Art. XIX. 1. Dr.J. W. Webster'sLectures.

INTELLIGENCE.

Art. XIX.1.Dr.J. W. Webster'sLectures.

Dr. J. W. Webster, some months since, commenced a course of Lectures in the town of Boston, on Geology and Mineralogy. Having finished his first course, he is now occupied with a second on the same subjects, and we understand receives the patronage of some of the most respectable citizens of Boston and its vicinity. He makes Geology the groundwork of his plan, and fills up by describing the metals and minerals met with in each class of rocks, after the rock has been noticed. A pretty full account is given of the coal formations, (several of which Dr. W. has visited) and of the modes of searching and boring. A view is given of the formations of Paris and the Isle of Wight, with specimens from those districts.

In the volcanic part, a description (from personal observation) is given of St. Michael's. The structure of veins; the forming and destroying effects of water; the physiognomy of the dry land and submarine; the origin of islands and coral reefs, and a view of the principal mountain ranges throughout the world conclude the course.

2.Dr. Webster's Cabinet.

Dr. Webster, having spent two or three years in Europe, in professional studies, during which time he devoted much attention to mineralogy and geology, with the ample aids afforded by the cabinets and distinguished teachers in Scotland, France, and England, has recently returned to his own country, and has brought with him a very select and considerably extensive cabinet of minerals, with which, and with American specimens, he illustrates his lectures. We understand that the collection contains some thousand specimens, and is good in the English and Scotch minerals; also in the Siberian coppers; it contains a suite of three hundred geological specimens from Freyberg, from granite to gravel. The geological part is extensive, and was increased by numerous pedestrian tours in England and Scotland; most of the geological specimens have been examined, in company with Professor Jameson. The volcanic part is good, from the extensive opportunities which Dr. Webster enjoyed in the Azores, in which, on his return to this country, he spent some time, and found much to interest him. His observations will soon be given to the public, in a work entitledRemarks on the Azores or Western Islands.

It is well known that they are volcanic, and of course afford the usual volcanic substances. The most interesting part is that occupied by the boiling fountains, in many respects similar to the Geysers of Iceland, excepting that the water is not ejected to any considerable height; but the incrustations, the sinter, and sulphur, are every way equal to any specimens which Dr. Webster saw in Sir G. Mackenzie's collection.

We are much gratified in noticing both what Dr. Webster has done and is still doing. We are persuaded that he will do much towards promoting the cultivation of American mineralogy and geology, and especially in the enlightened community in which he resides.

We cordially wish him success, and trust that it will be ensured by the patronage of the citizens of Boston.

3.Supposed identity of Copal and Amber.

A correspondent, whose paper is withheld from publication till some additional experiments can be made, conceives that copal and amber are originally the same substance, and the product of the same tree.

4.The Necronite.—(A supposed new mineral.)

Extract of a letter from Dr. H. H. Hayden of Baltimore, to the Editor, dated January 5, 1819.

"It (the necronite) occurs in a primitive marble, or limestone, which is obtained 21 miles from Baltimore, and a small distance from the York and Lancaster road. It was first noticed by myself at Washington's monument, in which this marble is principally employed.

"It occurs, for the most part, in isolated masses in the blocks, or slabs, both in an amorphous and crystallized state. It is most commonly associated with a beautiful brown mica, of the colour of titanium; small but regular crystals of sulphuret of iron, tremolite, and small prismatic crystals of titanium, which are rare. The form of the crystals is a rhomboid, approximating very much to that of the felspar, and which has inclined some to consider it as such. Also, the hexaedral prism, resembling that of the beryl. This form is rare, and has not, as yet, I believe, been found complete. Its colour is a bluish white, and clear white. Its structure much resembles felspar, being lamellar; sometimes opaque, semi-transparent and transparent, at least in moderately thin pieces. It scratches glass, carbonat of lime, and even felspar, in aslightdegree. In all our efforts, it has been found infusible, per se, or with borate of soda, and even from all the force of heat that could be excited in a smith's furnace, it came out unchanged in any degree. The acids seem to have no sensible effect upon it, either cold or hot. This is all that I can say of it at present, except that it possesses a mosthorridsmell.[44]I have since found in a marble of the same kind, but from a different quarry, and a few miles distant from the first, a quartz almost as fetid as the necronite, and likewise associated withsmallprisms of titanium.

"These substances carry with them a degree of interest in another point of view. They seem to invalidate the opinion that the fetid smell of secondary limestone, slate, &c. is derived from the decomposition of animal matter. As their gangue isdecidedlya rock of primitive formation."

Another new mineral observed by Dr. Hayden.

"Exclusive of the interest which the necronite has excited with me and several others, I have besides stumbled upon another substance, if possible still more interesting. I discovered it in an imperfect state, about 4 years since, but not until recently have I been able to find it perfect, in beautiful garnet coloured cubic crystals ¼ of an inch square or nearly. These crystals are very liable or subject to decomposition, in which state they present a perfect but spongy cube. Although they resemble the cubic zeolite, yet they have nothing of its character with them besides."

Remark.

Dr. Hayden without doubt alludes to thechabasieof the Abbé Haüy, formerly but inaccurately called the cubic zeolite; for it is really a rhomboid very nearly approaching a cube—its angles being 93° 48′, and 86° 12′.

5.Preservation of Dead Bodies.

From Thenard's Chemistry, vol. iii.Paris ed. p.713.

The author declines describing the methods of embalming commonly employed, and proceeds to describe the mode which was for the first time employed by Dr. Chaussier.

"This process consists in placing the dead body thoroughly emptied and washed, in water kept constantly saturated with corrosive sublimate. This salt gradually combines with the flesh, gives it firmness, renders it imputrescible, and incapable of being attacked by insects and worms.

"I have seen, (adds the author) a head thus prepared, which had been exposed alternately to the sun and rain during several years, without having suffered the slightest change. It was very little deformed, and easily recognized, although the flesh had become as hard as wood."

6.Matches kindling without fire.

(From Thenard's Chemistry, Vol.ii.p.525.)

This match is prepared by mingling two parts of the oxymuriate of potash and one of sulphur, which by means of a little gum is attached to a common sulphur match. This match on being dipped into, or rather slightly wet with, strong sulphuric acid, (oil of vitriol) immediately catches fire.

The author has not added the caution that the sulphur and salt should be pulverized separately; if rubbed together in a mortar, they will explode with some danger to the operator, provided the quantity be over a few grains.

Matches made upon this principle, have been for some time made and sold in this country. They are sometimes put up in little japanned cases with a small phial, from which when inverted with the mouth open, nothing will drop, and yet the match kindles on being thrust in quite to the bottom. The truth is, these bottles contain a little amianthus moistened with sulphuric acid, which thus kindles the match, but as the acid soon weakens by attracting water from the air, it is better to use a phial of the acid in the liquid state. A few drops answer the purpose, and when this is weakened, it is easily renewed.

7.Cleaveland's Mineralogy.

Our opinion of this work was fully expressed in the review of it in our first number. In the Edinburgh Review for September, 1818, this work is again reviewed, and in a manner which must gratify every friend to American science. It will be necessary to cite only a single sentence. After commending the condensed andhonestmanner in which the work is printed, (for they say, that the same matter which here fills one volume would in England have been spread over three,) the revieweradds, "We should be glad to see it reprinted exactly upon the plan of the original; and we have no doubt that it would be foundthe most useful work on mineralogy in our language." More need not be—more scarcely could be said.

8.A new Alkali.

A new alkali has recently been discovered in Sweden, by M. Arfwedson. It is found in the petalite, a mineral from Utoen, in Sweden, in a proportion not over 5 pr. ct.; also in the triphane or spodumene, in the proportion of 8 per cent. and in what is called crystallized lepidolite, in the proportion of 4 per cent. In its general properties it very nearly resembles the other alkalies. When heated in contact with platinum it acts on it. In the galvanic circuit it was decomposed "with bright scintillations, and the reduced metal being separated, afterward burnt." This metal resembles sodium. The new alkali has been called lithia. (Jour. of Science of the Roy. Inst.)

9.Ignited Platinum Wire.

In our last we mentioned the lamp without flame, the ignition of platinum wire being sustained by means of the vapour of alcohol.

Sir H. Davy has discovered that the vapour of camphor answers the same purpose: "If a piece of camphor, or a few small fragments in a heap, be placed in any convenient situation, as on a shilling, the bottom of a glass, &c. and a piece of platinum wire, either coiled or pressed up together, be heated and laid upon it, the platinum will glow as long as any camphor remains, and will frequently light it up into a flame."

Jour. Roy. Inst.

10.Red Rain.

A red rain fell in Naples, (March 14, 1818,) the common people were much alarmed, and called itbloodorfire.

An earthy powder was collected, which when dry was yellow, unctuous, and of an earthy taste; its specific gravity 2.07.

Its analysis presented silex 33—alumine 15.5—chrome 1.— iron 14.5—carbonic acid 9., and a combustible substance of a carbonaceous nature.

It is thought that this powder had not a volcanic origin, and that the presence of chrome assimilates it with meteoric stones.Ibid.

11.Gnephalium.

Professor Ives has discovered a new species of gnephalium with decurrent leaves, of which a plate and description will appear in our next number.

12.Augite.

M. Haüy has united the fassalite and the bakalite with the sahlite, a sub-species of augite. (See Mem. of the Museum of Nat. Hist. vol. 3.)

13.A New Vegetable Alkali,

Has been found by Messrs. Pelletier and Caventon in the Feve St. Ignace and the Nux Vomica. It has been named the vaucquelin, in honour of M. Vaucquelin. (Journal de Physique, for Aug. 1818.)

14.New Minerals.

Two new mineral species have been discovered, the scorrodite from Schnuburg in Saxony, and the tungstate of lead from Zinnwald in Bohemia.Ibid.

15.New Metal.

A new metal has been discovered by Berzilius, in the mines of Fahlun in Sweden, to which he has given the name of Selenium.Ibid.

16.Pure Alumine.

A large bed of this substance, perfectly pure, has been found at Argenton, Department de L'Endre.Ibid.

17.Collections of American Minerals.

We are informed that under the auspices of Col. Gibbs, a collection of American minerals by states, according to the arrangement of the minerals of the departments of France, in the cabinet of the school of mines at Paris, was begun some time since, at the rooms of the Hist. Society in New-York; and recently in the University of Cambridge. In the arrangementof the latter, he has been assisted by Dr. J. W. Webster, lecturer on mineralogy and geology in Boston.

18.C. S. Rafinesque, Esq.

We are requested to announce that a Journal of this gentleman's "Travels and Discoveries in the West, will be published this year by Cramer and Spear of Pittsburg, and that the results of his zoological and botanical labours consist in the discovery of about 15 new genera, and 180 new species of plants; about 75 new genera, and 600 new species of animals, whereof nearly 70 are new fishes, 20 new quadrupeds, 30 new reptiles, 112 new shells, 250 new fossils, &c." "He has inquired how the deep valleys have been excavated, where lakes existed, where the old falls of the Ohio were, the extent and origin of the coal region, &c."

19.Medical College of Ohio.

Extract of a letter from Cincinnati, Jan. 10th, 1819.

The legislature of the state of Ohio have just established a medical college in this city, and have by an unanimous vote passed a law incorporating the Faculty. In the act, Dr. Samuel Brown of Alabama is named as Professor of Anatomy, Dr. Daniel Drake of Cincinnati, Professor of the Institutes and Practice of Medicine, Dr. Coleman Rogers, Professor of Surgery, and Dr. Slack, Professor of Chemistry. The other Professors are to be appointed by the Faculty, and it is believed that Dr. Richardson of Lexington, Kentucky, will be called to the Obstetrical chair. Very high expectations are entertained of the importance of this institution in the west.

20.Notes on Ohio.

Caleb Atwater, Esq. of Circleville, Ohio, has issued proposals for publishing the above work, (mentioned in our last number) with a prospectus exhibiting its principal features. We doubt not it will contain valuable information concerning a very interesting portion of the United States, and every effort on the part of men of intelligence and enlarged views, to make the western and southwestern states better known, deserves, and it is believed will receive, adequate support.

21.Discovery of American Tungsten and Tellurium.

Neither of these metals, so far as we are informed, has been announced as existing in either of the Americas. It is well known to mineralogists, that tungsten is very rare, and that tellurium is found only in Transylvania.

We have now the pleasure to state that both these metals exist in the Bismuth mine, in the town of Huntington, parish of New Stratford, in Connecticut, 20 miles west of New-Haven.

During the examination of some ores, brought to us by Mr. Ephraim Lane, the proprietor of this mine, we obtained the tungsten in the state of yellow oxid, and the tellurium in the metallic state.

The tungsten is stated to be abundant in the mine; it is the ferruginous species, known to mineralogists by the name of wolfram.

We cannot yet say whether the tellurium is abundant, having obtained it from only two pieces; from these we extracted also tungsten, so that it may possibly constitute a new mineral species. Further particulars will be given in our next Number.

22.Mr. Sheldon's Application of Chesnut Wood to the Arts of Tanning and Dying.

REMARKS.

A considerable time since, we were confidentially made acquainted with the discovery detailed in the following letter. We have repeated the most important of Mr. Sheldon's experiments, both in relation to tanning and dying, and are well satisfied that the discoverer has not overrated, or erroneously estimated, the value of his own results. We are persuaded that the highlyusefularts alluded to, will derive important aid from the use of a material so abundant and cheap as chesnut wood.

To Professor Silliman.

Springfield, Mass. Feb. 27, 1819.

Dear Sir,

I send you a more particular account of the newly discovered properties of the chesnut.

This tree,Fagus Castanea, Linn. is very abundant in New-England and the middle states; and occurs in the mountainous districts, as far southward as South-Carolina, or perhaps even Georgia. It is one of the stateliest trees of the forest; scarcely less distinguished by the beauty of its foliage, than by the durability of its wood.

By repeated analyses, conducted with the minutest attention to every circumstance which could ensure accuracy, it appears, incredible as it may seem, that the chesnutwoodcontains twice as much tannin as ross'd[45]oak bark, and six-sevenths as much colouring matter (which gives a black with iron,) as logwood. I am aware that nothing could be farther from the common apprehension than such results; but the uniform success of a great variety of experiments in tanning and dying, in addition to the other kind of evidence, should satisfy the most incredulous.

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 thehigh state of oxygenizementof 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 ofhisquercitron, 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 ablackmore or less inclining to a reddishbrown. 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 theterra 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 anomenclature 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. Thesizeof 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 termstransitionandsecondary, 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 forBoa 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 isless 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 GreekΝεκρος.[45]That is, the inner bark deprived of the epidermis or outer bark, by the shaving knife.

[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 termstransitionandsecondary, 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 forBoa 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 isless 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.

REMARK.

It is indeed proved that vapour is formed from water at the lowest temperatures, but isless 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 GreekΝεκρος.

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

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