Chapter XX: Part III

3. The solution 1, diluted largely with water, deposited an abundant white precipitate, which was very heavy and rapidly subsided.

4. Alcohol and ammonia, respectively produced the same effect, only more decidedly.

5. This precipitate, evidently an oxyd of a metal, being collected on a filter and dried, exhibited the following properties.

6. Heated by the blow-pipe on charcoal, it was instantly volatilized in part, and in part decomposed, with an almost explosive effervescence; numerous ignited globules of metal appeared on the charcoal, and burned with an abundant flame of a delicate blue colour, edged occasionally with green.

7. In many trials, these results always occurred, and sometimes a peculiar odour was perceived, at first thought to be owing to arsenic, but it was incomparably feebler, and somewhat resembled that of radishes.[72]

8. Zinc, iron, and tin, plunged into separate portions of the nitro-muriatic solution, precipitated abundantly a black flocculent substance.

9. On charcoal before the blow-pipe, this substance was very combustible, with a blue flame, and was completely dissipated in the form of white oxyd, with the above smell.

10. Some of it was obtained on the charcoal in metallic globules; it was a brittle metal, white, with a tinge of red, and foliated, but not so distinctly as bismuth and antimony.

11. The filters on which the white oxyd had been deposited, burned almost with explosion, nearly as rapidly as if they had been soaked with nitrate of potash, or of ammonia, and the characteristic blue flame appeared while the burning lasted.

12. Other experiments were made upon the metal, (not the oxyd.) It gave to strong sulphuric acid, (simply by standing in it in the cold) an amethystine colour, which disappeared as the acid grew weaker, by attracting water from the air.

13. With nitric acid it formed a colourless solution, not decomposed by water.

14. It did not dissolve in muriatic acid, till a few drops of nitric acid were added.

15. The white oxyd heated with charcoal in a small coated recurved glass tube, afforded brilliant metallic globules, which rose by distillation, collected in the bend of the tube, and resembled drops of quicksilver, except that they were solid.

C. REMARK.

The above facts having induced the conclusion that the metal, thus unexpectedly discovered in the ores of tungsten, was tellurium,[73] we were led to search for external characters by which to judge what specimens contained it. The ores from Transylvania, (the only telluric ores with which we are acquainted,) bearing no analogy in appearance or composition to those before us, we were led to inquire whether the tellurium in these latter ores was _in combination_ with tungsten, or merely _in mixture_. The external characters detailed in part II, tend perhaps to fortify the latter opinion. If we mistake not, we there found a proper ore of tellurium mixed with a proper ore of tungsten, but we have also by chemical means, found tellurium where similar external characters were not apparent. Before the appearance of our next Number, we hope to obtain purer and better specimens. In the mean time we add the following facts.

1. A crystal, and a massive piece of the kind described under part I, and specimens of two varieties of those described under part II, were digested in nitro-muriatic acid.

2. Both oxyd of tungsten, and oxyd of tellurium were obtained from all of them.

3. Many specimens have been examined which have afforded tungsten only, and no tellurium.

At a convenient time, it is hoped that a more complete examination of this subject may be presented to the public.

In the mean time, we may submit to mineralogists and chemists, whether if this is not a new mineral, it is not at least a new association of two minerals before known. It has not been forgotten that gold and silver are frequently combined with tellurium: neither of them has, however, been discovered, (although sought after by proper tests) during the above trials.

_Yale College, March, 1819._

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_. With a Plate.

Few subjects have more occupied the attention of chemists, than the means of impregnating fluids with gaseous substances. The contrivances of Woulfe and Nooth, especially the former, have been almost universally used; and have gained for the inventors merited celebrity. Various improvements in Woulfe's bottles have been devised. Still I believe an apparatus replete with similar advantages, but less unwieldy, less liable to fracture; and having fewer junctures to make at each operation, has been a great desideratum with every practical chemist. It has, however, ceased to be so with me, since I contrived the apparatus which I am about to describe.

Fig. 1. represents 3 jars placed concentrically within each other, and so proportioned and situated, as to admit 2 open-necked concentric bell glasses alternately between them. The neck of the exterior bell glass is introduced into the tubulure of the receiver above, and receives the neck of the interior bell glass. Into this is inserted a trumpet-shaped tube. The two interior jars are furnished with feet F, _f_. In order to put this apparatus into operation, remove (without taking them apart) the bell glasses, receiver, and tube from the jars. Pour into the latter the fluid, to be impregnated, till it reaches the height marked by the dots. The funnel mouth, _m_, of the receiver being provided with a suitable cork soaked in wax, fasten into it firmly the beak of the retort, containing the generating materials. The bell glasses are then to be replaced in the jars, and arranged as in the figure. It must be self-evident that the gas proceeding from the retort, (if the juncture at _m_ be air tight) must press on the fluid in the innermost jar, through the trumpet-shaped tube. If not imbibed with adequate speed, it must soon press on the fluid at _a_, causing it to subside to the narrow part of the foot _f_, and thus to expose a much larger surface. If the absorption be still inadequate, a further subsidence must ensue, and the gas escaping round the brim of the interior bell glass will act on the fluid at _b_, and enlarge its surface by depressing it to the narrow part of the foot F. Should the increased pressure and more extended contact thus obtained, be still incompetent to effect a complete absorption, the excess of the gas may escape round the brim of the external bell glass into the atmosphere.

_Fig. 4._

_Fig. 5._

_Fig. 3._

_Fig. 2._

_Drawn & Engraved by Kneass, Young & Co._]

But so effectual is this process in promoting impregnation, that I have obtained strong muriatic acid in the central jar, without producing any sensible acidity in the outside one. Absorption into the retort or receiver, is prevented by not allowing as much fluid to be above the mouth of the trumpet-shaped tube, as would be competent to fill the cavity between it, and the termination of the open neck of the exterior bell glass at _t_. As this neck rises about 2 or 3 inches into the receiver, it prevents any foul matter which may condense or boil over, from getting into the jars. If practicable, it would be better that the bell glasses, and tube, and receiver, should be united together while hot, at the glass-house. If all could not be joined in this way, it would still be advantageous to unite thus the receiver, and the exterior bell glass. The interior bell and tube might then be fastened together, by grinding or luting. As yet I have only used lutings of waxed cloth, or cork. It may be proper to point out, that 3 or more concentric bell glasses, and 4 or more jars, might be used. The union of the bells, receiver, and tube once effected, it is hardly more troublesome to use 3 than 2. When the fluid in the central jar is saturated, this may be emptied and replenished from the middle jar, the latter from the external one. Then supplying the external jar anew, the process may be continued.

The other figures are to explain an apparatus on the same principle, constructed of hollow, oblong paralellopipeds, differing in length more than in breadth; so as to allow a serpentine tube to wind into the interior, and deliver gas under a vessel shaped like a T.

Fig. 2. represents a vertical section of the whole as when situated for use.[74]

Fig. 3. a vertical section of the lower vessels only.

Fig. 4. a vertical section of the covers alone.

Fig. 5. a horizontal section, or ground plan of the lower vessels. The upper vessels are so proportioned as to divide the distances between the lower ones equally.

It may be well to mention, that this apparatus, from the facility with which it may be cleaned and inspected internally, admits of being made of porcelain or stone ware.[75] I have had a cylindrical one constructed of the latter material, in which the covers are in one piece, with a tube in the centre for introducing gas. The apparatus may be made more efficacious, by drilling a series of small holes round the brims of the bell glasses or covers, so as to cause the gas, instead of passing round the brims in large bubbles, to divide itself into very small ones. By this means it will be more thoroughly intermingled with fluid.

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,[76] by_ ROBERT HARE, M. D. _Professor of Chemistry in the Medical Department of the University of Pennsylvania, and Member of several Learned Societies_.

(With an Engraving.)

I have for some time been of opinion that the principle extricated by the Voltaic pile is a compound of caloric and electricity, both being original and collateral products of Galvanic action.

The grounds of this conviction and some recent experiments confirming it, are stated in the following paper.

It is well known that heat is liberated by the Voltaic apparatus, in a manner and degree which has not been imitated by means of mechanical electricity; and that the latter, while it strikes at a greater distance, and pervades conductors with much greater speed, can with difficulty be made to effect the slightest decompositions. Wollaston, it is true, decomposed water by means of it; but the experiment was performed of necessity on a scale too minute to permit of his ascertaining, whether there were any divellent polar attractions exercised towards the atoms, as in the case of the pile. The result was probably caused by mechanical concussion, or that process by which the particles of matter are dispersed when a battery is discharged through them. The opinion of Dr. Thomson, that the fluid of the pile is in quantity greater, in intensity less, than that evolved by the machine, is very inconsistent with the experiments of the chemist above mentioned, who, before he could effect the separation of the elements of water by mechanical electricity, was obliged to confine its emission to a point imperceptible to the naked eye. If already so highly intense, wherefore the necessity of a further concentration? Besides, were the distinction made by Dr. Thomson correct, the more concentrated fluid generated by a galvanic apparatus of a great many small pairs, ought most to resemble that of the ordinary electricity; but the opposite is the case. The ignition produced by a few large Galvanic plates, where the intensity is of course low, is a result most analogous to the chemical effects of a common electrical battery. According to my view, caloric and electricity may be distinguished by the following characteristics. The former permeates all matter more or less, though with very different degrees of facility. It radiates through air, with immeasurable celerity, and distributing itself in the interior of bodies, communicates a reciprocally repellent power to atoms, but not to masses. Electricity does not radiate in or through any matter; and while it pervades some bodies, as metals, with almost infinite velocity; by others, it is so far from being conducted, that it can only pass through them by a fracture or perforation. Distributing itself over surfaces only, it causes repulsion between masses, but not between the particles of the same mass. The disposition of the last-mentioned principle to get off by neighbouring conductors, and of the other to combine with the adjoining matter, or to escape by radiation, would prevent them from being collected at the positive pole, if not in combination with each other. Were it not for a modification of their properties, consequent to some such union, they could not, in piles of thousands of pairs, be carried forward through the open air and moisture; the one so well calculated to conduct away electricity, the other so favourable to the radiation of caloric.

Pure electricity does not expand the slips of gold-leaf, between which it causes repulsion, nor does caloric cause any repulsion in the ignited masses which it expands. But as the compound fluid extricated by Galvanic action, which I shall call electro-caloric, distributes itself through the interior of bodies, and is evidently productive of corpuscular repulsion, it is in this respect more allied to caloric than to electricity.

It is true, that when common electricity causes the deflagration of metals, as by the discharge of a Leyden jar, it must be supposed to insinuate itself within them, and cause a reaction between their particles. But in this case, agreeably to my hypothesis, the electric fluid combines with the latent caloric previously existing there, and, adding to its repulsive agency, causes it to overpower cohesion.[77]

Sir Humphry Davy was so much at a loss to account for the continued ignition of wire at the poles of a Voltaic apparatus, that he considers it an objection to the materiality of heat; since the wire could not be imagined to contain sufficient caloric to keep up the emission of this principle for an unlimited time. But if we conceive an accumulation of heat to accompany that of electricity throughout the series, and to be propagated from one end to the other, the explanation of the phenomenon in question is attended by no difficulty.

The effect of the Galvanic fluid on charcoal is very consistent with my views, since, next to metals, it is one of the best conductors of electricity, and the worst of heat, and would therefore arrest the last, and allow the other to pass on. Though peculiarly liable to intense ignition, when exposed between the poles of the Voltaic apparatus, it seems to me it does not display this characteristic with common electricity. According to Sir Humphry Davy, when in connexion with the positive pole, and communicating by a platina wire with the negative pole, the latter is less heated than when, with respect to the poles, the situation of the wire and charcoal is reversed. The rationale is obvious: charcoal, being a bad conductor, and a good radiator, prevents the greater part of the heat from reaching the platina, when placed between it and the source whence the heat flows.

I had observed that as the number of pairs in Volta's pile had been extended, and their size and the energy of the interposed agents lessened, the ratio of the electrical effects to those of heat had increased; till in De Luc's column they had become completely predominant; and, on the other hand, when the pairs were made larger and fewer (as in Children's apparatus) the calorific influence had gained the ascendancy. I was led to go farther in this way, and to examine whether one pair of plates of enormous size, or what might be equivalent thereto, would not exhibit heat more purely, and demonstrate it, equally with the electric fluid, a primary product of Galvanic combinations. The elementary battery of Wollaston, though productive of an evanescent ignition, was too minute to allow him to make the observations which I had in view.

Twenty copper and twenty zinc plates, about nineteen inches square, were supported vertically in a frame, the different metals alternating at one half inch distance from each other. All the plates of the same kind of metal were soldered to a common slip, so that each set of homogeneous plates formed one continuous metallic superficies. When the copper and zinc surfaces, thus formed, are united by an intervening wire, and the whole immerged in an acid, or aceto-saline solution, in a vessel devoid of partitions, the wire becomes intensely ignited; and when hydrogen is liberated it usually takes fire, producing a very beautiful undulating, or coruscating flame.

I am confident, that if Volta and the other investigators of Galvanism, instead of multiplying the pairs of Galvanic plates, had sought to increase the effect by enlarging one pair as I have done, (for I consider the copper and zinc surfaces as reduced to two by the connexion) the apparatus would have been considered as presenting a new mode of evolving heat, as a primary effect independently of electrical influence. There is no other indication of electricity when wires from the two surfaces touch the tongue, than a slight taste, such as is excited by small pieces of zinc and silver laid on it and under it, and brought into contact with each other.

It was with a view of examining the effects of the proximity and alternation in the heterogeneous plates that I had them cut into separate squares. By having them thus divided, I have been enabled to ascertain that when all of one kind of metal are ranged on one side of the frame, and all of the other kind on the other side of it, the effect is no greater than might be expected from one pair of plates.

Volta, considering the changes consequent to his contrivance as the effect of a movement in the electric fluid, called the process electro-motion, and the plates producing it electro-motors. But the phenomena show that the plates, as I have arranged them, are calori-motors, or heat movers, and the effect calori-motion. That this is a new view of the subject, may be inferred from the following passage in Davy's Elements. That great chemist observes, "When very small conducting surfaces are used for conveying very large quantities of electricity, they become ignited; and of the different conductors that have been compared, charcoal is most easily heated by electrical discharges,[78] next iron, platina, gold, then copper, and lastly, zinc. The phenomena of electrical ignition, whether taking place in gaseous, fluid, or solid bodies, always seem to be the result of a violent exertion of the electrical attractive and repellent powers, which may be connected with motions of the particles of the substances affected. That no subtile fluid, such as the matter of heat has been imagined to be, can be discharged from these substances, in consequence of the effect of the electricity, seems probable, from the circumstance, that a wire of platina may be preserved in a state of intense ignition in vacuo, by means of the Voltaic apparatus, for an unlimited time; and such a wire cannot be supposed to contain an inexhaustible quantity of subtile matter."

But I demand where are the repellent and attractive powers to which the ignition produced by the Calorimotor can be attributed? Besides, I would beg leave respectfully to inquire of this illustrious author, whence the necessity of considering the heat evolved under the circumstances alluded to as the effect of the electrical fluid; or why we may not as well suppose the latter to be excited by the heat? It is evident, as he observes, that a wire cannot be supposed to contain an inexhaustible supply of matter however subtile; but wherefore may not one kind of subtile matter be supplied to it from the apparatus as well as another; especially, when to suppose such a supply is quite as inconsistent with the characteristics of pure electricity, as with those of pure caloric?

It is evident from Mr. Children's paper in the Annals of Philosophy, on the subject of his large apparatus, that the ignition produced by it was ascribed to electrical excitement.

For the purpose of ascertaining the necessity of the alternation and proximity of the copper and zinc plates, it has been mentioned that distinct square sheets were employed. The experiments have since been repeated and found to succeed by Dr. Patterson and Mr. Lukens, by means of two continuous sheets, one of zinc, the other of copper, wound into two concentric coils or spirals. This, though the circumstance was not known to them, was the form I had myself proposed to adopt, and had suggested as convenient for a Galvanic apparatus to several friends at the beginning of the winter;[79] though the consideration above stated induced me to prefer for a first experiment a more manageable arrangement.

Since writing the above, I find that when, in the apparatus of twenty copper and twenty zinc plates, ten copper plates on one side are connected with ten zinc on the other, and a communication made between the remaining twenty by a piece of iron wire, about the eighth of an inch in diameter, the wire enters into a vivid state of combustion on the immersion of the plates. Platina wire equal to No. 18 (the largest I had at hand) is rapidly fused if substituted for the iron.

This arrangement is equivalent to a battery of two large Galvanic pairs; excepting that there is no insulation, all the plates being plunged in one vessel. I have usually separated the pairs by a board, extending across the frame merely.

Indeed, when the forty plates were successively associated in pairs, of copper and zinc, though suspended in a fluid held in a common recipient without partitions; there was considerable intensity of Galvanic action. This shows that, independently of any power of conducting electricity, there is some movement in the solvent fluid which tends to carry forward the Galvanic principle from the copper to the zinc end of the series. I infer that electro-caloric is communicated in this case by circulation, and that in non-elastic fluids the same difficulty exists as to its retrocession from the positive to the negative end of the series, as is found in the downward passage of caloric through them.

It ought to be mentioned, that the connecting wire should be placed between the heterogeneous surfaces before their immersion, as the most intense ignition takes place immediately afterward. If the connexion be made after the plates are immersed, the effect is much less powerful; and sometimes after two or three immersions the apparatus loses its power, though the action of the solvent should become in the interim much more violent. Without any change in the latter, after the plates have been for some time suspended in the air, they regain their efficacy. I had observed in a Galvanic pile of three hundred pairs of two inches square, a like consequence resulting from a simultaneous immersion of the whole.[80] The bars holding the plates were balanced by weights, as window-sashes are, so that all the plates could be very quickly dipped. A platina wire, No. 18, was fused into a globule, while the evolution of potassium was demonstrated by a rose-coloured flame arising from some potash which had been placed between the poles. The heat however diminished in a few seconds, though the greater extrication of hydrogen from the plates indicated a more intense chemical action.

Agreeably to an observation of Dr. Patterson, electrical excitement may be detected in the apparatus by the condensing electroscope; but this is no more than what Volta observed to be the consequence of the contact of heterogeneous metals.

The thinnest piece of charcoal intercepts the calorific agent, whatever it may be. In order to ascertain this, the inside of a hollow brass cylinder, having the internal diameter two inches, and the outside of another smaller cylinder of the same substance, were made conical and correspondent, so that the greater would contain the less, and leave an interstice of about one-sixteenth of an inch between them. This interstice was filled with wood, by plugging the larger cylinder with this material, and excavating the plug till it would permit the smaller brass cylinder to be driven in. The excavation and the fitting of the cylinders was performed accurately by means of a turning lathe. The wood in the interstice was then charred by exposing the whole covered by sand in a crucible to a red heat. The charcoal, notwithstanding the shrinkage consequent to the fire, was brought into complete contact with the inclosing metallic surfaces by pressing the interior cylinder further into the exterior one.

Thus prepared, the interior cylinder being made to touch one of the Galvanic surfaces, a wire brought from the other Galvanic surface into contact with the outside cylinder, was not affected in the least, though the slightest touch of the interior one caused ignition. The contact of the charcoal with the containing metals probably took place throughout a superficies of four square inches, and the wire was not much more than the hundredth part of an inch thick, so that unless it were to conduct electricity about forty thousand times better than the charcoal, it ought to have been heated; if the calorific influence of this apparatus result from electrical excitement.

I am led finally to suppose, that the contact of dissimilar metals, when subjected to the action of solvents, causes a movement in caloric as well as in the electric fluid, and that the phenomena of Galvanism, the unlimited evolution of heat by friction, the extrication of gaseous matter without the production of cold, might all be explained by supposing a combination between the fluids of heat and electricity. We find scarcely any two kinds of ponderable matter which do not exercise more or less affinity towards each other. Moreover, imponderable particles are supposed highly attractive of ponderable ones. Why then should we not infer the existence of similar affinities between imponderable particles reciprocally? That a peculiar combination between heat and light exists in the solar beams, is evident from their not imparting warmth to a lens through which they may pass, as do those of our culinary fires.

Under this view of the case, the action of the poles in Galvanic decomposition is one of complex affinity. The particles of compounds are attracted to the different wires agreeably to their susceptibilities to the positive and negative attraction, and the caloric leaving the electric fluid with which it had been combined, unites with them at the moment that their electric state is neutralized.

As an exciting fluid, I have usually employed a solution of one part sulphuric acid, and two parts muriate of soda with seventy of water; but, to my surprise, I have produced nearly a white heat by an alkaline solution barely sensible to the taste.

For the display of the heat effects, the addition of manganese, red lead, or the nitrates, is advantageous.

The rationale is obvious. The oxygen of these substances prevents the liberation of the gaseous hydrogen, which would carry off the caloric. Adding to diluted muriatic acid, while acting on zinc, enough red lead to prevent effervescence, the temperature rose from 70 to 110 Fahrenheit.

The power of the calorimotor is much increased by having the communication between the different sheets formed by very large strips or masses of metal. Observing this, I rendered the sheets of copper shorter by half an inch, for a distance of four inches of their edges, where the communication was to be made between the zinc sheets; and, vice versa, the zinc was made in the same way shorter than the copper sheets where these were to communicate with each other. The edges of the shortened sheets being defended by strips of wood, tin was cast on the intermediate protruding edges of the longer ones, so as to embrace a portion of each equal to about one quarter of an inch by four inches. On one side, the tin was made to run completely across, connecting at the same time ten copper and ten zinc sheets. On the other side there was an interstice of above a quarter of an inch left between the stratum of tin embracing the copper, and that embracing the zinc plates. On each of the approaching terminations of the connecting tin strata was soldered a kind of forceps, formed of a bent piece of sheet brass, furnished with a screw for pressing the jaws together. The distance between the different forceps was about two inches. The advantage of a very close contact was made very evident by the action of the screws; the relaxation or increase of pressure on the connecting wire by turning them being productive of a correspondent change in the intensity of ignition.

It now remains to state, that by means of iron ignited in this apparatus, a fixed alkali may be decomposed extemporaneously.[81] If a connecting iron wire, while in combustion, be touched by the hydrate of potash, the evolution of potassium is demonstrated by a rose-coloured flame. The alkali may be applied to the wire in small pieces in a flat hook of sheet iron. But the best mode of application is by means of a tray made by doubling a slip of sheet iron at the ends, and leaving a receptacle in the centre, in which the potash may be placed covered with filings. This tray being substituted for the connecting wire, as soon as the immersion of the apparatus causes the metal to burn, the rose-coloured flame appears, and if the residuum left in the sheet iron be afterward thrown into water, an effervescence sometimes ensues.

I have ascertained that an iron heated to combustion, by a blacksmith's forge fire, will cause the decomposition of the hydrate of potash.

The dimensions of the Calorimotor may be much reduced without proportionably diminishing the effect. I have one of sixty plates within a cubic foot, which burns off No. 16, iron wire. A good workman could get 120 plates of a foot square within a hollow cube of a size no larger. But the inflammation of the hydrogen which gives so much splendour to the experiment, can only be exhibited advantageously on a large scale.

_Fig. 1._

_Fig. 2._

_Fig. 3._

_Fig. 4._

_Drawn & Engraved by Kneass, Young & Co._]

EXPLANATION OF THE PLATE.

A _a_, Fig. 1st, two cubical vessels, 20 inches square, inside. _b b b b_ a frame of wood containing 20 sheets of copper, and 20 sheets of zinc, alternating with each other, and about half an inch apart. T T _t t_ masses of tin cast over the protruding edges of the sheets which are to communicate with each other. Fig. 2, represents the mode in which the junction between the various sheets and tin masses is effected. Between the letters _z z_, the zinc only is in contact with the tin masses. Between _c c_ the copper alone touches. It may be observed, that, at the back of the frame, ten sheets of copper between _c c_, and ten sheets of zinc between _z z_, are made to communicate, by a common mass of tin extending the whole length of the frame, between T T: but in front, as in fig. 1, there is an interstice between the mass of tin connecting the ten copper sheets, and that connecting the ten zinc sheets. The screw forceps, appertaining to each of the tin masses, may be seen on either side of the interstice: and likewise a wire for ignition held between them. The application of the rope, pulley, and weights, is obvious. The swivel at S permits the frame to be swung round and lowered into water in the vessel _a_, to wash off the acid, which, after immersion in the other vessel, might continue to act on the sheets, encrusting them with oxide. Between _p p_ there is a wooden partition which is not necessary, though it may be beneficial.

Fig. 3, represents an apparatus alluded to, page 419. It consists of a couronne des tasses, reduced to a form no less compact than that of the trough. Hollow parallelopipeds of glass are substituted for tumblers or cells. The plates are suspended to bars counterpoised like window-sashes.

The advantages are as follows. The material is one of the best non-conductors, is easily cleansed, and is the most impervious to solvents. The fracture of one of the cups is easily remedied by a supernumerary. They may be procured (as in the United States) where porcelain cannot be had. The shock from 300 pairs is such as few will take a second time. Some of the effects have already been stated.[82]

At Fig. 4, one of the hollow glass parallelopipeds on an enlarged scale is represented.

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_.

In the circle ABCD let AB and BC denote any two arcs contiguous to each other. Draw their limiting diameters A_a_, C_c_; their sines B_x_, B_y_; and join _x_, _y_. Then will _xy_ = sine of (AB + BC): for if upon OB as a diameter we describe a circle, it will manifestly pass through the points _x_ and _y_, (since the angles O_x_B, O_y_B are right, see Euc. 31. 3.) therefore O_x_B_y_ is a quadrilateral inscribed in a circle described on OB as a diameter, and the angle _y_O_x_ at the circumference stands upon an arc whose chord is _xy_. Again, if from _a_ we draw _ad_ perpendicular to C_c_, it will be the sine of the arc _ac_ (= AB + BC). If now we describe a circle on _a_O as diameter, it will pass through _d_, (see Euc. 31. 3.) therefore _ad_ is the chord of an arc on which the angle _a_O_c_ stands in the circle described on _a_O. But in equal circles the chords of arcs on which equal angles at the centres or circumferences stand are equal; (see Euc. 26. and 29. 3.) hence _xy_ = _ad_ = sin(AB + BC). Now sine O_x_B_y_ is a quadrilateral inscribed in the circle described on OB as diameter, we shall have (Euc. D. 6.)

OB · xy = Bx · Oy + By · Ox = sinAB · cosCB + sinCB · cosAB.

If OB be denoted by r, we shall have xy, or

sin(AB + BC) = (sinAB · cosCB + sinCB · cosAB)/r.

If AB = A, BC = B, and the radius r = 1,

sin(A + B) = sinA · CosB + sinB · cosA;

which is the known formula for the sine of the sum of two arcs, to the radius 1.

Again, if through O we draw the diameter DE perpendicular to A_a_, then will DC be the complement of (AB + BC). Draw C_p_, the sine of DC = cos(AB + BC). Through B draw the diameter B_b_; from _b_, draw the sines _bz_, _br_, of the arcs _bc_, _b_E respectively, and join _z_, _r_. Then by describing two circles, one on _b_O as diameter, the other on OC, it may be proved as before that the circle described on _b_O passes through the points _z_ and _r_, and that the circle described on CO passes through _p_: and hence, by the same reasoning as before, _zr_ = C_p_ = cos(AB + BC). Now O_bzr_ being a quadrilateral inscribed in the circle described on _b_O, we have (by the prop. before cited)

bO · zr + Or · bz = br · Oz;

and hence bO · zr = br · Oz - Or · bz.

But _br_ = sine arc _b_E = sine arc BD; and since BD is the complement of AB, _br_ = cosAB. In like manner O_z_ = cosBC, O_r_ = sinAB, and _bz_ = sinBC; hence by substitution,

bO · zr = cosAB · cosBC - sinAB · sinBC.

By using the same notation as before, we have

cos(A + B) = (cosA · cosB - sinA · sinB)/r
= (if r = 1) cosA · cosB - sinA · sinB,

which is the known formula for the cosine of the sum of two arcs.

The same construction will answer for the two remaining cases: for if we suppose that _b_E and _bc_ are two arcs, then will _c_E be their difference, and _zr_ the sine of _c_E, as proved above; hence

zr (= sin(bE - bc)) = (br · Oz - Or · bz)/bO.

But _br_ = sin_b_E, and O_r_ = its cosine; and _bz_ = sine _bc_, and O_z_ = its cos., hence if _b_E be denoted by _a_, _bc_ by _b_, and O_b_ as before, then will

sin(a - b) = (sina · cosb - sinb · cosa)/r
= (if r = 1) sina · cosb - sinb · cosa.

Again, AB + BC is the complement of DC or _c_E; hence by the first part of the above investigation,

xy = sin(AB + BC) = coscE:

but xy or sin(A + B) = cos(a - b) = (sinA · cosB + sinB · cosA)/r;

and as sinA or AB = cosBD = cos_b_E, O_x_ = cosA or AB = sinBD = sin_b_E, B_y_ = _bz_ = sin_bc_, and O_y_ = O_z_ = cos_bc_, we shall have, by substitution,

cos(a - b) = (cosa · cosb + sina · sinb)/r,
= (if r = 1) cosa · cosb + sina · sinb.

From what has been said it appears, that if A and B be any two arcs, of which A is the greatest, then

Sin(A ± B) = (sinA · cosB ± sinB · cosA)/r;

Cos(A ± B) = (cosA · cosB ∓ sinA · sinB)/r.

When the radius _r_ is supposed = 1, the denominators in these formulæ disappear. In the latter, A and B are used for _a_ and _b_, for the sake of homogeneity. The propriety of this is manifest; for as _a_ and _b_ denote two indefinite arcs, the same reasoning will apply to A and B, as to _a_ and _b_, the first being supposed in each case the greatest.

* * * * *

The following Diophantine Problem was proposed for solution some months ago in a Periodical Journal, which has since been discontinued. To those who are interested in speculations of this nature, we presume that the following solution, forwarded by Professor STRONG, of Hamilton College, will not be unacceptable.

PROBLEM.

_To find three positive rational Numbers, x, y, and z, such that x^2 - y, x^2 - z, y^2 - x, and y^2 - z may all be squares._

Assume x - ay for the root of the square x^2 - y:

then x^2 - y = (x - ay)^2, whence x = (a^2y + 1)/2a.

In like manner, by assuming x - bz for the root of the square x^2 - z,

we find z = (2bx - 1)/b^2.

But y^2 - x = y^2 - (a^2y + 1)/2a, (since x = (a^2y + 1)/2a);

and as this is to be made a square, assume y - c((a^2y + 1)/2a)
for its root; whence, by proceeding as before, we find

y = (2a + c^2)/(4ca - a^2c^2).

But x = (a^2y + 1)/2a = (by substituting for y its value)

(a^2 + 2c)/(4ca - c^2a^2).

Again z = (2bx - 1)/b^2 = (by substituting for x its value)

[2b((a^2 + 2c)/(4ca - c^2a^2)) - 1]/b^2; hence

y^2 - z = [((2a + c^2)/(4ca - c^2a^2))^2 × b^2
- 2b((a^2 + 2c)/(4ca - c^2a^2)) + 1]/b^2

(by substituting for y and z their values;) and as this also is
to be made a square, assume for its root (be - 1)/b. Then we shall have

((2a + c^2)/(4ca - c^2a^2))^2 × b^2
- 2b((a^2 + 2c)/(4ca - c^2a^2)) + 1 = (be - 1)^2;

from which, by reduction,

b = 2 × [e(4ca - c^2a^2)^2 - (a^2 + 2c)(4ca - c^2a^2)]
/ [e^2(4ca - c^2a^2)^2 - (2a + c^2)^2].

Hence the values of the required numbers are as follows:

z = (2bx - 1)/b^2,
(in which the value of b is to be found from the last equation,)

x = (a^2 + 2c)/(4ca - c^2a^2), and

y = (2a + c^2)/(4ca - c^2a^2).

The numbers _a_, _c_, and _e_, are to be so assumed that _x_, _y_, and _z_ may come out positive. If _a_ = 1, _c_ = 2, and _e_ = 2, then will _x_ = 5/4, _y_ = 3/2, and _z_ = 14/9, which numbers will be found upon trial to satisfy the question. It may also be observed that _c_ and _a_ being positive, _ca_ must not exceed 4; but the form of the above expressions for _x_, _y_, _z_, will be sufficient to direct us how _a_, _c_, and _e_, are to be assumed.

MISCELLANEOUS.

ART. XXI. _An Account of several Ancient Mounds, and of two Caves, in East Tennessee, by_ MR. JOHN HENRY KAIN, _of Knoxville_.

(Communicated for the American Journal of Science, &c.)

_Mounds._

On the plantation of Mr. John Kain of Knox county, near the north bank of the Holston River, 5 miles above its junction with the French Broad, is a curious collection of mounds of earth, evidently the work of art, but of an almost antediluvian antiquity, if we may form any conjecture of their age, from that of the forest which grows around and upon them. They are about half a dozen in number, and arise on about half an acre of level ground without any seeming regularity. They are pyramidal in their shape, or rather sections of pyramids, whose bases are from 10 to 30 paces in diameter. The largest one in this group rises about 10 feet above the level ground, and is remarkably regular in its figure. A perpendicular section of this mound was made about a year since, but no important discovery was made. It was found to consist of the surface thrown up, and contained a good deal of ashes and charcoal.

This group of mounds is surrounded by a ditch, which can be distinctly traced on three sides, and enclosing besides the mounds, several acres of ground. It is like the mounds covered with trees, which grow in it and about it. At every angle of this ditch, it sweeps out into a semicircle, and it appears in many respects well calculated for defence.

There are many other mounds of the same form in Tennessee. At the junction of the French Broad with the Holston, there is one in which human bones are said to have been found. Farther up French Broad, near Newport, is a very large mound. It reposes on a very level and extensive plain, and is itself the largest I ever saw. It is thirty feet high, and its base covers half an acre of ground. As it ascends from its base, there is a slight inclination from a perpendicular on all sides, and the upper surface is as level as the rest is regular. From the great size of this mound, its commanding situation, and the mystery which veils its history, it is a most interesting spot of ground. There are many other mounds of this description in the State of Tennessee, but I have not visited them.

Though not immediately connected with this subject, I take the liberty to subjoin an account of a remarkable cave or grotto, in a bluff of limestone, on the south bank of the Holston River, opposite the mounds first described. The bluff is perhaps 100 feet high and 50 wide. The grotto is a large natural excavation of the rock, 60 feet high and 30 feet wide. It is very irregular, and to the very top bears marks of the attrition of waves. The river to have been so high, must have covered the valley through which it now winds its quiet way. The excavation gradually diminishes in size as you proceed backward, till at 100 feet from the entrance, it terminates. A remarkable projection of the rock divides the back part into two stories. This grotto, whose walls are hung with ivy, and the bluff crowned with cedars, and surrounded by an aged forest, on which the vine clambers most luxuriantly, viewed from the river which winds slowly around it, and reflects its image, is more than beautiful: it is even venerable. But what renders it most interesting to many visitors, is a number of rude paintings, which were, as tradition reports, left on it by the Cherokee Indians. These Indians are known to have made this cave a resting-place, as they passed up and down the River Holston. These paintings are still distinct, though they have faded somewhat within my remembrance. They consist of representations of the sun and moon, of a man, of birds, fishes, &c. They are all of red paint, and resemble in this respect, the paintings on Paint Rock near the warm springs.

Much has been said of the objects of curiosity in the country north of us; and I took the liberty to describe some of them in my preceding communication. Indeed we may say, without danger of exaggeration, that the range of Alleghany Mountains presents a variety of the most curious features, and many objects of beauty and sublimity. I have noticed a few of the most prominent, but "the half is not told."

_Extract of a Letter, &c._

_Knoxville, Nov. 24, 1818._

I was on a visit to a friend a few days since, about 30 miles to the north of this, and was invited by him to visit an interesting curiosity in the neighbourhood. We crossed the Clynch River where it is much confined by mountains, and banks as high as mountains. Our guide conducted us to the foot of a steep declivity, where we left our horses, and with some difficulty ascended about 70 yards. Here we came to the mouth of a cave which had been stopped up by a stone wall. The wall was made of limestone and mortar, which is now harder than the stone itself. It is, without a doubt, artificial, for besides the evidence afforded by its structure, it contains bones and animal remains.

What was this wall built for? There was a tradition among the inhabitants that it contained money, and they were much disappointed on opening it, not to find any. Like other caves, it contains a variety of calcareous concretions, and I obtained some fine specimens of brown spar, which I will take the first opportunity to send you.

I remain your Friend,

JOHN H. KAIN.

N. B. This wall is 10 feet thick.

_For the American Journal of Science, &c._

BENJAMIN SILLIMAN, ESQ.

_Dear Sir_,

Should you think the facts detailed in the following statement worthy of publication, you are at liberty to publish them. The knowledge of the first, I derived in the year 1802, from a gentleman and a lady, both inhabitants of the town where the person whose case is detailed, lived: of the third in 1802, from the same lady: and of the second in 1802, from a lady, a near relative of Mrs. S. When the facts were communicated to me, I immediately committed them to writing, and to avoid mistakes, read what I had written to the persons communicating them.

I am very respectfully,

Your Friend, and obedient Servant,

BENJAMIN W. DWIGHT.

ART. XXII. _Facts illustrative of the Powers and Operations of the Human Mind in a Diseased State._

1. Some years ago a farmer of fair character, who resided in an interior town in New England, sold his farm, with an intention of purchasing another in a different town. His mind was naturally of a melancholy cast. Shortly after the sale of his farm, he was induced to believe that he had sold it for less than its value. This persuasion brought on dissatisfaction, and eventually a considerable degree of melancholy. In this situation, one of his neighbours engaged him to enclose a lot of land, with a post and rail fence, which he was to commence making the next day. At the time appointed he went into the field, and began with a beetle and wedges to split the timber, out of which the posts and rails were to be prepared. On finishing his day's work, he put his beetle and wedges into a hollow tree, and went home. Two of his sons had been at work through the day in a distant part of the same field. On his return, he directed them to get up early the next morning, to assist him in making the fence. In the course of the evening he became delirious, and continued in this situation several years; when his mental powers were suddenly restored. The first question which he asked after the return of his reason, was, whether his sons had brought in the beetle and wedges. He appeared to be wholly unconscious of the time that had elapsed from the commencement of his delirium. His sons, apprehensive that any explanations might induce a return of his disease, simply replied that they had been unable to find them. He immediately arose from his bed, went into the field where he had been at work a number of years before, and found the wedges, and the rings of the beetle, where he had left them, the beetle itself having mouldered away. During his delirium, his mind had not been occupied with those subjects with which it was conversant in health.

2. Mrs. S., an intelligent lady, belonging to a respectable family in the State of New-York, some years ago undertook a piece of fine needlework. She devoted her time to it almost constantly for a number of days. Before she had completed it, she became suddenly delirious. In this state, without experiencing any material abatement of her disease, she continued for about seven years; when her reason was suddenly restored. One of the first questions which she asked after her reason returned, related to her needlework. It is a remarkable fact, that during the long continuance of her delirium she said nothing, so far as was recollected, about her needlework, nor concerning any such subjects as usually occupied her attention when in health.

3. A lady in New England, of a respectable family, was for a considerable period subject to paroxysms of delirium. These paroxysms came on instantaneously, and after continuing an indefinite time, went off as suddenly; leaving her mind perfectly rational. It often happened that when she was engaged in rational and interesting conversation, she would stop short in the midst of it, become in a moment entirely delirious, and commence a conversation on some other subject, not having the remotest connexion with the previous one, nor would she advert to that during her delirium. When she became rational again, she would pursue the same conversation in which she had been engaged during the lucid interval, beginning where she had left off. To such a degree was this carried, that she would complete an unfinished story or sentence, or even an unfinished word. When her next delirious paroxysm came on, she would continue the conversation which she had been pursuing in her preceding paroxysm; so that she appeared as a person might be supposed to do, who had two souls, each occasionally dormant, and occasionally active, and utterly ignorant of what the other was doing.

INTELLIGENCE.

ART. XXIII. 1. _Discovery of American Cinnabar and Native Lead._

_Extract of a letter from Dr. Comstock of Hartford, to the Editor._

SIR,

In answer to your inquiry concerning the discovery of sulphuret of mercury and native lead in this country, I send you the following summary of a letter I received from B. F. Stickney, Esq. Indian agent, dated Fort Wayne, Dec. 1, 1818.

Mr. Stickney states, that the situation of Fort Wayne, and the country surrounding, is a high level, probably about 800 feet above the sea. From this place the water-courses divide and take different directions, on the one hand falling into the Gulf of Mexico, and on the other into the Bay of St. Lawrence. The whole country is of secondary formation, chiefly calcareous and aluminous.

Bitumen and sulphur are every where to be found, and as usual, accompanied by the metals.

In speaking of the cinnabar, his words are, "I have found a black and garnet-coloured sand, in great abundance on the shores of the Lakes Erie and Michigan, this is a sulphuret of mercury, and yields about sixty per cent. It is so easy to be obtained, and in so convenient a form for distillation, that it must become an important article of commerce."

The native lead was found on the Anglaize River, at a considerable distance from the fort.

Of this he says, "metallic lead is so interspersed with galena, as to prove incontestably the existence of native lead."

Respectfully,

Your obedient Servant,

J. L. COMSTOCK.

_Hartford, Conn. Feb. 17, 1819._

_Benjamin Silliman, M. D., &c._

2. _Theoretical views of Professor Hare of Philadelphia._

We are authorized to mention, that Dr. Robert Hare has taught in his lectures during the last eighteen months, that acid properties never appearing in the absence of water, this fluid or its elements are most entitled to be considered as the acidifying principle: but that probably it does not exist in acids as water, but is decomposed when added to them, the particles of hydrogen and oxygen by their different polarities taking opposite sides of those composing the base. The extrication of hydrogen by the action of diluted sulphuric acid on iron or zinc, being the consequence of a previous, not simultaneous decomposition of water. Hence when sulphuric or nitric acids are so concentrated as to char or ignite, they are not acids really.

3. _New Work on Chemistry._

Dr. John Gorham of Boston, Professor of Chemistry in Harvard University, &c. has published the first volume of his Elements of Chemical Science. The work will be comprised in two volumes, and its completion will be anticipated with interest by the scientific public.

4. _Botanical._

Dr. Romer of Zurich, has begun, since 1815, to publish a new edition of the Systema Vegetabilium of Linnæus; he proceeds in its publication; it will form several volumes.

Robert Brown of London, is endeavouring to group the natural orders of plants into natural classes, or rather into larger natural orders, with determinate characters: he has communicated some parts of his labour to the botanists of Paris. He has been the first to employ as a new character in the distinction of natural orders, the estivation of flowers, or the manner in which they are folded in the buds.

C. S. Rafinesque, in his Analysis of Nature, has adopted a new practice, that of giving single substantive Latin names to the natural orders and families of plants.

Mirbel has proposed a new nomenclature of fruits in his Elements of Botany.

Decandolle, after publishing the principles of the science in his Theory of Botany, has begun to undertake a general species plantarum, according to the natural classification.

Three splendid Floras of the south of Europe have been undertaken. 1. Flora Græca, by Sibthorp and Smith in England. 2. Flora Lusitanica, by Link and Hoffmansegg in Germany. 3. Flora Nepolitana, by Tenore in Naples. They are very expensive works, and are not yet terminated. _Received in January, 1819._

5. _Staurotide._

Extract of a letter to the Editor, from John Torrey, M.D., of
New-York.

"Mr. Pierce and myself lately found staurotide on the island of New-York. It occurs in considerable quantity in a rock of _mica slate_, on the banks of the Hudson, about three and a half miles from the city. The crystals very seldom form the perfect cross, though many were found, intersecting each other imperfectly at angles of 60°. Several single crystals were obtained exceedingly perfect. They were short 4-sided prisms, with the acute lateral edges truncated at each extremity on the two solid angles of the most obtuse lateral edges, forming diedral terminations at each extremity of the prism. The faces of these terminations were inclined to each other at an angle of 67° and a few minutes. The annexed figure shows the form of the crystal."

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.

The following minerals, found in the region above named, were either omitted in the former list, or have been noticed since that was made out.

_Bog-iron Ore._ In Greenfield and Warwick.

_Hornstone._ Rare; in Deerfield and Conway.

_Silicious Slate._ In rolled pieces, on the banks of Deerfield
river; not abundant.

_Basanite_, or _Lydian Stone_. Same locality.

_Augite._ In an aggregate of greenstone, quartz, and calcareous
spar, in the greenstone range, Deerfield. Colour black, and the
crystals usually imperfect, or broken.

_Staurotide._ In mica slate, Northfield, one mile east of the
village, on the turnpike to Boston. The crystals observed were
six-sided prisms. The same rock contains reddish garnets.

THE LEVERETT RANGE OF GRANITE.

This name is given to a granite range that emerges from the puddingstone near the centre of Amherst, and extends northerly, with some interruption, nearly thirty miles, through Leverett and Montague to Northfield. And, indeed, there is some reason to suppose that it again appears to the north of Northfield. The range is widest in Leverett, where its breadth is more than a mile. It is noticed in the "Remarks," No. 2, Art. I, of this Journal, and may be seen on the section accompanying that communication. But on further examination it has been found to be more extensive than was supposed. The texture of the rock is coarse. Plates of mica, 3 or 4 inches across, are common in it; and one specimen of a beautiful blue feldspar, the fragment only of a crystal, measured in one direction 8 inches.

Two circumstances in this range give it an interest in the eye of a geologist. The one is its proximity to sandstone and puddingstone; and the other, its small elevation in comparison with the surrounding rocks of later formations. In some places no other rock could be found lying between the granite and puddingstone; though the soil prevented my observing whether there is an actual contact. But in general there is a stratum of mica slate a few rods wide between these rocks, and not unfrequently gneiss lies between the mica slate and granite.

Standing on this range in Leverett, you have on the west, at about 100 rods distant, a precipitous mountain of sandstone and puddingstone, five or six hundred feet higher than the granite. On the east, a mile or two distant, a mountain of sienite gradually rises to a still greater height than the puddingstone; and on the southwest, at nearly the same distance, you can see an alluvial formation. In general this granite does not rise so high as the adjacent rocks, whether secondary or primitive.

VEINS OF ORE IN THIS GRANITE.

1. _Of Galena in Leverett._

This ore forms a narrow vein in the southwest part of the town, on land of Moses Smith, two miles from the Congregational meeting-house. The direction of the vein is nearly north and south, and where I saw it, only a foot wide. The gangue is sulphate of barytes.

2. _Of Galena, Copper Pyrites, and Blende._

This vein is a little more than a mile north of the one above described, and it may be a continuation of the same vein. The gangue is nearly an equal admixture of sulphate of barytes and quartz; and galena and sulphuret of copper are disseminated through it in about the same, that is, equal proportions. The blende, which is of a yellowish aspect when the fractured crystal is held in a certain position, appears only occasionally. This vein is several feet wide, has been wrought to a small extent in two places, and its direction is nearly north and south. It is on land of Mr. Field.

_Radiated quartz._ In the above vein. A considerable tendency to crystallization appears at this place, not only in the quartz, but in the foliated structure of the barytes.

_Brown spar._ In the same place. But little of this mineral was noticed. It exfoliated before the blowpipe, turned black, and became magnetic.

3. _Of Specular Oxide of Iron in Montague._

This is found in a partially detached eminence, 100 feet high, near the north line of Montague, on land of Mr. Taft, a little southwest from the confluence of Miller's river with the Connecticut. The whole hill, not less than 100 rods in circumference at its base, is traversed by numerous veins of this ore; and scarcely a foot of the rock is to be seen that does not contain these, varying in width from a mere line to several inches. The principal vein appears on the top of the hill; and is, as nearly as I could determine, not less than ten feet wide, lying in a north and south direction. The ore seems to be abundant, and generally pure. Masses, that have been separated by blasting, and weighing from 100 to 200 pounds, lie on the surface. A small proportion of sulphuret of iron was observed in some specimens. The gangue is quartz, and the walls and hill granite.

No opinion is here intended to be offered concerning the probable value of these ores, if worked. If they be useless to the present generation, they may not be so to some future one, when labour shall be cheaper; and therefore it was thought to be of some consequence to point out their localities.

In the remarks, to which this paper is a supplement, _blue quartz_ was inadvertently put down among the minerals found in Deerfield. I presume it does not exist there. It is also probable that the variety of garnets found in Conway, is not, as formerly stated, the melanite.

7. _New Process for Tanning._

A process for effecting the tanning of leather in a neat, expeditious, and thorough manner, has been discovered by a Mr. Steel, of Connecticut: some account of it may be given hereafter.

8. _Connexion between Chemistry and Medicine._

This subject has been discussed in an able and interesting manner by Professor Cooper, of Philadelphia, in a public discourse, which has now been some months before the public.

9. _Brucite._

A new Species in Mineralogy, discovered by the late Dr. Bruce. We hope to publish in the next Number a description and analysis of it.

10. _Lithography._

We are promised for our next Number, a full account of this art, of which we have received a beautiful specimen, _A Minerva_, executed by Mr. Bates Otis, an ingenious and enterprising artist of Philadelphia, who, under the patronage of Dr. Samuel Brown, is preparing to disseminate the productions of his skill, and to make this important art (executed with American materials,) extensively useful in this country.

N. B. As this number has already much exceeded its proper size, we are obliged to suppress many articles of domestic, and all those of foreign intelligence.