hill, held together by ferruginous cement. The stream, for a considerable distance, runs upon the grauwacke slate, upon which the sandstone rests. I had entered the valley but a short distance before I saw, on the flank of the east ridge, a rock of a totally different character from that constituting the ridge, impending, like a curtain, down to the stream, and I at once recognised it for a tavertin deposited by the mineral waters. The curtain, with some intervals, extends along the stream for about four hundred yards from the slope of the ridge, presenting sometimes abrupt escarpments of from fifteen to twenty-five feet, and at other times showing itself in points and coves advancing into and receding from the stream. This travertin extends back east from the stream about one hundred and fifty yards, leaning upon the acclivity of the old red sandstone, to where several powerful springs are now situated. Some of the springs rise in the bed of the stream; one very fine spring rises in its west bank, and numerous others, of which perhaps thirty rather copious ones are found at various heights on the ridge, rising through the old red sandstone rock. Of springs of feebler force there are a great many. Sometimes one or more of these are said to disappear, and it is certain that new ones are frequently breaking out. Some of them issue from the rock at an elevation of at least one hundred feet from the valley, where the present log cabins are built, and where a flourishing village will no doubt exist ere long. A more beautiful and singularly convenient situation for a town cannot be imagined; for, by the aid of the simplest frames to support spouts, the hot water may be conveyed to the houses in great profusion, for baths and medical purposes, as well as for domestic uses. Upon repeated trials with my register thermometers, I found the water of some of the principal springs to be 146° of Fahrenheit, and I never found it higher, although I should not doubt that, during very dry weather, when the mineral springs were not attenuated by the atmospheric waters, they would mark a few degrees more. But, during my stay, I always found the water hot enough to make my tea without any further boiling, as well as to wash my clothes. Indeed, in this locality, the hot water is so abundant that I found it often troublesome to procure that which was cold, for the Hot Springs occupying a breadth equal to four hundred yards of the base of the ridge, all the hot water was discharged into the creek, which in many parts was of a temperature just fitted for a warm bath; and what further assists to keep up its temperature, is the great number of hot springs rising through the slate at the bottom of the brook this can be seen at almost a hundred places; and although the water does not scald the hand there, still, upon insinuating my fingers a few inches below the ground at the edge of the stream, I was obliged to retire them instantly, having more than once burnt them in that way. If this stream were turned, it is incredible the quantity of water of a temperature perhaps always equal to 145° Fahrenheit, which might be obtained. During the summer droughts, when the stream is low, no fish are ever seen in it, the water being too hot; but when the season arrives for the cold waters to enter the stream in considerable quantities, then trout, perch, and other fish, are taken in all parts of it. I was told, however, that at other portions of the summer, when the whole volume of the stream was not so much heated, the fish would sometimes come up the brook in those parts where no springs came through the slate, but always swam at a particular depth; when crumbs of bread were dropped into them, they rose to them, but stopped when they reached the stratum of hot water, which, being rarefied, was at the top. Frogs and snakes, when forced into the hot water, or falling in inadvertently, immediately stretch themselves out and die. These mineral hot waters, except one or two of the springs, which are

slight chalybeates, are tasteless, having not the least saline trace. A person totally unacquainted with mineralogy, and not aware of any difference between travertino and old red sandstone, might suppose the mineral structure of all the rocks to be homogeneous, and that the waters, not differing in their taste from ordinary warm water, were without any mineral constituent, as the hot waters of the Washita have been reported to be; but these immense deposites of carbonate of lime attest the contrary. On digging about twenty-five feet above the level of the brook, I went through a foot of the carbonate, with traces of sulphate of lime, and then through a dark red oxide, with reniform masses of nodular iron, with botroidal faces. The sulphate was deposited in layers in acicular form. I then came to masses of ferruginous sandstone belonging to the ridge. These seemed to have been loose, and to have been recemented by the deposites from the water, which had filled up all their interstices. I took out one large mass of iron, the walls of which were, in some places, two and a half inches thick, of rich hematite pre, the inside of the nodule containing gypsum and a deep red oxide. These masses almost led me to suppose that they had been deposited by the springs, and that the iron had thus been aggregated by molecular attraction. It is not improbable that the ferruginous matter has been carried to them, during the immense periods of time which have elapsed since these springs first appeared, by atmospheric waters trickling amidst the ferruginous materials of the ridge; the iron certainly appears to be accidentally there. I observed, also, that where these great quantities of the oxide of iron were, it was evident a stream of hot water had passed for a long period of time, and beneath the superincumbent deposite of carbonate of lime, which, as these hot waters have frequently changed their direction, might very well be. I perceived one considerable underground stream of hot water issuing from a cavity near the bank of the brook, and, upon examining it, found the process going on, iron depositing on the sides, and soft seams of sulphate of lime already established. Under these circumstances, I would not pronounce any of these waters to be natural chalybeates. It is probable that a great many mineral waters acquire some of their properties in transitu. I have supposed this to be the case in some sulphuretted springs I have seen, that rise through beds of slate and coal, loaded with sulphuret of iron, much of which may reasonably be thought, at particular depths, to be in a state of decomposition. For the carbonate of lime contained in these hot waters, we may infer a different origin; nor can we consistently assign to the prodigious quantity of caloric which has probably for such immense periods of time raised the temperature of these springs, any source short of those depths from whence the intrusive rocks, the veins of iron, and various other mineral phenomena of the vicinity, have sprung.

These thermal waters rise in a very limpid state, but as soon as they get into motion, and their parts become exposed to the atmosphere, a mineral deposite commences, attaching itself to dead leaves, to sticks, to any thing that serves for a point of adhesion; upon this deposite a brilliant green enamelled looking substance presents itself, which increases and thickens, in favorable situations, until it takes the thickness of half an inch. When this can be detached from the calcareous matter it covers, it has a vitreo-gelatinous appearance, somewhat of the consistency of those glairy substances produced in stagnant water in very hot weather. As long as the water runs over it, it continues to thicken and look green; but when the deposite has dammed up the course of the water, and another course is formed, which is constantly doing, then this green substance, being forsaken by the water, dries up, and crisps on the surface of the ground, like dead lichens. This dead stuff I examined with a powerful glass, and found that it was a mineral substance of a whitish gray color; on the under

Geological Reconnoissance.

In the

side it preserved still a deadish green appearance.
course of time it undergoes a change, and changes to a
deep black calcareous mould, on the surface of which I
found, as is frequently done in decomposing travertins, an
immense number of individuals of various species of helix.

From many other curious details respecting this mineral substance, which appears to have some affinity with the constituency of some prairies I afterwards visited in the vicinity of Red river, I must refer to those more detailed observations that will more appropria ely form part of the labor of some future leisure hours, when some experiments which I have to institute shall be matured. And in relation to an analysis of the mineral contents of the hot waters of the Washita, it was always my intention to have attempted one, after the best methods my very limited experience in operations of that kind permitted; and I had, on my departure from the Atlantic States, provided myself with such apparatus aud reagents as would have enabled me to produce some proxiniate results: but, upon leaving St. Louis, Missouri, perceiving it was more than doutful whether I should get my luggage through the mountains, and a speedy opportunity, as I thought, presenting itself, I sent it by water to the mouth of White river, and it had not reached Little Rock when I left that place for the Hot Springs. I was, therefore, compelled to content myself with some simple examinations of the waters, and with putting up carefully some bottles of them, in order, on my return, to submit them to the analysis of some distinguished chemists, better entitled to the confidence of those interested in the result than I claim to be; which analysis I hope ere long to be able to state, with the authority of the name of the analysts. That these waters annually perform very admirable cures of chronic complaints incident to southern climates, is well known there; and that their efficacy, and the beauty and salubrity of the country, will soon cause the place to be resorted to from far and near, as soon as proper accommodations for visiters can be prepared, is very obvious. They seein providentially placed there for the use of the inhabitants of the low lands in the vicinity of Red river, and their value deserves to be made extensively known.

About three miles northeast from the Hot Springs the country is mountainous and broken, consisting of cones and ridges from three hundred to five hundred feet above the streams, which meander in very narrow bottoms. If, in Missouri and the north parts of Arkansas, I had observed the singular propensity to subsitute siliceous for calcareous matter, here I found the ferruginous hills of old red sandstone, sometimes consisting of solid masses of flint, at other times of a beautiful novaculite, and again of ferruginous sandstone, with heavy veins of iron passing through them, and imparting a chalybeate character to miany springs issuing from their slopes. These hills contain that beautiful mineral substance called the Washita oilstone, which is sometimes well exposed in small vertical layers, and which adhere so tenaciously to each other that, on account of their remarkable brittleness, they are separated with mach difficulty. It is not easy, for this reason, to obtain good specimens of it. The curious gradations of this siliceous matter, in the forms of old red sandstone, flint, novaculite, hornstone, and quartzose rock, are surprising. For many miles these lofty hills present a succession of these minerals, in various forms. In some parts rock crystal abounds in great profusion, and of a good transparency and large dimensions: beautiful crystals of quartz, of a large size, are also found, with double terminations, and not unusually of a bright topaz yellow color. But the most remarkable mineral I saw was the novaculite, or oilstone, a siliceous stone of a pearly semi-transparent

The gaseous volume is insignificant, azote and a trace of carbonic acid; the solid contents are carbonate of lime, carbonate of iron, and a trace of sulphate of lime.

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nature, presenting singularly smooth natural faces, and occasionally tinged, in a very pleasing manner, with metallic solutions. Lofty hills are found there, composed entirely of this material. On one of these I saw several large pits, twenty or thirty feet deep, and as many in diameter, resembling inverted cones, the insides of which were covered with broken chips of this beautiful mineral, some white, some red, some carmine, some blue, some quite opalescent. In and near these pits round and long masses were scattered about, of a hard greenstone I had found in place eighteen miles distant, and none of them too large for the hand. They were, undoubtedly, Indian tools, and these were the quarries from whence the Indians had formerly obtained the materials they used for their arrow heads, and other weapons of offence. I found no arrow heads there, how. ever, but subsequently on many of the alluvial banks of the streams in the country around, amidst the circular holes and mounds, where their now fallen mud cabins formerly stood, prodigious quantities of chips of the same mineral, and of broken arrow heads also, were strewed around; from whence it may be inferred that they resorted to the mountains for pieces of the mineral, and carried it to their villages to fabricate. Although it is true that no flints have yet been found in the United States, in the chalk formation, yet, in Missouri and Arkansas, inexhaustible quantities of flint are to be obtained, of the best quality, and from the most accessible situations.

During my stay here, I endeavored in vain to procure a guide to cross the country with me to Cantonment Towson, on Red river, opposite the confines of the Mexican territory; in this direction, except for a short distance, there is not even a bridle path; all reads terminate here, and the passes are only known to the hunters; but heavy rains had set in, and the mountain streams were excessively swollen; the hunters, too, were averse to break off from their favorite pursuit of bear-hunting, which commences at this season. Deeming it imprudent to run the risks to which, under these circumstances, and at so late a period of the year, and without a hunter to provide me with food, I should have been exposed, I reluctantly gave up my intention of further exploring the hills in that direction, and accordingly directed my course to Red river, lower down the Washita.

The

This river runs upon the grauwacke slate which crops out in various parts of its banks, and it will deserve the attention of future travellers to examine, with great accuracy, the rocks in its vicinity, as I saw indications, which I had neither the time nor the means of effectually pursuing, of the existence of non-bituminous coal-a fact of great importance to the future prosperity of that part of the country. The anticipation, too, is strengthened by those important deposites of anthracite coal, in Pennsylvania and Virginia, being found in the transition formation. On my way I passed between the left bank of the Washita and Magnet Cove, leaving it to the northeast, and observed the same difference on this side, between the trees growing on it and the evergreens growing on the adjacent sandstone, which I had remarked on my advance. route led through a wild romantic country of flinty knobs, and little vales excellently watered. From the Washita to the Caddo river, for about thirty miles, the elevated parts of the country consist of the same siliceous knobs and uplands, some of them approaching to the oilstone of the Washita, and well watered by numerous streams, with limited bottoms of considerable fertility intervening. The myrica cerifera, or candle-berry myrtle, was very abundant on these siliceous lands; the deer also were in great numbers, as well as strong gangs of wild turkeys, strutting about in their finest plumage. These birds occasionally take flight with as strong a wing as the wild goose, and light upon the tallest trees. Three miles before I came to the Caddo, the country began to descend

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towards it, and nature began entirely to change her aspect. On crossing the river I entered upon an extensive level cane brake,* in a bottom of great fertility. Here I again found the tertiary limestone in the bed of the river, and in some adjacent bayous, with the fossils I had before seen at Little Rock. This is a favorite resort of parroquets and ivory-billed woodpeckers.† The plants are all deciduous; the old red sandstone, with its pines, is no longer seen, except at very distant intervals, where slight vestiges of it appear. The soil is of an excellent quality, and the bottoms are covered with laurel and holly, which last becomes a tree of considerable magnitude, having a diameter frequently of twelve inches. The almost impenetrable cane brakes, lying five or six miles on each side of the Washita, (into which the Caddo falls near where I crossed it,) and which are of very great breadth in some parts of its course to join Red river, and to where this last falls into the Mississippi, can never be reclaimed until levees are constructed to preserve the lands from inundation.

Not far from the junction of the Caddo with the Washita there are some salt brines, the natural strength of which it is impossible to measure whilst the soil is so saturated with river water; but eventually, when wells are sunk beneath the beds of the streams, and properly secured, there can be no doubt but that the country will possess salines adequate to its wants. I saw specimens of sulphate of lime, also, which induce me to think that deposites of that mineral may be found ere the wants of the country may require them. As a mineral manure, it would probably be found very valuable when applied to the siliceous soils north of the Caddo, as well as others yet to be men tioned, a little north and northeast of Red river.

From the Caddo to Tournois creek, the distance is about fifteen miles, always upon good level soil. Part of the country, however, was sandy, with heavy beds of a bluish green arenaceous clay, containing a trace of lime. I found no fossils or impressions in it, but was induced to believe it was the equivalent of some tertiary beds I had seen near Shirley, on James river, Virginia. The whole of this part of the country almost seems to be underiaid with rotten limestone, derived from broken down marine shells. The country hence, for several miles, consists of good bottom land, full of holly and laurel, with occasional hills of old red sandstone of moderate size, with their usual pine trees. Having gone about twenty miles, the country fell again to the south, and I soon came to an important stream which rises to the northwest, and empties into the Washita, called the Little Missouri, from its waters being of a dusky red, muddy color. On crossing this stream, I entered upon a dense low bottom of the richest soil, covered with cane, holly, laurel, and swamp timber, intersected by numerous bayous; this lasted for three miles, when the country began to rise a little again; and, after advancing a few miles, I came upon a singularly black waxy soil of a carbonaceous color, entirely different from any thing I had yet observed, except the surface of the travertin, at the Hot Springs, which, as I have before observed, was not dissimilar to this, agreeing further in the profusion of helices and other land shells with which it abounded. The country here appeared to consist of a chain of prairies running westward, and parallel with Red river for a very great distance. Some of these prairies were mere bald spots, of half an acre and upwards, surrounded by plants, whilst others were said to contain several hundred acres. In every instance they were surrounded with a belt of timber and plants peculiar to the country. I was informed by Judge Cross, a gentleman well acquainted with the country, and to whose intelligence and hospitality I owe many obligations, that these prairies extend probably many hundred miles to the west, and that

* Miegia macrosperma.

+ Picus principalis.

it is an opinion deserving of being entertained, that plants are encroaching upon the prairies generally. It was with sincere pleasure I found myself upon geological grounds, with which I was well acquainted. The prairies were covered with the fossils which, as I have before observed, characterize the New Jersey green sand formations," but the superficial soil was uniformly of a deep black color, resembling charred wood, and in wet weather is of a waxy, plastic consistency, that makes it extremely disagreeable to move amongst. Its fertility is remarkable, and renders it eminently fitted for cotton, which, as I had many opportunities of observing, succeeds well. The black soil, which is substantially calcareous, contains, as I found from slight experiments, a proportion of carbon.

This was one of the most lovely countries I had seen, a gentle rolling surface and fine woods, in which is an abun dance of the indigenous crab apple,† with the beautiful bow wood, ‡ or bois d'arc, as it is usually called. On examining where the streams had abraded the lower parts of the land, and digging in various places, I found that all these portions of the country, which consisted of prairie land, were bottomed upon immense beds of rotten limestone, derived from the testaceous remains of the mollusca I have named, entire shells of which in a soft state are still imbedded in the broken down masses once composed of shells. The zone of black land here does not appear to have a breadth of more than five miles; wherever it is, the same fossils are found, with the undervalves profusely scattered around on the surface. Sometimes the black earth gave place to a deep red marle of great fertility, but in this marle I found no shells; they seemed peculiar to the black prairie land. It was evident I was here upon an ancient floor of the ocean, from which we may infer it had retired with comparative tranquility, the surface being so little disturbed. The broken down marine shelly matter had accumulated into local beds and extensive hill deposites, after the manner in which we know some existing species accumulate, and the general irregularity of the surface was not dissimilar to that which is presented by the various soundings of marine coasts, where recent surfaces are forming. These accumulations are more or less covered with a vegeto animal deposite, that, by the constantly acting power of the elements, is partially removed, and carried by rains towards the streams; hence this covering is diminished in some places, and thickened in others. In some situations the black soil is two or three feet deep, whilst in others it is only a few inches thick, in which latter situations the tender roots of plants having, in extreme dry weather, to contend with a caustic calcareous bed, are liable to perish; the Indian corn, for this reason, is sometimes what is called fired, its leaves drying up and wasting away. These characteristics of the prairie country, as far as this particular zone of prairies is concerned, is common to a vast extent of country to the west of the points I examined. To the east the zone extends from north latitude 33° 40′ to north latitude 32° 30', in the State of Alabama, § and can be traced at intervals to north latitude 40° 20', in the State of New Jersey. Throughout this very extended line, all of which I have personally examined, the characteristic shells of this subcretaceous formation have been found. I possess gryphæa, exogyra, and other shells from localities far up the False Washita, the neighborhood of the Kiamesha, from Mount Prairie in Arkansas, from Mississippi, from Prairie Bluffs in Alabama, and from New Jersey, all of them identical; and in the subcretaceous deposites of Alabama, I have found the greatest profusion of the fossil equivalents of the genera peculiar to the green sand beds of Europe. I hope at no distant period to be able to trace with some pre

* Gryphæa convexa, exogyra costata, &c. &c.
Malus coronaria, twenty feet high, ten inches in diameter.
Maclura aurantiaca.

§ Wells, five hundred feet deep, have been dug through rotten lime stone, into slate with quartz.

Geological Reconnoissance.

cision, the ancient littoral bounds of that geological period, so clearly demarcated by all the unequivocal circumstances I have described.

In relation to those areas which have received the appellation of prairies, from their surfaces, denuded of timber, being at certain seasons covered with long grass, I am not of the opinion of those who think that all prairies have originally been produced by firing the timber annually, and thus, by repeated combustions, destroying the timber as well as the sprouts. That much ground has been denuded by such means, I would admit, and the cause certainly would appear a sufficient one for those prairie districts to which no other cause apparently could be assigned. By whatever method plants begin first to germinate in such deposites, it is evident, as I have before stated, that where the vegetable matter is thin, and the season unfavorable, they are liable to perish; and where they would not altogether perish, it must be remembered that this country was stocked, as the more distant prairies still are, with buffalo, which would, by their periodical occupation of the country in numberless herds, assist in exterminating plants of a vigorless constitution. These may be enumerated amongst the efficient causes of a prairie or meadow state of extensive tracts of country. This view of the subject is somewhat strengthened by the fact of plants, in modern times, encroaching on the prairies; for I have observed they encroach on the sides where vegetable matter has been washed and accumulated, finding a nutritious bed there, into which they can push their innumerable delicate fibres, secured from the devastating teeth and hoofs of the buffalo, which have now all left this part of the country; for where man settles, that animal never remains long. But there is also another view of the subject.

These vast prairies of the West, as well as the diminutive ones in question, must be admitted to be ancient floors of the ocean. When it abandoned them, they were, of course, without plants; and unless we admit their spontaneous growth, we must suppose them to have germinated from seeds derived from plants growing on lands which had been left with a higher level than the ocean, before it receded from these prairies. Their borders would, of course, be planted first, and thus we can conceive of every new generation of plants giving some of its seeds to the winds and the waters, and gradually extending the forests, like the present members of the human family, advancing upon and settling the country for the use of posterity. This seems a more natural and just method of accounting for the immense prairies of the West, and the pampas of the southern portion of the South American continent, than conjectural opinions founded on a convenient method adopted by the Indians of securing their game, and which they have practised at all times, certainly with the effect of thinning, but without destroying the timber, as we know from the immense forests of Virginia, Tennessee, Kentucky, Indiana, Missouri, and Arkansas, which were once annually fired by the Indians, to burn the high grass, that they might better see their game a practice which destroyed the undergrowth, but only thinned the trees; and now that the Indians have left these countries, we find the undergrowth rapidly occupying the ground again. Before we receive opinions altogether hypothetical in relation to the cause of the prairie condition of land, it seems as if we were bound to inquire what was their first condition, consistent with the geological fact that they are ancient floors of the ocean. It, therefore, appears to me to be probable that many of these prairies have never, since the ocean left them, been covered by any vegetables of greater importance than the gramina. Under this view of the matter, it is consistent to suppose, what is personally known to me to be the fact in many observed instances, that trees and plants may be transplanted to those prairies with perfect

success.

[25th CoNG. 1st SESS.

It has appeared proper to me, in drawing up an official report, which has for its object the practical advantages to be derived from geological investigations, to abstain from entering into the consideration of some of those particular branches of geology which impart at this moment so much interest to the scientific literature of Europe; and if I have inclined to the support of an igneous theory for the origin of the rocks in the inferior portion of the geological series, it is because I have been convinced, by a long study of the mineral phenomena connected with the primary rocks of this continent, that there is no other conclusion to which similar phenomena can ever probably lead my judgment; and I have no reason to suppose it is unsafe ground, since the most eminent cultivators of the science in Europe, upon an examination of their own continent, have come to the same opinion. The deliberate opinions of such men, enriched by all the aid that chemistry and other cognate branches of the science are susceptible of, are themselves authority. But I was chiefly led to express the opinions which are found in this report, respecting the supposed expansive power resulting from the igneous forces operating in the radial space, by the expectation that it would lead many ingenious minds, who had not turned their attention to the structure and origin of metallic rocks, to examine some interesting localities through the medium of these opinions, which, as they have never deceived me, would thus, I trusted, be useful to them. In this, as well as in all my investigations, I have been sincerely desirous of making my labors useful, rather than of embellishing them by any de. viation from a rigorous examination of facts, upon which all true and useful results depend.

The exigencies of society have reached a stage in Europe, to which we are advancing in this country. There, not only the metals, but every rock, every stone, every bed of sand or clay, has its value. A quarry of stone, of whatever quality, produces an income, and canals and railroads are the facilities which carry them cheaply to their destination. A very few years ago, geology, in this country, was merely considered a liberal branch of knowledge; now, it is universally deemed a science which teaches the true structure of the earth, and the most probable situations in which its metals and minerals are to be found. Before many years elapse, the study of the science will be general here, because the wants of society are enlarging. In the increasing desire manifested in the States to establish geological surveys, we have the evidence of this, and of the existence of a spirit that must lead to a very great development of the mineral resources of the country, as well as the extension of its intellectual character. But, in putting these State enactments into operation, it should never be lost sight of, that the advantages to be derived from investigations, the proper and sole objects of which are physical facts, depend entirely upon the practical experience of the persons to whom they are to be intrusted.

Geology, although it may be divided into four principal branches, mineralogy, conchology, ancient zoology,† and botany, has now become so far the study of universal na

*It is somewhat remarkable that New York, a State conspicuous above the other States for its immense resources, and distinguished for the great results which have been produced by the active enterpirse of its citizens, should be one of the very last to make those investigations which that eminent and lamented statesman, De Witt Clinton, so earnestly recommended many years ago to the Legislature. The citi zens of that State are too intelligent to be ignorant that the wealth and power that give great Britain so great an influence in the world mately be thrown upon her coal, as that country has long been, for are essentially drawn from her coal mines. This country must ultifuel for domestic purposes, and for the support of its manufactories. and in possession of the knowledge that her territory contains every And yet, with internal improvements that would distinguish any age, indication of coal, New York has taken no step to become acquainted with the extent of that portion of her mineral resources.

Amongst the numerous meritorious naturalists of this country, it would be unjust not to allude to the distinction Dr. Harlan, of Philadelphia, has attained by his accurate knowledge of comparative anato my, and his enlightened zeal in prom ting the cause of natural history.

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