Chapter XIII: Front Matter (13)

The leather tanned with it, has, in every instance, been superior to that tanned in a comparative experiment, with oak bark; being firmer, less porous, and at the same time more pliable. The reason for this difference, will probably be found in the _high state of oxygenizement_ of the bark, particularly of the epidermis, by which it is rendered to a certain degree acrid and corrosive. Dr. Bancroft was perhaps the first who noticed the oxygenizement of barks. He attributes the dark brown colour of the epidermis of _his_ quercitron, to this cause; and as a confirmation of the idea, I have observed that ink made of the epidermis of another kind of bark, though at first not to be distinguished by the colour from that made of the cellular and cortical parts, is incomparably less permanent.

As a material for making ink, the wood of the chesnut is probably unrivalled. Combined with iron in any proportion, it gives, as it is dilute or concentrated, a pure blue or blue-black; while galls, sumach, &c. &c. unless combined with a greater proportion than is consistent with the highest degree of permanency, afford a _black_ more or less inclining to a reddish brown. The lake of the chesnut is indeed a blue, and not to be distinguished by the eye from indigo; but when diffused on paper, this same substance becomes an intense shining black. In dying, little difference is observable between the chesnut and galls, and sumach, except that the former has a rather greater affinity for wool, &c. than the latter, and of course requires less boiling. Its permanency has been completely tested by long exposure to the sun and the weather; but no doubt can exist on this head, if the position of Berthollet be true, that permanent blacks are formed only by the combination of iron and tannin.

To prepare the chesnut wood for the purposes of tanning, a mode has been devised for reducing it to a suitable degree of fineness. This method consists in the application of knives, either in the direction of, or transversely to the grain, by a rotatory motion. This mode obviously involves the greatest possible economy of moving power. Messrs. B. and M. Stebbins, of West-Springfield, who are making arrangements for going largely into the exportation of the article, have in construction a machine upon this plan.

As might be expected, the inspissated aqueous extract of the chesnut, bears a near resemblance in many particulars, to catechu. Professor Dewey, of William's College, who at my request, has gone through an extensive and elaborate course of experiments, informed me that he obtained a quarter more of the gelatinous precipitate from the former, than from the latter. By the taste, the two substances are not to be distinguished, except that the former is more pungent. It leaves upon the tongue, the same permanent and refreshing sweetness, for which the other is so much prized in the east; where it is used as an article of luxury, with betel nut. Might not the extract be advantageously substituted for catechu, in the celebrated life preserving composition of Dr. Pearson; the object being to concentrate the greatest possible quantity of nutritious and tonic substances in the smallest weight.

The colouring properties of the two substances, are entirely different. After the discovery, twelve or fifteen years since, of the composition of the _terra japonica_, attempts were made in England to introduce it into the materia tingentia, as a substitute for galls; but unfortunately, like the extract of quercitron, it affords with iron nothing but a meagre olive; and Dr. Bancroft states, that in a great number of trials, he was unable, by the greatest accumulation, to produce any thing like a black, even upon wool, much less upon cotton and silk.

A singular fact, which I observed in the course of my experiments, is worthy of notice. I had prepared for a certain purpose, solutions from the wood of the trunk of a tree, about three feet, and from that of a limb about three inches in diameter. The same quantity of wood and of the solvent was employed in both cases. On adding to each the same quantity of the solution of gelatine, abundant precipitates immediately appeared, as usual, apparently much the same in quantity; but to my astonishment, the size of the several congeries in each, bore a near proportion to that of the sticks from which they were obtained, not differing much from that of middling and of very small flakes of snow. Is not this an extraordinary fact, evincive of a complication in the arrangement of these bodies hitherto unsuspected. May it not at some future period, lead to a _nomenclature of precipitates_; affording, like the crystallography of Haüy, a new and accurate mode of determining the compositions of substances; and perhaps throwing light upon the obscure subject of chemical, or if you please, electro-chemical affinities. The _size_ of a stick might probably be ascertained with almost as much precision, as by actual admeasurement. The solutions in this experiment, were formed by maceration in cold water. When hot water was employed, and the process was completed in two or three hours, the appearance of the precipitate was very different, the congeries being smaller, irregular, and not well defined.

I have only to add, that having taken measures to secure the discovery, both in this country and Europe, it is my wish to bring it into general use as speedily as possible.

I am, Sir, very respectfully,

Your obedient servant,

WILLIAM SHELDON.

P. S. In a short article for some future number, I may send you an account of the operation of the machine, and of some other particulars.

23. _Additional note concerning the Tungsten and Tellurium._

We have not room to insert in the present number, a description and a chemical examination of the ores of tungsten and tellurium recently discovered in Connecticut; they will appear in our next.

In the mean time it may be stated, that the tungsten and tellurium are found blended in the same pieces, but whether in mere mixture, or in chemical combination, is not yet quite determined. Many specimens of the tungsten exist without the tellurium, but every piece which has afforded tellurium has also afforded tungsten, and in greater abundance. Even in well defined crystals, both metals have been found in the same crystal, and where the external appearance was homogeneous. In other specimens a difference seems to be apparent, and a proper ore of tellurium appears to be blended with a proper ore of tungsten. This latter ore is the wolfram, composed of oxid of tungsten, or as some choose to say, tungstic oxid combined with iron and manganese. The crystals, however, are octahedral, a fact which we believe is not mentioned of this species by authors, although this form is found in the calcareous tungsten.

* * * * *

The Bismuth mine in which these ores are found is the property of Mr. Ephraim Lane. Letters addressed, post paid, to him at New Stratford, town of Huntington, Connecticut, will find him through the Post Office; and he will, for a reasonable compensation, pack boxes more or less extensive, for mineralogists and others. As Mr. Lane is by occupation a farmer, and is obliged to blast a quartz gangue in order to obtain his specimens, he cannot be expected to transmit them gratis. His mine, which has been sunk only ten feet, affords native bismuth, native silver, magnetical and common iron pyrites, and copper pyrites, (the two latter crystallized) galena, blende, tungsten, tellurium, &c.

It is expected that the shaft will soon be sunk deeper, when probably a more abundant supply of good specimens will be obtained.

N. B. The silver and galena are the least abundant.

_March 8th, 1819._

FOOTNOTES:

[28] Vide Edin. Review for Sept. 1818. p. 374.

[29] Referring to the ridges of Greenstone near New-Haven.

[30] Or, according to the Wernerian Geologists, Transition? _Editor._

[31] The modesty of the writer has prevented him from applying to the formations which he has well described, the terms _transition_ and _secondary_, which there can be little doubt do in fact belong to them. His strata of highly inclined limestone, appear to belong to the transition class of Werner, and his flat strata, to the secondary. It may be observed in this place, that the specimens alluded to in the text (passim,) appear to be correctly described by Mr. Cornelius, and to justify his geological inferences as far as hand-specimens seen at a distance from their native beds, can form a safe basis for general geological inductions. _Editor._

[32] Copied partly from Manuscripts of the late Dr. Muhlenberg, of Lancaster, Pennsylvania.

[33] This large species I understand has been mistaken by a writer on Natural History for _Boa constrictor_: this is mentioned to show how remotely it is possible to diverge from accuracy in this science.

[34] I have been since informed by Mr. Lesueur, that to his taste the poison was bitter.

[35] The terminal caudal plates of this individual were bifid, as in the one of Peale's Museum.

[36] This last is the animal, beyond a doubt, judging from the detailed description and plate, which has lately been erected into a new genus, under the name of Scoliophus..............................the identity is immediately obvious, to any one acquainted with the specific characters of the above-mentioned coluber. And I presume it can be made apparent, to any one tolerably versed in the science, should proof be thought necessary.

[37] Dr. Barton remarked that this part is rounded, (cauda teres,) this observation was not autoptical, but dictated most probably by the appearance of Catesby's figure. In the young animal the tail is less compressed than in the old one.

[38] Here we might properly enough notice the high-ways, streets, and pavements of cities, &c. on which the materials being minutely divided by attrition, are in a better state for the sun to act freely on, and will consequently yield greater products than equal areas of undisturbed surface, under like circumstances of heat.

[39] Perhaps there is no body in nature absolutely incombustible, but I use the term here in common acceptation.

[40] It may be easily proved that water evaporates (though slowly) at a temperature many degrees below its freezing point; and these vapours are more subtle and elastic than those formed at the boiling point of that fluid.

REMARK.

It is indeed proved that vapour is formed from water at the lowest temperatures, but is _less elastic_, the lower the temperature, as appears from its sustaining a continually decreasing column of mercury, the lower the temperature at which the vapour is formed. Vide Dalton's and Gay Lussac's experiments. _Editor._

[41] We have taken the liberty to give Mr. Atwater's Memoir a more extensive Title, for reasons that will be obvious on a perusal of the piece.

[42] Genus, _platanus_--species, _occidentalis_, popular name, sycamore, or button-wood.

[43] The collection of Mr. Perkins became, in 1807, (partly by the liberality of its possessor, and partly by purchase,) the property of Yale College, and is now in the cabinet of that institution. It is believed that few cabinets of equal extent, ever contained more instructive and beautiful specimens, with less that is unmeaning or superfluous. The cabinet of Dr. Bruce has, since his death, been purchased by a gentleman in New-York, for 5000 dollars. _Editor._

[44] On account of its peculiar cadaverous odour Dr. Hayden proposes to call this mineral (should it prove to be a new one) Necronite, from the Greek Νεκρος.

[45] That is, the inner bark deprived of the epidermis or outer bark, by the shaving knife.

CONTENTS.

GEOLOGY, TOPOGRAPHY, AND MINERALOGY.
Page

Art. I. On the Geology, Mineralogy, Scenery, and
Curiosities of Parts of Virginia, Tennessee, and
of the Alabama and Mississippi Territories,
&c. with Miscellaneous Remarks, &c. In a Letter to
the Editor. By the Rev. Elias Cornelius 317

Art. II. On the Origin of Prairies. By Mr. R. W. Wells 331

Art. III. Sketch of the Mineralogy and Geology of the
Vicinity of Williams' College, Williamstown,
Mass. By Professor Dewey, of Williams'
College, in a letter to the Editor 337

Art. IV. On the Tourmalines and other Minerals found
at Chesterfield and Goshen, Massachusetts, by
Col. George Gibbs 346

Art. V. Observations on the Minerals connected with
the Gneiss range of Litchfield county, by Mr.
John P. Brace, of Litchfield, Conn. 351

BOTANY.

Art. VI. An Account of two North American Species of
Rottböllia, discovered on the Sea-coast in the
State of Georgia, by Dr. William Baldwin, of
Philadelphia 355

Art. VII. Floral Calendar kept at Deerfield, Massachusetts,
with Miscellaneous Remarks, by Dr.
Stephen W. Williams, of Deerfield 359

Art. VIII. Description and Natural Classification of the
Genus Floerkea, by C. S. Rafinesque, Professor
of Botany and Natural History in the
Transylvania University, Lexington, Ken. 373

Art. IX. Descriptions of Three New Genera of Plants,
from the State of New-York. Cylactis, Nemopanthus,
and Polanisia, by Professor C. S. Rafinesque 377

Art. X. Notice on the Myosurus Shortii, by the same 379

Art. XI. Description of a New Species of Gnaphalium,
by Professor E. Ives 380

FOSSIL ZOOLOGY, &C.

Art. XII. Observations on some Species of Zoophytes,
Shells, &c. principally Fossil, by Thomas Say 381

PHYSICS, CHEMISTRY, &C.

Art. XIII. Observations on Salt Storms, and the Influence
of Salt and Saline Air upon Animal and
Vegetable Life. Read before the Lyceum of
Natural History of New-York, March 7,
1819, by John B. Beck, M. D. 388

Art. XIV. Thoughts on Atmospheric Dust. By Professor
C. S. Rafinesque 397

Art. XV. On the Effect of Vapour on Flame. By J. F.
Dana, Chemical Assistant in Harvard University,
and Lecturer on Chemistry and Pharmacy
in Dartmouth College 401

Art. XVI. Analysis of the Harrodsburg Salts, by Edward
D. Smith, M. D. Professor of Chemistry
and Mineralogy in the South-Carolina College 403

Art. XVII. Additional Notice of the Tungsten and
Tellurium, mentioned in our last Number 405

Art. XVIII. A Substitute for Woulfe's or Nooth's Apparatus,
by Robert Hare, M. D. Professor of
Chemistry in the Medical Department of the
University of Pennsylvania, and Member of
various Learned and Scientific Societies 410

Art. XIX. A New Theory of Galvanism, supported by
some Experiments and Observations made by
means of the Calorimotor, a new Galvanic
Instrument. Read before the Academy of
Natural Sciences, Philadelphia, by Robert
Hare, M. D. Professor of Chemistry in the
Medical Department of the University of
Pennsylvania, and Member of various Learned
Societies 413

MATHEMATICS.

Art. XX. An improved Method of obtaining the Formulæ
for the Sines and Cosines of the Sum and Difference
of two Arcs, by Professor Strong, of Hamilton College, &c. 424

MISCELLANEOUS.

Art. XXI. An Account of several Ancient Mounds, and of
two Caves, in East Tennessee, by Mr. John
Henry Kain, of Knoxville 428

Art. XXII. Facts illustrative of the Powers and Operations
of the Human Mind in a Diseased State 431

INTELLIGENCE.

Art. XXIII. 1. Discovery of American Cinnabar and
Native Lead 433

2. Theoretical Views of Professor Hare of
Philadelphia 434

3. New Work on Chemistry _ibid._

4. Botanical 435

5. Staurotide _ibid._

6. Supplement to the "Remarks on the Geology and
Mineralogy of a Section of Massachusetts, on
Connecticut River, &c." contained in No. 2,
Art. I, of this Journal, by E. Hitchcock, A. M. 436

7. New Process for Tanning 439

8. Connexion between Chemistry and Medicine _ibid._

9. Brucite _ibid._

10. Lithography _ibid._

Conclusion 440

_Postscript._--American Geological Society 442

Index 443

THE

_AMERICAN_

JOURNAL OF SCIENCE, &c.

_GEOLOGY, TOPOGRAPHY, AND MINERALOGY._

ART. I. _On the Geology, Mineralogy, Scenery, and Curiosities of Parts of Virginia, Tennessee, and of the Alabama and Mississippi Territories, &c. with Miscellaneous Remarks, &c. In a Letter to the Editor._ By the REV. ELIAS CORNELIUS.

(Concluded from page 226.)

I will conclude this part of the narrative with a brief notice of a few curiosities occurring in the region which has been described.

_Caves._

1. It is well known that it furnishes a great number of interesting _caves_. They are found alike in the inclined and horizontal strata. Some of them are several miles in extent, and afford fine specimens of earthy and alkaline salts.

Wier's cave in Virginia has been described by Mr. Kain. I have in my possession a map of its most important apartments, including its whole length, copied from a survey made by Mr. J. Pack in Oct. 1806; also the notes of another survey made in May 1816, by the Rev. Conrad Speece of Augusta county, and Mr. Robert Grattan; which, with an explanation, and particular description, I hope to be able to transmit to you at a future time.

From these surveys, it appears that the whole extent of the cave, hitherto discovered, does not exceed eight hundred yards. This was the length stated to me by the guide, when I visited it in August, 1817. I cannot but think there is some mistake in Mr. Kain's remark, that "it is a mile and a half in extent." I spent four hours in examining every accessible part, and by permission of Mr. Henry Bingham, the owner, made a large collection of specimens, which were transmitted for the Cabinet of Yale College.[46]

_The Natural Bridge._

2. My object m naming this celebrated curiosity, is not to give a new description of it, but merely to furnish a correct account of its dimensions. I visited it in company with the Rev. Mr. Huson, who had previously found its height by a cord, to be two hundred and ten feet. We now found it by the quadrant, to be two hundred and eleven feet, and the arch through the centre about forty feet.

Some have attempted to account for this great curiosity, by supposing that a convulsion in nature may have rent the hill, in which it stands, asunder; thus forming the deep and narrow defile, over which the rocky strata were left, which constitute its magnificent arch. If so; the sides should have corresponding parts. At a distance from the base, no such correspondence is perceptible. At the base, the rocks are more or less craggy and irregular. This led me to take the courses and distances of each side. The following was the result.

Eastern side presents 4 angular points.

1. N. 55° W. 1 chain. 09 links.
2. N. 72 W. 1 ------ 05½ ------
3. N. 57 W. 1 ------ 12½ ------
4. N. 50 W. 0 ------ 33 ------

Western side presents 3 angular points.

1. N. 50° W. 0 chain. 45 links.
2. N. 67 W. 1 ------ 12½ ------
3. N. 77 W. 1 ------ 44 ------

The chain used contained 50 links, equal to 33 feet and ⅓. The distance between the abutments at the north end of their bases, is 80 feet; at the south end, 66 feet. As they ascend, the distance is greater. These data give the following diagram.

Although considerable resemblance appears at the base, yet as no such correspondence is visible 40 feet above it, and the sides for the whole remaining distance to the arch, one hundred and thirty feet, lose their craggy appearance entirely, and present the smooth, irregular surface of the oldest rocks. I am led to think that the natural bridge is coeval with a very remote period of time. Nor is there any difficulty even in supposing it to have proceeded from the hand of the Almighty, as it is; for great and marvellous are all his works!

The following anecdote will evince the effect which the sight of the natural bridge produced on a servant, who, without having received any definite or adequate ideas of what he was to see, attended his master to this spot.

On the summit of the hill, or from the top of the Bridge, the view is not more awful than that which is seen from the brink of a hundred other precipices. The grand prospect is from below. To reach it you must descend the hill by a blind path, which winds through a thicket of trees, and terminates at the instant when the whole bridge with its broad sides and lofty arch, all of solid rock, appears perfectly in sight. Not one in a thousand can forbear to make an involuntary pause: but the servant, who had hitherto followed his master, without meeting with any thing particularly to arrest his attention, had no sooner arrived at this point, and caught a glance of the object which burst upon his vision, than he fell upon his knees, fixed in wonder and admiration.

_A River flowing from a Cave._

3. I will next mention _a singular cave_, which I do not remember ever to have seen described. It is situated in the Cherokee country, at Nicojack, the north-western angle in the map of Georgia, and is known by the name of the Nicojack cave. It is 20 miles S. W. of the Look-Out mountain, and half a mile from the south bank of the Tennessee River. The Rackoon mountain in which it is situated, here fronts to the northeast. Immense layers of horizontal limestone form a precipice of considerable height. In this precipice the cave commences; not however with an opening of a few feet, as is common; but with a mouth fifty feet high, and one hundred and sixty wide. Its roof is formed by a solid and regular layer of limestone, having no support but the sides of the cave, and as level as the floor of a house. The entrance is partly obstructed by piles of fallen rocks, which appear to have been dislodged by some great convulsion. From its entrance, the cave consists chiefly of one grand excavation through the rocks, preserving for a great distance the same dimensions as at its mouth.

What is more remarkable than all, it forms for the whole distance it has yet been explored, a walled and vaulted passage, for a stream of cool and limpid water, which, where it leaves the cave, is six feet deep and sixty feet wide. A few years since, Col. James Ore of Tennessee, commencing early in the morning, followed the course of this creek in a canoe, for three miles. He then came to a fall of water, and was obliged to return, without making any further discovery. Whether he penetrated three miles up the cave or not, it is a fact he did not return till the evening, having been busily engaged in his subterranean voyage for twelve hours. He stated that the course of the cave after proceeding some way to the southwest became south; and southeast by south, the remaining distance.

_Natural Nitre._

The sides of the principal excavation present a few apartments which are interesting, principally because they furnish large quantities of the earth from which the nitrate of potash is obtained. This is a circumstance very common to the caves of the western country. In that at Nicojack, it abounds, and is found covering the surfaces of fallen rocks, but in more abundance beneath them. There are two kinds, one is called the "clay dirt," the other the "black dirt;" the last is much more strongly impregnated than the first. For several years there has been a considerable manufacture of saltpetre from this earth. The process is by lixiviation and crystallization, and is very simple. The earth is thrown into a hopper, and the fluid obtained, passed through another of ashes, the alkali of which decomposes the earthy nitrate, and uniting with its acid, which contains chiefly nitrate of lime, turns it into nitrate of potash. The precipitated lime gives the mass a whitish colour, and the consistence of curdled milk. By allowing it to stand in a large trough, the precipitate, which is principally lime, subsides, and the superincumbent fluid, now an alkaline, instead of an earthy nitrate, is carefully removed and boiled for some time in iron kettles, till it is ready to crystallize. It is then removed again to a large trough, in which it shoots into crystals. It is now called "rough shot-petre." In this state it is sent to market, and sells usually for sixteen dollars per hundred weight. Sometimes it is dissolved in water, reboiled, and recrystallized, when it is called refined, and sells for twenty dollars per hundred. One bushel of the clay dirt yields from 3 to 5lbs. and the black dirt from 7 to 10lbs. of the rough shot-petre. The same dirt, if returned to the cave, and scattered on the rocks, or mingled with the new earth, becomes impregnated with the nitrate again, and in a few months may be thrown into the hopper, and be subjected to a new process.

The causes which have produced the nitric salts of these caves, may not yet have been fully developed. But it is highly probable, they are to be ascribed to the decomposition of animal substances.

It is reasonable to suppose, that in an uncultivated country they would become the abodes of wild animals, and even of savage men. That they have been used by the natives as burial places, is certain. In one which I entered, I counted a hundred human skulls, in the space of twenty feet square. All the lesser and more corruptible parts of each skeleton had mouldered to dust, and the whole lay in the greatest confusion. I have heard of many such caves, and to this day some of the Indians are known to deposit their dead in them. From the decomposition of such substances, it is well known the acid of the nitric salts arises, and it would of course unite with the lime every where present, and form nitrate of lime.

_Mounds._

4. I have but one more article of curiosity to mention under this division. It is one of those artificial _mounds_ which occur so frequently in the western country. I have seen many of them, and read of more. But never of one of such dimensions as that which I am now to describe.

It is situated in the interior of the Cherokee nation, on the north side of the Etowee, vulgarly called Hightower River, one of the branches of the Koosee. It stands upon a strip of alluvial land, called _River Bottom_. I visited it in company with eight Indian chiefs. The first object which excited attention was an excavation about twenty feet wide, and in some parts ten feet deep. Its course is nearly that of a semicircle; the extremities extending towards the river, which forms a small elbow. I had not time to examine it minutely. An Indian said it extended each way to the river, and had several unexcavated parts, which served for passages to the area which it encloses. To my surprise, I found no embankment on either side of it. But I did not long doubt to what place the earth had been removed; for I had scarcely proceeded two hundred yards, when, through the thick forest trees, a stupendous pile met the eye, whose dimensions were in full proportion to the intrenchment. I had at the time no means of taking an accurate admeasurement. To supply my deficiency, I cut a long vine, which was preserved until I had an opportunity of ascertaining its exact length. In this manner I found the distance from the margin of the summit to the base, to be one hundred and eleven feet. And judging from the degree of its declivity, the _perpendicular height_ cannot be less than seventy-five feet. The circumference of the base, including the feet of three parapets, measured one thousand one hundred and fourteen feet. One of these parapets extends from the base to the summit, and can be ascended, though with difficulty, on horseback. The other two, after rising thirty or forty feet, terminate in a kind of triangular platform. Its top is level, and at the time I visited it, was so completely covered with weeds, bushes, and trees of most luxuriant growth, that I could not examine it as well as I wished. Its diameter, I judged, must be one hundred and fifty feet. On its sides and summit, are many large trees of the same description, and of equal dimensions with those around it. One beach-tree, near the top, measured ten feet nine inches in circumference. The earth on one side of the tree, was three and a half feet lower than on the opposite side. This fact will give a good idea of the degree of the mound's declivity. An oak, which was lying down on one of the parapets, measured at the distance of six feet from the butt, without the bark, twelve feet four inches in circumference. At a short distance to the southeast is another mound, in ascending which I took thirty steps. Its top is encircled by a breastwork three feet high, intersected through the middle with another elevation of a similar kind. A little farther is another mound, which I had not time to examine.

On these great works of art, the Indians gazed with as much curiosity as any white man. I inquired of the oldest chief, if the natives had any tradition respecting them; to which he answered in the negative. I then requested each to say what he supposed was their origin. Neither could tell: though all agreed in saying; "they were never put up by our people." It seems probable they were erected by another race, who once inhabited the country. That such a race existed, is now generally admitted. Who they were, and what were the causes of their degeneracy, or of their extermination, no circumstances have yet explained. But this is no reason why we should not, as in a hundred other instances, infer the existence of the cause from its effects, without any previous knowledge of its history.

In regard to the objects which these mounds were designed to answer, it is obvious they were not always the same. Some were intended as receptacles for the dead. These are small, and are distinguished by containing human bones. Some may have been designed as sites for public buildings, whether of a civil or religious kind; and others no doubt were constructed for the purposes of war. Of this last description, is the Etowee mound. In proof of its suitableness for such a purpose, I need only mention that the Cherokees in their late war with the Creeks, secured its summit by pickets, and occupied it as a place of protection for hundreds of their women and children. Gladly would I have spent a day in examining it more minutely; but my companions, unable to appreciate my motives, grew impatient, and I was obliged to withdraw, and leave a more perfect observation and description to some one else.

_Alluvial Formation._

I will now call your attention to the last geological division which came under my observation. It is the alluvial tract, extending from the Dividing Ridge already mentioned, to the Gulf of Mexico. This Ridge is the last range of high land which I crossed on the journey to New Orleans, and lies about six hundred miles north of the Gulf of Mexico. Its course at the place I crossed it, is a little south of west. It divides the waters of the Tennessee from those which proceed directly to the gulf. Travellers always observe it. They often mentioned it to me as the southern boundary of the _stony country_. After crossing it, you see no more limestone; and, which excites more joy in the traveller, no more of the silicious gravel, with which it is associated, and which is so troublesome to the feet of horses. The soil consists of a soft clay, or light sand, on which you seldom meet with a stone of any kind. The surface of the earth is undulating and hilly, but not mountainous. The water-courses do not move rapidly and tumultuously, as in the limestone country; but form in the soft earth, deep trenches, through which they glide smoothly and silently along. The smallest rivulet often has a trench ten feet deep; and the earth over which it passes, is continually yielding to its gentle attrition.

The only minerals which I observed, are sandstone, common and ferruginous; silicious pebbles in beds of creeks, and occasionally on the uplands; earthy ores of iron, particularly red oxides, and petrifactions of shells, wood, &c. In addition to these, it may here be mentioned that galena has been found in small quantities at Gibson's Port, and at Ellis's Cliffs, in the State of Mississippi: a crystal of amethyst, in the same state, by Mr. Blannerhassett; and a great variety of useful ochres, in many places on the banks of the Mississippi.

In the geological map attached to Professor Cleaveland's Mineralogy, the alluvial country bordering on the Gulf of Mexico, is represented as terminating at Natchez. But why its termination is placed here, I am unable to understand. The country above and below Natchez, so far as it has come under my observation, presents no difference of appearance in its geology, or mineralogy. I am aware that at Natchez, when the water of the Mississippi is lowest, a soft rock is seen, from which lime has been obtained. But this rock is two hundred feet below the surface of the adjoining country; and admitting that it is a limestone rock, there is no difficulty in supposing it may constitute the basis of the alluvial deposit which rests upon it. That the incumbent earth is _alluvial_, can be doubted, I think, by no one who has had an opportunity of examining it. By means of a road, which has been cut obliquely down the side of the bluff, distinct layers of clay, sand, and pebbles, have been exposed for the whole distance from the summit to the base. The same character is observed at a distance from the river, where the earth has been excavated by washing, or digging. In the vicinity of the town, there is a curious exhibition of the fact. A stream of water has worn away the earth to the depth of fifteen or twenty feet, and is continually lengthening the chasm, in the direction opposite to its own course. Thus, as the water flows from the town, the chasm approaches it. In examining the cause of this fact, I perceived it was owing chiefly to the difference of cohesion in the alluvial deposits, of which the earth is formed. That at the surface, being a thick loam, wears away with more difficulty than the deposit below it, which consists of a loose sand. The consequence is, that the water, which has once obtained a perpendicular passage of a few inches through the first, washes away the second with such rapidity, that it is constantly undermining it. This occasions a perpetual caving in of the surface, in a direction opposite to the course of the stream. The same fact is observed in many parts of the country for a great distance above Natchez. If there be wanting any other fact to prove that the earth on which the town of Natchez stands, is alluvial, it is found in the effect which the Mississippi has upon the base of the Natchez bluff. In consequence of a bend in the river, the whole force of its current is thrown against this base. If it consisted of solid rock, the river would probably have no effect upon it; but of such loose and friable materials is it composed, that the river is continually undermining it, and producing effects not less to be dreaded than those of an earthquake. Several years ago, a great number of acres sunk fifty feet or more below the general surface of the hill; and in 1805, there was another caving of that part directly over the small village at the landing. Several houses were buried in consequence of it, and strong fears are entertained by the inhabitants, that the same cause will yet submerge in the Mississippi, the whole of the present landing-place.

These facts, I think you will say, furnish satisfactory evidence of the alluvial character of the country at Natchez. The same character belongs to the whole extent south of the Dividing Ridge. This may be safely inferred from the general features of the country. But I have two facts, of a geological kind, to mention, both of which go to confirm the opinion.

1. A well was dug in the Choctaw nation, at the agency of the United States, in the year 1812 or 1813, under the direction of Silas Dinsmore, Esq. the agent. The excavation was continued to the depth of one hundred and seventy-two feet. No water was found. At no great distance from the surface, marine exuviæ were found in abundance. The shells were small, and imbedded in a soft clay, similar to marine earth. This formation continued till the excavation ceased. Dispersed through it, were found lumps of selenite, or foliated gypsum, some of which were half as large as a man's fist. Specimens of the earth, the exuviæ, and the selenite, have been transmitted for your examination. This excavation was made one hundred and twenty miles north northeast of Natchez. The Pearl River is four miles to the east of the place, and is the only considerable stream in this part of the country.

2. In the Chickasaw nation, one hundred and seventy miles north of the Choctaw agency, commence beds of oyster-shells, which continue to be seen at intervals for twelve miles. Four miles from the first bed, you come to what is called "Chickasaw Old Town," where they are observed in great abundance. They are imbedded in low ridges of a white marl. They appear to be of two kinds. Specimens of each, and also of the marl, you have received. "Chickasaw Old Town," is a name now appropriated to a prairie, on a part of which there formerly stood a small village of Chickasaws. The prairie is twenty miles long, and four wide. The shells occur in three places as you cross it, and again, on two contiguous hills to the east of it, at the distance of four miles. They do not cover the surface merely. They form a constituent part of the hills or plains in which they are found. Wherever the earth has been washed so as to produce deep gutters, they are seen in greatest abundance. Nor are they petrifactions, such as are found in rocks. They have the same appearance as common oyster-shells, they lie loose in the earth, and thus indicate a comparatively recent origin. They occur _three hundred miles_ northeast of Natchez, and but _sixty_ miles south of the Dividing Ridge.

If the country north of Natchez is alluvial, no one will doubt it is so from this place to the Gulf of Mexico. At Baton Rouge, one hundred and forty miles north of New Orleans, you meet the first elevated land in ascending from the gulf. The banks of the Mississippi are higher than the interior, and would be annually overflowed by the river, but for a narrow embankment of earth about six feet high, called the Levee. By means of this, a narrow strip of land, from half a mile to a mile in width, is redeemed, and cultivated with cotton and the sugar cane, to the great advantage of the planter. Generally, within one mile from the river, there is an impenetrable morass. The country has every where the appearance of an origin comparatively recent. Not a rock on which you can stand, and no mountain to gladden the eye; you seem to have left the older parts of creation to witness the encroachments which the earth is continually making upon the empire of the sea; and on arriving at the mouth of the Mississippi, you find the grand instruments of nature in active operation, producing with slow, but certain gradations, the same results.

_A destructive Insect._

But I will not enlarge on a fact already familiar. I will ask your further indulgence only, while I communicate an authentic and curious fact for the information of the zoologist.

In the Choctaw country, one hundred and thirty miles northeast of Natchez, a part of the public road is rendered famous on account of the periodical return of a poisonous and destructive fly. Contrary to the custom of other insects, it always _appears_ when the _cold weather_ commences in December, and as invariably _disappears_ on the approach of _warm weather_, which is about the first of April. It is said to have been remarked first in the winter of 1807, _during a snowstorm_; when its effects upon cattle and horses were observed to be similar to those of the gnat and musqueto, in summer, except that they were more severe. It continued to return at the same season of the year, without producing extensive mischief, until the winter of 1816, when it began to be generally fatal to the horses of travellers. So far as I recollect, it was stated, that from thirty to forty travelling horses were destroyed during this winter. The consequences were alarming. In the wilderness, where a man's horse is his chief dependence, the traveller was surprised and distressed to see the beast sicken and die in convulsions, sometimes within three hours after encountering this little insect. Or if the animal were fortunate enough to live, a sickness followed, commonly attended with the sudden and entire shedding of the hair, which rendered the brute unfit for use. Unwilling to believe that effects so dreadful could be produced by a cause apparently trifling, travellers began to suspect that the Indians, or others, of whom they obtained food for their horses, had, for some base and selfish end, mingled poison with it. The greatest precaution was observed. They refused to stop at any house on the way, and carried, for the distance of forty or fifty miles, their own provision; but after all suffered the same calamities. This excited a serious inquiry into the true cause of their distress. The fly, which has been mentioned, was known to be a most singular insect, and peculiarly troublesome to horses. At length it was admitted by all, that the cause of the evils complained of could be no other than this insect. Other precautions have since been observed, particularly that of riding over the road infested with it _in the night_; and now it happens that comparatively few horses are destroyed. I am unable to describe it from my own observation. I passed over the same road in April last, only two weeks after it disappeared, and was obliged to take the description from others. Its colour is a dark brown; it has an elongated head, with a small and sharp proboscis; and is in size between the gnat and musqueto. When it alights upon a horse, it darts through the hair, much like a gnat, and never quits its hold until removed by force. When a horse stops to drink, swarms fly about the head, and crowd into the mouth, nostrils, and ears; hence it is supposed the poison is communicated inwardly. Whether this be true or not, the most fatal consequences result. It is singular, that from the time of its first appearance, it has never extended for a greater distance than forty miles, in one direction, and usually, it is confined to fifteen miles. In no other part of the country has it ever been seen. From this fact, it would seem probable that the cause of its existence is local. But what it is, none can tell. After the warm weather commences, it disappears as effectually from human observation, as if it were annihilated. Towards the close of December it springs up all at once into being again, and resumes the work of destruction. A fact, so singular, I could not have ventured to state, without the best evidence of its reality. All the circumstances here related, are familiar to hundreds, and were in almost every man's mouth, when I passed through the country. In addition to this, they were confirmed by the account which I received from Col. John M'Kee, a gentleman of much intelligence and respectability, who is the present agent of the general government for the Choctaw nation. He has consented to obtain specimens of the insect for your examination, when it returns again; and will, I hope, accompany the transmission with a more perfect description than it has been possible for me to communicate.

In concluding this narrative of facts, I should be glad to take a comprehensive view of the whole. The bold features in the geology of the United States, as they are drawn by the Blue Ridge, the Cumberland with its associated mountains, and the Dividing Ridge, deserve to be distinctly and strongly impressed upon the mind. Such is the order and regularity of their arrangement, that they can hardly fail to conduct the attentive observer to important results. What has now been said of them, is but an epitome of the whole. I trust the public will soon read, in the pages of your Journal, a detail more perfect and more interesting. And allow me to suggest, whether, under the auspices of our learned societies, some men of science might not be employed and supported in exploring the country, with the prospect of greatly enlarging the science of our country, and of enriching our Journals and Cabinets of Natural History. Tours of discovery have often been made for other objects, and with success. Our country yields to no other in the variety, or the value of its natural productions. We owe it to ourselves and to the world, to search them out with diligence and without delay.

_Somers, (N. Y.) Oct. 1818._

ART. II. _On the Origin of Prairies._

_St. Louis, (Missouri Ter.) March 3, 1819._

SIR,

The probable cause of the origin and continuance of _prairies_ has been the subject of much speculation among the learned and curious. The inquiry is interesting; and many theories have arisen; but although plausible and ingenious, they are, in my opinion, unfounded in fact.

I should be glad to see the following remarks, which were called forth more particularly by the speculations of Caleb Atwater, Esq. (See No. 2. p. 116. of this work) appear in your valuable Journal of Science; and they are, for that purpose, at your service.

With high respect, I am, Sir, your's,
R. W. WELLS.

_Benjamin Silliman, Esq._

Mr. Atwater, after describing the prairies and barrens, says, that according to the common opinion, they "were occasioned entirely by the burning of the woods," but, "erroneous information first propagated such an opinion, and blind credulity has extended it down to us." Mr. A. goes on to affirm that, "wherever prairies and barrens are found, there, for a long space of time, water once stood, but was gradually drained off." The writer of this having often visited and observed with attention the nature and appearance of the prairies on the Alleghany mountains, in the states of Ohio, Indiana, and Illinois, and having long been employed by the United States as a surveyor in the prairie country of the Missouri and Missisippi, thinks he may venture to oppose these speculations without being thought presumptuous. He is of opinion, that the vast prairies and barrens, extending over the greater part of the western states, and over nearly all Louisiana, were primitively occasioned, and have been since continued, by the _combustion of vegetables_, and that _water_ had no agency in their formation.

In order to prove the high prairies of the state of Ohio to have been once covered by the waters of Lake Erie, Mr. A. maintains, that the channel of the Niagara river has been worn down "_several hundred feet_" by the attrition of its waters. Mr. A. should have shown, that the banks of the Niagara are, at this time, several hundred feet high, or, like the Potomac, at Harper's Ferry, has broken through a mountain "several hundred feet" high; but neither the one nor the other is the fact; the face of the country, on either side of the river, is comparatively low and champaign; and were it possible for the waters of the lake to rise considerably above their present level, they would meet with no obstruction or impediment, for many miles on either side the river, but would be precipitated over the cataract, into Ontario, and down the St. Lawrence to the Atlantic. But supposing there had been a mountain running between Lakes Erie and Ontario of sufficient height to prevent the water of the former from passing into the latter, it must evidently have found other places through which to escape, and before it would rise high enough to overflow the elevated region of Madison and Fayette counties, in Ohio, it would have passed over into the heads of the Alleghany. But it is impossible to imagine this, unless we suppose the Atlantic to have been six or seven hundred feet higher than at present, which, according to Mr. A. would have made prairie of all the Atlantic states.

The fact of shells and other marine substances having been found in a few places, by digging in the prairies, proves nothing, or proves too much, for they are found in equal or greater quantities all over America, in the sides and near the summit of the Alleghany mountains; on the Andes, in South America, and the Alps, in Europe. The resemblance which the soil, in the low prairies, and not in the high, bears to the _alluvial_, can justly be attributed, it is presumed, to the leaves and other vegetables and light materials of which they are composed, having been washed by heavy rains, for ages past, from the higher to the lower places. This will also account for the circumstance of trees growing upon the summits of the hills of steep ascent: being thin and poor, the grass neither grows sufficiently long or thick to kill the timber when fired. They _could not_ have been islands in this fairy lake; because their summits are frequently much _lower_ than high prairie flats a few miles distant. These are facts which will be recollected by those who have ever travelled through a prairie country of any extent.

But suppose it to have been proved, that the waters of Lake Erie once overspread the state of Ohio, from its present shore to Chillicothe, (a supposition which I trust has however been shown to be visionary) does it follow that the prairies were occasioned by such overflowing? If the water, by covering the country, prevented the timber from growing, should we not naturally look for the largest timber on the higher grounds which would be first forsaken by the waters, and for small timber on the low grounds, where the water remained longest? If this be true, (and it is unquestionable) we should then look for prairies on the low grounds bordering on Lakes Erie, Huron, and Michigan; and the thickly timbered country would be on the high land, near the sources of the rivers. But the contrary is absolutely the fact: we find heavy timbered land, and no _prairies_, in the low countries north of the lakes, and none south, either in Michigan territory or elsewhere, until we arrive near the sources of the rivers. It is true, that the water standing in ponds will prevent the timber from growing; but the difference is readily observed between prairies, properly so called, and those bogs.

But to prove farther that water had no agency in bringing the prairies into existence, we may mention those on and near the summit of the Alleghany mountains, (principally in Alleghany County.[47]) Many of those prairies are ten or twelve miles in length, and three or four in width. Will it be pretended that the sides of those mountains were also lakes? Farther--the most extensive prairies known, are the very high plains immediately west of the Rocky Mountains, and east of the mountains near the sources of the Arkansaw and Missouri rivers, extending even on the spurs of those mountains; a country the highest perhaps in North America, with a great and continued descent to the Pacific on the one side, and to the Gulf of Mexico on the other.

The barrens, also, found in Kentucky, are another evidence that water had no agency in their formation--they are situate, it is believed, in the elevated parts of the country exclusively.

The writer of this, deeming it unnecessary to say more, or to produce more facts, (although much more may be said, and many more facts produced) to prove that prairies were not lakes, will now endeavour to prove that they were occasioned by the _combustion of vegetables_.