Chapter VI: Front Matter (6)

To the traveller, who for several days traverses these prairies and barrens, their appearance is quite uninviting, and even disagreeable. He may travel from morning until night, and make good speed, but on looking around him, he fancies himself at the very spot whence he started. No pleasant variety of hill and dale, no rapidly running brook delights the eye, and no sound of woodland music strikes the ear; but, in their stead, a dull uniformity of prospect "spread out immense." Excepting here and there a tree, or a slight elevation of ground, it is otherwise a dead level, covered with tall weeds and coarse grass. The sluggish rivulets, of a reddish colour, scarcely move perceptibly, and their appearance is as uninviting to the eye, as their taste is disgusting to the palate. Such are the prairies and barrens of the west; but, in order to make ample amends for any deficiency, nature has made them exuberantly fertile. The farmer who settles upon them, by raising cattle, becomes rich with little labour. He ditches those which are too moist for grain; he ploughs and fences them, and raises from seventy to one hundred bushels of maize or Indian corn to the acre, without ever hoeing it. The United States own thousands and thousands of acres of such land in these western States and territories, which, for prompt payment, may be purchased for one dollar and sixty-two and a half cents an acre. One objection to these lands is, the want of timber for fuel and other purposes; and another is, that they are unhealthy: but in many places there is an abundance of peat in the wet prairies, and cultivation will every year render them more and more healthy. Some of them have been cultivated for fifteen or twenty years past with grain, and are as fertile as they ever were. As M. Volney says, "They are the Flanders of America."

Yours, &c. C. A.

ART. III. _Account of the Coal Mines in the vicinity of Richmond, Virginia, communicated to the editor in a letter from Mr._ JOHN GRAMMER, _Jun._

PETERSBURGH, _Virg. Jan. 28th, 1818_.

_Dear Sir_,

In compliance with your request, that I would send you some account of the Virginia coal pits, I paid a visit to them soon after my return, in company with Mr. R. W. Withers, and I will now proceed to give you the account proposed.

The pits, which we made the particular object of our visit, are situated in the county of Chesterfield, about 14 miles distant, in a direction W. S. W. from Richmond, and 3 miles south of James' River. The country rises gradually from Richmond to the pits; and, from its sandy appearance, is evidently an alluvial deposit, although its substratum is the granite mentioned by Mr. M'Clure, as extending through this state from S. S. W. to N. N. E. The coal is found on the western or upper surface of the granite, coincident with it both in direction and inclination; but whether they come immediately in contact or not, has not yet been ascertained. The 'bed' of coal is supposed by the miners to be coextensive with the granite, and I can discover no very good reason for disagreeing with them in this particular; but, on the contrary, many circumstances concur to strengthen the opinion that it is really coextensive with the granite. The coal is now procured from at least 25 different pits, opened at convenient distances through an extent of from 50 to 70 miles. It every where commences at the upper surface or termination of the body of granite. Some suppose that it is imposed on the granite; and others, that a thin stratum of slate is interposed between the coal and granite. It is always found covered by the slate. The granite is inclined to the horizon at an angle of 45°, and the coal has the same inclination. And since the coal, as far as it has been discovered, is found to accompany and correspond with the granite, why may we not suppose that it continues to accompany the granite, where it has not yet been discovered? At Heth's pits, the coal is 50 feet thick, measured on a line perpendicular to the surfaces of the extreme strata. At some of the pits between Heth's and James' River, it is 30 feet thick; and at the river, not more than 25 feet. The thickness of the coal on the north side of James' River, at the pits in Henrico and Hanover counties, is variable, but at no place greater than 25 feet; and to the south of Heth's, in the pits extending to the Appomatox river, it is still less thick. These facts would induce the supposition, that the coal was deposited in a bed, near the centre of which Heth's pits were sunk. But, on the other hand, the coal is distinctly stratified, and the number of strata increases as the coal proceeds from the surface of the earth; of course, therefore, the farther you proceed from the outer extremity of the coal, the thicker the body of it will be found; and from the inclination of the coal, the farther you are from its outer extremity the deeper it must be under the surface of the earth. Heth's pits are 100 feet deeper than any that have yet been sunk; and all the pits, that I have seen, appear to be nearer to the outer extremity of the coal. We may conclude, therefore, that if the others had been sunk as far from the outer extremity, they would have been as deep, and the coal would have been found as thick in them as in Heth's. Heth's pits, now so called, were first opened about 30 years since, and worked to some considerable extent. Experiencing, however, much inconvenience from the near approach of the works to a part of the coal which was on fire; and finding, from their unskilful mode of mining, that the business was not profitable, they abandoned the works, and filled up their shaft. Some few years after, Mr. Heth obtained possession of the land; and, having imported two Scotch miners, commenced working the coal again. He has now three shafts open, in a line with each other, in the direction of the vein. They are sunk near the brink of a steep hill, which rises about 180 feet from the western bank of a small brook. The depth of one of the shafts is 350 feet. The other two are about 300 feet deep, each. A steam-engine, constructed by Bolton & Watt, is erected at the middle and deepest shaft. It is used exclusively for pumping out water; but I will not trouble you with an account of the _modus operandi_, as it would be only a repetition of your own description of the same operation at the Cornwall mines. The coal is raised in a box, called by the miners a _cowe_. These cowes contain about two bushels each, and two of them are alternately rising and descending in each shaft. They are raised by means of ropes, fastened to a simple wheel and crank, which is turned by mules. In sinking their shafts, they cut, in the first place, perpendicularly (i. e. to the surface of the earth) through the coal, to its lower surface; and then turning westwardly, they open a horizontal gallery through the inclination of the vein, to its upper surface; by this means, to use their own terms, "gaining a double cut on it." Their principal gallery passes (in the direction of the vein,) by the mouth of each shaft. Its length is 1350 feet, and it is terminated at each end by a hitch or dyke of hard sandstone. (The passage was stopped with rubbish in such a manner as to prevent me from seeing the stone myself, and the gentleman who escorted me through the mines is my authority for its being sandstone; he might possibly, however, have been mistaken, as it is difficult to ascertain what a stone is, in such a place, until it is broken.) When I was at the pits, they were preparing to blast through this rock. At right angles to the principal gallery, they have opened, at convenient distances apart, shorter galleries, running westwardly, and these are again connected by passages parallel to the first or principal gallery. Pickaxes are the only tools used in working the coal, as it breaks very readily, in the direction of the strata. The roofs of some of the passages are perfectly smooth; and in such, the light of the lamps, reflected from the great variety of colours in the coal, presents a very brilliant sight. The gloomy blackness, however, of most of the galleries, and the strange dress and appearance of the black miners, would furnish sufficient data to the conception of a poet, for a description of Pluto's kingdom. A strong sulphurous acid ran down the walls of many of the galleries; and I observed one of the drains was filled with a yellowish gelatinous substance, which I ascertained, on a subsequent examination, was a yellow, or rather a reddish, oxide of iron, mechanically suspended in water.

I mentioned above that a part of the coal was on fire: I could not ascertain when this fact was first observed to exist; and it is not impossible that the coal may have been burning a century, or more. It is highly probable, however, that a comparatively small quantity of the coal is consumed, as the combustion must be greatly retarded by the absence of a sufficient portion of atmospheric air. A strong sulphurous fume issues from an irregular hole in the side of the hill of about 2 feet diameter. The hole appears to be only 4 or 5 feet deep, and the smoke rises into it from cracks, partly filled with loose clay. The earth is very much cracked around the hole, to the distance of 12 or 15 feet; and these cracks are from 1 to 4 inches wide. The mouth of the hole is encrusted with acicular crystals of pure sulphur. Attempts were formerly made to extinguish the fire, by turning water into this hole; and, after every attempt, there was a temporary disappearance of the smoke for several weeks; but never longer than three months. For several years, however, they have desisted from such vain attempts, and have taken advantage of the facility afforded, by the existence of this fire, for ventilating the mines, in the following manner:--They opened a passage from their present, to the old deserted, works; this they can open or shut, by means of a close door. As the old works are very near the fire, the air in them becomes very much rarified by the heat; and probably a considerable portion of it is consumed (as the principal pabulum for the combustion,) and a partial vacuum is produced. When the air in their present works, therefore, becomes impure, they open the door, and a strong current rushes into the old works; its place is again supplied with fresh air through the shafts. Previous to the adoption of this mode of ventilation, they experienced great inconvenience from carbonic acid gas; and some of the workmen had been killed by an explosion of carburetted hydrogen gas. Since this mode has been adopted, they have experienced no inconvenience at all from noxious gases. On inquiry, I was told that the substances passed through, in getting to the coal, varied in the different pits. As far, however, as I could learn by inquiry, and an examination of the heaps of rubbish, the following substances, in the order in which they stand, have been found in Heth's pits:--mould, clay, gravel, fuller's earth, sandstone, (at first extremely coarse and friable, but becoming more compact and hard, and having an appearance somewhat stratified as they descended,) gray and bluish clay slate, hard bluish sandstone, shale, or, as they term it, shiver, white micaceous sandstone, extremely hard; blue slate and shale intermixed, black slate, and then the coal. The depth of these strata differed so much in different pits, that their individual thickness could not be ascertained. Vegetable impressions are very common in the slate next the coal; and they have found the impression of a fish. Pieces of pure charcoal, in the form of sticks, or logs, are frequently found in or on the coal. In sinking one of the pits they met with a perpendicular column, 8 inches in diameter, extending through the slate into the coal; in all about 50 feet. Its surface was distinctly serrated, and at intervals of about 2 inches it appeared jointed, breaking easily at the joints. For the want of a better name I must call it a "lusus naturæ;" for it is neither clay-slate nor mica-slate, nor shale, nor sandstone; but appears to be composed of them all. Masses of a black oxide of iron are sometimes found in the slate; and from its weight and hardness the miners very properly call it ironstone. Iron pyrites are very abundant in the slate, and the heaps of rubbish are white with the sulphate of alumine; yellow ochre is found among the rubbish, but I could not ascertain its relative position with any precision. The side of the hill at the pits is covered with quartz pebbles; some of which are as transparent and beautiful as I ever saw. The country, for several miles around the pits, (i. e. as far as I have seen,) appears to be entirely destitute of rocks or pebbles, and is covered with a light sandy soil. I am unable to inform you of the number of hands employed at, or of the quantity of coal annually furnished from, these pits, as a part of my notes has, by an accident, been rendered illegible.

Thus, sir, I have endeavoured to comply with my promise of giving you an account of the coal pits.[17] In doing this, I have _only_ attempted to state facts as they existed; although I have no doubt that my imperfect acquaintance with geology has occasioned many omissions which might have been interesting. To the same cause must be attributed the use of language not always strictly scientific, and a method less exact than might have been desired. With all its imperfections, however, if you can, from the mass of facts, cull any one which may be useful or interesting, I shall be fully compensated by the pleasure of having furnished it, for any trouble I may have been at in doing so. And, if at any time I should be able to furnish you with any information relative to the mineralogy or geology of this part of the country, I hope you will let me know it.

ART. IV. _Sketch of the Geology and Mineralogy of a part of the State of Indiana, communicated in a letter to the Editor, by Mr._ W. B. STILSON.

LOUISVILLE, (Ken.) August 11, 1818.

_Dear Sir_,

I have employed a short period of leisure in passing over a portion of the state of Indiana. Among other objects, I was not wholly inattentive to the mineralogical and geological features of the country. I now, with diffidence, transmit to you the result of my inquiries.

SKETCH, &c.

The secondary formation of the state of Indiana is abundantly evident. The surface of the soil is undulating, and marked with few elevations which deserve the name of mountains. The rocks are sandstone, limestone, and clay-slate; all of which are disposed in horizontal strata. The sandstone presents nothing remarkable in its appearance. Its colours are various shades of gray and brown. The principal hills are of this formation. The principal colours of the limestone are blue and gray, and their various mingled and intermediate shades. Its secondary formation is very manifest from its almost earthy appearance. In innumerable instances, the limestone rocks contain immense quantities of imbedded shells, of great similarity in form and appearance, and having considerable resemblance, to the common escallop-shell of the ocean. Owing to the easy decomposition of these rocks, and the horizontal position of their strata, they afford many subterranean passages for water. A considerable stream, called Lost River, runs into a cave in the side of a precipitous hill; and, after a passage of 6 or 7 miles under the earth, again makes its appearance, with a large accession to its waters. The traveller's attention is continually excited by cavities in the earth, where the temporary rivulets, proceeding from rains, make a sudden exit through perpendicular perforations in the upper stratum of the rock. There are many such cavities, which do not receive any water from the surface. Some of them are many yards in diameter, forming a regular circular concave, of considerable depth towards the centre. They are vulgarly known among the inhabitants by the name of "_sink-holes_." The localities of slate are few, and present nothing uncommon.

With regard to the particular minerals. On Sand Creek, 60 miles from White River, is an interesting locality of that variety of silex, commonly called burrstone. It has been examined by several practical millers, who do not hesitate to pronounce the specimens which it affords, equal, if not superior, to the French burrs. The locality is twenty acres in extent, and appears to be inexhaustible. The mineral varies very much in its appearance; it is generally porous, and appears to have been puffed up by the escape of some gas, while it was in a state of fusion. A mass of well-raised bread gives no inadequate idea of its configuration. It produces most vivid sparks with steel. Some labourers are employed in procuring millstones from this place; and, such is the size of the siliceous rocks, that they are under no necessity of constructing them of detached masses. They form, of a single rock, millstones of five and a half feet in diameter, which are not defaced by any irregularity, or even earthy cavity. These millstones may be carried down the White, Wabash, Ohio, and Mississippi rivers, to New-Orleans, with great facility. And if they should prove as excellent as it is expected they will, this discovery will shed new lustre upon the accumulating evidence of the mineralogical resources of this republic.

Many other varieties of silex are common: rock crystal, agate, and chalcedony, are often found in the beds of rivulets. I passed a considerable distance upon the banks of a small stream, called Leather-wood creek: the bottom of the creek was covered, the whole distance, with siliceous masses, shaped like oblate spheroids, and of every size, from that of a large melon downwards. On being broken, they presented beautiful geodes of crystallized quartz, amethyst, &c. The outside was often fine chalcedony, and sometimes the interior was the same substance, in the form of balls; all these were sometimes combined, forming agates of great beauty.

Carbonate of lime, crystallized, is sometimes found; and many of the caves afford fine stalactites.

There is a large cave near Corydon, celebrated for the production of sulphate of magnesia, or Epsom salts. It has been explored for the distance of several miles. When it was first discovered, the bottom, in many places, was covered to the depth of several inches, with pure, brilliant, needle-shaped crystals of sulphate of magnesia. By some mysterious process of nature, or rather of Divine benevolence, the production of this useful salt is continually going on. This cave also produces some other salts in small quantities: nitrate of lime, nitrate of magnesia, sulphate of lime, &c.

Where the basis of the country is limestone, the waters always take up a great quantity of lime, and some of them possess great petrifying powers. I saw many specimens of petrifactions: a tuft of moss, the form perfectly preserved; leaves, bark, and branches of trees; insects, and many others.

Many of the springs are strongly impregnated with sulphur, and some of them are saturated with sulphuretted hydrogen. I found the opinion universally prevalent among the people of this state, that the first appearance of these sulphur springs was immediately subsequent to the earthquakes of 1812. They say, that then new springs, impregnated with sulphur, broke out, and the waters of some old springs, for the first time, gave indications of this mineral. A sensible farmer, who has a large sulphur-fountain, boiling up from the bottom of a river near its bank, assured me, that there was no trace of this spring until after the period to which I have alluded. He could have no interest in deceiving me; and if he did deceive me, his conduct could originate only in that love of the marvellous which is so characteristic of the human mind. He moreover assured me that the "water had been growing weaker, (to use his phrase) ever since its first appearance." I have room only to mention, among the minerals of Indiana, many varieties of clay, ochres, gypsum, alabaster, muriat of soda, (very common,) iron ore, and antimony.

ART. V. _New localities of Agate, Chalcedony, Chabasie, Stilbite, Analcime, Titanium, Prehnite, &c._

Deerfield, &c. In the account of the Mineralogy and Geology of Deerfield, by Mr. Hitchcock, in the present Number, it will be seen, that these interesting minerals (with the exception of titanium) exist in the secondary greenstone of that place. We have specimens, (through the kindness of Mr. Hitchcock,) and observe that the agates, chalcedony, analcime, and prehnite, are imbedded in the trap; the agates are in some instances very delicate in the disposition of their bands, and need nothing but polishing to make them beautiful; the same is true of the chalcedony. The chabasie and stilbite occupy cavities, and the chabasie is often distinctly crystalized in a rhomboid, so nearly approaching a cube, in the quantity of its angles, that the mistake is easily committed of supposing them to be cubes; the crystals are sometimes transparent, and the largest a quarter of an inch in diameter. Titanium is found in Leyden; it is the red oxide--very well characterized--in reddish brown crystals as large as a common goose quill,[18] and, in some instances, perfectly geniculated. It is rare to see finer specimens.

_East-Haven._ It will be observed, that the great ranges of secondary greenstone, which cut Connecticut and Massachusetts in two, terminate at New-Haven, on the one hand, and some way above Deerfield on the other. By comparing the account of the termination at New-Haven (Bruce's Journal, v. i. p. 139.) with that now published, of the termination at or near Deerfield, it will be seen that the geology and imbedded minerals are very similar. At East-Haven, (one of the branches of the greenstone of New-Haven, and within from three to four miles of the latter town,) chalcedony is often found, sometimes imbedded in the trap, (but perhaps more frequently loose among the fallen stones,) which, although in small pieces, is as perfect in its characters as the chalcedony of the Feroe Islands. It is of a delicate gray, translucent, mamillary, botryoidal, stalactitical, or impressed by crystals of quartz, which have usually fallen out; sometimes these crystals incrust the chalcedony.

Agates also are found in considerable numbers, both imbedded and loose. They usually consist of bands of chalcedony and quartz, and sometimes of the latter only, variously striped or spotted, or interlaced with jasper, carnelian, and cacholong.

The form of the imbedded agates at East-Haven is commonly ovoidal, or egg-shaped, and frequently it is conical. Some portions of pure chalcedony occur, which are shaped like a long, slender carrot or parsnip, and the situation of the latter in the ground would exactly represent that of the chalcedony or agate in the rock.

The imbedded masses are frequently altogether quartz, and then they are most commonly geodes or hollow balls lined with crystals, commonly very perfect and brilliant, although rarely large. These crystals are commonly transparent and colourless--but they exhibit also most of the varieties of colour which quartz assumes--the amethyst--the smoky--yellow, &c., and occasionally they are tipped and spotted with red jasper.

The spontaneous decay of these trap rocks causes many specimens to be found among their ruins, and many more are imbedded in the solid rock; but the industry of successive classes from the neighbouring college, issuing from Col. Gibbs's cabinet, has now made specimens more scarce.

_Woodbury._ Twenty-four miles from New-Haven, N.W.

In a geological sketch of parts of the counties of New-Haven and Litchfield, which may appear in a future Number, it will be seen that prehnite, stilbite, and agate are found at Woodbury, in the little basin of secondary greenstone which exists there; the prehnite is abundant--it is not known whether the agates are so, although it is asserted to be the fact; the stilbite was not observed to be abundant, although it was well characterized.

ART. VI. _Account of the Strata perforated by, and of the Minerals found in, the great adit to the Southampton Lead Mine. Communicated to the Editor by Mr._ AMOS EATON, _Lecturer on Geology, Botany, &c._

_To Professor Silliman._

After a laborious geological excursion along M'Clure's Springfield section, for about one hundred miles, I visited Dr. D. Hunt, at Northampton. He observed that you had expressed an opinion, that an attentive examination of all the strata constituting the walls of the artificial avenue or drift at the Southampton mines, would bring facts to knowledge, which might, in some degree, subserve the cause of geological science. I am now at the mouth of the drift, having just completed the labour which you had marked out.

I employed two miners to commence with me, at the termination of the drift, which is now extended 800 feet into the hill. We broke off large specimens, at very short intervals, throughout the whole extent of the drift. We arrived at its mouth with almost a boat load of specimens. I kept a memorandum of every thing which occurred, while under ground; and I have now arranged the specimens, before the mouth of the drift, in the same order in which they were situated in the earth.

Fatigued as I am, I will make my remarks here, in the field, lest something should hereafter escape me, which is now fresh in my recollection. Beginning with the greatest distance to which the miners have penetrated, I will set down my remarks, in fact, in reversed order.

800 feet. The rock is fine-grained gray granite, traversed by veins, lined with quartz crystals, and mostly filled with calcareous spar, often beautifully crystallized. In the same veins blue and purple fluate of lime and copper pyrites frequently occur.

790 feet. The same fine-grained granite is continued, occasionally traversed by veins lined with crystals of quartz; but containing no other minerals.

774 feet. A narrow vein of sulphuret of lead, with walls lined with crystals of quartz. The fairest cubic crystals are slightly attached to the points of the quartz crystals. Yellowish crystals of carbonate of lime are often interspersed among the lead. Sulphate of barytes occurs here also; sometimes in plates meeting at various angles, and forming chambers lined with minute crystals of quartz. Minute crystals of copper pyrites and a little fluate of lime have been found here; also fine specimens of bitter spar. The walls are very compact, fine-grained granite.

760 feet. Coarse, parti-coloured granite. The felspar is flesh-coloured and white; the quartz often bluish or greenish; the mica silvery, greenish, or purplish.

725 feet. A stratum of gray-wacke slate. Texture less firm than of the same rock at the west of Pittsfield. This stratum is very distinct, and about two feet thick.

723 feet. A stratum of serpentine rock, containing very red quartz imbedded in various directions. It is very compact, and mostly green. Here it is but about three feet thick. About ten miles south of this place, on Maclure's Springfield section, near the line between Westfield and Russel, and four miles west from Westfield Academy, I found this same stratum of very great breadth. I say the same stratum, because it is situated in the granitic hill, east of the highest ridge of granite, which is evidently a continuation of this range. Perhaps I may, hereafter, give you an account of my excursion along that section of Maclure, in which I may give you a more particular description of the Westfield serpentine.

720 feet. Coarse granite, with white and flesh-coloured felspar, black and silvery mica.

700 feet. A stratum of red mica slate, about four feet thick.

694 feet. Coarse, flesh-coloured granite. This is the handsomest granite in the whole drift. Here we find the most beautiful specimens of graphic granite, both flesh-coloured and gray.

680 feet. A stratum of Kirwan's stell-stein. That is, an aggregate of fine-grained quartz and mica, without any felspar. The quartz is mostly greenish, probably coloured by the next stratum.

670 feet. Beautiful green soapstone. Very compact, but rather softer than that kind in common use for inkstands.

666 feet. A green, granular aggregate. It seems to be made up of fine fragments of quartz, soapstone, and mica, rarely a little felspar, slightly compacted together.

_Remark._ All the strata, from the inner termination of the drift to this place, a distance of one hundred and thirty-four feet, are nearly vertical, or a very little inclined. Here they begin to approach a horizontal position.

The green aggregate continues as far as the air-well, a distance of 66 feet, with some trifling variations in the size and proportions of the aggregated fragments.

500 feet. A granulated, schistose aggregate, chiefly of quartz and mica. Though the constituents and the form of the rock correspond very nearly with mica slate, it cannot be considered as the primitive mica slate rock. It is so slightly compacted that it can scarcely be kept from falling to pieces. Its position is nearly horizontal.

480 feet. A stratum of coal, half an inch thick. This stratum may be traced, at different intervals, one hundred and eighty feet along the drift towards its mouth. It lies between the strata of the last described schistose aggregate.

400 feet. An aggregate appears, alternating with the loose schistose rock, which resembles the red sandstone, but is of a less firm texture.

From this place all the strata, east of the soapstone, occasionally appear, for the distance of about three hundred feet. This is probably on account of their undulatory forms and horizontal position. Most of the way we find the lower part of the walls to consist of a kind of semi-indurated puddingstone. Sometimes a thin stratum of fine, loose sand occurs. At 300 feet the coal stratum disappears, passing below the bottom of the drift.

The last hundred feet is chiefly gravel, which is now supported by timbers.

_Southampton, Aug. 26, 1818._

ART. VII. _On the Peat of Dutchess County--read before the Lyceum of Natural History, in New-York, by the Rev._ F. C. SCHAEFFER, _of New-York, and by him communicated to the Editor_.

In May, 1817, I brought specimens of marl and _peat_ from Dutchess county, which were taken from a fen or bog occupying an area of some acres. These fens occur frequently in the towns of Rhinebeck, Northeast, Clinton, &c. in Dutchess county. During a part of the year they are covered with water.

A pit was dug in the bog from which I procured the specimens. The order and depth of the well-defined strata which were exhibited by this excavation, I noted in my memorandum book, from which I extract the following:

After clearing away the fresh sod and recent vegetable mould, there appeared,

1. A stratum or bed of _peat_ commonly called _turf_, varying in
depth from three to four feet.

2. A stratum of peat and marl commingled; depth two feet.

3. A stratum of pure marl, from two to three feet. Below these
there was an appearance of sand and blue clay.

The first, or upper stratum, consists of _compact peat_. This substance, when first taken up, is of a dark brown colour, soft, and rather viscid. Some vegetable fibres and vacuous seeds are distributed throughout the mass. It may be moulded to any convenient form. When perfectly dry, the texture of this variety, of which there is a specimen before you, acquires a high degree of solidity. Its fracture is earthy; the colour is lighter.

I should not have offered more on this subject than the labelled specimen, had I not made a most satisfactory experiment with this kind of fuel, which may be obtained in great abundance in our own State. It is easily kindled; burns with a bright flame; yields a bluish smoke, and produces an odour similar to that which attends the combustion of gramineous substances. But this is momentary. When thoroughly kindled, it burns with less flame, yields a small proportion of blackish smoke, and sulphurous acid gas is evolved, though I cannot discover any pyrites. It burns for a long time, and emits a great body of heat. It leaves a very small proportion of light, grayish white ashes; on which I have as yet made no experiments, having this day, for the first time, paid particular attention to this substance, attracted by the unusual hardness which it acquired since it is in my possession: and not many hours have elapsed since I subjected it to combustion. The attempt succeeded so well, that I cannot refrain from expressing my opinion, that this variety of peat will answer as an excellent substitute for the best Liverpool coal.

ART. VIII. _Notices of Geology in the West-Indies._

REMARKS.

In the former Number of this work, a notice was published respecting siliceous petrifactions of wood, from Antigua. We now publish a geological sketch of the island, with notices of some other parts of the West Indies. This communication is made by a friend, with permission to publish it. It is a production of the pen of Dr. NUGENT, of St. Johns, Antigua, a gentleman of eminent scientific acquirements, who, it is hoped, will continue his laudable and able efforts to illustrate the natural history of the West-Indies.

_Memorandum concerning the Geology of Antigua, &c._

The southern and more mountainous part of the island consists of _trap_ rocks; more particularly of trap breccia and wacké-porphyry. On these beds rests a series of very peculiar stratified conglomerate rocks. These strata vary exceedingly in colour and thickness, but all dip, at a considerable angle, to the northwest. The more usual character of this rock, is that of a clayey basis, with minute particles of felspar, and small spots of _grünerde_[19] (or chlorite Baldogée.) This latter is frequently diffused over the whole, and gives it a green tinge: the colour has been thought by some to proceed from the impregnation of copper, but I am rather of opinion that is owing to manganese and iron. The conglomerate character of this rock, is derived from its having imbedded in it, or incorporated with it, numerous fragments, of all sizes, of petrified wood, chert, with and without coralline impressions, agate, jasper, amygdaloid, greenstone, hornstone, porphyry, porphyry slate, and other substances.

On this singular class of strata, reposes an extensive calcareous formation, occupying the northern and eastern part of the island, having _subordinate_ to it, and at its lowest part, where it is in contact with the conglomerate, large beds and patches of chert, which contains also a vast variety of petrified woods, several of which are of the palm tribe, with silicified shells, chiefly _cerithea_; though at the Church-hill, at St. Johns, formed of this chert, casts of bivalve and ramose madrepores are likewise found. The calcareous beds are principally of a friable marl, with blocks and layers of limestone irregularly included. In this _formation_[20] are many fossil shells, both in the calcareous and siliceous state; and there appear to be some beds, wherein is a mixture of shells of marine, and others of a fresh water, or at least a terrestrial origin. The coralline agates found in nodules and patches therein, and which may readily be distinguished from the coralline chert of the previous beds, are the most beautiful which have any where been yet noticed; and when well selected and polished, make very pleasing ornaments.

The island, as well as Barbuda, thirty miles to the northward, the Grande Terre part of Guadaloupe, at a similar distance to the southward and eastward, with several others of the West-India Islands, give proof of an extensive formation, more recent than those to which naturalists have heretofore principally confined their' attention; and which is, perhaps, contemporaneous with, if not later than, the Paris Basin, so well described by Cuvier and Brongniart.

_April 10th, 1818._ N. N.

N. B. A few specimens are sent.

REMARKS.

If the above paper be read attentively, in connexion with that in No. 1. on the petrified wood of Antigua, it will afford some very curious information to the geologist respecting these petrifactions, and must lead to interesting speculations respecting their origin, under circumstances so very peculiar, and to which we do not recollect to have heard of any parallel.

ART. IX. _Discovery of Native Crystallized Carbonate of Magnesia on Staten-Island, with a Notice of the Geology and Mineralogy of that Island, by_ JAMES PIERCE, ESQ. _of New-York, in a Letter to the Editor_.

NEW-YORK, October 19, 1818.

DEAR SIR,

I forward you a few mineral specimens characteristic of Staten-Island, including native carbonate of magnesia, in acicular crystals. I discovered this new form and locality of magnesia in examining the strata exhibited in an excavation now making, under the delusive expectation of finding gold, about three miles from the Quarantine. In descending the shaft, sunk perpendicularly in steatite, magnesite, veins of talc, and green translucent asbestus were observed at depths from six to thirty-five feet. The magnesite was found to embrace veins and cavities containing native carbonate of magnesia, in very white acicular crystals, grouped in minute fibres radiating from the sides, but not always filling the veins and cavities. The crystals were, in some instances, suspended, assuming a stalactical form. This carbonate of magnesia dissolves entirely in diluted sulphuric acid, with considerable effervescence and chemical action, producing a bitter compound, from which salts of easy solution are formed by evaporation. The magnesite in which these crystals are found, appears to be composed of carbonate of magnesia, steatite, and talc, disintegrating readily upon exposure to air and moisture: it effervesces considerably in sulphuric acid, forming a very bitter fluid that soon exhibits crystals, indicating that magnesia enters in large proportion into its constitution. Magnesite may perhaps be found at this place in quantity sufficient for a successful manufacture of Epsom salts. Small regular hexaedral crystals of mica, were noticed in steatite. Chromate of iron was sparingly diffused through the different minerals raised from various depths.

A few remarks and facts respecting the geology and mineralogy of Staten-Island, may, perhaps, give some additional interest to the specimens presented.

Staten-Island (which constitutes Richmond county) is situated about seven miles southwest of the city of New-York, extends from northeast to southwest about fifteen miles, in a straight line, with an average width of six. It exhibits a considerable diversity of surface. The eastern part is composed principally of elevated ground: a mountain chain is observed to take its rise in the vicinity of a narrow sound called the Kills, and sweep, in a semicircular form, near the eastern shore; it then ranges southwest, parallel with, and distant from Amboy Bay, about two miles, terminating near the centre of the island, and forming, with the exception of some passages, a continued chain, which, on the eastern and southern sides, is very steep, but not precipitous; it gradually declines to the west and north, and, in some places, it presents on its summit table land of considerable extent. A prominent ridge crosses the island, connecting the elevated ground of the south, with the hills of the northern part. A species of steatite, containing veins of common, indurated, and scaly talc, amianthus, and most of the varieties of asbestus, and some chromate of iron, constitutes the nucleus of the whole mountain range and elevated ground of the eastern division, stamping it as primitive. This steatite approaches, in most places, within a foot and a half of the surface, and appears in small angular loose blocks, wherever the soil has been removed. Its colour is a greenish yellow; it is brittle, very adhesive to the tongue, but little unctuous, and probably contains more alumine and less magnesia than steatites in general. Much of it decomposes when exposed to air and moisture, and forms a good mould, whenever the descent of ground permits an accumulation of earth. It is not improbable, that in most places of the Staten-Island hills, when magnesia constitutes a considerable ingredient of the rock, it will be found saturated with carbonic acid, obviating the objection to common magnesian minerals in agriculture.

The minerals observed on the surface of the northeast part of this chain of hills are, secondary greenstone, asbestoid, sandstone, granite, and gneiss, sparingly scattered in rolled masses. In addition to these rocks, in the middle and western part of the chain, a mineral of uncommon appearance is observed. It is composed principally of quartz, rough, with numerous cells of various forms, in which small siliceous crystals are generally found: the veins or plates of quartz that intersect each other, often embrace talc and oxide of iron, which, decomposing, gives some specimens the appearance of volcanic origin. Associated with this cellular ferruginous quartz, brown hæmatite is often observed; this valuable ore often yields eighty per cent. of iron of best quality; its fibres assume a variety of shapes; they were observed at Staten-Island, straight and curved, radiating from a centre, and exhibiting the stalactical, cylindrical, and botryoidal forms, often displaying a black polished surface and glistening lustre. Ferruginous minerals are abundant on the mountain for several miles. A granular oxide, called by miners shot-ore,[21] from its being principally composed of spherical grains of various sizes, was often noticed, and appears in some places in extensive beds: it is easily fused, and affords a large per centage of good iron for castings. A heavy ore, with a smooth surface and some lustre, bearing a considerable resemblance to native iron, is sometimes seen. Banks of white sand, resembling the siliceous particles of the seashore, are noticed on the mountain tops, containing masses of compact, heavy ferruginous sandstone, similar to the rocks of our alluvial seaboard. Large beds of water-worn siliceous pebbles, in no way differing from those washed by the ocean, are seen on the height of the ridge, in which excavations have been made several feet, leaving the depth of the mass uncertain. On some of the eminences, for a considerable extent, vegetation is entirely excluded by an iron-bound soil. Iron ore, imbedded in an earth coloured by, and partly composed of, oxide of iron, occupies the surface; and chalcedony and radiated quartz are sometimes observed on the primitive ridge. Prospects from many of these eminences are extensive and diversified. On one side, the ocean and a great extent of coast are in view; on the other, a rich landscape of hills and plains, the eye resting on the highland-chain and the mountains bordering Pennsylvania; the harbour, at your feet, presents a busy, ever-varying scene, and the city of New-York appears to great advantage from this point of observation.

The district between the mountain and the narrows, the thickly settled and well-cultivated plain bordering Amboy bay, and much of the western division of the island, are decidedly alluvial. Adjacent to Fort Tompkins, detached pieces of copper ore have been found. I have observed petrifactions of marine shells in rocks excavated in that neighbourhood, twenty feet from the surface, and sixty above the ocean.

The western part of the island presents moderate elevations; the soil, a good medium of sand and clay, is in general fertile; but a tract near the termination is sandy and barren. Some creeks penetrate to near the centre of the island, and are bordered by extensive salt meadows. Except at the primitive range, I have observed in no part of the island large beds of rock that can be called in place; but rolled masses of greenstone, sandstone, gneiss, granite, red jasper, and indurated clay, appear in general sparingly, but sometimes in abundance, on the surface. Lignite has been found in small quantities in the western part of the island. A chalybeate spring, of no great strength, is the only mineral water met with in Richmond county. The ponds, wells, and streams, contain a soft water, holding no lime in solution.

REMARKS.

We have already published (p. 54.) Mr. Pierce's discovery of the pulverulent carbonate of magnesia, and have pointed out its connexion with Dr. Bruce's previous discovery of the hydrate of magnesia, or pure magnesia combined with water only. Mr. Pierce has now added another important link to this chain, and future mineralogists may quote the vicinity of New-York as affording,

1. Pure magnesia, crystallized and combined with water only.

2. Carbonate of magnesia, pulverulent and white.

3. Carbonate of magnesia, in very delicate and perfectly white
acicular crystals.

We possess specimens of them all.

ART. X. _On a curious substance which accompanies the native Nitre of Kentucky and of Africa. Communicated in a letter to the Editor, from_ SAMUEL BROWN, M. D. _late of Kentucky, now of the Alabama Territory_.

REMARKS.

The scientific public were several years ago laid under obligations to Dr. Brown, for a very interesting and instructive account of the nitre caverns, &c. of Kentucky, published in the Transactions of the Philosophical Society, in Philadelphia, Vol. VI., and in Bruce's Journal, Vol. I. p. 100. The following communication arose from a conversation on that subject between Dr. Brown and the Editor.

_New-Haven, July 27, 1818._

DEAR SIR,

I have just found the passage I referred to the other day, relative to the existence of native or sandrock nitre in the interior of Southern Africa. It is in Barrow, and not in Vaillant, as I thought when I had the pleasure of conversing with you concerning it. I am much obliged to you for recalling my attention to that curious subject, as it has brought to my recollection a fact, which I believe I omitted to mention in my memoir, (viz.) the existence of a black substance in the clay under the rocks, of a bituminous appearance and smell. This I remember to have seen in a rock-house, near the Kentucky river, where very considerable quantities of sandrock nitre had been obtained. This substance was found in masses of a few ounces weight, and in the crevices of the rocks near the basis of the side walls. The smell was not wholly bituminous, but resembled that of bitumen combined with musk. I am quite unable to account for the formation of the nitre, or the production of this black substance which sometimes accompanies it, both in Africa and America. Had I seen Mr. Barrow's travels, when I noticed the bitumen, I should certainly have paid more attention to it. But perceiving no relation between the rock nitre and the masses of this substance, my examination of it was much too superficial. I do not very well understand what Mr. Barrow means by saying, that many wagon loads of animal matter lay on the _roof_ of the caverns in Africa. I saw no such matter on the _roof_ of the rock-houses in Kentucky. Certainly the caverns have been the habitations of wild beasts, and great quantities of leaves, &c. have been mixed with the debris of the superincumbent rocks, but it does not seem probable, that much animal matter could be filtrated through a roof of rock, perhaps forty or fifty feet in thickness. The subject, however, is very curious, and deserves much more attention than any of us have bestowed upon it.

_Extract from Barrow's Southern Africa, p. 291. New-York edition._

"About 12 miles to the eastward of the wells, (Hepatic wells,) in a kloof of the mountain, we found a considerable quantity of _native nitre_. It was in a cavern similar to those used by the Bosgesmans for their winter habitations, and in which they used to make the drawings above mentioned. The _under surface_ of the projecting stratum of calcareous stone, and the sides that supported it, were incrusted with a coating of _clear, white saltpetre_, that came off in flakes, from a quarter of an inch to an inch or more in thickness. The fracture resembled that of refined sugar, it burnt completely away without leaving any residuum; and if dissolved in water, and thus evaporated, crystals of _pure prismatic nitre_ were obtained. This salt, in the _same_ state, is to be met with _under_ the sandstone strata of _many_ of the mountains of Africa; but, perhaps, not in sufficient quantities to be employed as an article of export. There was also in the same cave, running down the sides of the rock, a black substance, that was apparently bituminous. The peasants called it the urine of the das. The dung of this gregarious animal was lying upon the roof of the cavern to the amount of many wagon loads. The putrid animal matter, filtrating through the rock, contributed, no doubt, to the formation of the nitre. The Hepatic wells and the native nitre rocks were in the division of Agster Sneuwberg, which joins the Tacka to the southwest."

Should I ever visit Kentucky again, I hope that I shall be able to give a better account of these caverns, which certainly are highly deserving of the attention of naturalists.

In Philadelphia you may have an opportunity of seeing some small specimens of the sandrock, containing nitre, now in the cabinet of the Philosophical Society.

BOTANY.

ART. XI. _Descriptions of species of Sponges observed on the shores of Long-Island. By_ C. S. RAFINESQUE, _Esq._

The sponges are one of the most singular productions of nature; and, even to this time, naturalists are divided in opinion respecting their real rank in the scale of organized beings. Some believe that they are animals, belonging to the class of polyps, next to the genus of _alcyonium_, while many contend that they are not animals, but plants, of the tribe of _fuci_, or marine vegetables. I am inclined to adopt this latter opinion, since in all those which I have seen, in Europe and America, no perceptible motion nor sensibility was to be discerned in any stage of their existence; and those who have acknowledged their animality, bring no stronger proof thereof than an occasional slight shrinking under the hand, and an animal smell, which are common to some marine plants.

Whatever be the truth on the subject, these doubtful opinions prove that they are of the many connecting links between animals and plants. This is not a proper place to decide this controversy; I mean merely to make known new species of this tribe of beings, which I observed last year, on the shores of Long-Island. Such a fragment will be, perhaps, the first attempt of the kind; when more species shall be known, the subject may be investigated with more certainty and accuracy.

1. _Spongia albescens_, Raf. (Whitish sponge.) Effuse, compressed, irregular, perforated, somewhat branched, unequally lobed, whitish, smooth; lobes truncated; cells porose, very minute, nearly equal; small unequal cells inside.

Found near Bath and Gravesend, in sandy bottoms. A large species, sometimes over a foot broad, of quite an irregular shape, rather flattened, about one inch thick; partly gibbose; concave now and then, and with large, irregular openings, as if large branches were anastomosed; circumference branched or lobed, very jagged, sinus obtuse, lobes elongated obtuse, truncate or flat, unequally divided. The substance is entirely of a cinereous white, outside and inside, of a soft and brittle nature, rather friable; covered outside with minute pores of an oblong or round shape, and full of small unequal cells inside.

2. _Spongia ostracina_, Raf. (Oyster sponge.) Very branched, erect, red, papillose; branches unequal, often dichotome, obtuse; cells porose, oblong, nearly equal.

It is often found on the common oyster. (_Ostrea virginica._) It rises from four to six inches, the colour is a fine red, it branches from the base; the branches are unequal, straight, cylindrical, or compressed. Substance stupose. Surface covered with small papilla and small oblong unequal pores.

3. _Spongia cespitosa_, Raf. (Bushy sponge.) Branched, cespitose, yellowish, rough, papillose; branches fasciculated, upright, unequal, flexuose, compressed, slightly anastomosed, nearly dichotome upwards; cells porose, oblong, nearly equal, margin lacerated.

Found also on the oyster, but more seldom than the foregoing; the specimens which I saw was found on the Bluepoint oysters, by Dr. Eddy. It becomes brown by drying. It rises from four to six inches, the margin of the cells or pores is torn into papillar, stiff processes, which produce a rough surface. Substance stripose. Internal cells oblong, very small.

4. _Spongia cladonia._ (Cladonian sponge.) Branched effuse, smooth, pale fulvous, stem procumbent, branches distichal, one-sided, erect, simple or divided, obtuse; cells porose, minute; some larger round.

I have found this species at Bath and at Sandy-Hook, on Sandy bottoms. Length about six inches. Stem and branches cylindrical or compressed. Substance fibrose, anastomed, branches divaricate, ascendent, semi dichotomose or simple, unequal, thicker towards the top.

5. _Spongia virgata._ (Slender sponge.) Nearly branched, smooth, fulvous, stem divided, slender, cylindrical, knobby, branches erect, slender, nearly heads acute; pores unequal, irregular, small.

A small species, three inches high, found at Oysterbay, on rocky bottoms, rare; stem with few branches, and imperfect ones, like knobs. Substance stupose. Branches round, alternate, small. Pores without any determinate shape.

ART. XII. _Memoir on the Xanthium maculatum, a New Species from the State of New-York, &c. by_ C. S. RAFINESQUE, ESQ.